bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanoregulated expression of smooth muscle alpha‐actin in myofibroblasts is mediated by actin dynamics and myocardin related transcription factor‐A localization
Authors: Broiles JoSette LB , Hinz Boris , Wipff Pierre‐Jean , Howard Eric W , Haaksma Carol J , Tomasek James J 
Published: June 2021

Myofibroblasts are specialized fibroblasts that facilitate wound closure through expression of smooth muscle (SM) contractile proteins and generation of contractile force on the surrounding matrix. We hypothesize mechanoregulation of SM α‐actin (SMAA) expression in myofibroblasts is mediated by actin dynamics regulating localization of myocardin related transcription factor‐A (MRTF‐A); on compliant substrata, high levels of G‐actin will sequester MRTF‐A, while on stiff substrata decreased G‐actin levels will release MRTF‐A to interact with the SMAA promoter. Rat embryonic fibroblasts cultured on novel deformable substrata of varying stiffness were analyzed. Increasing substratum stiffness resulted in a graded increase in SMAA promoter activity and endogenous mRNA expression, focal adhesion and stress fiber assembly, and MRTF‐A nuclear localization, suggesting that the lack of a critical stiffness acts as a switch. The actin polymerizing agents, jasplakinolide and cytochalasin D, promoted nuclear localization of MRTF‐A and increased SMAA expression, independent of substratum stiffness. Similarly, a constitutively nuclear MRTF‐A promoted SMAA expression independent of substratum stiffness. This work demonstrates that actin dynamics, in response to the mechanical environment, regulate nuclear localization of MRTF‐A and thereby expression of SMAA. Funded by NIH grant R01 GM60651.Grant Funding SourceNIH grant R01 GM60651
The role of heme oxygenase in wound healing
Authors: Nicholson Susannah E , Johnson Fruzsina K , Stewart Ronald M , Johnson Robert A 
Published: June 2021

Damaged tissues express heat shock proteins. One such protein, heme oxygenase (HO‐1), catalyzes conversion of heme to liberate iron, biliverdin and carbon monoxide (CO). Evidence suggests that heme and the HO products iron, biliverdin and CO may adversely impact tissue growth. Accordingly, we wanted to determine the effects of HO activity on wound healing in rats. Rats were treated with 20 µmol/kg IP daily of heme‐L‐lysinate, iron or biliverdin and received full thickness abdominal incisions, which were then sutured. Controls received a laparotomy only. An additional group received matched administration of exogenous CO. To evaluate HO activity, whole animal CO excretion was measured using solid‐phase gas chromatography. The thickness of the wound tissue and the tearing force were measured 14 days after the incisions. Tensile strength and the normalized breaking strength were calculated to evaluate wound strength. CO excretion was increased by 60% in animals treated with heme as compared to controls. Normalized breaking strength was decreased by heme, iron, and biliverdin, but tensile strength was unchanged. The effects can be attributed to a decrease in tissue thickness. In contrast, CO increased both normalized breaking strength and tensile strength but did not change the tissue thickness. These findings suggest that the release of iron and biliverdin during heme degradation may adversely impact tissue growth whereas the release of CO may help to stabilize against the effects of the other HO products.Supported by NIH/DOD grant HL64577.
HYPOXIA PROMOTES WOUND HEALING THROUGH SELECTIVE REGULATION OF INTEGRIN β1 BY HYPOXIA‐INDUCIBLE FACTOR (HIF)
Authors: Keely Simon , Glover Louise E , MacManus Christopher F , Campbell Eric L , Furuta Glenn T , Colgan Sean P 
Published: June 2021

Due to localized vascular damage and increased oxygen demand, wound healing occurs in a relatively hypoxic setting. This is particularly relevant to wound healing in chronic inflammatory conditions such as Crohn's disease and ulcerative colitis. Here, we sought to identify the role of hypoxia (Hx) in mechanisms of wound repair in a model of the intestinal submucosa. Initial studies revealed that Hx promotes wound healing, as modeled by an increase in intestinal fibroblast‐mediated collagen gel contraction. Guided by results from transcriptional profiling, we identified the selective induction of fibroblast integrin β1 (ITGB1) by Hx. Further analysis revealed that both Hx and pharmacological activators of hypoxia‐inducible factor (HIF), induce fibroblast β1 integrin mRNA, protein and function by as much as 4‐fold. Cloning of the β1 integrin gene promoter revealed a 10±0.8‐fold increase in promoter activity in response to Hx. Subsequent studies identified functional DNA binding to HIF in the ITGB1 gene. Mutational analysis of the HIF binding site within the ITGB1 promoter resulted in a loss of ITGB1 hypoxia‐inducibility. In vivo murine studies revealed a correlation between colitic disease severity and tissue ITGB1 expression (R2 = 0.80). Combined, these results demonstrate that Hx induces fibroblast ITGB1 expression and function by transcriptional mechanisms dependent on HIF.Grant Funding SourceNIH
Development of S100B knockout embryos following inhibition of S100A1 protein expression
Authors: Chan Wood Yee , Cheung Siu Yuen , Heizmann Claus W. 
Published: June 2021

