bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preferential increase in splanchnic sympathetic activity induced by hepatic cirrhosis in rats
Authors: Estrela Heder Frank Gianotto , Castro Eduardo Ferreira , Naffah-Mazzacoratti Maria da Graça , Bergamaschi Cassia Toledo , Campos Ruy Ribeiro 
Published: June 2021

Increased sympathetic activity and arterial hypotension are found in cirrhotic patients. The aim of this study was to evaluate the control of renal (rSNA) and splanchnic (sSNA) sympathetic nerve activity by the arterial baroreceptors in Wistar rats with cirrhosis induced by bile duct ligation (BDL), experiments were performed four weeks after BDL. Mean arterial pressure (MAP), heart rate (HR), rSNA and sSNA were recorded under anesthesia. The baroreflex sensitivity (BS) was assessed by the reflex changes of rSNA and sSNA induced by alterations in MAP in response to vasoactive drugs. Renal and hepatic noradrenaline was assessed by HPLC. Cirrhotic rats (CR, n=6) showed decreased MAP (control (CO, n=6):108±2 and CR:95±2mmHg) and increased HR (CO:352±10 and CR:396±13bpm). In CR group, significant increase in the basal sSNA (CO:36±8 and CR:115±13pps) accompanied by increased hepatic noradrenaline level (CO:0.7±0.1 and CR:1.4±0.1ng/mL), besides increase in the BS for PHE (CO: −0.47±0.1 and CR: −1.75±0.3) and for SNP (CO: −0.34±0.1 and CR: −1.01±0.2). However, in CR group a significant decrease in rSNA (CO:92±7 and CR:57±5pps) accompanied by no changes in rSNA BS or renal noradrenaline level (0.14±0.1ng/mL). The present study shows that in the initial phase of cirrhosis a preferential increase in sSNA appears independently of arterial baroreceptor dysfunction.Financial support: CAPES and CNPq.
Molecular inhibition of endoplasmic reticulum (ER) stress targeted to the subfornical organ (SFO) prevents slow‐pressor angiotensin‐II (Ang‐II) mediated hypertension
Authors: Young Colin N. , Guruju Mallikarjuna , Butler Scott D. , Davisson Robin L. 
Published: June 2021

We have shown that ICV administration of the chemical ER stress inhibitor TUDCA ameliorates slow‐pressor Ang‐II hypertension (HTN); however the precise brain nuclei involved are unknown. Since the SFO is critical in this model of HTN, we tested the hypothesis that ER stress in SFO is causally linked to Ang‐II HTN. A new adenovirus encoding the ER chaperone GRP78 was constructed (AdGRP78) in order to inhibit ER stress site‐selectively in the SFO. In vitro studies in Neuro2A cells confirmed AdGRP78 was targeted to ER and inhibited Ang‐II‐induced ER stress biomarker induction. In vivo targeting of AdGRP78 to SFO of C57 mice caused robust SFO‐selective expression of the GRP78 transgene and inhibition of the ER stress biomarker CHOP in this region following ICV injection of the chemical ER stress inducer thapsigargin (1ug; AdLacZ 1.6 ± 0.1 vs AdGRP78 1.1 ± 0.1, p<0.05). To test if AdGRP78‐mediated inhibition of ER stress in SFO prevents slow‐pressor Ang‐II HTN, mice underwent SFO‐targeted injection of AdGRP78 or AdLacZ and were instrumented with radiotelemeters (DSI) for mean arterial blood pressure (MAP) recordings. After recovery, osmominipumps were implanted for 2 wk slow‐pressor Ang‐II infusion. AdGRP78 prevented the development of slow‐pressor Ang‐II HTN (day 14 MAP: AdLacZ 138 ± 3 vs AdGRP78 106 ± 3 mmHg, p<0.05, n=4–6). These data implicate ER stress in the SFO as a key mediator of slow‐pressor Ang‐II HTN.HL063887
Immunohistochemical expression and nitration of MnSOD in the adrenal gland and the carotid body of rats exposed to chronic intermittent hypoxia
Authors: Moya Esteban , Arias Paulina , Iturriaga Rodrigo 
Published: June 2021

