Cell Biology Commons^™

Crosstalk Between Upr And Mitochondria: The Triad Of Er-Mitochondria Contacts, Ca²⁺, And Ros, Ester Zito, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Endoplasmic reticulum (ER) stress is triggered by several cellular perturbations causing protein misfolding, and activates the unfolded protein response (UPR), an initially adaptive signaling network that aims to restore ER and cellular homeostasis. Growing evidence indicates that UPR signaling extends beyond ER proteostasis, influencing mitochondrial function and bioenergetics through ER-mitochondria contact sites (ERMCs). The CHOP-ERO1A-IP3R axis has a primary role in recruiting mitochondria to adaptive UPR. However, its sustained activation renders UPR signaling maladaptive, leading to mitochondrial dysfunction through both outer mitochondrial membrane permeabilization (OMMP) and mitochondrial permeability transition pore (mPTP) opening, ultimately contributing to irreversible cell injury and disease …

Loss Of Mct1 Mediated Lactate Uptake Causes Delayed Endplate Maturation And Intervertebral Disc Degeneration, Maria Tsingas, Konstantinos Tsingas, Mei Smyers, Wujuan Zhang, Aaron R. Goldman, Eulisa Lawrence, John A. Collins, Makarand V. Risbud

Department of Orthopaedic Surgery Faculty Papers

During skeletal growth, it is thought that the lactate secreted by the glycolytic nucleus pulposus (NP) cells exits the intervertebral disc into circulation via endplates. Our current studies challenge this long-held notion. Mice with early postnatal, endplate, and annulus fibrosus-specific deletion of lactate importer, MCT1, exhibited disc degeneration characterized by NP cell loss and pronounced endplate structural changes. Using metabolic and transcriptomic approaches, we demonstrate that MCT1 loss inhibits endplate chondrocyte differentiation and that lactate serves both as a crucial TCA metabolite and promotes protein and histone lactylation and gene expression. These findings suggest that during skeletal growth, NP-derived lactate …

Glycative Stress Disrupts The Mitochondrial-Lysosome Axis And Promotes Geroconversion In Aging Cardiomyocytes, Diana Bou-Teen, Simonas Valiuska, Elisabet Miro-Casas, Chiara Rubeo, Elena Bonzon-Kulichenko, Zuzana Nichtova, Celia Fernandez-Sanz, Javier Inserte, Antonio Rodriguez-Sinovas, Begoña Benito, Eduard Ródenas-Alesina, Jesús Vázquez, Ignacio Ferreira-González, Marisol Ruiz-Meana

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Aging is a major risk factor for heart failure, yet the molecular mechanisms linking cardiac aging to the inflammatory pathophysiology of heart failure remain elusive. Mitochondrial dysfunction and defective organelle quality control are emerging hallmarks of the aging heart, but their biochemical underpinnings are poorly defined. Using comprehensive glycomics, we found that cardiac mitochondria from physiologically aged mice (≥ 20 months) are the major intracellular reservoirs of advanced glycation end products (AGEs), derived primarily from the chemical attack of some α-oxoaldehydes on proteins. This was associated with mild mitochondrial dysfunction and structural remodeling. Lysosomes in aged hearts were enlarged, more …

Stat-Independent Functions Of Janus Kinases 1 And 2 Are Obligatory For The Postnatal Development Of Mammary Epithelial Ducts, Rayane Dennaoui, Madison N. Wicker, Carson Moen, Michaela Schlederer, Kerry Vistisen, Aleata A. Triplett, Thomas Rülicke, Hallgeir Rui, Lukas Kenner, Emilio Casanova, Kay-Uwe Wagner

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Janus kinases 1 and 2 and STAT transcription factors are critical signaling nodes for numerous growth factors. In the mammary gland, JAK2 and STAT5a/b are essential for alveolar cell differentiation and lactation, but little is known about the cooperative roles of JAKs and STATs before pregnancy. We examined female mice conditionally deficient in JAK1/2 and discovered that both kinases jointly regulate epithelial cell proliferation and ductal morphogenesis. To assess the role of downstream STATs, we generated genetic models co-deficient in STAT3/5a/5b with or without STAT1 or JAK1. Although loss of STAT3/5a/5b leads to a JAK1-dependent upregulation of STAT1, the formation …

Elevated Trna Halves In Olfactory Epithelial Cells Of Patients With Schizophrenia, Justin T. Gumas, Megumi Shigematsu, Karin E. Borgmann-Winter, C. G. Hahn, Yohei Kirino

Computational Medicine Center Faculty Papers

Schizophrenia patients' olfactory epithelial cells contain abundant immune-activating tRNA fragments, linking small RNA biology to inflammation and suggesting avenues for diagnostics.

