Objective:Phenolic acids widely exist in the human diet and exert beneficial effects such as improving glucose metabolism.It is not clear whether phenolic acids or their metabolites play a major role in vivo.In this s...Objective:Phenolic acids widely exist in the human diet and exert beneficial effects such as improving glucose metabolism.It is not clear whether phenolic acids or their metabolites play a major role in vivo.In this study,caffeic acid(CA)and ferulic acid(FA),the two most ingested phenolic acids,and their glucuronic acid metabolites,caffeic-4’-O-glucuronide(CA4G)and ferulic-4’-O-glucuronide(FA4G),were investigated.Methods:Three insulin resistance models in vitro were established by using TNF-a,insulin and palmitic acid(PA)in HepG2 cells,respectively.We compared the effects of FA,FA4G,CA and CA4G on glucose metabolism in these models by measuring the glucose consumption levels.The potential targets and related pathways were predicted by network pharmacology.Fluorescence quenching measurement was used to analyze the binding between the compounds and the predicted target.To investigate the binding mode,molecular docking was performed.Then,we performed membrane recruitment assays of the AKT pleckstrin homology(PH)domain with the help of the PH-GFP plasmid.AKT enzymatic activity was determined to compare the effects between the metabolites with their parent compounds.Finally,the downstream signaling pathway of AKT was investigated by Western blot analysis.Results:The results showed that CA4G and FA4G were more potent than their parent compounds in increasing glucose consumption.AKT was predicted to be the key target of CA4G and FA4G by network pharmacology analysis.The fluorescence quenching test confirmed the more potent binding to AKT of the two metabolites compared to their parent compounds.The molecular docking results indicated that the carbonyl group in the glucuronic acid structure of CA4G and FA4G might bind to the PH domain of AKT at the key Arg-25 site.CA4G and FA4G inhibited the translocation of the AKT PH domain to the membrane,while increasing the activity of AKT.Western blot analysis demonstrated that the metabolites could increase the phosphorylation of AKT and downstream glycogen synthase kinase 3βin the AKT signaling pathway to increase glucose consumption.Conclusion:In conclusion,our results suggested that the metabolites of phenolic acids,which contain glucuronic acid,are the key active substances and that they activate AKT by targeting the PH domain,thus improving glucose metabolism.展开更多
Kindlin-2 belongs to a subfamily of FERM domain con-taining proteins,which plays key roles in activating integrin transmembrane receptors and mediating cell adhesion.Compared to conventional FERM domains,kindlin-2 FER...Kindlin-2 belongs to a subfamily of FERM domain con-taining proteins,which plays key roles in activating integrin transmembrane receptors and mediating cell adhesion.Compared to conventional FERM domains,kindlin-2 FERM contains an inserted pleckstrin homology(PH)domain that specifically binds to phosphatidy-linositol(3,4,5)trisphosphate(PIP3)and regulates the kindlin-2 function.We have determined the crystal struc-ture of kindlin-2 PH domain at 1.9Åresolution,which reveals a conserved PH domain fold with a highly charged and open binding pocket for PIP3 head group.Structural comparison with a previously reported solution structure of kindlin-2 PH domain bound to PIP3 head group reveals that upon PIP3 insertion,there is a significant conformational change of both the highly positively charged loop at the entry of the PIP3 binding pocket and the entireβbarrel of the PH domain.We propose that such“induced-fit”type change is crucial for the tight binding of PIP3 to anchor kindlin-2 onto the membrane surface,thereby promoting its binding to integrins.Our results provide important structural insight into kindlin-2-mediated membrane anchoring and integrin activation.展开更多
