大乳头水螅基盘再生进程中过氧化物酶的表达

目的观察大乳头水螅(Hydra magnipapillata)基盘再生进程中基盘过氧化物酶的表达情况,探讨水螅基盘过氧化物酶的生理作用。方法通过ABTS细胞化学染色法显示水螅基盘过氧化物酶的表达。结果水螅基盘再生20h后其基盘过氧化物酶开始出现少量表达,其后过氧化物酶表达量逐渐增加;基盘再生52h后该酶表达量趋于稳定。过氧化物酶仅在基盘周边区域外胚层中表达,而在基盘中央区域(反口孔)外胚层中无表达。结论水螅基盘再生进程中过氧化物酶的表达量逐渐增加直接反映了基盘再生时细胞分化过程,基盘表达的过氧化物酶可能在维持基盘结构的稳定上起一定的作用。     

TGF-{beta}-induced MiR-491-5p expression promotes Par-3 degradation in rat proximal tubular epithelial cells

Par-3 is a component of Par complex, which is critical for the integrity of tight junction. We previously reported that TGF-β down-regulated Par-3 expression in rat proximal tubular epithelial cells, but the underlying mechanism remains unknown. In the present study, we demonstrated by a luciferase reporter assay that miR-491-5p down-regulated the luciferase activity through a binding site in the 3' UTR of Par-3. Overexpression of miR-491-5p dramatically decreased the expression of endogenous Par-3, disrupted tight junction, and resulted in decreased transepithelial resistance. Moreover, miR-491-5p expression was induced by TGF-β1 through the MEK/p38 MAPK pathway. Importantly, miR-491-5p levels were increased significantly in a rat model of obstructive nephropathy, in parallel with decreased Par-3 levels. Taken together, we conclude that up-regulation of miR-491-5p contributes to TGF-β-regulated Par-3 expression. Our study uncovered a novel mechanism by which TGF-β disrupts cell junction.     

Targeted In Vivo Extracellular Matrix Formation Promotes Neovascularization in a Rodent Model of Myocardial Infarction

Background

The extracellular matrix plays an important role in tissue regeneration. We investigated whether extracellular matrix protein fragments could be targeted with antibodies to ischemically injured myocardium to promote angiogenesis and myocardial repair.

Methodology/Principal Findings

Four peptides, 2 derived from fibronectin and 2 derived from Type IV Collagen, were assessed for in vitro and in vivo tendencies for angiogenesis. Three of the four peptides—Hep I, Hep III, RGD—were identified and shown to increase endothelial cell attachment, proliferation, migration and cell activation in vitro. By chemically conjugating these peptides to an anti-myosin heavy chain antibody, the peptides could be administered intravenously and specifically targeted to the site of the myocardial infarction. When administered into Sprague-Dawley rats that underwent ischemia-reperfusion myocardial infarction, these peptides produced statistically significantly higher levels of angiogenesis and arteriogenesis 6 weeks post treatment.

Conclusions/Significance

We demonstrated that antibody-targeted ECM-derived peptides alone can be used to sufficiently alter the extracellular matrix microenvironment to induce a dramatic angiogenic response in the myocardial infarct area. Our results indicate a potentially new non-invasive strategy for repairing damaged tissue, as well as a novel tool for investigating in vivo cell biology.     

人毛乳头细胞组织化学研究

毛乳头细胞是一种高度特殊化的成纤维细胞。本文通过对体外培养的毛乳头细胞进行组织化学染色研究发现,它对阿新蓝、甲苯胺蓝和PAS染色均呈阳性,并对甲苯胺蓝显异染性．与原位时的细胞染色结果相同,表明在体外培养下．毛乳头细胞合成和分泌酸性、中性粘多糖的能力仍能维持较长时间;在细胞聚集区和多层化细胞团中有丰富的细胞外基质,阿新蓝和PAS染色呈强阳性,说明细胞外基质的存在与毛乳头细胞的聚集有很大关系;另外毛囊真皮鞘细胞对阿新蓝、甲苯胺蓝染色呈阳性反应．无甲苯胺蓝的异染性,PAS染色阴性,而真皮成纤维细胞这些染色均阴性,说明它与毛乳头细胞关系密切。     

The effect of cell isolation methods on the human transcriptome profiling and microbial transcripts of peripheral blood

Molecular Biology Reports - The expression of human and microbial genes serves as biomarkers for disease and health. Blood RNA is an important biological resource for precision medicine and...     

