Effect of tight junction protein of intestinal epithelium and permeability of colonic mucosa in pathogenesis of injured colonic barrier during chronic recovery stage of rats with inflammatory bowel disease

Objective: To discuss the changes in the tight junction protein of intestinal epithelium and permeability of colonic mucosa and its possible mechanism by building the rat mode of inflammatory bowel disease at the chronic recovery stage. Methods: A total of 36 SD rats were divided into the model group and control one according to the random number table, with 18 rats in each group. Rats in the model group were given the 3% dextran sulfate sodium solution by the way of drinking for 7 d to build the rat model of inflammatory bowel disease, while rats in the control group were given free drinking of water. Six rats were executed at day 7, 14 and 21 respectively. The colonic tissues were collected from rats to observe the pathological changes of colonic mucosa. The activity of myeloperoxidase was detected and the white blood count was performed for rats in each group. The Ussing chamber technique was employed to detect the transepithelial electrical resistance(TER) and short-circuit current(SC) of colonic mucosa of rats in different time intervals; the quantum dots labeling technique was employed to detect the expression level of claudin-1 and claudin-2 in the colonic tissues. Results: After the successful modeling, the weight of rats in the model group was significantly reduced, while the disease activity index score was increased. The weight was at the lowest level at day 14 and then it began to increase afterwards. The disease activity index score was at the highest level at day 12 and then it began to decrease gradually. The activity of myeloperoxidase and WBC for rats in the model group all reached the peak value at day 14 and then decreased gradually. There was no significant difference in the changes of TER and SC in different time intervals for rats in the control group(P>0.05). TER of model group was at the lowest level at day 14 and then increased gradually; SC was at the highest level at day 14 and then decreased gradually. TER of model group at day 7, 14 and 21 was significantly lower than that of control group, while SC of model group was significantly higher than that of control group(P<0.05). There was no significant difference in the change of mean fluorescence intensity of claudin-1 and claudin-2 in different time intervals for rats in the control group(P>0.05). The claudin-1 and claudin-2 for rats in the model group reached the highest level at day 14 and then decreased gradually. The claudin-1 and claudin-2 of model group at day 7, 14 and 21 was significantly higher than that of control group(P<0.05). Conclusions: After the acute stage, the inflammatory bowel disease is then in the chronic recovery stage; the increased permeability of colonic mucosa and increased expression of tight junction protein of intestinal epithelium are closely related to the pathogenesis and development of disease. The tight junction protein plays a key role in the pathogenesis of injured colonic barrier of inflammatory bowel disease.

Transactivating-transduction protein-polyethylene glycol modified liposomes traverse the blood-spinal cord and blood-brain barriers

Naive liposomes can cross the blood-brain barrier and blood-spinal cord barrier in small amounts. Liposomes modified by a transactivating-transduction protein can deliver antibiotics for the treatment of acute bacterial infection-induced brain inflammation. Liposomes conjugated with polyethylene glycol have the capability of long-term circulation. In this study we prepared transactivating-transduction protein-polyethylene glycol-modified liposomes labeled with fiuorescein isothiocyanate. Thus, liposomes were characterized by transmembrane, long-term circulation and fluorescence tracing. Uptake, cytotoxicity, and the ability of traversing blood-spinal cord and blood-brain barriers were observed following coculture with human breast adenocarcinoma cells （MCF-7）. Results demonstrated that the liposomes had good biocompatibility, and low cytotoxicity when cocultured with human breast adenocarcinoma cells. Liposomes could traverse cell membranes and entered the central nervous system and neurocytes through the blood-spinal cord and blood-brain barriers of rats via the systemic circulation. These results verified that fluorescein isothiocyanate-modified transactivating-transduction protein-polyethylene glycol liposomes have the ability to traverse the blood-spinal cord and blood-brain barriers.

