杆状病毒p35蛋白抗凋亡作用及机理

杆状病毒入侵可以诱导昆虫细胞凋亡,作为对抗宿主防御体系的一种策略,病毒自身编码具有抗细胞凋亡活性的蛋白,如p35蛋白和IAP。杆状病毒p35蛋白是一种广泛有效的凋亡抑制因子,能在哺乳纲、昆虫纲和线虫纲中抑制细胞凋亡作用,推测其与细胞凋亡途径上保守的成分Caspase起作用。研究表明,p35蛋白正是通过蛋白酶间的相互作用和p35蛋白的剪切而起作用的。就最近几年在p35蛋白抗凋亡作用机理方面的研究作一综述 。     

Chaperone Stress 70 Protein (STCH) Binds and Regulates Two Acid/Base Transporters NBCe1-B and NHE1

Regulation of intracellular pH is critical for the maintenance of cell homeostasis in response to stress. We used yeast two-hybrid screening to identify novel interacting partners of the pH-regulating transporter NBCe1-B. We identified Hsp70-like stress 70 protein chaperone (STCH) as interacting with NBCe1-B at the N-terminal (amino acids 96–440) region. Co-injection of STCH and NBCe1-B cRNA into Xenopus oocytes significantly increased surface expression of NBCe1-B and enhanced bicarbonate conductance compared with NBCe1-B cRNA alone. STCH siRNA decreased the rate of Na⁺-dependent pH_i recovery from NH₄⁺ pulse-induced acidification in an HSG (human submandibular gland ductal) cell line. We observed that in addition to NBCe1-B, Na⁺/H⁺ exchanger (NHE)-dependent pH_i recovery was also impaired by STCH siRNA and further confirmed the interaction of STCH with NHE1 but not plasma membrane Ca²⁺ ATPase. Both NBCe1-B and NHE1 interactions were dependent on a specific 45-amino acid region of STCH. In conclusion, we identify a novel role of STCH in the regulation of pH_i through site-specific interactions with NBCe1-B and NHE1 and subsequent modulation of membrane transporter expression. We propose STCH may play a role in pH_i regulation at times of cellular stress by enhancing the recovery from intracellular acidification.     

Dabigatran ameliorates airway smooth muscle remodeling in asthma by modulating Yes‐associated protein

Accumulating evidence indicates that thrombin, the major effector of the coagulation cascade, plays an important role in the pathogenesis of asthma. Interestingly, dabigatran, a drug used in clinical anticoagulation, directly inhibits thrombin activity. The aim of this study was to investigate the effects and mechanisms of dabigatran on airway smooth muscle remodeling in vivo and in vitro. Here, we found that dabigatran attenuated inflammatory pathology, mucus production, and collagen deposition in the lungs of asthmatic mice. Additionally, dabigatran suppressed Yes‐associated protein (YAP) activation in airway smooth muscle of asthmatic mice. In human airway smooth muscle cells (HASMCs), dabigatran not only alleviated thrombin‐induced proliferation, migration and up‐regulation of collagen I, α‐SMA, CTGF and cyclin D1, but also inhibited thrombin‐induced YAP activation, while YAP activation mediated thrombin‐induced HASMCs remodeling. Mechanistically, thrombin promoted actin stress fibre polymerization through the PAR1/RhoA/ROCK/MLC2 axis to activate YAP and then interacted with SMAD2 in the nucleus to induce downstream target genes, ultimately aggravating HASMCs remodeling. Our study provides experimental evidence that dabigatran ameliorates airway smooth muscle remodeling in asthma by inhibiting YAP signalling, and dabigatran may have therapeutic potential for the treatment of asthma.     