Liver Retinol Transporter and Receptor for Serum Retinol-binding Protein (RBP4)

Vitamin A (retinol) is absorbed in the small intestine, stored in liver, and secreted into circulation bound to serum retinol-binding protein (RBP4). Circulating retinol may be taken up by extrahepatic tissues or recycled back to liver multiple times before it is finally metabolized or degraded. Liver exhibits high affinity binding sites for RBP4, but specific receptors have not been identified. The only known high affinity receptor for RBP4, Stra6, is not expressed in the liver. Here we report discovery of RBP4 receptor-2 (RBPR2), a novel retinol transporter expressed primarily in liver and intestine and induced in adipose tissue of obese mice. RBPR2 is structurally related to Stra6 and highly conserved in vertebrates, including humans. Expression of RBPR2 in cultured cells confers high affinity RBP4 binding and retinol transport, and RBPR2 knockdown reduces RBP4 binding/retinol transport. RBPR2 expression is suppressed by retinol and retinoic acid and correlates inversely with liver retinol stores in vivo. We conclude that RBPR2 is a novel retinol transporter that potentially regulates retinol homeostasis in liver and other tissues. In addition, expression of RBPR2 in liver and fat suggests a possible role in mediating established metabolic actions of RBP4 in those tissues.     

Simultaneous binding of two peptidyl ligands by a SRC homology 2 domain

Src homology 2 (SH2) domains mediate protein-protein interactions by recognizing phosphotyrosine (pY)-containing sequences of target proteins. In all of the SH2 domain-pY peptide interactions described to date, the SH2 domain binds to a single pY peptide. Here, determination of the cocrystal structure of the N-terminal SH2 domain of phosphatase SHP-2 bound to a class IV peptide (VIpYFVP) revealed a noncanonical 1:2 (protein-peptide) complex. The first peptide binds in a canonical manner with its pY side chain inserted in the usual binding pocket, while the second pairs up with the first to form two antiparallel β-strands that extend the central β-sheet of the SH2 domain. This unprecedented binding mode was confirmed in the solution phase by NMR experiments and shown to be adopted by pY peptides derived from cellular proteins. Site-directed mutagenesis and surface plasmon resonance studies revealed that the binding of the first peptide is pY-dependent, but phosphorylation is not required for the second peptide. Our findings suggest a potential new function for the SH2 domain as a molecular clamp to promote dimerization of signaling proteins.     

唐鱼养殖种群与广州附近4个野生种群的遗传关系

唐鱼(Tanichthys albonubes)是为数不多的几种原产中国的世界性观赏鱼类之一。自2003年以来, 多个唐鱼野生种群相继被发现, 其濒危状态和等级由野外灭绝降为极危。为研究唐鱼养殖种群与广州附近野生种群之间的遗传关系, 本文分析了唐鱼3个代表性养殖种群和4个野生种群, 共计186个样本的Cyt b基因、2个核基因(ENC1和RAG1)以及13个微卫星位点数据。基于K2P模型的遗传距离结果显示, 唐鱼野生种群间的遗传距离在0.005-0.015之间, 养殖种群间的遗传距离为0.001-0.009。系统发育分析表明, 唐鱼养殖种群包含4个单倍型谱系分支, 其中2个分别与广州附近2个野生种群聚在一起, 另外2个分别独立成支。单倍型网络亲缘关系分析显示, 清远种群只有1个单倍型且与芳村养殖种群共享, 芳村养殖种群拥有最多的单倍型。基于微卫星数据的STRUCTURE分析表明, 所有种群最佳分簇数为2, 清远种群与养殖种群聚为一簇, 良口和石门种群聚为另一簇。主成分分析结果显示, 养殖种群高度重叠并能与野生种群分开, 清远种群与养殖种群存在部分重叠。利用IMa3的基因流分析表明, 存在清远种群至芳村养殖种群的单向基因流。综合本文结果, 作者认为唐鱼养殖种群应起源于广州附近多个野生种群。清远种群来源于养殖种群中的芳村养殖种群。建议在未来唐鱼的保护策略中, 应禁止不规范的放流活动并且禁止将不同野生种群补充至养殖种群, 同时加强唐鱼养殖种群和野生种群的遗传资源管理和持续监测。