Enzymes and Coenzymes Commons^™

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, …

Human Kallikrein 2: A Novel Lineage-Specific Surface Target In Prostate Cancer, Fei Shen, Ryan Smith, Theresa Mcdevitt, Krista Menard, Shaozhou Tian, Gerald Chu, Ruchi Chaudhary, Jennifer Mccann, Halley Oyer, Sherry C. Wang, Steven Max, Peter Francis, William K. Kelly, Charles G. Drake

Kimmel Cancer Center Faculty Papers

PURPOSE: Targeted therapies for metastatic prostate cancer are limited, highlighting the need for novel drug targets and mechanisms of action (MoA). Human kallikrein 2 (KLK2) is a prostate-specific antigen expressed across the prostate cancer disease continuum. However, it was not recognized as a therapeutic target for prostate cancer in the past due to limited evidence of its cell surface expression. In this study, we systematically characterized KLK2 expression in prostate cancer, confirmed its cell surface expression, and demonstrated the preclinical efficacy of three KLK2-targeting therapeutics with distinct MoA.

EXPERIMENTAL DESIGN: The KLK2 expression profile in different stages of prostate cancer …

Setdb1 Is Critically Required For Uveal Melanoma Growth And Represents A Promising Therapeutic Target, Imène Krossa, Céline Pisibon, Yann Cheli, Karine Bille, Mélanie Dalmasso, Sabah Hamadat, Chrystel Husser, Marie Irondelle, Julien Cherfils-Vicini, Frédéric Soysouvanh, Sacha Nahon-Esteve, Arnaud Martel, Sandra Lassalle, Jean-Pierre Caujolle, Célia Maschi, Stéphanie Baillif, Dan Hasson, Saul Carcamo, Andrerw E. Aplin, Irwin Davidson, Emily Bernstein, Valeria Naim, Robert Ballotti, Corine Bertolotto, Thomas Strub

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Metastatic uveal melanomas are highly resistant to all existing treatments. To identify actionable vulnerabilities, we conducted a CRISPR-Cas9 knockout screen using a library composed of chromatin regulators. We revealed that the lysine methyltransferase, SETDB1, plays a critical role in metastatic uveal melanoma cell proliferation and survival. Functionally, SETDB1 deficiency induces a DNA damage response, senescence-like state and growth arrest. Knockdown of SETDB1 is associated with a decreased expression of genes related to replication and cell cycle. Moreover, deficiency in CDC6, an essential regulator of DNA replication, phenocopies SETDB1 inhibition. Using a pre-clinical model, we further demonstrated that anti-SETDB1 therapy impairs …

Hydralazine Inhibits Cysteamine Dioxygenase To Treat Preeclampsia And Senesce Glioblastoma, Kyosuke Shishikura, Jiasong Li, Yiming Chen, Nate R. Mcknight, Thomas P. Keeley, Katelyn A. Bustin, Eric W. Barr, Snehil R. Chilkamari, Mahaa Ayub, Sun Woo Kim, Zongtao Lin, Ren-Ming Hu, Kelly Hicks, Xie Wang, Donald M. O'Rourke, J. Martin Bollinger, Zev A. Binder, William H. Parsons, Kirill A. Martemyanov, Aimin Liu, Megan L. Matthews

SKMC Student Presentations and Publications

Hydralazine (HYZ), a treatment for preeclampsia and hypertensive crisis, is listed by the World Health Organization as an essential medicine. Its mode of action has remained unknown through its seven decades of clinical use. Here, we identify 2-aminoethanethiol dioxygenase (ADO), a key mediator of targeted protein degradation, as a selective HYZ target. The drug chelates ADO's metallocofactor and can alkylate one of its ligands. The resultant inactivation stabilizes regulators of G protein signaling (RGS4 and RGS5) that ADO normally marks for proteolysis, explaining the drug's vasodilatory activity and comporting with observations of diminished RGS levels in both clinical preeclampsia and …

Bard1: A Friend Or Foe In Pancreatic Ductal Adenocarcinoma?, Lily Zekavat, Aditi Jain

