Medical Cell Biology Commons^™

Dysregulation Of Mir-21-Associated Mirna Regulatory Networks By Chronic Ethanol Consumption Impairs Liver Regeneration., Austin Parrish, Ankita Srivastava, Egle Juskeviciute, Jan B Hoek, Rajanikanth Vadigepalli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Impaired liver regeneration has been considered as a hallmark of progression of alcohol-associated liver disease. Our previous studies demonstrated that in vivo inhibition of the microRNA (miRNA) miR21 can restore regenerative capacity of the liver in chronic ethanol-fed animals. The present study focuses on the role of microRNA regulatory networks that are likely to mediate the miR-21 action. Rats were chronically fed an ethanol-enriched diet along with pair-fed control animals and treated with AM21 (anti-miR-21), a locked nucleic acid antisense to miR-21. Partial hepatectomy (PHx) was performed and miRNA expression profiling over the course of liver regeneration was assessed. Our …

Resident Immune Cells Of The Avascular Lens: Mediators Of The Injury And Fibrotic Response Of The Lens., A. Menko, Jodirae Dedreu, Caitlin M. Logan, Heather Paulson, Alex V Levin, Janice L Walker

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Tissues typically harbor subpopulations of resident immune cells that function as rapid responders to injury and whose activation leads to induction of an adaptive immune response, playing important roles in repair and protection. Since the lens is an avascular tissue, it was presumed that it was absent of resident immune cells. Our studies now show that resident immune cells are a shared feature of the human, mouse, and chicken lens epithelium. These resident immune cells function as immediate responders to injury and rapidly populate the wound edge following mock cataract surgery to function as leader cells. Many of these resident …

Characterization And Clinical Significance Of Eif1ax Mutations And Co-Mutations In Cytologically Indeterminate Thyroid Nodules: A 5-Year Retrospective Analysis., Stacey Gargano, Nitika Badjatia, Yanina Nikolaus, Stephen C Peiper, Zi-Xuan Wang, Phd

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

OBJECTIVE: Mutations in the EIF1AX gene have been recently detected in a small percentage of benign and malignant thyroid lesions. We sought to investigate the prevalence and clinical significance of EIF1AX mutations and co-mutations in cytologically indeterminate thyroid nodules at our institution.

MATERIALS AND METHODS: A 5-year retrospective analysis was performed on thyroid nodules with a cytologic diagnosis of Bethesda category III or IV, which had undergone testing by our in-house next generation sequencing panel. Surgically resected nodules with EIF1AX mutations were identified, and mutation type and presence of co-mutations were correlated with histopathologic diagnosis.

RESULTS: 41/904 (4.5%) cases overall …

Discoidin Domain Receptor 1 Functionally Interacts With The Igf-I System In Bladder Cancer, Simone Buraschi, Alaide Morcavallo, Thomas Neill, Manuela Stefanello, Chiara Palladino, Shi-Qiong Xu, Antonino Belfiore, Renato V. Iozzo, Andrea Morrione

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

No abstract provided.

Single-Cell Gene Expression Analysis Identifies Chronic Alcohol-Mediated Shift In Hepatocyte Molecular States After Partial Hepatectomy., Sirisha Achanta, Aalap Verma, Ankita Srivastava, Harshavardhan Nilakantan, Jan B. Hoek, Rajanikanth Vadigepalli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The analysis of molecular states of individual cells, as defined by their mRNA expression profiles and protein composition, has gained widespread interest in studying biological phenomena ranging from embryonic development to homeostatic tissue function and genesis and evolution of cancers. Although the molecular content of individual cells in a tissue can vary widely, their molecular states tend to be constrained within a transcriptional landscape partly described by the canonical archetypes of a population of cells. In this study, we sought to characterize the effects of an acute (partial hepatectomy) and chronic (alcohol consumption) perturbation on the molecular states of individual …

Silencing Of The Pink1 Gene Expression By Conditional Rnai Does Not Induce Dopaminergic Neuron Death In Mice., Hongxia Zhou, Björn H Falkenburger, Jörg B Schulz, Kim Tieu, Zuoshang Xu, Xu Gang Xia

Kim Tieu

Transgenic RNAi, an alternative to the gene knockout approach, can induce hypomorphic phenotypes that resemble those of the gene knockout in mice. Conditional transgenic RNAi is an attractive choice of method for reverse genetics in vivo because it can achieve temporal and spatial silencing of targeted genes. Pol III promoters such as U6 are widely used to drive the expression of RNAi transgenes in animals. Tested in transgenic mice, a Cre-loxP inducible U6 promoter drove the broad expression of an shRNA against the Pink1 gene whose loss-of-functional mutations cause one form of familial Parkinson's disease. The expression of the shRNA …

