化脓隐秘杆菌对奶牛脾脏组织细胞凋亡的影响

目的观察化脓隐秘杆菌自然感染奶牛脾脏组织的病理学变化,并检测组织细胞中Caspase-3、Caspase-8、Caspase-9、Bax和Bcl-2的表达,以确定化脓隐秘杆菌感染对奶牛脾脏组织细胞凋亡的影响。方法筛检2头化脓隐秘杆菌阴性健康奶牛(对照)和5头自然感染化脓隐秘杆菌的奶牛,收集脾脏组织样本,采用本课题组国家发明专利方法,进行石蜡制片和HE染色,观察脾脏组织病理学变化;采用免疫组织化学方法与本课题组国家发明专利方法相结合,检测奶牛脾脏组织中与细胞正负凋亡相关的调节基因Bax和Bcl-2及凋亡通路蛋白Caspase-3、Caspase-8和Caspase-9的表达情况。结果肉眼观察可见化脓隐秘杆菌自然感染奶牛脾脏肿大、柔软,有出血;病理组织学观察可见脾脏组织出血,水肿,淋巴细胞数量减少,有坏死;脾脏淋巴细胞Caspase-3、Caspase-9和Bax表达阳性,与对照组相比,差异有统计学意义(P <0.05),少量淋巴细胞Caspase-8和Bcl-2表达阳性,与对照组相比,差异无统计学意义(P> 0.05)。结论化脓隐秘杆菌能够引起奶牛脾脏淋巴细胞发生坏死和凋亡;可通过调节脾脏中淋巴细胞Bcl-2家族的活性,引起其Bax和Bcl-2比率改变,增加淋巴细胞线粒体内外膜通透性,导致与凋亡相关因子的释放,激活Caspase-9,进一步激活Caspase-3,从而引起脾脏中淋巴细胞发生凋亡。     

3-<i>epi</i>-bufotalin suppresses the proliferation in colorectal cancer cells through the inhibition of the JAK1/STAT3 signaling pathway

Traditional Chinese medicine (TCM) has been increasingly employed in the last decades in China for both preventing and treating a variety of cancers. 3-epi-bufotalin is an active ingredient of TCM “Chanpi” with anti-tumor potential. However, the effect and mechanism of 3-epi-bufotalin on colorectal cancers were not well disclosed. The present study demonstrated that 3-epi-bufotalin could reduce viability, trigger apoptosis, and block the cell cycle at the G₂/M stage in colorectal cancer cell lines HT29, RKO, and COLO205 in vitro. Moreover, 3-epi-bufotalin inhibited the JAK1/STAT3 signaling pathway. These results indicated the anti-proliferation ability of 3-epi-bufotalin in colorectal cancer cells.     

Hypoxia induced apoptosis of rat gastric mucosal cells by activating autophagy through HIF-1α/TERT/mTORC1 pathway

The pathogenesis of high altitude-related gastric mucosal injury remains poorly understood, this study aimed to investigate the role of autophagy in hypoxia-induced apoptosis of rat gastric mucosal cells. Rats were randomized into four groups which were maintained at an altitude of 400 m (P) or received no treatment (H), autophagy inducer rapamycin (H+AI) or autophagy inhibitor 3-MA (H+AB) at an altitude of 4,300 m for 1, 7, 14 and 21 days, respectively, and the morphology, ultrastructure, autophagy, and apoptosis of gastric mucosal tissues were examined. Gastric mucosal epithelial cells CC-R039 were cultured under conditions of normoxia, 2% O2 (hypoxia), or 2% O2+anti-mTORC1 for 0, 24, 48, and 72 h, respectively, and the autophagy and apoptosis were analyzed. CC-R039 cells were transfected with siHIF-1α, siTERT, or siRNA and the autophagy was examined. The results showed that the exposure to hypoxia increased the autophagy and apoptosis of gastric mucosal cells in rats, and apoptosis was aggravated by rapamycin treatment but alleviated by 3-MA treatment. Increased duration of hypoxia from 0 to 72 h could increase the autophagy and apoptosis but decrease the proliferation of gastric mucosal cells. Inhibition of mTORC1 with rapamycin led to further increase in apoptosis and even substantial cell death, and inhibition of HIF- 1α and TERT increased mTORC1 expression and reduced autophagy. Moreover, the inhibition of HIF-1α reduced TERT expression. In conclusion, hypoxia could induce apoptosis of rat gastric mucosal cells by activating autophagy through HIF-1α/TERT/mTORC1 pathway     

Hydroxyoctadecadienoic Acids Regulate Apoptosis in Human THP‐1 Cells in a PPARγ‐Dependent Manner

