Cell and Developmental Biology Commons^™

Steroid Receptors And Coregulators: Dissemination Of Sex Differences And Emerging Technologies, Sally Pauss, Evelyn A. Bates, Genesee J. Martinez, Zane T. Bates, Zachary A. Kipp, Cassandra D. Gipson, Terry D. Hinds Jr.

Markey Cancer Center Faculty Publications

Steroid receptors are ligand-induced transcription factors that have broad functions among all living animal species, ranging from control of sex differences, body weight, stress responses, and many others. Their binding to coregulator proteins is regulated by corepressors and coactivators that interchange upon stimulation with a ligand. Coregulator proteins are an imperative and understudied aspect of steroid receptor signaling. Here, we discuss steroid receptor basics from protein domain structures that allow them to interact with coregulators and other proteins, their essential functions as transcription factors, and other elemental protein–protein interactions. We deliberate about the mechanisms that coregulators control in steroid receptor …

Artesunate Enhances The Efficacy Of Enzalutamide In Advanced Prostate Cancer, Xinyi Wang, Jinghui Liu, Fengyi Mao, Yifan Kong, Qiongsi Zhang, Chaohao Li, Daheng He, Chi Wang, Yanquan Zhang, Ruixin Wang, Sally R. Ellingson, Qiou Wei, Zhiguo Li, Xiaoqi Liu

Markey Cancer Center Faculty Publications

Prostate cancer (PCa) is one of the leading causes of death among men worldwide. Treatments targeting the androgen receptor pathway remain the standard therapy for PCa patients. Enzalutamide (ENZ), a second-generation androgen receptor inhibitor, was developed to treat castration-resistant prostate cancer. However, while patients initially respond to ENZ, drug resistance typically develops within a few months. Artesunate (ART), a semisynthetic derivative of the Artemisinin plant, is approved for antimalaria treatment. In this study, we conducted an FDA-approved drug screening and identified ART as a potential candidate for overcoming ENZ resistance in PCa. Mechanistically, ART induces the degradation of c-Myc, enhancing …

Staying Sane In The Membrane: Neutral Sphingomyelinase 2 As A Master Regulator Of Plasma Membrane Ceramide, Zainuddin Quadri, Erhard Bieberich

Markey Cancer Center Faculty Publications

Ceramide, a key signaling sphingolipid in the plasma membrane, plays a pivotal role in fundamental cellular processes such as adhesion, polarity, and programmed cell death. The generation of plasma membrane ceramide is largely attributed to the activity of two types of sphingomyelinases: neutral sphingomyelinase 2 (nSMase2, Smpd3) and acid sphingomyelinase (aSMase, Smpd1). While many studies have explored ceramide generation following experimental activation of these enzymes, the mechanisms governing basal or steady- state ceramide levels have remained poorly understood. Using an innovative mass spectrometry approach developed in the Canals’ lab, the team has quantified the distinct contributions of nSMase2 and aSMase …

Pharmacological Or Genetic Inhibition Of Ltcc Promotes Cardiomyocyte Proliferation Through Inhibition Of Calcineurin Activity, Lynn A. C. Devilée, Abou Bakr M. Salama, Jessica M. Miller, Janice D. Reid, Qinghui Ou, Nourhan M. Baraka, Kamal Abou Farraj, Madiha Jamal, Yibing Nong, Todd K. Rosengart, Douglas A. Andres, Jonathan Satin, Tamer M. A. Mohamed, James E. Hudson, Riham R. E. Abouleisa

Markey Cancer Center Faculty Publications

Cardiomyocytes (CMs) lost during ischemic cardiac injury cannot be replaced due to their limited proliferative capacity. Calcium is an important signal transducer that regulates key cellular processes, but its role in regulating CM proliferation is incompletely understood. Here we show a robust pathway for new calcium signaling-based cardiac regenerative strategies. A drug screen targeting proteins involved in CM calcium cycling in human embryonic stem cell-derived cardiac organoids (hCOs) revealed that only the inhibition of L-Type Calcium Channel (LTCC) induced the CM cell cycle. Furthermore, overexpression of Ras-related associated with Diabetes (RRAD), an endogenous inhibitor of LTCC, induced CM cell cycle …

