Barbara Roman1, Pawandeep Kaur2, Deepthi Ashok3, Mark Kohr4, Roopa Biswas5, Brian O'Rourke3, Charles Steenbergen6, Samarjit Das7. 1. Department of Pathology, Johns Hopkins School of Medicine, Baltimore, MD, United States of America. 2. Department of Anesthesiology & Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, MD, United States of America. 3. Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, United States of America. 4. Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States of America. 5. Department of Anatomy, Physiology and Genetics, School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States of America. 6. Department of Pathology, Johns Hopkins School of Medicine, Baltimore, MD, United States of America. Electronic address: csteenb1@jhmi.edu. 7. Department of Pathology, Johns Hopkins School of Medicine, Baltimore, MD, United States of America; Department of Anesthesiology & Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, MD, United States of America. Electronic address: sdas11@jhmi.edu.
Abstract
AIMS: In cardiomyocytes, there is microRNA (miR) in the mitochondria that originates from the nuclear genome and matures in the cytoplasm before translocating into the mitochondria. Overexpression of one such miR, miR-181c, can lead to heart failure by stimulating reactive oxygen species (ROS) production and increasing mitochondrial calcium level ([Ca2+]m). Mitochondrial calcium uptake 1 protein (MICU1), a regulatory protein in the mitochondrial calcium uniporter complex, plays an important role in regulating [Ca2+]m. Obesity results in miR-181c overexpression and a decrease in MICU1. We hypothesize that lowering miR-181c would protect against obesity-induced cardiac dysfunction. METHODS AND RESULTS: We used an in vivo mouse model of high-fat diet (HFD) for 18 weeks and induced high lipid load in H9c2 cells with oleate-conjugated bovine serum albumin in vitro. We tested the cardioprotective role of lowering miR-181c by using miR-181c/d-/- mice (in vivo) and AntagomiR against miR-181c (in vitro). HFD significantly upregulated heart levels of miR-181c and led to cardiac hypertrophy in wild-type mice, but not in miR-181c/d-/- mice. HFD also increased ROS production and pyruvate dehydrogenase activity (a surrogate for [Ca2+]m), but the increases were alleviated in miR-181c/d-/- mice. Moreover, miR-181c/d-/- mice fed a HFD had higher levels of MICU1 than did wild-type mice fed a HFD, attenuating the rise in [Ca2+]m. Overexpression of miR-181c in neonatal ventricular cardiomyocytes (NMVM) caused increased ROS production, which oxidized transcription factor Sp1 and led to a loss of Sp1, thereby slowing MICU1 transcription. Hence, miR-181c increases [Ca2+]m through Sp1 oxidation and downregulation of MICU1, suggesting that the cardioprotective effect of miR-181c/d-/- results from inhibition of Sp1 oxidation. CONCLUSION: This study has identified a unique nuclear-mitochondrial communication mechanism in the heart orchestrated by miR-181c. Obesity-induced overexpression of miR-181c increases [Ca2+]m via downregulation of MICU1 and leads to cardiac injury. A strategy to inhibit miR-181c in cardiomyocytes can preserve cardiac function during obesity by improving mitochondrial function. Altering miR-181c expression may provide a pharmacologic approach to improve cardiomyopathy in individuals with obesity/type 2 diabetes.
