Whether cultured bovine trabecular meshwork cells and trabecular tissue ex vivo express insulin like growth factor I (IGF Ⅰ) messenger RNA (mRNA) and protein was investigated. Total RNA of cultured bovine trabecul...Whether cultured bovine trabecular meshwork cells and trabecular tissue ex vivo express insulin like growth factor I (IGF Ⅰ) messenger RNA (mRNA) and protein was investigated. Total RNA of cultured bovine trabecular meshwork cells as well as trabecular meshwork tissue freshly excised from bovine eyes was extracted, and reverse transcriptase polymerase chain reaction (RT PCR) was used to detect IGF Ⅰ mRNA. RT PCR product was verified by sequencing. Immunohistochemical stain was used to detect IGF Ⅰ protein. The results showed that a single PCR amplified product was obtained, and the sequence was homologous to the known sequence.. IGF Ⅰ immunostain was positive in the cytoplasm of trabecular meshwork cells. It was concluded that trabecular meshwork cells produce IGF Ⅰ and contribute to the presence of IGF Ⅰ in trabecular meshwork microenvironment as well as aqueous humor. Trabecular meshwork cells were affected by IGF Ⅰ not only through paracrine, but also autocrine action. Whether abnormal down regulations in IGF Ⅰ production may contribute to the pathogenesis of primary open angle glaucoma and the possibility of promoting the autocrine action of IGF Ⅰ by trabecular meshwork cells to treat the diesease is worth further investigation.展开更多
Previous studies have shown that sericin extracted from silk cocoon significantly reduces blood glucose levels and protects the nervous system against diabetes mellitus. In this study, a rat type 2 diabetes mellitus m...Previous studies have shown that sericin extracted from silk cocoon significantly reduces blood glucose levels and protects the nervous system against diabetes mellitus. In this study, a rat type 2 diabetes mellitus model was established by intraperitoneal injection of 25 mg/kg streptozotocin for 3 successive days, following which the rats were treated with sericin for 35 days. After treatment, the blood glucose levels of the diabetic rats decreased significantly, the growth hormone level in serum and its expression in the hippocampus decreased significantly, while the insulin-like growth factor-1 level in serum and insulin-like growth factor-1 and growth hormone receptor expression in the hippocampus increased significantly. The experimental findings indicate that sericin improves disorders of the growth hormone/insulin-like growth factor 1 axis to alleviate hippocampal damage in diabetic rats.展开更多
AIM： To investigate the ability of a genetically altered embryonic stem （ES） cell line to generate insulin-producing cells in vitro following transfer of the Nkx2.2 gene.METHODS： Hamster Nkx2.2 genes were transfer...AIM： To investigate the ability of a genetically altered embryonic stem （ES） cell line to generate insulin-producing cells in vitro following transfer of the Nkx2.2 gene.METHODS： Hamster Nkx2.2 genes were transferred into mouse ES cells. Parental and Nkx2.2-transfected ES cells were initiated toward differentiation in embryoid body （EB） culture for 5 d and the resulting EBs were transferred to an attached culture system. Dithizone （DTZ）, a zincchelating agent known to selectively stain pancreatic beta cells, was used to detect insulin-producing cells.The outgrowths were incubated in DTZ solution （final concentration, 100μg/mL） for 15 rain