Background： Ovarian serous adenocarcinoma can be divided into low- and high-grade tumors, which exhibit substantial differences in pathogenesis, clinicopathology, and prognosis. This study aimed to investigate the d...Background： Ovarian serous adenocarcinoma can be divided into low- and high-grade tumors, which exhibit substantial differences in pathogenesis, clinicopathology, and prognosis. This study aimed to investigate the difl＇erences in the PH domain leucine-rich repeat protein phosphatase （PHLPP）, tbrkhead llomeobox type O3a （FoxO3a）, and RAD51 protein expressions, and their associations with prognosis in patients with low- and high-grade ovarian serous adenocarcinomas. Methods： The PH LPP, FoxO3a, and RA D51 protein expressions were examined in 94 high- and 26 low-grade ovarian serous adenocarcinomas by immunohistochemistry. The differences in expression and their relationships with pathological features and prognosis were analyzed. Results： In high-grade serous adenocarcinomas, the positive rates of PHLPP and goxO3a were 24.5% and 26.6%, while in low-grade tumors, they were 23.1% and 26.9%, respectively （P 〈 0.05 vs. the control specimens; low- vs. high-grade： P 〉 0.（15）. The positive rates of RAD51 were 70.2% and 65.4% in high- and low-grade serous adenocarcinomas, respectively （P 〈 0.（15 vs. the control specimens; low- vs. high-grade： P 〉 0.05）. Meanwhile, in high-grade tumors, Stage Ⅲ/Ⅳ tumors and lymph node and omental metastases were significantly associated with lower PHLPP and FoxO3a and higher RAD51 expression. The 5-year survival rates of patients with PHLPP- and FoxO3a-positive high-grade tumors （43.5% and 36.0%） were significantly higher than in patients with PHLPP-negative tumors （5.6% and 7.2%, respectively; P 〈 0.05）. Similarly, the 5-year survival rate of RAD5 l-positive patients （3.0%） was significantly lower than in negative patients （42.9%： P〈 0.05）. In low-grade tumors, the PHLPP, FoxO3a, and RAD51 expressions were not significantly correlated with lymph node metastasis, omental metastasis, Federation of Gynecology and Obstetrics stage, or prognosis. Conclusions： Abnormal PHLPP, FoxO3a, and RAD51 protein expressions may be involved in the development of high- and low-grade ovarian serous adenocarcinomas, suggesting conlmon molecular pathways. Decreased PH LPP and FoxO3a and increased RAD51 protein expression may be important molecular markers for poor prognosis, and RAD51 may be an independent prognosis factor, of high-grade, but not low-grade, ovarian serous adenocarcinomas.展开更多
PH(pleckstrin homology)domains are well known to bind membrane phosphoinositides with different specificities and direct PH domain-containing proteins to discrete subcellular compartments with assistances of alternati...PH(pleckstrin homology)domains are well known to bind membrane phosphoinositides with different specificities and direct PH domain-containing proteins to discrete subcellular compartments with assistances of alternative binding partners.PH domain-containing proteins have been found to be involved in a wide range of cellular events,including signalling,cytoskeleton rearrangement and vesicular trafficking.Here we showed that a novel PH domain-containing protein,PEPP2(also known as PLEKHA5),displays moderate phosphoinositide binding specificity.Full length PEPP2 was observed to variably associate with both the plasma membrane and microtubules.The membrane-associated PEPP2 nucleated at cell-cell contacts and the leading edge of migrating cells.Overexpression of PEPP2 increased membrane microviscosity,indicating a potential role for PEPP2 in regulating function of microtubule-dependent membrane functions.展开更多
BACKGROUND Adaptor protein,phosphotyrosine interacting with PH domain and leucine zipper 1(APPL1)plays a crucial role in regulating insulin signaling and glucose metabolism.Mutations in the APPL1 gene have been associ...BACKGROUND Adaptor protein,phosphotyrosine interacting with PH domain and leucine zipper 1(APPL1)plays a crucial role in regulating insulin signaling and glucose metabolism.Mutations in the APPL1 gene have been associated with the development of maturity-onset diabetes of the young type 14(MODY14).Currently,only two mutations[c.1655T>A(p.Leu552*)and c.281G>A p.