College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
Comp Biochem Physiol B Biochem Mol Biol. 2013 Oct;166(2):117-22. doi: 10.1016/j.cbpb.2013.07.010. Epub 2013 Aug 6.
The Indian hedgehog (Ihh) signal plays a vital role in regulating proliferation and hypertrophy of chondrocytes. To investigate its function in postnatal chicken (Gallus gallus) chondrocytes, cyclopamine was used to inhibit Ihh signaling. The MTT and ALP assays revealed the downgrade-proliferation and upgrade-differentiation of chondrocytes. To further elucidate the mechanism, the mRNA expression levels of Ihh, parathyroid hormone related protein (PTHrP), Gli-2, Bcl-2, Bone Morphogenetic Protein 6 (BMP-6), type X collagen (Col X) and type II collagen (Col II) were detected by quantitative real-time RT-PCR analysis, and the protein expressions of Ihh, Col X, and Col II were determined using Western blot analysis. After the Ihh signal was blocked, chondrocytes demonstrated high expression levels of PTHrP and Col X and low levels of Gli-2, BMP-6, Bcl-2 and Col II although Ihh expression was increased. Based on these results, the Ihh signal is essential for balancing chicken chondrocyte proliferation and hypertrophy, and the regulatory function of PTHrP acts in an Ihh-dependent manner. Furthermore, BMP-6 and Bcl-2 played roles in maintaining the development of chondrocytes and may be downstream regulatory factors of Ihh signaling.
印度刺猬 (Ihh) 信号在调节软骨细胞的增殖和肥大中起着至关重要的作用。为了研究其在鸡（Gallus gallus）软骨细胞中的作用，使用环巴胺抑制 Ihh 信号。MTT 和 ALP 测定显示软骨细胞增殖能力下降和分化能力增强。为了进一步阐明机制，通过定量实时 RT-PCR 分析检测了 Ihh、甲状旁腺激素相关蛋白 (PTHrP)、Gli-2、Bcl-2、骨形态发生蛋白 6 (BMP-6)、X 型胶原 (Col X) 和 II 型胶原 (Col II) 的 mRNA 表达水平，并通过 Western blot 分析检测了 Ihh、Col X 和 Col II 的蛋白表达。阻断 Ihh 信号后，尽管 Ihh 表达增加，但软骨细胞中 PTHrP 和 Col X 的表达水平较高，而 Gli-2、BMP-6、Bcl-2 和 Col II 的表达水平较低。基于这些结果，Ihh 信号对于平衡鸡软骨细胞的增殖和肥大是必不可少的，而 PTHrP 的调节功能以 Ihh 依赖的方式发挥作用。此外，BMP-6 和 Bcl-2 在维持软骨细胞发育中发挥作用，可能是 Ihh 信号的下游调节因子。