Department of Surgery Faculty Papers

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive solid malignancy with poor overall prognosis and limited response to standard treatments. Growing interest in the modulation of DNA repair mechanisms, including the homologous recombination (HR) repair pathway, has opened new avenues for therapeutic development. BARD1 (BRCA1-Associated RING Domain 1) plays a complex role in tumor biology, functioning either as a tumor suppressor or as an oncogenic driver, depending on isoform expression, cellular context, and regulatory environment. In this review, we examine the dual roles of BARD1, focusing on its regulation and paradoxical activities in PDAC. We summarize evidence that BARD1 and BARD1 …

The Loss Of Opa1 Accelerates Intervertebral Disc Degeneration And Osteoarthritis In Aged Mice, Vedavathi Madhu, Miriam Hernandaz-Meadows, Ashley Coleman, Kimheak Sao, Kameron Inguito, Owen Haslam, Paige Boneski, Hiromi Sesaki, Ruteja Barve, John Collins, Makarand Risbud

Department of Orthopaedic Surgery Faculty Papers

Recent studies have highlighted the importance of mitochondria in NP cells and articular chondrocyte health. Since the understanding of mechanisms governing mitochondrial dynamics in these tissues is lacking, we investigated the role of OPA1, a mitochondrial fusion protein, in their homeostasis. OPA1 knockdown in NP cells altered mitochondrial size and cristae shape and increased the oxygen consumption rate. OPA1 governed the morphology of multiple organelles, including peroxisomes, early endosomes and cis-Golgi and loss resulted in the dysregulation of autophagy. Metabolic profiling and

Advances In Molecular Imaging Of Vegfrs: Innovations In Imaging And Therapeutics, Hanieh Karimi, Sarah Lee, Wenqi Xu, Sigrid A. Langhans, David K. Johnson, Erik Stauff, Heidi H. Kecskemethy, Lauren W. Averill, Xuyi Yue

Department of Radiology Faculty Papers

Vascular endothelial growth factor receptors (VEGFRs) are key regulators of angiogenesis, lymphangiogenesis, and vascular permeability, playing essential roles in both physiological and pathological processes. The VEGFR family, including VEGFR-1, VEGFR-2, and VEGFR-3, interacts with structurally related VEGF ligands (VEGFA, VEGFB, VEGFC, VEGFD, and placental growth factor [PlGF]), activating downstream signaling pathways that mediate critical cellular processes, including proliferation, migration, and survival. Dysregulation of VEGFR signaling has been implicated in numerous diseases, such as cancer, cardiovascular conditions, and inflammatory disorders. Targeting VEGFRs with radiopharmaceuticals, such as radiolabeled peptides, antibodies, and specific tracers like 64Cu-bevacizumab and 89Zr-ramucirumab, has emerged as a powerful …

Sirt6 Deficiency Promotes Senescence And Age-Associated Intervertebral Disc Degeneration In Mice, Pranay Ramteke, Bahiyah Watson, Mallory Toci, Victoria Tran, Shira N Johnston, Maria Tsingas, Ruteja Barve, Ramkrishna Mitra, Richard Loeser, John Collins, Makarand Risbud

Department of Orthopaedic Surgery Faculty Papers

Intervertebral disc degeneration is a major risk factor contributing to chronic low back and neck pain. While the etiological factors for disc degeneration vary, age is still one of the most important risk factors. Recent studies have shown the promising role of SIRT6 in mammalian aging and skeletal tissue health, however its role in the intervertebral disc health remains unexplored. We investigated the contribution of SIRT6 to disc health by studying the age-dependent spinal phenotype of mice with conditional deletion of Sirt6 in the disc (Acan^CreERT2; Sirt6^fl/fl). Histological studies showed a degenerative phenotype in knockout mice …

Targeting Bard1 Suppresses A Myc-Dependent Transcriptional Program And Tumor Growth In Pancreatic Ductal Adenocarcinoma, Sohum Patel, Eleanor Jenkins, Rutuj P. Kusurkar, Sherry Lee, Wei Jiang, Avinoam Nevler, Matthew Mccoy, Michael J. Pishvaian, Rosalie C. Sears, Jonathan R. Brody, Charles J. Yeo, Aditi Jain

Department of Surgery Faculty Papers

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest cancers demanding better and more effective therapies. BARD1 or BRCA1-Associated -Ring Domain-1 plays a pivotal role in homologous recombination repair (HRR). However, its function and the underlying molecular mechanisms in PDAC are still not fully elucidated. Here, we demonstrate that BARD1 is overexpressed in PDAC and its genetic inhibition suppresses c-Myc and disrupts c-Myc dependent transcriptional program. Mechanistically, BARD1 stabilizes c-Myc through ubiquitin-proteasome system by regulating FBXW7. Importantly, targeting BARD1 using either siRNAs or CRISPR/Cas9 deletion blocks PDAC growth in vitro and in vivo, without any signs of toxicity to mice. …

