腐食酪螨在不同温度和营养条件下生长发育的比较研究

在12.5℃、15℃、20℃、25℃和30℃恒温下,用啤酒酵母粉和玉米粉为饲料,测定了不同温度和饲料条件下腐食酪螨Tyrophagus putrescentiae各个发育阶段和世代的发育历期,获得其在各条件下的发育起点温度和有效积温。结果表明,在本文的实验温度范围内,该螨的发育历期与温度呈负相关,即随着温度的升高发育历期缩短。在各发育阶段不同饲料条件下发育起点温度和有效积温都有所差异。用啤酒酵母粉作饲料时,腐食酪螨的全世代历期为48.04天（12.5℃下）和8.41天（30℃下）,发育起点温度为10.18℃,有效积温为155.44 d·℃; 用玉米粉作饲料时,全世代历期为78.79天（12.5℃下）和10.77天（30℃下）,发育起点温度为10.52℃,有效积温为208.33 d·℃。以成螨体长和体宽为指标,比较了在各温度条件及不同饲料条件对其生长的影响,结果表明不同饲料对螨体大小有显著影响,温度的影响不明显。     

Direct association of RhoA with specific domains of PKC-alpha

Previous studies performed at our laboratory have shown that agonist-induced contraction of smooth muscle is associated with translocation of protein kinase C (PKC)- and RhoA to the membrane and that this interaction is due to a direct protein-protein interaction. To determine the domains of PKC- involved in direct interaction with RhoA, His-tagged PKC- proteins of individual domains and different combinations of PKC- domains were used to perform in vitro binding assays with the fusion protein glutathione-S-transferase (GST)-RhoA. Coimmunoprecipitation was also performed using smooth muscle cells transfected with truncated forms of PKC- in this study. The data indicate that RhoA directly bound to full-length PKC-, both in vitro (82.57 ± 15.26% above control) and in transfected cells. RhoA bound in vitro to the C1 domain of PKC- [PKC- (C1)] (70.48 ± 20.78% above control), PKC- (C2) (72.26 ± 29.96% above control), and PKC- (C4) (90.58 ± 26.79% above control), but not to PKC- (C3) (0.64 ± 5.18% above control). RhoA bound in vitro and in transfected cells to truncated forms of PKC-, PKC- (C2, C3, and C4), and PKC- (C3 and C4) (94.09 ± 12.13% and 85.10 ± 16.16% above control, respectively), but not to PKC- (C1, C2, and C3) or to PKC- (C2 and C3) (0.47 ± 1.26% and 7.45 ± 10.76% above control, respectively). RhoA bound to PKC- (C1 and C2) (60.78 ± 13.78% above control) only in vitro, but not in transfected cells, and PKC- (C2, C3, and C4) and PKC- (C3 and C4) bound well to RhoA. These data suggest that RhoA bound to fragments that may mimic the active form of PKC-. The studies using cells transfected with truncated forms of PKC- indicate that PKC- (C1 and C2), PKC- (C1, C2, and C3), and PKC- (C2 and C3) did not associate with RhoA. Only full-length PKC-, PKC- (C2, C3, and C4), and PKC- (C3 and C4) associated with RhoA. The association increased upon stimulation with acetylcholine. These results suggest that the functional association of PKC- with RhoA may require the C4 domain. domains; histidine; fusion proteins     

Inducing late phase of infarct protection in skeletal muscle by remote preconditioning: efficacy and mechanism

