# Patent

## Title
Methods and compositions for the treatment of eye disorders with increased intraocular pressure

## Abstract

The present invention relates to methods and compositions that decrease intraocular pressure (IOP) of the eye. The compositions of the invention comprise short interfering nucleic acid molecules (siNA) including, but not limited to, siRNA that decrease expression of genes associated with production or drainage of intraocular fluid. The compositions of the invention can be used in the preparation of a medicament for the treatment of eye conditions displaying increased IOP such as glaucoma, infection, inflammation, uveitis, and diabetic retinopathy. The methods of the invention comprise the administration to a patient in need thereof of an effective amount of one or more siNAs of the invention.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application U.S. Ser. No. 12/874,928, filed Sep. 2, 2010, now U.S. Pat. No. 8,389,490, which is a continuation of application U.S. Ser. No. 12/563,530, filed Sep. 21, 2009, now U.S. Pat. No. 7,902,169, which is a continuation of application U.S. Ser. No. 11/360,305, filed Feb. 22, 2006, now U.S. Pat. No. 7,592,325, which is a continuation-in-part of International Patent Application No. PCT/GB2005/050134, filed Aug. 23, 2005, which claims priority to British Application No. GB0503412.9, filed Feb. 18, 2005, and to British Application No. GB0418762.1, filed Aug. 23, 2004, the contents of each of which are incorporated by reference herein in their entirety.


1. FIELD OF THE INVENTION
The present invention relates to methods and compositions that decrease intraocular pressure (IOP) of the eye. The compositions of the invention comprise short interfering nucleic acid molecules (siNA) including, but not limited to, siRNA that decrease expression of genes associated with production or drainage of intraocular fluid. The compositions of the invention can be used in the preparation of a medicament for the treatment of an eye conditions displaying increased IOP such as glaucoma, infection, inflammation, uveitis, and diabetic retinopathy. The methods of the invention comprise the administration to a patient in need thereof an effective amount of one or more siNAs of the invention.
2. BACKGROUND OF THE INVENTION
Glaucoma is one of the leading causes of blindness. Approximately 15% of cases of blindness world-wide result from glaucoma. The most common type, primary open-angle glaucoma, has a prevalence of 1/200 in the general population over 40 years of age. Glaucoma has been simply defined as the process of ocular tissue destruction caused by a sustained elevation of the Intra Ocular Pressure (IOP) above its normal physiological limits. Although several etiologies may be involved in the glaucoma complex, an absolute determinant in therapy selection is the amount of primary and/or induced change in pressure within the iridocorneal angle.
Current therapies include medications or surgeries aimed at lowering this pressure, although the pathophysiological mechanisms by which elevated IOP leads to neuronal damage in glaucoma are unknown. Medical suppression of an elevated IOP can be attempted using four types of drugs: (1) the aqueous humor formation suppressors (such as carbonic anhydrase inhibitors, beta-adrenergic blocking agents, and alpha2-adrenoreceptor agonists); (2) miotics (such as parasympathomimetics, including cholinergics and anticholinesterase inhibitors); (3) uveoscleral outflow enhancers; and (4) hyperosmotic agents (that produce an osmotic pressure gradient across the blood/aqueous barrier within the cilliary epithelium). A fifth category of drugs, neuroprotection agents, is emerging as an important addition to medical therapy, including, for example, NOS inhibitors, excitatory amino acid antagonists, glutamate receptor antagonists, apoptosis inhibitors, and calcium channel blockers.
Reviews of various eye disorders and their treatments can be found in the following references: Bunce et al., 2005, Graefes Arch Clin Exp Ophthalmol.; 243(4):294; Costagliola et al., 2000, Exp Eye Res. 71(2):167; Costagliola et al., 1995, Eur J Ophthalmol., 5(1):19; Cullinane et al., 2002, Br J Ophthalmol., 86(6):676; Sakaguchi et al., 2002, Curr Eye Res. 24(5):325; Shah et al., 2000, J Cardiovasc Pharmacol., 36(2):169, and Wang et al., 2005, Exp Eye Res., 80(5):629.
RNA interference refers to the process of sequence-specific post-transcriptional gene silencing mediated by short interfering RNAs (siRNA). After the discovery of the phenomenon in plants in the early 1990s, Andy Fire and Craig Mello demonstrated that double-stranded RNA (dsRNA) specifically and selectively inhibited gene expression in an extremely efficient manner in Caenorhabditis elegans (Fire et al., 1998, Nature, 391:806). The sequence of the first strand (sense RNA) coincided with that of the corresponding region of the target messenger RNA (mRNA). The second strand (antisense RNA) was complementary to the mRNA. The resulting dsRNA turned out to be several orders of magnitude more efficient than the corresponding single-stranded RNA molecules (in particular, antisense RNA).
The process of RNAi begins when the enzyme, DICER, encounters dsRNA and chops it into pieces called small-interfering RNAs (siRNA). This protein belongs to the RNase III nuclease family. A complex of proteins gathers up these RNA remains and uses their code as a guide to search out and destroy any RNAs in the cell with a matching sequence, such as target mRNA (see Basher & Labouesse, 2000, Nat Cell Biol, 2000, 2(2):E31, and Akashi et al., 2001, Antisense Nucleic Acid Drug Dev, 11(6):359).
In attempting to utilize RNAi for gene knockdown, it was recognized that mammalian cells have developed various protective mechanisms against viral infections that could impede the use of this approach. Indeed, the presence of extremely low levels of viral dsRNA triggers an interferon response, resulting in a global non-specific suppression of translation, which in turn triggers apoptosis (Williams, 1997, Biochem Soc Trans, 25(2):509; Gil & Esteban, 2000, Apoptosis, 5(2): 107-14).
In 2000 dsRNA was reported to specifically inhibit 3 genes in the mouse oocyte and early embryo. Translational arrest, and thus a PKR response, was not observed as the embryos continued to develop (Wianny & Zemicka-Goetz, 2000, Nat Cell Biol, 2(2):70). Research at Ribopharma AG (Kulmbach, Germany) demonstrated the functionality of RNAi in mammalian cells, using short (20-24 base pairs) dsRNA to switch off genes in human cells without initiating the acute-phase response. Similar experiments carried out by other research groups confirmed these results. (Elbashir et al., 2001, Genes Dev, 15(2):188; Caplen et al., 2001, Proc. Natl. Acad. Sci. USA, 98: 9742) Tested in a variety of normal and cancer human and mouse cell lines, it was determined that short hairpin RNAs (shRNA) can silence genes as efficiently as their siRNA counterparts (Paddison et al, 2002, Genes Dev, 16(8):948). Recently, another group of small RNAs (21-25 base pairs) was shown to mediate downregulation of gene expression. These RNAs, small temporally regulated RNAs (stRNA), regulate timing of gene expression during development in Caenorhabditis elegans. (for review see Banerjee & Slack, 2002 and Grosshans & Slack, 2002, J Cell Biol, 156(1):17).
Scientists have used RNAi in several systems, including Caenorhabditis elegans, Drosophila, trypanosomes, and other invertebrates. Several groups have recently presented the specific suppression of protein biosynthesis in different mammalian cell lines (specifically in HeLa cells) demonstrating that RNAi is a broadly applicable method for gene silencing in vitro. Based on these results, RNAi has rapidly become a well-recognized tool for validating (identifying and assigning) gene function. RNAi employing short dsRNA oligonucleotides will yield an understanding of the function of genes that are only partially sequenced.
The preceding is a discussion of relevant art pertaining to RNAi. The discussion is provided only for understanding of the invention that follows, and is not an admission that any of the work described is prior art to the claimed invention.
3. SUMMARY OF THE INVENTION
The present invention relates to methods and compositions designed to decrease intraocular pressure (IOP) of the eye. The compositions of the invention can be used in the preparation of a medicament for the treatment of eye conditions displaying increased IOP such as, for example, glaucoma, infection, inflammation, uveitis, and diabetic retinopathy.
The compositions of the invention comprise short interfering nucleic acid molecules (siNA) that decrease or inhibit expression of genes associated with production or drainage of intraocular fluid. In one embodiment, siNAs of the invention decrease or inhibit expression of genes that are associated with production of intraocular fluid (e.g., aqueous humor). Examples of such genes that are targets of the invention include, but not limited to, Carbonic Anhydrases II, IV and XII; Adrenergic Receptors: beta 1 and 2 and alpha 1A, 1B and 1D; and ATPases: alpha 1, alpha 2, alpha 3, beta 1, beta 2. In another embodiment of the invention, siNAs of the invention decrease or inhibit expression of genes associated with drainage of intraocular fluid (e.g., aqueous humor). Examples of such genes that are targets of the invention include, but not limited to Acetylcholinesterase; Prostaglandin Endoperoxide Synthases 1 and 2; Selectin E; Angiotensin System: Angiotensin II, Angiotensin II Converting Enzymes (ACE I and ACE II), Angiotensin II Receptors (ATR1 and ATR2) and Renin; and Cochlin.
The present invention encompasses compositions and methods of use of short interfering nucleic acid (siNA) including, but not limited to, short interfering RNA (siRNA), double-stranded RNA (dsRNA), micro-RNA (miRNA), and short hairpin RNA (shRNA) molecules capable of mediating RNA interference (RNAi) against the target genes identified supra. In preferred embodiments, the siNA used in the methods of the invention are dsRNA. siNAs of the invention can be unmodified or chemically-modified.
The methods of the invention comprise the administration to a patient in need thereof of an effective amount of one or more siNAs of the invention. In embodiments where more than one type of siNA is administered, the siNAs can all be directed against the same or different target genes. In preferred embodiments, the methods of the invention provide a sustained decrease in IOP when compared with the duration of IOP decrease that results from administration of commercially available drugs (e.g., Xalatan, Trusopt, and Timoftol).
Methods of the invention also encompass administration of one or more siNAs of the invention in combination with one or more other therapeutics that decrease IOP including, but not limited to, commercially available drugs (e.g., Xalatan, Trusopt, and Timoftol).



4. BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the GenBank Accession Numbers corresponding to the selected human target genes.
FIGS. 2A-2Z, 2AA-2ZZ, 2AAA-2ZZZ, 2AAAA-2ZZZZ and 2AAAAA-2MMMMM show oligonucleotide sequences and their corresponding SEQ ID NOs. for siRNA molecules encompassed by the present invention. In FIGS. 2A-2Z, 2AA-2ZZ, 2AAA-2ZZZ, 2AAAA-2ZZZZ and 2AAAAA-2MMMMM, “CA4” indicates carbonic anhydrase IV, “CA2” indicates carbonic anhydrase II, “CA12” indicates carbonic anhydrase XII, “ADRB1” indicates adrenergic, beta-1-, receptor; “ADRB2” indicates adrenergic, beta-2-, receptor; “ACHE” indicates acetylcholinesterase; “SELE” indicates selectin E; “PTGS 1” indicates prostaglandin endoperoxide synthase 1; “PTGS2” indicates prostaglandin endoperoxide synthase 2; “ADRA1A” indicates adrenergic, alpha-1A-, receptor; “ADRA1B” indicates adrenergic, alpha-1B-, receptor; “ADRA1D” indicates adrenergic, alpha-1 D-, receptor; “AGT” indicates angiotensinogen; “AGTR1” indicates angiotensin II receptor, type 1; “AGTR2” indicates angiotensin II receptor, type 2; “ACE1” indicates angiotensin I converting enzyme 1; “ACE2” indicates angiotensin I converting enzyme 2; “REN” indicates renin; “COCH” indicates coagulation factor C homolog (cochlin); “ATP 1 A1” indicates ATPase, Na+/K+ transporting, alpha 1 polypeptide; “ATP1A2” indicates ATPase, Na+/K+ transporting, alpha 2 (+) polypeptide; “ATP1A3” indicates ATPase, Na+/K+ transporting, alpha 3 polypeptide; “ATP1B1” indicates ATPase, Na+/K+ transporting, beta 1 polypeptide; ATP1B2” indicates ATPase, Na+/K+ transporting, beta 2 polypeptide.
FIGS. 3A-3F show selected oligonucleotide sequences and their corresponding SEQ ID NOs. for siRNA molecules tested in vitro in human OMDC cells (“VTH”), in vitro in rabbit NPE cells (“VTR”), and/or in vivo (“VV”) experiments. All sequences are human unless otherwise specified (“Hom. to” indicates a rabbit sequence that is homologous to the indicated human sequence). SEQ ID NOS:1830-1833 are rabbit sequences with no corresponding disclosed human sequence.
FIGS. 4A-4B show the effect of siRNA on gene expression in an in vitro system. RNA was prepared from cells treated with an siRNA molecule and analyzed by semi-quantitative PCR. Semi-quantitative gels demonstrating expression for (A) the adrenergic, beta-2-, receptor (siRNA were SEQ ID NOs: 122 in lane 1, 125 in lane 2, and 139 in lane 3) or (B) acetylcholinesterase (siRNA were SEQ ID NOS: 162 in lane 1 and 167 in lane 2) are shown. Lower panels show levels of beta actin in the cells as a control. Lanes are as follows: M=molecular weight marker, C=control cells, TC=transfection control cells, 1-3=the different siRNAs used to inhibit expression, NC=negative control. “30c” indicates 30 PCR cycles and “40c” indicates 40 PCR cycles.
FIG. 5 shows the effect of inhibiting carbonic anhydrase II or carbonic anhydrase IV on IOP levels in rabbits in vivo. siRNA molecules targeting rabbit sequences for carbonic anhydrase II (SEQ ID NO:1838; homologous to SEQ ID NO: 73) and carbonic anhydrase IV (SEQ ID NO:5) were tested in an in vivo rabbit model. A 256 μg dose of the indicated siRNA was administered at time points indicated by an arrow. SEQ ID NO:73 decreased IOP by 25% while SEQ ID NO:5 decreased IOP by 16% over a saline control.
FIG. 6 shows the effect of inhibiting the adrenergic, beta-1-, receptor or the adrenergic, beta-2-, receptor on IOP levels in rabbits in vivo. siRNA molecules targeting rabbit sequences for the adrenergic, beta-1-, receptor (SEQ ID NO: 105) and the adrenergic, beta-2-, receptor (SEQ ID NO:1841; homologous to SEQ ID NO:139) were tested in an in vivo rabbit model. A 256 μg dose of the indicated siRNA was administered at time points indicated by an arrow. SEQ ID NO:105 decreased IOP by 25% while SEQ ID NO:139 decreased IOP by 22% over a saline control.
FIG. 7 shows the effect of inhibiting acetylcholinesterase on IOP levels in rabbits in vivo. A siRNA molecule targeting rabbit sequence for acetylcholinesterase (SEQ ID NO:1846; homologous to SEQ ID NO: 189) was tested in an in vivo rabbit model. A 256 μg dose of the siRNA was administered at time points indicated by an arrow. SEQ ID NO:189 decreased IOP by 25% over a saline control.
FIG. 8 shows the effect of inhibiting prostaglandin endoperoxide synthase 2 on IOP levels in rabbits in vivo. A siRNA molecule targeting rabbit sequence for a prostaglandin endoperoxide synthase 2 (SEQ ID NO: 426) was tested in an in vivo rabbit model. A 256 μg dose of the siRNA was administered at time points indicated by an arrow. SEQ ID NO:426 decreased IOP by 22% over a saline control.
FIGS. 9A-9D show the effect of inhibiting various molecules to decrease production or increase the drainage of intraocular fluid on IOP levels in rabbits in vivo. A siRNA molecule targeting either the human or rabbit sequence for the indicated target was tested in an in vivo rabbit model. A 256 μg dose of the siRNA was administered at time points indicated by an arrow. The targets were (A) ATPase, Na+/K+ transporting, alpha 1 polypeptide (SEQ ID NO: 1399), (B) ATPase, Na+/K+ transporting, beta 2 polypeptide (SEQ ID NO: 1820), (C) rabbit sequence of selectin E (SEQ ID NO:1848; homologous to SEQ ID NO: 262), (D) carbonic anhydrase XII (SEQ ID NO: 522). Effect of siRNAs are compared to saline controls.
FIG. 10 shows the dose dependent effect of inhibiting carbonic anhydrase II on IOP levels in rabbits in vivo. A siRNA molecule targeting the rabbit sequence for a carbonic anhydrase II (SEQ ID NO:1838; homologous to SEQ ID NO:73) was tested in an in vivo rabbit model. Either a 256 μg dose, a 132.5 μg dose, or a 66.25 μg dose of the siRNA was administered at time points indicated by an arrow.
FIG. 11 shows the effect of inhibiting the adrenergic, beta-2-, receptor with consecutive applications of siRNA on IOP levels in rabbits in vivo. A siRNA molecule targeting the rabbit sequence for the adrenergic, beta-2-, receptor (SEQ ID NO:1841; homologous to SEQ ID NO: 139) was tested in an in vivo rabbit model. A 256 μg dose of the siRNA was administered at time points indicated by an arrow. Effect of siRNA is compared to a saline control.
FIG. 12 shows the maximum decrease in IOP obtained in the rabbit in vivo model using the indicated siRNAs or commercially available drugs. siRNA molecules targeting the rabbit sequences for carbonic anhydrase II (SEQ ID NO:1838; homologous to SEQ ID NO: 73), carbonic anhydrase IV (SEQ ID NO: 5), the adrenergic, beta-2-, receptor (SEQ ID NO:1841; homologous to SEQ ID NO: 139), the adrenergic, beta-1-, receptor (SEQ ID NO: 105), acetylcholinesterase (SEQ ID NO:1846; homologous to SEQ ID NO:189), prostaglandin endoperoxide synthase 2 (SEQ ID NO:426) were administered in four doses of 256 μg each. The commercially available drugs Trusopt, Timoftol and Xalatan were administered in four doses of 8 mg, 1 mg, or 20 μg, respectively.
FIG. 13 shows a comparison of the effect of decreasing aqueous humor production with increasing drainage rate on IOP levels in rabbits in vivo. Aqueous humor production was decreased by inhibiting carbonic anhydrase II with siRNA and drainage rate was increased with the prostaglandin analog Xalatan. A 265 μg dose of either a siRNA molecule targeting the rabbit sequence for carbonic anhydrase II (SEQ ID NO:1838; homologous to SEQ ID NO: 73) or a 20 μg dose of the drug Xalatan were administered at time points indicated by an arrow to an in vivo rabbit model.
FIG. 14 shows a comparison in length of action of various siRNA treatments with commercially available drugs on IOP levels in rabbits in vivo. siRNA molecules targeting the rabbit sequences for carbonic anhydrase II (SEQ ID NO:1838; homologous to SEQ ID NO: 73), carbonic anhydrase IV (SEQ ID NO: 5), and the adrenergic, beta-2-, receptor (SEQ ID NO:1841; homologous to SEQ ID NO: 139) were administered in four doses of 256 μg each. The commercially available drugs Trusopt, Xalatan, and Timoftol were administered in four doses of 8 mg, 20 μg, or 1 mg, respectively.



5. DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to methods and compositions that decrease intraocular pressure (IOP) of the eye. The compositions of the invention comprise short interfering nucleic acid molecules (siNA) that decrease expression of genes associated with production or drainage of intraocular fluid (e.g., aqueous humor). The compositions of the invention can be used in the preparation of a medicament for the treatment of an eye conditions displaying increased IOP such as glaucoma, infection, inflammation, uveitis, and diabetic retinopathy. The methods of the invention comprise the administration to a patient in need thereof an effective amount of one or more siNAs of the invention.
5.1 Design of siNAs
siNAs of the invention are designed to modulate the activity by decreasing or inhibiting the expression of target genes that affect IOP. In one embodiment, a decrease in or inhibition of the target gene expression decreases the production of intraocular fluid (e.g., aqueous humor). Examples of such target genes are Carbonic Anhydrase H, Carbonic Anhydrase IV, Carbonic Anhydrase XII, Adrenergic Receptor beta 1, Adrenergic Receptor beta 2, Adrenergic Receptor alpha 1A, Adrenergic Receptor alpha 1B, Adrenergic Receptor alpha 1D, ATPase alpha 1, ATPase alpha 2, ATPase alpha 3, ATPase beta 1, and ATPase beta 2. In another embodiment, a decrease in or inhibition of the target gene expression increases the drainage of intraocular fluid (e.g., aqueous humor). Examples of such target genes are Acetylcholinesterase, Selectin E, Angiotensin II, Angiotensin II Converting Enzyme I, Angiotensin II Converting Enzyme II, Angiotensin II Receptor 1, Angiotensin 11 Receptor 2, Renin, Cochlin, Prostaglandin Endoperoxide Synthase 1, and Prostaglandin Endoperoxide Synthase 2. GenBank Accession numbers for preferred target genes are shown in FIG. 1.
A gene is “targeted” by a siNA according to the invention when, for example, the siNA molecule selectively decreases or inhibits the expression of the gene. The phrase “selectively decrease or inhibit” as used herein encompasses siNAs that affects expression of one gene as well those that effect the expression of more than one gene. In cases where an siNA affects expression of more than one gene, the gene that is targeted is effected at least two times, three times, four times, five times, ten times, twenty five times, fifty times, or one hundred times as much as any other gene. Alternatively, a siNA targets a gene when the siNA hybridizes under stringent conditions to the gene transcript. siNAs can be tested either in vitro or in vivo for the ability to target a gene.
A short fragment of the target gene sequence (e.g., 19-40 nucleotides in length) is chosen as the sequence of the siNA of the invention. In one embodiment, the siNA is a siRNA. In such embodiments, the short fragment of target gene sequence is a fragment of the target gene mRNA. In preferred embodiments, the criteria for choosing a sequence fragment from the target gene mRNA to be a candidate siRNA molecule include 1) a sequence from the target gene mRNA that is at least 50-100 nucleotides from the 5′ or 3′ end of the native mRNA molecule, 2) a sequence from the target gene mRNA that has a G/C content of between 30% and 70%, most preferably around 50%, 3) a sequence from the target gene mRNA that does not contain repetitive sequences (e.g., AAA, CCC, GGG, TTT, AAAA, CCCC, GGGG, TTTT), 4) a sequence from the target gene mRNA that is accessible in the mRNA, and 5) a sequence from the target gene mRNA that is unique to the target gene. The sequence fragment from the target gene mRNA may meet one or more of the criteria identified supra. In embodiments where a fragment of the target gene mRNA meets less than all of the criteria identified supra, the native sequence may be altered such that the siRNA conforms with more of the criteria than does the fragment of the target gene mRNA. In preferred embodiments, the siRNA has a G/C content below 60% and/or lacks repetitive sequences.
In some embodiments, each of the siNAs of the invention targets one gene. In one specific embodiment, the portion of the siNA that is complementary to the target region is perfectly complementary to the target region. In another specific embodiment, the portion of the siNA that is complementary to the target region is not perfectly complementary to the target region. siNA with insertions, deletions, and point mutations relative to the target sequence are also encompassed by the invention. Thus, sequence identity may calculated by sequence comparison and alignment algorithms known in the art (see Gribskov and Devereux, Sequence Analysis Primer, Stockton Press, 1991, and references cited therein) and calculating the percent difference between the nucleotide sequences by, for example, the Smith-Waterman algorithm as implemented in the BESTFIT software program using default parameters (e.g., University of Wisconsin Genetic Computing Group). Greater than 90%, 95%, or 99% sequence identity between the siNA and the portion of the target gene is preferred. Alternatively, the complementarity between the siNA and native RNA molecule may be defined functionally by hybridization. A siNA sequence of the invention is capable of hybridizing with a portion of the target gene transcript under stringent conditions (e.g., 400 mM NaCl, 40 mM PIPES pH 6.4, 1 mM EDTA, 50° C. or 70° C. hybridization for 12-16 hours; followed by washing). A siNA sequence of the invention can also be defined functionally by its ability to decrease or inhibit the expression of a target gene. The ability of a siNA to effect gene expression can be determined empirically either in vivo or in vitro.
In addition to siNAs which specifically target only one gene, degenerate siNA sequences may be used to target homologous regions of multiple genes. WO2005/045037 describes the design of siNA molecules to target such homologous sequences, for example by incorporating non-canonical base pairs, for example mismatches and/or wobble base pairs, that can provide additional target sequences. In instances where mismatches are identified, non-canonical base pairs (for example, mismatches and/or wobble bases) can be used to generate siNA molecules that target more than one gene sequence. In a non-limiting example, non-canonical base pairs such as UU and CC base pairs are used to generate siNA molecules that are capable of targeting sequences for differing targets that share sequence homology. As such, one advantage of using siNAs of the invention is that a single siNA can be designed to include nucleic acid sequence that is complementary to the nucleotide sequence that is conserved between homologous genes. In this approach, a single siNA can be used to inhibit expression of more than one gene instead of using more than one siNA molecule to target different genes.
Preferred siNA molecules of the invention are double stranded. In one embodiment, double stranded siNA molecules comprise blunt ends. In another embodiment, double stranded siNA molecules comprise overhanging nucleotides (e.g., 1-5 nucleotide overhangs, preferably 2 nucleotide overhangs). In a specific embodiment, the overhanging nucleotides are 3′ overhangs. In another specific embodiment, the overhanging nucleotides are 5′ overhangs. Any type of nucleotide can be a part of the overhang. In one embodiment, the overhanging nucleotide or nucleotides are ribonucleic acids. In another embodiment, the overhanging nucleotide or nucleotides are deoxyribonucleic acids. In a preferred embodiment, the overhanging nucleotide or nucleotides are thymidine nucleotides. In another embodiment, the overhanging nucleotide or nucleotides are modified or non-classical nucleotides. The overhanging nucleotide or nucleotides may have non-classical internucleotide bonds (e.g., other than phosphodiester bond).