Single-Cell Transcriptional Analysis Reveals Novel Neuronal Phenotypes And Interaction Networks Involved In The Central Circadian Clock., James Park, Haisun Zhu, Sean O'Sullivan, Babatunde A Ogunnaike, David R Weaver, James S. Schwaber, Rajanikanth Vadigepalli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Single-cell heterogeneity confounds efforts to understand how a population of cells organizes into cellular networks that underlie tissue-level function. This complexity is prominent in the mammalian suprachiasmatic nucleus (SCN). Here, individual neurons exhibit a remarkable amount of asynchronous behavior and transcriptional heterogeneity. However, SCN neurons are able to generate precisely coordinated synaptic and molecular outputs that synchronize the body to a common circadian cycle by organizing into cellular networks. To understand this emergent cellular network property, it is important to reconcile single-neuron heterogeneity with network organization. In light of recent studies suggesting that transcriptionally heterogeneous cells organize into distinct cellular …

Mirna-145 Increases Therapeutic Sensibility To Gemcitabine Treatment Of Pancreatic Adenocarcinoma Cells., Yong Lin, Xin Ge, Yiyang Wen, Zhu-Mei Shi, Qiu-Dan Chen, Min Wang, Ling-Zhi Liu, Bing-Hua Jiang, Yuan Lu

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Pancreatic adenocarcinoma is one of the most leading causes of cancer-related deaths worldwide. Although recent advances provide various treatment options, pancreatic adenocarcinoma has poor prognosis due to its late diagnosis and ineffective therapeutic multimodality. Gemcitabine is the effective first-line drug in pancreatic adenocarcinoma treatment. However, gemcitabine chemoresistance of pancreatic adenocarcinoma cells has been a major obstacle for limiting its treatment effect. Our study found that p70S6K1 plays an important role in gemcitabine chemoresistence. MiR-145 is a tumor suppressor which directly targets p70S6K1 for inhibiting its expression in pancreatic adenocarcinoma, providing new therapeutic scheme. Our findings revealed a new mechanism underlying …

Use Of Propensity Score Matching To Identify A Strong Association Between Strategic Concentration To Mitochondria-Sr Associations Of The Mitochondrial Ca2+ Uniporter: Ca2+ Uptake Hotspots In The Cardiac Mitochondria, Sergio De La Fuente, Caitlin Vail, Elorm J. Agra, Kira Holmstrom, Junhui Sun, Jyotsna Mishra, Toren Kinkel, Elizabeth Murphy, Suresh K. Joseph, Shey-Shing Shen, György Csordás

Department of Pathology, Anatomy, and Cell Biology Posters

Introduction:

• Control of the mitochondrial ATP production by SR-derived Ca²⁺ signals includes local, nanodomain Ca²⁺ transfer from ryanodine receptors (RyR2) to the mitochondrial matrix (excitation-bioenergetics coupling).
• Ca²⁺ crosses the inner mitochondrial membrane (IMM) via the mtCU, a low-affinity Ca²⁺-activated Ca²⁺ channel complex.
• The surface area of cardiac IMM is extensively enhanced by cristae folding; however, mitoplast patch clamp studies showed mtCU current density the lowest amongst a range of tissues (Fieni 2012. Nat Commun).

Gaining Competencies During Early Medical Training: Medical Students As Teaching Assistants In Dissection-Based Anatomy Course, Martin T. Brown, Bruce Fenderson, Guiyan Zhang

Department of Pathology, Anatomy, and Cell Biology Posters

Introduction and Objectives

• In 2002, ACGME identified six ACGME Core Competencies: patient care; medical knowledge; practice-based learning and improvement; interpersonal and communication skills; professionalism; and systems-based practice.
• AAMC recommended lists of similar competencies for the curricula of medical schools. Competency based curricula have been widely implemented in medical schools.
• Effective shifting in the graduate medical educational programs has been reported in various clinical specialties.
• There is a lack of reported efforts and development on competency training in early preclinical years of medical education.