Mir-27a-3p Regulates Intestinal Cell Proliferation And Differentiation Through Wnt/Β-Catenin Signalling, Chang Li, Yuning Zhou, Yinping Jiang, Zhijie Yin, Heidi L. Weiss, Qingding Wang, B. Mark Evers

Markey Cancer Center Faculty Publications

Intestinal stem cells differentiate into absorptive enterocytes, characterised by increased brush border enzymes such as intestinal alkaline phosphatase (IAP), making up the majority (95%) of the terminally differentiated cells in the villus. Loss of integrity of the intestinal epithelium plays a key role in inflammatory diseases and gastrointestinal infection. Here, we show that the intestinal microRNA (miR)-27a-3p is an important regulator of intestinal epithelial cell proliferation and enterocyte differentiation. Repression of endogenous miR-27a-3p leads to increased enterocyte differentiation and decreased intestinal epithelial cell proliferation in mouse and human small intestinal organoids. Mechanistically, miR-27a-3p regulates intestinal cell differentiation and proliferation at …

Conditional Deletion Of Ceacam1 In Hepatic Stellate Cells Causes Their Activation, Harrison T. Muturi, Hilda E. Ghadieh, Suman Asalla, Sumona G. Lester, Getachew D. Belew, Sobia Zaidi, Raziyeh Abdolahipour, Abhishek P. Shrestha, Agnes O. Portuphy, Hannah L. Stankus, Raghd Abu Helal, Stefaan Verhulst, Sergio Duarte, Ali Zarrinpar, Leo A. Van Grunsven, Scott L. Friedman, Robert F. Schwabe, Terry D. Hinds, Jr., Sivarajan Kumarasamy, Sonia M. Najjar

Markey Cancer Center Faculty Publications

Objectives: Hepatic CEACAM1 expression declines with advanced hepatic fibrosis stage in patients with metabolic dysfunction-associated steatohepatitis (MASH). Global and hepatocyte-specific deletions of Ceacam1 impair insulin clearance to cause hepatic insulin resistance and steatosis. They also cause hepatic inflammation and fibrosis, a condition characterized by excessive collagen production from activated hepatic stellate cells (HSCs). Given the positive effect of PPARg on CEACAM1 transcription and on HSCs quiescence, the current studies investigated whether CEACAM1 loss from HSCs causes their activation.

Methods: We examined whether lentiviral shRNA-mediated CEACAM1 donwregulation (KD-LX2) activates cultured human LX2 stellate cells. We also generated LratCre þ Cc1fl/fl mutants …

Novel Psychoplastogen Dm506 Reduces Cue-Induced Heroin-Seeking And Inhibits Tonic Gaba Currents In The Prelimbic Cortex, Kassandra Looschen, Shailesh N. Khatri, Malabika Maulik, Colin Salisbury, Alaina F. Carman, Katilyn Corriveau, Colton Smith, Dina Manetti, Maria Novella Romanelli, Hugo R. Arias, Cassandra D. Gipson, Swarup Mitra

Markey Cancer Center Faculty Publications

Opioid use disorder is a major public health crisis that is manifested by persistent drug-seeking behavior and high relapse frequency. Most of the available treatments rely on targeting opioid receptors using small molecules that do not provide sustained symptom alleviation. Psychoplastogens are a novel class of non-opioid drugs that produce rapid and sustained effects on neuronal plasticity, intended to produce therapeutic benefits. Ibogalogs are synthetic derivatives of iboga alkaloids that lack hallucinogenic or adverse side effects. In the current study, we examine the therapeutic potential of DM506, a novel ibogalog lacking any cardiotoxic or hallucinogenic effects, in cue-induced seeking behavior …

