分泌卷曲相关蛋白4结构特征及其对脂质代谢的作用

分泌卷曲相关蛋白4(SFRP4)是Wnt信号通路的抑制因子,在人类个体发育过程中发挥重要作用。同时,SFRP4基因表达和蛋白分泌异常导致机体发生病理变化。本文介绍了SFRP4基因和蛋白的结构特征、组织分布以及胚胎发育过程中的表达变化。临床研究发现,糖尿病患者血清中SFRP4蛋白水平显著升高,其与胰岛素分泌呈负相关。作为Wnt信号通路的抑制因子,SFRP4在调控脂肪形成、糖代谢以及胰岛素抵抗等生理和病理生理过程中扮演着重要角色。近年来,SFRP4在肥胖、脂质代谢紊乱以及糖尿病发生中的病理作用引起了广泛关注,并取得了重要进展。对其进一步系统深入的研究,不仅可以揭示肥胖、脂质代谢紊乱和糖尿病发生的新机制,也有望发现临床药物治疗新靶点。     

Differential gene expression in response to ventricular unloading in rat and human myocardium

Left ventricular unloading by mechanical assist devices induces myocardial atrophy. We aimed to systematically identify differentially expressed genes in a model of physiological atrophy (unloading of healthy rat myocardium) and compare these changes to those in a unloaded, failing human heart. METHODS: Atrophy in rat hearts was induced by heterotopic transplantation of a donor heart into the abdomen of an isogenic recipient. After one week, donor and recipient RNA was isolated. Differential gene expression was assessed by subtractive hybridization. Two screens with radioactive probes were performed to verify differentially expressed clones. Positive clones were sequenced and cDNA of genes of known homology were used as probes for hybridization with RNA from separate atrophied rat hearts and human tissue from a normal, failing or failing and unloaded left ventricle. RESULTS: We picked 1880 clones from the subtractive hybridization procedure (940/940: forward/reverse runs assessing up- or down-regulation, respectively). The first screen verified 465/140 and the second screen verified 67/30 clones. 24/23 clones were sequenced and 14/10 homologies to known genes were found. In the atrophied heart, respiratory chain and metabolic genes were down-regulated (NADH-DH, cytochrome c oxidase, acetyl-CoA synthetase, myoglobin) and cellular recognition and stress genes were up-regulated (MHC1 and 2, HSP70). In the human heart, cytochrome c oxidase, acetyl-CoA synthetase, and myoglobin expression was increased in the failing heart and returned to normal with unloading. Unloading also resulted in up-regulation of HSP70. CONCLUSIONS: The genetic responses of failing human and healthy rat myocardium to mechanical unloading show similarities that appear to be independent of species differences and/or underlying disease. Thus, heterotopic heart transplantation is a relevant model for investigating the mechanisms of mechanical unloading.     

人胎儿卵细胞凋亡及其凋亡蛋白Caspase-3表达的临床意义

目的探讨人胎儿卵泡形成过程中卵细胞凋亡及其凋亡蛋白Caspase-3的表达意义.方法收集13例行水囊引产终止妊娠的胎儿卵巢,其中孕中期(20～28孕周)7例,孕晚期(29～38孕周)6例.利用原位末端标记法(TUNEL法)和免疫组化法观察胎儿卵泡形成过程中卵细胞凋亡及其凋亡蛋白Caspase-3的表达.结果部分胎儿卵细胞末端标记阳性,孕中期卵细胞凋亡指数[(9.8±1.2)%]大于孕晚期[(3.1±1.0)%],P＜0.01.凋亡相关蛋白Caspase-3在胎儿卵细胞内广泛表达,孕中期阳性单位(36.6±3.1)大于孕晚期(20.2±2.6),P＜0.01.Caspase-3表达与卵细胞凋亡呈正相关.结论胎儿卵泡形成过程中卵细胞发生凋亡,导致生殖细胞丢失,凋亡蛋白Caspase-3可能参与卵细胞凋亡的调控.     

