Change of p16^INK4a and PNCA Protein Expression in Myocardium after Injection of hIGF-1 Gene Modified Skeletal Myoblasts into Post-infarction Rats

【摘要】 This study examined the change of p16INK4a and PNCA protein expression in myocardium after injection of hIGF-1 gene modified skeletal myoblasts into post-infarction rats. HIGF-1 gene modified skeletal myoblasts (hIGF-1-myoblasts) were injected into hind limb muscles of 18 post-infraction rats (experimental group). Primary-myoblasts were injected into 18 post-infraction rats (control group) and 12 non-infarction rats (sham group). Expression of p16INK4a and PCNA pro- tein in myocardiums were separately detected immunocytochemically 1, 2 and 4 weeks after the inuection. The level of hIGF-1 and rIGF-1 protein in serum and myocardium were detected by en- zyme-linked immunosorbent assay (ELISA). Compared with the sham group, the percentage of p16INK4a and PCNA positive cells reached a peak after 1 week in the control group and the experimental group (P<0.01). Moreover, the percentage of p16INK4a-positive cells in the experimental group was lower than in control group whereas the percentage of PCNA-positive cells was lower in the control group than in the experimental group (P<0.01). The percentage of p16INK4a-positive cells in the experimental group and the percentage of PCNA-positive cells in the control group were close to that in the sham group from the 2nd week (P>0.05). ELISA analysis disclosed that the myocardium level of rIGF-1 protein increased gradually in the controls and especially in the experimental group (P<0.01). The serum level of rIGF-1 decreased significantly in post-infraction rats, but these conditions were improved in the experimental group (P<0.01). The hIGF-1 protein in serum and myocar- dium were detected from the 1st week to the 4th week in the experimental group. Statistical analysis revealed significant associations of myocardium level of hIGF-1 protein with expression of p16INK4a and PCNA protein (r=–0.323, P<0.05; r=0.647, P<0.01). It is concluded that genetically hIGF-1-myoblast provides a means for constant synthesis and release of hIGF-1. It could not only improve the expression of rIGF-1 and PCNA protein in myocardium, but also suppress the expression of p16INK4a protein for 30 days in post-infraction rats. Myoblasts-mediated IGF-1 gene therapy may provide a new alternative for the clinical treatment of heart failure.更多还原

【Abstract】 This study examined the change of p16INK4a and PNCA protein expression in myocardium after injeThis study examined the change of p16INK4a and PNCA protein expression in myocardium after injection of hIGF-1 gene modified skeletal myoblasts into post-infarction rats. HIGF-1 gene modified skeletal myoblasts (hIGF-1-myoblasts) were injected into hind limb muscles of 18 post-infraction rats (experimental group). Primary-myoblasts were injected into 18 post-infraction rats (control group) and 12 non-infarction rats (sham group). Expression of p16INK4a and PCNA pro- tein in myocardiums were separately detected immunocytochemically 1, 2 and 4 weeks after the inuection. The level of hIGF-1 and rIGF-1 protein in serum and myocardium were detected by en- zyme-linked immunosorbent assay (ELISA). Compared with the sham group, the percentage of p16INK4a and PCNA positive cells reached a peak after 1 week in the control group and the experimental group (P<0.01). Moreover, the percentage of p16INK4a-positive cells in the experimental group was lower than in control group whereas the percentage of PCNA-positive cells was lower in the control group than in the experimental group (P<0.01). The percentage of p16INK4a-positive cells in the experimental group and the percentage of PCNA-positive cells in the control group were close to that in the sham group from the 2nd week (P>0.05). ELISA analysis disclosed that the myocardium level of rIGF-1 protein increased gradually in the controls and especially in the experimental group (P<0.01). The serum level of rIGF-1 decreased significantly in post-infraction rats, but these conditions were improved in the experimental group (P<0.01). The hIGF-1 protein in serum and myocar- dium were detected from the 1st week to the 4th week in the experimental group. Statistical analysis revealed significant associations of myocardium level of hIGF-1 protein with expression of p16INK4a and PCNA protein (r=–0.323, P<0.05; r=0.647, P<0.01). It is concluded that genetically hIGF-1-myoblast provides a means for constant synthesis and release of hIGF-1. It could not only improve the expression of rIGF-1 and PCNA protein in myocardium, but also suppress the expression of p16INK4a protein for 30 days in post-infraction rats. Myoblasts-mediated IGF-1 gene therapy may provide a new alternative for the clinical treatment of heart failure.更多还原