In Vivo Analysis of Troponin C Knock-In (A8V) Mice Evidence that TNNC1 Is a Hypertrophic Cardiomyopathy Susceptibility Gene
CIRCULATION-CARDIOVASCULAR GENETICS
Authors: Martins, Adriano S.; Parvatiyar, Michelle S.; Feng, Han-Zhong; Bos, J. Martijn; Gonzalez-Martinez, David; Vukmirovic, Milica; Turna, Rajdeep S.; Sanchez-Gonzalez, Marcos A.; Badger, Crystal-Dawn; Zorio, Diego A. R.; Singh, Rakesh K.; Wang, Yingcai; Jin, J. -P.; Ackerman, Michael J.; Pinto, Jose R.
Abstract
Background Mutations in thin-filament proteins have been linked to hypertrophic cardiomyopathy, but it has never been demonstrated that variants identified in the TNNC1 (gene encoding troponin C) can evoke cardiac remodeling in vivo. The goal of this study was to determine whether TNNC1 can be categorized as an hypertrophic cardiomyopathy susceptibility gene, such that a mouse model can recapitulate the clinical presentation of the proband. Methods and Results The TNNC1-A8V proband diagnosed with severe obstructive hypertrophic cardiomyopathy at 34 years of age exhibited mild-to-moderate thickening in left and right ventricular walls, decreased left ventricular dimensions, left atrial enlargement, and hyperdynamic left ventricular systolic function. Genetically engineered knock-in (KI) mice containing the A8V mutation (heterozygote=KI-TnC-A8V(+/-); homozygote=KI-TnC-A8V(+/+)) were characterized by echocardiography and pressure-volume studies. Three-month-old KI-TnC-A8V(+/+) mice displayed decreased ventricular dimensions, mild diastolic dysfunction, and enhanced systolic function, whereas KI-TnC-A8V(+/-) mice displayed cardiac restriction at 14 months of age. KI hearts exhibited atrial enlargement, papillary muscle hypertrophy, and fibrosis. Liquid chromatography-mass spectroscopy was used to determine incorporation of mutant cardiac troponin C (approximate to 21%) into the KI-TnC-A8V(+/-) cardiac myofilament. Reduced diastolic sarcomeric length, increased shortening, and prolonged Ca2+ and contractile transients were recorded in intact KI-TnC-A8V(+/-) and KI-TnC-A8V(+/+) cardiomyocytes. Ca2+ sensitivity of contraction in skinned fibers increased with mutant gene dose: KI-TnC-A8V(+/+)>KI-TnC-A8V(+/-)>wild-type, whereas KI-TnC-A8V(+/+) relaxed more slowly on flash photolysis of diazo-2. Conclusions The TNNC1-A8V mutant increases the Ca2+-binding affinity of the thin filament and elicits changes in Ca2+ homeostasis and cellular remodeling, which leads to diastolic dysfunction. These in vivo alterations further implicate the role of TNNC1 mutations in the development of cardiomyopathy.
LukS-PV Inhibits Hepatocellular Carcinoma Cells Migration via the TNNC1/PI3K/AKT Axis
ONCOTARGETS AND THERAPY
Authors: Ma, Fan; Wang, Ziran; Qiang, Yawen; Xu, Liangfei; Ding, Pengsheng; Wang, Yangyan; Ma, Xiaoling
Abstract
Purpose: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. LukS-PV is the S component of Panton-Valentine leucocidin (PVL), a toxin secreted by Staphylococcus aureus. We aimed to investigate the role of LukS-PV in HCC cell migration and the specific molecular mechanism involved. Methods: We used scratch assays to detect the mobility of liver cancer cells treated with LukS-PV. Quantitative real-time PCR and Western blot analysis were performed to detect the expression levels of related genes. RNA sequencing and quantitative proteomics sequencing were used to assess the transcriptional and proteomic alterations of target genes. RNA sequencing and Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Set Enrichment Analysis (GSEA) pathway analyses revealed the downstream signaling pathway targets of LukS-PV. Results: Our results demonstrated that LukS-PV could inhibit HCC cell migration in a concentration-dependent manner. LukS-PV could also downregulate the expression of TNNC1, which was highly expressed in HCC cells. Additionally, the study showed that LukS-PV inhibited HCC cell migration by downregulating TNNC1. Further studies showed that LukS-PV inhibited the phosphorylation of PI3K/AKT pathway by targeting TNNC1, thereby inhibiting HCC cell migration. Conclusion: Our study demonstrated that LukS-PV has an inhibitory role in the migration of liver cancer cells through the TNNC1/PI3K/AKT axis.