(Asp94Asn)]have been identified in association with this disease.Given the limited understanding of MODY14,it is imperative to identify additional cases and carry out comprehensive research on MODY14 and APPL1 mutations.AIM To assess the pathogenicity of APPL1 gene mutations in diabetic patients and to characterize the functional role of the APPL1 domain.METHODS Patients exhibiting clinical signs and a medical history suggestive of MODY were screened for the study.Whole exome sequencing was performed on the patients as well as their family members.The pathogenicity of the identified APPL1 variants was predicted on the basis of bioinformatics analysis.In addition,the pathogenicity of the novel APPL1 variant was preliminarily evaluated through in vitro functional experiments.Finally,the impact of these variants on APPL1 protein expression and the insulin pathway were assessed,and the potential mechanism underlying the interaction between the APPL1 protein and the insulin receptor was further explored.RESULTS A total of five novel mutations were identified,including four missense mutations(Asp632Tyr,Arg633His,Arg532Gln,and Ile642Met)and one intronic mutation(1153-16A>T).Pathogenicity prediction analysis revealed that the Arg532Gln was pathogenic across all predictions.The Asp632Tyr and Arg633His variants also had pathogenicity based on MutationTaster.In addition,multiple alignment of amino acid sequences showed that the Arg532Gln,Asp632Tyr,and Arg633His variants were conserved across different species.Moreover,in in vitro functional experiments,both the c.1894G>T(at Asp632Tyr)and c.1595G>A(at Arg532Gln)mutations were found to downregulate the expression of APPL1 on both protein and mRNA levels,indicating their pathogenic nature.Therefore,based on the patient’s clinical and family history,combined with the results from bioinformatics analysis and functional experiment,the c.1894G>T(at Asp632Tyr)and c.1595G>A(at Arg532Gln)mutations were classified as pathogenic mutations.Importantly,all these mutations were located within the phosphotyrosinebinding domain of APPL1,which plays a critical role in the insulin sensitization effect.CONCLUSION This study provided new insights into the pathogenicity of APPL1 gene mutations in diabetes and revealed a potential target for the diagnosis and treatment of the disease.展开更多
The serine/threonine protein kinase B(PKB) is related to cellular survival and regulation. PKB is composed of PH domain, catalytic domain and carboxyl terminal regulator domain. The PH domain of PKB is crucial to the ...The serine/threonine protein kinase B(PKB) is related to cellular survival and regulation. PKB is composed of PH domain, catalytic domain and carboxyl terminal regulator domain. The PH domain of PKB is crucial to the activation of kinase. In order to investigate the function and the structure function relationship of PKB, the cDNA coding fragment of PKB PH domain was amplified from human dental pulp mRNA by RT PCR and cloned into pMD18 T vector to analyze the sequence. The result showed that DNA sequence of cloned human PKB PH domain was consistent with that reported previously. To express PKB PH domain, the cDNA was subcloned into expression vector pRSET A which was then transformed into E.coli BL21(DE3) pLysS, and the strain highly expressing soluble 6His PKB PH domain in minimal medium was obtained. The fusion protein was purified by Ni 2+ NTA agarose beads. The secondary structure of the purified 6His PKB PH domain fusion protein was analysed by circular dichroism. The results indicated that the PH domain was composed of α helix 1 7%,β pleated sheet 80 5% and radom coli 17 8%.展开更多
目的探讨磷酸酶PHLPP1在人脐静脉内皮细胞(HUVEC)中的基础表达及转基因对其增殖的影响。方法体外培养的HUVEC分3组处理,分别为未转染组、转染pcDNA3-GFP组和转染pcDNA3HA-PHLPP组。通过构建pcDNA3HA-PHLPP1质粒并瞬时转染HUVEC。以细胞...目的探讨磷酸酶PHLPP1在人脐静脉内皮细胞(HUVEC)中的基础表达及转基因对其增殖的影响。方法体外培养的HUVEC分3组处理,分别为未转染组、转染pcDNA3-GFP组和转染pcDNA3HA-PHLPP组。通过构建pcDNA3HA-PHLPP1质粒并瞬时转染HUVEC。以细胞计数及噻唑盐比色法测定细胞增殖能力,Western blot ting定量磷酸酶PHLPP1蛋白表达水平。结果基础状态下HUVEC不表达PHLPP1。转染pcDNA3HA-PHLPP1组明显增加PHLPP1表达,与正常对照组、pcDNA3-GFP组比较差异显著(均P<0.01)。3组的细胞增殖指标无明显差异(P>0.05),其中MTT吸收度A值分别是0.134±0.015,0.133±0.014,0.137±0.016,细胞计数为(8.293±0.962)×105,(7.937±0.101)×105,8.127±0.112)×105。结论 PHLPP可能不是调节HUVEC增殖的最重要信号蛋白。展开更多
Objective To investigate the effects of insulin-like growth factor-1 （IGF-1） and oxidized low density lipoprotein （oxLDL） on expression ofphosphatase PHLPP 1 in vascular smooth muscle cells （VSMCs）. Methods Rabb...Objective To investigate the effects of insulin-like growth factor-1 （IGF-1） and oxidized low density lipoprotein （oxLDL） on expression ofphosphatase PHLPP 1 in vascular smooth muscle cells （VSMCs）. Methods Rabbit aortic VSMCs were cultured. VSMCs proliferation ability was determined by measuring cell number and mitochondrial dehydrogenase （MD） activity with MTT assay. Western blot was used to detect the protein expression ofphosphatase PHLPP1. Results IGF-1 （100ug/L） increased cell number and MD activity to 3.02 and 3.59 times of that in control group, oxLDL（501xg/ml） elevated the above two parameters to 2.03 and 2.91 times respectively. Western blot showed that IGF-1 and oxLDL inhibited the expression of PHLPPI to 39.27% and 40.26% of the control group （P〈0.01 ）. Conclusion IGF- 1 and oxLDL may enhance the proliferation of VSMCs by decreasing the expression ofphosphatase PHLPP 1.展开更多
