Up-regulation of ZO-1 expression and barrier function in cultured human corneal epithelial cells by substance P

The effects of the sensory neurotransmitter substance P on the expression of tight junction proteins and on barrier function in human corneal epithelial cells were investigated. The expression of ZO-1, but not that of occludin or claudin-1, was increased by substance P in a concentration- and time-dependent manner. This effect was inhibited by the NK-1 receptor antagonist GR82334 and by KN62, an inhibitor of Ca²⁺- and calmodulin-dependent protein kinase II. Substance P also increased the transepithelial electrical resistance of a cell monolayer in a manner sensitive to GR82334. Substance P may therefore play a role in maintenance of tight junctions in the corneal epithelium.     

Mannan-Binding Lectin: Structure, Oligomerization, and Flexibility Studied by Atomic Force Microscopy

Mannan-binding lectin (MBL) is the archetypical pathogen recognition molecule of the innate immune defense. Upon binding to microorganisms, reactions leading to the destruction of the offender ensue. MBL is an oligomer of structural subunits each composed of three identical polypeptides. We used atomic force microscopy to reveal tertiary and quaternary structures of MBL. The images in both air and buffer show a quaternary structure best described as “sertiform”, that is, a hub from which the subunits fan out. The dimensions conform to those calculated from primary and secondary structures. The subunits associate with a preferred angle of 40° between them. This angle is stable with respect to the degree of oligomerization for MBL of four subunits or more. Due to an interruption in the collagenous sequence, the arms of the subunits are expected to form a kink. We find that ∼ 30% of the subunits are kinked and the kink angle distributed, quite broadly, around 145°. The conformation and flexibility of the MBL molecule that we observe differ distinctly from the popular view of a “bouquet-like” configuration as that found for related members of the complement system such as C1q. This structural information will further the understanding of the specific functioning of the MBL pathway of complement activation.     

昆虫雄性生殖腺分泌物的功能

昆虫两性成功交配后,雄性生殖腺分泌物使雌性昆虫的生理和行为都发生了巨大的改变。昆虫雄性生殖腺分泌物含有多种具有生物活性的分子,这些生物活性分子通过成功交配转移到雌虫生殖道后,对雌虫的生殖活动产生影响,使交配雌虫一段时间内不再交配,使已转移的精子易于在雌虫生殖道内储藏,使卵与精子完成受精过程,还可刺激雌虫产卵和卵的发育,调控排卵和产卵等生殖过程。在精子的转移过程中,雄性生殖腺分泌物中的抗菌媒介质能使雌虫的生殖导管提供友好的环境。此外,一些昆虫的雄性生殖腺分泌物还含有一些有毒的化学物质,保护已产下的卵不被天敌取食和病原体侵染。     

Recent advances in quantitative colocalization analysis: Focus on neuroscience

Quantitative colocalization analysis is an advanced digital imaging tool to characterize the spatial expression of molecules of interest in immunofluorescence images obtained using confocal microscopes. It began from simple pixel counting and, with introduction of specialized algorithms, transformed into a powerful image analyzing technique capable of identifying the exact locations of various molecules in tissues and cells and describing their subtle changes in dynamics. Applications of quantitative colocalization in the field of neuroscience proved to be particularly informative by helping to obtain observations not otherwise achievable using other techniques. In this article, we review the background and applicability of quantitative colocalization with special focus on neuroscience research.     

Exposure to the seminal plasma of different portions of the boar ejaculate modulates the survival of spermatozoa cryopreserved in MiniFlatPacks

Spermatozoa present in the first collectable 10 mL of the sperm-rich fraction (SRF) of the boar ejaculate (portion 1, P1) have higher documented viability during and after cryopreservation than spermatozoa in the rest of the ejaculate (portion 2, P2), probably in relation to different features of the surrounding seminal plasma (SP). In the present study, we investigated whether the SP from these ejaculate portions (SP1 or SP2) was able to differently influence sperm viability and chromatin structure of the P1- or P2-contained spermatozoa from individual boars primarily or secondarily exposed (e.g., following cleansing and re-exposure) to pooled SP1 or SP2 from the same males during 60 min. Spermatozoa were subjected to controlled cooling and thawing in MiniFlatPacks (MFPs) and examined for motility (using computer-assisted sperm analysis, CASA) at selected stages of processing. Moreover, sperm plasma membrane intactness (investigated using SYBR-14/propidium iodide, PI), plasma membrane architecture (examined using Annexin-V-PI staining), and chromatin (deoxyribonucleic acid, DNA) integrity (tested using sperm chromatin structure assay, SCSA) were assessed post-thaw (PT). A higher proportion of P1 spermatozoa than of P2 spermatozoa incubated in their native SP portion were confirmed to be motile from collection to PT. When P1 spermatozoa were cleansed from their original SP and re-exposed to pooled P2-SP, sperm kinematics deteriorated from extension to PT. By contrast, cleansed P2 spermatozoa increased motility to P1 levels, especially PT when re-exposed to pooled P1-SP. Such differential effects on motility were not clearly accompanied by biologically related modifications of sperm membrane or chromatin structure. This influence of the SP on sperm kinematics was not sire-dependent and it was presumably related to different concentrations or either SP proteins or bicarbonate in the different ejaculate portions.     