We have previously demonstrated that remote ischemic preconditioning (IPC) by instigation of three cycles of 10-min occlusion/reperfusion in a hindlimb of the pig elicits an early phase of infarct protection in local and distant skeletal muscles subjected to 4 h of ischemia immediately after remote IPC. The aim of this project was to test our hypothesis that hindlimb remote IPC also induces a late phase of infarct protection in skeletal muscle and that K(ATP) channels play a pivotal role in the trigger and mediator mechanisms. We observed that pig bilateral latissimus dorsi (LD) muscle flaps sustained 46 +/- 2% infarction when subjected to 4 h of ischemia/48 h of reperfusion. The late phase of infarct protection appeared at 24 h and lasted up to 72 h after hindlimb remote IPC. The LD muscle infarction was reduced to 28 +/- 3, 26 +/- 1, 23 +/- 2, 24 +/- 2 and 24 +/- 4% at 24, 28, 36, 48 and 72 h after remote IPC, respectively (P < 0.05; n = 8). In subsequent studies, hindlimb remote IPC or intravenous injection of the sarcolemmal K(ATP) (sK(ATP)) channel opener P-1075 (2 microg/kg) at 24 h before 4 h of sustained ischemia (i.e., late preconditioning) reduced muscle infarction from 43 +/- 4% (ischemic control) to 24 +/- 2 and 19 +/- 3%, respectively (P < 0.05, n = 8). Intravenous injection of the sK(ATP) channel inhibitor HMR 1098 (6 mg/kg) or the nonspecific K(ATP) channel inhibitor glibenclamide (Glib; 1 mg/kg) at 10 min before remote IPC completely blocked the infarct- protective effect of remote IPC in LD muscle flaps subjected to 4 h of sustained ischemia at 24 h after remote IPC. Intravenous bolus injection of the mitochondrial K(ATP) (mK(ATP)) channel inhibitor 5-hydroxydecanoate (5-HD; 5 mg/kg) immediately before remote IPC and 30-min intravenous infusion of 5-HD (5 mg/kg) during remote IPC did not affect the infarct-protective effect of remote IPC in LD muscle flaps. However, intravenous Glib or 5-HD, but not HMR 1098, given 24 h after remote IPC completely blocked the late infarct-protective effect of remote IPC in LD muscle flaps. None of these drug treatments affected the infarct size of control LD muscle flaps. The late phase of infarct protection was associated with a higher (P < 0.05) muscle content of ATP at the end of 4 h of ischemia and 1.5 h of reperfusion and a lower (P < 0.05) neutrophilic activity at the end of 1.5 h of reperfusion compared with the time-matched control. In conclusion, these findings support our hypothesis that hindlimb remote IPC induces an uninterrupted long (48 h) late phase of infarct protection, and sK(ATP) and mK(ATP) channels play a central role in the trigger and mediator mechanism, respectively.     

Post-Operative Plasma Osteopontin Predicts Distant Metastasis in Human Colorectal Cancer

BackgroundThe overall prognosis of colorectal cancer (CRC) patients is unsatisfactory due to cancer metastasis after operation. This study aims to investigate the clinical significance of plasma osteopontin (OPN) levels as minimally invasive, predictive, and surrogate biomarkers for prognosis of CRC patients.MethodsThis randomized study design consists of pre-operative and post-operative plasma samples from a total of 79 patients. We determined plasma levels of OPN by ELISA and examined their correlation with the clinicopathological parameters of CRC patients. The effects of endogenous and exogenous OPN on CRC metastasis were investigated by examination of the effect on regulators of epithelial to messenchymal transition and migration assay.ResultsOur findings demonstrated for the first time the clinical correlation of plasma OPN with metastasis of CRC patients. High post-operative plasma OPN level (>153.02 ng/ml) associated with development of metastasis after curative resection (p<0.001). Moreover, post-operative plasma OPN level correlated with disease-free survival of CRC patients (p=0.009) and was an independent factor for predicting development of metastasis in CRC patients after curative resection (p=0.036). Our in vitro model showed that OPN ectopic expression induced DLD1 cell migration through Snail and Twist1 overexpression and E-cadherin repression, and secretory OPN level enhanced cell migration.ConclusionsThe results of the current study suggest that post-operative plasma OPN correlated with post-operative metastasis, suggesting that it is a potential non-invasive biomarker for the development of future metastasis in CRC patients. In addition, OPN was shown to be involved in the metastatic process and thus inhibition of OPN is a potential therapeutic approach to treat CRC patients.     

