胰岛素对糖尿病大鼠下颌下腺Bcl-2和Caspase-3表达的影响及意义

目的观察胰岛素对糖尿病大鼠下颌下腺内凋亡相关蛋白Bcl-2和Caspase-3表达的影响。方法 SD大鼠30只,随机分为3组,10只大鼠作为对照组(C);10只大鼠用链尿佐菌素复制糖尿病模型作为DM组;10只大鼠用链尿佐菌素复制糖尿病模型,予以胰岛素治疗作为INS组。2个月后取血检测血糖、血脂;取大鼠下颌下腺,分别进行免疫组织化学显色(SP法)和计算机图像分析系统测平均光密度。结果①血糖检测结果:C组和INS组的血糖分别与DM组血糖比较,均有差异(P0.05);②血脂检测结果:C组和INS组的TG分别与DM组TG比较,均有显著性差异(P0.05);DM组TC分别与C组和INS组TC比较,均有显著性差异(P0.05)。③免疫组化结果:与C组比较,DM组大鼠下颌下腺导管上皮细胞内Bcl-2表达显著下降(P0.05),Caspase-3表达显著增加(P0.05);与DM组比较,胰岛素组Bcl-2表达显著增加(P0.05),Caspase-3表达显著下降(P0.05)。结论 DM大鼠下颌下腺内Bcl-2表达降低和Caspase-3表达增加,可能在糖尿病时下颌下腺细胞凋亡过程中发挥重要作用,而胰岛素具有对抗糖尿病下颌下腺细胞凋亡的作用。     

牦牛水通道蛋白AQP1和AQP3基因克隆及在不同组织中表达和定位

水通道蛋白(Aquaporin,AQP)广泛存在于生物体的各组织部位,影响着生物体水代谢的过程.为进一步研究水通道蛋白1(AQP1)和水通道蛋白3(AQP3)生物学功能,本文对牦牛(Bos grunniens)不同组织中 AQP1和AQP3基因的表达与定位进行了研究.采用PCR方法扩增牦牛AQP1和AQP3基因,对其序...     

胰岛素对糖尿病大鼠下颌下腺内NGF及VEGF表达的影响

目的观察神经生长因子(NGF)及血管内皮生长因子(VEGF)在糖尿病大鼠下颌下腺内表达变化,探讨胰岛素对其表达影响及可能机制。方法 SD大鼠30只,随机分为:对照组、糖尿病组、胰岛素治疗组。大鼠2个月成模后,取血检测血糖;取下颌下腺组织,分别进行HE染色、免疫组织化学染色和计算机图像分析。结果①对照组血糖与糖尿病组比较差异有统计学意义;胰岛素治疗组血糖与糖尿病组比较差异有统计学意义。②糖尿病组腺泡轻度萎缩,排列不规则,颗粒曲管数目减少,直径变小;胰岛素治疗组较对照组变化不明显。③与对照组相比较,糖尿病组NGF表达下调,VEGF表达上调。与糖尿病组相比较,胰岛素治疗组NGF表达上调,VEGF表达下调。结论糖尿病大鼠下颌下腺内NGF表达减少、VEGF表达增高,可能是糖尿病患者神经病变与血管病变的重要原因之一;胰岛素治疗可能与NGF和VEGF的表达改变有内在联系。     

吸烟大鼠肺脏AQP4和MUC5AC的表达及其与一氧化氮的关系

目的：研究烟草烟雾吸入对大鼠肺组织水通道蛋白4（AQP4）和粘蛋白5AC（MUC5AC）表达的影响及其与支气管肺泡灌洗液内一氧化氮代谢物水平的关系,探讨氧化应激对肺部水转运和粘液分泌的影响。方法：免疫组化法观察AQP4在肺组织内的表达,平均光密度法比较模型组和空白组大鼠AQP4的表达差异;半定量RT—PCR法检测肺组织内AQP4及MUC5ACmRNA的表达水平;硝酸还原酶法测定各组大鼠支气管肺泡灌洗液内一氧化氮代谢产物的浓度,分析模型组AQP4、MUC5ACmRNA的表达水平与支气管肺泡灌洗液内一氧化氮代谢物浓度之间的相关关系：结果：AQP4在空白对照组呈强阳性染色,在模型组呈弱阳性染色,两者平均光密度值有显著差异（P〈0．05）。模型组动物肺组织AQP4mRNA的表达降低,MUC5ACmRNA的表达升高,与空白组比较均有显著差异（P〈0．05）,模型组动物支气管肺泡灌洗液内一氧化氮代谢产物的浓度与肺组织AQP4mRNA表达水平呈负相关,相关系数r=-0．798,（P〈0．05）,与MUC5ACmRNA的表达水平呈正相关,相关系数r=0．857,（P〈0．05）。结论：吸烟可导致肺组织AQP4表达下降进而影响气道内水的转运。一氧化氮可能参与了烟雾吸入动物模型中AQP4与MUC5AC基因袁达的调控．     