Objectives:

• To explore methods for strengthening medical students’ competency training during preclinical undergraduate medical education.
• To measure …

Micu1 Regulation Of Mitochondrial Ca(2+) Uptake Dictates Survival And Tissue Regeneration., Anil Noronha Antony, Melanie Paillard, Cynthia Moffat, Egle Juskeviciute, Jason Correnti, Brad Bolon, Emanual Rubin, Md, György Csordás, Erin L Seifert, Jan B. Hoek, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Mitochondrial Ca(2+) uptake through the recently discovered Mitochondrial Calcium Uniporter (MCU) is controlled by its gatekeeper Mitochondrial Calcium Uptake 1 (MICU1). However, the physiological and pathological role of MICU1 remains unclear. Here we show that MICU1 is vital for adaptation to postnatal life and for tissue repair after injury. MICU1 knockout is perinatally lethal in mice without causing gross anatomical defects. We used liver regeneration after partial hepatectomy as a physiological stress response model. Upon MICU1 loss, early priming is unaffected, but the pro-inflammatory phase does not resolve and liver regeneration fails, with impaired cell cycle entry and extensive necrosis. …

Cells Activated For Wound Repair Have The Potential To Direct Collective Invasion Of An Epithelium., Brigid M Bleaken, A Sue Menko, Janice Walker

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Mechanisms regulating how groups of cells are signaled to move collectively from their original site and invade surrounding matrix are poorly understood. Here we develop a clinically relevant ex vivo injury invasion model to determine whether cells involved in directing wound healing have invasive function and whether they can act as leader cells to direct movement of a wounded epithelium through a three-dimensional (3D) extracellular matrix (ECM) environment. Similar to cancer invasion, we found that the injured cells invade into the ECM as cords, involving heterotypical cell-cell interactions. Mesenchymal cells with properties of activated repair cells that typically locate to …

In-Silico Identification Of Prognostically Inversely Correlated Mirnas And Mrnas (Pic’S) In Multiple Cancers, Chirayu Pankaj Goswami, Zi-Xuan Wang

Department of Pathology, Anatomy, and Cell Biology Posters

Despite numerous methods available to identify potential mRNA targets for miRNAs, prognostic relationship of these molecules in diseases like cancers where deregulation of gene expression is a major pathogenic factor, has not yet been emphasized. We performed in-silico identification of prognostically inversely correlated miRNA - mRNA pairs (PIC’s) in multiple cancers using expression data from The Cancer Genome Atlas. Partners in a PIC show inverse correlation of expression and opposite hazard implication. Using a three step approach, we identified a total of 1,253,443 PIC’s from 23 cancer types, several of which have previously been shown to have a predicted or …

Intracellular Information Processing Through Encoding And Decoding Of Dynamic Signaling Features., Hirenkumar K Makadia, James S. Schwaber, Rajanikanth Vadigepalli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Cell signaling dynamics and transcriptional regulatory activities are variable within specific cell types responding to an identical stimulus. In addition to studying the network interactions, there is much interest in utilizing single cell scale data to elucidate the non-random aspects of the variability involved in cellular decision making. Previous studies have considered the information transfer between the signaling and transcriptional domains based on an instantaneous relationship between the molecular activities. These studies predict a limited binary on/off encoding mechanism which underestimates the complexity of biological information processing, and hence the utility of single cell resolution data. Here we pursue a …

Gsk-3Β Regulates Tumor Growth And Angiogenesis In Human Glioma Cells., Peng Zhao, Qi Li, Zhumei Shi, Charlie Li, Lin Wang, Xue Liu, Chengfei Jiang, Xu Qian, Yongping You, Ning Liu, Ling-Zhi Liu, Lianshu Ding, Bing-Hua Jiang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Glioma accounts for the majority of primary malignant brain tumors in adults.

METHODS: Glioma specimens and normal brain tissues were analyzed for the expression levels of GSK-3β and p-GSK-3β (Ser9) by tissue microarray analysis (TMA) and Western blotting. Glioma cells over-expressing GSK-3β were used to analyze biological functions both in vitro and in vivo.

