Amino Acids, Peptides, and Proteins Commons^™

Comparative Mass Spectrometry Analysis Of High And Low Centrifugation Extracellular Vesicle (Ev) Pellets From Healthy Urine Following Tamm-Horsfall Protein Removal, Dana Bielopolski, Luca Musante, Henrik Molina, Douglas Barrows, Samantha Upson, Lifang Yang, Thomas Carrol, Jonathan N. Tobin, Rhonda G. Kost, U. Erdbrügger

Department of Biomedical and Translational Sciences Faculty Publications

Objectives

Urinary extracellular vesicles (uEVs) are potential biomarkers for renal physiology and disease. Their isolation is challenged by Tamm-Horsfall protein (THP) contamination, particularly in high-speed ultracentrifugation (P100) fractions. Low-speed (P20) fractions contain biologically relevant uEVs, yet their proteomic composition is underexplored. This study evaluates strategies for THP removal to optimize mass spectrometry analysis and characterizes P20 and P100 uEV proteomes and its combination in healthy urine.

Methods

Urine from a healthy volunteer was processed via sequential centrifugation at 21,200 g (P20) and 164,244 g (P100). THP removal was performed using low ionic strength buffer (P20) and size-exclusion chromatography (P100). Western …

P38 Mapk Is Involved In Epigenetic Regulation Of Fibrotic Genes In Replication Induced Senescence In Lung Fibroblasts, Shan Zhu, Jennifer Q. Zhou, Kan Wang, Ming-Lei Guo, Yan Sanders

Department of Biomedical and Translational Sciences Faculty Publications

Fibroblast activation is essential for tissue repair following injury; however, prolonged activation drives pathological fibrosis. Idiopathic pulmonary fibrosis (IPF), a progressive and age-associated lung disease, is characterized by aberrant fibroblast activation, with increasing evidence implicating senescent and near-senescent fibroblasts in its pathogenesis. However, the underlying mechanisms remain poorly defined. In this study, we investigated whether histone modification is involved in TGF-β1 treated lung fibroblasts and contributes to the fibrotic phenotype. Human IMR90 lung fibroblasts at low and high population doubling levels (LPDL and HPDL), as well as primary IPF fibroblasts, were used in this study. In response to TGF-β1, both …

Localization And Functional Exploration Of Leiomodin-2'S C-Terminal Binding Sites, Mason D. Summers, Madison Little, Robert P. Young, Brayan Osegueda, Alan Palma Guillen, Garry E. Smith Jr., John R. Cart, Vitold E. Galkin, Alla S. Kostyukova

Department of Biomedical and Translational Sciences Faculty Publications

Striated muscle contraction occurs through interactions between overlapping myosin-based thick and actin-based thin filaments within the sarcomere. For effective contraction to occur, the length of the thin filament must be maintained to ensure sufficient overlap with the thick filament. The proteins leiomodin and tropomodulin compete for binding at the pointed ends of thin filaments to regulate their length, using their homologous N-terminal actin and tropomyosin binding sites. Leiomodin also contains a region called the C-terminal extension, absent in tropomodulin. In this region, the cardiac isoform (leiomodin-2) contains additional actin-binding sites that enable it to bind along the sides of thin …

The Central Role For Troponin C Amino-Terminal ⍺-Helix In Vertebrate Thin Filiment Ca²⁺-Activation, Yun Shi, Lauren A. Blackwell, Ryan K. Schroy, B. Max Cleland, Cristina M. Risi, Michelle S. Parvatiyar, Jose R. Pinto, Vitold E. Galkin, P. Bryant Chase

Department of Biomedical and Translational Sciences Faculty Publications

Troponin C (TnC) is the Ca²⁺-sensing subunit of troponin that is responsible for activating thin filaments in striated muscle, and, in turn, for regulating the systolic and diastolic contractile function of cardiac muscle. The secondary structure of vertebrate TnC is mainly composed of α-helices, with nine helices named sequentially, starting from the amino terminus, from N to A–H. The N-helix is a 12-residue-long α-helix located at the extreme amino terminus of the protein and is the only helical structure that does not participate in forming Ca²⁺-binding EF-hands. Evolutionarily, the N-helix is found only in TnC from mammalian species and most …

Neurotensin Regulates Primate Ovulation Via Multiple Neurotensin Receptors, Andrew C. Pearson, Jessica S. Miller, Hannah J. Jensen, Ketan Shrestha, Thomas E. Curry Jr., Diane M. Duffy

