细胞凋亡机制研究进展

细胞凋亡是细胞生命活动中的基本现象,是当今生命科学研究的热点。文章通过检索国内外主要数据库,对细胞死亡受体途径、线粒体途径及交织旁路途径进行简要综述。文章可为后续该领域研究提供借鉴,更好的解决实际问题。     

金黄色葡萄球菌对小尾寒羊乳腺组织TLR2表达的影响

Toll样受体能够识别细菌等病原微生物及介导炎症反应信号通路,在先天免疫和获得性免疫中发挥着重要作用。为了解Toll样受体2(TLR2)在小尾寒羊正常乳腺组织及由金黄色葡萄球菌引起的乳腺炎乳腺组织中的表达情况,探讨TLR2在金黄色葡萄球菌乳腺炎致病过程中的作用机制及乳腺上皮细胞在乳腺免疫防御中所起的作用,采用qRT-PCR技术和免疫组织化学染色(IHC)法检测了正常小尾寒羊及金黄色葡萄球菌乳腺炎病理模型小尾寒羊乳腺组织中TLR2基因mRNA及其蛋白的表达情况。结果显示,小尾寒羊正常乳腺组织、金黄色葡萄球菌感染乳腺组织均有TLR2 mRNA及其蛋白表达;但金黄色葡萄球菌感染后乳腺组织中TLR2基因及TLR2蛋白显著高于正常乳腺组织,且感染后48 h TLR2 mRNA和TLR2蛋白相对表达量最高(P0.05),96 h TLR2 mRNA和蛋白相对表达量较48 h显著降低(P0.05),正常对照组TLR2的相对表达量最低。通过免疫组织化学染色发现,正常乳腺组织中TLR2蛋白主要定位于乳腺腺泡上皮,而感染金黄色葡萄球菌后乳腺组织中TLR2蛋白主要表达在乳腺腺泡腔中脱落的乳腺上皮细胞和以淋巴细胞为主的炎性细胞上。结果表明,乳腺感染金黄色葡萄球菌后,乳腺上皮细胞是病原菌作用的靶标,通过上调表达TLR2识别病原菌,激发先天免疫。     

5-HT及5-HT1A受体在不同妊娠阶段大鼠子宫中的分布

 【目的】研究5-羟色胺（5-hydroxytryptamine,5-HT）及5-HT1A受体在SD大鼠妊娠期子宫中的分布情况和变化规律。【方法】选取均为正常妊娠的30 只雌性SD大鼠分为妊娠3 d、妊娠5 d、妊娠7 d、妊娠13 d、妊娠19 d及产后第1天6组,处死各组大鼠,取子宫制作石蜡切片,经免疫组织化学SP 法染色后,进行观察分析。【结果】5-HT及5-HT1A受体免疫阳性产物广泛存在于子宫内膜上皮细胞、子宫腺上皮细胞、血管内皮细胞、基质细胞、蜕膜细胞、免疫细胞及肌纤维中;5-HT在妊娠7 d和妊娠13 d着色最深,5-HT1A受体在妊娠13 d着色最深。5-HT及5-HT1A受体免疫阳性产物相对表达量的T检验表明,子宫内膜5-HT在妊娠7 d和妊娠13 d的表达较妊娠3 d、妊娠5 d和产后极显著的增加（P＜0.01）,较妊娠19 d显著增加（P＜0.05）;子宫肌层5-HT在妊娠19 d的表达较妊娠7 d显著减少（P＜0.05）,较妊娠13 d极显著的减少（P＜0.01）。子宫内膜5-HT1A受体在妊娠13 d较妊娠3 d、妊娠5 d、妊娠19 d及产后极显著的增加（P＜0.01）,较妊娠7 d显著增加（P＜0.05）;子宫肌层5-HT1A受体在妊娠13 d较妊娠各个时期极显著增加（P＜0.01）。5-HT和5-HT1A受体在妊娠期子宫中的表达,具有极显著的正相关性。【结论】5-HT和5-HT1A受体在妊娠期子宫中的表达具有一定规律,5-HT通过5-HT1A受体参与妊娠的调节。     

