目的基于RAS同源基因家族成员相关激酶(ROCK)/烟酰胺腺嘌呤二核苷酸磷酸氧化酶(NOX)4信号通路探究刺芒柄花素对2型糖尿病大鼠内质网应激损伤及肾功能的影响。方法SPF级健康8周龄雄性C57BL/6大鼠60只,随机分为5组,各12只,健康组、模型组...目的基于RAS同源基因家族成员相关激酶(ROCK)/烟酰胺腺嘌呤二核苷酸磷酸氧化酶(NOX)4信号通路探究刺芒柄花素对2型糖尿病大鼠内质网应激损伤及肾功能的影响。方法SPF级健康8周龄雄性C57BL/6大鼠60只,随机分为5组,各12只,健康组、模型组、刺芒柄花素低、中、高组,除健康组外均建立2型糖尿病大鼠模型,刺芒柄花素低组、刺芒柄花素中组、刺芒柄花素高组分别给予20、40、100 mg/kg刺芒柄花素灌胃,其余组别灌胃等体积生理盐水。采用自动生化分析仪测定肾功能指标。苏木素-伊红(HE)染色与Masson染色观察大鼠肾组织病形态。TUNEL检测肾小管上皮细胞凋亡。免疫组化检测RAS同源基因家族成员(Rho)A、NOX4、ROCK阳性表达。Western印迹检测内质网应激相关蛋白表达。结果HE染色结果显示:健康组肾脏组织结构正常;模型组肾小球有一定程度萎缩,组织结构排列不均匀,并且有肿胀、脱落现象、还存在空泡样变性、鲍曼囊腔扩,而经过刺芒柄花素干预后,上述情况有所改善,且呈现出明显的剂量依赖性。Masson染色结果显示:健康组肾组织正常;模型组肾小球、肾小管基底膜增厚,产生空泡样病变,肾间质胶原纤维沉积明显;在经过刺芒柄花素干预后上述状况明显改善,且呈现出明显的剂量依赖性。健康组24 h MAU、SCr、BUN、细胞凋亡率、RhoA、NOX4、ROCL、eIF2α、GRP78水平显著低于模型组(P<0.05)。模型组24 h MAU、SCr、BUN、细胞凋亡率、RhoA、NOX4、ROCL、eIF2α、GRP78水平显著高于刺芒柄花素低组(P<0.05)。刺芒柄花素低组24 h MAU、SCr、BUN、细胞凋亡率、RhoA、NOX4、ROCL、eIF2α、GRP78水平显著高于刺芒柄花素中组(P<0.05)。刺芒柄花素中组24 h MAU、SCr、BUN、细胞凋亡率、RhoA、NOX4、ROCL、eIF2α、GRP78水平显著高于刺芒柄花素高组(P<0.05)。结论刺芒柄花素可能是通过调控Rho/ROCK/NOX4信号通路抑制了2型糖尿病大鼠内质网应激,改善肾功能,对肾脏起保护作用。展开更多
Reactive oxygen species （ROS） attack guanine bases in DNA easily and form 8-hydroxydeoxyguanosine （8-OHdG）, which can bind to thymidine rather than cytosine, based on which, the level of 8-OHdG is gen- erally rega...Reactive oxygen species （ROS） attack guanine bases in DNA easily and form 8-hydroxydeoxyguanosine （8-OHdG）, which can bind to thymidine rather than cytosine, based on which, the level of 8-OHdG is gen- erally regarded as a biomarker of mutagenesis conse- quent to oxidative stress. For example, higher levels of 8-OHdG are noted in Helicobacter pylori-associated chronic atrophic gastritis as well as gastric cancer. However, we have found that exogenous 8-OHdG can paradoxically reduce ROS production, attenuate the nuclear factor-KB signaling pathway, and ameliorate the expression of proinflammatory mediators such as interleukin （IL）-I, IL-6, cyclo-oxygenase-2, and induc- ible nitric oxide synthase in addition to expression of nicotinamide adenine dinucleotide phosphate oxidase （NOX）-I, NOX organizer-1 and NOX activator-1 in vari- ous conditions of inflammation-based gastrointestinal （GI） diseases including gastritis, inflammatory bowel disease, pancreatitis, and even colitis-associated carci- nogenesis. Our recent finding that exogenous 8-OHdG was very effective in either inflammation-based or oxidative-stress-associated diseases of stress-related mucosal damage has inspired the hope that synthetic 8-OHdG can be a potential candidate for the treatment of inflammation-based GI diseases, as well as the pre- vention of inflammation-associated GI cancer. In this editorial review, the novel fact that exogenous 8-OHdG can be a functional molecule regulating oxidative- stress-induced gastritis through either antagonizing Rac-guanosine triphosphate binding or blocking the signals responsible for gastric inflammatory cascade is introduced.展开更多