Department of Biomedical and Translational Sciences Faculty Publications

Neurotensin (NTS), a small neuropeptide, was recently established as a key paracrine mediator of ovulation. NTS mRNA is highly expressed by granulosa cells in response to the luteinizing hormone (LH) surge, and multiple NTS receptors are expressed by cells of the ovulatory follicle. To identify the role of NTS receptors NTSR1 and SORT1 in ovulation in vivo, the dominant follicle of cynomolgus macaques (Macaca fascicularis) was injected with either vehicle control, the general NTS receptor antagonist SR142948, the NTSR1-selective antagonist SR48692, or the SORT1-selective antagonist AF38469. Human chorionic gonadotropin (hCG) was then administered to initiate ovulatory events. …

Interaction Of Cardiac Leiomodin With The Native Cardiac Thin Filament, Madison Little, Cristina M. Risi, Tania M. Larrinaga, Mason D. Summers, Tyler Nguyen, Garry E. Smith Jr., Jennifer Atherton, Carol C. Gregorio, Alla S. Kostyukova, Vitold E. Galkin

Department of Biomedical and Translational Sciences Faculty Publications

Every heartbeat depends on cyclical contraction-relaxation produced by the interactions between myosin-containing thick and actin-based thin filaments (TFs) arranged into a crystalline-like lattice in the cardiac sarcomere. Therefore, the maintenance of thin filament length is crucial for myocardium function. The thin filament is comprised of an actin backbone, the regulatory troponin complex and tropomyosin that controls interactions between thick and thin filaments. Thin filament length is controlled by the tropomodulin family of proteins; tropomodulin caps pointed ends of thin filaments, and leiomodin (Lmod) promotes elongation of thin filaments by a “leaky-cap” mechanism. The broader distribution of Lmod on the thin …

Swinging Lever Mechanism Of Myosin Directly Shown By Time-Resolved Cryo-Em, David P. Klebl, Sean N. Mcmillan, Cristina Risi, Eva Forgacs, Betty Virok, Jennifer L. Atherton, Sarah A. Harris, Michele Stofella, Donald A. Winkelmann, Frank Sobott, Vitold E. Galkin, Peter J. Knight, Stephen P. Muench, Charlotte A. Scarfi, Howard D. White

Department of Biomedical and Translational Sciences Faculty Publications

Myosins produce force and movement in cells through interactions with F-actin¹. Generation of movement is thought to arise through actin-catalysed conversion of myosin from an ATP-generated primed (pre-powerstroke) state to a post-powerstroke state, accompanied by myosin lever swing²,³. However, the initial, primed actomyosin state has never been observed, and the mechanism by which actin catalyses myosin ATPase activity is unclear. Here, to address these issues, we performed time-resolved cryogenic electron microscopy (cryo-EM)⁴ of a myosin-5 mutant having slow hydrolysis product release⁵,⁶. Primed actomyosin was predominantly captured 10 ms after …

Deletion Of Chop In Beta Cell Protects Mice From Cardiovascular Complications In Type 2 Diabetes: Evidence From A Pre-Clinical Mouse Model, Balaji Srinivas, Kiran Alluri, Nour-Eddine Rhaleb, Khalid Matrougui

Department of Biomedical and Translational Sciences Faculty Publications

Introduction

Cardiovascular complications are the leading cause of morbidity and mortality in patients with type 2 diabetes (T2D), which is recognized as a major independent risk factor for coronary artery disease, stroke, peripheral vascular disease, and heart failure. The interrelationship between metabolic dysfunction and cardiovascular disease is complex and multifactorial, involving hyperglycemia, insulin resistance, inflammation, and oxidative stress. Evidence indicates that endoplasmic reticulum (ER) stress and induction of the unfolded protein response (UPR) contribute to metabolic dysregulation and vascular dysfunction. However, the specific role of beta cell-derived UPR mediators, particularly C/EBP homologous protein (CHOP), in coordinating this interorgan axis between …

Phenotype Specific Nuclear Lamina Remodeling In Hipsc Derived Cardiomyocytes Bearing Tnnt2 Sarcomeric Variants, Isabella Leite Coscarella, Olalekan H. Usman, Lili Wang, Maicon Landim-Vieira, Lillian Wirstiuk, Amber N. Brown, Diego A. R. Zorio, Brian K. Washburn, Cynthia Vied, Bjorn C. Knollmann, Christopher Solís, Vitold E. Galkin, P. Bryant Chase, J. Travis Hinson, Jerome Irianto, Jose Renato Pinto

Department of Biomedical and Translational Sciences Faculty Publications

[Summary] Cardiomyocytes endure physical stress from the myocardium environment while generating their own mechanical strains. The force generated by sarcomeres is transmitted both longitudinally to adjacent sarcomeres and laterally to the cytoskeleton via intermediate filaments. This mechanical stimulus impacts other organelles, including the nucleus, thus playing a vital role in sensing and signaling nuclear adaptations. However, there is limited understanding of how changes in cardiac contractility affect nuclear mechanics. Here, we sought to investigate the effects of hyper- and hypo-contractility in nuclei of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) bearing TNNT2 pathogenic variants associated with hypertrophic (HCM) or dilated …