S100A1 and S100B, members of the EF‐hand family of Ca2+‐binding proteins, exist in cells as homo‐ or hetero‐dimers. Our studies on mouse embryos showed that these two proteins shared some common expression sites including skeletal tissues, dorsal root ganglia, trigeminal ganglia and the hindbrain. However, neither S100A1 nor S100B knockout mice exhibit overt structural abnormalities. In the present study, we had examined the development of mouse embryos in which expression of both proteins was inhibited. Small interfering RNAs targeting specific sequences of S100A1 mRNA were microinjected into S100B knockout embryos in utero at E13.5 when S100A1 protein had just started its expression. Two days after microinjection, S100A1 expression was examined by reverse transcription‐PCR and immunohistochemical localization and structural changes determined after serial sectioning. A decrease of S100A1 expression and absence of S100B protein were observed, but no morphological anomalies were found in S100B knockout embryos with a reduction of S100A1 expression. Our observations support the notion that both S100A1 and S100B proteins are not indispensible for embryonic development.The work was supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (Project no. CUHK4421/05M) and a Direct Grant from the Faculty of Medicine, CUHK (Project Ref 2007.1.006, ID 2041322).
Lmx1b Modulates Extracellular Matrix Expression During Limb Dorsalization
Authors: Feenstra Jennifer Marie , Kanaya Kohei , Pira Charmaine U , Oberg Kerby C 
Published: June 2021

.Lmx1b is a homeodomain transcription factor that is known to regulate dorsal limb identity and Lmx1b knockout (KO) mice develop nearly symmetrical ventral‐ventral limbs. Currently, downstream limb‐specific targets of Lmx1b are poorly defined.To identify and characterize potential limb‐specific genes targeted by Lmx1b, we compared gene arrays from Lmx1b KO and wild type (WT) mouse limbs harvested during limb outgrowth and patterning, i.e., 11.5, 12.5, and 13.5 days post coitum (dpc). Gene expression was analyzed using replicate Affymetrix 430 2.0 mouse genome arrays. Real‐time PCR confirmed microarray results and whole mount in situ hybridization localized gene expression.Genes that were differentially expressed throughout this period of limb development included 46 significantly up‐regulated and 10 down‐regulated genes. Lmx1b up‐regulated several genes linked to tendon and bone formation including: Emx2 (a homeodomain transcription factor), several extracellular matrix (ECM) proteoglycans (Kera, Lum, Acan) and two Matrilins (Matn1, Matn4). Real‐time PCR confirmed differential expression and whole mount in situ hybridization localized expression to the dorsal tendon primordia.These data suggest that Emx2 and a unique collection of ECM‐associated factors orchestrate Lmx1b‐regulated dorsalization by altering the environment in which tendon formation and/or attachment occur.Grant Funding SourceNICHD ‐ HD39421
Rescuing craniofacial development in an avian model of holoprosencephaly
Authors: Chong H. Jonathan , Marcucio Ralph 
Published: June 2021

Blockade of Sonic hedgehog (Shh) signaling in the embryonic forebrain leads to altered gene expression in the facial ectoderm and morphologic changes resembling holoprosencephaly. However, the molecular pathways that are involved in communications between the forebrain and facial ectoderm are not known. The aim of this study was to test the ability of candidate pathways to restore ectodermal gene expression and craniofacial morphology following blockade of forebrain Shh signaling. Activation of the Bone Morphogenetic Protein‐2 (BMP‐2) pathway in the head mesenchyme of treated embryos did not rescue morphology and created severe phenotypes. In contrast, preliminary results suggest that activation of the Shh pathway leads to partial morphologic rescue. Ongoing studies are examining changes in gene expression patterns in the ectoderm covering the upper jaw anlagen. These data suggest that exogenous Shh signaling, but not BMP‐2 signaling, restores forebrain‐ectodermal communications and will help elucidate the normal signaling mechanisms between these tissues.Grant Funding SourceNIH/NIDCR R01DE018234 to R.M. and HHMI Medical Research Training Fellowship to H.J.C.
Humanities in gross anatomy project: a humanistic learning tool
Authors: Canby Craig A. , Bush Traci 
Published: June 2021