before being examined microscopically. Gene expression of the endocrine pancreatic markers was also analyzed by RT-PCR. In addition, insulin production was determined immunohistochemically and its secretion was examined using an ELISA.RESULTS： DTZ-stained cellular clusters appeared after approximately 14 d in the culture of Nkx2.2-transfected ES cells （Nkx-ES cells）, which was as much as 2 wk earlier, than those in the culture of parental ES cells （wt-ES）. The frequency of DTZ-positive cells among total cultured cells on day 28 accounted for approximately 1.0% and 0.1% of the Nkx-ES- and wt-ES-derived EB outgrowths, respectively. The DTZ-positive cellular clusters were found to be immunoreactive to insulin, while the gene expressions of pancreatic-duodenal homeobox 1 （PDX1）, proinsulin 1 and proinsulin 2 were observed in the cultures that contained DTZ-positive cellular clusters.Insulin secretion was also confirmed by ELISA, whereas glucose-dependent secretion was not demonstrated.CONCLUSION： Nkx2.2-transfected ES cells showed an ability to differentiate into insulin-producing cells.展开更多
目的探讨沉默转录因子7类似物2(TCF7L2)对胰岛素抵抗(IR)Hep G2细胞胰岛素降解酶(IDE)表达的调控作用及可能机制。方法将Hep G2细胞分为空白组、TCF7L2干扰组、空载体组、IR组、IR+TCF7L2干扰组、IR+空载体组。采用高浓度胰岛素(5×...目的探讨沉默转录因子7类似物2(TCF7L2)对胰岛素抵抗(IR)Hep G2细胞胰岛素降解酶(IDE)表达的调控作用及可能机制。方法将Hep G2细胞分为空白组、TCF7L2干扰组、空载体组、IR组、IR+TCF7L2干扰组、IR+空载体组。采用高浓度胰岛素(5×10-6mol/L)持续作用24h诱导IR模型(IR-Hep G2细胞)生成。以人TCF7L2 m RNA编码序列为干扰靶点构建TCF7L2特异性小干扰RNA慢病毒载体(LV-TCF7L2-si RNA)转染空白组及IR组细胞,空载体病毒转染空载体组及IR+空载体组细胞。q RT-PCR法检测各组细胞TCF7L2及IDE m RNA的表达,Western blotting检测各组细胞TCF7L2、IDE、胰岛素刺激后蛋白激酶B(AKT)、磷酸化蛋白激酶B(p-AKT)蛋白表达的变化,流式细胞术检测各组2-脱氧-D-葡萄糖(2-NBDG)荧光葡萄糖摄取率。结果与空白组比较,IR组细胞葡萄糖消耗量及2-NBDG摄取率均明显降低(P<0.01),证明IR细胞模型建立成功。q RT-PCR及Western blotting结果显示,IR组TCF7L2及IDE m RNA种蛋白表达水平均明显低于空白组(P<0.05),TCF7L2干扰组TCF7L2、IDE m RNA和蛋白表达水平较空白组、空载体组明显下降,IR+TCF7L2干扰组TCF7L2、IDE m RNA和蛋白表达水平较IR组、IR+空载体组均明显下降(P<0.05)。生理剂量胰岛素刺激后,IR组、IR+TCF7L2干扰组p-AKT蛋白水平较空白组明显下降(P<0.01),各组总AKT水平差异无统计学意义。TCF7L2干扰组2-NBDG荧光葡萄糖摄取率较空白组和空载体组明显下降,IR+TCF7L2干扰组2-NBDG荧光葡萄糖摄取率较IR组、IR+空载体组明显下降(P<0.01)。结论 TCF7L2联合IDE致肝细胞IR,其机制可能与减少胰岛素信号通路关键酶p-AKT蛋白的表达有关。展开更多
基金This projectwas supported by a grant from National Nat-ural Sciences Founction of China (No.38970 75 8)
文摘Whether cultured bovine trabecular meshwork cells and trabecular tissue ex vivo express insulin like growth factor I (IGF Ⅰ) messenger RNA (mRNA) and protein was investigated. Total RNA of cultured bovine trabecular meshwork cells as well as trabecular meshwork tissue freshly excised from bovine eyes was extracted, and reverse transcriptase polymerase chain reaction (RT PCR) was used to detect IGF Ⅰ mRNA. RT PCR product was verified by sequencing. Immunohistochemical stain was used to detect IGF Ⅰ protein. The results showed that a single PCR amplified product was obtained, and the sequence was homologous to the known sequence.. IGF Ⅰ immunostain was positive in the cytoplasm of trabecular meshwork cells. It was concluded that trabecular meshwork cells produce IGF Ⅰ and contribute to the presence of IGF Ⅰ in trabecular meshwork microenvironment as well as aqueous humor. Trabecular meshwork cells were affected by IGF Ⅰ not only through paracrine, but also autocrine action. Whether abnormal down regulations in IGF Ⅰ production may contribute to the pathogenesis of primary open angle glaucoma and the possibility of promoting the autocrine action of IGF Ⅰ by trabecular meshwork cells to treat the diesease is worth further investigation.