In preferred embodiments, siNA compositions of the invention are any of SEQ ID NOS:1-1829. In an even more preferred embodiments, dsRNA compositions of the invention are any of SEQ ID NOS:1-1829 hybridized to its complement. The invention also encompasses siNAs that are 40 nucleotides or less and comprise a nucleotide sequence of any of SEQ ED NOS:1-1829 as well as dsRNA compositions that are 40 nucleotides or less and comprise a nucleotide sequence of any of SEQ ID NOS:1-1829 hybridized to its complement. In a specific embodiment, the siNA is 21-30 nucleotides and comprises any one of SEQ ID NOS:1-1829.
5.2 Synthesis of siNAs
siNAs designed by methods described in Section 5.1 can be synthesized by any method known in the art. RNAs are preferably chemically synthesized using appropriately protected ribonucleoside phosphoramidites and a conventional DNA/RNA synthesizer. Additionally, siRNAs can be obtained from commercial RNA oligo synthesis suppliers, including, but not limited to, Proligo (Hamburg, Germany), Dharmacon Research (Lafayette, Colo., USA), Glen Research (Sterling, Va., USA), ChemGenes (Ashland, Mass., USA), and Cruachem (Glasgow, UK), Qiagen (Germany), Ambion (USA) and Invitrogen (Scotland). Alternatively, siNA molecules of the invention can be expressed in cells by transfecting the cells with vectors containing the reverse complement siNA sequence under the control of a promoter. Once expressed, the siNA can be isolated from the cell using techniques well known in the art.
In embodiments where the siRNA is a dsRNA, an annealing step is necessary if single-stranded RNA molecules are obtained. Briefly, combine 30 μl of each RNA oligo 50 μM solution in 100 mM potassium acetate, 30 mM HEPES-KOH pH 7.4, 2 mM magnesium acetate. The solution is then incubated for 1 minute at 90° C., centrifuged for 15 seconds, and incubated for 1 hour at 37° C.
In embodiments where the siRNA is a short hairpin RNA (shRNA); the two strands of the siRNA molecule may be connected by a linker region (e.g., a nucleotide linker or a non-nucleotide linker).
5.3 Chemical Modification of siNAs
The siNAs of the invention may contain one or more modified nucleotides and/or non-phosphodiester linkages. Chemical modifications well known in the art are capable of increasing stability, availability, and/or cell uptake of the siNA. The skilled person will be aware of other types of chemical modification which may be incorporated into RNA molecules (see International Publications WO031070744 and WO2005/045037 for an overview of types of modifications).
In one embodiment, modifications can be used to provide improved resistance to degradation or improved uptake. Examples of such modifications include phosphorothioate internucleotide linkages, 2′-0-methyl ribonucleotides (especially on the sense strand of a double stranded siRNA), 2′-deoxy-fluoro ribonucleotides, 2′-deoxy ribonucleotides, “universal base” nucleotides, 5-C-methyl nucleotides, and inverted deoxyabasic residue incorporation (see generally GB2406568).
In another embodiment, modifications can be used to enhance the stability of the siRNA or to increase targeting efficiency. Modifications include chemical cross linking between the two complementary strands of an siRNA, chemical modification of a 3′ or 5′ terminus of a strand of an siRNA, sugar modifications, nucleobase modifications and/or backbone modifications, 2′-fluoro modified ribonucleotides and 2′-deoxy ribonucleotides (see generally International Publication WO2004/029212).
In another embodiment, modifications can be used to increase or decrease affinity for the complementary nucleotides in the target mRNA and/or in the complementary siNA strand (see generally International Publication WO2005/044976). For example, an unmodified pyrimidine nucleotide can be substituted for a 2-thio, 5-alkynyl, 5-methyl, or 5-propynyl pyrimidine. Additionally, an unmodified purine can be substituted with a 7-deza, 7-alkyl, or 7-alkenyl purine.
In another embodiment, when the siNA is a double-stranded siRNA, the 3′-terminal nucleotide overhanging nucleotides are replaced by deoxyribonucleotides (see generally Elbashir et al., 2001, Genes Dev, 15:188).
5.4 Demonstration of Therapeutic Utility
The compositions and methods of the invention are preferably tested in vitro, and then in vivo, for the desired therapeutic activity prior to use in humans. For example, in vitro assays which can be used to determine whether administration of a specific therapeutic protocol is indicated, include in vitro cell culture assays in which a candidate siNA is administered to cells (e.g., rabbit non-pigmented cilliary epithelium cells (NPE), human cilliary epithelium cells (OMDC), or human embryonic kidney cells (HEK293)) in vitro and the effect of such protocol upon the cells is observed, e.g., decreased or inhibited expression of the target gene.
Compounds for use in therapy can be tested in suitable animal model systems prior to testing in humans, including but not limited to in rabbits, rats, mice, chicken, cows, monkeys, hamsters, etc. For example, the New Zealand rabbit is the preferred standard in experimental platforms designed to study IOP. It is easy to handle and it has a big eye, similar in size to the human organ. In addition, present equipment to measure IOP is not suited to use in animals with small eyes such as mice or rats. Finally, rabbits have an IOP (about or equal to 23 mm Hg) that can be reduced to 40% of its normal (or pre-drug) value (e.g., to about or equal to 9 mm Hg) using local commercial hypotensive medication. Thus, although it is possible to generate rabbit glaucoma models (for example, surgically blocking episclerotic veins or artificially occluding the trabecular meshwork), generally those in the field use normotensive rabbits.
5.5 Therapeutic Methods
The present invention encompasses methods for treating, preventing, or managing an eye disorder associated with increased IOP in a patient (e.g., a mammal, especially humans) comprising administering an effective amount of one or more siNAs of the invention. In a specific embodiment, the disorder to be treated, prevented, or managed is glaucoma. Any type of glaucoma that is associated with IOP can be treated with the methods of the present invention including, but not limited to, Open Angle Glaucoma (e.g., Primary Open Angle Glaucoma, Pigmentary Glaucoma, and Exfoliative Glaucoma, Low Tension Glaucoma), Angle Closure Glaucoma (also known clinically as closed angle glaucoma, narrow angle glaucoma, pupillary block glaucoma, and ciliary block glaucoma) (e.g., Acute Angle Closure Glaucoma and Chronic Angle Closure Glaucoma), Aniridic Glaucoma, Congenital Glaucoma, Juvenile Glaucoma, Lens-Induced Glaucoma, Neovascular Glaucoma, Post-Traumatic Glaucoma, Steroid-Induced Glaucoma, Sturge-Weber Syndrome Glaucoma, and Uveitis-Induced Glaucoma.
In preferred embodiments, the siNAs used in the therapeutic methods of the invention decrease or inhibit the expression of genes that effect IOP, for example, Carbonic Anhydrase II, Carbonic Anhydrase IV, Carbonic Anhydrase XII, Adrenergic Receptor beta 1, Adrenergic Receptor beta 2, Adrenergic Receptor alpha 1A, Adrenergic Receptor alpha 1B, Adrenergic Receptor alpha 1D, ATPase alpha 1, ATPase alpha 2, ATPase alpha 3, ATPase beta 1, and ATPase beta 2, Acetylcholinesterase, Selectin E, Angiotensin H, Angiotensin II Converting Enzyme I, Angiotensin II Converting Enzyme II, Angiotensin II Receptor 1, Angiotensin II Receptor 2, Renin, Cochlin, Prostaglandin Endoperoxide Synthase 1, and Prostaglandin Endoperoxide Synthase 2. In certain embodiments, one or more of the siNAs of the invention are selected from the group consisting of SEQ ID NOS:1-1829. In a specific preferred embodiment, the siNAs used in the therapeutic methods of the invention are dsRNA of any of SEQ ID NOS:1-1829 hybridized to its complement. The invention also encompasses siNAs that are 40 nucleotides or less and comprise a nucleotide sequence of any of SEQ ID NOS:1-1829 as well as dsRNA compositions that are 40 nucleotides or less and comprise a nucleotide sequence of any of SEQ ID NOS:1-1829 hybridized to its complement. In a specific embodiment, the siNA is 21-30 nucleotides and comprises any of SEQ ID NOS:1-1829.
