脊髓半横断损伤后腹角神经元神经生长因子、脑源性神经营养因子、神经营养因子-3和神经营养因子-4表达的变化

目的:探讨大鼠脊髓半横断损伤(htSCI)后脑源性神经营养因子(BDNF)、神经生长因子(NGF)、神经营养因子(NT-3、NT-4)在脊髓腹角神经元表达的早期变化。方法:免疫组织化学ABC法分别染4种神经因子并作阳性细胞计数。结果:NGF主要分布于脊髓腹角神经元的胞核,BDNF、NT-4与NT-3主要分布于胞浆。htSCI前后它们在细胞内的分布范围没有变化。BDNF、NGF与NT-3的3 d在损伤尾侧段脊髓双侧腹角阳性神经元数与对照组相比显著减少。BDNF与NGF的14 d的双侧腹角阳性神经元数量均较正常组明显增多,NT-3与NT-4的14 d~21 d的双侧腹角阳性神经元数量均较正常组明显增多,BDNF7~21 d以及NGF14 d的健侧的阳性神经元数量均分别多于相应的伤侧。结论:内源性BDNF、NGF、NT-3、NT-4增加对脊髓损伤修复具有重要作用,BDNF和NGF在健侧表达的增加说明健侧代偿功能的活跃。     

Leukaemia inhibitory factor receptor and gp130 in the human Fallopian tube and endometrium before and after mifepristone treatment and in the human preimplantation embryo

Leukaemia inhibitory factor (LIF) is a cytokine, which is associated with reproductive processes such as embryo development and implantation. The objectives of this study were to detect the presence of LIF receptor (LIFR) and glycoprotein 130 (gp 130) in the human Fallopian tube, endometrium and preimplantation embryo and to study the effect of mifepristone on the expression of LIFR and gp130 in the Fallopian tube. Twenty-two healthy fertile women received a single dose of 200 mg mifepristone or placebo immediately after ovulation (LH + 2). Biopsies were obtained from the Fallopian tubes during laparoscopic sterilization once between days LH + 4 and LH + 6 and from endometrium once between days LH + 6 and LH + 8. Preimplantation embryos were received from couples undergoing in vitro fertilization treatment. Immunohistochemistry was used to detect the presence of LIFR and gp130 in the Fallopian tube, endometrium and preimplantation embryo. Real-time PCR was used to study LIFR and gp130 expression in the Fallopian tube and endometrium. LIFR and gp130 were localized in the Fallopian tube, preimplantation embryo and endometrium. LIFR was more abundant in the Fallopian tube than in the endometrium. In the blastocyst, the staining of gp130 was mainly localized in the inner cell mass, whereas LIFR was expressed in all cells. The presence of LIFR and gp130 in the Fallopian tube and preimplantation embryo indicates a role for LIF in communication between the embryo and the Fallopian tube. Mifepristone did not affect the expression of LIFR and gp130 in the Fallopian tube, nor in the endometrium suggesting that progesterone might not be directly involved in the regulation of LIFR or gp130.     

Cardiotrophin-1 and the role of gp130-dependent signaling pathways in cardiac growth and development

 The reactivation of an embryonic pattern of gene expression is a central feature common to virtually all forms of cardiac hypertrophy. Unraveling the regulatory mechanisms, growth factors and cytokines controlling gene expression and cell fate during cardiac development may therefore have implications for our understanding of cardiac hypertrophy in the adult. Along this line, a cDNA expression library was established from an embryonic stem cell-based in vitro model of cardiogenesis, and screened for clones that would induce an increase in cell size in cultured cardiomyocytes. This experimental strategy resulted in the isolation of a novel cytokine, cardiotrophin-1 (CT-1), that activates several features of cardiomyocyte hypertrophy in vitro, including sarcomeric organization and embryonic gene expression. CT-1 displays structural similarities to the interleukin (IL)-6 related cytokines. Furthermore, receptor binding studies and functional studies reveal that CT-1 shares the signal transducing receptor components gp130 and LIFR with the previously identified members of the IL-6 cytokine family. CT-1 rapidly activates gp130 and LIFR tyrosine phosphorylation in cultured cardiac myocytes. The growth promoting effects of CT-1 therefore indicate that signaling pathways emanating from gp130 and LIFR are coupled to cardiomyocyte hypertrophy. In support of this notion, the simultaneous overexpression of IL-6 and the IL-6 receptor in transgenic mice has been shown to result in a constitutive tyrosine phosphorylation of gp130 in the myocardium and cardiac hypertrophy. The striking phenotype of gp130 null-mutant mice, generated by homologous recombination, implies gp130 in cardiac development as well: mutant mice exhibit severe ventricular hypoplasia, suggesting a role for gp130-dependent signaling pathways in the expansion of the compact layer of the ventricular myocardium. CT-1 is expressed at high levels in the myocardium during the course of cardiogenesis, and promotes the proliferation and survival of embryonic cardiomyocytes. CT-1 may therefore represent a candidate cytokine to activate gp130 during cardiac development. In summary, cytokines signaling through gp130 are emerging as potent regulators of embryonic heart development and adult cardiac hypertrophy. Received: 1 January 1997 / Accepted: 14 March 1997     