Gross anatomy affords physical therapy students an opportunity to discover human morphology through intimacy with the dead. Moreover, it also socializes future physical therapists to the humanistic aspects of the profession. In 2007, faculty decided to socialize students to the humanities with a new course requirement: Humanities in Gross Anatomy Project (HuGA) Project. At the end of the course, students submitted a project that described how the student had been personally touched by the donor's gift and how the gift contributed to their professional growth and education. The submission could be a narrative, poem, song, video, etc. All students performed admirably; thus taking the first step in socializing themselves to their professional education. The overall success of the HuGA Project may be exemplified by these excerpts from a submitted poem as a tribute to a great teacher ‐ the donor:"But this lifeless body, told stories to usThrough arteries, veins, and the things that we touchedShe taught me respect, and I learned what it meansTo work with integrity, to work professionallyHer gift truly selfless, her choice such a gift"Providing students with humanistic learning opportunities early within the curriculum, facilitated reflective learning. The utilization of reflection as it relates to clinical decision making and client interaction is critical for physical therapy practice.
How anatomy is taught to dental students: Results of an ADEA survey to US and Canadian faculty
Authors: Lambert H. Wayne , Atsas Stavros , Gould Douglas J. , Hutchins Robert J , Burk Dorothy T 
Published: June 2021

Members of the Anatomical Sciences Section of the American Dental Education Association (ADEA) recently completed an international survey of the directors of all North American dental gross anatomy courses to assess: 1) what level of detail are specific topics and content areas being presented; 2) when in the curriculum are specific content areas are taught; 3) what areas are omitted; and 4) what other areas are of concern with regard to North American dental gross anatomists. The survey received a 95.5% response rate representing 64 (of 67) of the US and Canadian dental schools. The results of this survey indicate, amongst other things that: 1) the use of computer‐assisted instruction (CAI) tools has increased; 2) emphasis on clinical topics has increased; 3) reliance upon medical school faculty and facilities is high; 4) a pattern of increased use of integrated curricula among dental schools has emerged; and 5) a general trend for a decrease in student contact hours is ongoing. The specific data are currently being analyzed and will be presented. These data will provide the framework by which course directors and administrators, in need of curricular information, can make more informed decisions in the appropriateness of content and even provide guidance in evaluation of their program.Grant Funding SourceAAA Young Faculty Travel Award – Supported by AAA Second Century Fund
The Impact of Wearing Scrubs on Contextual Anatomy Learning
Authors: Finn Gabrielle Maria 
Published: June 2021

The impact of contextual learning in anatomy is of interest, as students often learn in one setting (medical school) and apply this in another (practice). Learning in an educational context may not transfer well to practice (clinical) environments.We explored the impact of an authentic aspect of context (wearing scrubs) on learning and recall, using a cross‐over design.82 1st year medical students participated.Students completed a gross anatomy and kidney imaging pre‐test in their own clothes, to establish if they had prior knowledge.Students, divided into groups, wore either scrubs or their own clothes for the teaching session on the gross anatomy of the kidney. A gross anatomy specific mid‐test was then completed immediately after the teaching session.Next students changed into the opposite clothing and attended a self‐directed kidney imaging session. An imaging specific mid‐test was then completed. 4 weeks after teaching students completed 2 post‐tests in their own clothes, a gross anatomy and an imaging test.Data analysis was performed using a paired t‐test, p<0.05 was considered statistically significant. Results show a significant difference between groups; p=0.04. The intervention's effect size was calculated as 0.27, a 'moderate' effect in teaching terms. Students examined in the same context as they were taught in recalled significantly more information.Research supported internally.Grant Funding SourceDurham University
A computer‐assisted instructional tool for gross neuroanatomy
Authors: Lynn Lorinda Kay , Foreman K. Bo 
Published: June 2021