Selective Deletion Of Slc2a1 From The Rpe Reveals That Rods But Not Cones Depend On Glucose Transport Across The Outer Blood-Retinal Barrier, Lauren L. Daniele, John Y.S. Han, Minzhong Yu, Ravi A. Sangani, Craig D. Beight, Cyrus Rostami, Philip D. Kiser, Neal S. Peachy, Nancy J. Philp

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

GLUT1 facilitates a continuous flow of glucose across the inner and outer blood-retinal barriers (BRBs) to support vision. To understand the extent to which photoreceptors rely on glucose transport across the outer BRB, we generated a tamoxifen-inducible conditional knockout of Slc2a1 in the retinal pigment epithelium (RPE) (RPE-iΔGlut1). In the RPE-iΔGlut1 mice, rod photoreceptors exhibited impaired outer segment renewal and decreased the expression of proteins involved in phototransduction and ciliary transport. Proteins regulating the retinal stress response increased. Cone photoreceptors were functional and viable 15 months post-tamoxifen treatment in the RPE-iΔGlut1 mice, while 70% of the rods died. …

Increased Intermembrane Space [Ca2+] Drives Mitochondrial Structural Damage In Cpvt, Shanna Hamilton, Radmila Terentyeva, Roland Veress, Fruzsina Perger, Zuzana Nichtova, Mark Bannister, Jinxi Wang, Sage Quiggle, Rachel Battershell, Matthew Gorr, Sandor Györke, Bum-Rak Choi, Christopher George, Andriy Belevych, György Csordás, Dmitry Terentyev

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Mitochondrial dysfunction caused by abnormally high RyR2 (ryanodine receptor) activity is a common finding in cardiovascular diseases. Mechanisms linking RyR2 gain of function with mitochondrial remodeling remain elusive. We hypothesized that RyR2 hyperactivity in cardiac disease increases [Ca 2+ ] in the mitochondrial intermembrane space (IMS) and activates the Ca 2+ -sensitive protease calpain, driving remodeling of mitochondrial cristae architecture through cleavage of structural protein OPA1 (optic atrophy protein 1).

METHODS: We generated a highly arrhythmogenic rat model of catecholaminergic polymorphic ventricular tachycardia, induced by RyR2 gain-of-function mutation S2236L(Ser2336Leu)(+/-) . We created a new biosensor to measure IMS-[Ca2+ ] …

Protein-Protein Interaction–Interfering Peptide Rescues Dysregulated Nmda Receptor Signaling, Robert E. Featherstone, Hongbin Li, Ameet S. Sengar, Karin E. Borgmann-Winter, Olya Melnychenko, Lindsey M. Crown, Ray L. Gifford, Felix Amirfathi, Anamika Banerjee, Aivi Tran, Krishna Parekh, Margaret Heller, Wenyu Zhang, Robert J. Gallop, Adam D. Marc, Pragya Komal, Michael W. Salter, Steven J. Siegel, Chang-Gyu Hahn

Farber Institute for Neuroscience Faculty Papers

The complex and heterogeneous genetic architecture of neuropsychiatric illnesses compels us to look beyond individual risk genes for therapeutic strategies and target the interactive dynamics and convergence of their protein products. A mechanistic substrate for convergence of synaptic neuropsychiatric risk genes are protein-protein interactions (PPIs) in the N-methyl-D-aspartate receptor (NMDAR) complex. NMDAR hypofunction in schizophrenia is associated with hypoactivity of Src kinase, resulting from convergent alterations in PPIs of Src with its partners. Of these, the association of Src with PSD-95, which inhibits the activity of this kinase in the NMDAR complex, is known to be increased in schizophrenia. Here, …

