The plasma membrane integrity is of critical importance for cell homeostasis and function. Physical, chemical or metabolic disruption of the plasma membrane leads to a repair-or-die emergency in the cell. Thus, an efficient plasma membrane repair mechanism is essential for life since disruption of this process due to genetic mutations can result in a number of diseases including muscular dystrophy and associated cardiomyopathy. Previous studies from others and us demonstrated that the membrane repair response in cardiomyocytes is mediated by several proteins including dysferlin and MG53. However, the molecular mechanisms underlying this important physiological process have not been fully defined. Our preliminary data found that anoctamin 5 (Ano5) plays an essential role in membrane repair in myocytes. Ano5 belongs to the anoctamin protein family that includes at least ten proteins all possessing eight transmembrane domains with proved or putative calcium-activated chloride channel (CaCC) functions. Mutations in the ANO5 gene (encoding Ano5) lead to muscular dystrophies in human patients. However, there is little known about the molecular and cellular functions of Ano5 in cardiomyocytes and the molecular mechanisms underlying Ano5-mediated membrane repair remain poorly understood. The long-term goal of this research proposal is to understand the molecular and cellular mechanisms for Ano5 in heart physiology and disease. In pilot studies, we found that Ano5 is primarily localized on the endoplasmic/sarcoplasmic reticulum (ER/SR) and RNAi-silencing of Ano5 shows defective membrane repair in myocytes. Thus, our data present a new biological function for Ano5 in the cellular physiology of muscle cells. In this project, we will focus on testing the hypothesis that Ano5 is involved in the calcium-activated chloride channel (CaCC) activity and plays an essential role in plasma membrane repair of cardiomyocytes. Through manipulating expression of Ano5 and the use of live cell imaging, biochemical markers, ex vivo and in vivo animal model studies, our planned experiments will significantly advance understanding of the mechanisms underlying membrane repair of cardiomyocytes, and begin to define potential therapeutic targets for the regulation of membrane repair capacity to treat the diseases associated with abnormal membrane stability. Disrupted plasma membrane integrity underlies a number of diseases including cardiomyopathy. Our project is designed to understand the molecular and cellular functions of Ano5 in muscle physiology and disease. These studies will aid in defining therapeutic target for the treatment of treatment of heart diseases associated with compromised plasma membrane integrity through the regulation of Ano5-mediated membrane repair capacity.

Public Health Relevance

Plasma membrane repair is a basic physiological process in a cell, and defects in this process lead to a number of human diseases including cardiomyopathy. We are exploring the molecular and cellular mechanisms of membrane repair in heart physiology and disease. These studies will shed light on designing therapeutic strategies for the regulation of membrane repair capacity in the treatment of heart diseases.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL116546-02
Application #
8690963
Study Section
Cardiac Contractility, Hypertrophy, and Failure Study Section (CCHF)
Program Officer
Desvigne-Nickens, Patrice
Project Start
2013-07-01
Project End
2018-03-31
Budget Start
2014-04-01
Budget End
2015-03-31
Support Year
2
Fiscal Year
2014
Total Cost
$369,950
Indirect Cost
$124,950
Name
Loyola University Chicago
Department
Physiology
Type
Schools of Medicine
DUNS #
791277940
City
Maywood
State
IL
Country
United States
Zip Code
60153
Mariano, Andrew; Xu, Li; Han, Renzhi (2014) Highly efficient genome editing via 2A-coupled co-expression of two TALEN monomers. BMC Res Notes 7:628
Cheng, Xiping; Zhang, Xiaoli; Gao, Qiong et al. (2014) The intracellular Ca²? channel MCOLN1 is required for sarcolemma repair to prevent muscular dystrophy. Nat Med 20:1187-92
Zhao, Piming; Torcaso, Audrey; Mariano, Andrew et al. (2014) Anoctamin 6 regulates C2C12 myoblast proliferation. PLoS One 9:e92749
Iyer, Shankar S; He, Qiong; Janczy, John R et al. (2013) Mitochondrial cardiolipin is required for Nlrp3 inflammasome activation. Immunity 39:311-23