吸烟大鼠肺脏AQP4 和MUC5AC 的表达及其与 一氧化氮的关系

目的:研究烟草烟雾吸入对大鼠肺组织水通道蛋白4(AQP4)和粘蛋白5AC(MUC5AC)表达的影响及其与支气管肺泡灌洗液内一氧化氮代谢物水平的关系,探讨氧化应激对肺部水转运和粘液分泌的影响。方法:免疫组化法观察AQP4在肺组织内的表达,平均光密度法比较模型组和空白组大鼠AQP4的表达差异;半定量RT-PCR法检测肺组织内AQP4及MUC5AC mRNA的表达水平;硝酸还原酶法测定各组大鼠支气管肺泡灌洗液内一氧化氮代谢产物的浓度,分析模型组AQP4、MUC5AC mRNA的表达水平与支气管肺泡灌洗液内一氧化氮代谢物浓度之间的相关关系。结果:AQP4在空白对照组呈强阳性染色,在模型组呈弱阳性染色,两者平均光密度值有显著差异(P<0.05)。模型组动物肺组织AQP4 mRNA的表达降低,MUC5AC mRNA的表达升高,与空白组比较均有显著差异(P<0.05),模型组动物支气管肺泡灌洗液内一氧化氮代谢产物的浓度与肺组织AQP4 mRNA表达水平呈负相关,相关系数r=-0.798(,P<0.05),与MUC5AC mRNA的表达水平呈正相关,相关系数r=0.857(,P<0.05)。结论:吸烟可导致肺组织AQP4表达下降进而影响气道内水的转运。一氧化氮可能参与了烟雾吸入动物模型中AQP4与MUC5AC基因表达的调控。     

急性酒精中毒合并中度创伤性脑损伤大鼠海马AQP4的表达

目的:探讨大鼠急性酒精中毒合并颅脑外伤后AQP4在海马区表达的变化.方法:健康成年雄性SD大鼠96只,随机分为4组:假手术组(N组)、急性酒精中毒组(A组)、中度创伤性脑损伤组(T组)和急性酒精中毒合并中度创伤性脑损伤(AT组).腹腔注射酒精(2.5g/kg),2h后以重物自由落体击打大鼠头部建立急性酒精中毒合并中度创伤性脑损伤(traumatic brain injury,TBI)动物模型.各组动物分别存活1、3、5、14天.免疫组化方法检测海马CA1区AQP4的表达.结果:AQP4阳性产物分布于胶质纤维和毛细血管壁,各实验组表达均高于N组.术后1天T组比AT组表达显著增高(P＜0.01),术后3天AT组比T组表达增高(P＜0.05),术后14天AT组比T组表达显著增高(P＜0.01).结论:大鼠急性酒精中毒合并颅脑外伤后晚期,海马CA1区AQP4表达增高,可能加重晚期继发性脑水肿,是急性酒精中毒合并颅脑外伤预后不良的原因之一.     

急性酒精中毒合并中度创伤性脑损伤大鼠海马AQP4的表达

目的:探讨大鼠急性酒精中毒合并颅脑外伤后AQP4在海马区表达的变化.方法:健康成年雄性SD大鼠96只,随机分为4组:假手术组(N组)、急性酒精中毒组(A组)、中度创伤性脑损伤组(T组)和急性酒精中毒合并中度创伤性脑损伤(AT组).腹腔注射酒精(2.5g/kg),2h后以重物自由落体击打大鼠头部建立急性酒精中毒合并中度创伤性脑损伤(traumatic brain injury,TBI)动物模型.各组动物分别存活1、3、5、14天.免疫组化方法检测海马CAI区AQP4的表达.结果:AQP4阳性产物分布于胶质纤维和毛细血管壁,各实验组表达均高于N组.术后1天T组比AT组表达显著增高(P＜0.01),术后3天AT组比T组表达增高(P＜0.05),术后14天AT组比T组表达显著增高(P＜0.01).结论:大鼠急性酒精中毒合并颅脑外伤后晚期,海马CAI区AQP4表达增高,可能加重晚期继发性脑水肿,是急性酒精中毒合并颅脑外伤预后不良的原因之一.     