A Potent Anticancer Agent of Shikonin Derivative Targeting Tubulin

In this study, a shikonin ester derivative, compound 3g , was selected to evaluate its anticancer activities and we found that compound 3g exhibited better antitubulin activities against the human HepG2 cell line with an IC₅₀ value of 1.097 μM. Furthermore, the inhibition of tubulin polymerization results indicated that compound 3g demonstrated the most potent antitubulin activity (IC₅₀ = 13.88), which was compared with shikonin and colchicine as positive controls (IC₅₀ = 25.28 μM and 22.56 μM), respectively. Compound 3g was simulated to have good binding site with tubulin and arrested the cell cycle at G2/M phase, which also induces apoptosis in HepG2 cells, in which P53 and members of Bcl‐2 protein family were both involved in the progress of apoptosis revealed by western blot. Confocal microscopy observations revealed compound 3g targeted tubulin and altered its polymerization by interfering with microtubule organization. Based on these results, compound 3g functions as a potent anticancer agent targeting tubulin. Chirality 27:274–280, 2015.. © 2015 Wiley Periodicals, Inc.     

蝉虫草样品的分级萃取与化学成分分析

利用索氏萃取技术,依次采用石油醚、乙酸乙酯、丙酮、无水乙醇和甲醇等5种溶剂对蝉虫草纯粉进行分级萃取,运用傅里叶变换红外光谱分析法和气相色谱-质谱联用技术对5级萃取物进行分析鉴定。傅里叶变换红外光谱分析显示萃取物中含有与烯烃类、羧酸类、酯类、醇类和酮类等化合物相关的C-H、C=O、C-O和C=C等官能团。气相色谱-质谱联用技术共鉴定出有机小分子化合物34种,以酯类和脂肪酸类为主,多为碳链长度为15-20的长链脂肪酸及对应的酯,其中十八碳不饱和脂肪酸相对含量高达28.95%;分别存在于两种或以上萃取物中的有机化合物共有11种;仅存于石油醚萃取物中的化合物6种,乙酸乙酯萃取物中3种,丙酮萃取物中2种,无水乙醇萃取物中6种,甲醇萃取物中6种。在一定极性范围内,利用溶剂的极性梯度变化,可实现蝉虫草中活性物质的按极性梯度分离;采用分级萃取技术可有效分离蝉虫草中部分化学成分。鉴定结果充实了蝉虫草中化合物的种类资源,为蝉虫草中活性物质谱图库的完善、构效关系的建立及蝉虫草产品的利用开发提供支撑。     

CYC类基因在被子植物花发育中的研究进展

CYCLOIDEA(CYC)类基因属于TCP基因家族成员,在花发育过程中具有重要作用。CYC类基因在被子植物进化过程中发生基因复制事件,形成CYC1、CYC2和CYC3三大分支,其中CYC2分支成员在花对称性形成方面具有主要调控作用。CYC1和CYC3分支成员开展研究较少。综述了国内外CYC类基因的研究现状及其存在问题,并对CYC类基因的研究前景做了展望。     

MicroRNA-323-3p promotes myogenesis by targeting Smad2

Skeletal muscle is an important and complex organ with multiple biological functions in humans and animals. Proliferation and differentiation of myoblasts are the key steps during the development of skeletal muscle. MicroRNA (miRNA) is a class of 21-nucleotide noncoding RNAs regulating gene expression by combining with the 3′-untranslated region of target messenger RNA. Many studies in recent years have suggested that miRNAs play a critical role in myogenesis. Through high-throughput sequencing, we found that miR-323-3p showed significant changes in the longissimus dorsi muscle of Rongchang pigs in different age groups. In this study, we discovered that overexpression of miR-323-3p repressed myoblast proliferation and promoted differentiation, whereas the inhibitor of miR-323-3p displayed the opposite results. Furthermore, we predicted Smad2 as the target gene of miR-323-3p and found that miR-323-3p directly modulated the expression level of Smad2. Then luciferase reporter assays verified that Smad2 was a target gene of miR-323-3p during the differentiation of myoblasts. These findings reveal that miR-323-3p is a positive regulator of myogenesis by targeting Smad2. This provides a novel mechanism of miRNAs in myogenesis.