Objective： Chronic lymphocytic leukemia （CLL） and mantle cell lymphoma （MCL） cells over-express a guanine exchange factor （GEF）, Rasgrf-1. This GEF increases active Ras as it catalyzes the removal of GDP from R...Objective： Chronic lymphocytic leukemia （CLL） and mantle cell lymphoma （MCL） cells over-express a guanine exchange factor （GEF）, Rasgrf-1. This GEF increases active Ras as it catalyzes the removal of GDP from Ras so that GTP can bind and activate Ras. This study aims to study the mechanism of action of Rasgrf-1 in B-cell malignancies. Methods： N-terminus truncated Rasgrf-1 variants have a higher GEF activity as compared to the full-length transcript therefore a MCL cell line with stable over-expression of truncated Rasgrf-1 was established. The B-cell receptor （BCR） and chemokine signaling pathways were compared in the Rasgrf-I over-expressing and a control transfected cell line. Results： Cells over-expressing truncated form of Rasgrf-1 have a higher proliferative rate as compared to control transfected cells. BCR was activated by lower concentrations of anti-IgM antibody in Rasgrf-1 over-expressing cells as compared to control cells indicating that these cells are more sensitive to BCR signaling. BCR signaling also phosphorylates Rasgrf-1 that further increases its GEF function and amplifies BCR signaling. This activation of Rasgrf-1 in over-expressing cells resulted in a higher expression of phospho-ERK, AKT, BTK and PKC-alpha as compared to control cells. Besides BCR, Rasgrf-1 over-expressing cells were also more sensitive to microenvironment stimuli as determined by resistance to apoptosis, chemotaxis and ERK pathway activation. Conclusions： This GEF protein sensitizes B-cells to BCR and chemokine mediated signaling and also upregulates a number of other signaling pathways which promotes growth and survival of these cells.展开更多
文摘目的基于RAS同源基因家族成员相关激酶(ROCK)/烟酰胺腺嘌呤二核苷酸磷酸氧化酶(NOX)4信号通路探究刺芒柄花素对2型糖尿病大鼠内质网应激损伤及肾功能的影响。方法SPF级健康8周龄雄性C57BL/6大鼠60只,随机分为5组,各12只,健康组、模型组、刺芒柄花素低、中、高组,除健康组外均建立2型糖尿病大鼠模型,刺芒柄花素低组、刺芒柄花素中组、刺芒柄花素高组分别给予20、40、100 mg/kg刺芒柄花素灌胃,其余组别灌胃等体积生理盐水。采用自动生化分析仪测定肾功能指标。苏木素-伊红(HE)染色与Masson染色观察大鼠肾组织病形态。TUNEL检测肾小管上皮细胞凋亡。免疫组化检测RAS同源基因家族成员(Rho)A、NOX4、ROCK阳性表达。Western印迹检测内质网应激相关蛋白表达。结果HE染色结果显示:健康组肾脏组织结构正常;模型组肾小球有一定程度萎缩,组织结构排列不均匀,并且有肿胀、脱落现象、还存在空泡样变性、鲍曼囊腔扩,而经过刺芒柄花素干预后,上述情况有所改善,且呈现出明显的剂量依赖性。Masson染色结果显示:健康组肾组织正常;模型组肾小球、肾小管基底膜增厚,产生空泡样病变,肾间质胶原纤维沉积明显;在经过刺芒柄花素干预后上述状况明显改善,且呈现出明显的剂量依赖性。健康组24 h MAU、SCr、BUN、细胞凋亡率、RhoA、NOX4、ROCL、eIF2α、GRP78水平显著低于模型组(P<0.05)。模型组24 h MAU、SCr、BUN、细胞凋亡率、RhoA、NOX4、ROCL、eIF2α、GRP78水平显著高于刺芒柄花素低组(P<0.05)。刺芒柄花素低组24 h MAU、SCr、BUN、细胞凋亡率、RhoA、NOX4、ROCL、eIF2α、GRP78水平显著高于刺芒柄花素中组(P<0.05)。刺芒柄花素中组24 h MAU、SCr、BUN、细胞凋亡率、RhoA、NOX4、ROCL、eIF2α、GRP78水平显著高于刺芒柄花素高组(P<0.05)。结论刺芒柄花素可能是通过调控Rho/ROCK/NOX4信号通路抑制了2型糖尿病大鼠内质网应激,改善肾功能,对肾脏起保护作用。
基金Supported by A grant from the Ministry of Education and Science Technology,South Korea,No.2010-0002052