Relationship of gelatinases-tight junction proteins and blood-brain barrier permeability in the early stage of cerebral ischemia and reperfusion

Gelatinases matrix metalloproteinase-2 and matrix metalloproteinase-9 have been shown to mediate claudin-5 and occludin degradation, and play an important regulatory role in blood-brain barrier permeability. This study established a rat model of 1.5-hour middle cerebral artery occlusion with reperfusion. Protein expression levels of claudin-5 and occludin gradually decreased in the early stage of reperfusion, which corresponded to the increase of the gelatinolytic activity of matrix metalloproteinase-2 and matrix metalloproteinase-9. In addition, rats that received treatment with matrix metalloproteinase inhibitor N-[（2R）-2-（hydroxamidocarbonylmethyl）-4-methylpenthanoyl]-L- tryptophan methylamide （GM6001） showed a significant reduction in Evans blue leakage and an inhibition of claudin-5 and occludin protein degradation in striatal tissue. These data indicate that matrix metalloproteinase-2 and matrix metalloproteinase-9-mediated claudin-5 and occludin degradation is an important reason for blood-brain barrier leakage in the early stage of reperfusion. The leakage of the blood-brain barrier was present due to gelatinases-mediated degradation of claudin-5 and occludin proteins. We hypothesized that the timely closure of the structural component of the blood-brain barrier （tight junction proteins） is of importance.

黑豆-乳清双蛋白膳食对脂多糖诱导肠屏障损伤大鼠的保护作用

本研究旨在探讨黑豆-乳清双蛋白(Black Bean-Whey Double Protein, B-WDP)膳食对脂多糖(Lipopolysaccharide,LPS)诱导肠屏障损伤大鼠的保护作用,以SD大鼠为试验对象,饲喂低、中、高剂量的BW DP对其进行28 d膳食干预,随后采用脂多糖诱导大鼠肠屏障损伤。通过H&E染色观察大鼠的肠道形态、免疫组化检测紧密连接蛋白表达量、实时荧光定量PCR对TLR4、MyD88的表达水平进行测定。结果表明,与低剂量和高剂量B-W DP相比,中剂量的B-W DP能够极显著(P<0.01)地对LPS引起的肠屏障损伤起到预保护作用,使绒毛长度(Vuff Length,VL)数值增加26.69%,隐窝深度(Crypt Depth,CD)数值降低22.61%,二者比值提升了46.78%;三种剂量的B-W DP均能够对紧密连接蛋白起到不同的调节作用,中剂量干预效果最显著(P<0.01),使ZO-1、Claudin-1、Occludin的表达量分别提高了14.32%、31.80%、16.67%;三种剂量的B-W DP均能极显著(P<0.01)地抑制炎症传导途径,中剂量效果最明显,使TLR4和MyD88的表达水平分别降低了37.25%和33.04%。综上,中剂量B-W DP可改善肠道形态,提高肠道的消化吸收能力,增加紧密连接蛋白的表达量,维持上皮细胞完整,降低肠道通透性,下调TLR4和MyD88的表达水平,减轻炎症反应,对LPS诱导的肠屏障损伤产生了有效的保护作用。

四神丸改善肠道屏障功能缓解伊立替康肠道毒性的研究

目的研究四神丸对伊立替康肠道毒性的改善作用及其作用机制。方法将小鼠分为对照组,模型组(伊立替康75 mg·kg^(-1))和四神丸低、高剂量(2.5、5 g·kg^(-1))组及阳性药组(洛哌丁胺10 mg·kg^(-1))。记录小鼠体重变化,DAI评分,粪便隐血情况,结肠组织病理学变化,炎症因子肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)和白细胞介素-6(IL-6)的表达,观察四神丸对伊立替康肠道毒性的改善作用;采用灌胃FITC标记葡聚糖,4 h后检测血清中的荧光强度、脂多糖(LPS)和二胺氧化酶(DAO)含量,观察四神丸对伊立替康小鼠肠道通透性的影响;采用Western blot和免疫荧光检测小鼠结肠组织中紧密连接蛋白(ZO-1、Occludin和Claudin)的表达,观察四神丸对伊立替康小鼠肠道屏障的影响。结果与对照组比较,模型组小鼠体重明显降低,DAI评分、小鼠粪便隐血阳性率、结肠组织中炎症因子(TNF-α、IL-1β和IL-6)的表达显著升高(P<0.01);小鼠血清中荧光强度、LPS和DAO含量明显增多;小鼠结肠组织中ZO-1、Occludin和Claudin的表达显著降低(P<0.01)。四神丸低、高剂量干预后,小鼠体重显著恢复,DAI评分、小鼠粪便隐血阳性率和小鼠结肠组织中TNF-α、IL-1β、IL-6、ZO-1、Occludin和Claudin的表达明显降低(P<0.05,P<0.01);小鼠肠道通透性显著改善(P<0.01)。结论四神丸可以有效改善伊立替康的肠道毒性,其作用机制可能与促进紧密连接蛋白(ZO-1、Occludin和Claudin)的表达从而恢复肠道屏障功能有关。