AQP1真核表达载体的构建及其在FRT细胞的表达

目的：构建小鼠AQP1基因真核表达质粒并观察其在FRT细胞中的表达。方法：采用RT—PCR方法从小鼠肾脏组织的总cDNA中扩增出小鼠的AQP1基因,采用基因重组技术将AQP1的cDNA片段插入真核表达载体pCAGGS,构建小鼠AQP1的真核表达质粒,脂质体转染FRT细胞进行表达。结果：酶切和测序结果证实AQP1真核表达质粒构建成功,经脂质体转染FRT细胞后,免疫荧光检测证明AQPI蛋白在真核细胞中成功表达。结论：成功构建真核表达质粒pCAGGS—AQP1-myc,并在FRT细胞中得以表达。为进一步研究小鼠AQP1过表达时的功能及机制奠定了实验基础。     

急性酒精处理对大鼠脑内AQP4表达的影响

目的:探讨急性酒精处理对大鼠脑内水通道蛋白4(aquaporin-4,AQP4)表达变化的影响。方法:32只雄性SD成年大鼠随机分为低剂量酒精组(LA)、中剂量酒精组(MA)、高剂量酒精组(HA)和生理盐水对照组(NS)。其中前三组通过腹腔注射不同剂量的酒精制作大鼠急性酒精中毒模型,生理盐水对照组腹腔注射等剂量的生理盐水。免疫组化方法检测了脑内前额皮质、胼胝体和室管膜AQP4的表达变化。结果:AQP4表达于各组大鼠的前额皮质、胼胝体和室管膜,LA组平均相对灰度值(ARG)分别为1．455±0．142,1．583±0．114,1．422±0．111,HA组ARG值分别为1．432±0．131,1．567±0．143,1．412±0．119,均高于NS组ARG值1．414±0．119,1．523±0．123,1．402±0．128(P＜0．05),MA组AQP4阳性表达显著增强,ARG值1．602±0．124,1．595±0．149,1．433±0．008,明显高于NS组ARG值1．414±0．119,1．523±0．123,1．402±0．128(p＜0．01)。结论:急性酒精中毒能使大鼠脑内AQP4表达显著增加,其表达的变化可能与急性酒精中毒时脑水肿有关。     

5-HT受体亚型在大鼠颌下腺的免疫组织化学定位及5-HT的功能研究

目的 研究探讨了大鼠颌下腺中5-羟钩胺受体亚型的分布以及5-HT功能。方法 免疫组织化学法和免疫酶联检测法,结果 大鼠颌下腺的浆液性腺泡上皮细胞,闰管,颗粒曲管,纹状管和排泄管的管壁上皮细胞均呈5-HT1AR离体培养的颌下腺分泌神经生长因子（NGF）,但是,当外源5-HT浓度大于10^-7时却抑制NGF的分泌。结论 提示5-HT对颌下腺NGF的分泌可能起双向调节的作用。     

Topiramate reduced sweat secretion and aquaporin-5 expression in sweat glands of mice

Decreased sweat secretion is a primary side effect of topiramate in pediatric patients, but the mechanism underlying this effect remains unclear. This study aimed to better understand how topiramate decreases sweat secretion by examining its effect on the expression of carbonic anhydrase (CA) II and aquaporin-5 (AQP5), total CA activity, as well as on tissue morphology of sweat glands in mice. Both developing and mature mice were treated with a low (20 mg/kg/day) and high dose (80 mg/kg/day) of topiramate for 4 weeks. Sweat secretion was investigated by an established technique of examining mold impressions of hind paws. CA II and AQP5 expression levels were determined by immunofluorescence and immunoblotting and CA activity by a colorimetric assay. In mature mice, topiramate treatment decreased the number of pilocarpine reactive sweat glands from baseline in both the low and high dose groups by 83% and 75%, respectively. A similar decrease was seen in developing mice. Mature mice with reactive sweat glands that declined more than 25% compared to baseline were defined as anhidrotic mice. These mice did not differ from controls in average secretory coil diameter, CA II expression and CA activity. In contrast, anhidrotic mice did show a reduction in membrane AQP5 expression in sweat glands after topiramate delivery. Thus, sweat secretion and membrane AQP5 expression in mouse sweat glands decreased following topiramate administration. These results suggest dysregulation of AQP5 may be involved in topiramate-induced hypohidrosis and topiramate may serve as a novel therapy for hyperhidrosis.     

