Effect of CHOP expression knock-down on apoptosis of renal tubular epithelial cells

AIM:To study the effect of C/EBP homologous protein (CHOP) on the apoptosis of renal tubular epithelial HK2 cells. METHODS:The serum mRNA levels of CHOP in the patients with acute kidney injury and healthy controls were detected by qPCR. In vitro, renal tubular epithelial HK2 cells were divided into control group, negative group (transfected with negative control siRNA), si-CHOP group (transfected with CHOP siRNA), and induced by transforming growth factor-β1 (TGF-β1). The viability of the cells was measured by MTT assay, and the apoptotic rate was analyzed by flow cytometry. The protein levels of nuclear antigen Ki-67, proliferating cell nuclear antigen (PCNA), caspase-3 and cleaved caspase-3 were determined by Western blot. RESULTS:Compared with the healthy controls, the serum mRNA levels of CHOP in the patients with acute kidney injury were increased significantly (P<0.05). Transfection with CHOP siRNA significantly decreased the expression of CHOP in the renal tubular epithelial HK2 cells (P<0.05). Knock-down of CHOP expression by siRNA significantly increased the viability of renal tubular epithelial HK2 cells (P<0.05), decreased the apoptotic rate (P<0.05), increased the expression of Ki-67 and PCNA (P<0.05), and down-regulated the protein level of cleaved caspase-3 (P<0.05). CONCLUSION:The serum mRNA levels of CHOP were increased in the patients with acute kidney injury. Knock-down of CHOP expression inhibits the apoptosis of renal tubular epithelial cells by regulating the expression of proliferation-and apoptosis-related proteins.     

大白菜游离小孢子培养技术高效体系的研究

以大白菜吉红82、#534DH 群体及#438 群体为试材，研究了利用细胞破碎仪机械提取小孢子与人工挤压提取小孢子对大白菜游离小孢子活力及提取量的影响。结果表明：机械提取替代人工挤压可在短时间内同时提取多份样品，并可快速调整小孢子的培养浓度。收集40 个适期花蕾于5 mL 离心管内，3 000 r·min-1 破碎10 s，将提取的小孢子定容于25 mL NLN-13 培养基，可确保小孢子浓度在适宜培养范围内，并成功诱导胚胎发生。     

Correlation between Mnk2 protein expression and prognosis of patients with esophageal squamous cell carcinoma

AIM: To investigate the protein expression of mitogen-activated protein kinase-interacting kinase-2 (Mnk2) and its prognostic effect in the patients with resected esophageal squamous cell carcinoma (ESCC). METHODS: A total of 86 informative patients with surgically resected ESCC and 54 normal esophageal tissues were enrolled. Western blot and immunohistochemistry (IHC) were utilized to assess the protein expression of Mnk2, and its correlation with prognosis was statistically analyzed by the methods of Kaplan-Meier curve and Cox proportional hazard mode. RESULTS: The protein expression of Mnk2 was elevated in most of tumor tissues compared with the adjacent tissues. Clinicopathologic analysis showed that Mnk2 expression was significantly correlated with the TNM stage (P<0.05). Both disease-free survival (DFS) and overall survival (OS) of Mnk2 over-expression patients were shorter than those in Mnk2 negative expression group. Multivariate analysis confirmed that Mnk2 expression, as an independent and significant factor for both DFS and OS, predicted a poor prognosis of the patients with resected ESCC (P<0.05). CONCLUSION: The expression of Mnk2 was significantly related to the TNM stages, and might be a novel predictor for prognosis in ESCC.     

暗期短暂远红光处理对南瓜幼苗生长、细胞形态和激素含量的影响

【目的】研究暗期前短暂远红光处理对南瓜幼苗生长形态、组织细胞形态和相关激素水平的影响,为远红光在农业上的应用提供理论依据。【方法】以南瓜品种‘日本雪松’为试验材料,分别在暗期前给予2（T1）、4（T2）、6（T3）、8（T4）、10（T5）和12（T6）mmol·m^-2·d^-1的远红光处理,以无远红光处理为对照（CK）,测定植株生长形态下胚轴细胞形态以及生长素（IAA）、玉米素（ZT）、赤霉素（GA₃）与油菜素内酯（BR）含量。【结果】在暗期短时外施远红光能显著提高南瓜幼苗下胚轴长度和株高,对植株茎粗,地上、地下部干/鲜重无显著影响;2、4、6、8、10和12 mmol·m^-2·d^-1远红光处理的下胚轴薄壁细胞轴向长度分别比CK显著增加34.6%、20.7%、31.3%、25.6%、32.8%和20.9%;下胚轴厚角组织厚度分别比CK显著增加19.6%、22.4%、21.2%、23.9%、19.6%和28%;经暗期前远红光处理后,南瓜幼苗根中生长素（IAA）含量,下胚轴中生长素（IAA）、赤霉素（GA₃）、玉米素（ZT）含量,子叶中生长素（IAA)、赤霉素（GA₃）、油菜素内酯（BR）含量以及真叶中生长素（IAA）与油菜素内酯（BR）含量均得到显著提高。【结论】暗期前短时远红光处理可能通过提高激素含量,进而改变细胞形态,促进下胚轴伸长生长。     