Oxidative stress is associated with the hypertension induced by chronic intermittent hypoxia (CIH), but the mechanisms involved in the increased ROS levels are not entirely known. Since, ROS levels are regulated by antioxidant enzymes, such as MnSOD, it is likely that a reduction in MnSOD levels or on its enzymatic activity produced by nitration of tyrosine residues may contribute to the oxidative stress. Thus, we studied the effects of CIH on the immunoreactive levels of MnSOD and 3‐nitrotyrosine (3‐NT), and the nitration of MnSOD in the carotid body and adrenal glands. Sprague‐Dawley male rats were exposed to CIH (5% O2, 12 times/hr for 8 hr/day) for 7 days. Tissues extracted from anesthetized rats, were fixed, included in paraffin, cut and processed for immunohistochemical detection of MnSOD and 3‐NT. In addition, tissues were processed for immunoblot measurements of MnSOD levels and nitration. CIH increased the MnSOD levels in the carotid body and adrenal glands, but also increased the nitration of MnSOD. Thus, our results suggest that despite of the increased MnSOD levels, CIH may also reduce the activity of the enzyme due to the formation of 3‐NT. Therefore, this novel post‐transductional modification of MnSOD induced by CIH may contribute to the oxidative stress.Supported by FONDECYT 1100405 & AT 24110172
Effect of neonatally induced brain serotonin depletion on anxiety‐like behavior of adult offspring wistar rats
Authors: Silveira Anderson Luiz Bezerra , Laureano-Melo Roberto , Fonseca Fabricia Viana , Lustrino Danilo , Mencalha Rodrigo , Reis Luis Carlos , Côrtes Wellington Silva 
Published: June 2021

Serotonin (5‐HT) plays an important role in the central nervous system embryogenesis of mammals. Indeed, the serotonergic neurons are the earliest to be generated and can modulate neuronal plasticity. Some studies showed that brain 5‐HT depletion in the neonatal period leads to a plastic cytoarchitectonic change of the serotonergic system, which influences several brain systems ontogeny. Therefore, we investigated the effect of systemic pCPA (p‐chloro‐phenylalanine) injection (100mg/kg, sc), from the 8th at 16th post‐natal day, on the behavioral response of adults female and male rats. For this purpose, we use the forced swimming, open field and elevated plus maze tests. Male rats programmed with pCPA had longer time spent in open arms in plus maze test and lower immobility time in forced swimming test than the controls (148.8±8.8 vs. 99.7±21.4s and 109.0±7.8 vs. 158.1±18.2s, respectively). Programmed female rats had higher number of quadrants traversed in open field test, longer time spent in open arms in plus maze and lower immobility time in forced swimming tests than the control females (137.7±8.5 vs. 101.8±3.8; 140.7±3.1 vs.78.0±7.9s and 85.3±13.1 vs. 168.0±3.4s, respectively). These findings suggest that programming with pCPA alters neural circuits involved with anxiety‐like behavior in adult rats. In addition, we conjecture that the decrease in brain levels of 5‐HT during development may have led to a higher expression of 5HT1A receptors, especially in female rats.Support: FAPERJ & CNPq
Lack of N‐Sulfation of Podocyte Cell Surface Heparan Sulfate Glycosaminoglycans Leads to Abnormalities in Podocyte Organization, Adhesion, and Migration
Authors: Sugar Terrel A , McCarthy Deborah J. , Esko Jeffrey D. , Holzman Lawrence B. , McCarthy Kevin J. 
Published: June 2021