Diabetes and Cognitive Deficits in Chronic Schizophrenia: A Case-Control Study

Cognitive impairment occurs in both schizophrenia and diabetes. There is currently limited understanding whether schizophrenia with diabetes has more serious cognitive deficits than schizophrenia without diabetes or diabetes only. This study assessed cognitive performance in 190 healthy controls, 106 diabetes only, 127 schizophrenia without diabetes and 55 schizophrenia with diabetes. This study was conducted from January 2008 to December 2010. Compared to healthy controls, all patient groups had significantly decreased total and five index RBANS scores (all p<0.01–p<0.001), except for the visuospatial/constructional index. Schizophrenia with diabetes performed worse than schizophrenia without diabetes in immediate memory (p<0.01) and total RBANS scores (<0.05), and showed a trend for decreased attention (p = 0.052) and visuospatial/constructional capacity (p = 0.063). Schizophrenia with diabetes performed worse than diabetes only in immediate memory (p<0.001) and attention (p<0.05), and showed a trend for decreased total RBANS scores (p = 0.069). Regression analysis showed that the RBANS had modest correlations with schizophrenia’ PANSS scores, their duration of current antipsychotic treatment, and diagnosis of diabetes. Schizophrenia with co-morbid diabetes showed more cognitive impairment than schizophrenia without diabetes and diabetes only, especially in immediate memory and attention.     

一种新的延胡索酸水合酶抗体的制备及功能研究

延胡索酸水合酶(fumarate hydratase,FH)是三羧酸循环(tricarboxylic acid cycle,TCA)中的一个关键性酶。FH的基因突变将导致延胡索酸合酶缺乏症、遗传性平滑肌瘤和肾细胞癌(hereditary leiomyomatosis and renal cell carcinoma,HLRCC)等疾病。FH缺失导致HLRCC分子的确切生物学机制尚不明确。作者将FH基因片段克隆到原核表达载体上,在大肠杆菌中表达GST-FH(400-510)融合蛋白。该融合蛋白为抗原免疫小鼠获得抗体,通过免疫印迹实验证明了该抗体的特异性并发现FH在心脏和肝脏中的含量较高。通过免疫共沉淀实验发现,在大鼠肝脏组织中FH可能与多个蛋白形成蛋白复合物。     

LncRNA MEG3 inhibits the inflammatory response of ankylosing spondylitis by targeting miR-146a

Molecular and Cellular Biochemistry - Ankylosing spondylitis (AS) is a progressive systemic disease characterized by chronic inflammation response of the sacroiliac joint and spine. Long non-coding...     

Phospholipase C inhibits apoptosis of porcine oocytes cultured in vitro

Oocyte apoptosis can be used as an indicator of oocyte quality and development competency. Phospholipase C (PLC) is a critical enzyme that participates in phosphoinositide metabolic regulation and performs many functions, including the regulation of reproduction. In this study, we aimed to explore whether PLC participates in the regulation of apoptosis in porcine oocytes and investigated its possible mechanism. In porcine oocytes, 0.5 μM U73122 (the PLC inhibitor) was considered to be the best concentration to facilitate maturation, and 0.5 μM m-3M3FBS (the PLC activator) was regarded as the most appropriate concentration to inhibit maturation. The percentage of cleavage and blastocysts treated with 0.5 μM U73122 was lower than that of the control group. Furthermore, the percentage of cleavage and blastocysts treated with 0.5 μM m-3M3FBS was higher than that of the control group. The relative PLC messenger RNA (mRNA) expression tested by a quantitative real-time polymerase chain reaction was found to be inhibited by 0.5 μM U73122 or activated by 0.5 μM m-3M3FBS. The relative mRNA abundance of BAK, BAX, CASP3, CASP8, and TP53 and protein abundance of Bak, cleaved caspase-3, caspase-8, and P53 was activated by U73122 or inhibited by m-3M3FBS, while the relative mRNA and protein level of BCL6 showed the opposite trend. The intracellular Ca²⁺ concentration increased and the expression of PLCB1 protein also increased in porcine oocytes when they were cultured with 0.5 μM m-3M3FBS for 44 hours. The abundance of proteins PKCβ and CAMKIIα and the expression of several downstream genes (CDC42, NFATc1, NFATc2, NFκB, and NLK) were activated by m-3M3FBS or inhibited by U73122. Our findings indicate that PLC inhibits apoptosis and maturation in porcine oocytes. The intracellular Ca²⁺ concentration, two Ca²⁺-sensitive proteins, and several downstream genes were positively regulated by PLC.     