DHEA improves impaired activation of Akt and PKC ζ/λ‐GLUT4 pathway in skeletal muscle and improves hyperglycaemia in streptozotocin‐induced diabetes rats

Aim: Addition of dehydroepiandrosterone (DHEA) to a cultured skeletal muscle locally synthesizes 5α‐dihydrotestosterone (DHT). It induced activation of glucose metabolism‐related signalling pathway via protein kinase B (Akt) and protein kinase C zeta/lambda (PKC ζ/λ)‐glucose transporter‐4 (GLUT4) proteins. However, such an effect of DHEA in vivo remains unclear. Methods: Using streptozotocin (STZ)‐induced rats with type 1 diabetes mellitus, we tested the hypothesis that a single bout of DHEA injection in the rats improves hyperglycaemia and muscle GLUT4‐regulated signalling pathway. After 1 week of STZ injection (55 mg kg^?1) with male Wistar rats, fasting glucose concentrations were determined in a blood sample taken from the tail vein. Blood glucose levels were then monitored for 180 min after DHEA or sesame oil (control) was injected (n = 10 for each group). Results: Blood glucose levels decreased significantly for 30–150 min after 2 mg DHEA injection in the STZ rats. In the skeletal muscle, expression and translocation of GLUT4 protein, phosphorylation of Akt and PKC ζ/λ, and phosphofructokinase and hexokinase enzyme activities increased significantly by DHEA injection. However, DHEA‐induced improvements in Akt and PKC ζ/λ‐GLUT4 pathways were blocked by a DHT inhibitor. Conclusion: These results suggest that a single bout of DHEA injection can improve hyperglycaemia and activate the glucose metabolism‐related signalling pathway via Akt and PKC ζ/λ‐GLUT4 proteins of skeletal muscles in rats. Moreover, these results show that a DHEA‐induced increase in muscle glucose uptake and utilization might contribute to improvement in hyperglycaemia in type 1 diabetes mellitus.     

Neurotrophic modulation of myelinated cutaneous innervation and mechanical sensory loss in diabetic mice

Human diabetic patients often lose touch and vibratory sensations, but to date, most studies on diabetes-induced sensory nerve degeneration have focused on epidermal C-fibers. Here, we explored the effects of diabetes on cutaneous myelinated fibers in relation to the behavioral responses to tactile stimuli from diabetic mice. Weekly behavioral testing began prior to streptozotocin (STZ) administration and continued until 8 weeks, at which time myelinated fiber innervation was examined in the footpad by immunohistochemistry using antiserum to neurofilament heavy chain (NF-H) and myelin basic protein (MBP). Diabetic mice developed reduced behavioral responses to non-noxious (monofilaments) and noxious (pinprick) stimuli. In addition, diabetic mice displayed a 50% reduction in NF-H-positive myelinated innervation of the dermal footpad compared with non-diabetic mice. To test whether two neurotrophins nerve growth factor (NGF) and/or neurotrophin-3 (NT-3) known to support myelinated cutaneous fibers could influence myelinated innervation, diabetic mice were treated intrathecally for 2 weeks with NGF, NT-3, NGF and NT-3. Neurotrophin-treated mice were then compared with diabetic mice treated with insulin for 2 weeks. NGF and insulin treatment both increased paw withdrawal to mechanical stimulation in diabetic mice, whereas NT-3 or a combination of NGF and NT-3 failed to alter paw withdrawal responses. Surprisingly, all treatments significantly increased myelinated innervation compared with control-treated diabetic mice, demonstrating that myelinated cutaneous fibers damaged by hyperglycemia respond to intrathecal administration of neurotrophins. Moreover, NT-3 treatment increased epidermal Merkel cell numbers associated with nerve fibers, consistent with increased numbers of NT-3-responsive slowly adapting A-fibers. These studies suggest that myelinated fiber loss may contribute as significantly as unmyelinated epidermal loss in diabetic neuropathy, and the contradiction between neurotrophin-induced increases in dermal innervation and behavior emphasizes the need for multiple approaches to accurately assess sensory improvements in diabetic neuropathy.     