Unstained serial brain sections are a major teaching resource in the gross neuroanatomy laboratory. However, outside of the teaching laboratory, students typically rely on atlases that feature stained sections, drawings and clinical scans. To provide students with the most relevant study materials outside of lab, we developed a computer assisted instructional (CAI) tool featuring unstained brain dissections and serial sections. Our objective was to determine if this CAI tool is a beneficial adjunct to neuroanatomy lab. Embalmed human brains were dissected or frozen and sectioned. The prepared brains were photographed, labeled using Macromedia Fireworks, and inserted in a web application developed using Macromedia Flash. Sixty‐nine physical and occupational therapy students had access to this tool while enrolled in a neuroanatomy course. Students were given a questionnaire and the data were analyzed using descriptive statistics. On a scale of 1 (strongly disagree) to 10 (strongly agree), students rated the CAI tool as beneficial to learning (mean 9.1±0.7), said it provided education on structure identification (mean 8.3±1.5), found it easy to navigate (mean 9.0±1.0), and preferred it to similar pictures in atlases (mean 8.0±1.5). We conclude that this CAI tool is a beneficial adjunct to neuroanatomy lab. The information gained from this study will be used to guide further development of this tool.Grant Funding SourceN/A
Creating online Histology study tools for Medical/Dental students at the University of British Columbia (UBC)
Authors: Korj Oxana , Lin Cheng , Pinder Karen , Ovalle William K. , Walters Rebecca , Yule Heather 
Published: June 2021

Histology is a core preclinical program at UBC Medical and Dental School. In conjunction with lectures and laboratories, a significant portion of student learning is through online resources such as weekly practice quizzes. We aimed to create new quizzes in Term Two of the first year Histology curriculum.In order to makequizzes more representative of questions encountered in summative assessments and in clinical situations, we animated virtual slides to simulate microscopic viewing. The movable virtual slides were created by compiling snapshots of tissue sections at increasing magnifications into a "gif" file using Adobe Photoshop. To producean online version of the quiz, questions were formatted using Respondus® software and uploaded to WebCT.WebCT allows easy access to online quizzes and instant feedback for students. In May 2009, we will survey the Medical/Dental Class of 2011 and compare student satisfaction with quizzes from Term One and Term Two. This project was supported by Summer Studentships from the Department of Cellular and Physiological Sciences at UBC.Grant Funding SourceAAA
Multiple functions of the Drosophila Orc6 protein
Authors: Chesnokov Igor , Balasov Maxim , Huijbregts Richard , Svitin Anton 
Published: June 2021

The Origin recognition complex (ORC) is important for the DNA replication in eukaryotic cells. ORC is also involved in other cell functions. The smallest Drosophila ORC subunit, Orc6, consists of two functional domains. Larger N‐terminal domain directly involved in DNA binding and is important for ORC‐dependent DNA replication. Smaller C‐terminal domain is important for cytokinesis.Deletion of Orc6 gene was created in Drosophila. Mutant lethal alleles of Orc6 are defective in both DNA replication and cell proliferation during larval stages of development. Homozygous Orc6 mutants display disc‐less phenotype and show abnormal chromosome condensation and segregation. Mutant cells arrest in both G1 and mitosis stages of the cell cycle. Orc6 mutation can be rescued to viability by full‐length Orc6 transgene. The expression of a transgene carrying the core replicative N‐terminal domain of the Orc6 protein results a restoration of DNA replication in mutant larval tissues. The mutant cells carrying this transgene do not exhibit G1 arrest but nevertheless accumulate at mitosis.The cytokinetic function of DmOrc6 is associated with the C‐terminal domain of the protein. Orc6 interacts with the septin protein Pnut, which together with the septins Sep1 and Sep2 forms a septin complex important for cytokinesis. Septin complexes exhibit GTPase activity and can assemble into large filaments. The interaction of Orc6 with the septin complex is dependent on the coiled‐coil domain of Pnut. Furthermore, the binding of Orc6 to Pnut increases the intrinsic GTPase activity of the Drosophila septin complex, while in the absence of GTP it enhances septin complex filament formation.Together our results suggest an active role for Orc6 in DNA replication and septin complex function. Orc6 might be a part of a control mechanism directing the cytokinesis machinery during the final steps of mitosis.
Functional Analysis of the MacroH2A Histone Variant During Zebrafish (Danio rerio) Development
Authors: Guajardo Laura ines , Muñoz Valentina , Bouvet Philippe , Molina Alfredo , Alvarez Marco 
Published: June 2021

