昆布多糖对大鼠心肌缺血/再灌注模型葡萄糖调节蛋白-78及半胱氨酸天冬氨酸蛋白水解酶12蛋白表达含量的影响

目的研究昆布多糖(Lam)对大鼠心肌缺血/再灌注(MI/RI)模型中葡萄糖调节蛋白-78(GRP-78)及半胱氨酸天冬氨酸蛋白水解酶12(Caspase 12)蛋白表达含量的影响,探讨其对大鼠心肌是否有保护作用。方法选取32只雄性SD大鼠,随机分为4组:假手术组(sham组)、MI/RI组、Lam低剂量组、Lam高剂量组。采用左冠状动脉结扎法制作大鼠MI/RI模型。酶联免疫吸附试验(ELISA)测定肌酸激酶同工酶MB(CK-MB),比色法测定髓过氧化物酶(MPO)的表达量。应用蛋白质免疫印迹(Western blotting)检测各组中大鼠心肌GRP-78、Caspase 12、B淋巴细胞瘤-2蛋白(Bcl-2)蛋白的表达情况。光镜下观察心肌组织的病理形态学改变。伊文思蓝(Evans)、氯化三苯基四氮唑红(TTC)双染色法测定心肌梗死面积。采用SPSS 21.0软件进行统计分析。结果与MI/RI组相比,低、高剂量组的CK-MB[(93.74±5.37)和(72.71±5.63)和(59.79±9.67)U/L]、MPO[(72.66±3.40)和(58.92±4.88)和(46.06±5.74)U/L]、GRP-78[(1.13±0.02)和(0.81±0.01)和(0.66±0.01)]、Caspase 12[(1.45±0.10)和(0.82±0.06)和(0.62±0.02)]表达显著减少(P0.01),Bcl-2[(1.01±0.04)和(1.19±1.10)和(1.41±0.02)]表达显著升高(P0.01)。与MI/RI组相比,Lam各处理组的心肌组织损伤有不同程度的减轻。与MI/RI组比较,Lam各处理组心肌梗死面积显著减少[(55.36±2.47)%和(46.63±2.10)%和(38.40±2.07)%,P0.05]。结论 Lam能减轻大鼠MI/RI,对MI/RI的心肌有保护作用。其机制可能是Lam抑制GRP-78的过度表达,减轻了由内质网应激介导细胞凋亡途径的激活,下调Caspase 12凋亡通路,增强Bcl-2的表达,从而抑制心肌细胞凋亡。     

Pathophysiologic mechanisms in diabetic kidney disease: A focus on current and future therapeutic targets

Diabetic kidney disease (DKD) is the primary cause of chronic kidney disease around the globe and is one of the main complications in patients with type 1 and 2 diabetes. The standard treatment for DKD is drugs controlling hyperglycemia and high blood pressure. Renin angiotensin aldosterone system blockade and sodium glucose cotransporter 2 (SGLT2) inhibition have yielded promising results in DKD, but many diabetic patients on such treatments nevertheless continue to develop DKD, leading to kidney failure and cardiovascular comorbidities. New therapeutic options are urgently required. We review here the promising therapeutic avenues based on insights into the mechanisms of DKD that have recently emerged, including mineralocorticoid receptor antagonists, SGLT2 inhibitors, glucagon-like peptide-1 receptor agonist, endothelin receptor A inhibition, anti-inflammatory agents, autophagy activators and epigenetic remodelling. The involvement of several molecular mechanisms in DKD pathogenesis, together with the genetic and epigenetic variability of this condition, makes it difficult to target this heterogeneous patient population with a single drug. Personalized medicine, taking into account the genetic and mechanistic variability, may therefore improve renal and cardiovascular protection in diabetic patients with DKD.     

Melatonin activates cell death programs for the suppression of uterine leiomyoma cell proliferation

The circadian nature of melatonin has a protective effect on the progression of female reproductive cancers, including breast and ovarian cancers. However, the effect of melatonin on the growth of uterine leiomyoma is still unclear. In this study, we found that the growth of uterine leiomyoma ELT3 cells was reduced by treatment with melatonin. Treatment with melatonin increased the distribution of sub-G1 phase and increased DNA condensation in ELT3 cells. Melatonin-induced apoptosis and autophagy cell death progression were observed in ELT3 cells. Melatonin exerts a highly selective effect on primary normal human uterine smooth muscle (UtSMC) cells. The UtSMC cell cycle was arrested by melatonin treatment through up-regulation of p21, p27, and PTEN protein expression, but melatonin did not further promote apoptosis program activation. Melatonin reduced cell proliferation in ELT3 cells underlying the activation of melatonin MT1 and MT2 receptors, which in turn down-regulated the Akt-ERK1/2-NFκB signaling pathway. Melatonin reduced ELT3 tumor growth in both xenograft and orthotopic uterine tumor mice models. The extracellular matrix of the tumor was also reduced by melatonin treatment. Taken together, these results suggest that melatonin potentially plays a role in suppression of uterine leiomyoma growth.     

活化转录因子4在心房颤动患者血浆和外周血单核细胞中的表达及与预后的相关性

目的:研究活化转录因子4(ATF4)在心房颤动(AF)患者中的表达,并探讨血浆ATF4对接受射频消融术的AF患者术后复发的预测价值.方法:选取2019年2月-2020年2月于蚌埠医学院第一附属医院首次接受射频消融术治疗的AF患者149例,其中阵发性房颤组(PaAF组)83例,持续性房颤组(PeAF组)66例,并选取同期...     

