蛋白激酶A在TGF-β_1刺激增生性瘢痕成纤维细胞胶原合成中的作用

THE EFFECTS OF ACTIVITY OF PROTEIN KINASE A IN TGF-β_1 STIMULATING COLLAGEN SYNTHESIS OF NORMAL SKIN AND HYPERTROPHIC SCAR FIBROBLASTS

目的 :探讨蛋白激酶 A在 TGF- β1 刺激增生性瘢痕和正常人皮肤成纤维细胞 (HS- FB和 NS- FB)合成胶原中的信号转导作用。 方法 :利用 32 P掺入底物法测定TGF- β1 刺激的 HS- FB和 NS- FB的 PKA活性 ,3H-脯氨酸掺入法和放射免疫法测定胶原合成能力。 结果 :NS-FB被 TGF- β1 刺激后 PKA的活性短暂升高后很快恢复 ,HS- FB则在 30～ 6 0 m in降低 (P<0 .0 5 )。TGF- β1 对两种细胞有加速合成胶原的作用 (30 min后 P<0 .0 5 ) ,HS- FB的合成能力比 NS- FB强 (刺激 6 0 min后 P<0 .0 5 )。c AMP有抑制作用 (6 0 min后 P<0 .0 5 ) ,H7则有拟 TGF- β1 作用(与对照比较时 30 min后 P<0 .0 5 ) ,而 H7可增强 TGF- β1刺激的作用 (30～ 6 0 min时 P<0 .0 5 )。 结论 :TGF- β1 刺激两种细胞后 PKA的活性变化提示 c AMP/ PKA通道参与介导 TGF- β1 信号 :TGF- β1 对 HS- FB的短期刺激作用与PKA活性降低有关 ,但长期刺激作用与 PKA通道活性变化无关 ;c AMP/ PKA活化可以抑制 FB合成胶原。

Objective:To investigate the effects of protein kinase A(PKA)in TGF-β 1 stimulating collagen synthesis of normal skin and hypertrophic scar fibroblast(NS-FB and HS-FB). Methods:The activity of PKA of HS-FB and NS-FB was detected by 32 P incorporation assay.Total collagen synthesis was measured by 3 H-proline incorporation assay and radioimmunoassay. Results:The activity of PKA of NS-FB rose temporarily insigmificantly and recovered soon while the ones of HS-FB decreased and recovered at lh the stimulation of TGF-β 1(P<0 05).TGF-β 1 could enhance collagen synthesis of FB(P<0 05 at stimulating 30 minutes later) but the effects were stronger in HS-FB(P<0 05 at stimulating 60 minutes later).cAMP could inhibit the changes (P<0 05 at stimulation 60 minutes) while H 7 could improve roles of TGF-β 1(P<0 05 at 30～60minutes of stimulation). Conclusion:The changes of the PKA activity of the two types of cell after the stimulation of TGF-β 1 might implicate that there was difference in the PKA signal pathway.The effects of TGF-β 1 stimulating collagen synthesis might have partly relation to cAMP/PKA pathway but activating cAMP/PKA signal pathway could abrogate FB to synthesize collagen. [