Endotoxemia enhances expression of the signaling receptor (GP130) on protein and molecular level

Interleukin 6 (IL-6) performs a prominent role during sepsis. To examine the molecular regulation of IL-6, IL-6 receptor, and signaling receptor gp130 during endotoxemia, nine healthy young volunteers received a bolus injection of lipopolysaccharide (LPS) on day 1 and saline on day 2 in a double blind, randomized, placebo-controlled trial. LPS enhanced IL-6 release 300-fold. IL-6 mRNA expression was not significantly altered in blood samples at any time after LPS infusion in vivo, while incubation of whole blood with 50 pg/ml LPS up-regulated IL-6 mRNA levels 8000- to 50,000-fold in vitro. LPS infusion increased synthesis of gp130 mRNA 5.5-fold compared to baseline at 4 h (P < 0.05), while no significant change was observed in the placebo period (P = 0.001 between groups). LPS increased the percentage of gp130 positive neutrophils gp130 700% over baseline at 8 h (P < 0.01 versus baseline and placebo). IL-6 receptor levels were not significantly altered by low-grade endotoxemia. In conclusion, endotoxemia up-regulates gp130 expression in vivo and in vitro. Quantification of IL-6 mRNA expression in circulating leukocytes is unlikely a suitable marker for monitoring of endotoxemia.     

核黄素对STZ诱导的大鼠糖尿病肾病的治疗作用

目的:探讨核黄素对STZ诱导的大鼠糖尿病肾病的治疗作用及机制。方法:将雄性Sprague-Daw-ley大鼠随机分为3组,即正常对照组、糖尿病模型组、核黄素治疗组,采用腹腔注射链脲佐菌素法建立糖尿病大鼠模型,收集各组血、尿及肾组织,生化方法检测24h尿蛋白量、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)的活性及丙二醛(MDA)的含量,并计算肾脏脏器系数(KW/BW);Western blotting检测不同组别肾皮质TGF-β1、纤溶酶原活化抑制因子-1(PAI-1)蛋白质水平;光镜观察肾组织形态改变。结果:与糖尿病模型组大鼠比较,核黄素治疗组大鼠尿蛋白量显著降低(P0.01),肾组织及血清SOD、CAT活性升高(P0.01),肾组织MDA含量显著降低(P0.01),核黄素治疗组肾皮质TGF-β1及PAI-1蛋白表达明显低于糖尿病模型组。结论:核黄素对STZ诱导的糖尿病大鼠肾脏有一定的保护作用,其机制可能与其降低肾组织TGF-β1、PAI-1蛋白表达有关。     

