Previously, we reported that M-CSF induced monocyte survival through the activation of Akt, p38MAPK and Erk1/2 kinases. Here, we found that Src family kinases were upstream of these kinases and played a central role i...Previously, we reported that M-CSF induced monocyte survival through the activation of Akt, p38MAPK and Erk1/2 kinases. Here, we found that Src family kinases were upstream of these kinases and played a central role in regulating M-CSF-induced monocyte survival. We observed that M-CSF promoted c-Src activation in monocytes and MDMs in a time-dependent manner. Src inhibitors reduced M-CSF-mediated phosphorylation of the M-CSF receptor (M-CSFR), Akt, Erk1/2, and p38 MAPK. We also observed that Src directly phosphorylated the M-CSFR. Notably, the inhibitors blocked phosphorylation of specific tyrosine residues within the M-CSFR. We further demonstrated that the Src inhibitor, PP2, attenuated M-CSF-induced NF-κB activation and M-CSF-induced monocyte survival. These findings indicated that Src family kinases mediate monocyte survival through the regulation of receptor phosphorylation and modulation of downstream signaling events. Thus, we predict that targeting Src family kinases may have therapeutic implication in inflammatory diseases.展开更多
Spinal cord injury （SCI） is a devastating condition that produces significant changes in the life- style of patients. Many molecular and cellular events are triggered after the initial physical impact to the cord. T...Spinal cord injury （SCI） is a devastating condition that produces significant changes in the life- style of patients. Many molecular and cellular events are triggered after the initial physical impact to the cord. Two major phases have been described in the field of SCI： an acute phase and late phase. Most of the therapeutic strategies are focused on the late phase because this provides an opportunity to target cellular events like apoptosis, demyelination, scar formation and axonal outgrowth. In this mini-review, we will focus on two agents （tamoxifen and a Src kinase family inhibitor known as PP2） that have been shown in our laboratory to produce neuroprotective （increase cell survival） and/or regenerative （axonal outgrowth） actions. The animal model used in our laboratory is adult female rat （N250 g） with a moderate contusion （12.5 mm） to the spinal cord at the T10 level, using the MASCIS impactor device. Tamoxifen or PP2 was administered by implantation of a 15 mg pellet （Innovative Research of America, Sarasota, FL, USA） or by intraperitoneal injections （1.5 mg/kg, every 3 days）, respectively, to produce a long-term effect （28 days）. Tamoxifen and the Src kinase inhibitor, PP2, are drugs that in rats with a moderate spinal cord injury promote functional locomotor recovery, increase spared white matter tissue, and stimulate axonal outgrowth. Moreover, tamoxifen reduces the formation of reactive oxygen species. Therefore, these drugs are possible therapeutic agents that have a neuroprotective/regen- erative activity in vertebrates with SCI.展开更多
AIM: To study the role of focal adhesion kinase (FAK) and its association with Src in hepatocyte growth factor (HGF)-induced cell signaling in cholangiocarcinoma progression.METHODS: Previously isolated HuCCA-1 cells ...AIM: To study the role of focal adhesion kinase (FAK) and its association with Src in hepatocyte growth factor (HGF)-induced cell signaling in cholangiocarcinoma progression.METHODS: Previously isolated HuCCA-1 cells were re-characterized by immunofluorescent staining and reverse transcriptase-polymerase chain reaction assay for the expression of cytokeratin 19, HGF and c-Met mRNA. Cultured HuCCA-1 cells were treated with HGF and determined for cell proliferation and invasion effects by MTT and invasion assays. Western blotting, immunoprecipitation, and co-immunoprecipitation were also performed to study the phosphorylation and interaction of FAK and Src. A novel Src inhibitor (AZM555130) was applied in cultures to investigate the effects on FAK phosphorylation inhibition and on cell proliferation and invasion.RESULTS: HGF enhanced HuCCA-1 cell proliferation and invasion by mediating FAK and Src phosphorylations.FAK-Src interaction occurred in a time-dependent manner that Src was proved to be an upstream signaling molecule to FAK. The inhibitor to Src decreased FAK phosphorylation level in correlation with the reduction of cell proliferation and invasion.CONCLUSION: FAK plays a significant role in signaling pathway of HGF-responsive cell line derived from cholangiocarcinoma. Autophosphorylated Src, induced by HGF, mediates Src kinase activation, which subsequently phosphorylates its substrate, FAK, and signals to cell proliferation and invasion.展开更多
文摘Previously, we reported that M-CSF induced monocyte survival through the activation of Akt, p38MAPK and Erk1/2 kinases. Here, we found that Src family kinases were upstream of these kinases and played a central role in regulating M-CSF-induced monocyte survival. We observed that M-CSF promoted c-Src activation in monocytes and MDMs in a time-dependent manner. Src inhibitors reduced M-CSF-mediated phosphorylation of the M-CSF receptor (M-CSFR), Akt, Erk1/2, and p38 MAPK. We also observed that Src directly phosphorylated the M-CSFR. Notably, the inhibitors blocked phosphorylation of specific tyrosine residues within the M-CSFR. We further demonstrated that the Src inhibitor, PP2, attenuated M-CSF-induced NF-κB activation and M-CSF-induced monocyte survival. These findings indicated that Src family kinases mediate monocyte survival through the regulation of receptor phosphorylation and modulation of downstream signaling events. Thus, we predict that targeting Src family kinases may have therapeutic implication in inflammatory diseases.