Macrophage apoptosis, a key process in atherogenesis, is regulated by oxidation products, including hydroxyoctadecadienoic acids (HODEs). These stable oxidation products of linoleic acid (LA) are abundant in atherosclerotic plaque and activate PPARγ and GPR132. We investigated the mechanisms through which HODEs regulate apoptosis. The effect of HODEs on THP‐1 monocytes and adherent THP‐1 cells were compared with other C18 fatty acids, LA and α‐linolenic acid (ALA). The number of cells was reduced within 24 hours following treatment with 9‐HODE (p < 0.01, 30 μM) and 13 HODE (p < 0.01, 30 μM), and the equivalent cell viability was also decreased (p < 0.001). Both 9‐HODE and 13‐HODE (but not LA or ALA) markedly increased caspase‐3/7 activity (p < 0.001) in both monocytes and adherent THP‐1 cells, with 9‐HODE the more potent. In addition, 9‐HODE and 13‐HODE both increased Annexin‐V labelling of cells (p < 0.001). There was no effect of LA, ALA, or the PPARγ agonist rosiglitazone (1μM), but the effect of HODEs was replicated with apoptosis‐inducer camptothecin (10μM). Only 9‐HODE increased DNA fragmentation. The pro‐apoptotic effect of HODEs was blocked by the caspase inhibitor DEVD‐CHO. The PPARγ antagonist T0070907 further increased apoptosis, suggestive of the PPARγ‐regulated apoptotic effects induced by 9‐HODE. The use of siRNA for GPR132 showed no evidence that the effect of HODEs was mediated through this receptor. 9‐HODE and 13‐HODE are potent—and specific—regulators of apoptosis in THP‐1 cells. Their action is PPARγ‐dependent and independent of GPR132. Further studies to identify the signalling pathways through which HODEs increase apoptosis in macrophages may reveal novel therapeutic targets for atherosclerosis.     

ZnO nanoparticle-induced oxidative stress triggers apoptosis by activating JNK signaling pathway in cultured primary astrocytes

It has been documented in in vitro studies that zinc oxide nanoparticles (ZnO NPs) are capable of inducing oxidative stress, which plays a crucial role in ZnO NP-mediated apoptosis. However, the underlying molecular mechanism of apoptosis in neurocytes induced by ZnO NP exposure was not fully elucidated. In this study, we investigated the potential mechanisms of apoptosis provoked by ZnO NPs in cultured primary astrocytes by exploring the molecular signaling pathways triggered after ZnO NP exposure. ZnO NP exposure was found to reduce cell viability in MTT assays, increase lactate dehydrogenase (LDH) release, stimulate intracellular reactive oxygen species (ROS) generation, and elicit caspase-3 activation in a dose- and time-dependent manner. Apoptosis occurred after ZnO NP exposure as evidenced by nuclear condensation and poly(ADP-ribose) polymerase-1 (PARP) cleavage. A decrease in mitochondrial membrane potential (MMP) with a concomitant increase in the expression of Bax/Bcl-2 ratio suggested that the mitochondria also mediated the pathway involved in ZnO NP-induced apoptosis. In addition, exposure of the cultured cells to ZnO NPs led to phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-related kinase (ERK), and p38 mitogen-activated protein kinase (p38 MAPK). Moreover, JNK inhibitor (SP600125) significantly reduced ZnO NP-induced cleaved PARP and cleaved caspase-3 expression, but not ERK inhibitor (U0126) or p38 MAPK inhibitor (SB203580), indicating that JNK signaling pathway is involved in ZnO NP-induced apoptosis in primary astrocytes.     

Cytotoxicity induced by nanobacteria and nanohydroxyapatites in human choriocarcinoma cells

We explored the cytotoxic effects of nanobacteria (NB) and nanohydroxyapatites (nHAPs) against human choriocarcinoma cells (JAR) and the mechanisms of action underlying their cytotoxicity. JAR cells were co-cultured with NB and nHAPs for 48 h, and ultrastructural changes were more readily induced by NB than nHAPs. Autophagy in the plasma of JAR cells were observed in the NB group. The rate of apoptosis induced by NB was higher than that for nHAPs. The expression of Bax and FasR proteins in the NB group was stronger than that for the nHAP group. NB probably resulted in autophagic formation. Apoptosis was possibly activated via FasL binding to the FasR signaling pathway.     

An in vitro study to explore the role of prolylcarboxypeptidase in non-small cell lung cancer

Prolylcarboxypeptidase (PRCP) belongs to the S28 family of proteases, which is also a dipeptidyl peptidase. In this study, we demonstrate the expression pattern of PRCP in Non-small cell lung cancer (NSCLC). We found that the repression of PRCP expression by small interfering RNA successfully inhibited cell proliferation, migration, and invasion. Further, we explored the involvement of PRCP in the regulation of epithelial-mesenchymal transition (EMT). The epithelial marker E-cadherin was significantly increased, meanwhile mesenchymal markers MUC1, vimentin, and SNAIL were markedly decreased in PRCP knockdown cells. Moreover, the downregulation of PRCP in the NSCLC cells induced the expression of apoptosis-related proteins in vitro. We performed RT-PCR in 30 pairs of clinical NSCLC tissues and adjacent non-cancerous tissues, which revealed significantly higher PRCP expression levels in cancer tissues than in adjacent non-cancerous tissues. Collectively the results from our study suggest a possible cancer promotion role of PRCP in NSCLC.