星形胶质细胞在阿尔茨海默病发病机制中的研究进展

正常的星形胶质细胞是中枢神经系统的主要胶质细胞类型,可以通过多种机制参与大脑发育和成熟。在成年人的大脑中,星形胶质细胞对维持神经元环境至关重要,并参与突触间隙的神经递质循环、血脑屏障的维持和能量稳态的调节等过程。然而在阿尔茨海默病(AD)中,星形胶质细胞的功能和形态发生了显著改变,并参与疾病的发生、发展,包括产生β-淀粉样蛋白、炎症反应和胶质纤维化等。这些变化可能对神经元和突触功能造成不良影响,从而加速AD进展。该文介绍了正常的星形胶质细胞的来源、生理功能和形态特征,重点阐述其在AD中的作用和影响,并为AD的治疗提供新的方向。

绿豆蛋白对魔芋葡甘聚糖基山茶油乳液膜结构和性能的影响

为改善魔芋葡甘聚糖(konjac glucomannan,KGM)基山茶油(camellia oil,CO)乳液膜的结构和性能,添加绿豆蛋白(mung bean protein,MBP)构建KGM/可得然胶(curdlan,Cur)/MB P-CO乳液体系(KC M-CO)。KC M-CO乳液的粒径分布结果表明,MBP与K C-CO体系相容性良好,乳化液滴平均粒径下降约35.1%,K_(54) C_(40) M_(6)-CO的平均粒径最小,达32.73μm,分布均匀;扫描电镜和红外光谱分析表明,KC M-CO乳液膜的微观结构连续且致密,MBP乳化液滴均匀分布于KGM/Cur(KC)多糖网络中,以氢键相结合;MBP的添加导致乳液膜的断裂伸长率提升了27%,但拉伸强度显著下降;乳液膜表面疏水性液滴的分散性以及粗糙度的增大,导致水接触角显著提高,最高为101.4°,表现为强疏水性。随着MBP的添加,KC M-CO乳液膜的水蒸气和氧气阻隔性能显著提升,水蒸气透过系数和过氧化值分别下降了43%和52.9%,这有利于抑制果蔬贮运期间的呼吸代谢。KC M-CO乳液膜的透光率下降,有利于提升食品包装的阻光性能。KC M-CO乳液膜在食品保鲜领域有一定的应用潜力。

Effects of Lactobacillus plantarum on gut barrier function in experimental obstructive jaundice

