Studies On Function Of HFHG5 Gene

According to the latest statistics of world health organization, heart disease mortality is in the first place of death by 12.9%. As a need with long-term and in-depth study of the disease, heart disease has become the world’s problems which scientists are eager to solve. It is well known that the early symptoms of heart disease is pathological myocardial hypertrophy. In order to achieve to cure heart disease fundamentally, the regulating mechanism of myocardial hypertrophy was systematically studied at the molecular level.Existing research showed that HFHG5 were found with high expression in mice model(the aorta banding method)and the specimens of patient tissue, which suggesting that the occurrence of myocardial hypertrophy might be associated with HFHG5. With the analysis of Luciferase report system and CO-IP experiment, researchers found that HFHG5 was associated with TGF-β/Smads signaling pathway and HFHG5 actually interact with Smad3/4, which suggesting that HFHG5 was likely to be involved in the TGF-β/Smads signaling pathway. But the detail of the link between TGF-βsignaling pathways and HFHG5 or the regulating mechanism of myocardial hypertrophy had not been studied, on which it has begun to research.In order to study the mechanism of HFHG5 gene regulating myocardial hypertrophy occurrence, this paper had carried out the following research:(1) In order to facilitate the development of the experiment, it needed to construct the recombinant adenovirus vector pAd-HFHG5 and prepare the adenovirus, that adenovirus Ad-HFHG5 was verified to construct successfully. Ad-HFHG5 was mainly used for the experiment of primary myocardial cells of neonatal rat with the high expression of HFHG5. At the same time, we successfully built a interference vector pSuper-HFHG5-shRNA and verified the existing expression vector pCMV-Myc-h-HFHG5 from the laboratory. This pair of carrier was mainly used for interference and high expression of HFHG5 in vitro study.(2) PE and FBS were respectively used for stimulating the primary myocardial cells of neonatal rat(group AdGFP and group AdHFHG5), which were detected that HFHG5 overexpress after hypertrophic stimulation and which verified that HFHG5 was associated with myocardial hypertrophy.(3) By means of immunofluorescence assay about the position of HFHG5 and Smad4, it has been found that HFHG5 were expressed in the cytoplasm and nucleus and the same position with Smad4 in the cytoplasm. This verified the HFHG5 might be associated with Smad4.(4) Subsequently with the experiment of extracting nuclear /cytoplasmic protein and Western blot experiments, in which it had been found that overexpressing HFHG5 promoted Smad4 into the nucleus and interfering HFHG5 suppressed Smad4 into the nucleus. This proved that HFHG5 regulated the TGF-β/Smads signaling pathway by promoting Smad4 into nucleus.(5) For the preliminary research of the mechanism which Smad4 and HFHG5 transported into nucleus synergistically to regulate downstream, RT-PCR experiments proved that after Smad4 and HFHG5 synergistically transporting into nucleus which activate the expression of downstream hypertrophy related gene. It could be concluded that the molecular mechanism of HFHG5 promoted the occurrence of myocardial hypertrophy mainly was due to this happening that HFHG5 and Smad4 synergistically transports into nucleus and regulated the transcription of downstream hypertrophy related gene.The above experiments confirmed that HFHG5 participated in the TGF-β/Smads signaling pathway and together with Smad4 control the occurrence of myocardial hypertrophy. When HFHG5 expressed under human disturbance, it would inhibit Smad4 transporting into the nucleus and eventually led to the lower expression of myocardial hypertrophy marker gene. The above results provided a new clue to treatment strategy of myocardial hypertrophy disease.