厄洛替尼减轻STZ诱导的糖尿病肾病模型大鼠的肾损伤

目的:研究表皮生长因子受体(EGFR)抑制剂厄洛替尼(erlotinib)对糖尿病肾病大鼠肾脏的保护作用及机制。方法:采用大剂量(55 mg/kg)链脲佐菌素(STZ)腹腔注射诱导大鼠糖尿病肾病模型,以1周后血糖值16.7 mmol/L的大鼠为造模成功的标准。将糖尿病大鼠随机分为2组[STZ组和STZ+erlotinib(100 mg·kg~(-1)·d~(-1))组],并以正常大鼠为对照组(control组)。Erlotinib处理4周后,检测大鼠空腹血糖、血清肌酐和24 h尿蛋白含量的变化;HE染色和Masson染色观察肾脏组织病理学改变;Western blot检测各组肾脏组织中EGFR、p-EGFR、转化生长因子β1(TGFβ1)、Smad2/3、p-Smad2/3、Ⅳ型胶原蛋白(ColⅣ)和纤连蛋白(fibronectin)的蛋白水平;活性氧簇(ROS)和丙二醛(MDA)试剂盒分别检测各组肾脏组织中ROS和MDA水平。结果:与control组相比,STZ组血糖、24 h尿蛋白和血清肌酐水平均显著升高(P0.01),肾组织形态学出现异常变化;与STZ组相比,STZ+erlotinib组的血糖、24 h尿蛋白水平和血清肌酐水平显著降低(P0.05),肾小球结构恢复正常,肾小球系膜细胞增生程度明显减弱。厄洛替尼明显抑制了STZ大鼠肾组织中p-EGFR、TGFβ1、p-Smad2/3、ColⅣ和fibronectin蛋白水平,也明显抑制了STZ大鼠肾组织中ROS和MDA水平。结论:厄洛替尼可能通过抑制EGFR/TGFβ1-Smad2/3信号通路的激活来抑制糖尿病肾病肾组织的纤维化和氧化应激反应,从而减轻肾损伤。     

运动通过下调烟酰胺腺嘌呤二核苷酸磷酸氧化酶亚基改善糖尿病心肌病

目的:探讨链脲霉素诱导的糖尿病对烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶的影响,测定运动的干预效应。方法:SD大鼠糖尿病建模成功1周后,检测心室和心房肌中NADPH氧化酶亚基的表达以及心血管紧张素Ⅱ的表达,测定8周的运动能否有效影响NADPH亚基以及血管紧张素Ⅱ的表达。结果:糖尿病导致心室肌NADPH氧化酶亚基p67~(Phox)和gp91~(phox)表达增加,而8周运动能够抑制两种亚基表达的增加。糖尿病心房肌p67~(phox)增加显著,运动抑制其增加。糖尿病心血管紧张素Ⅱ水平显著增加,运动降低血管紧张素Ⅱ的增加。结论:运动降低糖尿病大鼠心肌p67~(phox)和gp91~(phox)表达的增加,这可能是改善心内基质的机制之一,因此运动治疗和预防糖尿病心肌病的一个有效机制可能是通过抑制心肌氧化应激和降低血管紧张素Ⅱ的表达。     

姜黄素类似物L6H4对2型糖尿病大鼠心肌的保护作用

 目的: 探讨姜黄素类似物L6H4对2型糖尿病心肌病大鼠的保护作用及机制。方法: 雄性SD大鼠40只,随机均分为正常对照(NC)组、高脂(HF)组、高脂治疗(FT)组、糖尿病(DM)组和糖尿病治疗(DT)组。采用高脂饮食加链脲佐菌素诱导2型糖尿病模型,用L6H4治疗8周。生化法测血糖及血脂水平,ELISA法测血清脂联素(APN)水平,放射免疫法测大鼠血清胰岛素水平,并计算胰岛素抵抗指数(HOMA-IR),Masson染色和电镜观察心肌形态改变,免疫组化测心肌脂联素受体1 (AdipoR1)及转化生长因子β1(TGF-β1)蛋白的表达。Western blot法检测大鼠心肌内AdipoR1蛋白表达量。结果: HF组及DM组大鼠血糖、血脂、胰岛素、HOMA-IR及TGF-β1蛋白水平较NC组均有升高,L6H4治疗后均下降;HF组及DM组大鼠血清APN水平及心肌AdipoR1较NC组均有下降,L6H4治疗后均升高。DM组和HF组大鼠心肌纤维化,线粒体肿胀,嵴紊乱,部分消失,经L6H4干预后,大鼠心肌的形态学损害明显减轻。结论: L6H4对2型糖尿病大鼠的心肌具有保护作用;血清APN浓度增加,心肌AdipoR1蛋白表达增强,及APN抑制TGF-β1的表达可能参与其中。     

The cytokine receptor gp130 and its soluble form are under hormonal control in human endometrium and decidua

