Heat shock protein 22 reduces phenylephrine-induced cardiomyocytes hypertrophy / 中华急诊医学杂志

Objective To investigate the effect of Hsp22 on phenylephrine-induced cardiomyocytes hypertrophy.Methods Primary rat myocardial cells were isolated and cultured in Department of Cardiology,the First Affiliated Hospital of Zhengzhou University.Cells were divided into four groups randomly:Control group,model group,treatment group with 1 μg/mL Hsp22,and treatment group with 10 μg/mL Hsp22.Phenylephrine stimuli was used to induce cardiomyocytes hypertrophy model.Cell viability was measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.Cardiomyocytes surface area was evaluated by α-actin immunofluorescence staining.Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the transcription level of hypertrophic markers.Reactive oxygen species level was detected by 2',7'-Dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probe.Apoptosis was detected by TUNEL staining.Signal pathway protein expression was detected by Western blot.SPSS 13.0 was used for statistical analysis.Data were expressed as mean + standard deviation.All data were analyzed by one-way ANOVA between groups.Comparisons between two groups were performed using LSD-t test.A P＜0.05 was considered statistically significant.Results Different concentrations of Hsp22 had no effect on cardiomyocytes viability (F=6.622;P＞0.05).Phenylephrine stimulation significantly increased cardiomyocytes area (t=10.80;P＜0.05),increased the transcription level of hypertrophy markers atrial natriuretic peptide (t=37.72;P＜0.05),type B natriuretic peptide (t=16.85;P＜0.05),and myosin heavy chain beta (t=41.53;P＜0.05).Different concentrations of Hsp22 significantly reduced cardiomyocytes area (PE+ 1 μg/mL Hsp22 t=4.018;P＜0.05;PE+10 μg/mL Hsp22 t=10.80;P＜0.05),reduced the transcription level of hypertrophic markers atrial natriuretic peptide (PE+1 μg/mL Hsp22 t=27.12,P＜0.05;PE+10 μg/mL Hsp22 t=37.72,P＜0.05),type B natriuretic peptide (PE+1 μg/mL Hsp22 t=4.82,P＜0.05;PE+10 μg/mL Hsp22 t=12.74,P＜0.05),and myosin heavy chain beta (PE+1 μg/mL Hsp22 t=23.68,P＜0.05;PE+10 μg/mL Hsp22 t=30.54,P＜0.05).Westem blot showed that Hsp22 increased the activation of AMP-activated protein kinase α (PE+1 μg/mL Hsp22 t=5.89,P＜0.05;PE+10 μg/mL Hsp22 t=5.88,P＜0.05),reduced mTOR phosphorylation level (PE+1 μg/mL Hsp22 t=16.80,P＜0.05;PE+10.μg/mL Hsp22 t=20.46,P＜0.05).Conclusions Hsp22 inhibits cardiomyocytes hypertrophy by activating AMP-activated protein kinase α.Hsp22 may become a potential anti-hypertrophic drug.

Role of HSP22 in atherosclerosis induced by high-fat diet and effects of statin / 中国病理生理杂志

AIM:To evaluate the role of heat shock protein 22(HSP22)in atherosclerosis(AS)induced by high-fat diet and in the intervention with atorvastatin(Ator).METHODS: Total 3 groups of 8 ~9-week-old ApoE-/-, HSP22-/-ApoE-/-and HSP22 +ApoE-/-male mice were used,with 18 mice in each group.After 1 week of adaptive feeding, the mice in each group were randomly divided into 2 subgroups: control group, and Ator group, HSP22 knockout group (KO group)and HSP22 knockout with Ator treatment group(KO+Ator group),and HSP22 overexpression group(Tg group)and HSP22 overexpression with Ator treatment group(Tg+Ator group).Atro at 10 mg· kg-1-d-1was administered to the mice in all Ator groups from the 5th week.The mice in the control groups were given saline.All these mice were fed for 13 weeks.Oil red O staining and HE staining of the aortic wall of the mice were used to measure the atherosclerotic le-sion burdens.The protein levels of HSP22,NF-κB, eNOS, ICAM-1 and IL-6 in the aorta and serum were examined by Western blot,immunohistochemistry and ELISA.RESULTS:Aortic Oil red O staining and HE staining showed that the relative area of aorta plaque in Tg group was less than that in KO group(P<0.05).The protein expression of HSP22 in Tg group was significantly higher than that in control group and KO group,and its expression in control group was signifi-cantly higher than that in KO group.The protein expression of eNOS in Tg group and control group was significantly higher than that in KO group.The protein expression of NF-κB and ICAM-1 in control group was significantly decreased as com-pared with KO group,and their expression was significantly higher than that in Tg group.No difference of serum IL-6 level was found among Tg group,KO group and control group.CONCLUSION:HSP22 gene deletion up-regulates the expres-sion of NF-κB and ICAM-1,and down-regulates the expression of eNOS,leading to accelerating AS.HSP22 overexpression decreases the expression of NF-κB and ICAM-1 and increases the expression of eNOS,thus attenuating AS development. HSP22 gene deletion partially limits the role of Ator in the expression of NF-κB,ICAM-1 and eNOS.HSP22 overexpression amplifies the reduced expression of ICAM-1 by the intervention with Ator,and further attenuates AS development.

