Medicine and Health Sciences Commons^™

Na/K-Atpase Alphα1 Regulates Adipogenesis Via Its Conserved Caveolin Binding Motif, Minqi Huang

Theses, Dissertations and Capstones

The Na/K-ATPase (NKA) was identified in 1957 by Dr. Jens C. Skou. It belongs to the P-type ATPase family, which can actively transport ions across cell membranes by using the energy from adenosine triphosphate (ATP) hydrolysis. During the second half of the 20th century, the molecular mechanism of the NKA catalytic cycle was clarified, and the isoform diversity of NKA in different species and organs was identified. The active ion transport through NKA generates cell membrane ion gradients and the electric potential. Hence, the enzymatic function of NKA is critical for cell viability as well as multiple physiological processes including …

Pnaktide Inhibits Na/K-Atpase Reactive Oxygen Species Amplification And Attenuates Adipogenesis, Komal Sodhi, Kyle Maxwell, Yanling Yan, Jiang Liu, Muhammad Chaudhry, Morgan Getty, Zijian Xie, Nader G. Abraham, Joseph I. Shapiro Md

Biochemistry and Microbiology

Obesity has become a worldwide epidemic and is a major risk factor for metabolic syndrome. Oxidative stress is known to play a role in the generation and maintenance of an obesity phenotype in both isolated adipocytes and intact animals. Because we had identified that the Na/K-ATPase can amplify oxidant signaling, we speculated that a peptide designed to inhibit this pathway, pNaKtide, might ameliorate an obesity phenotype. To test this hypothesis, we first performed studies in isolated murine preadipocytes (3T3L1 cells) and found that pNaKtide attenuated oxidant stress and lipid accumulation in a dose-dependent manner. Complementary experiments in C57Bl6 mice fed …

Pparδ Binding To Heme Oxygenase 1 Promoter Prevents Angiotensin Ii-Induced Adipocyte Dysfunction In Goldblatt Hypertensive Rats, Komal Sodhi, Nitin Puri, Dong Hyun Kim, Terry D. Hinds Jr., Lance A. Stechschulte, Gaia Favero, Luigi Rodella, Joseph I. Shapiro M.D., David C. Jude, Nader X. Abraham

Biochemistry and Microbiology

Abstract:

OBJECTIVE: Renin–angiotensin system (RAS) regulates adipogenic response with adipocyte hypertrophy by increasing oxidative stress. Recent studies have shown the role of peroxisome proliferator-activated receptor-d (PPARδ) agonist in attenuation of angiotensin II-induced oxidative stress. The aim of this study was to explore a potential mechanistic link between PPARδ and the cytoprotective enzyme heme oxygenase-1 (HO-1) and to elucidate the contribution of HO-1 to the adipocyte regulatory effects of PPARδ agonism in an animal model of enhanced RAS, the Goldblatt 2 kidney 1 clip (2K1C) model.

METHOD: We first established a direct stimulatory effect of the PPARδ agonist (GW 501516) on …

Cyclooxygenase-2 Dependent Metabolism Of 20-Hete Increases Adiposity And Adipocyte Enlargement In Mesenchymal Stem Cell-Derived Adipocytes, Dong Hyun Kim, Nitin Puri, Komal Sodhi, John R. Falck, Nader G. Abraham, Joseph I. Shapiro M.D., Michal L. Schwartzman

Biochemistry and Microbiology

Abstract 20-Hydroxy-5,8,11,14-eicosatetraenoic acid (20-HETE), a product of the cytochrome P450 (CYP)-catalyzed [1] -hydroxylation of arachidonic acid, induces oxidative stress and, in clinical studies, is associated with increased body mass index (BMI) and the metabolic syndrome. This study was designed to examine the effects of exogenous 20- HETE on mesenchymal stem cell (MSC)-derived adipocytes.

The expression levels of CYP4A11 and CYP4F2 (major 20-HETE synthases in humans) in MSCs decreased during adipocyte differentiation; however, exogenous administration of 20-HETE (0.1–1 M) increased adipogenesis in a dose dependent manner in these cells ( P < 0.05). The inability of a 20-HETE analog to reproduce these effects suggested the involvement of a metabolic product of 20-HETE in mediating its pro-adipogenic effects. A cyclooxygenase (COX)-1 selective inhibitor enhanced, whereas a COX-2 selective or a dual COX-1/2 inhibitor attenuated adipogenesis induced by 20-HETE. The COX-derived metabolite of 20-HETE, 20-OH-PGE 2 , enhanced adipogenesis and lipid accumulation in MSCs. The pro-adipogenic effects of 20-HETE and 20-OH-PGE 2 resulted in the increased expression of the adipogenic regulators PPAR and -catenin in MSC-derived adipocytes. Taken together we show for the fi rst time that 20-HETE-derived COX-2-dependent 20-OH-PGE 2 enhances mature infl amed adipocyte hypertrophy in MSC undergoing adipogenic differentiation. — Kim, D. H., N. Puri, K. Sodhi, J. R. Falck, N. G. Abraham, J. Shapiro, and M. L. Schwartzman. Cyclooxygenase-2 dependent metabolism of 20-HETE increasesadiposity and adipocyte enlargement in mesenchymal stem cell-derived adipocytes.

Prieurianin Causes Weight Loss In Diet-Induced Obese Mice And Inhibits Adipogenesis In Cultured Preadipocytes, Ahmed Kablan, Rudel A. Saunders, Maria Szkudlarek-Mikho, Andrew J.B. Chin, Raul M. Bosio, Kazuyuki Fujii, Joseph I. Shapiro M.D., Khew-Voon Chin

Biochemistry and Microbiology

The global increase in the incidence of obesity has emerged as one of the most serious public health risks in recent years. Despite the enormity of the obesity pandemic, there are currently only two FDA-approved therapies for its treatment and these drugs exhibit modest effi cacy and have limiting side effects. Prieurianin is a plant limonoid product that deters feeding in insect larvae. We investigated in this study the effects of prieurianin on weight loss and adipogenesis. Our results showed that prieurianin causes weight loss by reducing energy intake in obese mice on highcalorie diet. We also found that prieurianin …