The transmembrane protein gp130 plays a central role in cytokine action as a signal transducing receptor subunit common to all interleukin-6 type cytokines. Endometrial tissue obtained from women with a normal menstrual cycle and decidua obtained from women in the first or second trimester of pregnancy were assessed for gp130 by western blotting, immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) analysis. By immunoblotting, two forms of gp130 were detected: one-the soluble form-of approximately 100 kDa and a larger membrane-bound form of approximately 150 kDa. The latter became clearly visible in the mid to late secretory phase and was more pronounced in decidual tissue of second trimester compared to first trimester. Immunohistochemically, gp130 was located in glandular epithelial cells during the mid to late secretory phase, whereas staining in the proliferative phase was rather weak. In first and second trimester decidua, glandular cells were also positively stained. In addition, the invading trophoblast cells were gp130 positive. Soluble gp130 release was measured in the supernatants from primary endometrial and decidual cell cultures by ELISA and reached maximum values in cell cultures without addition of hormones. In cultured endometrial epithelial cells obtained during the proliferative phase of the cycle, the soluble gp130 release increased significantly under combined estradiol/progesterone supplementation which mimics the secretory phase conditions compared to estradiol supplementation alone. In cultured epithelial cells derived from decidual tissue of first trimester of pregnancy, similar effects of hormonal regulation were observed. Our results suggest that the balance between soluble gp130 and its membrane-bound form may play an important role in regulating cytokine action necessary for blastocyst implantation and for further interaction between the decidualized endometrium and the invading trophoblast.     

2型糖尿病大鼠骨骼肌Toll样受体4的表达及辛伐他汀的干预作用

目的 探讨2型糖尿病大鼠骨骼肌组织Toll样受体4（TLR4）的表达及辛伐他汀的干预作用.方法 以高脂高糖饲料联合小剂量链脲佐菌素喂养SD大鼠制备2型糖尿病大鼠模型（26只）,随机分为糖尿病组（n=13）和辛伐他汀干预组（n=13）,正常SD大鼠（n=10）作为对照组.辛伐他汀干预组给予辛伐他汀20 mg·kg^-1·d^-1灌胃,糖尿病组和对照组均给予等体积生理盐水灌胃.8周后检测各组大鼠血糖、血脂、肌酸激酶水平;光镜观察骨骼肌组织学改变;免疫组织化学检测骨骼肌TLR4蛋白的表达;RT-PCR法检测骨骼肌TLR4 mRNA的表达.结果 糖尿病组和辛伐他汀干预组空腹血糖较对照组明显升高[（12.04±2.04） mmol/L、（11.23±2.61） mmol/L比（5.92± 1.28） mmol/L,均P＜0.05],糖尿病组和辛伐他汀干预组两组之间空腹血糖水平差异无统计学意义.3组总胆固醇（TC）、三酰甘油（TG）、低密度脂蛋白胆固醇（LDL-C）水平糖尿病组＞辛伐他汀干预组＞对照组（均P＜0.05）;高密度脂蛋白胆固醇（HDL-C）水平对照组＞辛伐他汀干预组＞糖尿病组（均P＜0.05）.3组肌酸激酶之间差异无统计学意义.对照组大鼠骨骼肌肌膜完整、清晰,肌纤维排列紧密;糖尿病组大鼠部分肌纤维萎缩、变性、水肿,肌纤维断裂,肌丝走行紊乱,并可见炎性细胞浸润;辛伐他汀干预组大鼠病理改变较糖尿病组减轻.糖尿病组TLR4蛋白表达水平是对照组的1.54倍[0.318±0.037比0.206±0.024,P＜0.05],辛伐他汀干预组TLR4蛋白表达水平0.256±0.035,是糖尿病组的80.50％ （P＜ 0.05）.糖尿病组TLR4 mRNA水平是对照组的1.62倍[0.625±0.074比0.385±0.088,P＜0.05],辛伐他汀干预组TLR4 mRNA水平0.501±0.105,是糖尿病组的80.16％（P＜ 0.05）.结论 糖尿病性骨骼肌病变与TLR4高表达相关,辛伐他汀可能通过降低骨骼肌TLR4的表达从而减轻骨骼肌病变.     

