Department of Genetics and Molecular Biology, Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi, PR China.
Osteoarthritis Cartilage. 2011 Oct;19(10):1237-45. doi: 10.1016/j.joca.2011.07.002. Epub 2011 Jul 22.
Expression profiles of microRNAs (miRNAs) can shape the repertoire of proteins expressed in development, differentiation and diseases. This study aimed to identify miRNA profile of articular cartilage at different developmental stages in rats.
Three small RNA libraries were constructed from the femoral head cartilage of Sprague-Dawley (SD) rats at postnatal day 0, day 21 and day 42 and sequenced by a deep sequencing approach. Then a bioinformatics approach was employed to distinguish genuine miRNAs from small RNAs represented in the mass sequencing data. The expression of indicated miRNAs was determined by stem-loop RT-qPCR to valuate the consistency with Solexa sequencing.
Two hundred and fifty-eight of 310 known miRNA and miRNA* genes were organized into 91 compact clusters. Two hundred and forty-six miRNAs were detected in all three small RNA libraries of rat articular cartilage. Forty-six, fifty-two and fifty-six miRNA* genes were identified from three small RNA libraries, respectively, and 86 novel miRNA candidate genes were found simultaneously. In addition, 23 known miRNAs were up-regulated (fold change ≥ 4); six were down-regulated (fold change ≤ -4) during articular cartilage development. The predicted targets of differentially expressed miRNAs were locally secreted factors and transcription factors that regulate proliferation and differentiation of chondrocytes. The same expression tendency of indicated miRNAs during articular cartilage development stages was observed by using Solexa sequencing and stem-loop RT-qPCR.
Our study provided a unique opportunity to decipher how the elaboration of the miRNA repertoire contributes to the development process of articular cartilage.
microRNAs（miRNAs）的表达谱可以塑造发育、分化和疾病过程中表达的蛋白质谱。本研究旨在鉴定不同发育阶段大鼠关节软骨的 miRNA 谱。
从小鼠的股骨头软骨构建了三个小 RNA 文库，取自出生后第 0、21 和 42 天，通过深度测序方法进行测序。然后采用生物信息学方法从大规模测序数据中区分真实的 miRNA 和小 RNA。通过茎环 RT-qPCR 测定所指示的 miRNA 的表达，以评估与 Solexa 测序的一致性。
310 个已知 miRNA 和 miRNA基因中的 258 个被组织成 91 个紧凑簇。246 个 miRNA 在大鼠关节软骨的三个小 RNA 文库中均被检测到。三个小 RNA 文库分别鉴定出 46、52 和 56 个 miRNA基因，同时发现了 86 个新的 miRNA 候选基因。此外，在关节软骨发育过程中有 23 个已知 miRNA 上调（倍数变化≥4）；六个下调（倍数变化≤-4）。差异表达 miRNA 的预测靶标是局部分泌因子和转录因子，可调节软骨细胞的增殖和分化。使用 Solexa 测序和茎环 RT-qPCR 观察到指示的 miRNA 在关节软骨发育阶段具有相同的表达趋势。
我们的研究为阐明 miRNA 谱的细化如何促进关节软骨的发育过程提供了独特的机会。
