小鼠胚胎神经干细胞培养方法的改良、优化及鉴定

目的通过培养神经球来培养神经干细胞的方法是最常用的扩增神经干细胞方法。但是该方法的缺陷是神经干细胞在冻存和复苏的过程中死亡率高,不能达到高效地扩增神经干细胞的目的。本文章的实验目的是建立不通过培养神经球而直接扩增神经干细胞的方法。方法通过从小鼠大脑胚层组织中获取神经干细胞、如何传代以及冻存的步骤进行了优化比较并对复苏后的神经干细胞进行干性鉴定。结果通过比较使用胰蛋白酶、胰蛋白酶和核酸酶、木瓜酶在消化小鼠大脑皮层组织并获得神经干细胞的效率,发现使用胰蛋白酶获得的神经干细胞的数量最多,在质量上和其它两种方法没有明显的差异。在传代过程中,通过比较使用化学消化液和胰蛋白酶消化液,发现胰蛋白酶消化后的神经干细胞存活率比化学消化液高。结论使用收集的神经干细胞培养液和10%DMSO作为冻存液,神经干细胞的复苏存活率达到90%以上。复苏后的神经干细胞在传代两次后仍然高表达干性基因Sox2、Nestin和Pax6。     

An ultrastructural study on the ear cartilage of rabbits after the administration of papain

Summary Crude papain was administered intravenously to young rabbits and the cartilage of the collapsed ear was examined electron-microscopically. Degeneration and recovery of chondrocytes, and decrease in and recovery of the electron-density of elastic fibers, were observed during the collapse and restoration of the ear. Some samples were stained with ruthenium red. In the collapsed ear, with a marked decrease of proteoglycan in the cartilage, loss of ruthenium red-positive granules was observed in the extracellular matrix. Collagen fibrils in the cartilage appeared to be somewhat increased in number, some of their diameters became slightly greater, and a part were assembled into bundles, occasionally accompanied by periodic crossstriation. Decrease of proteoglycan in the cartilage matrix probably brought about the unmasking and the assembly of collagen fibrils. In one of the experimental animals, collagen fibrous segments of an atypical fibrous long spacing (FLS-)type with symmetrical cross-striation were found around the chondrocytes in the ear cartilage, during the period of recovery. Some kind of the endogenous sulfated carbohydrate may have acted to affect the arrangement of type II collagen or procollagen molecules newly produced by the recovering chondrocytes.     

Low-molecular-weight proteinase inhibitor of human epidermis inhibiting papain and trypsin activity

Summary A low-molecular-weight proteinase inhibitor was isolated from human epidermal extracts by means of ultrafiltration, gel filtration and ion-exchange chromatography. On polyacrylamide gel electrophoresis (PAGE), the isolated fraction exhibited a single band of activity at pH 9.4, and inhibitory activity against papain and trypsin was detected in this band. Using sodium-dodecyl-sulphate PAGE, the molecular mass of the inhibitor was estimated to be 2,200 daltons.     

Comparison of two different benzodiazepine binding proteins by peptide mapping after limited proteolysis

Proteins P₅₁ and P₅₅ were photolabeled by [³H]flunitrazepam, [³H]clonazepam or ³H-Ro 15–4513 and then compared by peptide mapping after limited digestion with various proteases. Results indicated that [³H]flunitrazepam or [³H]clonazepam irreversibly bind to the same and [³H]Ro 15–4513 to a different part of these proteins. The different radiolabeled peptide patterns obtained from P₅₁ or P₅₅ irrespective of the photolabel used, suggest a difference in the molecular structure of these proteins.     