凋亡相关基因caspase-3及Bcl-2在人类大肠腺瘤和大肠癌中的表达及意义

目的　探讨凋亡相关基因caspase 3和Bcl 2在大肠腺瘤及大肠癌组织中的表达及其意义。方法　应用免疫组织化学ABC法检测 2 0例大肠正常黏膜、3 0例大肠腺瘤及 40例大肠癌组织中caspase 3和Bcl 2的表达。用TUNEL法检测细胞凋亡。结果　大肠正常黏膜、腺瘤和大肠癌组织中caspase 3的阳性表达分别为 95 %、70 %、65 %。Bcl 2的阳性表达分别为 15 .0 0 %、86.67%、62 .5 %。正常黏膜组织caspase 3的表达高于大肠腺瘤和大肠癌 (P <0 .0 5 ) ,而Bcl 2表达低于后两者 (P <0 0 5 )。caspase 3及Bcl 2的表达与凋亡指数密切相关 (r =0 73及 -0 89　P <0 0 0 1) ,但均与大肠癌临床病理分期无关。结论　大肠腺瘤及大肠癌组织中caspase 3低表达和Bcl 2的高表达与细胞凋亡异常密切相关 ,可能在大肠腺瘤癌变及大肠癌的发生和发展过程中起重要作用     

凋亡相关基因bcl-2, bax在人类大肠腺癌中的表达意义

目的　探讨ｂｃｌ２ 和ｂａｘ 在人类大肠腺癌中的表达及其意义．方法　运用ＨＥ 染色和免疫组织化学方法对７２ 例人类大肠腺癌进行研究，并采用５ 例正常人类结肠组织作为对照．结果　①大肠腺癌的细胞凋亡随肿瘤分化的不同，而有显著的差异（ Ｐ＜ ０－０１） ，肿瘤的分化程度越高，凋亡指数ＡＩ 值越大．②ｂｃｌ２ 和ｂａｘ 基因在大肠腺癌中均具有较高程度的表达． ③ｂｃｌ２ 和ｂａｘ 基因均与大肠腺癌的分化程度有关（ Ｐ＜ ０－０５） ，肿瘤分化越低，其表达也就越低． ④ｂｃｌ２ 和ｂａｘ 基因在大肠腺癌组织中阳性反应呈显著正相关（ Ｐ＜ ０－０５ ，γ＝ ０－５２３） ．结论　ＨＥ 染色切片可以识别典型的凋亡细胞，大肠腺癌中的细胞凋亡与肿瘤的恶性程度有关，恶性程度越大，细胞凋亡越少；ｂｃｌ２ 与ｂａｘ 基因均与大肠腺癌的细胞凋亡的调控有关，在此过程中二者也相互作用，并且可能在大肠腺癌分化的中晚期共同调控，以抑制细胞凋亡作用为主．     

Localisation of apoptosis and expression of apoptosis related proteins in the synovium of patients with rheumatoid arthritis.

OBJECTIVES: To investigate whether apoptosis occurs in the synovium of rheumatoid arthritis (RA), and the intermediate molecules operating in this process. METHODS: DNA fragmentation was detected by in situ nick end labelling (ISNEL) in the synovium of patients with RA (n = 11) and control patients with femoral neck fracture (n = 5). The expression of proteins p53, p21WAFI/CIPI, c-myc, proliferating cell nuclear antigen (PCNA), and Bcl-2 was also examined by immunohistochemistry. RESULTS: ISNEL positive synovial cells with apoptosis specific morphology were detected in extremely limited areas in only two RA synovial tissue specimens. Proteins p53, p21WAFI/CIPI, and c-myc, known inducers of apoptosis or cell cycle arrest or both, were expressed in the sublining cells independent of ISNEL positive cells. PCNA, a marker for cell proliferation, was observed in the synovial lining cells. Bcl-2, an inhibitor of apoptosis, was expressed mainly in infiltrated lymphocytes and in parts of the sublining layer cells of RA; it also did not correspond with ISNEL staining. CONCLUSIONS: Our findings indicate that RA synovial cells undergo apoptosis in addition to cell proliferation, but the frequency of apoptosis was very low. We suspect that the apoptotic process in the RA synovium may be suppressed by over-expression of Bcl-2. Although expressed proteins p53, p21WAFI/CIPI, and c-myc were present in the RA synovium, these protooncogenes are probably not implicated in the apoptotic process.     

