@article {2372, title = {Ribosomal protein S6 kinase beta-1 gene variants cause hypertrophic cardiomyopathy.}, journal = {J Med Genet}, year = {2021}, month = {2021 Dec 16}, abstract = {

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a genetic heart muscle disease with preserved or increased ejection fraction in the absence of secondary causes. Mutations in the sarcomeric protein-encoding genes predominantly cause HCM. However, relatively little is known about the genetic impact of signalling proteins on HCM.

METHODS AND RESULTS: Here, using exome and targeted sequencing methods, we analysed two independent cohorts comprising 401 Indian patients with HCM and 3521 Indian controls. We identified novel variants in ribosomal protein S6 kinase beta-1 () gene in two unrelated Indian families as a potential candidate gene for HCM. The two unrelated HCM families had the same heterozygous missense S6K1 variant (p.G47W). In a replication association study, we identified two S6K1 heterozygotes variants (p.Q49K and p.Y62H) in the UK Biobank cardiomyopathy cohort (n=190) compared with matched controls (n=16 479). These variants are neither detected in region-specific controls nor in the human population genome data. Additionally, we observed an S6K1 variant (p.P445S) in an Arab patient with HCM. Functional consequences were evaluated using representative S6K1 mutated proteins compared with wild type in cellular models. The mutated proteins activated the S6K1 and hyperphosphorylated the rpS6 and ERK1/2 signalling cascades, suggesting a gain-of-function effect.

CONCLUSIONS: Our study demonstrates for the first time that the variants in the gene are associated with HCM, and early detection of the variant carriers can help to identify family members at risk and subsequent preventive measures. Further screening in patients with HCM with different ethnic populations will establish the specificity and frequency of gene variants.

}, issn = {1468-6244}, doi = {10.1136/jmedgenet-2021-107866}, author = {Jain, Pratul Kumar and Jayappa, Shashank and Sairam, Thiagarajan and Mittal, Anupam and Paul, Sayan and Rao, Vinay J and Chittora, Harshil and Kashyap, Deepak K and Palakodeti, Dasaradhi and Thangaraj, Kumarasamy and Shenthar, Jayaprakash and Koranchery, Rakesh and Rajendran, Ranjith and Alireza, Haghighi and Mohanan, Kurukkanparampil Sreedharan and Rathinavel, Andiappan and Dhandapany, Perundurai S} } @article {1644, title = {Myocardin ablation in a cardiac-renal rat model.}, journal = {Sci Rep}, volume = {9}, year = {2019}, month = {2019 Apr 10}, pages = {5872}, abstract = {

Cardiorenal syndrome is defined by primary heart failure conditions influencing or leading to renal injury or dysfunction. Dilated cardiomyopathy (DCM) is a major co-existing form of heart failure (HF) with renal diseases. Myocardin (MYOCD), a cardiac-specific co-activator of serum response factor (SRF), is increased in DCM porcine and patient cardiac tissues and plays a crucial role in the pathophysiology of DCM. Inhibiting the increased MYOCD has shown to be partially rescuing the DCM phenotype in porcine model. However, expression levels of MYOCD in the cardiac tissues of the cardiorenal syndromic patients and the effect of inhibiting MYOCD in a cardiorenal syndrome model remains to be explored. Here, we analyzed the expression levels of MYOCD in the DCM patients with and without renal diseases. We also explored, whether cardiac specific silencing of MYOCD expression could ameliorate the cardiac remodeling and improve cardiac function in a renal artery ligated rat model (RAL). We observed an increase in MYOCD levels in the endomyocardial biopsies of DCM patients associated with renal failure compared to DCM alone. Silencing of MYOCD in RAL rats by a cardiac homing peptide conjugated MYOCD siRNA resulted in attenuation of cardiac hypertrophy, fibrosis and restoration of the left ventricular functions. Our data suggest hyper-activation of MYOCD in the pathogenesis of the cardiorenal failure cases. Also, MYOCD silencing showed beneficial effects by rescuing cardiac hypertrophy, fibrosis, size and function in a cardiorenal rat model.

}, issn = {2045-2322}, doi = {10.1038/s41598-019-42009-z}, author = {Mittal, Anupam and Rana, Santanu and Sharma, Rajni and Kumar, Akhilesh and Prasad, Rishikesh and Raut, Satish K and Sarkar, Sagartirtha and Saikia, Uma Nahar and Bahl, Ajay and Dhandapany, Perundurai S and Khullar, Madhu} }