基金sponsored by the Natural Science Foundation of Hebei Province,H2012406018,H2013406096a grant from Hebei Province Department of Education,No.2006301
文摘Previous studies have shown that sericin extracted from silk cocoon significantly reduces blood glucose levels and protects the nervous system against diabetes mellitus. In this study, a rat type 2 diabetes mellitus model was established by intraperitoneal injection of 25 mg/kg streptozotocin for 3 successive days, following which the rats were treated with sericin for 35 days. After treatment, the blood glucose levels of the diabetic rats decreased significantly, the growth hormone level in serum and its expression in the hippocampus decreased significantly, while the insulin-like growth factor-1 level in serum and insulin-like growth factor-1 and growth hormone receptor expression in the hippocampus increased significantly. The experimental findings indicate that sericin improves disorders of the growth hormone/insulin-like growth factor 1 axis to alleviate hippocampal damage in diabetic rats.
文摘AIM： To investigate the ability of a genetically altered embryonic stem （ES） cell line to generate insulin-producing cells in vitro following transfer of the Nkx2.2 gene.METHODS： Hamster Nkx2.2 genes were transferred into mouse ES cells. Parental and Nkx2.2-transfected ES cells were initiated toward differentiation in embryoid body （EB） culture for 5 d and the resulting EBs were transferred to an attached culture system. Dithizone （DTZ）, a zincchelating agent known to selectively stain pancreatic beta cells, was used to detect insulin-producing cells.The outgrowths were incubated in DTZ solution （final concentration, 100μg/mL） for 15 rain before being examined microscopically. Gene expression of the endocrine pancreatic markers was also analyzed by RT-PCR. In addition, insulin production was determined immunohistochemically and its secretion was examined using an ELISA.RESULTS： DTZ-stained cellular clusters appeared after approximately 14 d in the culture of Nkx2.2-transfected ES cells （Nkx-ES cells）, which was as much as 2 wk earlier, than those in the culture of parental ES cells （wt-ES）. The frequency of DTZ-positive cells among total cultured cells on day 28 accounted for approximately 1.0% and 0.1% of the Nkx-ES- and wt-ES-derived EB outgrowths, respectively. The DTZ-positive cellular clusters were found to be immunoreactive to insulin, while the gene expressions of pancreatic-duodenal homeobox 1 （PDX1）, proinsulin 1 and proinsulin 2 were observed in the cultures that contained DTZ-positive cellular clusters.Insulin secretion was also confirmed by ELISA, whereas glucose-dependent secretion was not demonstrated.CONCLUSION： Nkx2.2-transfected ES cells showed an ability to differentiate into insulin-producing cells.