AIM:To investigate the mechanisms of Lactobacillus plantarum(L.plantarum)action on gut barrier in preoperative and postoperative experimental obstructive jaundice in rats.METHODS:Forty rats were randomly divided into groups of sham-operation,bile duct ligation(BDL),BDL +L.plantarum,BDL+internal biliary drainage(IBD),and BDL+IBD+L.plantarum.Ten days after L.plantarum administration,blood and ileal samples were collected from the rats for morphological examination,and intestinal barrier function,liver function,intestinal oxidative stress and protein kinase C(PKC)activity measurement.The distribution and expression of the PKC and tight junction(TJ)proteins,such as occludin,zonula occludens-1,claudin-1,claudin-4,junction adhesion molecule-A and F-actin,were examined by confocal laser scanning microscopy,immunohistochemistry,Western blotting,real-time fluorescent quantitative polymerase chain reaction assay.RESULTS:L.plantarum administration substantially restored gut barrier,decreased enterocyte apoptosis,improved intestinal oxidative stress,promoted the activity and expression of protein kinase(BDL vs BDL+L.plantarum,0.295±0.007 vs 0.349±0.003,P<0.05;BDL+IBD vs BDL+IBD+L.plantarum,0.407±0.046 vs 0.465±0.135,P<0.05),and particularly enhanced the expression and phosphorylation of TJ proteins in the experimental obstructive jaundice(BDL vs BDL+L.plantarum,0.266±0.118 vs 0.326±0.009,P<0.05).The protective effect of L.plantarum was more prominent after internal biliary drainage(BDL+IBD vs BDL +IBD+L.plantarum,0.415±0.105 vs 0.494±0.145,P<0.05).CONCLUSION:L.plantarum can decrease intestinal epithelial cell apoptosis,reduce oxidative stress,and prevent TJ disruption in biliary obstruction by activating the PKC pathway.

Non-viral liposome-mediated transfer of brain-derived neurotrophic factor across the blood-brain barrier

Brain-derived neurotrophic factor（BDNF） plays an important role in the repair of central nervous system injury,but cannot directly traverse the blood-brain barrier.Liposomes are a new type of non-viral vector,able to carry macromolecules across the blood-brain barrier and into the brain.Here,we investigate whether BDNF could be transported across the blood-brain barrier by tail-vein injection of liposomes conjugated to transferrin（Tf） and polyethylene glycol（PEG）,and carrying BDNF modified with cytomegalovirus promoter（pC MV） or glial fibrillary acidic protein promoter（p GFAP）（Tf-p CMV-BDNF-PEG and Tf-p GFAP-BDNF-PEG,respectively）.Both liposomes were able to traverse the blood-brain barrier,and BDNF was mainly expressed in the cerebral cortex.BDNF expression in the cerebral cortex was higher in the Tf-p GFAP-BDNF-PEG group than in the Tf-p CMV-BDNF-PEG group.This study demonstrates the successful construction of a non-virus targeted liposome,Tf-p GFAP-BDNF-PEG,which crosses the blood-brain barrier and is distributed in the cerebral cortex.Our work provides an experimental basis for BDNF-related targeted drug delivery in the brain.

Differential expression of breast cancer-resistance protein,lung resistance protein,and multidrug resistance protein 1 in retinas of streptozotocin-induced diabetic mice

AIM：To investigate the altering expression profiles of efflux transporters such as breast cancer-resistance protein（BCRP）,lung resistance protein（LRP）,and multidrug resistance protein 1（MDR1） at the inner blood-retinal barrier（BRB） during the development of early diabetic retinopathy（DR） and/or aging in mice.METHODS：Relative m RNA and protein expression profiles of these three efflux transporters in the retina during the development of early DR and/or aging in mice were examined.The differing expression profiles of Zonula occludens 1（ ZO-1） and vascular endothelial growth factor-A（ VEGFA） in the retina as well as the perfusion characterization of fluorescein isothiocyanate（FITC）-dextran and Evans blue were examined to evaluate the integrity of the inner BRB.RESULTS：There were significant alterations in these three efflux transporters＇ expression profiles in the m RNA and protein levels of the retina during the development of diabetes mellitus and/or aging.The development of early DR was confirmed by the expression profiles of ZO-1 and VEGFA in the retina as well as the compromised integrity of the inner BRB.CONCLUSION：The expression profiles of some efflux transporters such as BCRP,LRP,and MDR1 in mice retina during diabetic and/or aging conditions are tested,and the attenuated expression of BCRP,LRP,and MDR1 along with the breakdown of the inner BRB is found,which may be linked to the pathogenesis of early DR.