RESULTS: The levels of p-GSK-3β (Ser9), but not total GSK-3β, are significantly up-regulated in glioma tissues compared to normal tissues, and are significantly correlated with the glioma grades. Ectopic expression of GSK-3β decreased the phosphorylation levels of mTOR and p70S6K1; and inhibited β-catenin, HIF-1α and …

Mir-497 Decreases Cisplatin Resistance In Ovarian Cancer Cells By Targeting Mtor/P70s6k1., Shaohua Xu, Guang-Bo Fu, Zhen Tao, Jun Ouyang, Fanfei Kong, Bing-Hua Jiang, Xiaoping Wan, Ke Chen

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The mechanism of cisplatin resistance in ovarian cancer is not clearly understood. In the present investigation, we found that the expression levels of miR-497 were reduced in chemotherapy-resistant ovarian cancer cells and tumor tissues due to hypermethylation of miR-497 promoter. Low miR-497 expression levels were associated with chemo-resistant phonotype of ovarian cancer. By analyzing the expression levels of miR-497, mTOR and p70S6K1 in a clinical gene-expression array dataset, we found that mTOR and p70S6K1, two proteins correlated to chemotherapy-resistance in multiple types of human cancers, were inversely correlated with miR-497 levels in ovarian cancer tissues. By using an orthotopic ovarian …

Hormone-Induced Calcium Oscillations Depend On Cross-Coupling With Inositol 1,4,5-Trisphosphate Oscillations., Lawrence D Gaspers, Paula J Bartlett, Antonio Politi, Paul Burnett, Walson Metzger, Jane Johnston, Suresh K Joseph, Thomas Höfer, Andrew P Thomas

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Receptor-mediated oscillations in cytosolic Ca(2+) concentration ([Ca(2+)]i) could originate either directly from an autonomous Ca(2+) feedback oscillator at the inositol 1,4,5-trisphosphate (IP3) receptor or as a secondary consequence of IP3 oscillations driven by Ca(2+) feedback on IP3 metabolism. It is challenging to discriminate these alternatives, because IP3 fluctuations could drive Ca(2+) oscillations or could just be a secondary response to the [Ca(2+)]i spikes. To investigate this problem, we constructed a recombinant IP3 buffer using type-I IP3 receptor ligand-binding domain fused to GFP (GFP-LBD), which buffers IP3 in the physiological range. This IP3 buffer slows hormone-induced [IP3] dynamics without changing steady-state …

Bcl2 Expression And Bcl2/Myc Dual Expression Predicts Inferior Survival In Primary Central Nervous System Lymphoma, Guldeep Uppal, Md, Zi-Xuan (Zoe) Wang, Phd, Renu Bajaj, Phd, Mark T. Curtis, Md, Phd, Charalambos C. Solomides, Md, Jon Glass, Md, Peter M. Banks, Stephen C. Peiper, Md, Jerald Z. Gong, Md

Department of Pathology, Anatomy, and Cell Biology Resident's Posters

Background

Primary CNS lymphoma (PCNSL) is a rare type of diffuse large B-cell lymphoma (DLBCL) arising from and usually confined to CNS. Understating of the pathogenesis and prognostic markers is a challenge due to rarity of this neoplasm and paucity of the material available to study. Recent studies have shown that dual expression of MYC and BCL2 in DLBCL contributes to inferior overall survival. The prognostic value of MYC and BCL2 in PCNSL is not well studied.

Proline-Rich Tyrosine Kinase 2 (Pyk2) Regulates Igf-I-Induced Cell Motility And Invasion Of Urothelial Carcinoma Cells, Marco Genua, Shi-Qiong Xu, Simone Buraschi, Stephen C. Peiper, Leonard G. Gomella, Antonio Belfiore, Renato V. Iozzo, Andrea Morrione

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The insulin-like growth factor receptor I (IGF-IR) plays an essential role in transformation by promoting cell growth and protecting cancer cells from apoptosis. We have recently demonstrated that the IGF-IR is overexpressed in invasive bladder cancer tissues and promotes motility and invasion of urothelial carcinoma cells. These effects require IGF-I-induced Akt- and MAPK-dependent activation of paxillin. The latter co-localizes with focal adhesion kinases (FAK) at dynamic focal adhesions and is critical for promoting motility of urothelial cancer cells. FAK and its homolog Proline-rich tyrosine kinase 2 (Pyk2) modulate paxillin activation; however, their role in regulating IGF-IR-dependent signaling and motility in …

Transcriptional Regulatory Network Analysis During Epithelial-Mesenchymal Transformation Of Retinal Pigment Epithelium., Craig H Pratt, Rajanikanth Vadigepalli, Praveen Chakravarthula, Gregory E Gonye, Nancy J Philp, Gerald B Grunwald