Er Stress Tolerance Is Regulated By Copper-Dependent Perk Kinase Activity., Sarah E. Bond Newton, Xinglong Shi, Noah R. Beratan, Julia Perhacs, Jitendra K. Arya, Margaret K. Bond, Tali Gidalevitz, Cagla Akay-Espinoza, Donita C. Brady, Kelly L. Jordan-Sciutto

Farber Institute for Neuroscience Faculty Papers

Pancreatic/PKR-like endoplasmic reticulum (ER) kinase (PERK) is a kinase that, in response to ER stress, mediates dual homeostatic and pro-apoptotic signaling. Thus, intricate regulation is required for physiological function. Attempts to modulate PERK activity have shown that the determinants of adaptive vs. maladaptive signaling remain ambiguous. Here, with purified protein, we provide evidence that PERK binds copper, identifies residues required for interaction, and demonstrates that copper is necessary for kinase activity. Furthermore, cellular PERK activity can be modulated via copper availability, and this regulatory relationship can be manipulated to dictate ER stress tolerance. Critically, these phenomena translate to phenotypes in …

Neovascular Pruning By Ido1 Inhibitors Can Potentiate Immunogenic Cytotoxicity Of Ischemia-Targeted Agents To Synergistically Enhance Anti-Pd-1 Responsiveness, Shih-Chun Shen, Souvik Dey, James B. Duhadaway, Erika Sutanto-Ward, Maurice T. Hampton, Serguei V. Kozlov, George C. Prendergast, Alexander J. Muller

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Strategies for deploying indoleamine 2,3-dioxygenase 1 (IDO1)-targeted therapies for use against cancer have focused on IDO1's role in promoting peripheral immune tolerance that shields tumors from effector T cells. However, preclinical investigation of both primary and metastatic tumor development in the lungs has uncovered a previously unappreciated role for IDO1 in directing a counterregulatory response to interferon (IFN)-γ that realigns the local inflammatory environment to promote tumor neovascularization. Understanding how to therapeutically leverage the ability of IDO1 inhibitors to subvert inflammatory neovascularization within the tumor microenvironment has potential ramifications for future clinical development of these compounds.

METHODS: Pulmonary metastases …

Hiv Associated Epigenetic Trends And Chronic Diseases: Insights Into The Hidden Burden Of Chronic Infection, Courtney G. Wallace, Zachary Capriotti, Zachary Klase

Kimmel Cancer Center Faculty Papers

Human Immunodeficiency Virus (HIV) remains a major health challenge despite dramatic advances in treatment and prevention. People living with HIV (PLWH) continue to experience high rates of non-AIDS comorbidities, including cardiovascular, renal, pulmonary, oncologic, and neurocognitive disorders. These conditions persist under viral suppression, underscoring the lasting biological impact of infection. Epigenetic dysregulation has emerged as a key driver of these outcomes. HIV integration, viral proteins, chronic inflammation, and ART exposure have all been reported to alter DNA methylation, histone modifications, transcription factor networks, and noncoding RNA regulation. These changes extend beyond infected cells, reprogramming uninfected immune and tissue compartments. Long-lived …

The C-Terminal Phdvc5hch Tandem Domain Of Nsd2 Is A Combinatorial Reader Of Modified H3k4 And Tri-Methylated H3k27 That Regulates Transcription Of Cell Adhesion Genes In Multiple Myeloma, Andrea Berardi, Charlotte Leonie Kaestner, Michela Ghitti, Giacomo Quilici, Paolo Cocomazzi, Jianping Li, Federico Ballabio, Chiara Zucchelli, Stefan Knapp, Jonathan Licht, Giovanna Musco

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Histone methyltransferase NSD2 (MMSET) overexpression in multiple myeloma (MM) patients plays an important role in the development of this disease subtype. Through the expansion of transcriptional activating H3K36me2 and the suppression of repressive H3K27me3 marks, NSD2 activates an aberrant set of genes that contribute to myeloma growth, adhesive and invasive activities. NSD2 transcriptional activity also depends on its non-catalytic domains, which facilitate its recruitment to chromatin through histone binding. In this study, using NMR, ITC and molecular dynamics simulations, we show that the tandem PHD domain of NSD2 (PHDVC5HCHNSD2) is a combinatorial reader of unmodified histone H3K4 and tri-methylated H3K27 …