Aortic expression of HSP22, TNF-αand eNOS in rats with hyperlipi-demia and effects of atorvastatin / 中国病理生理杂志

AIM:To establish a rat hyperlipidemia model for studying the aortic expression of heat shock protein 22 (HSP22), tumor necrosis factor alpha (TNF-α) and endothelial nitric oxide synthase (eNOS) and the effect of atorvasta-tin intervention.METHODS:Hyperlipidemia model was established in SD rats.Afterwards, the rats were divided into nor-mal control group, high fat group and high fat+atorvastatin intervention group.The expression of HSP22 and TNF-αin the rat aortas was detected by immunohistochemical assay and the expression of eNOS was assessed by Western blotting.RE-SULTS:No detectable expression of HSP22 and TNF-αin the normal control group was observed.However, the expression of HSP22 and TNF-αwas positive in the high fat group and the atorvastatin intervention group.The mean densities of HSP22 and TNF-αpositive particles were significant lower in the atorvastatin intervention group as compared with high fat group ( both P<0.05) .The expression of eNOS protein in the high fat group and atorvastatin intervention group was significantly lower than that in normal control group (P<0.01).However, no marked difference of eNOS protein expression between high fat group and atorvastatins intervention group was observed.CONCLUSION:The expression of HSP22 and TNF-αin the rat aortas is increased in the hyperlipidemia rat model.This effect can be restored by atorvastatin treatment.The expression of eNOS in the rat aortas is decreased in the hyperlipidemia rat model, but this tendency could not be attenuated by atorvastatin.

Overexpression of heat shock protein 22 inhibits the growth of hematopoietic malignant tumor cells / 白血病·淋巴瘤

Objective To investigate the effects of overexpression of heat shock protein 22(HSP22) in hematopoietic malignant tumor cell lines.Methods A lentiviral system was used to mediate transduction of HSP22 complementary DNA-containing expression vector or empty vector into K562 and Namalwa cells.The transduction effeciency was tested by fluorescence microscope scan and flow cytometry.Semi-quantitative RT-PCR and Western blot were used to identify the expression levels of HSP22 mRNA and protein.Growth curve analysis,cell cycle analysis,colony-forming assay,tumor growth in nude mice and apoptosis analysis were used to evaluate the role of HSP22 in K562 and Namalwa cells.Results Lentivector expression systemmediated delivery of HSP22 into K562 and Namalwa cells can inhibit colony forming of K562 and Namalwa cells,the average numbers of colonies per well were 108,72,125 and 80 for K562-V,K562-H,Namalwa-V and Namalwa-H respectively (P =0.000 16 and 0.000 37 for K562 and Namalwa respectively).HSP22 transduction can also inhibit proliferation of Namalwa cells in vitro (P =0.015,0.042 and 0.048 for day 5,6 and 7 respectively) and K562 cells in vivo (P =0.022 for day 21).No significant difference in cell cycle and apoptosis was found in K562 and Namalwa cells compared with controls (all P ＞ 0.05).Conclusion Overexpression of HSP22 could inhibit the growth of hematopoietic malignant tumor cell lines K562 and Namalwa.

Effects of decitabine on heat-shock protein 22 expression in malignant hematopoietic cells / 白血病·淋巴瘤

Objective To investigate the effects and possible mechanisms of decitabine on heat-shock protein 22 (HSP22) expression in hematopoietic tumor cell lines and bone marrow samples from patients with hematopoietic tumor.Methods The expression of HSP22 in 13 hematopoietic tumor cell lines,20 primary patients' samples and 10 normal donor' samples were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR).After HSP22 induction with a demethylating agent decitabine (2 μmol/L),the methylation of the HSP22 promoters in hematopoietic tumor cell lines,healthy donors and bone marrow samples from patients with hematopoietic tumor were detected by methylation specific PCR (MSP).Results Expression of HSP22 was not detected in 13 hematopoietic tumor cell lines,20 primary patients' samples or 10 healthy donors' samples.Decitabine can induce the expression of HSP22 in hematopoietic tumor cell lines and bone marrow samples from patients with hematopoietic tumor.Decitabine can maintain partially demethylation of HSP22 promoters in hematopoietic tumor cell lines.HSP22 promoters were highly methylated in BMMC of the healthy donors and patients with hcmatopoictic tumor.Conclusion Decitabine can induce the expression of HSP22 in hematopoietic tumor cells partly by demethylation of HSP22 promoters.