糜子EST-SSR分子标记的开发及种质资源遗传多样性分析

基于前期高通量测序结果设计EST-SSR引物, 用于评估国内外不同生态区144份糜子(Panicum miliaceum)种质资源的遗传差异。结果表明, 200对引物中80对呈多态性, 开发效率为40%; 引物分辨率(Rp)为0.67-4.67 (平均值为2.00), 扩增产物大小为50-500 bp。144份材料在80个位点共检测到206个等位变异, 每个位点为2-3个; 多样性指数(I)为0.659 3 (RYW108)-1.087 2 (RYW124), 平均为0.859 9; 多态性信息含量(PIC)为0.222 9 (RYW98)-0.717 2 (RYW124), 平均为0.457 3。基于UPGMA将144份资源划分为3个群组, 其中2个群组主要为北方春糜子区材料, 另一个群组主要为黄土高原春夏糜子区材料。基于Structure (K=4)将材料划分为4个类群, 即2个代表北方资源基因库以及代表黄土高原和国外资源基因库各1个。基于主成分分析将材料聚为7个类群, 划分结果与材料的地理来源一致。     

Genome‐wide selection footprints and deleterious variations in young Asian allotetraploid rapeseed

Brassica napus (AACC, 2n = 38) is an important oilseed crop grown worldwide. However, little is known about the population evolution of this species, the genomic difference between its major genetic groups, such as European and Asian rapeseed, and the impacts of historical large‐scale introgression events on this young tetraploid. In this study, we reported the de novo assembly of the genome sequences of an Asian rapeseed (B. napus), Ningyou 7, and its four progenitors and compared these genomes with other available genomic data from diverse European and Asian cultivars. Our results showed that Asian rapeseed originally derived from European rapeseed but subsequently significantly diverged, with rapid genome differentiation after hybridization and intensive local selective breeding. The first historical introgression of B. rapa dramatically broadened the allelic pool but decreased the deleterious variations of Asian rapeseed. The second historical introgression of the double‐low traits of European rapeseed (canola) has reshaped Asian rapeseed into two groups (double‐low and double‐high), accompanied by an increase in genetic load in the double‐low group. This study demonstrates distinctive genomic footprints and deleterious SNP (single nucleotide polymorphism) variants for local adaptation by recent intra‐ and interspecies introgression events and provides novel insights for understanding the rapid genome evolution of a young allopolyploid crop.     

Human T-cell leukemia virus type 1 infection leads to arrest in the G1 phase of the cell cycle

Infection by the human T-cell leukemia virus type 1 (HTLV-1) is thought to cause dysregulated T-cell proliferation, which in turn leads to adult T-cell leukemia/lymphoma. Early cellular changes after HTLV-1 infection have been difficult to study due to the poorly infectious nature of HTLV-1 and the need for cell-to-cell contact for HTLV-1 transmission. Using a series of reporter systems, we show that HeLa cells cease proliferation within one or two division cycles after infection by HTLV-1 or transduction of the HTLV-1 tax gene. HTLV-1-infected HeLa cells, like their tax-transduced counterparts, expressed high levels of p21^CIP1/WAF1 and p27^KIP1, developed mitotic abnormalities, and became arrested in G₁ in senescence. In contrast, cells of a human osteosarcoma lineage (HOS) continued to divide after HTLV-1 infection or Tax expression, albeit at a reduced growth rate and with mitotic aberrations. Unique to HOS cells is the dramatic reduction of p21^CIP1/WAF1 and p27^KIP1 expression, which is in part associated with the constitutive activation of the phosphatidylinositol-3-kinase (PI3K)-protein kinase B (Akt) pathway. The loss of p21^CIP1/WAF1 and p27^KIP1 in HOS cells apparently allows HTLV-1- and Tax-induced G₁ arrest to be bypassed. Finally, HTLV-1 infection and Tax expression also cause human SupT1 T cells to arrest in the G₁ phase of the cell cycle. These results suggest that productive HTLV-1 infection ordinarily leads to Tax-mediated G₁ arrest. However, T cells containing somatic mutations that inactivate p21^CIP1/WAF1 and p27^KIP1 may continue to proliferate after HTLV-1 infection and Tax expression. These infected cells can expand clonally, accumulate additional chromosomal abnormalities, and progress to cancer.