Chronic sleep loss disrupts blood–testis and blood–epididymis barriers,and reduces male fertility

Sleep loss increases blood–brain barrier permeability. As the blood–brain barrier and the blood–tissue barriers in the reproductive tract (blood–testis and blood–epididymis barriers) share common characteristics, we hypothesized that sleep restriction may also modify their barrier function. Previous reports showed that sleep loss decreased sperm viability and progressive fast mobility, which may be a consequence of altered blood–testis and blood–epididymis barrier. Therefore, we quantified changes in blood–testis and blood–epididymis barrier after sleep loss and related them to male fertility. Adult male Wistar rats were sleep restricted using the multiple‐platform technique in a protocol of 20 hr daily sleep deprivation plus 4 hr of sleep recovery in the home‐cage. At the 10th day, barrier permeability assays were performed with Na‐fluorescein, 10 kDa Cascade blue‐dextrans and Evans blue, and the expression of tight junction proteins, actin and androgen receptor was quantified. At the 10th day of sleep restriction and after sleep recovery days 1–7, males were placed with sexually receptive females, sexual behaviour was tested, and the percentage of pregnancies was calculated. Sleep restriction increased the barrier permeability to low‐ and high‐molecular‐weight tracers, and decreased the expression of tight junction proteins, actin and androgen receptor. Concomitantly, sleep restriction reduced the percentage of ejaculating males and the number of pregnancies. Sleep recovery for 2–3 days progressively re‐established fertility, as indicated by a higher percentage of ejaculating males and impregnated females. In conclusion, chronic sleep loss alters fertility concomitantly with the disruption of the blood–tissue barriers at the reproductive tract, the mechanism involves androgen signalling.     

Comprehensive molecular screening strategy of OCLN in band‐like calcification with simplified gyration and polymicrogyria

Occludin (OCLN) is an important component of the tight junction complex, providing apical intercellular connections between adjacent cells in endothelial and epithelial tissue. In 2010 O'Driscoll et al reported mutations in OCLN to cause band‐like calcification with simplified gyration and polymicrogyria (BLC‐PMG). BLC‐PMG is a rare autosomal recessive syndrome, characterized by early onset seizures, progressive microcephaly, severe developmental delay and deep cortical gray matter and basal ganglia calcification with symmetrical, predominantly fronto‐parietal, polymicrogyria. Here we report 4 additional cases of BLC‐PMG with novel OCLN mutations, and provide a summary of the published mutational spectrum. More generally, we describe a comprehensive molecular screening strategy taking into account the technical challenges associated with the genetic architecture of OCLN, which include the presence of a pseudo‐gene and copy number variants.     

低氧对原代支持细胞增殖能力和occludin蛋白表达的影响

目的:观察低氧对原代大鼠睾丸支持细胞生长活性、occludin蛋白表达的影响。方法:18～22日龄Wistar大鼠,通过两步酶消化法,建立原代支持细胞培养体系,经油红O、免疫荧光法鉴定。传代后随机分为以下氧浓度组进行培养:20%、15%、10%、5%和1%。分别培养至6、12、24、48、72 h,CCK-8测定细胞增殖活性,West-ern印迹测定occludin蛋白表达量,并进行差异性分析。结果:油红O染色见胞质内脂滴染成红色,免疫荧光见FasL蛋白表达阳性,细胞纯度>95%。与20%氧浓度相比,细胞在15%和10%氧浓度下增殖率逐渐降低,5%和1%氧浓度下,细胞增殖率明显下降(P<0.01);从12 h开始,随着氧浓度降低和时间延长,occludin表达量明显下降(P<0.01)。结论:低氧会抑制支持细胞生长,并减少occludin蛋白表达。推测低氧环境损伤支持细胞参与的血睾屏障完整性,影响睾丸的生精过程。     

Effects of Lipopolysaccharide on the Blood-Brain Barrier Permeability in Prolonged Nitric Oxide Blockade-Induced Hypertensive Rats

