Lycium barbarum polysaccharide alleviates IL-1ß-evoked chondrogenic ATDC5 cell inflammatory injury through mediation of microRNA-124.

Background: Lycium barbarum polysaccharide (LBP) is a promising therapeutic drug in inflammation-related injuries, nevertheless the mechanism of LBP's action is still elusive. The study is to explore the effect of LBP on IL-1ß-evoked ATDC5 cell inflammatory injury. Methods: ATDC5 cells were administrated with 10 ng/mL interleukin (IL)-1ß to establish an in vitro model of cartilage damage. After management, cell viability was tested through CCK8 assay. The pro-inflammatory cytokines and cyclooxygenase (Cox)-2 were assessed through ELISA, western blot and qRT-PCR. MiR-124 expression in ATDC5 cells was silenced by transfecting with miR-124 inhibitor, and the pro-inflammatory cytokines and Cox-2 were re-assessed. NF-κB and JNK pathways were measured through western blot. Results: IL-1ß stimulation accelerated the release of IL-1ß, IL-6 and TNF-α, elevated Cox-2 expression. LBP significantly eased IL-1ß-induced inflammation. MiR-124 expression was observed to enhance by LBP, and the impacts of LBP on ATDC5 cells were lightened via transfection with miR-124 inhibitor. NF-κB and JNK pathways were activated after IL-1ß stimulation, nevertheless were inactivated by LBP administration. Besides, LBP-evoked the repression of NF-κB and JNK pathways were overturned by miR-124 inhibitor. Conclusions: Our study suggests that LBP protects ATDC5 cells from IL-1ß-evoked injury through up-regulating miR-124 via blocking NF-κB and JNK pathways.

Long non-coding RNA Mirt2 relieves lipopolysaccharide-induced injury in PC12 cells by suppressing miR-429.

Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) play important roles in the pathogenesis of spinal cord injury (SCI). This study investigated the effects of lncRNA Mirt2 and miR-429 on lipopolysaccharide (LPS)-induced injuries in PC12 cells. Serum samples were collected from 36 patients with SCI and the healthy controls. The expression of lncRNA Mirt2 in serum samples was measured by qRT-PCR. The in vitro model of SCI was established by treating PC12 cells with LPS. The effects of lncRNA Mirt2 and miR-429 on the cell model were evaluated by CCK-8 assay, flow cytometry, western blot, qRT-PCR, and ELISA. Further, the activation of NF-κB and p38MAPK pathways was tested by western blot. LPS induced obvious cell injuries in PC12 cells, as cell viability was reduced, apoptosis rate was increased, caspase-3 and -9 were cleaved, and the release of TNF-α and IL-6 was induced. lncRNA Mirt2 was up-regulated in LPS-stimulated PC12 cells and serum samples derived from SCI patients. Overexpression of lncRNA Mirt2 protected PC12 cells against LPS-induced injuries. Further studies found that lncRNA Mirt2 acted as the molecular sponge of miR-429 and miR-34a-5p. lncRNA Mirt2 did not protect PC12 cells when miR-429 was overexpressed. Moreover, the inhibitory effects of lncRNA Mirt2 on NF-κB and p38MAPK pathways were abolished when miR-429 was overexpressed. lncRNA Mirt2 exerts protective effects in an in vitro model of SCI by down-regulating miR-429. This study shed light on the treatment of SCI by using the lncRNA-miRNA regulation network.

[Effect of triptolide on allogenic tendon transplantation in repairing tendon defect in chicken].

OBJECTIVE: Triptolide can suppress immunological rejection reaction. To investigate the effect of triptolide on allogenic tendon transplantation in repairing tendon defect in chicken. METHODS: The defect model of the third toes tendon was established in 64 healthy-cleaning male Leghorn chickens (4-month-old, weighing 1.9-2.3 kg), which underwent allogenic tendon transplantation for repairing and were divided into 2 groups randomly (n=32). Triptolide feeding [100 microg/(kg x d)] was given for 3 weeks in the experimental group and normal feeding in the control group. General condition of the chickens was observed after operation. The transplanted tendons were harvested from 4 chickens in each group for gross observation at 1, 2, 3, and 4 weeks after operation; the histological observation was performed at 1 and 3 weeks, and transmission electron microscope observation at 2 and 4 weeks. The blood and tendon were harvested from another 8 chickens in each group for flow cytometry and biomechanical tests respectively at 3 and 6 weeks. RESULTS: All chickens survived to the experiment end. Gross observation: with time extending, hyperemia and edema around transplanted tendon were relieved. Rarefaction adhering zone was seen in experimental group, and pyknotic adhering zone in control group. Histological observation: inflammatory reaction in experimental group was slighter than that in control group at 1 and 3 weeks. Transmission electron microscope observation: at 2 and 4 weeks, fibroblasts had big cell nucleus, more euchromatin, and little heterochromatin in experimental group; however, there were small amount of rough endocytoplasmic reticulums with gentle expanded capsular space in control group, which contained sparse content. Flow cytometry test: at 3 and 6 weeks, peripheral blood contained less CD4+ and CD8+ T lymphocytes in experimental group than in control group, and the ratio of CD4+ to CD8+ T lymphocyte significantly decreased in experimental group when compared with control group (P < 0.05). Biomechanical examination: at 3 and 6 weeks, the maximum tensile strength in experimental group was bigger than that in control group, and tensile adhesion power in experimental group was smaller than that in control group. There were significant differences in the indexes between 2 groups (P < 0.05). CONCLUSION: Triptolide can suppress immunological rejection reaction, strengthen tendon healing strength, and reduce tendon adhesion in allogenic tendon transplantation.