基金funded by Guangxi Innovation-driven Development 20 Special Foundation Project(No.AA18118049)Guangxi Key Laboratory of Efficacy Study on Chinese Materia Medica(19245-1)“the Fundamental Research Funds for the Central Universities”of Nankai University(No.63191723)。
文摘Objective:Phenolic acids widely exist in the human diet and exert beneficial effects such as improving glucose metabolism.It is not clear whether phenolic acids or their metabolites play a major role in vivo.In this study,caffeic acid(CA)and ferulic acid(FA),the two most ingested phenolic acids,and their glucuronic acid metabolites,caffeic-4’-O-glucuronide(CA4G)and ferulic-4’-O-glucuronide(FA4G),were investigated.Methods:Three insulin resistance models in vitro were established by using TNF-a,insulin and palmitic acid(PA)in HepG2 cells,respectively.We compared the effects of FA,FA4G,CA and CA4G on glucose metabolism in these models by measuring the glucose consumption levels.The potential targets and related pathways were predicted by network pharmacology.Fluorescence quenching measurement was used to analyze the binding between the compounds and the predicted target.To investigate the binding mode,molecular docking was performed.Then,we performed membrane recruitment assays of the AKT pleckstrin homology(PH)domain with the help of the PH-GFP plasmid.AKT enzymatic activity was determined to compare the effects between the metabolites with their parent compounds.Finally,the downstream signaling pathway of AKT was investigated by Western blot analysis.Results:The results showed that CA4G and FA4G were more potent than their parent compounds in increasing glucose consumption.AKT was predicted to be the key target of CA4G and FA4G by network pharmacology analysis.The fluorescence quenching test confirmed the more potent binding to AKT of the two metabolites compared to their parent compounds.The molecular docking results indicated that the carbonyl group in the glucuronic acid structure of CA4G and FA4G might bind to the PH domain of AKT at the key Arg-25 site.CA4G and FA4G inhibited the translocation of the AKT PH domain to the membrane,while increasing the activity of AKT.Western blot analysis demonstrated that the metabolites could increase the phosphorylation of AKT and downstream glycogen synthase kinase 3βin the AKT signaling pathway to increase glucose consumption.Conclusion:In conclusion,our results suggested that the metabolites of phenolic acids,which contain glucuronic acid,are the key active substances and that they activate AKT by targeting the PH domain,thus improving glucose metabolism.
基金supported by the 973 Program of the Ministry of Science and Technology of China(Grant Nos.2011CB911101 and 2012CB910304).
文摘Kindlin-2 belongs to a subfamily of FERM domain con-taining proteins,which plays key roles in activating integrin transmembrane receptors and mediating cell adhesion.Compared to conventional FERM domains,kindlin-2 FERM contains an inserted pleckstrin homology(PH)domain that specifically binds to phosphatidy-linositol(3,4,5)trisphosphate(PIP3)and regulates the kindlin-2 function.We have determined the crystal struc-ture of kindlin-2 PH domain at 1.9Åresolution,which reveals a conserved PH domain fold with a highly charged and open binding pocket for PIP3 head group.Structural comparison with a previously reported solution structure of kindlin-2 PH domain bound to PIP3 head group reveals that upon PIP3 insertion,there is a significant conformational change of both the highly positively charged loop at the entry of the PIP3 binding pocket and the entireβbarrel of the PH domain.We propose that such“induced-fit”type change is crucial for the tight binding of PIP3 to anchor kindlin-2 onto the membrane surface,thereby promoting its binding to integrins.Our results provide important structural insight into kindlin-2-mediated membrane anchoring and integrin activation.
