Much research has focused on the PI3-kinase and PTEN signaling pathway with the aim to stimulate repair of the injured central nervous system.Axons in the central nervous system fail to regenerate,meaning that injurie...Much research has focused on the PI3-kinase and PTEN signaling pathway with the aim to stimulate repair of the injured central nervous system.Axons in the central nervous system fail to regenerate,meaning that injuries or diseases that cause loss of axonal connectivity have life-changing consequences.In 2008,genetic deletion of PTEN was identified as a means of stimulating robust regeneration in the optic nerve.PTEN is a phosphatase that opposes the actions of PI3-kinase,a family of enzymes that function to generate the membrane phospholipid PIP_(3) from PIP_(2)(phosphatidylinositol(3,4,5)-trisphosphate from phosphatidylinositol(4,5)-bisphosphate).Deletion of PTEN therefore allows elevated signaling downstream of PI3-kinase,and was initially demonstrated to promote axon regeneration by signaling through mTOR.More recently,additional mechanisms have been identified that contribute to the neuron-intrinsic control of regenerative ability.This review describes neuronal signaling pathways downstream of PI3-kinase and PIP3,and considers them in relation to both developmental and regenerative axon growth.We briefly discuss the key neuron-intrinsic mechanisms that govern regenerative ability,and describe how these are affected by signaling through PI3-kinase.We highlight the recent finding of a developmental decline in the generation of PIP_(3) as a key reason for regenerative failure,and summarize the studies that target an increase in signaling downstream of PI3-kinase to facilitate regeneration in the adult central nervous system.Finally,we discuss obstacles that remain to be overcome in order to generate a robust strategy for repairing the injured central nervous system through manipulation of PI3-kinase signaling.展开更多
Chen et al demonstrated that regulator of G protein signaling(RGS)4 promotes gastric cancer(GC)progression by activating the focal adhesion kinase/phospha-tidyl-inositol-3-kinase/protein kinase B pathway and inducing ...Chen et al demonstrated that regulator of G protein signaling(RGS)4 promotes gastric cancer(GC)progression by activating the focal adhesion kinase/phospha-tidyl-inositol-3-kinase/protein kinase B pathway and inducing epithelial-mesen-chymal transition.Although their multilevel approach integrating clinical data,functional assays,and xenograft models demonstrated a key role for RGS4 in GC pathogenesis,several limitations should be considered.The mechanism of the RGS4-focal adhesion kinase interaction remains unclear,specifically whether it involves direct binding or intermediaries.The clinical analysis of 90 patients lacks stratification by GC subtypes or immune features,potentially limiting generaliz-ability.Furthermore,fully validating RGS4’s oncogenic role requires additional studies,including functional assays in chemotherapy-resistant and metastatic cell lines,metastasis models including orthotopic implantation and tail vein injection,and comparison with other RGS family members.Addressing these via targeted mechanistic studies and expanded clinical validation could strengthen RGS4’s po-tential as a therapeutic target in GC.展开更多
