TY - JOUR
T1 - Attenuation of Mouse Mesangial Cell Contractility by High Glucose and Mannitol
T2 - Involvement of Protein Kinase C and Focal Adhesion Kinase
AU - Chen, Jin Shuen
AU - Lee, Herng Sheng
AU - Jin, Jong Shiaw
AU - Chen, Ann
AU - Lin, Shih Hua
AU - Ka, Shuk Man
AU - Lin, Yuh Feng
PY - 2004
Y1 - 2004
N2 - Hyperglycemia and mannitol activate protein kinase C (PKC) and induce mesangial cell hypocontractility that subsequently may modulate renal function. Since focal adhesion kinase (FAK) activation is known to be linked with PKC activity, FAK may also be involved in mesangial cell contraction. To facilitate our understanding of the PKC- and FAK-modulating mechanism, we developed an in vitro model of mouse mesangial cell hypocontractility induced by hyperglycemia or mannitol. Mouse mesangial cells (CRL-1927) were exposed to: normal D-glucose (group N), high D-glucose (group H), and control groups at the same osmolality as H plus L-glucose (group L) and mannitol (group M). Changes in the planar surface area of cells in response to 1 IμM phorbol 12-myristate 13-acetate (PMA) were determined. Western blot analyses for PKC, phosphorylated (p)-PKC, tyrosine phosphorylation, FAK, and p-FAK were done on each of these four groups. The effects of mannitol in various doses on cell contraction and activation of PKC and FAK were also assayed. The planar surface areas of groups H and M both showed an attenuated change in response to PMA stimulation. Before PMA stimulation, the baseline PKC expression of groups H and M showed a higher expression of p-PKCα and δ than that seen in group N (p <0.05). Results of tyrosine phosphorylation and immunoprecipitation showed that FAK may be involved in this contraction process. The total amount of FAK showed no significant difference among the four experimental groups; however, p-FAK was found to have significantly increased in group M (p <0.05). The use of PKC and tyrosine kinase inhibitors reduced PMA-induced mesangial cell contraction in all four groups. Activation of PKCα, δ, and FAK with the resultant inhibition of mesangial cell contraction by mannitol was found to be dose-dependent. These results may provide a correlation between increased expression of several PKC isoforms and, in particular, increased phosphorylation levels of PKCα and δ and hypocontractility induced by high glucose and mannitol treatment. Furthermore, the mannitol-induced hypocontractility involving PKC and FAK occurred in a dose-dependent manner.
AB - Hyperglycemia and mannitol activate protein kinase C (PKC) and induce mesangial cell hypocontractility that subsequently may modulate renal function. Since focal adhesion kinase (FAK) activation is known to be linked with PKC activity, FAK may also be involved in mesangial cell contraction. To facilitate our understanding of the PKC- and FAK-modulating mechanism, we developed an in vitro model of mouse mesangial cell hypocontractility induced by hyperglycemia or mannitol. Mouse mesangial cells (CRL-1927) were exposed to: normal D-glucose (group N), high D-glucose (group H), and control groups at the same osmolality as H plus L-glucose (group L) and mannitol (group M). Changes in the planar surface area of cells in response to 1 IμM phorbol 12-myristate 13-acetate (PMA) were determined. Western blot analyses for PKC, phosphorylated (p)-PKC, tyrosine phosphorylation, FAK, and p-FAK were done on each of these four groups. The effects of mannitol in various doses on cell contraction and activation of PKC and FAK were also assayed. The planar surface areas of groups H and M both showed an attenuated change in response to PMA stimulation. Before PMA stimulation, the baseline PKC expression of groups H and M showed a higher expression of p-PKCα and δ than that seen in group N (p <0.05). Results of tyrosine phosphorylation and immunoprecipitation showed that FAK may be involved in this contraction process. The total amount of FAK showed no significant difference among the four experimental groups; however, p-FAK was found to have significantly increased in group M (p <0.05). The use of PKC and tyrosine kinase inhibitors reduced PMA-induced mesangial cell contraction in all four groups. Activation of PKCα, δ, and FAK with the resultant inhibition of mesangial cell contraction by mannitol was found to be dose-dependent. These results may provide a correlation between increased expression of several PKC isoforms and, in particular, increased phosphorylation levels of PKCα and δ and hypocontractility induced by high glucose and mannitol treatment. Furthermore, the mannitol-induced hypocontractility involving PKC and FAK occurred in a dose-dependent manner.
KW - Focal adhesion kinase
KW - Hyperglycemia
KW - Mannitol
KW - Mesangial cell
KW - Protein kinase C
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U2 - 10.1159/000076026
DO - 10.1159/000076026
M3 - Article
C2 - 14966364
AN - SCOPUS:1442328789
VL - 11
SP - 142
EP - 151
JO - Journal of Biomedical Science
JF - Journal of Biomedical Science
SN - 1021-7770
IS - 2
ER -