文摘Background： Ovarian serous adenocarcinoma can be divided into low- and high-grade tumors, which exhibit substantial differences in pathogenesis, clinicopathology, and prognosis. This study aimed to investigate the difl＇erences in the PH domain leucine-rich repeat protein phosphatase （PHLPP）, tbrkhead llomeobox type O3a （FoxO3a）, and RAD51 protein expressions, and their associations with prognosis in patients with low- and high-grade ovarian serous adenocarcinomas. Methods： The PH LPP, FoxO3a, and RA D51 protein expressions were examined in 94 high- and 26 low-grade ovarian serous adenocarcinomas by immunohistochemistry. The differences in expression and their relationships with pathological features and prognosis were analyzed. Results： In high-grade serous adenocarcinomas, the positive rates of PHLPP and goxO3a were 24.5% and 26.6%, while in low-grade tumors, they were 23.1% and 26.9%, respectively （P 〈 0.05 vs. the control specimens; low- vs. high-grade： P 〉 0.（15）. The positive rates of RAD51 were 70.2% and 65.4% in high- and low-grade serous adenocarcinomas, respectively （P 〈 0.（15 vs. the control specimens; low- vs. high-grade： P 〉 0.05）. Meanwhile, in high-grade tumors, Stage Ⅲ/Ⅳ tumors and lymph node and omental metastases were significantly associated with lower PHLPP and FoxO3a and higher RAD51 expression. The 5-year survival rates of patients with PHLPP- and FoxO3a-positive high-grade tumors （43.5% and 36.0%） were significantly higher than in patients with PHLPP-negative tumors （5.6% and 7.2%, respectively; P 〈 0.05）. Similarly, the 5-year survival rate of RAD5 l-positive patients （3.0%） was significantly lower than in negative patients （42.9%： P〈 0.05）. In low-grade tumors, the PHLPP, FoxO3a, and RAD51 expressions were not significantly correlated with lymph node metastasis, omental metastasis, Federation of Gynecology and Obstetrics stage, or prognosis. Conclusions： Abnormal PHLPP, FoxO3a, and RAD51 protein expressions may be involved in the development of high- and low-grade ovarian serous adenocarcinomas, suggesting conlmon molecular pathways. Decreased PH LPP and FoxO3a and increased RAD51 protein expression may be important molecular markers for poor prognosis, and RAD51 may be an independent prognosis factor, of high-grade, but not low-grade, ovarian serous adenocarcinomas.
基金sponsored by the Science Foundation of the Ministry of Education of China(51208011)the setup grant of Jinan University(51207016).
文摘PH(pleckstrin homology)domains are well known to bind membrane phosphoinositides with different specificities and direct PH domain-containing proteins to discrete subcellular compartments with assistances of alternative binding partners.PH domain-containing proteins have been found to be involved in a wide range of cellular events,including signalling,cytoskeleton rearrangement and vesicular trafficking.Here we showed that a novel PH domain-containing protein,PEPP2(also known as PLEKHA5),displays moderate phosphoinositide binding specificity.Full length PEPP2 was observed to variably associate with both the plasma membrane and microtubules.The membrane-associated PEPP2 nucleated at cell-cell contacts and the leading edge of migrating cells.Overexpression of PEPP2 increased membrane microviscosity,indicating a potential role for PEPP2 in regulating function of microtubule-dependent membrane functions.
基金Supported by the National Natural Science Foundation,No.81974124and Taishan Scholar Project,No.tsqn20161071.