Activated protein C: A regulator of human skin epidermal keratinocyte function

Activated protein C(APC) is a physiological anticoagulant, derived from its precursor protein C(PC). Independent of its anticoagulation, APC possesses strong anti-inflammatory, anti-apoptotic and barrier protective properties which appear to be protective in a number of disorders including chronic wound healing. The epidermis is the outermost skin layer and provides the first line of defence against the external environment. Keratinocytes are the most predominant cells in the epidermis and play a critical role in maintaining epidermal barrier function. PC/APC and its receptor, endothelial protein C receptor(EPCR), once thought to be restricted to the endothelium, are abundantly expressed by skin epidermal keratinocytes. These cells respond to APC by upregulating proliferation, migration and matrix metalloproteinase-2 activity and inhibiting apoptosis/inflammation leading to a wound healing phenotype. APC also increases barrier function of keratinocyte monolayers by promoting the expression of tight junction proteins and re-distributing them to cell-cell contacts. These cytoprotective properties of APC are mediated through EPCR, protease-activated receptors, epidermal growth factor receptor or Tie2. Future preventive and therapeutic uses of APC in skin disorders associated with disruption of barrier function and inflammation look promising. This review will focus on APC's function in skin epidermis/keratinocytes and its therapeutical potential in skin inflammatory conditions.

Propofol protects against blood-spinal cord barrier disruption induced by ischemia/reperfusion injury

Propofol has been shown to exert neuroprotective effects on the injured spinal cord.However,the effect of propofol on the blood-spinal cord barrier（BSCB） after ischemia/reperfusion injury（IRI） is poorly understood.Therefore,we investigated whether propofol could maintain the integrity of the BSCB.Spinal cord IRI（SCIRI） was induced in rabbits by infrarenal aortic occlusion for 30 minutes.Propofol,30 mg/kg,was intravenously infused 10 minutes before aortic clamping as well as at the onset of reperfusion.Then,48 hours later,we performed histological and m RNA/protein analyses of the spinal cord.Propofol decreased histological damage to the spinal cord,attenuated the reduction in BSCB permeability,downregulated the m RNA and protein expression levels of matrix metalloprotease-9（MMP-9） and nuclear factor-κB（NF-κB）,and upregulated the protein expression levels of occludin and claudin-5.Our findings suggest that propofol helps maintain BSCB integrity after SCIRI by reducing MMP-9 expression,by inhibiting the NF-κB signaling pathway,and by maintaining expression of tight junction proteins.

发酵枸杞多糖通过调节肠道微生态缓解葡聚糖硫酸钠诱导的溃疡性结肠炎

为探究多糖益生元调节肠道微生态作用机制,采用ELISA法、组织病理学分析、免疫组化分析、16S rRNA高通量测序、气相色谱-质谱联用等方法,研究发酵多糖对葡聚糖硫酸钠(DSS)诱导结肠炎模型小鼠肠道菌群和短链脂肪酸(SCFAs)变化的影响及其与肠道炎症水平、屏障蛋白表达的关系。结果发现,发酵枸杞多糖(FLBP)可显著降低小鼠肠道炎症水平,改善结肠组织结构,上调紧密连接蛋白Claudin-1和ZO-1表达量,同时显著增加肠道SCFAs含量。肠道菌群分析结果表明,FLBP可富集小鼠肠道杜氏芽孢杆菌(Dubosiella)和阿克曼氏菌属(Akkermansia),降低Turicibacter菌属、肠杆菌属(Faecalibaculum)、埃希氏菌-志贺菌属(Escherichia-Shigella)丰度。研究结果表明,FLBP激活重塑的杜氏芽孢杆菌在改善结肠炎中占主导作用,显著提升SCFAs含量,增强肠道屏障,降低肠道炎症。研究旨在为改善结肠炎提供更安全有益的选择,并为开发FLBP功能性食品提供理论依据。

Cinnamicaldehyde regulates the expression of tight junction proteins and amino acid transporters in intestinal porcine epithelial cells

