Serviço de Gastroenterologia & Laboratório Multidisciplinar de Pesquisa, Department of Internal Medicine, Hospital Universitário, Universidade Federal do Rio de Janeiro, Rua Prof. Rodolpho Paulo Rocco 255, Ilha do Fundão, Rio de Janeiro, RJ, 21941-913, Brazil.
Laboratório de Imunologia Celular, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil.
Clin Exp Med. 2017 Aug;17(3):351-369. doi: 10.1007/s10238-016-0434-1. Epub 2016 Sep 21.
Hedgehog (Hh) signaling is essential for intestinal homeostasis and has been associated with inflammation and tissue repair. We hypothesized that Hh signaling could affect the inflammatory process in inflammatory bowel disease (IBD). For this purpose, colon specimens from the inflamed and non-inflamed mucosa of 15 patients with Crohn's disease (CD), 15 with ulcerative colitis, and 15 controls were analyzed by immunohistochemistry and real-time PCR. The production and modulation of cytokines were measured by ELISA from culture explants. Apoptosis was assessed by TUNEL and caspase-3 activity assays. Chemotaxis was evaluated using a transwell system. Primary human intestinal and skin fibroblasts were used for analyzing migration and BrdU incorporation. Hh proteins were generally expressed at the superficial epithelium, and a marked reduction was observed in CD. In the lamina propria, Gli-1 predominantly co-localized with vimentin- and alpha-smooth muscle actin-positive cells, with lower levels observed in CD. In colon explants, Hh stimulation resulted in reduction, while blockade increased, TNF α, IL-17, and TGF β levels. Apoptotic rates were higher in inflamed samples, and they increased after Hh blockade. Levels of Gli-1 mRNA were negatively correlated with caspase-3 activity. Hh blockade increased chemoattraction of monocytes. Primary fibroblasts incorporated more BrdU, but migrated less after Hh blockade. These results suggest that Hh signaling provides a negative feedback to the lamina propria, down-regulating inflammatory cytokines, and inhibiting leukocyte migration and fibroblast proliferation, while favoring fibroblast migration. Therefore, Hh signaling is strongly implicated in the pathogenesis of intestinal inflammation, and it may represent a novel therapeutic target for IBD.
Hedgehog (Hh) 信号对于肠道内稳态至关重要，并且与炎症和组织修复有关。我们假设 Hh 信号可能会影响炎症性肠病 (IBD) 中的炎症过程。为此，通过免疫组织化学和实时 PCR 分析了 15 例克罗恩病 (CD)、15 例溃疡性结肠炎和 15 例对照患者的炎症和非炎症黏膜的结肠标本。通过 ELISA 从培养外植体测量细胞因子的产生和调节。通过 TUNEL 和 caspase-3 活性测定评估细胞凋亡。通过 Transwell 系统评估趋化性。使用原代人肠和皮肤成纤维细胞分析迁移和 BrdU 掺入。Hh 蛋白通常在表面上皮表达，在 CD 中观察到明显减少。在固有层中，Gli-1 主要与波形蛋白和α平滑肌肌动蛋白阳性细胞共定位，在 CD 中观察到较低水平。在结肠外植体中，Hh 刺激导致 TNFα、IL-17 和 TGFβ 水平降低，而阻断则增加。在炎症样本中凋亡率更高，阻断 Hh 后增加。Gli-1 mRNA 水平与 caspase-3 活性呈负相关。Hh 阻断增加单核细胞的趋化性。原代成纤维细胞掺入更多的 BrdU，但阻断 Hh 后迁移减少。这些结果表明，Hh 信号为固有层提供负反馈，下调炎症细胞因子，并抑制白细胞迁移和成纤维细胞增殖，同时促进成纤维细胞迁移。因此，Hh 信号强烈参与肠道炎症的发病机制，可能成为 IBD 的新治疗靶点。