P物质受体在大鼠纹状体边缘区内的表达

我们以前的工作观察到纹状体边缘区内有密集的P物质纤维及终末分布,本用原位杂交和免疫组织化学方法研究了大鼠纹状体边缘区内P物质受体（SPR）的表达及分布,原位杂交结果发现P物质mRNA阳性杂交信号在纹状体内的分布不均匀,尾壳核内只有少量中等大小的阳性胞体,苍白球内只有少量较大的阳性胸体,而在尾壳核和苍白球之间的边缘区部位则可见许多中等大小的梭形阳性神经元胞体,并呈现密集的带关分布。免疫组织化学结果观察到P物质阳性神经元胞体在纹状体内的分布与原位杂交结果一致。推测大鼠纹体边缘区内可以合成P物质受体,具有接受和整合P物质神经递质的功能,推测边缘区内SPR神经元可能对SP递质的接受、调节有重要作用。     

Lysine acetylation stabilizes SP2 protein in the silkworm Bombyx mori

Lysine acetylation (Kac) is a vital post-translational modification that plays an important role in many cellular processes in organisms. In the present study, the nutrient storage proteins in hemolymph were first found to be highly acetylated—particularly SP2 protein, which contains 20 potential Kac sites. Further results confirmed that lysine acetylation could stabilize and up-regulate the protein level of anti-apoptosis protein SP2, thereby improving the survival of H₂O₂-treated BmN cells and suppressing the apoptosis induced by H₂O₂. The potential mechanism involved in the inhibition of ubiquitin-mediated proteasomal degradation by crosstalk between lysine acetylation and ubiquitination. Our results showed that the increase in the acetylation level by TSA could decrease the ubiquitination and improve the protein level of SP2, indicating that lysine acetylation could influence the SP2 protein level through competition between ubiquitination and the suppression of ubiquitin-mediated proteasomal degradation, thereby stabilizing the protein. SP2 is a major nutrient storage protein from hemolymph for amino acid storage and utilization. The crosstalk between lysine acetylation and ubiquitination of SP2 might imply an important role of lysine acetylation for nutrient storage and utilization in silkworm.     

神经肽CGRP、SP、NPY对软骨细胞的影响研究

近年来,由于创伤和感染等多类原因导致的骨折和骨不连等症状均是威胁到人类生命安全及生活质量的一个医学难题,为了更好地提升对于此类患者的治疗效果,有必要明确骨形成和重建等病理生理学情况以及相应的生物学机制。同时,骨组织是一类随细胞外基质的矿化,并根据其自身需求进行修复的动态组织,也是有着血管和神经支配的活性组织,所以,骨折的修复过程当中不仅含机体各类组织和细胞因子间的复杂作用,还和血液供应及神经支配紧密相连。目前,临床关于神经肽的研究逐渐增多,且越来越多的报道表明神经肽类物质能够在骨折愈合及重建过程中发挥出重要作用,原因可能和机体神经发挥相应的调控作用,并刺激骨细胞发生变化等因素有关。本文即据此展开关于神经肽CGRP(降钙素基因相关肽,Calcitonin gene-related peptide)、SP(P物质,Substance P)、NPY(神经肽Y,Neuropeptide Y)对软骨细胞影响情况的综述分析,从而更好地服务临床。     

Response surface optimization of prodigiosin production by phthalate degrading Achromobacter denitrificans SP1 and exploring its antibacterial activity

Abstract

The role of various parameters like temperature, pH, blood bag concentration, agitation and incubation that influence the production of prodigiosin by Achromobacter denitrificans SP1 was determined. The Plackett–Burman and Box–Behnken experimental designs were employed to statistically optimize and find out the best combinational effect of parameters for the better yield of prodigiosin using blood bag as sole carbon and energy source for the growth of A. denitrificans SP1. The maximum (1.314?mg/ml) prodigiosin production was attained at a temperature of 24?°C, pH (8.8), and blood bag (1?g) as optimum; while the predicted value was 1.319?mg/ml with a correlation coefficient of 0.987; which signifies the fitness of the model. Antimicrobial activity of the prodigiosin was also evaluated and found to be an effective agent against bacterial pathogens including Staphylococcus aureus and Proteus mirabilis. Utilization of the plasticizer di (2-ethylhexyl)phthalate (DEHP) in blood bag and the production of antibacterial prodigiosin makes A. denitrificans SP1, an effective competitor toward the pathogenic bacterial disinfection and wastewater treatment processes.