Histological observations on the effects of isoproterenol on regenerating submandibular glands of the rat

Summary The effect of isoproterenol (IPR) on acinar cell mitoses was studied in regenerating submandibular glands of the rat following partial extirpation. In controls, mitoses of acinar cells were markedly higher on the cut surface (reactive zone) than in the remainder of the gland through 10 ds post-operation. In experimental animals by 5 ds, a burst of mitoses of acinar cells was seen in all areas of the gland except the reactive zone. In the reactive zone, IPR appears to suppress or inhibit the induced mitoses seen in controls.This study was supported by NIDR Grant # DE 05072-02     

Single intravenous injection of plasmid DNA encoding human paraoxonase-1 inhibits hyperlipidemia in rats

Paraoxonase-1 (PON1, EC 3.1.8.1) is a high-density lipoprotein (HDL)-associated antioxidant enzyme, and its activity correlates negatively with the level of plasma low-density lipoprotein cholesterol (LDL-C) and triglyceridemia (TG). In this study, we examined the therapeutic effect of plasmid DNA containing the human PON1 gene (pcDNA/PON1) in hyperlipidemic model rats. The rats were fed a high-fat and high-cholesterol diet for 25 days to produce a hyperlipidemic animal model. Single intravenous injection of pcDNA/PON1 into model rats prevented dyslipidemia and hepatic lipid accumulation. The mechanisms of pcDNA/PON1 in treating hyperlipidemia were associated with increases of serum antioxidant PON1 and SOD activities, and with reduction of the levels of total cholesterol (TC), LDL-C and TG. The results suggest the potential therapeutic effect of pcDNA/PON1 on hyperlipidemia.     

Effect of lipid lowering tablet on blood lipid in hyperlipidemia model rats

Observe the effect of lipid-lowering tablets on body weight, liver index and serum biochemical indexes of hyperlipidemia rats. The hyperlipidemia rat model was replicated successfully. Compared with the model group, high, medium and low dose lipid-lowering tablets group could significantly increase the body weight of rats with hyperlipidemia (P?<?0.01, P?<?0.05); High and middle dose lipid-lowering tablets group could significantly reduce the liver index of high fat rat (P?<?0.01); High, medium and low dose lipid-lowering tablets group could significantly decrease levels of TC, TG, LDL-C, AST, ALT, ALP, Y-GT in serum (P?<?0.01, P?<?0.05), and significantly increase the level of HDL-C (P?<?0.01). Lipid-lowering tablets can effectively regulate the body lipid metabolism of rats, and have a certain therapeutic effect on hyperlipidemia.     

Aquaporin-5 water channel in lipid rafts of rat parotid glands

Aquaporin-5 (AQP5), an apical plasma membrane (APM) water channel in salivary glands, lacrimal glands, and airway epithelium, has an important role in fluid secretion. The activation of M3 muscarinic acetylcholine receptors (mAChRs) or α1-adrenoceptors on the salivary glands induces salivary fluid secretion. AQP5 localizes in lipid rafts and activation of the M3 mAChRs or α1-adrenoceptors induced its translocation together with the lipid rafts to the APM in the interlobular ducts of rat parotid glands. This review focuses on the mechanisms of AQP5 translocation together with lipid rafts to the APM in the interlobular duct cells of parotid glands of normal rats and the impairment of AQP5 translocation in diabetes and senescence.     