In preferred embodiments, the methods of the invention provide a sustained decrease in IOP that lasts for longer than 8, 10, 12, or 14 hours, more preferably for several days (e.g., 2 days, 3 days, 4 days, or 5 days), after the last administration of siNA. In such embodiments, the effect (i.e., decreased IOP) of administered siNAs of the invention is longer lasting than the duration of IOP decrease that typically results from administration of presently commercially available drugs (e.g., Xalatan, Trusopt, and Timoftol). The siNAs of the invention that provide sustained IOP decreasing action can be administered in a regimen such that IOP is continually decreased without daily administration of the siNA. In a specific embodiment, a treatment regimen can include consecutive cycles of administration (e.g., one dose of siNA given daily for four days) and non-administration (e.g., 3 or 4 days with no treatment given) while still eliciting a continual decrease in IOP.
In one embodiment, a single type of siNA is administered in the therapeutic methods of the invention. In another embodiment, an siNA of the invention is administered in combination with another siNA of the invention and/or with one or more other non-siNA therapeutic agents useful in the treatment, prevention or management of an eye disorder associated with increased IOP. The term “in combination with” is not limited to the administration of therapeutic agents at exactly the same time, but rather it is meant that the siNAs of the invention and the other agent are administered to a patient in a sequence and within a time interval such that the benefit of the combination is greater than the benefit if they were administered otherwise. For example, each therapeutic agent may be administered at the same time or sequentially in any order at different points in time; however, if not administered at the same time, they should be administered sufficiently close in time so as to provide the desired therapeutic effect. Each therapeutic agent can be administered separately, in any appropriate form and by any suitable route.
5.6 Dosage
As used herein, an “effective amount” refers to that amount of a siNA of the invention sufficient to treat or manage an eye disorder associated with increased IOP and, preferably, the amount sufficient to decrease IOP. For treatment of increased IOP in humans, it is preferred to reduce IOP so that IOP is between about 14 and 20 mm Hg. However, any reduction in IOP as compared to pretreatment IOP is advantageous (e.g., a decrease in IOP greater that 5%, 10%, 25%, 30%, 35%, 40%, 50%, or 60% of pretreatment IOP). A therapeutically effective amount may also refer to the amount of an siNA sufficient to delay or minimize the onset of an eye disorder associated with IOP. A therapeutically effective amount may also refer to the amount of the therapeutic agent that provides a therapeutic benefit in the treatment or management of an eye disorder associated with IOP. Further, a therapeutically effective amount with respect to an siNA of the invention means that amount of therapeutic agent alone, or in combination with other therapies, that provides a therapeutic benefit in the treatment or management of an eye disorder associated with IOP. Used in connection with an amount of an siRNA of the invention, the term can encompass an amount that improves overall therapy, reduces or avoids unwanted effects, or enhances the therapeutic efficacy of or synergies with another therapeutic agent. Treatment with siNA alone or in combination should result in an IOP of about 14 and 20 nun Hg. However, any decrease in IOP as compared to pretreatment IOP is advantageous (e.g., a decrease in IOP greater that 5%, 10%, 25%, 30%, 35%, 40%, 50%, or 60% of pretreatment IOP).
The effective amount of a composition of the invention can be determined by standard research techniques. For example, the dosage of the composition which will be effective in the treatment, prevention or management of the disorder can be determined by administering the composition to an animal model such as, e.g., the animal models disclosed herein or known to those skilled in the art. In addition, in vitro assays may optionally be employed to help identify optimal dosage ranges. Alternatively, the dosage may be determined for an individual by titrating the dose until an effective level is reached.
Selection of the preferred effective amount to be used in dosages can be determined (e.g., via clinical trials) by a skilled artisan based upon the consideration of several factors which will be known to one of ordinary skill in the art. Such factors include the disorder to be treated or prevented, the symptoms involved, the patient's body mass, the patient's immune status and other factors known by the skilled artisan to reflect the accuracy of administered pharmaceutical compositions.
The precise dose to be employed in the formulation will also depend on the route of administration, and the seriousness of the disorder, and should be decided according to the judgment of the practitioner and each patient's circumstances. Effective doses may be extrapolated from dose-response curves derived from in vitro or animal model test systems.
When the siRNA is administered directly to the eye, generally an amount of between 0.3 mg/kg-20 mg/kg, 0.5 mg/kg-10 mg/kg, or 0.8 mg/kg-2 mg/kg body weight/day of siNA is administered. When the siRNA is administered intravenously, generally an amount of between 0.5 mg-20 mg, or 0.8 mg-10 mg, or 1.0 mg-2.0 mg/injection is administered.
5.7 Formulations and Routes of Administration
The siNAs of the invention may be formulated into pharmaceutical compositions by any of the conventional techniques known in the art (see for example, Alfonso, G. et al., 1995, in: The Science and Practice of Pharmacy, Mack Publishing, Easton Pa., 19th ed.). Formulations comprising one or more siNAs for use in the methods of the invention may be in numerous forms, and may depend on the various factors specific for each patient (e.g., the type and severity of disorder, type of siNA administered, age, body weight, response, and the past medical history of the patient), the number and type of siNAs in the formulation, the form of the composition (e.g., in liquid, semi-liquid or solid form), the therapeutic regime (e.g. whether the therapeutic agent is administered over time as a slow infusion, a single bolus, once daily, several times a day or once every few days), and/or the route of administration (e.g., topical, oral, intravenous, intramuscular, intra-arterial, intramedullary, intrathecal, transdermal, subcutaneous, intraperitoneal, intranasal, enteral, or sublingual means).
These compositions can take the form of aqueous and non aqueous solutions, suspensions, emulsions, microemulsions, aqueous and non aqueous gels, creams, tablets, pills, capsules, powders, sustained-release formulations and the like. The siNAs of the invention can also be encapsulated in a delivery agent (including, but not limited to, liposomes, microspheres, microparticles, nanospheres, nanoparticles, biodegradable polymers, hydrogels, cyclodextrins poly (lactic-co-glycolic) acid (PLGA)) or complexed with polyethyleneimine and derivatives thereof (such as polyethyleneimine-polyethyleneglycol-N-acetylgalactosamine (PEI-PEG-GAL) or polyethyleneimine-polyethyleneglycol-tri-N-acetylgalactosamine (PEI-PEG-triGAL) derivatives).
Pharmaceutical carriers, vehicles, excipients, or diluents may be included in the compositions of the invention including, but not limited to, water, saline solutions, buffered saline solutions, oils (e.g., petroleum, animal, vegetable or synthetic oils), starch, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodium chloride, dried skim milk, glycerol, propylene, glycol, ethanol, biopolymers (e.g., carbopol, haluronic acid, polyacrylic acid, etc.), dextrose, permeation enhancers (e.g., fatty acids, fatty acid esters, fatty alcohols and amino acids), and hydrophilic polymers (e.g., polycarbophil and polyvinylpyrolidone) and the like. The composition, if desired, can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents.