Opa1 And Disease-Causing Mutants Perturb Mitochondrial Nucleoid Distribution, J. Macuada, I. Molina-Riquelme, G. Vidal, N. Pérez-Bravo, C. Vásquez-Trincado, G. Aedo, D. Lagos, P. Yu-Wai-Man, R. Horvath, T. J. Rudge, B. Cartes-Saavedra, V. Eisner

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Optic atrophy protein 1 (OPA1) mediates inner mitochondrial membrane (IMM) fusion and cristae organization. Mutations in OPA1 cause autosomal dominant optic atrophy (ADOA), a leading cause of blindness. Cells from ADOA patients show impaired mitochondrial fusion, cristae structure, bioenergetic function, and mitochondrial DNA (mtDNA) integrity. The mtDNA encodes electron transport chain subunits and is packaged into nucleoids spread within the mitochondrial population. Nucleoids interact with the IMM, and their distribution is tightly linked to mitochondrial fusion and cristae shaping. Yet, little is known about the physio-pathological relevance of nucleoid distribution. We studied the effect of OPA1 and ADOA-associated mutants on …

Keratin 17 Is A Prognostic And Predictive Biomarker In Pancreatic Ductal Adenocarcinoma, Lyanne Delgado-Coka, Lucia Roa-Peña, Sruthi Babu, Michael Horowitz, Emanuel Petricoin, Lynn Matrisian, Edik Blais, Natalia Marchenko, Felicia Allard, Ali Akalin, Wei Jiang, Md, Phd, Brent Larson, Andrew Hendifar, Vincent Picozzi, Minsig Choi, Kenneth Shroyer, Luisa Escobar-Hoyos

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

OBJECTIVES: To determine the role of keratin 17 (K17) as a predictive biomarker for response to chemotherapy by defining thresholds of K17 expression based on immunohistochemical tests that could be used to optimize therapeutic intervention for patients with pancreatic ductal adenocarcinoma (PDAC).

METHODS: We profiled K17 expression, a hallmark of the basal molecular subtype of PDAC, by immunohistochemistry in 2 cohorts of formalin-fixed, paraffin-embedded PDACs (n = 305). We determined a K17 threshold of expression to optimize prognostic stratification according to the lowest Akaike information criterion and explored the potential relationship between K17 and chemoresistance by multivariate predictive analyses.

RESULTS: …

Absence Of Motor Impairments Or Pathological Changes In Tmem230 Knockout Rats, Wenjuan Zhang, Hao Peng, Daihe Yang, Guohua Song, Juan He, Yun Zhou, Cao Huang, Bo Huang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Parkinson's disease (PD), which is the second most common neurodegenerative disorder, is characterized by progressive movement impairment and loss of midbrain dopaminergic neurons in the substantia nigra. Although mutations in TMEM230 are linked to familial PD, the pathogenic mechanism underlying TMEM230-associated PD remains to be elucidated. To explore the effect of TMEM230 depletion in vivo, we created TMEM230 knockout rats using CRISPR-Cas9 technology. TMEM230 knockout rats did not exhibit any core features of PD, including impaired motor function, loss of dopaminergic neurons in the substantia nigra, or altered expression of proteins related to autophagy, the Rab family, or vesicular trafficking. …

Neuronal Lrp4 Directs The Development, Maturation And Cytoskeletal Organization Of Drosophila Peripheral Synapses, Alison Depew, Joseph Bruckner, Kate O'Connor-Giles, Timothy Mosca

Student Papers, Posters & Projects

Synaptic development requires multiple signaling pathways to ensure successful connections. Transmembrane receptors are optimally positioned to connect the synapse and the rest of the neuron, often acting as synaptic organizers to synchronize downstream events. One such organizer, the LDL receptor-related protein LRP4, is a cell surface receptor that has been most well-studied postsynaptically at mammalian neuromuscular junctions. Recent work, however, identified emerging roles, but how LRP4 acts as a presynaptic organizer and the downstream mechanisms of LRP4 are not well understood. Here, we show that LRP4 functions presynaptically at Drosophila neuromuscular synapses, acting in motoneurons to instruct pre- and postsynaptic …

Mir-200c Reprograms Fibroblasts To Recapitulate The Phenotype Of Cafs In Breast Cancer Progression, Zhao Lin, Megan Roche, Víctor Díaz-Barros, Marina Domingo-Vidal, Diana Menezes, Madalina Tuluc, Guldeep Uppal, Jaime Caro, Joseph Curry, Ubaldo Martinez-Outshoorn