The authors investigated the effects of lipopolysaccharide (LPS) on the blood-brain barrier (BBB) integrity and the activity of astrocytes during the N^w-nitro-L-arginine methyl ester (L-NAME) hypertension followed by angiotensin (ANG) II in rats. They measured the changes in the BBB permeability using the Evans blue (EB) dye and concomitantly in the levels of TNF-a, IL-1b, and IL-6 in serum and nitric oxide in plasma. The authors performed two tight junction-specific proteins, zonula occludens-1 and occludin, and glial fibrillary acidic protein, by using immunohisto-chemical method. The serum levels of TNF-α, IL-1β, IL-6, and the plasma level of nitric oxide significantly increased in LPS-treated rats (p < .01). The EB dye extravasation increased in cerebellum (p < .001) and diencephalon (p < .05) of L-NAME plus ANG II-treated animals. However, LPS reduced the increased EB dye extravasation in the brain regions of L-NAME-induced hypertensive rats treated with ANG II (p < .001). In L-NAME, there was a considerable loss of staining in both zonula occludens-1 and occludin. Staining for zonula occludens-1 and occludin was highly intensive in animals treated with LPS. Glial fibrillary acidic protein staining was seen in a few astrocytes in brains of L-NAME-treated animals. However, this staining showed an increased intensity in the brain sections of animals treated with LPS. This study indicates that, in L-NAME hypertensive rats, ANG II leads to an increase in the extravasation of EB dye to brain as a result of decreased activity of tight junction proteins and astrocytes, and LPS could significantly attenuate the EB dye transport to the brain through the increased activity of tight junction proteins and astrocytes.     

Lysophosphatidic acid regulates adhesion molecules and enhances migration of human oral keratinocytes

Oral keratinocytes are connected via cell‐to‐cell adhesions to protect underlying tissues from physical and bacterial damage. Lysophosphatidic acids (LPAs) are a family of phospholipid mediators that have the ability to regulate gene expression, cytoskeletal rearrangement, and cytokine/chemokine secretion, which mediate proliferation, migration, and differentiation. Several forms of LPA are found in saliva and gingival crevicular fluid, but it is unknown how they affect human oral keratinocytes (HOK). The aim of the present study was therefore to examine how different LPA forms affect the expression of adhesion molecules and the migration and proliferation of HOK. Keratinocytes were isolated from gingival biopsies obtained from healthy donors and challenged with different forms of LPA. Quantitative real‐time RT‐PCR, immunocytochemistry, and flow cytometry were used to analyze the expression of adhesion molecules. Migration and proliferation assays were performed. Lysophosphatidic acids strongly promoted expression of E‐cadherin and occludin mRNAs and translocation of E‐cadherin protein from the cytoplasm to the membrane. Occludin and claudin‐1 proteins were up‐regulated by LPA. Migration of HOK in culture was increased, but proliferation was reduced, by the addition of LPA. This indicates that LPA can have a role in the regulation of the oral epithelial barrier by increasing the expression of adhesion molecules of HOK, by promotion of migration and by inhibition of proliferation.     

重症急性胰腺炎大鼠肝脏毛细血管渗漏的发生机理

目的探讨重症急性胰腺炎(SAP)大鼠肝脏毛细血管渗漏的发生机理。方法 40只SD大鼠采用完全随机法随机分为假手术(sham operation,SO)组和SAP组,SAP按不同的取材时间又分为3、6、12及24 h 4个亚组,每组8只。以胰胆管逆行注射5%牛磺胆酸钠建立SAP模型,观察各组肝脏组织病理改变,检测血清肿瘤坏死因子(TNF)-α水平,干湿重法检测肝脏组织含水率,免疫组织化学方法检测肝脏组织中occludin蛋白表达水平,RT-PCR法检测肝脏组织中occludin mRNA表达水平。结果 SO组肝脏组织病理无明显改变;SAP组肝脏组织表现为典型SAP病理改变,包括血管扩张明显、组织疏松水肿、炎性细胞浸润。SAP组各时相TNF-α水平、肝脏组织含水率逐渐升高,在观察时间范围内,24 h时均达最高,TNF-α水平、肝脏组织含水率在SAP组不同时相比较差异均有统计学意义(P<0.05),且SAP组不同时相均明显高于SO组(P<0.05)。SAP组3 h时occludin蛋白和mRNA水平均开始降低,6 h时达最低值,12 h和24 h时较6 h时明显升高(P<0.05),但仍均低于SO组(P<0.05)。结论 SAP大鼠肝脏发生严重的毛细血管渗漏,可能与SAP时TNF-α表达上调,导致紧密连接蛋白occludin及其mRNA表达下调有关。     