文摘Reactive oxygen species （ROS） attack guanine bases in DNA easily and form 8-hydroxydeoxyguanosine （8-OHdG）, which can bind to thymidine rather than cytosine, based on which, the level of 8-OHdG is gen- erally regarded as a biomarker of mutagenesis conse- quent to oxidative stress. For example, higher levels of 8-OHdG are noted in Helicobacter pylori-associated chronic atrophic gastritis as well as gastric cancer. However, we have found that exogenous 8-OHdG can paradoxically reduce ROS production, attenuate the nuclear factor-KB signaling pathway, and ameliorate the expression of proinflammatory mediators such as interleukin （IL）-I, IL-6, cyclo-oxygenase-2, and induc- ible nitric oxide synthase in addition to expression of nicotinamide adenine dinucleotide phosphate oxidase （NOX）-I, NOX organizer-1 and NOX activator-1 in vari- ous conditions of inflammation-based gastrointestinal （GI） diseases including gastritis, inflammatory bowel disease, pancreatitis, and even colitis-associated carci- nogenesis. Our recent finding that exogenous 8-OHdG was very effective in either inflammation-based or oxidative-stress-associated diseases of stress-related mucosal damage has inspired the hope that synthetic 8-OHdG can be a potential candidate for the treatment of inflammation-based GI diseases, as well as the pre- vention of inflammation-associated GI cancer. In this editorial review, the novel fact that exogenous 8-OHdG can be a functional molecule regulating oxidative- stress-induced gastritis through either antagonizing Rac-guanosine triphosphate binding or blocking the signals responsible for gastric inflammatory cascade is introduced.
文摘Objective： Chronic lymphocytic leukemia （CLL） and mantle cell lymphoma （MCL） cells over-express a guanine exchange factor （GEF）, Rasgrf-1. This GEF increases active Ras as it catalyzes the removal of GDP from Ras so that GTP can bind and activate Ras. This study aims to study the mechanism of action of Rasgrf-1 in B-cell malignancies. Methods： N-terminus truncated Rasgrf-1 variants have a higher GEF activity as compared to the full-length transcript therefore a MCL cell line with stable over-expression of truncated Rasgrf-1 was established. The B-cell receptor （BCR） and chemokine signaling pathways were compared in the Rasgrf-I over-expressing and a control transfected cell line. Results： Cells over-expressing truncated form of Rasgrf-1 have a higher proliferative rate as compared to control transfected cells. BCR was activated by lower concentrations of anti-IgM antibody in Rasgrf-1 over-expressing cells as compared to control cells indicating that these cells are more sensitive to BCR signaling. BCR signaling also phosphorylates Rasgrf-1 that further increases its GEF function and amplifies BCR signaling. This activation of Rasgrf-1 in over-expressing cells resulted in a higher expression of phospho-ERK, AKT, BTK and PKC-alpha as compared to control cells. Besides BCR, Rasgrf-1 over-expressing cells were also more sensitive to microenvironment stimuli as determined by resistance to apoptosis, chemotaxis and ERK pathway activation. Conclusions： This GEF protein sensitizes B-cells to BCR and chemokine mediated signaling and also upregulates a number of other signaling pathways which promotes growth and survival of these cells.