Ceramide-Mediated Orchestration Of Oxidative Stress Response Through Filopodia-Derived Small Extracellular Vesicles, Zainuddin Quadri, Ahmed Elsherbini, Simone M. Crivelli, Salim S. El-Amouri, Priyanka Tripathi, Zhihui Zhu, Xiaojia Ren, Liping Zhang, Stefka D. Spassieva, Mariana N. Nikolova‑Karakashian, Erhard Bieberich

Markey Cancer Center Faculty Publications

Extracellular vesicles (EVs) are shed from the plasma membrane, but the regulation and function of these EVs remain unclear. We found that oxidative stress induced by H 2 O 2 in Hela cells stimulated filopodia formation and the secretion of EVs. EVs were small (150 nm) and labeled for CD44, indicating that they were derived from filopodia. Filopodia-derived small EVs (sEVs) were enriched with the sphingolipid ceramide, consistent with increased ceramide in the plasma membrane of filopo- dia. Ceramide was colocalized with neutral sphingomyelinase 2 (nSMase2) and acid sphingomyelinase (ASM), two sphingomyelinases generating ceramide at the plasma membrane. Inhibition of …

Soxb1 Transcription Factors Are Essential For Initiating And Maintaining Neural Plate Border Gene Expression, Elizabeth Schock, Joshua R. York, Austin P. Li, Ashlyn Y. Tu, Carole Labonne

Markey Cancer Center Faculty Publications

SoxB1 transcription factors (Sox2/3) are well known for their role in early neural fate specification in the embryo, but little is known about functional roles for SoxB1 factors in non-neural ectodermal cell types, such as the neural plate border (NPB). Using Xenopus laevis, we set out to determine whether SoxB1 transcription factors have a regulatory function in NPB formation. Here, we show that SoxB1 factors are necessary for NPB formation, and that prolonged SoxB1 factor activity blocks the transition from a NPB to a neural crest state. Using ChIP-seq, we demonstrate that Sox3 is enriched upstream of NPB genes in …

A Probabilistic Approach To Estimate The Temporal Order Of Pathway Mutations Accounting For Intra-Tumor Heterogeneity, Menghan Wang, Yanqi Xie, Jinpeng Liu, Austin Li, Li Chen, Arnold Stromberg, Susanne Arnold, Chunming Liu, Chi Wang

Markey Cancer Center Faculty Publications

The development of cancer involves the accumulation of somatic mutations in several essential biological pathways. Delineating the temporal order of pathway mutations during tumori- genesis is crucial for comprehending the biological mechanisms underlying cancer development and identifying potential targets for therapeutic intervention. Several computational and statistical methods have been introduced for estimating the order of somatic mutations based on mutation profile data from a cohort of patients. However, one major issue of current methods is that they do not take into account intra-tumor heterogeneity (ITH), which limits their ability to accurately discern the order of pathway mutations. To address this …

Protein Oxidation In Aging And Alzheimer’S Disease Brain, Rukhsana Sultana, D. Allan Butterfield

Markey Cancer Center Faculty Publications

Proteins are essential molecules that play crucial roles in maintaining cellular homeostasis and carrying out biological functions such as catalyzing biochemical reactions, structural proteins, immune response, etc. However, proteins also are highly susceptible to damage by reactive oxygen species (ROS) and reactive nitrogen species (RNS). In this review, we summarize the role of protein oxidation in normal aging and Alzheimer’s disease (AD). The major emphasis of this review article is on the carbonylation and nitration of proteins in AD and mild cognitive impairment (MCI). The oxidatively modified proteins showed a strong correlation with the reported changes in brain structure, carbohydrate …

Zebrafish Drug Screening Identifies Erlotinib As An Inhibitor Of Wnt/ Β-Catenin Signaling And Self-Renewal In T-Cell Acute Lymphoblastic Leukemia, Majd A. Al-Hamaly, Anna H. Cox, Meghan G. Haney, Wen Zhang, Emma C. Arvin, Shilpa Sampathi, Mary Wimsett, Chunming Liu, Jessica S. Blackburn