云南峨山番木瓜中木瓜蛋白酶的初步纯化及活性测定

应用FPLC系统对采自云南峨山县的番木瓜乳汁中的木瓜蛋白酶进行了初步纯化,同时,用基梅尔-史密斯法测定了番木瓜乳汁中木瓜蛋白酶的活性。结果表明:不同瓜形之间的木瓜蛋白酶活性大小没有明显差异,但与瓜的成熟度有关。     

IL‐1R1–MyD88 axis elicits papain‐induced lung inflammation

Allergic asthma is characterized by a strong Th2 response with inflammatory cell recruitment and structural changes in the lung. Papain is a protease allergen disrupting the airway epithelium triggering a rapid inflammation with eosinophilia mediated by innate lymphoid cell activation (ILC2) and leading to a Th2 immune response. In this study, we focused on inflammatory responses to a single exposure to papain and showed that intranasal administration of papain results in the recruitment of inflammatory cells, including neutrophils and eosinophils with a rapid production of IL‐1α, IL‐1β, and IL‐33. The inflammatory response is abrogated in the absence of IL‐1R1 and MyD88. To decipher the cell type(s) involved in MyD88‐dependent IL‐1R1/MyD88 signaling, we used new cell‐specific MyD88‐deficient mice and found that the deletion of MyD88 signaling in single cell types such as T cells, epithelial cells, CD11c‐positive or myeloid cells leads to only a partial inhibition compared to complete absence of MyD88, suggesting that several cell types contribute to the response. Importantly, the inflammatory response is largely ST2 and IL‐36R independent. In conclusion, IL‐1R1 signaling via MyD88 is critical for the first step of inflammatory response to papain.     

骨髓间充质干细胞移植对木瓜蛋白酶和［60Co］照射所致大鼠肺气肿的作用

目的：研究骨髓间充质干细胞（MSCs）移植对木瓜蛋白酶和［⁶⁰Co］照射所致肺气肿的影响及其机制。方法：雌性大鼠随机分为对照组、肺气肿组和肺气肿+MSCs移植组。将大鼠进行［⁶⁰Co］照射，在气管内滴入木瓜蛋白酶建立雌性大鼠肺气肿模型，然后将培养的雄性大鼠MSCs经尾静脉注射到雌性肺气肿大鼠。观察移植后大鼠肺组织的病理学变化；通过PCR和Y染色体荧光原位杂交（Y-FISH）示踪雄性大鼠MSCs在雌性肺气肿大鼠肺组织内的植入情况；用Y-FISH和肺泡表面活性物质蛋白C（SP-C）免疫荧光显色方法检测雄性大鼠MSCs在受体肺组织内是否分化为II型肺泡上皮细胞。结果：肺气肿组、肺气肿+MSCs移植组大鼠均出现肺气肿改变，但后者较前者的肺气肿明显减轻，2组之间的肺泡平均内衬间隔、平均肺泡面积和单位面积肺泡数均有显著差异；PCR结果显示肺气肿+MSCs移植组的大鼠肺脏基因组DNA中可以扩增出位于Y染色体的Sry基因片段；Y-FISH显示肺气肿+MSCs移植组的雌性大鼠肺组织中有Y染色体阳性的细胞，并且部分Y染色体阳性细胞同时表达SP-C。结论：MSCs移植能够减轻木瓜蛋白酶和［⁶⁰Co］照射所致的肺气肿，这可能与移植的MSCs在受体肺组织中的植入和分化为II型肺泡上皮细胞有关。     

The effect of proteolytic enzymes on hair follicles of transgenic mice expressing the lac Z-protein in cells of the bulge region

OBJECTIVE: To study the effects of proteolytic enzymes on mice hair follicles, particularly on cells of the bulge area regarded as follicle stem cells. BACKGROUND: Previous application by iontophoresis of proteolytic enzymes on guinea pig skin resulted in degenerative effects on hair follicles and the hypothesis was proposed that some of the affected cells could be stem cells. METHODS: To mark putative stem cells transgenic mice were produced carrying the lac-Z gene fused to the Upstream Regulatory Region (URR) of Human Papilloma Virus 11 (HPV11), as they express this gene specifically in the cells of the bulge area. Chymotrypsin and papain were applied on skin by iontophoresis, trypsin in the form of liposomes. RESULTS: Enzyme application, both by electrophoresis and as liposomes, led to intense degenerative effects of the hair follicle, such as detachment of the inner root sheath, cystic dilation of the hair shaft and presence of epithelial cells within the lumen. Some of these cells represent hair follicle stem cells expressing beta-galactosidase (beta-gal), having been detached from the bulge area as a result of enzyme treatment, implying impairment of their function.