It is believed that by perturbing the epigenetic landscape of chromatin, the pan HDAC inhibitors exert genome wide changes in both myocytes as well as other cell lineages in the intact heart. However, the molecular underpin ning of selleck chemicals the altered gene expression in myocytes versus non myocyte cells in the Inhibitors,Modulators,Libraries intact heart treated with pan HDACIs is poorly understood. The batch to batch variability that is encountered in cardiac myocytes in pri mary cultures makes them less suitable to answer this question with rigor. The H9c2 cells have emerged as an excellent in vitro alternative to primary cardiac myocytes. Although lack ing the elaborate contractile apparatus of bona fide cardiac myocytes, H9c2 cells elicit robust hypertrophy associated signature of fetal gene expression in response to angiotensin II, phenylephrine and IL 18.
additionally, akin to what occurs in the intact heart, pathological hypertrophy of H9c2 cardiac Inhibitors,Modulators,Libraries myocytes could be attenu ated by pan HDAC inhibitors, TSA and CBHA. This study was undertaken with an objective to deter mine genome wide responses of H9c2 cardiac myocytes to two distinct pan HDACIs. We exposed H9c2 cells to either CBHA or TSA for 6 and 24 h and analyzed their transcriptomes by whole genome Illumina microarrays. We also subjected the differentially expressed genes of H9c2 cells, induced by CBHA and TSA treatments, to theoretical analyses using Ingenuity Pathway Analysis, Kyoto Encyclopedia of Genes and Genomes and Core TF software programs.
Inhibitors,Modulators,Libraries Our data revealed that although CBHA and TSA elicited unique signatures of gene expression at Inhibitors,Modulators,Libraries 6h and 24h time points, both HDACIs suppressed a number of common gene networks putatively involved in pro inflammatory causes and consequences of pathological cardiac hypertrophy. Results H9c2 cardiac myocytes constitutively express all major HDACs and sirtuins We have shown previously that IL 18 induced patho logical hypertrophy in the intact heart and in H9c2 cells were attenuated by TSA and CBHA that caused hyper acetylation of histones in the chromatin both in vivo and in vitro. Modification of histones by pan HDAC inhibitors are mediated by their ability to inhibit Class I and II HDACs. pan HDAC inhibitors do not affect sir tuins. Since the status of expression of various HDACs in H9c2 cells in not known, we began these studies by assessing the expression and sub cellular localization of various HDACs and sirtuins in H9c2 cells.
As shown in the representative western blots, although mono specific antibodies readily detected all major HDACs and Inhibitors,Modulators,Libraries sirtuins their relative expression and subcellular localizations in the extracts Fluoro Sorafenib of H9c2 cells were quite different. For example, HDAC 1, HDAC 2, HDAC 3, HDAC 5 and HDAC 7 are mainly localized in the nucleus of H9c2 cells that elicit nearly equal expres sion of HDAC 4 and HDAC 6 in their cytoplasm and nuclei.