Background： Cinnamicaldehyde（CA） is a key flavor compound in cinnamon essential oil possessing various bioactivities. Tight junction（TJ） proteins are vital for the maintenance of intestinal epithelial barrier function,transport, absorption and utilization of dietary amino acids and other nutrients. In this study, we tested the hypothesis that CA may regulate the expression of TJ proteins and amino acid transporters in intestinal porcine epithelial cells（IPEC-1） isolated from neonatal pigs.Results： Compared with the control, cells incubated with 25 μmol/L CA had increased transepithelial electrical resistance（TEER） and decreased paracellular intestinal permeability. The beneficial effect of CA on mucosal barrier function was associated with enhanced protein abundance for claudin-4, zonula occludens（ZO）-1, ZO-2, and ZO-3. Immunofluorescence staining showed that 25 μmol/L CA promoted the localization of claudin-1 and claudin-3 to the plasma membrane without affecting the localization of other TJ proteins, including claudin-4, occludin,ZO-1, ZO-2, and ZO-3, compared with the control cells. Moreover, protein abundances for rBAT, xCT and LAT2 in IPEC-1 cells were enhanced by 25 μmol/L CA, while that for EAAT3 was not affected.Conclusions： CA improves intestinal mucosal barrier function by regulating the distribution of claudin-1 and claudin-3 in enterocytes, as well as enhancing protein abundance for amino acid transporters rBAT, xCT and LAT2 in enterocytes. Supplementation with CA may provide an effective nutritional strategy to improve intestinal integrity and amino acid transport and absorption in piglets.

Protein kinases are potential targets to treat inflammatory bowel disease

Protein kinases play a crucial role in the pathogenesis of inflammatory bowel disease(IBD), the two main forms of which are ulcerative colitis and Crohn's dis-ease. In this article, we will review the mechanisms of involvement of protein kinases in the pathogenesis of and intervention against IBD, in terms of their effects on genetics, microbiota, mucous layer and tight junc-tion, and the potential of protein kinases as therapeutic targets against IBD.

治疗脾胃病的含救必应药对对溃疡性结肠炎的治疗作用

目的分析治疗脾胃病的含救必应药对对溃疡性结肠炎(UC)的治疗作用。方法(1)在中国知网数据库和万方数据知识服务平台中检索使用救必应治疗脾胃病的临床研究,收集其临床处方。应用数据挖掘技术分析治疗脾胃病的含救必应核心药对。(2)选择90只小鼠,将其随机分为正常组、模型组、救必应组及6组救必应药对组,每组10只。除正常组外,给予其余组小鼠饮用3%葡聚糖硫酸钠以建立UC模型,同时给予各给药组小鼠灌胃1.8 g/kg的相应药物,连续灌胃6 d,1次/d。在实验期间记录各组小鼠的一般症状,实验第7天观察其结肠外观、病理改变,检测其结肠组织Occludin蛋白、抗黏蛋白2(MUC2)、ATOH1蛋白的表达水平。结果(1)共获得6组含救必应的核心药对,分别为救必应-白芍、救必应-白术、救必应-茯苓、救必应-蒲公英、救必应-柴胡、救必应-党参。(2)与正常组比较,模型组小鼠的结肠长度缩短,体重下降率、疾病活动指数(DAI)及肺脏系数升高,结肠组织中MUC2、ATOH1和Occludin的蛋白表达水平降低(P<0.05)。与模型组相比,救必应-党参组小鼠体重下降率降低,救必应组、救必应-白芍组及救必应-党参组小鼠的结肠长度增加,救必应组、救必应-茯苓组及救必应-党参组小鼠的DAI降低,救必应组及救必应-白芍组小鼠的肺脏系数降低(P<0.05);救必应组及救必应-白芍组、救必应-柴胡组、救必应-党参组小鼠结肠组织黏膜下层水肿及炎症细胞浸润有所改善,救必应-白术组、救必应-茯苓组、救必应-蒲公英组小鼠结肠的黏液屏障损伤有所改善;救必应组MUC2、ATOH1和Occludin的蛋白表达水平上调,救必应-白术组、救必应-茯苓组、救必应-蒲公英组和救必应-党参组MUC2的蛋白表达水平上调,救必应-白芍能组ATOH1的蛋白表达水平上调,救必应-白术组Occludin的蛋白表达水平上调(P<0.05)。与救必应组相比,救必应-党参组的结肠长度增加,救必应-党参组及救必应-白芍药组对结肠病理改变的改善作用更为明显,救必应-白术组MUC2的蛋白表达水平更高(P<0.05)。结论救必应治疗脾胃病常用配伍药物为白芍、白术、茯苓、蒲公英、柴胡和党参。大多数含救必应药对可不同程度地改善UC小鼠模型的一般症状、病理表现及黏膜屏障蛋白的表达,其中,救必应-党参药对在改善结肠短缩及结肠病理改变方面均优于单用救必应,而救必应-白术药对在上调MUC2蛋白表达方面优于单用救必应。