Nrf2/Cyclooxygenase 2 Signaling In Cr(Vi)-Induced Carcinogenesis, Lei Zhao, Yi-Fang Wang, Andrea Adamcakova-Dodd, Peter Thorne, Ranakul Islam, Ke Jian Liu, Fei Chen, Jia Luo, Ling-Zhi Liu

Kimmel Cancer Center Faculty Papers

Long-term exposure to hexavalent chromium [Cr(VI)] has been linked to lung cancer, and cyclooxygenase-2 (COX-2) is a well-known inflammatory factor. However, the role and mechanism of COX-2 in Cr(VI)-induced carcinogenesis are not clear yet. To address this question, we employed a mouse model exposed to Cr(VI) through intranasal instillation of particulate zinc chromate (ZnCrO4) for 12 weeks. Metabolomics and RNA-seq assays revealed enhanced activity of the arachidonic acid (AA)/eicosanoid metabolism pathway in lung tissues from mice exposed to Cr(VI). COX-2, the key enzyme of the AA/eicosanoid pathway, was significantly upre- gulated in Cr(VI)-exposed lung tissues, as well as in the …

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 …

Cd8Α Structural Domains Enhance Gucy2c Car-T Cell Efficacy, Trevor R. Baybutt, Ariana A. Entezari, Adi Caspi, Ross E. Staudt, Robert D. Carlson, Scott A. Waldman, Adam E. Snook

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Despite success in treating some hematological malignancies, CAR-T cells have not yet produced similar outcomes in solid tumors due, in part, to the tumor microenvironment, poor persistence, and a paucity of suitable target antigens. Importantly, the impact of the CAR components on these challenges remains focused on the intracellular signaling and antigen-binding domains. In contrast, the flexible hinge and transmembrane domains have been commoditized and are the least studied components of the CAR. Here, we compared the hinge and transmembrane domains derived from either the CD8ɑ or CD28 molecule in identical GUCY2C-targeted third-generation designs for colorectal cancer. While these structural …

A Survey Of Oxidative Paracatalytic Reactions Catalyzed By Enzymes That Generate Carbanionic Intermediates: Implications For Ros Production, Cancer Etiology, And Neurodegenerative Diseases, Victoria Bunik, John Schloss, John T. Pinto, Natalia Dudareva, Arthur J L Cooper

NYMC Faculty Publications

Enzymes that generate carbanionic intermediates often catalyze paracatalytic reactions with O2 and other electrophiles not considered “normal” reactants. For example, pyridoxal 5′-phosphate (PLP)—containing pig kidney dopa decarboxylase oxidizes dopamine with molecular O2 to 3,4-dihydroxyphenylacetaldehyde at about 1% of the rate at which it catalyzes nonoxidative dopa decarboxylation. The mutant Y332F enzyme, however, catalyzes stoichiometric conversion of dopa to 3,4-dihydroxyphenylacetaldehyde, suggesting that even minor structural changes may alter or initiate paracatalytic reactions catalyzed by certain enzymes. Carbanions generated by several thiamine diphosphate (ThDP)—dependent enzymes react with different electrophiles, transforming some xenobiotics and endogenous compounds into potentially biologically hazardous products. The detrimental …

Mechanisms Of Oxidant Generation By Catalase, Diane E. Heck, Michael Shakarjian, Hong-Duck Kim, Jeffrey Laskin, Anna M. Vetrano

NYMC Faculty Publications

The enzyme catalase converts solar radiation into reactive oxidant species (ROS). In this study, we report that several bacterial catalases (hydroperoxidases, HP), including Escherichia coli HP-I and HP-II also generate reactive oxidants in response to ultraviolet B light (UVB). HP-I and HP-II are identical except for the presence of NADPH. We found that only one of the catalases, HPI, produces oxidants in response to UVB light, indicating a potential role for the nucleotide in ROS production. This prompts us to speculate that NADPH may act as a cofactor regulating ROS generation by mammalian catalases. Structural analysis of the NADPH domains …