Translational Medical Research Commons^™

Inflammatory Serine Proteases Play A Critical Role In The Early Pathogenesis Of Diabetic Cardiomyopathy., Mikhail A Kolpakov, Kunal Sikder, Amrita Sarkar, Shaswati Chaki, Sanket K Shukla, Xinji Guo, Zhao Qi, Carlos Barbery, Abdelkarim Sabri, Khadija Rafiq

Center for Translational Medicine Faculty Papers

BACKGROUND/AIMS: Diabetic cardiomyopathy (DCM) is characterized by structural and functional alterations that can lead to heart failure. Several mechanisms are known to be involved in the pathogenesis of DCM, however, the molecular mechanism that links inflammation to DCM is incompletely understood. To learn about this mechanism, we investigated the role of inflammatory serine proteases (ISPs) during the development of DCM.

METHODS: Eight weeks old mice with deletion of dipeptidyl peptidase I (DPPI), an enzyme involved in the maturation of major ISPs, and wild type (WT) mice controls were injected with streptozotocin (50 mg/kg for 5 days intraperitoneally) and studied after …

Α-Catenin-Dependent Cytoskeletal Tension Controls Yap Activity In The Heart., Alexia Vite, Caimei Zhang, Roslyn Yi, Sabrina Emms, Glenn L. Radice

Center for Translational Medicine Faculty Papers

Shortly after birth, muscle cells of the mammalian heart lose their ability to divide. At the same time, the N-cadherin/catenin cell adhesion complex accumulates at the cell termini, creating a specialized type of cell-cell contact called the intercalated disc (ICD). To investigate the relationship between ICD maturation and proliferation, αE-catenin (Ctnna1) and αT-catenin (Ctnna3) genes were deleted to generate cardiac-specific α-catenin double knockout (DKO) mice. DKO mice exhibited aberrant N-cadherin expression, mislocalized actomyosin activity and increased cardiomyocyte proliferation that was dependent on Yap activity. To assess effects on tension, cardiomyocytes were cultured on deformable polyacrylamide hydrogels of varying stiffness. When …

Beta-Catenin Cleavage Enhances Transcriptional Activation, Tatiana Goretsky, Emily M. Bradford, Qing Ye, Olivia F. Lamping, Tomas Vanagunas, Mary Pat Moyer, Patrick C. Keller, Preetika Sinh, Josep M. Llovet, Tianyan Gao, Qing-Bai She, Linheng Li, Terrence A. Barrett

Internal Medicine Faculty Publications

Nuclear activation of Wnt/β-catenin signaling is required for cell proliferation in inflammation and cancer. Studies from our group indicate that β-catenin activation in colitis and colorectal cancer (CRC) correlates with increased nuclear levels of β-catenin phosphorylated at serine 552 (pβ-Cat⁵⁵²). Biochemical analysis of nuclear extracts from cancer biopsies revealed the existence of low molecular weight (LMW) pβ-Cat⁵⁵², increased to the exclusion of full size (FS) forms of β-catenin. LMW β-catenin lacks both termini, leaving residues in the armadillo repeat intact. Further experiments showed that TCF4 predominantly binds LMW pβ-Cat⁵⁵² in the nucleus of inflamed and …

Endothelium In The Pharyngeal Arches 3, 4 And 6 Is Derived From The Second Heart Field., Xia Wang, Dongying Chen, Kelley Chen, Ali Jubran, Annjosette Ramirez, Sophie Astrof

Center for Translational Medicine Faculty Papers

Oxygenated blood from the heart is directed into the systemic circulation through the aortic arch arteries (AAAs). The AAAs arise by remodeling of three symmetrical pairs of pharyngeal arch arteries (PAAs), which connect the heart with the paired dorsal aortae at mid-gestation. Aberrant PAA formation results in defects frequently observed in patients with lethal congenital heart disease. How the PAAs form in mammals is not understood. The work presented in this manuscript shows that the second heart field (SHF) is the major source of progenitors giving rise to the endothelium of the pharyngeal arches 3 - 6, while the endothelium …

Neural Crest Cell-Autonomous Roles Of Fibronectin In Cardiovascular Development., Xia Wang, Sophie Astrof

Department of Medicine Faculty Papers

The chemical and mechanical properties of extracellular matrices (ECMs) modulate diverse aspects of cellular fates; however, how regional heterogeneity in ECM composition regulates developmental programs is not well understood. We discovered that fibronectin 1 (Fn1) is expressed in strikingly non-uniform patterns during mouse development, suggesting that regionalized synthesis of the ECM plays cell-specific regulatory roles during embryogenesis. To test this hypothesis, we ablated Fn1 in the neural crest (NC), a population of multi-potent progenitors expressing high levels of Fn1. We found that Fn1 synthesized by the NC mediated morphogenesis of the aortic arch artery and differentiation of NC cells into …

Fibronectin Signals Through Integrin Α5Β1 To Regulate Cardiovascular Development In A Cell Type-Specific Manner., Dongying Chen, Xia Wang, Dong Liang, Julie Gordon, Ashok Mittal, Nancy Manley, Karl Degenhardt, Sophie Astrof

Department of Medicine Faculty Papers

Fibronectin (Fn1) is an evolutionarily conserved extracellular matrix glycoprotein essential for embryonic development. Global deletion of Fn1 leads to mid-gestation lethality from cardiovascular defects. However, severe morphogenetic defects that occur early in embryogenesis in these embryos precluded assigning a direct role for Fn1 in cardiovascular development. We noticed that Fn1 is expressed in strikingly non-uniform patterns during mouse embryogenesis, and that its expression is particularly enriched in the pharyngeal region corresponding with the pharyngeal arches 3, 4, and 6. This region bears a special importance for the developing cardiovascular system, and we hypothesized that the localized enrichment of Fn1 in …