Previous work showed that cell surface heparan sulfate (HS) glycosaminoglycans (GAG) modulate podocyte (podo) organization on the glomerular basement membrane (Kid. Int. 74: 289–299). This study examined the role of HSGAG sulfation in this process by podo‐specific deletion of NDST1, the enzyme responsible for N‐sulfation of HSGAG. A novel mutant mouse (2.5P‐Cre/NDST1fl/fl) and immortalized podo line (NDST1‐null) were developed using a Cre‐lox approach. The kidneys in mutant mice appeared normal compared to controls, the only measurable difference in routine LM studies was a slight glomerular hypertrophy in the mutant mice. Electron micrographs from mutant animals showed mild podo foot process effacement and abnormal podo attachment to Bowman's capsule, suggesting that podo‐matrix interactions were affected. NDST1‐null podo had a significantly decreased ability to adhere, spread, and migrate upon fibronectin compared to controls. Mutant podo also failed to assemble focal adhesions as efficiently as control cells. These results indicate that HSGAG sulfation is a critical mediator of cell surface proteoglycan (PG)‐matrix interaction, highlighting the importance of HSPGs in orchestrating podo cell behavior.This work is supported by: NIDDK RO1‐DK077860Grant Funding Source: NDDK RO1‐DK077860
MMP expression by intervertebral disc cells is responsive to changes in extracellular osmolarity
Authors: Cui Ying , Lee Sheena , Yu Jing , Urban Jill 
Published: June 2021

We examined the response of cells from the central regions of the intervertebral disc, the nucleus pulposus (NP) to changes in extracellular osmolarity with particular reference to matrix metalloproteinases (MMPs) expression.NP cells were extracted from adult bovine caudal discs by enzyme digestion and cultured in alginate beads to maintain phenotype. MMP production was investigated by zymography and Western blotting, and total RNA was extracted from the cells and gene expression analysed using the Affymetrix GeneChip Bovine Genome Array.MMP‐2, MMP‐3 and MMP‐13 were significantly upregulated when cells were cultured in hypo‐osmotic medium i.e. 260 mOsm seen in severely degenerate discs compared to 356 and 489 mOsm seen in healthy discs. A similar upregulation was seen at the gene level.Our results show that expression of MMPs by disc cells is regulated by extracellular osmolarity, with MMP expression rising as osmolarity falls. These results could explain in part the findings that MMP expression increases with degree of disc degeneration i.e. with loss of aggrecan and fall in extracellular osmolarity.Grant Funding Source : AAA
Sex Differences and Variation in Lower Limb Element Lengths: Implications for Physical Therapeutic Treatment of Anisomelia
Authors: Weir Alicia Suzanne , Márquez Samuel 
Published: June 2021

Lower limb length discrepancy (LLLD) is a common condition affecting large portions of the general population and has been related to many biomechanical abnormalities in posture, pathological stress on joints, and modification of locomotor gait. Structural limb length discrepancy involves asymmetry in relative lengths of individual lower limb elements. Our study aimed to eliminate the error associated with using surface anatomical landmarks to measure limb length by instead examining the actual bony anatomy of the lower limb via disarticulated lower limbs from donor bodies at the SUNY Downstate School of Medicine. Limb length was calculated as the combined lengths of the femur & tibia. A total of 41 specimens were used (15 males & 26 females). Results showed that there were no significant (p<0.05) sexual differences in femur or tibia asymmetry. Femur length exhibited greater relative asymmetry than tibia length but this difference was not significant (p<0.05). The mean difference between left and right femur length was 48.37 millimeters (mm) while left and right mean tibia length differed by 49.6 mm. Total left limb length was, on average, longer than on the right by 1.78 mm. LLLD patients may require rehabilitative therapeutic protocols that are patient‐specific rather than general since this condition may be attributed to differences in overall limb length rather than femur or tibia length alone.Grant Funding Source: Alumni Association of SUNY Downstate College of Medicine
The role of Brahma‐related gene 1 in regulating the expression of microRNAs in colonic smooth muscle cells
Authors: Chen Meng , Herring Paul 
Published: June 2021