钙调神经磷酸酶在人类心肌中的表达与分布

目的 了解钙调神经磷酸酶(CaN)在人类健康心肌和衰竭心肌中的表达与分布.方法 以12例行移植手术的终末期衰竭心脏和5例因车祸丧生的"健康供体"心脏为研究对象,分别利用免疫组化和Western blot技术对左、右心室中CaN的表达与分布进行研究.结果 CaN在心脏的心肌细胞、纤维母细胞、心外膜间皮细胞中染色阳性,且Western blot实验在后两种细胞中均检测到单一的58 000带,心肌内血管内皮细胞和平滑肌细胞中CaN染色阴性.与"供体"心肌比较,无论左心室还是右心室,衰竭心肌的CaN蛋白水平差异均无统计学意义(衰竭右心室和供体右心室电泳带强度分别为130.20±8.66和139.87±6.21,P=0.33.衰竭左心室和供体左心室电泳带强度分别为106.45和126.34±12.09),且左右心室肌CaN蛋白水平差异也无统计学意义(衰竭心肌左、右心室电泳带强度分别为96.99±10.67和104.58±13.18,P=0.63.供体心肌左、右心室电泳带强度分别为132.12和120.74).结论 CaN存在于人类心脏多数类型细胞中,包括心肌细胞、纤维母细胞和心外膜间皮细胞.心力衰竭时,CaN蛋白水平没有改变.     

舒林酸对人结肠癌细胞凋亡及相关基因表达谱的作用

目的:观察舒林酸对人结肠癌LOVO细胞株凋亡的影响,以及舒林酸作用后的该细胞基因表达谱改变.方法:应用透射电镜,流式细胞仪观察舒林酸作用48 h、72 h对LOVO细胞凋亡的影响;基因芯片法检测舒林酸作用前后LOVO细胞的差异表达基因.结果:经舒林酸处理后细胞有典型的凋亡小体形成:经舒林酸0.6、0.9、1.2 mmo1/L作用后,细胞凋亡率与对照组比较明显升高(48h:4.2±1.04,4.26±0.28,7.51±2.09 vs 1.81±0.9l:72 h:6.21±0.56,7.48±1.45,10.40±1.30 vs 2.06±1.43:均P<0.05).与含有17101个cDNA的基因芯片杂交.筛选出差异表达基因1O13条,其中178条为凋亡相关基因(表达上调82条,下调96条),占所有差异表达基因的17.87%.结论:舒林酸具有诱导LOVO细胞发生凋亡的作用.上调或下调某些凋亡相关基因的表达可能是其诱导凋亡的分子机制之一.     

Sarcolemmal Na+/H+ exchanger activity and expression in human ventricular myocardium

OBJECTIVES: To determine sarcolemmal Na+/H+ exchanger (NHE) activity and expression in human ventricular myocardium. BACKGROUND: Although the sarcolemmal NHE has been implicated in various physiological and pathophysiological phenomena in animal studies, its activity and expression in human myocardium have not been studied. METHODS: Ventricular myocardium was obtained from unused donor hearts with acute myocardial dysfunction (n = 5) and recipient hearts with chronic end stage heart failure (n = 11) through a transplantation program. Intracellular pH (pHi) was monitored in enzymatically isolated single ventricular myocytes by microepifluorescence. As the index of sarcolemmal NHE activity, the rate of H+ efflux at a pHi of 6.90 J(H6.9)) was determined after the induction of intracellular acidosis in bicarbonate-free medium. Na+/H+ exchanger isoform 1 (NHE1) expression in ventricular myocardium was determined by immunoblot analysis. RESULTS: Human ventricular myocytes exhibited readily detectable sarcolemmal NHE activity after the induction of intracellular acidosis, and this activity was suppressed by the NHE1-selective inhibitor HOE-642 (cariporide) at 1 micromol/L. Sarcolemmal NHE activity of myocytes was significantly greater in recipient hearts (JH6.9 = 1.95+/-0.18 mmol/L/min) than it was in unused donor hearts (J(H6.9 = 1.06+/-0.15 mmol/L/min). In contrast, NHE1 protein was expressed in similar abundance in ventricular myocardium from both recipient and unused donor hearts. CONCLUSIONS: Sarcolemmal NHE activity of human ventricular myocytes arises from the NHE1 isoform and is inhibited by HOE-642. Sarcolemmal NHE activity is significantly greater in recipient hearts with chronic end-stage heart failure than it is in unused donor hearts, and this difference is likely to arise from altered posttranslational regulation.     