目的:观察基于补肾健脾法拟定的中药汤剂补肾健脾活血方对多囊卵巢综合征伴胰岛素抵抗(PCOS-IR)模型大鼠的干预作用,并从磷脂酰肌醇3-激酶/蛋白激酶B/核因子κB(PI3K/Akt/NF-κB)信号通路探讨其作用机制。方法:将30只雌性SD大鼠随机分...目的:观察基于补肾健脾法拟定的中药汤剂补肾健脾活血方对多囊卵巢综合征伴胰岛素抵抗(PCOS-IR)模型大鼠的干预作用,并从磷脂酰肌醇3-激酶/蛋白激酶B/核因子κB(PI3K/Akt/NF-κB)信号通路探讨其作用机制。方法:将30只雌性SD大鼠随机分为正常组6只和造模组24只,造模组采用高脂饮食联合来曲唑灌胃法构建PCOS-IR模型。造模组所有大鼠均造模成功,将造模成功的24只大鼠随机分为模型组、阳性药物组(二甲双胍,每日给药量0.195 g/kg)和补肾健脾活血方低剂量组(每日给药量14.3 g/kg)、高剂量组(每日给药量28.6 g/kg),每组6只。各治疗组大鼠每日灌胃给予相应药物,模型组与正常组大鼠每日灌胃给予等量生理盐水,均每日1次,连续14 d。末次给药结束后当天下午4时起各组大鼠禁食不禁水,第2日上午9时开始进行取材和指标检测。尾尖取血,使用血糖仪检测空腹血糖(FBG);眼眶静脉取血,采用酶联免疫吸附(ELISA)法检测空腹胰岛素(FINS),计算胰岛素抵抗指数(HOMA-IR);运用苏木精-伊红(HE)染色法观察各组大鼠卵巢组织病理形态;采用实时荧光定量聚合酶链式反应(q PCR)法检测各组大鼠卵巢组织PI3K、Akt、NF-кB抑制蛋白激酶(IKK)、NF-κB、NF-κB抑制因子(IκB)m RNA表达水平。结果:模型组大鼠FINS、FBG、HOMAIR水平均明显高于正常组(P<0.05,P<0.01);阳性药物组大鼠上述指标水平均明显低于模型组(P<0.05),补肾健脾活血方低、高剂量组大鼠FINS、HOMA-IR水平均显著低于模型组(P<0.01);阳性药物组大鼠FINS水平明显高于补肾健脾活血方低、高剂量组(P<0.05),FBG水平明显低于补肾健脾活血方低、高剂量组(P<0.05);上述各指标补肾健脾活血方低、高剂量组组间比较,差异均无统计学意义(P>0.05)。正常组大鼠卵巢结构完整,可见各级发育卵泡及黄体;模型组大鼠卵巢组织呈典型PCOS-IR病理改变,即白膜增厚、皮质纤维化、囊状卵泡增多、黄体减少及闭锁卵泡增加;各给药组病理表现相似,均较模型组有不同程度改善,表现为囊状卵泡减少、闭锁卵泡减少,卵巢结构趋于恢复正常。模型组大鼠卵巢组织PI3K、Akt m RNA表达明显低于正常组(P<0.01),IKK、IκB、NF-κB m RNA表达明显高于正常组(P<0.05,P<0.01);补肾健脾活血方高剂量组大鼠上述指标较模型组均有明显改善(P<0.05,P<0.01),阳性药物组、补肾健脾活血方低剂量组Akt m RNA表达明显高于模型组(P<0.05);补肾健脾活血方高剂量组PI3K、Akt m RNA表达明显高于低剂量组和阳性药物组(P<0.05,P<0.01),IKK、NF-κB m RNA表达明显低于低剂量组和阳性药物组(P<0.05,P<0.01)。结论:补肾健脾活血方能有效改善PCOS-IR大鼠的胰岛素抵抗及卵巢多囊样病变,其机制可能与激活PI3K/Akt信号并抑制IKK/NF-κB通路有关。展开更多
基金the Medical Research Council(MR/R004544/1,MR/R004463/1,to RE)EU ERA-NET NEURON(AxonRepair grant,to BN)+1 种基金Fight for Sight(5119/5120,and 5065-5066,to RE)National Eye Research Centre(to RE).
文摘Much research has focused on the PI3-kinase and PTEN signaling pathway with the aim to stimulate repair of the injured central nervous system.Axons in the central nervous system fail to regenerate,meaning that injuries or diseases that cause loss of axonal connectivity have life-changing consequences.In 2008,genetic deletion of PTEN was identified as a means of stimulating robust regeneration in the optic nerve.PTEN is a phosphatase that opposes the actions of PI3-kinase,a family of enzymes that function to generate the membrane phospholipid PIP_(3) from PIP_(2)(phosphatidylinositol(3,4,5)-trisphosphate from phosphatidylinositol(4,5)-bisphosphate).Deletion of PTEN therefore allows elevated signaling downstream of PI3-kinase,and was initially demonstrated to promote axon regeneration by signaling through mTOR.More recently,additional mechanisms have been identified that contribute to the neuron-intrinsic control of regenerative ability.This review describes neuronal signaling pathways downstream of PI3-kinase and PIP3,and considers them in relation to both developmental and regenerative axon growth.We briefly discuss the key neuron-intrinsic mechanisms that govern regenerative ability,and describe how these are affected by signaling through PI3-kinase.We highlight the recent finding of a developmental decline in the generation of PIP_(3) as a key reason for regenerative failure,and summarize the studies that target an increase in signaling downstream of PI3-kinase to facilitate regeneration in the adult central nervous system.Finally,we discuss obstacles that remain to be overcome in order to generate a robust strategy for repairing the injured central nervous system through manipulation of PI3-kinase signaling.