Pharmaceutical formulations suitable for parenteral administration may be formulated in aqueous solutions, preferably in physiologically compatible buffers such as Hanks' solution, Ringer's solution, or physiologically buffered saline. Aqueous injection suspensions may contain substances, which increase the viscosity of the suspension, such as sodium carboxymethyl cellulose, sorbitol, or dextran. In addition, suspensions of the active compounds may be prepared as appropriate oily injection suspensions. Suitable lipophilic solvents or vehicles include fatty oils such as sesame oil, or synthetic fatty acid esters, such as ethyloleate or triglycerides, or liposomes. Optionally, the suspension may also contain suitable stabilizers or agents which increase the solubility of the compounds to allow for the preparation of highly concentrated solutions.
Pharmaceutical compositions can be administered systemically or locally, e.g., near the intended site of action (i.e., the eye). Additionally, systemic administration is meant to encompass administration that can target to a particular area or tissue type of interest.
In preferred embodiments, the compositions of the invention are formulated in a solution or a gel for topical administration to the eye. In such embodiments, the formulations may be cationic emulsions and/or contain biopolymers including, but not limited to, poly(lactide-co-glycolide), carbopol, haluronic acid and polyacrylic acid.
The siNAs of the present invention can also be formulated in combination with other therapeutic compounds that decrease IOP (e.g., commercially available drugs).
Alternatively, the siNAs can be expressed directly in cells of interest (e.g., the eye, more particularly cells of the trabecular meshwork or pigmented cilliary epithelium cells) by transfecting the cells with vectors containing the reverse complement siNA sequence under the control of a promoter. For double stranded siNAs, cells can be transfected with one or more vectors expressing the reverse complement siNA sequence for each strand under the control of a promoter. The cell of interest will express the siNA directly without having to be administered a composition of the invention.
The contents of all published articles, books, reference manuals and abstracts cited herein, are hereby incorporated by reference in their entirety to more fully describe the state of the art to which the invention pertains.
As various changes can be made in the above-described subject matter without departing from the scope and spirit of the present invention, it is intended that all subject matter contained in the above description, or defined in the appended claims, be interpreted as descriptive and illustrative of the present invention. Modifications and variations of the present invention are possible in light of the above teachings.
6. EXAMPLES
6.1 Design of siRNAs
For each gene target, several siNA molecules were designed using proprietary software. The proprietary software used a number of criteria in choosing a sequence fragment of a gene as a candidate siRNA molecule including 1) a sequence from the target gene mRNA that is at least 50-100 nucleotides from the 5′ or 3′ end of the native mRNA molecule, 2) a sequence from the target gene mRNA that has a G/C content of between 30% and 70%, most preferably around 50%, 3) a sequence from the target gene mRNA that does not contain repetitive sequences (e.g., AAA, CCC, GGG, TTT, AAAA, CCCC, GGGG, TTTT), 4) a sequence from the target gene mRNA that is accessible in the mRNA, and 5) a sequence from the target gene mRNA that is unique to the target gene.
Briefly, each of the target genes was introduced as a nucleotide sequence in a prediction program that takes into account all the variables described supra for the design of optimal oligonucleotides for use as siRNA. This program scanned any mRNA nucleotide sequence for regions susceptible to be targeted by siRNAs and thus were good candidates for use as the sequence of the siRNA molecule itself. The output of this analysis was a score of possible siRNA oligonucleotides. The highest scores were used to design double stranded RNA oligonucleotides (typically 19 bp long) that were typically made by chemical synthesis.
Target genes are listed with their GenBank Accession numbers in FIG. 1. siRNA molecules directed to the target genes are listed in FIGS. 2A-2Z, 2AA-2ZZ, 2AAA-2ZZZ, 2AAAA-2ZZZZ and 2AAAAA-2MMMMM. All siRNA molecules used in the experiments described infra were designed to have a 2 thymidine nucleotide 3′ overhang. Some of the siRNA molecules were designed to target rabbit homologs of human target genes in preparation for in vivo assays in a rabbit model. Those siRNAs targeting rabbit genes are identified in FIGS. 3A-3F with “Hom. to” indicating the human siRNA that each is homologous to. Specifically, SEQ ID NOS:1834-1862 are rabbit homologs of human sequences. Four siRNAs tested, SEQ ID NOS:1830-1833, do not have a corresponding human homologous sequence.
6.2 In Vitro Assays
Cells (either NPE, OMDC, or HEK293 cells) were incubated with various siRNA molecules and assayed for expression of the native mRNA corresponding to the siRNA molecule. One day prior to transfection, 2−4×105 cells were seeded into each well of a 6 well plate in 3 ml of growth medium (DMEM, 10% serum, antibiotics and glutamine) and incubated under normal growth conditions (37° C. and 5% CO2). Lipofectamine 2000 Reagent (Invitrogen Corporation, Carlsbad, Calif.) was used to transfect the cells with the siRNA molecules. The protocol supplied by the manufacturer was followed. Briefly, siRNA molecules were added to cells that were 30%-50% confluent to a final concentration of 100 nM. Prior to addition to the cells, the siRNA molecule was diluted in 250 μl DMEM and incubated at room temperature for 5 minutes. The siRNA was then mixed with 6 μl of Lipofectamine 2000 Reagent that also had been diluted in 250 μl DMEM and the mixture was incubated at room temperature for 20 minutes. The siRNA/Lipofectamine mixture was added to the cells drop-wise with 2 ml of fresh growth medium low in antibiotics. After swirling the plates to ensure uniform distribution of the transfection complexes, the cells were incubated under normal growth conditions for 24 hours. After incubation with either of the transfection complexes, the medium was removed and replaced with 3 ml of fresh complete growth medium. mRNA was collected from cells at 24, 48 and 72 hours post-transfection.
After transfection and incubation with a siRNA molecule, total RNA fractions were extracted from cells using protocols well known in the art. The effect of siRNAs on target gene expression was analyzed by real time PCR and semi-quantitative PCR according to standard protocols. Approximately 250 ng of total RNA was used for reverse transcription followed by PCR amplification with specific primers for the target gene in a reaction mixture containing SYBR Green I Dye (Applied Biosystems, Foster City, Calif.). Basic PCR conditions comprised an initial step of 30 minutes at 91° C., followed by 40 cycles of 5 s at 95° C., 10 s at 62° C. and 15 s at 72° C. Quantification of beta-actin mRNA was used as a control for data normalization.
Table 1 shows representative results of real time PCR experiments for some of the target genes. The values represent the mean of the percentage of siRNA interference of each gene expression once normalized with the control cells and their standard deviations. Compared to the control cells, the level of the different transcripts at both 24 and 48 h time points was significantly reduced after the siRNA treatment.