NO体外对肠上皮细胞表达紧密连接蛋白Occludin的影响

目的:探讨一氧化氮(NO)对肠上皮细胞表达紧密连接蛋白Occludin的影响,以研究NO对肠黏膜屏障的作用机制.方法:将NO的供体Sin1与肠上皮细胞株Caco-2共培养24 h,采用MTT方法观察NO对肠上皮细胞的作用,并分别提取细胞蛋白和总RNA,采用免疫蛋白印迹(Westem blot)蛋白半定量方法和实时定量聚合酶链式反应(RO-PCR)方法检测不同NO浓度对Caco-2细胞表达紧密连接蛋白Occludin蛋白和mRNA表达的影响.结果:随着Sin1浓度升高(125,250,500和1000μmol/L)NO对细胞的杀伤作用产生并逐渐增大,Occludin蛋白表达量和mRNA的相对表达量与无Sin1刺激时蛋白及mRNA的表达量相比明显降低(蛋白:375±0.5,374±0.8,363±0.3.363±0.7 vs 398±0.7;mRNA:0.689±0.01,0.578±0.09,0.554±0.03,0.619±0.04 vs 1,均P<0.01).结论:NO可直接损伤肠上皮细胞,同时以剂量依赖形式在蛋白和分子水平影响紧密连接蛋白Occludin的表达.     

miR-19a对血肿瘤屏障通透性的影响

目的研究miR-19a对血肿瘤屏障通透性的影响。方法将miR-19a模拟物转染至人脑微血管内皮细胞hCMEC/D3,应用real-timePCR法检测miR-19a的表达。用过表达miR-19a的hCMEC/D3细胞和人U251胶质瘤细胞建立体外血肿瘤屏障模型,跨内皮电阻测量系统检测血肿瘤屏障跨内皮阻抗值的变化;Western blot和免疫荧光法检测体外血肿瘤屏障hCMEC/D3细胞中,紧密连接相关蛋白ZO-1和occludin的表达。结果经miR-19a模拟物转染后,hCMEC/D3细胞中miR-19a的表达水平显著升高;血肿瘤屏障跨内皮阻抗值显著下降;体外血肿瘤屏障hCMEC/D3细胞中,紧密连接相关蛋白ZO-1和occludin的表达水平显著降低,在细胞膜上呈不连续分布。结论 miR-19a过表达能显著增加血肿瘤屏障的通透性,其机制之一可能与降低紧密连接相关蛋白相关。     

内耳缺血对豚鼠血迷路屏障中occludin蛋白表达的影响

目的:探讨豚鼠内耳缺血对血迷路屏障中occludin 蛋白表达的影响.方法:随机将24只豚鼠分为对照组、假手术组和缺血组.采用FeCl3诱导小脑前下动脉血栓形成制备耳蜗缺血豚鼠模型.利用激光多普勒血流测量仪检测耳蜗血流量CoBF;利用免疫组织化学染色和Western blot检测occludin蛋白表达水平的改变.结果:经激光多普勒血流测量仪检测耳蜗血流,实验组耳蜗血流量降低至手术前30%,缺血24 h后,豚鼠耳蜗组织中occludin蛋白表达水平有所降低.结论:内耳缺血会导致血迷路屏障中occludin蛋白表达下降.     

Ambient particulate matter affects occludin distribution and increases alveolar transepithelial electrical conductance

Background and objective: Inhaled particulate matter (PM) causes lung inflammation and epithelial dysfunction. However, the direct effect of PM on alveolar epithelial barrier integrity is not well understood. Our aim is to determine whether PM exposure affects the alveolar epithelial cells (AEC) transepithelial electrical conductance (Gt) and tight junction (TJ) proteins. Methods: Human AEC (A549) and primary rat AEC were exposed to PM of <10 µm in size (PM₁₀) and diesel exhaust particles (DEP), using titanium dioxide (TiO₂) as a control for particle size effects. Gt and permeability to fluorescein isothiocyanate‐dextran (FITC‐Dextran) were measured to assess barrier integrity. TJ integrity was evaluated by analysing penetration of Lanthanum nitrate (La³⁺) under transmission electron microscopy. Surface proteins were labelled with biotin and analysed by western blot. Immunofluorescence was performed to assess colocalization of TJ proteins including occludin and zonula occludens‐1 (ZO‐1). PM induced dissociation of occludin‐ZO‐1 was evaluated by co‐immunoprecipitation. Results: PM₁₀ and DEP increased Gt and disrupted TJ after 3 h of treatment. PM₁₀ and DEP induced occludin internalization from the plasma membrane into endosomal compartments and dissociation of occludin from ZO‐1. Overexpression of antioxidant enzymes manganese superoxide dismutase (MnSOD) and catalase, prevented PM‐induced Gt increase, occludin reduction from the plasma membrane and its dissociation from ZO‐1. Conclusions: PM induces alveolar epithelial dysfunction in part via occludin reduction at the plasma membrane and ZO‐1 dissociation in AEC. Furthermore, these effects are prevented by overexpression of two different antioxidant enzymes.