红颈常室茧蜂雌性生殖系统及卵巢管形态学观察

利用光学显微镜和透射电镜观察红颈常室茧蜂Peristenus spretus Chen et van Achterberg雌性生殖系统结构、卵巢发育和卵子发生、卵子超微结构，并对15℃和23℃饲养条件下不同日龄的雌蜂卵巢管长度、卵巢管内卵室大小与成熟度进行了比较，揭示了该茧蜂雌性生殖系统结构与特征。结果表明：1）红颈常室茧蜂生殖系统结构主要包括一对卵巢、2条输卵管、中输卵管等；2）雌成虫在羽化前期（1～3 d）卵巢内的成熟卵粒较少，卵巢管内含有大量的卵原细胞，卵子内充满了大量的脂滴，中后期（5～11 d）随着脂肪体的降解吸收，卵子内逐渐新生一些线粒体、高尔基体等细胞器，其内存在滋养细胞、卵母细胞，并且滋养细胞无细胞膜存在。3）同一温度不同日龄红颈常室茧蜂卵粒数、成熟卵子数均差异显著，23℃下红颈常室茧蜂每条卵巢管内的日均卵子数20.70粒，显著高于15℃的日均卵子数18.65粒。     

龙须菜细胞壁多糖对硼的吸附性能研究

为研究龙须菜(Gracilaria lemaneiformis)细胞壁多糖对硼的吸附作用机制及官能团之间的交互作用,本试验分别采用电感耦合等离子发射光谱(ICP-OES)和傅里叶变换红外光谱(FTIR)技术对其细胞壁多糖组分在吸附试验中进行硼的测定和表征。结果表明,细胞壁去琼胶后,硼吸附量减少50.13%,半纤维素去除后,硼吸附量减少21.20%,故可得纤维素吸附量占细胞壁总硼吸附量的28.67%。同时,通过细胞壁不同组分脱硼及硼胁迫后的红外光谱表征结果可知,龙须菜细胞壁及多糖在吸附硼的过程中,羟基、羧基、多糖碳链C-C为硼离子的主要结合位点,其中,琼胶、半纤维素中起主要作用的官能团为羟基、羧基,纤维素中起主要作用的官能团为多糖碳链C-C。本研究结果为进一步探究龙须菜多糖组分与硼的内在结合机制提供了基础依据。     

马链球菌兽疫亚种烯醇化酶对小鼠肺泡巨噬细胞吞噬功能的影响

旨在研究马链球菌兽疫亚种（Streptococcus equi ssp.zooepidemicus，SEZ）烯醇化酶（enolase，Eno）对小鼠肺泡巨噬细胞（RAW264.7）吞噬能力的影响。通过构建原核表达质粒获得重组烯醇化酶（rEno），采用台盼蓝活细胞计数法，判定在不同处理浓度和时间下rEno蛋白对RAW264.7细胞的细胞毒性。将rEno蛋白与RAW264.7细胞共孵育后，用SEZ作用于细胞并检测细胞吞菌数量，判断RAW264.7细胞对SEZ的吞噬活性。进一步通过活细胞稳定同位素标记技术（SILAC）和蛋白质谱分析技术（LC-MS/MS），筛选到RAW264.7细胞中可能与SEZ Eno存在相互作用的候选蛋白。结果发现，10 μg·mL^-1 rEno蛋白处理对RAW264.7细胞有明显的细胞毒性，且10 μg·mL^-1 rEno蛋白处理RAW264.7细胞2和4 h可显著抑制其对SEZ的吞噬作用（P<0.01、P<0.05）。初步筛选到RAW264.7细胞中动力蛋白激活蛋白亚单位蛋白（dynactin subunit protein 2，Dctn）、整合素α-M蛋白（integrin alpha-M）等17种可能与Eno发生互作的蛋白。本研究获得了rEno重组表达蛋白，发现rEno可减少RAW264.7细胞对SEZ的吞噬，互作蛋白的初步筛选也为进一步揭示Eno在SEZ抗吞噬中的作用机制奠定了基础。     

Vitamin C enhanced myocardial differentiation of dedifferentiated fat cells

AIM: In order to observe the myocardial differentiation capacity of the dedifferentiated fat (DFAT) cells treated with vitamin C in vitro. METHODS: DFAT cells were dedifferentiated from the mature rat adipocytes with ceiling adherent culture. The DFAT cells of passage 3 were used in the study. Vitamin C and/or neonatal rat heart tissue lysate were added into the culture medium to induce myocardial differentiation for 3 weeks. The cell morphology was observed under microscope. The myocardial-specific markers, such as cTnT, GATA-4 and NKx2.5, were examined by the methods of immunofluorescence, PCR and Western blot. RESULTS: Mature rat adipocytes dedifferentiated into fibroblast-like DFAT cells after ceiling adherent culture. The DFAT cells spontaneously differentiated into cardiomyocyte-like cells under normal culture condition with a low incidence. After treated with neonatal rat heart cell lysate, the DFAT cells became cardiomyocyte-like cells that had bigger size, longer shape and myotubule-structure. The expression of cTnT, GATA-4 and NKx2.5 was remarkably increased at both mRNA and protein levels as compared with the normal cultured DFAT cells. The expression of cTnT, GATA-4 and NKx2.5 was further increased in DFAT cells after treating with vitamin C. No spontaneous beating cell was observed. CONCLUSION: Vitamin C enhances the differentiation of DFAT cells into cardiomyocyte-like cells.