红景天提取物对缺氧诱导的肉鸡肺动脉高压综合症内皮素-1及其受体基因表达的影响

为了探讨不同红景天提取物添加量对高原缺氧条件下肉鸡血浆内皮素水平、心室内皮素-1( ET-1)及其受体mRNA表达水平的影响,将450只1日龄健康AA肉仔鸡随机分为5组,分别饲喂在基础日粮中添加质量分数为0、0.1%、0.15%、0.2%和0.4%红景天水提物干粉的试验日粮,进行为期42 d的饲养试验。结果表明,与对照组相比,在第28和42天时, 0.2%和0.4%红景天组肉鸡血清ET-1水平、左右心室中 ET-1的mRNA表达量显著降低,右心室ER_AR的mRNA表达量显著升高; 42 d心脏指数显著降低。在第28和42天,0.2%和0.4%红景天组肉鸡血清ET-1水平和右心室ET_AR的mRNA表达量显著高于0.1%和0.15%红景天组,而右心指数和 ET-1 mRNA表达量显著低于0.1%和0.15%红景天组。说明饲喂红景天提取物能够改善高原缺氧条件下肉鸡肺动脉高压综合症,但存在计量依懒性。     

Effects of She Xiang Bao Xin Wan (SXBXW) on the proliferation of primary cultured human umbilical artery vascular smooth muscle cells induced by endothelin-1

AIM: To observe the effects of She Xiang Bao Xin Wan (SXBXW) of Chinese patent medicine on the proliferation of primary cultured vascular smooth muscle cells (VSMCs) from human umbilical artery and stimulated by endothelin-1 (ET-1) in vitro. METHODS: The proliferation cell models of primary cultured VSMCs were established by ET-1 stimulation. Six groups in the experiment were divided into control group; ET-1 group; ET-1+SXBXW 0.25 g/L; ET-1+SXBXW 0.5 g/L; ET-1+SXBXW 1.0 g/L and ET-1+SXBXW 2.0 g/L groups, respectively. The proliferation induced by ET-1 and the suppression mediated by SXBXW on VSMCs were measured by MTT method. The inhibitory rate and the cytotoxicity of SXBXW were detected by lactate dehydrogenase colorimetry and trypan blue exclusion tests. The effect of ET-1 and SXBXW on the cell proliferation cycle was analyzed by flow cytometry. RESULTS: Compared to control group, ET-1 significantly enhanced the proliferation of VSMCs (P<0.01). However, a certain dose of SXBXW inhibited effectively the proliferation of VSMCs induced by ET-1 in a dose-dependent manner (P<0.01). Meanwhile, SXBXW showed no influenced on both the number of living cells and the release of lactate dehydrogenase, although it inhibited the proliferation of VSMCs, indicating that SXBXW was no cytotoxicitic effect on VSMCs. ET-1 enhanced the proliferation of VSMCs by means of promoting the transition of the cell cycle from G1 phase to S phase. However SXBXW significantly inhibited the proliferation mediated by ET-1. CONCLUSION: SXBXW plays the role in suppressing VSMCs proliferation induced by ET-1. The mechanism may be involved in blocking the cell cycle from G1 phase into S phase.     

PDGFRs expression in dogs affected by malignant oral melanomas: correlation with prognosis

Canine malignant melanoma (CMM) is the most common canine oral tumour, and up to 70–75% of dogs in stage II–III die within 1 year after surgery. The purpose of this study was to evaluate the expression of platelet‐derived growth factors receptors (PDGFR)‐α and ‐β in stage II and III CMMs and to correlate it with prognosis. PDGFRs expression was evaluated by immunohistochemistry on 48 cases of formalin‐fixed CMM samples and correlated with clinical–pathological findings and outcome after surgery. PDGFRs co‐expression was observed in 37.5% of cases. Positivity for PDGFR‐α and ‐β receptor was present in 54.2 and 47.9% of cases, respectively. Ki67 values >19.5% were ascertained in 66.7% of cases. Statistical analysis showed that PDGFRs co‐expression and Ki67 values > 19.5% were both associated with worse prognosis. PDGFRs expression suggests a role in the pathogenesis and progression of CMM, and α and β co‐expression appears to be associated to worse prognosis.     

