Progress in epigenetics research in diabetic vascular diseases / 中华内分泌代谢杂志

The concept of epigenetics was first proposed by Waddington in 1942,referring to phenotypic changes that are not related to the underlying DNA sequence,yet alterations in the level and function of gene expression can be heritable,such as DNA methylation,histone modifications,microRNA interference,etc.Phenotype changes while genotype remains unchanged,this controlled mechanism can be kept stable throughout cell division,proliferation,and subsequent process of development.This process thus may cause corresponding changes in the pathophysiology,which are correlated with the occurrence of cancer,immune disorder,cardiovascular disease,metabolic syndrome and so on.Diabetes mellitus is the third heaviest chronic diseases in the world,and does serious harm to human health,especially the diabetic vascular diseases.Even if the blood glucose level is controlled in an ideal state,vascular inflammation still persists,indicating the existence of metabolic memory.Studies have suggested that the pathogenesis can be elucidated at the level of epigenetics.This paper mainly focuses on DNA methylation,histone modifications,and is an overview of epigenetics research progress in diabetic vascular diseases.

Expression of interleukin-17 in diabetic macroangiopathy and the mechanism of intervention with resveratrol / 中华内分泌代谢杂志

Objective To study the expression of interleukin-17 (IL-17) in diabetic rat aorta and the effect of intervention with resveratrol,meanwhile,to explore the potential mechanisms of IL-17 induced diabetic vascular diseases and the protective role played by resveratrol in the epigenetic field.Methods The experiment was carried out in 4 groups:normal control group(NC),normal interventional group(NB),diabetic group(DM),and diabetic interventional group(DB),NB and DB groups were intervened with resveratrol.Immunohistochemistry was used to observe the histological localization of IL-17 and to measure the thickness of rat abdominal aorta.Western blotting,real-time PCR,and methylation-specific PCR were used respectively to compare the expression of IL-17 protein and mRNA,as well as DNA methylation in 4 groups.Results IL-17 mainly expressed in arterial intima of diabetic rats,the abdominal aorta in DM group was obviously thicker than that in NC and DB groups(P＜0.05).IL-17 protein and mRNA expressions in DM group were significantly higher than NC group(P＜0.05),and were reduced in NB and DB groups compared with NC and DM groups respectively.While DNA methylation levels of IL-17 in DM group were significantly lower than NC group(P＜0.01),however,the levels in NB and DB groups were elevated accordingly as compared with corresponding groups.Conclusions The increased levels of IL-17 in aorta of diabetic rats suggests that IL-17 is involved in the process of inflammatory responses to diabetic macrovascular diseases,while resveratrol could inhibit the expression,it may play a role in protecting aorta,and the regulation of IL-17 gene promoter DNA methylation levels may be the potential mechanism underlying these two phenomena.

Negative regulation of cells proliferation by Gax gene and its mechanisms / 生物医学工程学杂志

Gax gene is a newly found negative transcriptional regulator of cells proliferation. This paper introduces the detection and structural features of Gax, details the inhibitory effect of Gax on the proliferation of vascular smooth muscle cells, vascular endothelial cells and cancer cells, and explains the putative mechanisms therein involved. The potential for providing therapeutic insights into human diseases by modulating Gax activity is prospected.

Effect of Ad-Gax transfection on apoptosis of human lung adenocarcinoma A549 cells and its mechanism / 中国肺癌杂志