黄芪多糖对大鼠缺氧/复氧诱导的心肌细胞自噬及凋亡抑制作用的机制探讨

目的：探究黄芪多糖（APS）通过调控高迁移率族蛋白1/Toll样受体4/核转录因子-κB(HMGB1/TLR4/NF-κB)信号通路对大鼠缺氧/复氧（H/R）诱导的心肌细胞自噬及凋亡的抑制作用。方法：建立H9C2心肌细胞H/R损伤模型并分为4组：对照组、H/R组、APS组和HMGB1抑制剂组。CCK-8法和EdU染色法检测细胞增殖能力;酶联免疫吸附试验检测细胞肿瘤坏死因子（TNF）-α、白细胞介素（IL）-1β、IL-6含量;透射电镜观察细胞自噬小体的形成;膜联蛋白V-异硫氰酸荧光素/碘化丙啶（AnnexinV-FITC/PI）双染法检测细胞凋亡;实时定量PCR检测细胞HMGB1、TLR4、NF-κB p65 mRNA表达水平;蛋白免疫印迹法检测细胞HMGB1、TLR4、NF-κB p65、B细胞淋巴瘤-2(Bcl-2)、Bcl-2相关X蛋白（Bax）、含半胱氨酸的天冬氨酸蛋白水解酶-3(caspase-3)、P62、微管相关蛋白1A/1B-轻链3(MAP1LC3,缩写为LC3)-Ⅱ蛋白表达水平。结果：与对照组相比,H/R组细胞增殖能力明显减弱,凋亡及自噬水平明显增加,细胞内可见大量自...     

Changes in ultrastructure of hepatocytes and liver test results before,during, and after treatment with interferon-β in patients with HBeAg-positive chronic active hepatitis

We studied the histological and ultrastructural changes in the liver and alterations in the liver test results before, during, and after treatment with human interferon- from five patients with hepatitis B e antigen-positive chronic active hepatitis. A daily dose of 3×10⁶ to 6×10⁶ units of interferon- was given intravenously for four weeks. The total index of periportal and portal inflammation, intralobular degeneration, and focal necrosis before treatment was decreased significantly six months after treatment (P<0.05). Ultrastructurally, the structure of endoplasmic reticulum was irregularly shaped or fragmentally decreased during treatment, but these disappeared six or 12 months after treatment. Glycogen particles diminished greatly during treatment. The alanine aminotransferase concentrations in these patients increased during treatment. Serum albumin and cholinesterase levels decreased significantly at the fourth week of treatment (P<0.01) and at the third day (P<0.01) to the second week (P<0.05) of treatment, respectively. These results suggest that interferon- injures endoplasmic reticulum and glycogen areas and damages the cholinesterase activity in the early stage of treatment and protein synthesis in patients with hepatitis B e antigen-positive chronic active hepatitis.     

Interactions between calcium waves and action potential-induced calcium transients in guinea pig myocytes

Summary In isolated cardiac muscle, spontaneous Ca²⁺ release from the sarcoplasmic reticulum (SR) occurs and is propagated as a wave by a regenerative Ca²⁺-induced Ca²⁺ release mechanism. We have already reported that this wave is followed by a refractory period. The aim of this study is to investigate whether such a refractory period could also inactivate Ca²⁺ release from the SR triggered by an action potential. Myocytes were enzymatically isolated from guinea pig ventricles and loaded with acetoxymethylester form of fura-2 (fura-2 AM). The membrane potential was recorded with a conventional microelectrode technique, and spatio-temporal changes in fura-2 fluorescence were recorded using a digital TV system. After perfusion with potassium-free Tyrode solution, interactions between fluorescence transients due to propagating waves and action potential-induced fluorescence transients were observed. In this study, the action potentialinduced fluorescence transients could be detected in the next video frame after the propagation of the waves and showed gradual restitution of the transients. In addition, the sum of the fluorescence transients triggered by an action potential and the fluorescence transients due to the waves did not show significant change whenever the preceding waves were propagating. These results show that the interaction between the action potential-induced Ca²⁺ release and the calcium wave-induced Ca²⁺ release from the SR have the following characteristics: (1) For the action potentialinduced Ca²⁺ release, no absolute refractory period was observed 33 msec after the calcium wave. This suggests that the calcium waves can be reset by the action potential. (2) Regardless of whether the two release mechanisms are different, both share a common compartment of Ca²⁺ storage.     

The effect of certain high cardiac output states on dog heart myosin ATPase

This work was done to evaluate the response of cardiac myosin ATPase in the compensated heart subjected to the increased volume work of a high cardiac-output state.Dogs with bilateral femoral arteriovenous fistulas were studied either 14 days (acute arteriovenous fistulas) or a mean of 230 days (chronic arteriovenous fistulas) after construction of the fistulas. Dogs with anemia secondary to repeated bleeding (anemic) were studied 14 days after a high output state was first documented.Calcium-activated myosin adenosine-triphosphatase (ATPase) activity was significantly elevated for the anemic and acute arteriovenous fistula dogs, but the elevations were not significant for myosin from the chronic arteriovenous fistula dogs. In the presence of K⁺ and EDTA, the cardiac myosin ATPase activity was generally elevated for the anemic, less so for the acute arteriovenous fistula and was normal for the chronic arteriovenous fistula.The Ca²⁺ uptake (in the presence of oxalate) by the cardiac sarcoplasmic reticulum was significantly less than normal for all three groups.