IgA肾病患者与健康人肠道菌群的比较

目的通过16S rRNA高通量基因测序方法对IgA肾病患者与健康人的肠道菌群进行比较。方法纳入生活于同一地区的40例IgA肾病患者与10例健康人,收集研究对象的新鲜粪便样本,提取粪便细菌总DNA,通过PCR扩增后上机测序,然后进行可操作分类单元聚类、物种分类分析及Alpha多样性分析、Beta多样性分析,最后比较两组之间的肠道菌群差异。结果与健康人相比,IgA肾病患者肠道菌群丰富度指数(Ace、Chao1)下降(u=2.308,P=0.033;u=2.259,P=0.039),多样性指数(Shannon、Simpson)升高(u=5.370,P0.001;u=4.601,P=0.007);相对丰度方面,IgA肾病患者的厚壁菌门、拟杆菌门、放线菌门细菌数量增加(t=2.301,P=0.037;t=6.729,P=0.005;t=5.285,P=0.006),而变形菌门细菌数量减少(t=4.138,P=0.009);拟杆菌属、链球菌属细菌数量增加(t=9.037,P=0.003;t=6.001,P=0.008),而unidentified_Enterobacteriaceae数量减少(t=2.198,P=0.033)。PCoA图提示两组肠道菌群有显著差异。LDA差异贡献分析发现两组之间共有15个物种存在显著差异,其中造成显著差异影响力最大的5个物种依次是γ-变形菌纲、unidentified_Enterobacteriaceae、肠杆菌科、肠杆菌目、变形菌门(t=9.930,P=0.002;t=2.198,P=0.033;t=2.604,P=0.015;t=2.393,P=0.021;t=4.138,P=0.009),它们刚好落在同一个进化树上,在IgA肾病组的相对丰度显著降低。结论 IgA肾病患者存在肠道菌群失调,显著减少的肠杆菌科的未知属可能是IgA肾病的特征菌,其对机体免疫的影响及在IgA肾病发生发展中的作用尚不清楚,进一步研究可能为IgA肾病的防治提供新的靶点。     

Chinese plasma-derived products supply under the lot release management system in 2007–2011

In 2007, the Chinese State Food and Drug Administration (SFDA) implemented a management system for lot release of all plasma-derived products. Since then, there have been only a few systematic studies of the blood supply, which is a concern when considering the small amount of plasma collected per capita (approximately 3 L/1000 people). As a result, there may be a threat to the safety of the available blood supply. In this study, we examined the characteristics of the supply of Chinese plasma-derived products. We investigated the reports of lot-released biological products derived from all 8 national or regional regulatory authorities in China from 2007 to 2011. The market supply characteristics of Chinese plasma-derived products were analyzed by reviewing the changes in supply varieties, the batches of lot-released plasma-derived products and the actual supply. As a result, the national regulatory authorities can more accurately develop a specific understanding of the production and quality management information provided by Chinese plasma product manufacturers. The implementation of the lot release system further ensures the clinical validity of the plasma-derived products in China and improves the safety of using plasma-derived products. This work provides an assessment of the future Chinese market supply of plasma-derived products and can function as a theoretical basis for the establishment of hemovigilance.     

Single-chain antibody fragments: Purification methodologies

At present, single-chain variable fragments (scFv) of antibodies are considered one of the most important tools in human therapies. Wide applications of antibodies are being exploited in different medical, pharmaceutical and research areas. These molecules maintain the same binding functionality that full length antibodies but possess several advantageous features as quickness to penetrate the tissues, easy manipulation, fast elimination of their immunocomplex and the possibility of being produced in simple expression systems like bacteria and yeast. The increasing demand in antibody based methodologies is driving advances in the production and purification of genetically engineered antibodies and antibody fragments. While advances in expression systems allow the production of high titers of antibodies, there exist some limits imposed by the downstream methodologies which are not efficient enough to ensure their industrialization.The main aim of this review is to highlight the principal characteristics of single-chain variable fragments of antibodies addressing advances and perspectives on scFv purification.     

The N-end rule proteolytic system in autophagy

The N-end rule pathway is a cellular proteolytic system that utilizes specific N-terminal residues as degradation determinants, called N-degrons. N-degrons are recognized and bound by specific recognition components (N-recognins) that mediate polyubiquitination of low-abundance regulators and selective proteolysis through the proteasome. Our earlier work identified UBR4/p600 as one of the N-recognins that promotes N-degron-dependent proteasomal degradation. In this study, we show that UBR4 is associated with cellular cargoes destined to autophagic vacuoles and is degraded by the lysosome. UBR4 loss causes multiple misregulations in autophagic pathways, including an increased formation of LC3 puncta. UBR4-deficient mice die during embryogenesis primarily due to defective vascular development in the yolk sac (YS), wherein UBR4 is associated with a bulk lysosomal degradation system that absorbs maternal proteins from the YS cavity and digests them into amino acids. Our results suggest that UBR4 plays a role not only in selective proteolysis of short-lived regulators through the proteasome, but also bulk degradation through the lysosome. Here, we discuss a possible mechanism of UBR4 as a regulatory component in the delivery of cargoes destined to interact with the autophagic core machinery.     