Rajanikanth Vadigepalli

PURPOSE: Phenotypic transformation of retinal pigment epithelial (RPE) cells contributes to the onset and progression of ocular proliferative disorders such as proliferative vitreoretinopathy (PVR). The formation of epiretinal membranes in PVR may involve an epithelial-mesenchymal transformation (EMT) of RPE cells as part of an aberrant wound healing response. While the underlying mechanism remains unclear, this likely involves changes in RPE cell gene expression under the control of specific transcription factors (TFs). Thus, the purpose of the present study was to identify TFs that may play a role in this process. METHODS: Regulatory regions of genes that are differentially regulated during …

Blood-Brain Barrier Abnormalities Caused By Hiv-1 Gp120: Mechanistic And Therapeutic Implications., Jean-Pierre Louboutin, David S Strayer

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The blood-brain barrier (BBB) is compromised in many systemic and CNS diseases, including HIV-1 infection of the brain. We studied BBB disruption caused by HIV-1 envelope glycoprotein 120 (gp120) as a model. Exposure to gp120, whether acute [by direct intra-caudate-putamen (CP) injection] or chronic [using SV(gp120), an experimental model of ongoing production of gp120] disrupted the BBB, and led to leakage of vascular contents. Gp120 was directly toxic to brain endothelial cells. Abnormalities of the BBB reflect the activity of matrix metalloproteinases (MMPs). These target laminin and attack the tight junctions between endothelial cells and BBB basal laminae. MMP-2 and …

Switches, Excitable Responses And Oscillations In The Ring1b/Bmi1 Ubiquitination System., Lan K Nguyen, Javier Muñoz-García, Helene Maccario, Aaron Ciechanover, Walter Kolch, Boris N Kholodenko

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

In an active, self-ubiquitinated state, the Ring1B ligase monoubiquitinates histone H2A playing a critical role in Polycomb-mediated gene silencing. Following ubiquitination by external ligases, Ring1B is targeted for proteosomal degradation. Using biochemical data and computational modeling, we show that the Ring1B ligase can exhibit abrupt switches, overshoot transitions and self-perpetuating oscillations between its distinct ubiquitination and activity states. These different Ring1B states display canonical or multiply branched, atypical polyubiquitin chains and involve association with the Polycomb-group protein Bmi1. Bistable switches and oscillations may lead to all-or-none histone H2A monoubiquitination rates and result in discrete periods of gene (in)activity. Switches, overshoots …

Mir-21 Induced Angiogenesis Through Akt And Erk Activation And Hif-1Α Expression., Ling-Zhi Liu, Chongyong Li, Qi Chen, Yi Jing, Richard Carpenter, Yue Jiang, Hsiang-Fu Kung, Lihui Lai, Bing-Hua Jiang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

MicroRNAs (miRNAs) are endogenous, small noncoding RNAs that play important roles in various cellular functions and tumor development. Recent studies have indicated that miR-21 is one of the important miRNAs associated with tumor growth and metastasis, but the role and molecular mechanism of miR-21 in regulating tumor angiogenesis remain to be elucidated. In this study, miR-21 was overexpressed by transfecting pre-miR-21 into human prostate cancer cells and tumor angiogenesis was assayed using chicken chorioallantoic membrane (CAM). We found that overexpression of miR-21 in DU145 cells increased the expression of HIF-1α and VEGF, and induced tumor angiogenesis. AKT and extracellular regulated …

Evidence-Based Genomic Diagnosis Characterized Chromosomal And Cryptic Imbalances In 30 Elderly Patients With Myelodysplastic Syndrome And Acute Myeloid Leukemia., Renu Bajaj, Fang Xu, Bixia Xiang, Katherine Wilcox, Autumn J Diadamo, Rachana Kumar, Alexandra Pietraszkiewicz, Stephanie Halene, Peining Li

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: To evaluate the clinical validity of genome-wide oligonucleotide array comparative genomic hybridization (aCGH) for detecting somatic abnormalities, we have applied this genomic analysis to 30 cases (13 MDS and 17 AML) with clonal chromosomal abnormalities detected in more than 50% of analyzed metaphase cells.

RESULTS: The aCGH detected all numerical chromosomal gains and losses from the mainline clones and 113 copy number alterations (CNAs) ranging from 0.257 to 102.519 megabases (Mb). Clinically significant recurrent deletions of 5q (involving the RPS14 gene), 12p12.3 (ETV6 gene), 17p13 (TP53 gene), 17q11.2 (NF1 gene) and 20q, double minutes containing the MYC gene and …

Acetate Causes Alcohol Hangover Headache In Rats., Christina R Maxwell, Rebecca Jay Spangenberg, Jan B Hoek, Stephen D Silberstein, Michael L Oshinsky

Department of Neurology Faculty Papers

BACKGROUND: The mechanism of veisalgia cephalgia or hangover headache is unknown. Despite a lack of mechanistic studies, there are a number of theories positing congeners, dehydration, or the ethanol metabolite acetaldehyde as causes of hangover headache.