Markey Cancer Center Faculty Publications

The Wnt/β-catenin pathway’s significance in cancer initiation, progression, and stem cell biology underscores its therapeutic potential. However, the clinical application of Wnt inhibitors remains limited due to challenges posed by off-target effects and complex cross-talk of Wnt signaling with other pathways. In this study, we leveraged a zebrafish model to perform a robust and rapid drug screening of 773 FDA-approved compounds to identify Wnt/β-catenin inhibitors with minimal toxicity. Utilizing zebrafish expressing a Wnt reporter, we identified several drugs that suppressed Wnt signaling without compromising zebrafish development. The effi- cacy of the top hit, Erlotinib, extended to human cells, where it …

The Carboxy Terminus Causes Interfacial Assembly Of Oleate Hydratase On A Membrane Bilayer, Christopher D. Radka, Christy R. Grace, Hale S. Hasdemir, Yupeng Li, Carlos C. Rodriguez, Patrick Rodrigues, Michael L. Oldham, M. Zuhaib Qayyum, Aaron Pitre, William J. Maccain, Ravi C. Kalathur, Emad Tajkhorshid, Charles O. Rock

Markey Cancer Center Faculty Publications

The soluble flavoprotein oleate hydratase (OhyA) hydrates the 9-cis double bond of unsaturated fatty acids. OhyA sub- strates are embedded in membrane bilayers; OhyA must remove the fatty acid from the bilayer and enclose it in the active site. Here, we show that the positively charged helix- turn-helix motif in the carboxy terminus (CTD) is responsible for interacting with the negatively charged phosphatidylgly- cerol (PG) bilayer. Super-resolution microscopy of Staphylo- coccus aureus cells expressing green fluorescent protein fused to OhyA or the CTD sequence shows subcellular localization along the cellular boundary, indicating OhyA is membrane- associated and the CTD sequence …

Elevated Free Cholesterol Levels Due To Impaired Reverse Cholesterol Transport Are A Risk Factor For Polymicrobial Sepsis In Mice, Qian Wang, Ling Guo, Dan Hao, Misa Ito, Chieko Mineo, Philip W. Shaul, Xiang-An Li

Markey Cancer Center Faculty Publications

Dysregulated lipid metabolism is commonly observed in septic patients, but how it contributes to sepsis remains largely unknown. Reverse cholesterol transport (RCT) is crucial for regulating cholesterol metabolism in circulation. During RCT, high-density lipoprotein collects cholesterol from peripheral tissues and transports it to the liver’s scavenger receptor BI (SR- BI), where SR-BI mediates the uptake of cholesteryl esters (CEs) from high-density lipoprotein for excretion via bile. In this study, we utilized AlbCreSR-BIfl/fl mice, a model with impaired RCT, to investigate the impact of RCT on sepsis. We found that AlbCreSR-BIfl/fl mice were significantly more susceptible to cecal ligation and puncture …

Nudcl2 Is Required For Cytokinesis By Stabilizing Rcc2 With Hsp90 At The Midbody, Xiaoyang Xu, Yuliang Huang, Feng Yang, Xiaoxia Sun, Rijin Lin, Jiaxing Feng, Mingyang Yang, Jiaqi Shao, Xiaoqi Liu, Tianhua Zhou, Shanshan Xie, Yuehong Yang

Markey Cancer Center Faculty Publications

Cytokinesis is required for faithful division of cytoplasmic components and duplicated nuclei into two daughter cells. Midbody, a protein-dense organelle that forms at the intercellular bridge, is indispensable for success- ful cytokinesis. However, the regulatory mechanism of cytokinesis at the midbody still remains elusive. Here, we unveil a critical role for NudC-like protein 2 (NudCL2), a co-chaperone of heat shock protein 90 (Hsp90), in cytokinesis regulation by stabilizing regulator of chromosome condensation 2 (RCC2) at the midbody in mam- malian cells. NudCL2 localizes at the midbody, and its downregulation results in cytokinesis failure, multinu- cleation, and midbody disorganization. Using iTRAQ-based …