In the nucleus, DNA is associated to different proteins, forming a highly dynamic nucleoprotein complex termed chromatin. Assembly of DNA into nucleosomes causes a massive repression of transcription, which can be reversed by different epigenetic mechanisms, such as post‐translational modification of histones and incorporation of histone variants. The variant of the canonical histone H2A, macroH2A (mH2A), possesses a large non‐DNA binding C‐terminal domain termed "non‐histone region" (NHR), which is thought to inhibit two processes that are essential for chromatin activation, histone acetylation and nucleosome remodeling.In order to study the role of mH2A in epigenetic control of cell differentiation during zebrafish development, we analyzed the expression pattern of the mH2A2 isoform during early embryogenesis and larval stages, at 0, 6, 12, 16, 24, 48 and 72 hours post‐fertilization (hpf). Our results revealed that mH2A2 displays maternal inheritance (0 hpf) and its transcript is expressed in all stages analyzed. Additionally, knock‐down experiments were carried out using morpholino oligonucleotides designed to block translation initiation (mH2A2MOATG) or splicing of the primary transcript (mH2A2MOSS). Both oligonucleotides generated a phenotype characterized by diminished development of anterior structures (head, eyes), somite malformation and lethality beyond 30hpf. Our results suggest that this histone variant could play a fundamental role in zebrafish development.MIFAB P04‐071‐F, Fondecyt 1070358, ECOS‐CONICYT C06B03.
Role of melatonin as essential factor of growth and proliferation in SCN cells
Authors: Hong Yonggeun , Lee Sang‐kil , Lee Youngjeon , Kim Joo‐heon 
Published: June 2021

This study was investigated to explore the effects of melatonin(N‐acetyl‐5‐methoxytryptamine) on cell proliferation and growth of SCN(suprachiasmatic nucleus) cells. The cells were cultured under 1% FBS, then treated various concentration of melatonin(10 nM, 100 nM, 1 uM, 10 uM) at indicated time points during 48 hr. Higher concentrations of melatonin(10 uM, and 1 uM) considerably inhibited the cell growth. We also found that melatonin at high concentrations(10 uM) suppressed SCN proliferation but not at low concentrations(10 nM). The cell numbers were significantly increased at 10 nM melatonin treatment(P<0.01). Furthermore, using FACS, melatonin treated cells were analyzed cell cycle, showing significantly increased the G1 phase(P<0.05) but showing decrease of S phase(P<0.05). These results indicate that melatonin induced cell proliferation and growth of SCN cells, and which was maximized at 10 nM of melatonin treated.Supported by BioGreen 21 Program(#20070401034006) from Rural development Administration, South Korea
Role of large subunit ribosomal protein L4 in ribosome maturation and cell cycle progression in Saccharomyces cerevisiae
Authors: Bommakanti Ananth S , Lindahl Lasse , Zengel Janice M 
Published: June 2021

Eukaryotic ribosome biogenesis is a highly co‐coordinated multi‐step process that requires equimolar synthesis of several rRNAs and over 50 ribosomal proteins. Until recently, ribosomal proteins were mainly considered only as structural components of the ribosomes. This view has now changed with increasing evidence indicating consistent alterations in r‐protein expression levels during tumorogenesis and in certain developmental defects.Ribosomal protein L4 is a large ribosomal subunit protein that is structurally conserved in all kingdoms of life. Furthermore, there are several reports of alteration in regulation of L4 mRNA during tissue regeneration, interaction of L4 with transcriptional factors, and varied regulation of L4 mRNA in cancer cell lines. This indicates that L4 has key extra ribosomal functions along with its role in ribosomal biogenesis and function. Here we show that in vivo depletion of Rpl4p in S. cerevisiae results in severe loss of 60S ribosomal subunits. Northern blot, primer extension, and uracil pulse‐labeling experiments suggest this might be due to a block in the processing of the 27SA3 precursor RNA into 5.8S and 25S rRNA as well as a delay in processing of 35S precursor indicating an important role in maturation of the large subunit of the ribosome. More surprisingly, depletion of Rpl4 and select few large subunit ribosomal proteins results in accumulation of multiple budded phenotype. FACS analysis further confirms accumulation of 3N peak representing the multi budded phenotype. Initial microscopic analysis shows that the Rpl4p depleted cells might be getting arrested in late anaphase / early telophase with separated nuclei but disorganized micro tubules. Further experiments are being done to characterize this phenotype and to elucidate the role of Rpl4 in this particular cell cycle defect