METHODS: We used a chronic headache model to examine how pure ethanol produces increased sensitivity for nociceptive behaviors in normally hydrated rats.

RESULTS: Ethanol initially decreased sensitivity to mechanical stimuli on the face (analgesia), followed 4 to 6 hours later by inflammatory pain. Inhibiting alcohol dehydrogenase extended the analgesia whereas inhibiting aldehyde dehydrogenase decreased analgesia. Neither treatment had nociceptive effects. Direct administration of acetate …

Intra-Tumor Heterogeneity Of Mlh1 Promoter Methylation Revealed By Deep Single Molecule Bisulfite Sequencing., Katherine E Varley, David G Mutch, Tina B Edmonston, Paul J Goodfellow, Robi D Mitra

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

A single tumor may contain cells with different somatic mutations. By characterizing this genetic heterogeneity within tumors, advances have been made in the prognosis, treatment and understanding of tumorigenesis. In contrast, the extent of epigenetic intra-tumor heterogeneity and how it influences tumor biology is under-explored. We have characterized epigenetic heterogeneity within individual tumors using next-generation sequencing. We used deep single molecule bisulfite sequencing and sample-specific DNA barcodes to determine the spectrum of MLH1 promoter methylation across an average of 1000 molecules in each of 33 individual samples in parallel, including endometrial cancer, matched blood and normal endometrium. This first glimpse, …

Transcriptional Regulatory Network Analysis During Epithelial-Mesenchymal Transformation Of Retinal Pigment Epithelium., Craig H Pratt, Rajanikanth Vadigepalli, Praveen Chakravarthula, Gregory E Gonye, Nancy J Philp, Gerald B Grunwald

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

PURPOSE: Phenotypic transformation of retinal pigment epithelial (RPE) cells contributes to the onset and progression of ocular proliferative disorders such as proliferative vitreoretinopathy (PVR). The formation of epiretinal membranes in PVR may involve an epithelial-mesenchymal transformation (EMT) of RPE cells as part of an aberrant wound healing response. While the underlying mechanism remains unclear, this likely involves changes in RPE cell gene expression under the control of specific transcription factors (TFs). Thus, the purpose of the present study was to identify TFs that may play a role in this process.

METHODS: Regulatory regions of genes that are differentially regulated during …

Silencing Of The Pink1 Gene Expression By Conditional Rnai Does Not Induce Dopaminergic Neuron Death In Mice., Hongxia Zhou, Björn H Falkenburger, Jörg B Schulz, Kim Tieu, Zuoshang Xu, Xu Gang Xia

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Transgenic RNAi, an alternative to the gene knockout approach, can induce hypomorphic phenotypes that resemble those of the gene knockout in mice. Conditional transgenic RNAi is an attractive choice of method for reverse genetics in vivo because it can achieve temporal and spatial silencing of targeted genes. Pol III promoters such as U6 are widely used to drive the expression of RNAi transgenes in animals. Tested in transgenic mice, a Cre-loxP inducible U6 promoter drove the broad expression of an shRNA against the Pink1 gene whose loss-of-functional mutations cause one form of familial Parkinson's disease. The expression of the shRNA …

Myosin Heavy Chain And Physiological Adaptation Of The Rat Diaphragm In Elastase-Induced Emphysema., Dong Kwan Kim, Jianliang Zhu, Benjamin W Kozyak, James M Burkman, Neal A Rubinstein, Edward B Lankford, Hansell H Stedman, Taitan Nguyen, Sanford Levine, Joseph B Shrager

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Several physiological adaptations occur in the respiratory muscles in rodent models of elastase-induced emphysema. Although the contractile properties of the diaphragm are altered in a way that suggests expression of slower isoforms of myosin heavy chain (MHC), it has been difficult to demonstrate a shift in MHCs in an animal model that corresponds to the shift toward slower MHCs seen in human emphysema. METHODS: We sought to identify MHC and corresponding physiological changes in the diaphragms of rats with elastase-induced emphysema. Nine rats with emphysema and 11 control rats were studied 10 months after instillation with elastase. MHC isoform …