To identify microRNAs (miRs) that are regulated by Brahmarelated gene 1 (Brg1) in smooth muscle cells (SMCs), we performed microRNA array screens of colonic smooth muscle. Quantitative reverse transcription‐polymerase chain reaction assays confirmed that 6 miRs were down‐regulated and 6 up‐regulated in smooth muscle specific Brg1 knockout tissue. Inactivation of endogenous Brg1 by introducing dominant negative Brg1 into wild type SMCs in vitro, revealed that miR‐143/145 are likely to be directly regulated by Brg1 in smooth muscle cells. miR‐143/145 have been previously shown to be regulated by myocardin and to be important for regulating the phenotype of smooth muscle cells. In Brg1 null SW13 cells, miR‐143/145 were dramatically induced by myocardin only in the presence of Brg1. Chromatin immunoprecipitation assays demonstrated that myocardin increased the binding of serum response factor to the miR‐143/145 promoter only in the presence of Brg1. Together these data suggest a mechanism in which Brg1 containing SWI/SNF complexes are required for myocardin to induce expression of miR‐143/145 in smooth muscle. This suggests that SWI/SNF mediated chromatin remodeling regulates the phenotype of smooth muscle not only by directly affecting expression of smooth muscle specific genes, but also by regulating expression of microRNAs that further modulate expression of their targets.Supported by NIH DK61130.
NIP45 Promotes Telomere Targeting to PML Bodies in ALT Cells
Authors: Farley Demetra D , Yu Hongtao 
Published: June 2021

Telomere length maintenance is critical for continued cell proliferation. Certain cancer cells do not have active telomerase and use homologous recombination to lengthen their telomeres, a mechanism referred to as alternative lengthening of telomeres (ALT). We have previously shown that the SMC5/6 complex is required for telomere length maintenance in ALT cells. The SMC5/6 component MMS21 sumoylates multiple telomere‐binding proteins and promotes telomere targeting to ALT‐associated PML bodies (APBs). In this study, we show that the SUMO‐like protein NIP45 is also required for targeting telomeres to APBs. NIP45 itself localizes to PML bodies and promotes MMS21‐dependent sumoylation of telomere‐binding proteins. The C‐terminal SUMO‐like domain of NIP45 is sufficient to restore both APB formation and sumoylation of telomere‐binding proteins in NIP45 RNAi cells. Our results suggest that NIP45 enables PML‐body recruitment and sumoylation of telomere‐binding proteins, thus promoting APB formation in ALT cells.This work was supported by a National Research Service Award grant 5 T32 GM 8203‐24 to Demetra D. Farley.
Determining the effect of dithiolethione compounds on the activity of human glyceraldehyde‐3‐phosphate dehydrogenase
Authors: Chavis John Taylor , Neal Jacob , Switzer Christopher , Wink David A. , Garcin Elsa 
Published: June 2021

Dithiolethione compounds have chemopreventive, cytoprotective, and antimitogenic effects. We have shown that some of these compounds interact with glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH). In cells, GAPDH is an abundant and multifaceted protein involved in glycolysis, cell death, DNA repair, regulation of gene expression, tRNA export, membrane fusion and transport. As a result of its plethora of roles, there is an incentive in understanding how dithiolethiones affect GAPDH activity and function. Dithiolethiones can directly or indirectly modify cysteine residues in protein targets. GAPDH contains three cysteine residues that are susceptible to thiol‐modifying agents. Therefore, we set out to examine how the dithiolethione, ADT‐OH, affects GAPDH activity.Human GAPDH was overexpressed in bacterial cells and purified by ion‐exchange and affinity chromatography. We measured the catalytic activity of GAPDH in the absence and the presence of ADT‐OH, and in the absence of DTT. Comparison of the kinetics parameters for unmodified GAPDH and GAPDH modified with increasing concentrations of ADT‐OH reveals a concentration‐dependent decrease of GAPDH catalytic activity.Our next step will be to determine the exact mechanism of ADT‐OH modification of GAPDH by combining site‐directed mutagenesis, mass‐spectrometry, circular dichroism, and x‐ray crystallography.FundingUMBC DRIF SRAIS (EG)This research was supported in part by a grant to UMBC from the Howard Hughes Medical Institute through the Precollege and Undergraduate Science Education Program.
Effects Of Orange Juice And Vitamin C On The Expression Of Some Selected Genes ( Tnfr, Sod3, P53, Pgr ) In Sprague‐Dawley Rat Brain
Authors: Ebuehi Osaretin Albert , James Ayorinde , Salami Yusuf , Mgbeadichie Imelda 
Published: June 2021