Increased expression of cytoskeletal, linkage, and extracellular proteins in failing human myocardium

Experimental studies have shown that in hypertrophy and heart failure, accumulation of microtubules occurs that impedes sarcomere motion and contributes to decreased ventricular compliance. We tested the hypothesis that these changes are present in the failing human heart and that an entire complex of structural components, including cytoskeletal, linkage, and extracellular proteins, are involved in causing functional deterioration. In explanted human hearts failing because of dilated cardiomyopathy (ejection fraction 相似文献   

结直肠息肉水通道蛋白3、4的表达

目的:观察水通道蛋白(aquaporin,AQP)3、4蛋白在结直肠息肉中的表达.方法:选择结直肠息肉患者103例,肠镜下收集115个息肉组织样本和10例正常人结直肠黏膜组织样本,采用免疫组织化学方法检测AQP3、4的蛋白表达.结果:AQP3、4蛋白在人结直肠黏膜上皮细胞呈阳性表达,均表达在细胞的基底部与侧面.AQP3、4蛋白在炎性息肉中的表达均明显高于正常组,差异有显著性意义(P<0.01,P<0.05);增生性息肉AQP3蛋白表达低于正常组,差异有显著性意义(P<0.01);腺瘤AQP4蛋白表达低于正常组,差异有显著性意义(P<0.01).AQP3与AQP4在结直肠息肉及正常结直肠黏膜中的表达呈正相关(r=0.61,P=0.000).结论:AQP3、4蛋白在结直肠息肉中存在异常表达,二者之间呈正相关.     

Loss of myeloid-related proteins 8 and myeloid-related proteins 14 expression in human esophageal squamous cell carcinoma correlates with poor differentiation

AIM: To study the expression of myeloid-related proteins(MRP)8 and myeloid-related proteins(MRP)14 in human esophageal squamous cell carcinoma and to investigate if there was any correlation between MRP8 and MRP14 expression level and histopathological grade in these tumors. METHODS: In this study, 65 cases of advanced esophageal squamous cell carcinoma were assessed for MRP8 and MRP14 expression using immunohistochemistry. Statistical analysis was performed for the comparison of MRP8 and MRP14 expression in normal and tumor tissues, and their relationship with clinicopathological features. RESULTS: Reduced or absent expression of MRP8 and MRP14 was observed in esophageal squamous cell carcinoma, with a significant difference between tumor tissues and normal tissues (P<0.01 and P<0.01 for MRP8 and MRP14, respectively). Poorly differentiated tumors presented a greater decrease than well and moderately differentiated tumors, with a correlation between their protein level and histopathological grading (P<0.001 and P<0.001, respectively). However, no significant association was found between MRP8 and MRP14 expression and age or gender (P>0.05). CONCLUSION: These findings suggest that the decreased expression of MRP8 and MRP14 might play an important role in the pathogenesis of human esophageal squamous cell carcinoma, being particularly associated with poor differentiation of tumor cells.     

癫痫大鼠海马CA3区凋亡相关蛋白表达及意义

目的探讨癫痫大鼠神经元凋亡的分子机制。方法将SD大鼠分为观察组36只和对照组12只,观察组腹腔注射海人藻酸（KA）制作癫痫模型,对照组腹腔注射等量生理盐水。制模3、6、12h及1、3d采用免疫印迹法检测两组海马CA3区凋亡相关蛋白p-c-Jun、FasL、Bax、Bcl-2的表达;制模7d后采用TUNEL染色法检测CA3区神经元凋亡情况。结果制模6、12h观察组胞核内c-Jun的磷酸化和表达、胞质中FasL表达均明显高于对照组（P均〈0.05）;制模6h时Bax的表达急剧增加,而Bcl-2蛋白表达却明显降低,P均〈0.05;制模7d后CA3区每1mm长度范围内TUNEL阳性细胞数为（177.0±24.7）个,对照组为（21.4±6.8）个,两组相比P〈0.05。结论c-Jun介导的核通路和Bcl-2介导的非核通路共同参与了大鼠海马神经元的凋亡过程。     