Kimmel Cancer Center Faculty Papers

Mesenchymal-epithelial plasticity driving cancer progression in cancer-associated fibroblasts (CAFs) is undetermined. This work identifies a subgroup of CAFs in human breast cancer exhibiting mesenchymal-to-epithelial transition (MET) or epithelial-like profile with high miR-200c expression. MiR-200c overexpression in fibroblasts is sufficient to drive breast cancer aggressiveness. Oxidative stress in the tumor microenvironment induces miR-200c by DNA demethylation. Proteomics, RNA-seq and functional analyses reveal that miR-200c is a novel positive regulator of NFκB-HIF signaling via COMMD1 downregulation and stimulates pro-tumorigenic inflammation and glycolysis. Reprogramming fibroblasts toward MET via miR-200c reduces stemness and induces a senescent phenotype. This pro-tumorigenic profile in CAFs fosters carcinoma …

Diversity In The Hla-I Recognition Of Hla-F Monoclonal Antibodies: Hla-F Or Hla-Ib Monospecific, Hla-E Or Hla-G Bispecific Antibodies With Or Without Hla-Ia Reactivity, Mepur Ravindranath, Narendranath Ravindranath, Carly Amato-Menker, Fatiha El Hilali, Edward J Filippone

Division of Nephrology Faculty Papers

Previous investigators have used various anti-HLA-F monoclonal antibodies (mAbs) to demonstrate that the tissue distribution of HLA-F is highly restricted. Notably, these mAbs differed in their immunodiagnostic capabilities. Specifically, mAbs Fpep1.1 and FG1 detected HLA-F intracellularly in B cells but not on the cell surface, whereas mAb 3D11 detected HLA-F on the cell surface. The presence of HLA-F on T cells was recognized by mAb FG1 but not by mAb Fpep1.1. mAb 3D11 detected HLA-F on the cell surface of activated B cells and on peripheral blood lymphocytes, but not on the normal cells. Importantly, mAb 3D11 revealed that HLA-F …

Making The Connection: How Membrane Contact Sites Have Changed Our View Of Organelle Biology, G. Voeltz, E. Sawyer, G. Hajnóczky, W. Prinz

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The view of organelles and how they operate together has changed dramatically over the last two decades. The textbook view of organelles was that they operated largely independently and were connected by vesicular trafficking and the diffusion of signals through the cytoplasm. We now know that all organelles make functional close contacts with one another, often called membrane contact sites. The study of these sites has moved to center stage in cell biology as it has become clear that they play critical roles in healthy and developing cells and during cell stress and disease states. Contact sites have important roles …

Examining Pi3k-Signaling-Dependent Regulation Of Lens Organelle Free Zone Formation Via Immunolocalization And Immunoblotting In Chick Embryos, Rifah Gheyas, A. Sue Menko

Computational Medicine Center Faculty Papers

The elimination of lens organelles during development, required for mature lens function, is an autophagy-dependent mechanism induced through suppression of PI3K signaling. Here, we present a protocol for investigating the signaling pathways responsible for induction of the formation of this lens organelle free zone. We describe steps for preparation of lens organ culture and use of signaling pathway inhibitors. We then detail procedures for analyzing their impact using both confocal microscopy imaging of immunolabeled lens cryosections and immunoblot approaches. For complete details on the use and execution of this protocol, please refer to Gheyas et al. (2022).

Fibrosis-The Tale Of H3k27 Histone Methyltransferases And Demethylases, Morgan D. Basta, Svetlana Petruk, Alexander Mazo, Janice L. Walker

Department of Biochemistry and Molecular Biology Faculty Papers

Fibrosis, or excessive scarring, is characterized by the emergence of alpha-smooth muscle actin (αSMA)-expressing myofibroblasts and the excessive accumulation of fibrotic extracellular matrix (ECM). Currently, there is a lack of effective treatment options for fibrosis, highlighting an unmet need to identify new therapeutic targets. The acquisition of a fibrotic phenotype is associated with changes in chromatin structure, a key determinant of gene transcription activation and repression. The major repressive histone mark, H3K27me3, has been linked to dynamic changes in gene expression in fibrosis through alterations in chromatin structure. H3K27-specific homologous histone methylase (HMT) enzymes, Enhancer of zeste 1 and 2 …

