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Background Osteoarthritis (OA) is a joint disease characterized via destruction of cartilage. Chondrocyte damage is associated with cartilage destruction during OA. Long noncoding RNAs (lncRNAs) are implicated in the regulation of chondrocyte damage in OA progression. This study aims to investigate the role and underlying mechanism of lncRNA homeobox antisense intergenic RNA (HOTAIR) in OA chondrocyte injury. Methods Twenty-three OA patients and healthy controls without OA were recruited. Chondrocytes were isolated from OA cartilage tissues. HOTAIR, microRNA-107 (miR-107) and C-X-C motif chemokine ligand 12 (CXCL12) levels were measured by quantitative real-time polymerase chain reaction and western blot. Cell proliferation, apoptosis and extracellular matrix (ECM) degradation were measured using cell counting kit-8, flow cytometry and western blot. The target interaction was explored by bioinformatics, luciferase reporter and RNA immunoprecipitation assays. Results HOTAIR expression was enhanced, and miR-107 level was reduced in OA cartilage samples. HOTAIR overexpression inhibited cell proliferation, but induced cell apoptosis and ECM degradation in chondrocytes. HOTAIR knockdown caused an opposite effect. MiR-107 was sponged and inhibited via HOTAIR, and knockdown of miR-107 mitigated the effect of HOTAIR silence on chondrocyte injury. CXCL12 was targeted by miR-107. CXCL12 overexpression attenuated the roles of miR-107 overexpression or HOTAIR knockdown in the proliferation, apoptosis and ECM degradation. CXCL12 expression was decreased by HOTAIR silence, and restored by knockdown of miR-107. Conclusion HOTAIR knockdown promoted chondrocyte proliferation, but inhibited cell apoptosis and ECM degradation in OA chondrocytes by regulating the miR-107/CXCL12 axis.

Establish a green development index system for counties (districts) in the Yangtze River Economic Belt of Hubei Province, explore the calculation method of green development level, and compare the green development level differences of 48 county-level districts in the Hubei Yangtze River Economic Belt to conclude: 1) The levels of green development in the cities and towns of the Yangtze River Economic Belt in Hubei Province are uneven and the polarization is serious; 2) Hubei Yangtze River Economic Belt has formed growth poles clustered by green development in Yichang, Wuhan and Huangshi; analyze the factors affecting the city’s green development index: the pros and cons of natural geographical conditions, the degree of convenient transportation, the size of the population density, and the reasonable industrial structure have a positive impact on the city’s green development index.

To study the effect of the repair of rabbit articular cartilage defects by the composite of chondrogenic induction of autologous MSCs and autologous "two-phase" bone matrix gelatin (BMG).Twenty-four healthy adult New Zealand rabbits weighing 2 to 3 kg were divided into group A, B and C with 8 in each. Autologous MSCs derived from group A were cultured in vitro and observed under inverted phase contrast microscope when enough cells through trypsinization transferring in vitro were obtained. Then the growth curves of 1, 3 and 5 passage culture of MSCs were drawn. The 3rd passage MSCs were induced into chondrogenic differentiation by adding TGF-beta1 (10 ng/mL), IGF-1 (10 ng/mL) and vitamin C (50 ng/mL) in vitro. At 8 days after induction, the features of chondrocytes were observed under inverted phase contrast microscope,and immunohistochemical staining and Mallory staining were made. Getting out part of the ilium of group A and B, according to the method of Urist, the "two-phase" BMG was acquired. Chondrogenic induction of autologous MSCs was inoculated into the corresponding BMG to set up a composite of cell-carrier, and then it was observed through scanning electric microscope after 3 days of culture. The model of articular cartilage defects of rabbits was made: in group A,autologous cell-carriers were implanted; in group B, there only existed autologous BMG; in group C,there was nothing. At 8, 12 weeks after operation, the gross, HE staining and immunohistochemical staining were made,and grading scales were evaluated according to Wakitani histological grading method.Features of MSCs were as follows: the shape of primary cells was shot-spindled and of passage cells was long. As to the growth curves of 1, 3 and 5 passage culture of MSCs,passage cells grew slowly for 3 days after being passaged and went into log-growth during the 3rd and the 7th days and into plateau later, but the 3rd passage cells grew best. Observation of MSCs after chondrogenic induction was performed: the shape of cells was elliptical and the effect of induction was verified by the positive results of collagen type II, S-100 and Mallory staining. Under scanning electric microscope,the structure of BMG was good and cells were observed growing in it well. As far as repair of articular cartilage defects are concerned at 8, 12 weeks after transplantation, the defects in group A were repaired by the hyline-like tissue and the structures of the cartilage surface and normal cartilage were in integrity,and immunohistochemical staining of collagen type II was positive, while those in group B and C were repaired by the fibrous-like tissues and the surfaces were irregular. In Wakitanni histological score, at 8 weeks after operation, group A was (3.50 +/- 1.51) points, group B was (10.00 +/- 1.41) points and group C was (12.00 +/- 0.93) points; at 12 weeks, group A was (1.13 +/- 0.99) points, group B was (8.38+/-1.30) points, and group C was (10.13 +/- 1.64) points. At different time points,group A was significantly better than group B and C, showing significant differences (P0.05).Induced autologous MSCs and the composite withautologous "two-phase" BMG have the function to repair articular cartilage defects, and they are better than autologous BMG transplanted only or nothing transplanted.