<p><b>BACKGROUND</b>Apoptosis is closely related to development of lung cancer. It is a strategy of lung cancer therapy to induce apoptosis. The aim of this study is to explore the effects of growth arrest-specific homeobox (Gax) transfection on apoptosis and expression of Bcl-2 and Bax proteins of human lung adenocarcinoma A549 cells.</p><p><b>METHODS</b>A549 cells were transfected with Gax gene by a replication-deficient adenovirus expressing the hemagglutinin-tagged Gax cDNA (Ad-Gax). Apoptosis of A549 cells was observed by transmission electronic microscope and terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) positive staining. Apoptotic rate of A549 cells was evaluated by flow cytometry. Expressions of Bcl-2 and Bax proteins in A549 cells were detected by immunocytochemistry.</p><p><b>RESULTS</b>Before Ad-Gax transfection, none or few of TUNEL-positive A549 cells were detected. After Ad-Gax transfection, a marked increase in TUNEL-positive staining occurred, especially at 24 h later. The ratio of apoptosis of A549 cellsin non-transfection group and transfection groups at 12 h, 24 h, 48 h were 0.25%, 12.57%, 17.29%, 15.03%, respectively. Compared with non-transfection group, the apoptotic rates of transfection groups increased significantly (Chi-square value was 7.357, 11.126 and 9.943 respectively, P < 0.01). The average optical density (AOD) of Bcl-2 protein in A549 cells in non-transfection group and transfection groups at 12 h, 24 h, 48 h were 2.02±0.07, 1.79±0.02, 1.25±0.51 and 1.21±0.24 respectively. Compared with non-transfection group, AOD of Bcl-2 protein in A549 cells in transfection groups decreased significantly (t value was 6.651, 7.089 and 7.438 respectively, P < 0.01). On the other hand, Bax protein expression in transfection groups increased, the AODs of Bax were 4.49±0.61, 4.24±0.37 and 3.95±0.43, respectively. Compared with non-transfection group (3.12±0.42), AOD of Bax protein in A549 celle in transfection groups increased significantly (t value was 7.469, 7.287 and 6.473 respectively, P < 0.01). In the Ad-Gax transfection groups the lower Bcl-2/Bax ratio was, the higher the apoptotic rate of A549 cells was (r=-0.49, P < 0.01).</p><p><b>CONCLUSIONS</b>Ad-Gax transfection can induce A549 cells apoptosis. Possible mechanism is that Gax can downregulate Bcl-2 protein expression and upregulate Bax protein expression, and A549 cells apoptosis is related to the Bcl-2/Bax ratio.</p>

Effects of Gax gene transfection on proliferation and expression of proto-oncogenes in A549 cells / 中国肺癌杂志

<p><b>BACKGROUND</b>Lung cancer is the leading cancer of malignant tumor in China.It is the direction that poeple make efforts to seek gene therapy of lung cancer. The aim of this study is to explore the effects of transfected growth arrest-specific homeobox gene (Gax gene) on the proliferation and expressions of c-fos and c-jun mRNA in A549 cells.</p><p><b>METHODS</b>A549 cells were transfected with Gax gene by adenovirus. Expressions of Gax mRNA and protein were detected by RT-PCR and immunocytochemistry. The expressions of c-fos and c-jun mRNA were evaluated by RT-PCR. The proliferation inhibition effect of Gax transfection on A549 cells was evaluated by MTT assay.</p><p><b>RESULTS</b>Only in the A549 cells transfected with Gax gene the Gax expression was confirmed by RT-PCR and immunocytochemistry. Compared with that in the control group, c-fos and c-jun mRNA level decreased significantly in Gax-transfected A549 cells (t=7.755, P < 0.01; t= 5.938 , P < 0.01). MTT assay showed that the proliferation inhibition rates of A549 cells transfected by Ad-Gax for 24h, 48h and 72h were (47.35±5.36)%, (54.96±1.78)%, and (65.39±5.11)% respectively. And these proliferation inhibition rates were significantly higher than those in the control group (Chi-Square=7.152, 9.431 and 12.847, P < 0.01).</p><p><b>CONCLUSIONS</b>Gax gene can inhibit the proliferation of A549 cells. Its molecular mechanism may be through down-regulating the expressions of c-fos and c-jun.</p>

Effects of Gax gene transfection on proto-oncogene expression and proliferation of PASMCs in rats under hypoxia conditions / 中国病理生理杂志

AIM:To explore the effects of Gax gene transfection on expressions of c-fos and c-jun mRNA and proliferation of pulmonary arterial smooth muscle cells (PASMCs) in rat under hypoxia. METHODS: PASMCs were transfected with Gax gene by Ad-Gax. Under normal oxygentention (21% O2) or hypoxia (2.5% O2) for 12 h condition, expressions of Gax mRNA and protein in PASMCs were detected by RT-PCR and immunocytochemistry. The expressions of c-fos and c-jun mRNA were evaluated by RT-PCR. [3H]-TdR incorporation was used to measure the PASMCs proliferation. RESULTS: The Gax overexpression in transfection group was confirmed by RT-PCR and immunocytochemistry. Under normal oxygentention or hypoxia, the c-fos and c-jun mRNA levels in transfection group were lower than those in the non-transfection group, respectively (P