黄芩苷调节cAMP/PKA/CREB信号通路对湿疹大鼠皮肤屏障功能的影响

目的探讨黄芩苷(BA)调节环磷酸腺苷(cAMP)/蛋白激酶A(PKA)/cAMP反应元件结合蛋白(CREB)通路对湿疹大鼠皮肤屏障功能的影响。方法将SD大鼠随机分为对照组(NC组)、Model组、低剂量BA组(BA-L组,25 mg/kg)、中剂量BA组(BA-M组,50 mg/kg)、高剂量BA组(BA-H组,100 mg/kg)、泼尼松组(PNS组,25 mg/kg)、BAH+cAMP抑制剂(SQ22536)组(100 mg/kg+2.13 mg/kg)、BA-H+PKA抑制剂(H-89)组(100 mg/kg+5 mg/kg),每组12只。除NC组外,其余组大鼠均构建湿疹大鼠模型。建模成功2 d后,分组进行给药处理。检测湿疹面积及严重度指数(EASI)评分、经皮肤水分流失量(TEWL)、角质层含水量(WCSC)变化;酶联免疫吸附试验(ELISA)检测大鼠血清中免疫球蛋白E(IgE)、干扰素-γ(IFN-γ)、白细胞介素-4(IL-4)水平及大鼠背部受试区皮损组织中c AMP蛋白表达;HE染色检测大鼠背部受试区皮损组织病理变化;Western blot检测大鼠背部受试区皮损组织中水通道蛋白3(AQP3)、cathelicidin相关抗菌肽(CRAMP)、p-PKA、p-CREB蛋白表达。结果与NC组比较,Model组大鼠背部受试区皮损组织病理损伤严重,EASI评分、TEWL、IgE、IL-4水平升高,WCSC、IFN-γ水平、AQP3、CRAMP、cAMP、p-PKA、p-CREB蛋白水平降低(P<0.05)。与Model组比较,BA-L组、BA-M组、BA-H组、PNS组大鼠背部受试区皮损组织病理损伤减轻,EASI评分、TEWL、IgE、IL-4水平降低,WCSC、IFN-γ水平、AQP3、CRAMP、cAMP、p-PKA、p-CREB蛋白水平升高(P<0.05);且BA-L组、BA-M组、BA-H组上述指标变化呈剂量依赖性。SQ22536或H-89减弱了高剂量BA对湿疹大鼠皮肤屏障功能的改善作用。结论BA可能通过激活cAMP/PKA/CREB信号通路改善湿疹大鼠皮肤屏障功能。

Hyperoside protects the blood-brain barrier from neurotoxicity of amyloid beta 1–42