AIMS: In cardiomyocytes, there is microRNA (miR) in the mitochondria that originates from the nuclear genome and matures in the cytoplasm before translocating into the mitochondria. Overexpression of one such miR, miR-181c, can lead to heart failure by stimulating reactive oxygen species (ROS) production and increasing mitochondrial calcium level ([Ca2+]m). Mitochondrial calcium uptake 1 protein (MICU1), a regulatory protein in the mitochondrial calcium uniporter complex, plays an important role in regulating [Ca2+]m. Obesity results in miR-181c overexpression and a decrease in MICU1. We hypothesize that lowering miR-181c would protect against obesity-induced cardiac dysfunction. METHODS AND RESULTS: We used an in vivo mouse model of high-fat diet (HFD) for 18 weeks and induced high lipid load in H9c2 cells with oleate-conjugated bovine serum albumin in vitro. We tested the cardioprotective role of lowering miR-181c by using miR-181c/d-/- mice (in vivo) and AntagomiR against miR-181c (in vitro). HFD significantly upregulated heart levels of miR-181c and led to cardiac hypertrophy in wild-type mice, but not in miR-181c/d-/- mice. HFD also increased ROS production and pyruvate dehydrogenase activity (a surrogate for [Ca2+]m), but the increases were alleviated in miR-181c/d-/- mice. Moreover, miR-181c/d-/- mice fed a HFD had higher levels of MICU1 than did wild-type mice fed a HFD, attenuating the rise in [Ca2+]m. Overexpression of miR-181c in neonatal ventricular cardiomyocytes (NMVM) caused increased ROS production, which oxidized transcription factor Sp1 and led to a loss of Sp1, thereby slowing MICU1 transcription. Hence, miR-181c increases [Ca2+]m through Sp1 oxidation and downregulation of MICU1, suggesting that the cardioprotective effect of miR-181c/d-/- results from inhibition of Sp1 oxidation. CONCLUSION: This study has identified a unique nuclear-mitochondrial communication mechanism in the heart orchestrated by miR-181c. Obesity-induced overexpression of miR-181c increases [Ca2+]m via downregulation of MICU1 and leads to cardiac injury. A strategy to inhibit miR-181c in cardiomyocytes can preserve cardiac function during obesity by improving mitochondrial function. Altering miR-181c expression may provide a pharmacologic approach to improve cardiomyopathy in individuals with obesity/type 2 diabetes.
Authors: Michael Kohlhaas; Ting Liu; Andreas Knopp; Tanja Zeller; Mei Fang Ong; Michael Böhm; Brian O'Rourke; Christoph Maack Journal: Circulation Date: 2010-03-29 Impact factor: 29.690
Authors: Mark J Kohr; Junhui Sun; Angel Aponte; Guanghui Wang; Marjan Gucek; Elizabeth Murphy; Charles Steenbergen Journal: Circ Res Date: 2010-12-30 Impact factor: 17.367
Authors: Yasemin Sancak; Andrew L Markhard; Toshimori Kitami; Erika Kovács-Bogdán; Kimberli J Kamer; Namrata D Udeshi; Steven A Carr; Dipayan Chaudhuri; David E Clapham; Andrew A Li; Sarah E Calvo; Olga Goldberger; Vamsi K Mootha Journal: Science Date: 2013-11-14 Impact factor: 47.728
Authors: Clare V Logan; György Szabadkai; Jenny A Sharpe; David A Parry; Silvia Torelli; Anne-Marie Childs; Marjolein Kriek; Rahul Phadke; Colin A Johnson; Nicola Y Roberts; David T Bonthron; Karen A Pysden; Tamieka Whyte; Iulia Munteanu; A Reghan Foley; Gabrielle Wheway; Katarzyna Szymanska; Subaashini Natarajan; Zakia A Abdelhamed; Joanne E Morgan; Helen Roper; Gijs W E Santen; Erik H Niks; W Ludo van der Pol; Dick Lindhout; Anna Raffaello; Diego De Stefani; Johan T den Dunnen; Yu Sun; Ieke Ginjaar; Caroline A Sewry; Matthew Hurles; Rosario Rizzuto; Michael R Duchen; Francesco Muntoni; Eamonn Sheridan Journal: Nat Genet Date: 2013-12-15 Impact factor: 38.330
Authors: Hemanth N Banavath; Barbara Roman; Nathan Mackowski; Debjit Biswas; Junaid Afzal; Yohei Nomura; Soroosh Solhjoo; Brian O'Rourke; Mark Kohr; Elizabeth Murphy; Charles Steenbergen; Samarjit Das Journal: J Am Heart Assoc Date: 2019-12-05 Impact factor: 5.501
Authors: Robert E Brainard; Lewis J Watson; Angelica M Demartino; Kenneth R Brittian; Ryan D Readnower; Adjoa Agyemang Boakye; Deqing Zhang; Joseph David Hoetker; Aruni Bhatnagar; Shahid Pervez Baba; Steven P Jones Journal: PLoS One Date: 2013-12-18 Impact factor: 3.240
Authors: Kei Akiyoshi; Gretha J Boersma; Miranda D Johnson; Fernanda Carrizo Velasquez; Brittany Dunkerly-Eyring; Shannon O'Brien; Atsushi Yamaguchi; Charles Steenbergen; Kellie L K Tamashiro; Samarjit Das Journal: PLoS One Date: 2021-12-08 Impact factor: 3.240