TABLE 1








% of gene transcript level




in control cells













Target
siRNA used
24 h
48 h






CA2
SEQ ID NO: 73
76.25 ± 12.60
84.57 ± 14.70




SEQ ID NO: 54
37.97 ± 9.78
61.45 ± 9.62




SEQ ID NO: 66
35.30 ± 9.73
51.14 ± 16.49



PTGS1
SEQ ID NO: 353
42.25 ± 13.76
42.68 ± 17.00




SEQ ID NO: 369
34.98 ± 14.33
26.30 ± 10.91



PTGS2
SEQ ID NO: 426
68.68 ± 12.48
70.17 ± 19.21




SEQ ID NO: 421
81.00 ± 13.54
66.85 + 18.67




SEQ ID NO: 477
75.45 ± 14.71
61.83 ± 16.96









FIGS. 4A and 4B show the effect of siRNA on gene expression for the adrenergic, beta-2-, receptor (FIG. 4A) and acetylcholinesterase (FIG. 4B). The siRNA molecules used for each were SEQ ID NOs: 122, 125, and 139 for the adrenergic, beta-2-, receptor (lanes 1-3 of FIG. 4A, respectively) and SEQ ID NOs: 162 and 167 for acetylcholinesterase (in lanes 1-2 of FIG. 4B, respectively). Lower panels show levels of beta actin in the cells as a control. “Control cells” were nontransfected NPE cells, “transfection control cells” were NPE cells transfected with an siRNA with a scrambled sequence, and “negative control cells” were a PCR control. Either 30 (indicated by “30c”) or 40 (indicated by “40c”) PCR cycles were run.
6.3 In Vivo Assays
Normotensive New Zealand White rabbits (males, 2-3 kg) were used in the in vivo assays. The animals were kept in individual cages with free access to food and water. Animals were submitted to artificial 12 hours light/darkness cycles to avoid uncontrolled circadian oscillations of IOP and all experiments were performed at the same time of day to control for any fluctuations in IOP due to circadian oscillations. Animal handling and treatment were carried out in accordance with the European Communities Council Directive (86/609/EEC) and the statement of the Association for Research in Vision and Ophthalmology on the Use of Animals in Ophthalmic and Vision Research. Each animal was used for only one experiment.
IOP measurements were done using a contact tonometer (TonoPen XL, Mentor, Norwell, Mass.) due to past success of measuring intraocular pressures within the range of 3 to 30 mm Hg in rabbits (Abrams et al., 1996, Invest Ophthalmol Vis Sci. 37:940-4). Measurements were performed by delicately applying the tonometer's sensor to the corneal surface of the animal. All measurements fell within the 3 to 30 mm Hg interval with the mean baseline value of intraocular pressure being 17.0±0.39 mm Hg for untreated animals (n=100). In order to avoid distress to the animal, rabbits were topically anesthetized (10 μl of oxibuprocaine/tetracaine, 0.4%/1%, in a saline solution (1/4 v:v)) prior to IOP measurement.
Commercially available drugs were typically administered to the animals by instilling a small volume (typically 40 μl) on the corneal surface. Contralateral eyes were treated with the vehicle alone and were used as controls in each experiment.
siRNA molecules or commercially available drugs were typically administered to the animals as follows. Doses of siRNA in saline solution (0.9% w/v) to a final volume of 40 μl were applied to the corneal surface of one eye each day during four consecutive days. The opposite eye was taken as a control and 40 μl of sterile saline (0.9% w/v) was instilled on it at the same time points. Commercially available drugs were typically administered to the animals by instilling a small volume (typically 40 μl) on the corneal surface. Contralateral eyes were treated with the vehicle alone and were used as controls in each experiment. The IOP was measured before each application and at 2 h, 4 h and 6 h following the instillation for 10 days.
The data are summarized in Table 2 where values represent the mean of the normalized maximum percentage of IOP reduction after siRNA treatment and their standard deviations. The decrease in IOP was statistically significant for all the treated targets. These results indicated that both siRNAs and commercial drugs reduced IOP levels around 20%, although siRNAs presented a more maintained effect. No secondary effects were observed in the animals during the experimental protocols.