Immunoglobulin immobilized liposomal constructs for transmucosal vaccination through nasal route

The aim of the present investigation was to evaluate the prospective of surface-engineered vesicular carriers for mucosal immunization via the nasal route. IgG antibody was immobilized on the surface of hepatitis B surface antigen (HBsAg) antigen–loaded liposomes. The developed formulations were characterized on the basis of physicochemical parameters, such as morphology, particle size, polydispersity index, entrapment efficiency, and zeta potential. Liposomal formulations were then evaluated for in-process antigen stability and storage stability. In vivo studies were conducted to visualize targeting potential, localization pattern, and immunogenicity. In addition, immune response was compared with alum-HBsAg vaccine injected intramuscularly. The serum anti-HBsAg titer, obtained from the postnasal administration of IgG-coupled liposomes, was significantly higher than plain liposomes. Moreover, IgG-coupled liposomes generated both humoral (i.e., systemic and mucosal) and cellular immune responses upon nasal administration, while the alum-adsorbed antigen displayed neither cellular (cytokine level) nor mucosal (IgA) response. The formulation also displayed enhanced transmucosal transport, improved in vitro stability, and effective immunoadjuvant property. To conclude, IgG antibody-coupled liposomes may serve as novel carriers to augment the secretory immune response of antigen encapsulated in the liposomes, apparently by escalating liposome uptake via M cells, thereby rationalizing their use as a carrier adjuvant for nasal subunit vaccines.     

Lecithotrophic development and metamorphosis in the Indo-West Pacific brittle star Ophiomastix venosa (Echinodermata: Ophiuroidea)

Summary

The larval development of the ophiocomid ophiuroid Ophiomastix venosais described using SEM. The gastrula transforms into a uniformly ciliated early larva which progressively changes into a lecithotrophic late premetamorphic larva with a continuous bilateral ciliated band. This stage is short-lived and equivalent to a highly reduced ophiopluteus. Comparisons between O. venosa and other ophiuroid species whose development has been investigated suggest that, whatever the developmental mode (lecithotrophic or planktotrophic), a pluteus stage always occurs in ophiuroids with planktonic development. Two metamorphic stages were identified, the late metamorphic larva differing from the early one by the closure of the larval mouth. The appearance of the permanent mouth marks the end of the metamorphosis. The postlarva still possesses remnants of larval features. The transformation of the reduced ophiopluteus into a barrel-shaped metamorphic larva with transverse ciliated bands, a vitellaria larva, is followed. The possible occurrence of a unique type of metamorphic larva in non-brooding ophiuroids is discussed. Verification of this, however, needs further SEM investigations on metamorphic larva from species having “regular” planktotrophic development.     

Bombyx acid cysteine proteinase

Summary

Three kinds of yolk proteins (vitellin, egg-specific protein and 30 k-proteins) are found in silkmoth eggs and have been well characterized. Essentially these proteins are considered to be amino acid reserves for developing embryos. Since at an early stage of egg development the cysteine proteinase accounts for the majority of the total proteinase activity, it may be involved in the degradation of yolk proteins. The enzyme is stored in the eggs as an inactive pro-form, indicating that the activation of the enzyme might be one of the key steps in yolk protein degradation. To investigate at the molecular level how yolk proteins degradation takes place, we have studied Bombyx acid cysteine proteinase (BCP) during an early period of embryonic development. We summarize how proteinases are regulated and are involved in the degradation of Bombyx yolk proteins during embryogenesis. These will be discussed mainly in light of recent results obtained from eggs of the silkmoth, Bombyx mori.     

Trans-order yolk protein can stimulate endocytic activity in Drosophila oocytes

Vitellogenins (Vgs) and mature yolk from some non-Dipteran insects can be recognized by Drosophila melanogaster oocyte Vg receptors and incorporated via receptor-mediated endocytosis into nascent yolk spheres (NYS). It had previously been assumed that only Vgs of Drosophila or other Dipterans could be so endocytosed. Drosophila ovarian follicles from 4-day old females were incubated in the presence of physiological salt solution (PSS) containing some fluorescent TexasRed-Dextran (Dex-red) or PSS-Dex-red in which either female hemolymph, or vitellin (mature yolk) from lysed oocytes was present from any of the following: (1) Drosophila (Diptera); (2) Oncopeltus (milkweed bug, Hemiptera); (3) Acteaus (luna moth, Saturniidae Lepidoptera); (4) Papilio (swallowtail butterfly, Papilionidae Lepidoptera); or (5) Xylocopa (carpenter bee, Hymenoptera). Under incubation conditions, any NYS would become fluorescent due to non-specific fluid-phase uptake. Ovarian follicles incubated in PSS-DexRed alone or in PSS with hemolymph from males did not carry out endocytosis detectable by this technique, but all other treatments listed above did.     

The ecdysoid RH5849 induces yolk polypeptide synthesis in male flies

Summary

RH5849 is a benzoyl hydrazine analog which has been reported to mimic several effects of the arthropod steroid hormone ecdysone to which it is chemically totally unrelated. In adult Diptera, ecdysone is the hormone that triggers vitellogenin synthesis. We report here that RH5849, upon oral ingestion, is able to induce vitellogenin synthesis in male Drosophila, Neobellieria, Phormia and Lucilia. This contrasts to data in the literature which showed that RH5849 could not mimic the pupariation-inducing effect of ecdysone in last instar fly larvae. RH5849 neither exerts a juvenile hormone mimicking effect nor behaves as an anti-juvenile hormone in both the Colorado potato beetle and Galleria.