A combination of interleukin-6 and its soluble receptor impairs sperm motility: implications in infertility associated with endometriosis

BACKGROUND: We previously reported that the level of interleukin (IL)-6 is increased in the peritoneal fluid of women with endometriosis. This study was undertaken to assess the effects of IL-6 and soluble IL-6 receptor (sIL-6R) on in vitro sperm motility. METHODS: Sperm (n = 20) were cultured with IL-6 or sIL-6R, or with a combination of both. After 24 h cultures, sperm motility was evaluated using a computer-assisted semen analysis system. Gene and protein expressions of IL-6, IL-6 receptor (IL-6R), and glycoprotein 130 (gp130) were examined in sperm by RT-PCR analysis and western blot analysis. RESULTS: Addition of IL-6 or sIL-6R individually to the culture media had no affect on sperm motion. However, adding a combination of IL-6 and sIL-6R dose-dependently reduced the percentage of motile and rapidly moving sperm. Adding anti-IL-6R antibody abolished these adverse effects. Sperm expressed the gp130 gene and protein, but not IL-6 or IL-6R. CONCLUSIONS: A combination of IL-6 and sIL-6R may be associated with gp130 expressed in the sperm and reduce sperm motility. IL-6 and sIL-6R may contribute to the pathogenesis of endometriosis-associated infertility.     

白血病抑制因子作为自身分泌生长因子在人脑髓母细胞瘤内的表达

对15例髓母细胞瘤手术标本／细胞系内白血病抑制因子（LIF）及其配体基因LIFR和PP130的表达以及LIF对髓母细胞生长的作用进行了研究。结果表明，15例被检样本中，14例有LIF表达和产生，90％以上表达LIFR，IL－6R和gP130中和LIF生物活性可明显抑制细胞生长（P＜0.001）。这提示：内源性LIF对髓母细胞起生长促进作用，阻断LIF生物活性或基因表达可能成为髓母细胞瘤的免疫或基因治疗途径。     

MicroRNA-146在糖尿病心肌病中的调控作用

目的:探讨微小RNA-146 (miR-146)在糖尿病心肌病(DCM)发病机制中的作用,观察miR-146及其下游靶基因表达水平的变化。方法:60只雄性C57BL/6小鼠随机分为实验(DCM)组和对照(control)组,每组30只,实验组采用低剂量(50 mg/kg链脲佐菌素(STZ)腹腔注射诱导建立糖尿病心肌病模型,对照组给予等量枸橼酸钠缓冲液腹腔注射,建模12周后取心脏做HE和Masson染色观察心脏病理改变,RT-qPCR检测miR-146 a和miR-146b及其下游靶基因白细胞介素-1受体相关激酶1(IRAK1)和TNF受体相关因子6(TRAF6)的mRNA表达,Western blot检测IRAK1和TRAF6的蛋白表达。结果:12周末HE染色显示,DCM组心肌肥大,结构紊乱;Masson染色显示,DCM组心肌内胶原纤维增多;RT-qPCR检测结果显示,DCM组中miR-146a及miR-146b较control组表达明显减少(P 0. 01),IRAK1的mRNA水平明显增高(P 0. 01),而TRAF6的mRNA水平下降(P 0. 01);Western blot检测结果显示DCM组的IRAK1蛋白表达增加,TRAF6的蛋白表达降低(P 0. 01)。结论:miR-146可能通过调节IRAK1介导的炎症反应参与糖尿病心肌损伤的发生发展。     