文摘目的 探讨长链非编码RNA(long non-coding RNA,LncRNA)核富集转录本1(nuclear enriched abundant transcript 1,NEAT1)通过调节微小核糖核酸(micro RNAs,miR)-125b-5p/胰岛素样生长因子结合蛋白5(insulinlike growth factor binding protein 5,IGFBP5)轴对血管瘤内皮细胞增殖、凋亡和迁移的影响。方法 实时荧光定量PCR(quantitative real-time PCR,qRT-PCR)、蛋白免疫印迹(Western blot)分别检测血管瘤组织(2016年3月~2019年3月收集,n=18)、瘤旁组织样本(2016年3月~2019年3月收集,n=18)以及人脐静脉内皮细胞HUVES,人血管瘤内皮细胞HemECs,HDEC中NEAT1,miR-125b-5p及IGFBP5蛋白表达。构建沉默NEAT1,同时沉默NEAT1和miR-125b-5p的HemECs细胞系,通过细胞活力检测试剂盒(cell counting kit-8,CCK-8)、台盼蓝染色、流式细胞术、划痕愈合实验、Western blot分别观察NEAT1和miR-125b-5p对HemECs细胞增殖、凋亡、迁移及IGFBP5,增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)、B细胞淋巴瘤/白血病-2(B cell lymphoma/lewkmia-2,Bcl-2)和基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)蛋白表达的影响;双荧光素酶报告基因实验检测NEAT1与miR-125b-5p,mi R-125b-5p与IGFBP5的关系。结果 与瘤旁组织比较,血管瘤组织中NEAT1(2.87±0.22 vs 1.00±0.00),IGFBP5蛋白(1.45±0.14 vs 0.27±0.02)表达水平升高,miR-125b-5p(0.24±0.02 vs 1.00±0.00)表达水平降低,差异具有统计学意义(t=35.400~161.220,均P <0.05);与HUVES细胞比较,HemECs,HDEC细胞中NEAT1(2.76±0.24,1.78±0.13 vs 1.00±0.00),IGFBP5蛋白(1.31±0.15,0.78±0.06 vs 0.24±0.02)表达升高,miR-125b-5p表达(0.19±0.02,0.45±0.04 vs 1.00±0.00)降低,差异具有统计学意义(t=17.320~99.204,14.697~33.680,均P<0.05),且HemECs细胞中NEAT1和IGFBP5蛋白表达量最高,miR-125b-5p表达量最低,因此,选取HemECs细胞为研究对象;与si-NC组比较,si-NEAT1组NEAT1(0.32±0.02 vs 1.01±0.12)表达、A值(0.45±0.04 vs 1.13±0.11)、细胞生长率(32.28%±2.79%vs 99.41%±0.22%)、划痕愈合率(20.33%±1.23%vs 49.24%±2.43%)及IGFBP5(0.41±0.04 vs 1.31±0.20),PCNA(0.36±0.04 vs 1.27±0.14),Bcl-2(0.48±0.04 vs 1.39±0.16)和MMP-9(0.21±0.02 vs 1.09±0.10)蛋白表达降低,mi R-125b-5p(1.87±0.15 vs 1.02±0.10)表达、细胞凋亡率(45.58%±3.34%vs 12.36%±1.07%)升高,差异具有统计学意义(t=10.809~58.755,均P <0.05);下调miR-125b-5p减弱了沉默NEAT1对HemECs细胞增殖、迁移的抑制及对细胞凋亡的促进作用(t=9.218~15.010,均P <0.05);NEAT1与miR-125b-5p,miR-125b-5p与IGFBP5存在靶向调控关系。结论 沉默NEAT1通过上调miR-125b-5p来抑制IGFBP5表达,从而抑制HemECs细胞增殖、迁移,并促进细胞凋亡。
文摘目的探讨沉默转录因子7类似物2(TCF7L2)对胰岛素抵抗(IR)Hep G2细胞胰岛素降解酶(IDE)表达的调控作用及可能机制。方法将Hep G2细胞分为空白组、TCF7L2干扰组、空载体组、IR组、IR+TCF7L2干扰组、IR+空载体组。采用高浓度胰岛素(5×10-6mol/L)持续作用24h诱导IR模型(IR-Hep G2细胞)生成。以人TCF7L2 m RNA编码序列为干扰靶点构建TCF7L2特异性小干扰RNA慢病毒载体(LV-TCF7L2-si RNA)转染空白组及IR组细胞,空载体病毒转染空载体组及IR+空载体组细胞。q RT-PCR法检测各组细胞TCF7L2及IDE m RNA的表达,Western blotting检测各组细胞TCF7L2、IDE、胰岛素刺激后蛋白激酶B(AKT)、磷酸化蛋白激酶B(p-AKT)蛋白表达的变化,流式细胞术检测各组2-脱氧-D-葡萄糖(2-NBDG)荧光葡萄糖摄取率。结果与空白组比较,IR组细胞葡萄糖消耗量及2-NBDG摄取率均明显降低(P<0.01),证明IR细胞模型建立成功。q RT-PCR及Western blotting结果显示,IR组TCF7L2及IDE m RNA种蛋白表达水平均明显低于空白组(P<0.05),TCF7L2干扰组TCF7L2、IDE m RNA和蛋白表达水平较空白组、空载体组明显下降,IR+TCF7L2干扰组TCF7L2、IDE m RNA和蛋白表达水平较IR组、IR+空载体组均明显下降(P<0.05)。生理剂量胰岛素刺激后,IR组、IR+TCF7L2干扰组p-AKT蛋白水平较空白组明显下降(P<0.01),各组总AKT水平差异无统计学意义。TCF7L2干扰组2-NBDG荧光葡萄糖摄取率较空白组和空载体组明显下降,IR+TCF7L2干扰组2-NBDG荧光葡萄糖摄取率较IR组、IR+空载体组明显下降(P<0.01)。结论 TCF7L2联合IDE致肝细胞IR,其机制可能与减少胰岛素信号通路关键酶p-AKT蛋白的表达有关。