基金partially supported by the MBRS-RISE Program(R25 GM061838)COBRE(5P20-GM103642)
文摘Spinal cord injury （SCI） is a devastating condition that produces significant changes in the life- style of patients. Many molecular and cellular events are triggered after the initial physical impact to the cord. Two major phases have been described in the field of SCI： an acute phase and late phase. Most of the therapeutic strategies are focused on the late phase because this provides an opportunity to target cellular events like apoptosis, demyelination, scar formation and axonal outgrowth. In this mini-review, we will focus on two agents （tamoxifen and a Src kinase family inhibitor known as PP2） that have been shown in our laboratory to produce neuroprotective （increase cell survival） and/or regenerative （axonal outgrowth） actions. The animal model used in our laboratory is adult female rat （N250 g） with a moderate contusion （12.5 mm） to the spinal cord at the T10 level, using the MASCIS impactor device. Tamoxifen or PP2 was administered by implantation of a 15 mg pellet （Innovative Research of America, Sarasota, FL, USA） or by intraperitoneal injections （1.5 mg/kg, every 3 days）, respectively, to produce a long-term effect （28 days）. Tamoxifen and the Src kinase inhibitor, PP2, are drugs that in rats with a moderate spinal cord injury promote functional locomotor recovery, increase spared white matter tissue, and stimulate axonal outgrowth. Moreover, tamoxifen reduces the formation of reactive oxygen species. Therefore, these drugs are possible therapeutic agents that have a neuroprotective/regen- erative activity in vertebrates with SCI.
基金Supported by the Royal Golden Jubilee PhD Program of the Thailand Research Fund (RGJ/PHD/0112/2542)
文摘AIM: To study the role of focal adhesion kinase (FAK) and its association with Src in hepatocyte growth factor (HGF)-induced cell signaling in cholangiocarcinoma progression.METHODS: Previously isolated HuCCA-1 cells were re-characterized by immunofluorescent staining and reverse transcriptase-polymerase chain reaction assay for the expression of cytokeratin 19, HGF and c-Met mRNA. Cultured HuCCA-1 cells were treated with HGF and determined for cell proliferation and invasion effects by MTT and invasion assays. Western blotting, immunoprecipitation, and co-immunoprecipitation were also performed to study the phosphorylation and interaction of FAK and Src. A novel Src inhibitor (AZM555130) was applied in cultures to investigate the effects on FAK phosphorylation inhibition and on cell proliferation and invasion.RESULTS: HGF enhanced HuCCA-1 cell proliferation and invasion by mediating FAK and Src phosphorylations.FAK-Src interaction occurred in a time-dependent manner that Src was proved to be an upstream signaling molecule to FAK. The inhibitor to Src decreased FAK phosphorylation level in correlation with the reduction of cell proliferation and invasion.CONCLUSION: FAK plays a significant role in signaling pathway of HGF-responsive cell line derived from cholangiocarcinoma. Autophosphorylated Src, induced by HGF, mediates Src kinase activation, which subsequently phosphorylates its substrate, FAK, and signals to cell proliferation and invasion.
基金Acknowledgements： This work was supported by the Natural Science Foundation of Jiangsu Province, China （No. 04KJB310082） and the Science and Technology Development Foundation of Nanjing Medical University （No. 06NMUZ002）.