Enhancement Of Tki Sensitivity In Lung Adenocarcinoma Through M6a-Dependent Translational Repression Of Wnt Signaling By Circ-Fbxw7, Kai Li, Zi-Yang Peng, Rui Wang, Xiang Li, Ning Du, Da-Peng Liu, Jia Zhang, Yun-Feng Zhang, Lei Ma, Ye Sun, Shou-Ching Tang, Hong Ren, Yi-Ping Yang, Xin Sun

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Tyrosine kinase inhibitors (TKIs) that specifically target mutational points in the EGFR gene have significantly reduced suffering and provided greater relief to patients with lung adenocarcinoma (LUAD). The third-generation EGFR-TKI, Osimertinib, has been successfully employed in clinical treatments to overcome resistance to both original and acquired T790M and L858R mutational points. Nevertheless, the issue of treatment failure response has emerged as an insurmountable problem.

METHODS: By employing a combination of multiple and integrated approaches, we successfully identified a distinct population within the tumor group that plays a significant role in carcinogenesis, resistance, and recurrence. Our research suggests that addressing …

Zinc Treatment Reverses And Anti-Zn-Regulated Mirs Suppress Esophageal Carcinomas In Vivo, Louise Fong, Kay Huebner, Ruiyan Jing, Karl Smalley, Christopher R Brydges, Oliver Fiehn, John Farber, Carlo M Croce

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Esophageal squamous cell carcinoma (ESCC) is a deadly disease with few prevention or treatment options. ESCC development in humans and rodents is associated with Zn deficiency (ZD), inflammation, and overexpression of oncogenic microRNAs: miR-31 and miR-21. In a ZD-promoted ESCC rat model with upregulation of these miRs, systemic antimiR-31 suppresses the miR-31-EGLN3/STK40-NF-κB-controlled inflammatory pathway and ESCC. In this model, systemic delivery of Zn-regulated antimiR-31, followed by antimiR-21, restored expression of tumor-suppressor proteins targeted by these specific miRs: STK40/EGLN3 (miR-31), PDCD4 (miR-21), suppressing inflammation, promoting apoptosis, and inhibiting ESCC development. Moreover, ESCC-bearing Zn-deficient (ZD) rats receiving Zn medication showed a 47% …

Dysregulation Of Ryr Calcium Channel Causes The Onset Of Mitochondrial Retrograde Signaling, Anindya Roy Chowdhury, Satish Srinivasan, György Csordás, György Hajnóczky, Narayan G Avadhani

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

This study shows that multiple modes of mitochondrial stress generated by partial mtDNA depletion or cytochrome c oxidase disruption cause ryanodine receptor channel (RyR) dysregulation, which instigates the release of Ca2+ in the cytoplasm of C2C12 myoblasts and HCT116 carcinoma cells. We also observed a reciprocal downregulation of IP3R channel activity and reduced mitochondrial uptake of Ca2+. Ryanodine, an RyR antagonist, abrogated the mitochondrial stress-mediated increase in [Ca2+]c and the entire downstream signaling cascades of mitochondrial retrograde signaling. Interestingly, ryanodine also inhibited mitochondrial stress-induced invasive behavior in mtDNA-depleted C2C12 cells and HCT116 carcinoma cells. In addition, co-immunoprecipitation shows reduced FKBP12 …

Phosphorylation Of Cyclophilin D At Serine 191 Regulates Mitochondrial Permeability Transition Pore Opening And Cell Death After Ischemia-Reperfusion, Stephen Hurst, Fabrice Gonnot, Maya Dia, Claire Crola Da Silva, Ludovic Gomez, Shey-Shing Sheu

Department of Medicine Faculty Papers

The mitochondrial permeability transition pore (mPTP) plays a critical role in the pathogenesis of cardiovascular diseases, including ischemia/reperfusion injury. Although the pore structure is still unresolved, the mechanism through which cyclophilin D (CypD) regulates mPTP opening is the subject of intensive studies. While post-translational modifications of CypD have been shown to modulate pore opening, specific phosphorylation sites of CypD have not yet been identified. We hypothesized here that phosphorylation of CypD on a serine residue controls mPTP opening and subsequent cell death at reperfusion. We combined in silico analysis with in vitro and genetic manipulations to determine potential CypD phosphorylation …