The comparative effects of Vitamin C and Nigerian local orange juice on the gene expression levels of Superoxide dismutase (Sod), Tumour necrosis Factor Receptor (Tnfr), p53 protein, and progesterone receptor (Pgr) genes were evaluated in rat neuronal tissues.5ml/kg bodyweight of extracted orange juice and 20mg/kg bodyweight Vit C were administered orally to Sprague Dawley rats, which were divided into control, Vit. C and orange groups. After the 7th day of administration, total RNA was extracted from the rat brains and normalized RNA was converted to cDNA. PCR Primer pairs were designed using Primer 3 and NCBI primer blast tool. Sybr green Real time PCR relative quantification was done.Orange juice extract contains 15.84 mg Vit C, 13.67g total sugar, 0.02 mg Sodium, 0.15 mg Iron, 11.48 mg Magnesium, 44.20 mg Calcium, 4.76 mg Potassium, 0.75 mg Zinc, and 22.9 mg Phosphorus. Relative quantification gene expression assays in the rats show a 400 fold change in Tnfr and 38 fold change in p53 gene in the orange administered group in comparison to the Vit C administered and control groups. Vit C caused a 420 fold change in the expression of Pgr gene in comparison with the orange administered group. Data show that orange juice administered at 5ml/kg body weight show higher levels of gene expressions of Tnfr and p53 genes, thereby indicating brain tumour preventing ability of oranges.
Vitamin C regulates iron uptake from transferrin – a novel role for ascorbate in iron metabolism?
Authors: Richardson Des R , Chikhani Sherin , Richardson Vera , Lane Darius J.R. 
Published: June 2021

We previously demonstrated that ascorbate enhances cellular iron (Fe) uptake from 55Fe‐citrate by transmembrane ascorbate cycling. Here we have examined ascorbate's effect on cellular Fe uptake from the major serum Fe transport protein, transferrin (Tf). Incubation of SK‐Mel‐28 cells with ascorbate (50 μM) resulted in a significant 1.5–2.5‐fold increase in 59Fe uptake from 59Fe2‐Tf. Ascorbate oxidase inhibited ascorbate‐stimulated 59Fe uptake from 59Fe‐citrate, but was ineffective against ascorbate‐stimulated 59Fe uptake from 59Fe2‐Tf. The amount of cellular 125I‐Tf uptake, and the rate of 125I‐Tf cycling, was unaffected by ascorbate. Co‐incubation of cells with ascorbate and Fe2‐Tf also enhanced ferritin expression, ferritin 59Fe incorporation. Heterologous expression studies indicated that TfRs 1/2 are necessary for ascorbate's stimulatory effect. Ascorbate‐stimulated, but not basal, 59Fe uptake from 59Fe2‐Tf was inhibited by the membrane‐permeant thiol donor, N‐acetyl‐l‐cysteine and the antioxidant, ebselen. Moreover, ascorbate/Fe2‐Tf markedly decreased intracellular NADPH, but not total NADP levels and increased intracellular reactive oxygen species production. These data suggest that ascorbate may stimulate Fe uptake from Fe2‐Tf through a pro‐oxidant mechanism of action. Ascorbate's contribution to cellular Fe uptake and metabolism may be more complex than initially realized.Support: National Health and Medical Research Council (NHMRC) of Australia and Cancer Institute New South Wales.
Prediction of The Risk for Hypertension Among Carrier of C825T Genetic Polymorphism of G Protein Beta 3 Gene (GNB3)
Authors: Hemimi Neveen Salah El Din , salam Mona Mohamed Abd El , Ahmad Deena Jalal 
Published: June 2021