脾胃湿热证胃病患者胃黏膜细胞凋亡基因相关蛋白的表达

[目的]探讨脾胃湿热证胃病患者胃黏膜细胞凋亡基因相关蛋白的表达。[方法]选取脾胃湿热证胃病患者70例,检测胃黏膜Fas、p53、增殖细胞核抗原(PCNA)、Bcl-2凋亡基因相关蛋白。并与70例脾胃虚寒证胃病患者进行对照。[结果]脾胃湿热证以糜烂性胃炎多见(58.6%),而脾胃虚寒证以萎缩性胃炎多见(22.9%)。脾胃湿热证患者Fas、p53表达明显高于脾胃虚寒证患者,阳性率分别为74.3%、75.7%和55.7%、64.3%(P<0.05),而PCNA、Bcl-2表达则与脾胃虚寒证患者差异无统计学意义。[结论]脾胃湿热证胃病患者胃黏膜细胞有促凋亡基因相关蛋白的过度表达。     

Expression of galectins-1 and -3 correlates with defective mononuclear cell apoptosis in patients with juvenile idiopathic arthritis

OBJECTIVE: Juvenile idiopathic arthritis (JIA) is characterized by hyperplasia of synovial cells and accumulation of mononuclear inflammatory infiltrates, which are locally maintained through a balance between cell proliferation and apoptosis. Although defective clearance of activated T cells in RA joints has been explained by alterations of the Fas-Fas ligand system, this has not been confirmed in synovial tissue of patients with JIA. We evaluated the relation between expression of galectin-1 (Gal-1) and galectin-3 (Gal-3) (beta-galactoside-binding proteins with pro- and anti-apoptotic properties, respectively) and the apoptosis and proliferation rates of infiltrative lymphocytes in synovial tissue of patients with JIA. METHODS: Using slide cytometry and in situ end labeling we observed dysregulated apoptosis of infiltrating mononuclear cells within the synovial tissue of patients with JIA. RESULTS: Patients with pauciarticular JIA showed minimal apoptosis, high Bcl-2 expression, and high or normal proliferation rates, while patients with polyarticular disease showed the lowest apoptotic indexes, accompanied by low Bcl-2 expression and low proliferation rates. We found that Gal-1 expression is downregulated and Gal-3 expression is upregulated in synovial tissue from patients with JIA. CONCLUSION: In patients with polyarticular JIA, accumulation of inflammatory cells is mainly due to downregulated apoptosis, whereas in patients with pauciarticular disease the process results from increased proliferation. Defective mononuclear apoptosis in synovial inflammatory infiltrates from patients with JIA could be explained in part by decreased Gal-1 and increased Gal-3 expression.     

Transfection of apoptosis related gene Fas ligand in human hepatocellular carcinoma cells and its significance in apoptosis

AIM: To evaluate the expression of apoptosis related gene Fas ligand (FasL) in human hepatocellular carcinoma (HCC) cells HepG2 and its significance in apoptosis. METHODS: Levels of soluble Fas ligand (sFasL) in a group of patients with hepatitis B virus (HBV)-induced chronic hepatitis, HBV-positive liver cirrhosis and HCC were evaluated. In a further study, the recombinant eukaryotic expression plasmid pcDNA3.1hisB-FasL was transfected into HCC cells HepG2 by lipofection, and then soluble FasL was examined in the supernatant of culture cells by EIA, FasL expression in HepG2 cells was detected by immuohistochemistry. After being stained by annexin V and propidium iodine, cells were passed through a flow cytometer and examined by a fluorescence microscope and a laser scanning microscope. RESULTS: The sFasL levels were significantly lower in patients with HCC when compared to the patients with hepatitis or liver cirrhosis. In comparison with untransfected cells, the soluble FasL could be detected in the supernatant of transfected cells. FasL was expressed on the membranes and cytoplasm of transfected cells. The apoptotic cell rate was 36.30% in transfected cells, and was 11.53% in untransfected cells. Moreover, the different stage of apoptotic cells could be distinguished by annexin V and propidium iodine staining. CONCLUSION: Fas ligand is an apoptotic pathway of HCC cells.