Pai-1 As A Critical Factor In The Resolution Of Sepsis And Acute Kidney Injury In Old Age, Maria E. C. Bruno, Sujata Mukherjee, Jamie L. Sturgill, Virgilius Cornea, Peng Yeh, Gregory S. Hawk, Hiroshi Saito, Marlene E. Starr

Markey Cancer Center Faculty Publications

Elevated plasma levels of plasminogen activator inhibitor type 1 (PAI-1) are documented in patients with sepsis and levels positively correlate with disease severity and mortality. Our prior work demonstrated that PAI-1 in plasma is positively associated with acute kidney injury (AKI) in septic patients and mice. The objective of this study was to determine if PAI-1 is causally related to AKI and worse sepsis outcomes using a clinically-relevant and age-appropriate murine model of sepsis. Sepsis was induced by cecal slurry (CS)-injection to wild-type (WT, C57BL/6) and PAI-1 knockout (KO) mice at young (5–9 months) and old (18–22 months) age. Survival …

Structure, Dynamics, And Redox Reactivity Of An All-Purpose Flavodoxin, Sharique Khan, Ahmadullah Ansari, Monica Brachi, Debarati Das, Wassim El Housseini, Shelley Minteer, Anne-Francis Miller

Markey Cancer Center Faculty Publications

The flavodoxin of Rhodopseudomonas palustris CGA009 (Rp9Fld) supplies highly reducing equivalents to crucial en- zymes such as hydrogenase, especially when the organism is iron-restricted. By acquiring those electrons from photodriven electron flow via the bifurcating electron transfer flavoprotein, Rp9Fld provides solar power to vital metabolic processes. To understand Rp9Fld’s ability to work with diverse partners, we solved its crystal structure. We observed the canonical fla- vodoxin (Fld) fold and features common to other long-chain Flds but not all the surface loops thought to recognize part- ner proteins. Moreover, some of the loops display alternative structures and dynamics. To advance studies …

Non-Transcriptional Irf7 Interacts With Nf-Κb To Inhibit Viral Inflammation, Shumin Fan, Sonam Popli, Sukanya Chakravarty, Ritu Chakravarty, Saurabh Chattopadhyay

Markey Cancer Center Faculty Publications

Interferon (IFN) regulatory factors (IRF) are key transcrip- tion factors in cellular antiviral responses. IRF7, a virus- inducible IRF, expressed primarily in myeloid cells, is required for transcriptional induction of interferon α and antiviral genes. IRF7 is activated by virus-induced phosphory- lation in the cytoplasm, leading to its translocation to the nu- cleus for transcriptional activity. Here, we revealed a nontranscriptional activity of IRF7 contributing to its antiviral functions. IRF7 interacted with the pro-inflammatory tran- scription factor NF-κB-p65 and inhibited the induction of in- flammatory target genes. Using knockdown, knockout, and overexpression strategies, we demonstrated that IRF7 inhibited NF-κB–dependent inflammatory …

Foxs1 Is Increased In Liver Fibrosis And Regulates Tgfβ Responsiveness And Proliferation Pathways In Human Hepatic Stellate Cells, Evelyn A. Bates, Zachary A. Kipp, Wang-Hsin Lee, Genesee J. Martinez, Lauren Weaver, Kathryn N. Becker, Sally Pauss, Justin F. Creeden, Garrett B. Anspach, Robert N. Helsley, Mei Xu, Maria E. C. Bruno, Marlene E. Starr, Terry D. Hinds Jr.