NF-E2相关因子2对糖尿病模型小鼠视网膜内细胞及血管的保护作用

目的 探讨NF-E2相关因子2（Nrf2）对糖尿病视网膜细胞及血管的保护作用。方法 8周龄雄性Nrf2^+/+（野生型）和Nrf2^-/- C57BL/6小鼠60只随机分为模型组和对照组,共4组,每组各15只。模型组小鼠腹腔注射链脲佐菌素（STZ,45mg/kg）,连续注射5 d;对照组小鼠注射同体积的枸橼酸缓冲液。模型组和对照组小鼠初次注射后每周测空腹血糖及体重,至第10周取视网膜。采用免疫印迹法检测视网膜内Nrf2激活的下游蛋白血红素加氧酶-1（HO-1）的表达情况;免疫荧光染色检测具有多种剪接形式的RNA结合蛋白（RBPMS）阳性的视网膜节细胞（RGCs）及胆碱乙酰转移酶（ChAT）阳性的无长突细胞（ACs）并计数;采用过碘酸-希夫和苏木素染色,观察视网膜内无细胞毛细血管并进行定量分析。 结果 STZ诱导1周后,野生型和Nrf2^-/-模型组小鼠血糖急剧升高,体重开始显著下降,随着周龄的增长体重无明显增加;对照组小鼠血糖值无明显升高,体重呈正常缓慢增长趋势。STZ诱导糖尿病10周后,RBPMS和ChAT染色发现,Nrf2^-/-糖尿病小鼠视网膜内RGCs和ACs数量显著降低（P<0.05）;过碘酸 希夫和苏木素染色显示,Nrf2^-/-糖尿病小鼠视网膜内出现无细胞毛细血管;免疫印迹法显示,野生型小鼠模型组中Nrf2激活的下游蛋白HO-1表达升高。 结论 Nrf2对糖尿病视网膜细胞及血管具有保护作用,其可能是通过诱导HO-1上调发挥作用。     

Beneficial effects of troglitazone on neutrophil dysfunction in multiple low-dose streptozotocin-induced diabetic mice

Patients with poorly controlled diabetes are at high risk of acquiring bacterial infections. However, conflicting results have been reported on neutrophil function in diabetes. We periodically evaluated neutrophil dysfunction in multiple low-dose streptozotocin (STZ)-induced diabetic mice, and then evaluated the effects of troglitazone and other thiazolidinediones (TZDs) on the decline of neutrophil function. Zymosan was injected intraperitoneally and neutrophil infiltration and phagocytosis were evaluated. While phagocytosis of zymosan by peritoneal neutrophils was consistently reduced in diabetic mice, neutrophil infiltration was decreased on day 30, but increased on day 40 after STZ injection. The in vitro chemotactic and phagocytic activities of blood neutrophils in mice that did not receive zymosan were consistently reduced in diabetic mice. Phorbol myristate acetate (PMA)-stimulated superoxide production by zymosan-induced peritoneal neutrophils and the levels of zymosan-induced tumour necrosis factor (TNF)-alpha and interleukin (IL)-1beta in peritoneal exudate fluids were also reduced in the diabetic mice. Treatment of the diabetic mice with troglitazone beginning 2 weeks after STZ injection did not improve hyperglycaemia but did prevent the decline of zymosan-induced neutrophil infiltration on day 30, and additionally promoted the increased infiltration on day 40. Troglitazone also promoted the chemotactic activity of blood neutrophils isolated from normal mice in vitro. Rosiglitazone but not pioglitazone induced a similar effect. Neutrophil phagocytosis was not enhanced by troglitazone either in vivo or in vitro. Taken together, neutrophil function is impaired by STZ-induced diabetes, but inflammatory infiltration does not always vary with the chemotactic disability or cytokine levels. Furthermore, troglitazone and rosiglitazone were suggested to improve at least neutrophil chemotactic activity in these animals.     

转录因子FoxO1、FoxO3a在KKAy胰岛素抵抗糖尿病小鼠肌肉和肝组织中的表达

目的研究FoxO1和FoxO3 a在胰岛素抵抗糖尿病动物模型KKAy小鼠肌肉和肝中的表达,了解它们在胰岛素抵抗机制中所起的作用。方法对照组为16周龄C57BL小鼠7只,实验组为KKAy糖尿病小鼠7只;小鼠4周龄开始普通饲料喂养至12周龄,随后高脂饲料喂养4周,连续2次随机血糖≥16.7 mmol/L诊断为糖尿病。取股四头肌和肝加上组织裂解液B radford法测定蛋白浓度,W estern B lot方法检测肌肉和肝组织中FoxO1和FoxO3 a蛋白的表达。结果KKAy糖尿病小鼠FoxO1肝和肌肉中表达显著高于对照组小鼠;FoxO3 a肝表达对照组和糖尿病组之间没有差别,肌肉组织表达在糖尿病组显著高于对照组。结论FoxO1和FoxO3 a在胰岛素抵抗和糖尿病状态下表达显著增加,可能在胰岛素抵抗和糖尿病的发病机制中起重要作用。