Seasonal effect in expression of AQP1, AQP3 and AQP5 in skin of Murrah buffaloes

Aquaporins are transmembrane protein channels which are known to help the passage of water and solutes across the cell membranes. AQP1, AQP3 and AQP5 are isoforms of aquaporin known to aid in transepithelial water movement. AQP3 is also known to aid in glycerol transport. The present study was conducted to investigate the role of AQP1, AQP3 and AQP5 in thermoregulation of buffaloes by probing the expression of the genes in skin of buffaloes during different season viz. winter, spring and summer. The skin tissue samples were collected from the neck region of Murrah buffaloes (n = 12) and analyzed for gene expression by RT-PCR and immunolocalization. The physiological responses including respiration rate, rectal temperature and neck skin temperature observed during summer were significantly higher than winter and spring seasons. The study revealed the expression of AQP1, AQP3 and AQP5 genes in skin samples. The relative mRNA expressions of AQP1, AQP3 and AQP5 in skin relative to spring season were 1.41 ± 0.47, 1.95 ± 0.22 and 6.77 ± 1.02 folds during summer which were significantly higher than other seasons. The up-regulation of the expression of the studied AQPs were concomitant with the increase in physiological responses including skin temperature and sweating rate during summer. During summer season, AQP1 were mostly immunolocalized in the walls of skin blood capillaries, while AQP3 were observed mostly in the epidermal layer of the skin. The immunolocalization of AQP5 were mostly observed in the secretory glands of skin. The up-regulation of AQP1, AQP3 and AQP5 in skin during summer season indicates their role in thermoregulation of buffaloes.     

Transfer of the AQP1 cDNA for the correction of radiation-induced salivary hypofunction

The treatment of most patients with head and neck cancer includes ionizing radiation (IR). Salivary glands in the IR field suffer significant and irreversible damage, leading to considerable morbidity. Previously, we reported that adenoviral (Ad)-mediated transfer of the human aquaporin-1 (hAQP1) cDNA to rat [C. Delporte, B.C. O'Connell, X. He, H.E. Lancaster, A.C. O'Connell, P. Agre, B.J. Baum, Increased fluid secretion after adenoviral-mediated transfer of the aquaporin-1 cDNA to irradiated rat salivary glands. Proc. Natl. Acad. Sci. U S A. 94 (1997) 3268-3273] and miniature pig [Z. Shan, J. Li, C. Zheng, X. Liu, Z. Fan, C. Zhang, C.M. Goldsmith, R.B. Wellner, B.J Baum, S. Wang. Increased fluid secretion after adenoviral-mediated transfer of the human aquaporin-1 cDNA to irradiated miniature pig parotid glands. Mol. Ther. 11 (2005) 444-451] salivary glands ∼16 weeks following IR resulted in a dose-dependent increase in salivary flow to ≥80% control levels on day 3. A control Ad vector was without any significant effect on salivary flow. Additionally, after administration of Ad vectors to salivary glands, no significant lasting effects were observed in multiple measured clinical chemistry and hematology values. Taken together, the findings show that localized delivery of AdhAQP1 to IR-damaged salivary glands is useful in transiently increasing salivary secretion in both small and large animal models, without significant general adverse events. Based on these results, we are developing a clinical trial to test if the hAQP1 cDNA transfer strategy will be clinically effective in restoring salivary flow in patients with IR-induced parotid hypofunction.     

Inhibition and transcriptional silencing of a subtilisin-like proprotein convertase, PACE4/SPC4, reduces the branching morphogenesis of and AQP5 expression in rat embryonic submandibular gland

The submandibular gland (SMG) develops through the epithelial-mesenchymal interaction mediated by many growth/differentiation factors including activin and BMPs, which are synthesized as inactive precursors and activated by subtilisin-like proprotein convertases (SPC) following cleavage at their R-X-K/R-R site. Here, we found that Dec-RVKR-CMK, a potent inhibitor of SPC, inhibited the branching morphogenesis of the rat embryonic SMG, and caused low expression of a water channel AQP5, in an organ culture system. Dec-RVKR-CMK also decreased the expression of PACE4, a SPC member, but not furin, another SPC member, suggesting the involvement of PACE4 in the SMG development. Heparin, which is known to translocate PACE4 in the extracellular matrix into the medium, and an antibody specific for the catalytic domain of PACE4, both reduced the branching morphogenesis and AQP5 expression in the SMG. The inhibitory effects of Dec-RVKR-CMK were partially rescued by the addition of recombinant BMP2, whose precursor is one of the candidate substrates for PACE4 in vivo. Further, the suppression of PACE4 expression by siRNAs resulted in decreased expression of AQP5 and inhibition of the branching morphogenesis in the present organ culture system. These observations suggest that PACE4 regulates the SMG development via the activation of some growth/differentiation factors.