Markey Cancer Center Faculty Publications

Liver fibrosis commences with liver injury stimulating transforming growth factor beta (TGFβ) activation of hepatic stellate cells (HSCs), causing scarring and irreversible damage. TGFβ induces expression of the transcription factor Forkhead box S1 (FOXS1) in hepatocytes and may have a role in the pathogenesis of hepatocellular carcinoma (HCC). To date, no studies have determined how it affects HSCs. We analyzed human livers with cirrhosis, HCC, and a murine fibrosis model and found that FOXS1 expression is significantly higher in fibrotic livers but not in HCC. Next, we treated human LX2 HSC cells with TGFβ to activate fibrotic pathways, and FOXS1 …

Mir-27a-3p Regulates Intestinal Cell Proliferation And Differentiation Through Wnt/Β-Catenin Signalling, Chang Li, Yuning Zhou, Yinping Jiang, Zhijie Yin, Heidi L. Weiss, Qingding Wang, B. Mark Evers

Markey Cancer Center Faculty Publications

Intestinal stem cells differentiate into absorptive enterocytes, characterised by increased brush border enzymes such as intestinal alkaline phosphatase (IAP), making up the majority (95%) of the terminally differentiated cells in the villus. Loss of integ- rity of the intestinal epithelium plays a key role in inflammatory diseases and gastro- intestinal infection. Here, we show that the intestinal microRNA (miR)-27a-3p is an important regulator of intestinal epithelial cell proliferation and enterocyte differenti- ation. Repression of endogenous miR-27a-3p leads to increased enterocyte differen- tiation and decreased intestinal epithelial cell proliferation in mouse and human small intestinal organoids. Mechanistically, miR-27a-3p regulates intestinal cell …

Cell Aggregation Activates Small Gtpase Rac1 And Induces Cd44 Cleavage By Maintaining Lipid Raft Integrity, Dong Li, Younhee Park, Hami Hemati, Xia Liu

Markey Cancer Center Faculty Publications

Lipid rafts are highly ordered membrane domains that are enriched in cholesterol and glycosphingolipids and serve as major platforms for signal transduction. Cell detachment from the extracellular matrix (ECM) triggers lipid raft disruption and anoikis, which is a barrier for cancer cells to metastasize. Compared to single circulating tumor cells (CTCs), our recent studies have demonstrated that CD44-mediatd cell aggregation enhances the stemness, survival and metastatic ability of aggregated cells. Here, we investigated whether and how lipid rafts are involved in CD44-mediated cell aggregation. We found that cell detachment, which mimics the condition when tumor cells detach from the ECM …

Cyclin D1 Extensively Reprograms Metabolism To Support Biosynthetic Pathways In Hepatocytes, Heng Wu, Betsy T. Kren, Andrew N. Lane, Teresa A. Cassel, Richard M. Higashi, Teresa Whei-Mei Fan, George S. Scaria, Laurie L. Shekels, Mark A. Klein, Jeffrey H. Albrecht

Markey Cancer Center Faculty Publications

Cell proliferation requires metabolic reprogramming to accommodate biosynthesis of new cell components, and similar alterations occur in cancer cells. However, the mechanisms linking the cell cycle machinery to metabolism are not well defined. Cyclin D1, along with its main partner cyclindependent kinase 4 (Cdk4), is a pivotal cell cycle regulator and driver oncogene that is overexpressed in many cancers. Here, we examine hepatocyte proliferation to define novel effects of cyclin D1 on biosynthetic metabolism. Metabolomic studies reveal that cyclin D1 broadly promotes biosynthetic pathways including glycolysis, the pentose phosphate pathway, and the purine and pyrimidine nucleotide synthesis in hepatocytes. Proteomic …

Distinct Camp Signaling Microdomains Differentially Regulate Melanosomal Ph And Pigmentation, Maftuna Yusupova, Dalee Zhou, Jaewon You, Jeydi Gonzalez-Guzman, Megha B. Ghanta, Hong Pu, Zalfa Abdel-Malek, Qiuying Chen, Steven S. Gross, John August D'Orazio, Shosuke Ito, Kazumasa Wakamatsu, Melissa L. Harris, Jonathan H. Zippin