Mounting evidence indicates that amyloid β protein（Aβ） exerts neurotoxicity by disrupting the blood-brain barrier（BBB） in Alzheimer＇s disease. Hyperoside has neuroprotective effects both in vitro and in vivo against Aβ. Our previous study found that hyperoside suppressed Aβ1-42-induced leakage of the BBB, however, the mechanism remains unclear. In this study, bEnd.3 cells were pretreated with 50, 200, or 500 μM hyperoside for 2 hours, and then exposed to Aβ1-42 for 24 hours. Cell viability was determined using 3-（4,5-dimethyl-2-thiazolyl）-2,5-diphenyl-2-H-tetrazolium bromide assay. Flow cytometry and terminal deoxynucleotidyl transferase-mediated d UTP nick-end labeling assay were used to analyze cell apoptosis. Western blot assay was carried out to analyze expression levels of Bax, Bcl-2, cytochrome c, caspase-3, caspse-8, caspase-9, caspase-12, occludin, claudin-5, zonula occludens-1, matrix metalloproteinase-2（MMP-2）, and MMP-9. Exposure to Aβ1-42 alone remarkably induced bEnd.3 cell apoptosis; increased ratios of cleaved caspase-9/caspase-9, Bax/Bcl-2, cleav ed caspase-8/caspase-8, and cleaved caspase-12/caspase-12; increased expression of cytochrome c and activity of caspase-3; diminished levels of zonula occludens-1, claudin-5, and occludin; and increased levels of MMP-2 and MMP-9. However, hyperoside pretreatment reversed these changes in a dose-dependent manner. Our findings confirm that hyperoside alleviates fibrillar Aβ1-42-induced BBB disruption, thus offering a feasible therapeutic application in Alzheimer＇s disease.

Bioabsorbable Barrier Membrane Combined with rhBMP-2 Improved Bone Formation in an Experimental Model of Compromised Healing But Was Not Superior to rhBMP-2 Alone

Objective: Bioabsorbable barrier membranes placed over alveolar ridge bone defects are routinely used in dental surgery to promote bone formation. Combining these osteoconductive membranes with osteoinductive Bone Morphogenetic Proteins could prove useful in long bone fracture treatment. The hypothesis was tested in a clinically relevant model of compromised healing. Methods: Four groups of 8 rabbits underwent unilateral mid-tibial osteotomy, excision of periosteum and endosteum, and plate fixation. One group had rhBMP-2 deposited between the bone ends and Membrane wrapped around the osteotomy, the second group had Membrane wrapped around the osteotomy, the third group had rhBMP-2 placed between the bone ends, and the fourth group received no additional treatment. Results: After 7 weeks, callus size and blood flow were significantly higher in the Membrane+rhBMP-2 group than in the rhBMP-2 treated group, but torsion to failure test showed no significant difference. Membrane treatment and no treatment led to non-union. Conclusion: Absorbable barrier membrane combined with rhBMP-2 enhances bone formation, but has no advantage to rhBMP-2 alone. Membrane alone wrapped around the osteotomy was unable to prevent non-union formation.

VSAP磷酸化介导紧密连接蛋白参与保护脓毒症肠上皮屏障功能

目的:验证紧密连接蛋白ZO-1、Claudin-5和Occludin保护脓毒症肠屏障功能与血管扩张刺激磷蛋白(vasodilator-stimulated phosphoprotein, VASP)相关。方法:盲肠结扎穿孔术构建脓毒症小鼠模型,实验分为:对照组、假手术组、模型组和VASP磷酸化(p-VASP)激动剂Bucladesine组。ELISA检测血清中二胺氧化酶(DAO)和D-乳酸(D-LA)含量。HE染色观察小肠黏膜组织形态。TUNEL染色检测小肠上皮细胞凋亡。Western blotting检测Bax、Bcl-2、p-VASP、ZO-1、Occludin和claudin-5蛋白表达水平。结果:与对照组和假手术组相比,模型组中小肠绒毛数量减少、绒毛断裂、TUNEL阳性细胞增加、DAO和D-LA含量升高(P<0.05),Bax蛋白、p-VASP蛋白表达水平升高(P<0.05),ZO-1、Occludin和claudin-5蛋白、Bcl-2蛋白表达水平降低(P<0.05)。与模型组相比,Bucladesine组中小肠绒毛数量增加、绒毛断裂减少、TUNEL阳性细胞减少、DAO和D-LA含量降低(P<0.05),p-VASP蛋白表达水平降低(P<0.05),ZO-1、Occludin和claudin-5蛋白表达水平升高(P<0.05)。结论:抑制脓毒症小鼠p-VASP后小肠上皮屏障功能恢复,这与上调紧密连接蛋白表达水平有关。