Seasonal or pathological findings? Morphofunctional characteristics of the equine endometrium during the autumn and spring transition

The deep anoestrous phase in winter is part of the anovulatory season in mares and is bordered by the autumn and spring transitional periods (ATP/STP). To define an annual time span for effective prognostic biopsy sampling, the aim of this study was to provide a morphofunctional characterization of the endometrium during ATP and STP. To outline both transitional periods, endometrial specimens were taken in September, October and November (n = 76) as well as February, March and April (n = 184) with the requirement of a detailed clinical documentation. Tissue samples were examined histologically with special emphasis on the functional endometrial morphology. Additionally, an immunohistochemical evaluation was performed on selected specimens regarding the expression of oestrogen receptor α, progesterone receptor and Ki67‐antigen. An absent to low endometrial activity was ascertained in more than 60% of all specimens from late October onwards, whereas a comparably lacking or low activity in STP was observed until early April. Approximately 30% (ATP) to 22% (STP) of all samples exhibited a predominantly “irregular” endometrial differentiation. During the transitional periods, the clinically evaluated ovarian status (transrectal palpation, transrectal ultrasonography and/or serum progesterone and oestrogen analyses) and the endometrial functional morphology were in accordance with approximately 70% of all cases. The expression of steroid hormone receptors and Ki67‐antigen was generally low. Given that endometrial maldifferentiations were frequently found during ATP and STP, its occurence might display a characteristic and physiological feature of the transitional periods. Regarding the functional endometrial morphology, a diagnostic biopsy sampling should therefore be performed between late April and before September.     

昆虫类胰岛素及其功能研究进展

胰岛素是一类生物体内在进化上非常保守的具有调控代谢、生长、发育、生殖和寿命等多种功能的肽类激素。在昆虫中,以多基因家族编码的类胰岛素为主,在结构上与脊椎动物胰岛素同源。近年来,有关昆虫类胰岛素及其信号通路等方面已有较多研究,特别是对黑腹果蝇的研究,为人类胰岛素相关疾病诊断与治疗提供了较好的试验模型。本文主要介绍昆虫类胰岛素及其受体、类胰岛素表达与释放、类胰岛素信号通路及其在调控昆虫生殖、寿命、代谢、生长与发育和翅型分化等生理功能的最新研究进展,为促进其在害虫控制或天敌保护利用等方面的应用提供参考。     

Endothelin-1, endothelin converting enzyme-1 and endothelin receptors in the porcine corpus luteum

Porcine corpora lutea (CL) fail to show a luteolytic response to prostaglandin-F-2α (PGF-2α) (ie, luteolytic sensitivity [LS]) until about day 12-13 of the estrous cycle. Although little is known of the control of LS in any species, endothelin-1 (EDN1) is believed to play a role in LS control in ruminants. Therefore, we measured mRNA and protein expression and examined the cellular localization of EDN1 precursor (pre-pro EDN1, or ppEDN1), EDN-converting enzyme-1 (ECE1), and EDN receptors (A, EDNRA and B, EDNRB) in porcine CLs collected on days 4, 7, 10, 13, and 15 of the estrous cycle to look for differences between CLs displaying (days 13-15) versus those lacking (days 4-10) LS. Abundance of ppEDN1 mRNA was greatest (and significant vs all other days) on day 7 of the cycle, whereas EDN1 protein expression did not vary during the cycle and was localized exclusively to endothelial cells (EC). Abundance of ECE1 mRNA was also greatest on day 7 (vs all other days), but ECE1 protein was significantly elevated on day 10 (vs day 4) and was immunolocalized to ECs and large luteal cells (LLC). Abundance of EDNRA mRNA was also maximal on day 7 (vs all other days) of the cycle, whereas EDNRA protein expression was not significantly changed during the cycle and was observed in LLCs, ECs, and small luteal cells (SLC). On day 13, EDNRB mRNA was significantly decreased (versus day 7). Expression of EDNRB protein was decreased on day 10 (versus all other days), and on days 13-15 (vs day 4), and was primarily localized to ECs. In conclusion, the observed elevation in ECE1 protein concentrations on day 10 and the presence of EDNRA on LLC suggests a possible role for EDN1 (resulting from the actions of ECE1) acting via EDNRA in the control of LS in the pig.     

Neonicotinoids-from zero to hero in insecticide chemistry

In recent years, neonicotinoids have been the fastest-growing class of insecticides in modern crop protection, with widespread use against a broad spectrum of sucking and certain chewing pests. As potent agonists, they act selectively on insect nicotinic acetylcholine receptors, their molecular target site. The discovery of neonicotinoids can be considered as a milestone in insecticide research and facilitates greatly the understanding of the functional properties of insect nicotinic acetylcholine receptors. Because of the relatively low risk for non-target organisms and environment, the high target specificity of neonicotinoid insecticides and their versatility in application methods, this important class has to be maintained globally for integrated pest management strategies and insect resistance management programmes. This review comprehensively describes particularly the origin, structure and bonding as well as associated properties of neonicotinoid insecticides.