TABLE 2








IOP Reduction



Target
siRNA used
(% of saline control)








CA2
SEQ ID NO: 1838
24.84 ± 3.41




(Hom. To SEQ ID NO: 73)




CA4
SEQ ID NO: 5
14.47 ± 5.00



CA12
SEQ ID NO: 522
24.30 ± 1.29



ADRB1
SEQ ID NO: 105
28.04 ± 2.98



ADRB2
SEQ ID NO: 1841
21.18 ± 1.88




(Hom. To SEQ ID NO: 139)




ADRAIA
SEQ ID NO: 1856
 9.51 ± 1.04




(Hom. To SEQ ID NO: 546)




ADRAM
SEQ ID NO: 1858
17.48 ± 1.30




(Hom. To SEQ ID NO: 619)




ACHE
SEQ ID NO: 1846
25.25 ± 2.70




(Hom. To SEQ ID NO: 189)




PTGS1
SEQ ID NO: 1850
14.62 ± 1.93




(Hom. To SEQ ID NO: 322)




PTGS2
SEQ ID NO: 426
23.78 ± 2.27



SELE
SEQ ID NO: 1848
21.80 ± 1.74




(Hom. To SEQ ID NO: 262)




ACE1
SEQ ID NO: 1860
17.51 ± 1.28




(Hom. To SEQ ID NO: 866)




AGTR1
SEQ ID NO: 1859
 9.72 ± 1.35




(Hom. To SEQ ID NO: 705)




AGTR2
SEQ ID NO: 774
11.22 ± 1.53



ATP1A1
SEQ ID NO: 1399
18.13 ± 1.39



ATP1B2
SEQ ID NO: 1820
16.32 ± 0.91



Xalatan
—
25.46 ± 5.24



Trustop
—
16.41 ± 2.38





i. “Hom. To” indicates that the siRNA used was the rabbit homolog of the indicated human sequence






FIGS. 5-9 show time course experiments over 10 days for the indicated siRNAs using the in vivo rabbit model of IOP. The indicated siRNA was administered one time on each of days 1-4 of the experiment. Maximum responses (i.e., decrease in IOP) were generally observed on day 2 or 3 of the experiment and lasted for several days.
FIG. 10 shows the dose dependent effect of inhibiting carbonic anhydrase II on IOP levels in the in vivo rabbit model. Either a 265 μg, 132.5 μg, or 66.25 μg dose of the indicated siRNA was administered on each of days 1-4 of the ten day experiment. Although all levels of dose decreased IOP, there was a greater degree of decrease with increasing amounts of siRNA used.
FIG. 11 shows the effect of inhibiting the adrenergic, beta-2-, receptor with consecutive applications of siRNA on IOP levels in the in vivo rabbit model. The indicated siRNA was administered one time on each of days 1-4, 7-10, and 15-18 of the twenty eight day experiment. Decreased levels of IOP were maintained with administration schemes at 3 day intervals.
FIG. 12 shows a comparison of the maximum decrease in IOP in the in vivo rabbit model using the indicated siRNAs and commercially available drugs. For the siRNAs and drugs that decrease aqueous humor production, all of the siRNAs elicited a maximum decrease in IOP greater than that of Trusopt but less than that of Timoftol. For the siRNAs and drugs that increased drainage rate, all of the siRNAs elicited a maximum decrease in IOP greater than that of Xalatan.
FIG. 13 shows a time course experiment over 10 days for the indicated siRNA and drug using the in vivo rabbit model of IOP. The indicated siRNA or drug was administered one time on each of days 1-4 of the experiment. Maximum responses (i.e., decrease in IOP) were generally observed on day 2 or 3 of the experiment for the siRNA but were more immediate for the drug. Although the drug acted more quickly than siRNA in decreasing IOP, it only maintained an effect for about 8 hours whereas the effect of the siRNA lasted several days.
FIG. 14 shows a comparison in length of action of various siRNA treatments with commercially available drugs on IOP levels in the in vivo rabbit model. The indicated siRNA or drug was administered in four doses (one dose each on four consecutive days) and the IOP was measured four times a day during days 0-10. The Effect50 represents the time interval between the moment when the IOP reaches a value which is 50% of the maximum decrease reached and the moment when the IOP level starts to recover to values higher than 50% of the maximum decrease value. All of the siRNAs tested decreased IOP for a longer period of time than any of the drugs.

## Claims

1. An isolated nucleic acid molecule consisting essentially of a double stranded, short interfering ribonucleic acid (siRNA) of 19 nucleotides in length, wherein the nucleotide sequence of one strand of the siRNA is the sequence as set forth in SEQ ID NO:139 or SEQ ID NO: 1841, which isolated siRNA specifically targets adrenergic beta receptor 2.

2. The isolated nucleic acid molecule according to claim 1, wherein the siRNA is short hairpin (shRNA).

3. The isolated nucleic acid molecule according to claim 1, wherein the siRNA comprises at least one modified oligonucleotide.

4. The isolated nucleic acid molecule according to claim 1, wherein the siRNA comprises at least one linkage between two nucleotides that is not a phosphodiester linkage.

5. The isolated nucleic acid molecule according to claim 1, wherein the nucleotide sequence of one strand of the siRNA is the sequence as set forth in SEQ ID NO: 139.

6. The isolated nucleic acid molecule according to claim 1, wherein the nucleotide sequence of one strand of the siRNA is the sequence as set forth in SEQ ID NO: 1841.

7. An isolated nucleic acid molecule consisting essentially of a double stranded, short interfering RNA (siRNA), wherein the nucleotide sequence of one strand of the siRNA is the sequence as set forth in SEQ ID NO: 139 or SEQ ID NO: 1841, which siRNA specifically targets adrenergic beta receptor 2 and has a dinucleotide 3′ overhang.

8. The isolated nucleic acid molecule according to claim 7, wherein the nucleotide sequence of one strand of the siRNA is the sequence as set forth in SEQ ID NO: 139.

9. The isolated nucleic acid molecule according to claim 7, wherein the nucleotide sequence of one strand of the siRNA is the sequence as set forth in SEQ ID NO: 1841.

10. The isolated nucleic acid molecule according to claim 7, wherein the dinucleotide 3′ overhang comprises thymidine (T) nucleotides.

11. The isolated nucleic acid molecule according to claim 7, wherein the siRNA is short hairpin (shRNA).

12. The isolated nucleic acid molecule according to claim 7, wherein the siRNA comprises at least one modified oligonucleotide.

13. The isolated nucleic acid molecule according to claim 7, wherein the siRNA comprises at least one linkage between two nucleotides that is not a phosphodiester linkage.