BackgroundGNB3 825T is associated with the occurrence of the splice variant Gß3s, which, despite a deletion of 41 amino acids, is functionally active in reconstituted systems. This may cause enhanced vascular reactivity and increased proliferation of smooth muscle cells and cardiac myocytes, ultimately resulting in vascular and myocardial hypertrophy.AimTo predict the risk for hypertension in individuals with C825T genetic polymorphism of G protein β3 gene.Material and MethodThe study consisted of 192 normotensive individuals and 120 hypertensive patients. Individuals were genotyped for C825T genetic polymorphism of G protein β3 gene by using polymerase chain reaction‐ restriction fragment length polymorphism. Statistical analysis was done by SPSS program.ResultsFrequency of C and T alleles were 47.5% and 52.5% in hypertensive group compared to 62% and 38% in control group. The carriers of T allele exhibited a significant greater risk for hypertension compared to carriers of C allele (OR= 1.8, 95%CI= 1.3–2.6).ConclusionT allele is a risk factor for hypertension.Source of Fund: DMCG
Biochemical requirements for suppressing a constitutively active allele of Gs alpha
Authors: Tobar-Rubin Raquel , Sultan Dahlia , Janevska Daniela , Rylaarsdam Robin Pals 
Published: June 2021

Inappropriate activation of the Gs alpha subunit by mutation of modification of Arg201 is associated with the human diseases of McCune‐Albright Syndrome and cholera. Previous work in our laboratory identified Asp223 as a site where substitution to valine could reverse the constitutive activity of an Arg201His mutation. In this study, Asp223 was substituted with a variety of other amino acids, including glutamic acid, asparagine, glutamine, alanine, leucine, and glycine. HEK cells transfected with plasmids carrying the different Gs alpha subunit alleles were used to measure basal levels of cAMP. The Arg201His allele significantly elevates basal cAMP. Substitution of Asp223 with nonpolar residues suppressed the elevation in basal cAMP, while substitution with acidic or polar residues had no effect on the constitutive activity of the Arg201His mutation. This characterization of which amino acids at residue 223 can suppress the Arg201His mutation may provide a foundation for identifying small molecules that can be used as effective therapies against McCune‐Albirght Syndrome.Supported by NIH grant1R15DE02109‐01
Define a novel role for Giα proteins in differentially regulating RTK‐mediated signaling in response to growth factors
Authors: Chu Wen-Ming , Wang Zhanwei , Cruz Rica Dela , Chu Catherine H , Jiang Meisheng 
Published: June 2021

The activation of the ERK and the PI3K/Akt/mTORC1 pathways by growth factors is mediated by the receptor tyrosine kinases (RTKs), and plays a crucial role in physiological and pathological processes. However, the molecular mechanism of this activation is still unclear. Herein we demonstrated that Giα proteins differentially regulate RTKs‐mediated activation of the ERK and the Akt/mTORC1 pathways.Loss of Giα proteins impaired activation of ERK by EGF, IGFI and Insulin, but not bFGF. Intriguingly, while Akt and mTORC1 activation by EGF and bFGF was severely defective in Giα‐deficient cells, this activation by insulin and IGFI was only slightly reduced. Further, Giα proteins altered Akt, mTORC1 and ERK activation by serum and PDGF. Also, growth factors induced the association of Giα with RTKs and their downstream adaptors. Loss of Giα proteins impaired RTKs’ association with their adaptors indicating that Giα proteins act downstream of RTKs but upstream of the adaptors.Finally, we found that knockdown of Giα proteins in human cancer cell lines diminished Akt, mTORC1 and ERK activation by growth factors leading to a defect in cancer cell growth and migration. Given the fact that growth factors and their receptor pathways play pivotal roles in tumorigenesis and metastasis of cancer, our findings will promote further understanding of RTK signaling regulation in cancer and may have implications for cancer therapy.