Microrna And Transcription Factor Co-Regulatory Networks And Subtype Classification Of Seminoma And Non-Seminoma In Testicular Germ Cell Tumors, Guimin Qin, Saurav Mallik, Ramkrishna Mitra, Aimin Li, Peilin Jia, Christine M. Eischen, Zhongming Zhao

Department of Cancer Biology Faculty Papers

Recent studies have revealed that feed-forward loops (FFLs) as regulatory motifs have synergistic roles in cellular systems and their disruption may cause diseases including cancer. FFLs may include two regulators such as transcription factors (TFs) and microRNAs (miRNAs). In this study, we extensively investigated TF and miRNA regulation pairs, their FFLs, and TF-miRNA mediated regulatory networks in two major types of testicular germ cell tumors (TGCT): seminoma (SE) and non-seminoma (NSE). Specifically, we identified differentially expressed mRNA genes and miRNAs in 103 tumors using the transcriptomic data from The Cancer Genome Atlas. Next, we determined significantly correlated TF-gene/miRNA and miRNA-gene/TF …

Decorin As A Multivalent Therapeutic Agent Against Cancer., Thomas Neill, Liliana Schaefer, Renato V. Iozzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Decorin is a prototypical small leucine-rich proteoglycan that epitomizes the multifunctional nature of this critical gene family. Soluble decorin engages multiple receptor tyrosine kinases within the target-rich environment of the tumor stroma and tumor parenchyma. Upon receptor binding, decorin initiates signaling pathways within endothelial cells downstream of VEGFR2 that ultimately culminate in a Peg3/Beclin 1/LC3-dependent autophagic program. Concomitant with autophagic induction, decorin blunts capillary morphogenesis and endothelial cell migration, thereby significantly compromising tumor angiogenesis. In parallel within the tumor proper, decorin binds multiple RTKs with high affinity, including Met, for a multitude of oncosuppressive functions including growth inhibition, tumor cell …

Nuclear Localization Of Cpi-17, A Protein Phosphatase-1 Inhibitor Protein, Affects Histone H3 Phosphorylation And Corresponds To Proliferation Of Cancer And Smooth Muscle Cells., Masumi Eto, Jason A Kirkbride, Rishika Chugh, Nana Kofi Karikari, Jee In Kim

Department of Molecular Physiology and Biophysics Faculty Papers

CPI-17 (C-kinase-activated protein phosphatase-1 (PP1) inhibitor, 17kDa) is a cytoplasmic protein predominantly expressed in mature smooth muscle (SM) that regulates the myosin-associated PP1 holoenzyme (MLCP). Here, we show CPI-17 expression in proliferating cells, such as pancreatic cancer and hyperplastic SM cells. Immunofluorescence showed that CPI-17 was concentrated in nuclei of human pancreatic cancer (Panc1) cells. Nuclear accumulation of CPI-17 was also detected in the proliferating vascular SM cell culture and cells at neointima of rat vascular injury model. The N-terminal 21-residue tail domain of CPI-17 was necessary for the nuclear localization. Phospho-mimetic Asp-substitution of CPI-17 at Ser12 attenuated the nuclear …

Endogenous Inhibitor Proteins That Connect Ser/Thr Kinases And Phosphatases In Cell Signaling., Masumi Eto, David L Brautigan

Department of Molecular Physiology and Biophysics Faculty Papers

Protein phosphatase activity acts as a primary determinant of the extent and duration of phosphorylation of cellular proteins in response to physiological stimuli. Ser/Thr protein phosphatase-1 (PP1) belongs to the PPP superfamily, and is associated with regulatory subunits that confer substrate specificity, allosteric regulation, and subcellular compartmentalization. In addition, all eukaryotic cells contain multiple heat-stable proteins that originally were thought to inhibit phosphatase catalytic subunits released from the regulatory subunits, as a fail-safe mechanism. However, discovery of C-kinase-activated PP1 inhibitor, Mr of 17 kDa (CPI-17) required fresh thinking about the endogenous inhibitors as specific regulators of particular phosphatase complexes, acting …