文摘Chen et al demonstrated that regulator of G protein signaling(RGS)4 promotes gastric cancer(GC)progression by activating the focal adhesion kinase/phospha-tidyl-inositol-3-kinase/protein kinase B pathway and inducing epithelial-mesen-chymal transition.Although their multilevel approach integrating clinical data,functional assays,and xenograft models demonstrated a key role for RGS4 in GC pathogenesis,several limitations should be considered.The mechanism of the RGS4-focal adhesion kinase interaction remains unclear,specifically whether it involves direct binding or intermediaries.The clinical analysis of 90 patients lacks stratification by GC subtypes or immune features,potentially limiting generaliz-ability.Furthermore,fully validating RGS4’s oncogenic role requires additional studies,including functional assays in chemotherapy-resistant and metastatic cell lines,metastasis models including orthotopic implantation and tail vein injection,and comparison with other RGS family members.Addressing these via targeted mechanistic studies and expanded clinical validation could strengthen RGS4’s po-tential as a therapeutic target in GC.
文摘目的:观察基于补肾健脾法拟定的中药汤剂补肾健脾活血方对多囊卵巢综合征伴胰岛素抵抗(PCOS-IR)模型大鼠的干预作用,并从磷脂酰肌醇3-激酶/蛋白激酶B/核因子κB(PI3K/Akt/NF-κB)信号通路探讨其作用机制。方法:将30只雌性SD大鼠随机分为正常组6只和造模组24只,造模组采用高脂饮食联合来曲唑灌胃法构建PCOS-IR模型。造模组所有大鼠均造模成功,将造模成功的24只大鼠随机分为模型组、阳性药物组(二甲双胍,每日给药量0.195 g/kg)和补肾健脾活血方低剂量组(每日给药量14.3 g/kg)、高剂量组(每日给药量28.6 g/kg),每组6只。各治疗组大鼠每日灌胃给予相应药物,模型组与正常组大鼠每日灌胃给予等量生理盐水,均每日1次,连续14 d。末次给药结束后当天下午4时起各组大鼠禁食不禁水,第2日上午9时开始进行取材和指标检测。尾尖取血,使用血糖仪检测空腹血糖(FBG);眼眶静脉取血,采用酶联免疫吸附(ELISA)法检测空腹胰岛素(FINS),计算胰岛素抵抗指数(HOMA-IR);运用苏木精-伊红(HE)染色法观察各组大鼠卵巢组织病理形态;采用实时荧光定量聚合酶链式反应(q PCR)法检测各组大鼠卵巢组织PI3K、Akt、NF-кB抑制蛋白激酶(IKK)、NF-κB、NF-κB抑制因子(IκB)m RNA表达水平。结果:模型组大鼠FINS、FBG、HOMAIR水平均明显高于正常组(P<0.05,P<0.01);阳性药物组大鼠上述指标水平均明显低于模型组(P<0.05),补肾健脾活血方低、高剂量组大鼠FINS、HOMA-IR水平均显著低于模型组(P<0.01);阳性药物组大鼠FINS水平明显高于补肾健脾活血方低、高剂量组(P<0.05),FBG水平明显低于补肾健脾活血方低、高剂量组(P<0.05);上述各指标补肾健脾活血方低、高剂量组组间比较,差异均无统计学意义(P>0.05)。正常组大鼠卵巢结构完整,可见各级发育卵泡及黄体;模型组大鼠卵巢组织呈典型PCOS-IR病理改变,即白膜增厚、皮质纤维化、囊状卵泡增多、黄体减少及闭锁卵泡增加;各给药组病理表现相似,均较模型组有不同程度改善,表现为囊状卵泡减少、闭锁卵泡减少,卵巢结构趋于恢复正常。模型组大鼠卵巢组织PI3K、Akt m RNA表达明显低于正常组(P<0.01),IKK、IκB、NF-κB m RNA表达明显高于正常组(P<0.05,P<0.01);补肾健脾活血方高剂量组大鼠上述指标较模型组均有明显改善(P<0.05,P<0.01),阳性药物组、补肾健脾活血方低剂量组Akt m RNA表达明显高于模型组(P<0.05);补肾健脾活血方高剂量组PI3K、Akt m RNA表达明显高于低剂量组和阳性药物组(P<0.05,P<0.01),IKK、NF-κB m RNA表达明显低于低剂量组和阳性药物组(P<0.05,P<0.01)。结论:补肾健脾活血方能有效改善PCOS-IR大鼠的胰岛素抵抗及卵巢多囊样病变,其机制可能与激活PI3K/Akt信号并抑制IKK/NF-κB通路有关。
