Epidemiology and genetics of dilated cardiomyopathy in the Indian context

Background: Dilated cardiomyopathy (DCM) still remains to be a poorly understood and less analyzed group of cardiac-muscle disorders when compared to hypertrophic cardiomyopathy (HCM). Also, the vast clinical heterogeneity among the patients has rendered the small and isolated kindred studies less informative on the genetics and epidemiology of DCM. Aim of the study: The study aimed at understanding the epidemiology and genetics of DCMs in the Indian context. Materials and methods/ Statistical analysis: One hundred seven DCM patients and 105 healthy individuals were included in the study for epidemiological and genetic risk factor identification and to fit the possible mode of inheritance. Single′s ascertainment methodology for segregation analysis and Penrose frequency estimates were followed to evaluate for the role of specific epidemiological factors in the disease etiology. Chi-square analysis was carried out to interpret the results statistically. Results and Conclusion: Our study suggests that epidemiological factors like gender, age at onset and vegetarian diet in conjunction with sarcomere gene mutations may play a role in the disease expression. Similarly, segregation analysis for the possible mode of inheritance showed a deviation from the autosomal dominant mode of inheritance, strengthening the underlying genetic heterogeneity of DCM

MMD collaborates with ACSL4 and MBOAT7 to promote polyunsaturated phosphatidylinositol remodeling and susceptibility to ferroptosis

Summary: Ferroptosis is a form of regulated cell death with roles in degenerative diseases and cancer. Excessive iron-catalyzed peroxidation of membrane phospholipids, especially those containing the polyunsaturated fatty acid arachidonic acid (AA), is central in driving ferroptosis. Here, we reveal that an understudied Golgi-resident scaffold protein, MMD, promotes susceptibility to ferroptosis in ovarian and renal carcinoma cells in an ACSL4- and MBOAT7-dependent manner. Mechanistically, MMD physically interacts with both ACSL4 and MBOAT7, two enzymes that catalyze sequential steps to incorporate AA in phosphatidylinositol (PI) lipids. Thus, MMD increases the flux of AA into PI, resulting in heightened cellular levels of AA-PI and other AA-containing phospholipid species. This molecular mechanism points to a pro-ferroptotic role for MBOAT7 and AA-PI, with potential therapeutic implications, and reveals that MMD is an important regulator of cellular lipid metabolism