De Palma Anna, Cheleschi Sara, Pascarelli Nicola Antonio, Giannotti Stefano, Galeazzi Mauro, Fioravanti Antonella
Department of Medicine, Surgery and Neuroscience, Rheumatology Unit, University of Siena, Policlinico Le Scotte, Viale Bracci 1, 53100 Siena, Italy; Department of Medical Biotechnologies, University of Siena, Policlinico Le Scotte, Viale Bracci 1, 53100 Siena, Italy.
Department of Medicine, Surgery and Neuroscience, Rheumatology Unit, University of Siena, Policlinico Le Scotte, Viale Bracci 1, 53100 Siena, Italy.
J Biomech. 2018 Jan 3;66:165-169. doi: 10.1016/j.jbiomech.2017.10.044. Epub 2017 Nov 7.
Mechanical stimuli and hydrostatic pressure (HP) play an important role in the regulation of chondrocytes metabolism. Growing evidence demonstrated the ability of mechanical loading to modulate the expression of microRNA (miRNA) involved in chondrocytes homeostasis and in the pathogenesis of osteoarthritis (OA). The expression of miR-155, miR-181a and miR-223 in normal and OA chondrocyte cultures, and their potential modifications following exposure to three hours of a cyclic HP (1-5 MPa, frequency 0.25 Hz) were investigated. Also evaluated the expression of Chuk, regulator of the NF-kB pathway activation, which is a target gene of miR-223, was evaluated. Chondrocytes were collected immediately after pressurization (T0), and following 12, 24, and 48 h. Total RNA was extracted, reverse transcribed and used for real-time PCR. At basal condition, a significant increase of miR-155 and miR-181a was observed in OA in comparison to normal cells; on the contrary, no differences in miR-223 and Chuk expression levels were detected between normal and OA chondrocytes. miR-155 and miR-181a resulted significantly downregulated immediately after pressurization (T0) in OA cells. The pressure effect on miR-155 and miR-181a levels was maintained over time. No modifications of miR-223 were observed in response to HP, while Chuk levels resulted significantly reduced at T0 and after 12 h. Pressurization did not cause any modifications in normal cells. In conclusion, HP was able to modulate the expression of miRNA associated to OA pathogenesis. The preliminary results about Chuk response to pressure raised interest in its involvement in the possible HP induced NF-kB pathway modulation.
机械刺激和流体静压（HP）在软骨细胞代谢调节中发挥着重要作用。越来越多的证据表明，机械负荷能够调节参与软骨细胞稳态和骨关节炎（OA）发病机制的微小RNA（miRNA）的表达。研究了正常和OA软骨细胞培养物中miR-155、miR-181a和miR-223的表达，以及在暴露于三小时循环HP（1-5MPa，频率0.25Hz）后它们的潜在变化。还评估了NF-κB途径激活调节剂Chuk的表达，Chuk是miR-223的靶基因。在加压后立即（T0）以及12、24和48小时后收集软骨细胞。提取总RNA，进行逆转录并用于实时PCR。在基础条件下，与正常细胞相比，OA中miR-155和miR-181a显著增加；相反，在正常和OA软骨细胞之间未检测到miR-223和Chuk表达水平的差异。在OA细胞中，加压后立即（T0）miR-155和miR-181a显著下调。随着时间的推移，压力对miR-155和miR-181a水平的影响持续存在。未观察到miR-223对HP的反应有任何变化，而Chuk水平在T0和12小时后显著降低。加压在正常细胞中未引起任何变化。总之，HP能够调节与OA发病机制相关的miRNA的表达。关于Chuk对压力反应的初步结果引发了人们对其参与可能的HP诱导的NF-κB途径调节的兴趣。