Markey Cancer Center Faculty Publications

cAMP signaling is a well-established regulator of melanin synthesis. Two distinct cAMP signaling pathways—the transmembrane adenylyl cyclase pathway, activated primarily by the MC1R, and the soluble adenylyl cyclase (sAC) pathway—affect melanin synthesis. The sAC pathway affects melanin synthesis by regulating melanosomal pH, and the MC1R pathway affects melanin synthesis by regulating gene expression and post-translational modifications. However, whether MC1R genotype affects melanosomal pH is poorly understood. We now report that loss of function MC1R does not affect melanosomal pH. Thus, sAC signaling appears to be the only cAMP signaling pathway that regulates melanosomal pH. We also addressed whether MC1R genotype …

Inhibition Of Mitochondrial Fission Activates Glycogen Synthesis To Support Cell Survival In Colon Cancer, Sumati Raj Hasani, Lyndsay E. A. Young, Warren Van Nort, Moumita Banerjee, Dylan R. Rivas, Jinhwan Kim, Xiaopeng Xiong, Ramon C. Sun, Matthew S. Gentry, Hiromi Sesaki, Tianyan Gao

Markey Cancer Center Faculty Publications

Metabolic reprogramming has been recognized as one of the major mechanisms that fuel tumor initiation and progression. Our previous studies demonstrate that activation of Drp1 promotes fatty acid oxidation and downstream Wnt signaling. Here we investigate the role of Drp1 in regulating glycogen metabolism in colon cancer. Knockdown of Drp1 decreases mitochondrial respiration without increasing glycolysis. Analysis of cellular metabolites reveals that the levels of glucose-6-phosphate, a precursor for glycogenesis, are significantly elevated whereas pyruvate and other TCA cycle metabolites remain unchanged in Drp1 knockdown cells. Additionally, silencing Drp1 activates AMPK to stimulate the expression glycogen synthase 1 (GYS1) mRNA …

Phosphatidic Acid Binding To Patched Contributes To The Inhibition Of Smoothened And Hedgehog Signaling In Drosophila Wing Development, Jie Zhang, Yajuan Liu, Chi Wang, Craig W. Vander Kooi, Jianhang Jia

Markey Cancer Center Faculty Publications

Hedgehog (Hh) signaling controls growth and patterning during embryonic development and homeostasis in adult tissues. Hh binding to the receptor Patched (Ptc) elicits intracellular signaling by relieving Ptc-mediated inhibition of the transmembrane protein Smoothened (Smo). We uncovered a role for the lipid phosphatidic acid (PA) in the regulation of the Hh pathway in Drosophila melanogaster. Deleting the Ptc C-terminal tail or mutating the predicted PA-binding sites within it prevented Ptc from inhibiting Smo in wing discs and in cultured cells. The C-terminal tail of Ptc directly interacted with PA in vitro, an association that was reduced by Hh, and increased …

Regulated Translocation Of Neutral Sphingomyelinase-2 To The Plasma Membrane Drives Insulin Resistance In Steatotic Hepatocytes, Salim S. El-Amouri, Alexander A. Karakashian, Erhard Bieberich, Mariana N. Nikolova‑Karakashian

Markey Cancer Center Faculty Publications

Abstract Obesity-associated diabetes is linked to the accumulation of ceramide in various organs, including the liver. The exact mechanisms by which ceramide contributes to diabetic pathology are unclear, but one proposed scenario is that ceramide accumulation may inhibit insulin signaling pathways. It is unknown however whether the excess ceramide is generated proximal to the insulin receptor, that is, at the plasma membrane (PM), where it could affect the insulin signaling pathway directly, or the onset of insulin resistance is due to ceramide- induced mitochondrial dysfunction and/or lipotoxicity. Using hepatic cell lines and primary cultures, gain- and loss- of function approach, …

Stat3 Modulates Cd4+ T Mitochondrial Dynamics And Function In Aging, Emelia Zukowski, Marco Sannella, Jack Donato Rockhold, Gabriella Kalantar, Jingting Yu, Sara Santacruz-Calvo, Madison K. Kuhn, Nasun Hah, Ling Ouyang, Tzu-Wen Wang, Lyanne Murphy, Heather Marszalkowski, Kaleigh Gibney, Micah J. Drummond, Elizabeth A. Proctor, Hatice Hasturk, Barbara S. Nikolajczyk, Leena P. Bharath

