Sakamoto Nobuyoshi, Sugimura Kazunobu, Kawashima Hidenori, Tsuchida Kenji, Takemoto Yoshiaki, Naganuma Toshihide, Tatsumi Shinji, Nakatani Tatsuya
Department of Urology, Osaka City University Graduate School of Medicine, Asahi-machi, Osaka 545-8585, Japan.
Int J Mol Med. 2005 Jun;15(6):907-11.
Peritoneal fibrosis is a major complication of long-term continuous ambulatory peritoneal dialysis (CAPD) treatment. Transforming growth factor-beta (TGF-beta) has been reported to play an important role in the fibrosis of various tissues by stimulating connective tissue growth factor (CTGF) expression. In order to elucidate the mechanism of CAPD-related peritoneal fibrosis, we studied the influence of high glucose concentrations and inflammatory cytokines on mRNA expressions of TGF-beta and CTGF in cultured human peritoneal mesothelial cells (HPMC). HPMC were isolated from normal omentum and cultured with 0.5 or 1.0% glucose or mannitol for 7 days. TGF-beta1 and CTGF mRNA were quantified by one step real-time reverse transcription-polymerase chain reaction (real-time RT-PCR). TGF-beta1 and CTGF mRNA expression levels were significantly increased (p<0.05) by glucose in a dose-dependent manner, but not by mannitol. The expression levels were correlated between TGF-beta1 and CTGF. Effects of inflammatory cytokines were also examined by adding tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1) or interleukin-6 (IL-6) to the medium at 0.1 ng/ml for 2 days. TGF-beta1 expression tended to be increased by TNF-alpha and IL-6. On the other hand, CTGF expression was significantly decreased (p<0.01) by IL-1 but not changed by TNF-alpha or IL-6. These results suggest that high glucose concentration may play a central role in peritoneal fibrosis. Responses of TGF-beta1 and CTGF to inflammatory cytokines were not necessarily identical, suggesting that CTGF may be a better therapeutic target for peritoneal fibrosis than TGF-beta1.
腹膜纤维化是长期持续性非卧床腹膜透析（CAPD）治疗的主要并发症。据报道，转化生长因子-β（TGF-β）通过刺激结缔组织生长因子（CTGF）的表达，在各种组织的纤维化过程中发挥重要作用。为了阐明与CAPD相关的腹膜纤维化机制，我们研究了高糖浓度和炎性细胞因子对培养的人腹膜间皮细胞（HPMC）中TGF-β和CTGF mRNA表达的影响。从正常大网膜中分离出HPMC，并分别用0.5%或1.0%的葡萄糖或甘露醇培养7天。通过一步实时逆转录聚合酶链反应（实时RT-PCR）对TGF-β1和CTGF mRNA进行定量分析。葡萄糖以剂量依赖的方式显著增加（p<0.05）TGF-β1和CTGF mRNA的表达水平，但甘露醇则无此作用。TGF-β1和CTGF的表达水平呈正相关。还通过在培养基中添加0.1 ng/ml的肿瘤坏死因子-α（TNF-α）、白细胞介素-1（IL-1）或白细胞介素-6（IL-6）2天来检测炎性细胞因子的作用。TNF-α和IL-6使TGF-β1的表达有增加趋势。另一方面，IL-1使CTGF的表达显著降低（p<0.01），而TNF-α或IL-6对其无影响。这些结果表明，高糖浓度可能在腹膜纤维化中起核心作用。TGF-β1和CTGF对炎性细胞因子的反应不一定相同，这表明CTGF可能比TGF-β1更适合作为腹膜纤维化的治疗靶点。