文摘BACKGROUND Adaptor protein,phosphotyrosine interacting with PH domain and leucine zipper 1(APPL1)plays a crucial role in regulating insulin signaling and glucose metabolism.Mutations in the APPL1 gene have been associated with the development of maturity-onset diabetes of the young type 14(MODY14).Currently,only two mutations[c.1655T>A(p.Leu552*)and c.281G>A p.(Asp94Asn)]have been identified in association with this disease.Given the limited understanding of MODY14,it is imperative to identify additional cases and carry out comprehensive research on MODY14 and APPL1 mutations.AIM To assess the pathogenicity of APPL1 gene mutations in diabetic patients and to characterize the functional role of the APPL1 domain.METHODS Patients exhibiting clinical signs and a medical history suggestive of MODY were screened for the study.Whole exome sequencing was performed on the patients as well as their family members.The pathogenicity of the identified APPL1 variants was predicted on the basis of bioinformatics analysis.In addition,the pathogenicity of the novel APPL1 variant was preliminarily evaluated through in vitro functional experiments.Finally,the impact of these variants on APPL1 protein expression and the insulin pathway were assessed,and the potential mechanism underlying the interaction between the APPL1 protein and the insulin receptor was further explored.RESULTS A total of five novel mutations were identified,including four missense mutations(Asp632Tyr,Arg633His,Arg532Gln,and Ile642Met)and one intronic mutation(1153-16A>T).Pathogenicity prediction analysis revealed that the Arg532Gln was pathogenic across all predictions.The Asp632Tyr and Arg633His variants also had pathogenicity based on MutationTaster.In addition,multiple alignment of amino acid sequences showed that the Arg532Gln,Asp632Tyr,and Arg633His variants were conserved across different species.Moreover,in in vitro functional experiments,both the c.1894G>T(at Asp632Tyr)and c.1595G>A(at Arg532Gln)mutations were found to downregulate the expression of APPL1 on both protein and mRNA levels,indicating their pathogenic nature.Therefore,based on the patient’s clinical and family history,combined with the results from bioinformatics analysis and functional experiment,the c.1894G>T(at Asp632Tyr)and c.1595G>A(at Arg532Gln)mutations were classified as pathogenic mutations.Importantly,all these mutations were located within the phosphotyrosinebinding domain of APPL1,which plays a critical role in the insulin sensitization effect.CONCLUSION This study provided new insights into the pathogenicity of APPL1 gene mutations in diabetes and revealed a potential target for the diagnosis and treatment of the disease.
文摘The serine/threonine protein kinase B(PKB) is related to cellular survival and regulation. PKB is composed of PH domain, catalytic domain and carboxyl terminal regulator domain. The PH domain of PKB is crucial to the activation of kinase. In order to investigate the function and the structure function relationship of PKB, the cDNA coding fragment of PKB PH domain was amplified from human dental pulp mRNA by RT PCR and cloned into pMD18 T vector to analyze the sequence. The result showed that DNA sequence of cloned human PKB PH domain was consistent with that reported previously. To express PKB PH domain, the cDNA was subcloned into expression vector pRSET A which was then transformed into E.coli BL21(DE3) pLysS, and the strain highly expressing soluble 6His PKB PH domain in minimal medium was obtained. The fusion protein was purified by Ni 2+ NTA agarose beads. The secondary structure of the purified 6His PKB PH domain fusion protein was analysed by circular dichroism. The results indicated that the PH domain was composed of α helix 1 7%,β pleated sheet 80 5% and radom coli 17 8%.
文摘目的探讨磷酸酶PHLPP1在人脐静脉内皮细胞(HUVEC)中的基础表达及转基因对其增殖的影响。方法体外培养的HUVEC分3组处理,分别为未转染组、转染pcDNA3-GFP组和转染pcDNA3HA-PHLPP组。通过构建pcDNA3HA-PHLPP1质粒并瞬时转染HUVEC。以细胞计数及噻唑盐比色法测定细胞增殖能力,Western blot ting定量磷酸酶PHLPP1蛋白表达水平。结果基础状态下HUVEC不表达PHLPP1。转染pcDNA3HA-PHLPP1组明显增加PHLPP1表达,与正常对照组、pcDNA3-GFP组比较差异显著(均P<0.01)。3组的细胞增殖指标无明显差异(P>0.05),其中MTT吸收度A值分别是0.134±0.015,0.133±0.014,0.137±0.016,细胞计数为(8.293±0.962)×105,(7.937±0.101)×105,8.127±0.112)×105。结论 PHLPP可能不是调节HUVEC增殖的最重要信号蛋白。
文摘Objective To investigate the effects of insulin-like growth factor-1 （IGF-1） and oxidized low density lipoprotein （oxLDL） on expression ofphosphatase PHLPP 1 in vascular smooth muscle cells （VSMCs）. Methods Rabbit aortic VSMCs were cultured. VSMCs proliferation ability was determined by measuring cell number and mitochondrial dehydrogenase （MD） activity with MTT assay. Western blot was used to detect the protein expression ofphosphatase PHLPP1. Results IGF-1 （100ug/L） increased cell number and MD activity to 3.02 and 3.59 times of that in control group, oxLDL（501xg/ml） elevated the above two parameters to 2.03 and 2.91 times respectively. Western blot showed that IGF-1 and oxLDL inhibited the expression of PHLPPI to 39.27% and 40.26% of the control group （P〈0.01 ）. Conclusion IGF- 1 and oxLDL may enhance the proliferation of VSMCs by decreasing the expression ofphosphatase PHLPP 1.