Markey Cancer Center Faculty Publications

Aging promotes numerous intracellular changes in T cells that impact their effector function. Our data show that aging promotes an increase in the localization of STAT3 to the mitochondria (mitoSTAT3), which promotes changes in mitochondrial dynamics and function and T-cell cytokine production. Mechanistically, mitoSTAT3 increased the activity of aging T-cell mitochondria by increasing complex II. Limiting mitoSTAT3 using a mitochondria-targeted STAT3 inhibitor, Mtcur-1 lowered complex II activity, prevented age-induced changes in mitochondrial dynamics and function, and reduced Th17 inflammation. Exogenous expression of a constitutively phosphorylated form of STAT3 in T cells from young adults mimicked changes in mitochondrial dynamics and …

Asparagine Restriction Enhances Cd8+ T Cell Metabolic Fitness And Antitumoral Functionality Through An Nrf2-Dependent Stress Response, J. N. Rashida Gnanaprakasam, Bhavana Kushwaha, Lingling Liu, Xuyong Chen, Siwen Kang, Tingting Wang, Teresa A. Cassel, Christopher M. Adams, Richard M. Higashi, David A. Scott, Gang Xin, Zihai Li, Jun Yang, Andrew N. Lane, Teresa Whei-Mei Fan, Ji Zhang, Ruoning Wang

Markey Cancer Center Faculty Publications

Robust and effective T cell immune surveillance and cancer immunotherapy require proper allocation of metabolic resources to sustain energetically costly processes, including growth and cytokine production. Here, we show that asparagine (Asn) restriction on CD8+ T cells exerted opposing effects during activation (early phase) and differentiation (late phase) following T cell activation. Asn restriction suppressed activation and cell cycle entry in the early phase while rapidly engaging the nuclear factor erythroid 2-related factor 2 (NRF2)-dependent stress response, conferring robust proliferation and effector function on CD8+ T cells during differentiation. Mechanistically, NRF2 activation in CD8+ T cells conferred by Asn restriction …

Integrative Analysis Of Mendelian Randomization And Gene Expression Profiles Reveals A Null Causal Relationship Between Adiponectin And Diabetic Retinopathy, Ao Zhang, Hui Wu, Chi Wang, Suyan Tian

Markey Cancer Center Faculty Publications

Observational studies have been conducted to investigate the correlation between adiponectin and diabetic retinopathy (DR), but no consistent relationship has been established. In this study, we employed an integrative analysis that combined Mendelian randomization (MR) and bioinformatics analyses to comprehensively explore the association between DR and adiponectin, aiming to provide a unified answer of their relationship. Using the inverse-variance weighted (IVW) method, the odd ratio (OR) of developing DR per 1 mg/dL increment in genetically predicted log- transformed adiponectin concentration was estimated to be 0.949 (P = 0.557). Other robust MR methods produced consistent results, confirming the absence of a …

Noncovalent Interactions That Tune The Reactivities Of The Flavins In Bifurcating Electron Transferring Flavoprotein, María González-Viegas, Rajiv K. Kar, Anne-Frances Miller, Maria-Andrea Mroginski

Markey Cancer Center Faculty Publications

Bifurcating electron transferring flavoproteins (Bf-ETFs) tune chemically identical flavins to two contrasting roles. To understand how, we used hybrid quantum mechanical molecular mechanical calculations to characterize noncovalent interactions applied to each flavin by the protein. Our computations replicated the differences between the reactivities of the flavins: the electron transferring flavin ( ETflavin) was calculated to stabilize anionic semiquinone (ASQ) as needed to execute its single-electron transfers, whereas the Bf flavin (Bfflavin) was found to disfavor the ASQ state more than does free flavin and to be less susceptible to reduction. The stability of ETflavin ASQ was attributed in part to …