MicroRNA-149 Suppresses Inflammation in Nucleus Pulposus Cells of Intervertebral Discs by Regulating MyD88.

BACKGROUND Intervertebral disc degeneration (IDD) is associated with low back and neck pain, but the mechanisms underlying its pathogenesis are unclear. In this study, we explored the function of microRNA-149 (miR-149) in inflammatory response mediated by lipopolysaccharide (LPS) in nucleus pulposus (NP) cells. MATERIAL AND METHODS Quantitative real-time PCR was used to detect miRNA and mRNA levels, while Western blotting was utilized to determine protein levels. ELISA was used to examine chemokine production. The correlation between miR-149 and MyD88 was assessed by reporter assay. Apoptosis was examined by flow cytometry. RESULTS miR-149 expression was significantly decreased after LPS exposure in NP cells. Overexpression of miR-149 reversed LPS-induced inhibition in aggrecan and collagen II expression and attenuated LPS-mediated promotion in the levels of MMP3, ADAMTS4, and inflammatory cytokines. Moreover, we found that miR-149 exerted its function by targeting MyD88 in NP cells. CONCLUSIONS miR-149 can inhibit the inflammatory response mediated by LPS in NP cells, and might be a potential target for the treatment of IDD.

Effect of the co-culture of human bone marrow mesenchymal stromal cells with human umbilical vein endothelial cells in vitro.

Mesenchymal stem cells (MSCs) give origin to the marrow tromal environment that supports hematopoiesis. These cells present a wide range of differentiation potentials and a complex relationship with hematopoietic stem cells (HSCs) and endothelial cells. In addition to bone marrow (BM), MSCs can be obtained from other sites in the adult or the fetus. Recent studies have shown that cocultured endothelial cells and osteoblasts are mutually promotive in bone tissues repair. In this study, we observed the effects of coculture of endothelial cells and osteoblasts at different ratios on vasculogenesis and bone formation, and we found that angiogenic effect is more effective when endothelial cells are cocultured with osteoblasts at the ratio of 4:1, and osteogenic effect is more effective at the ratio of 1:4. It is concluded that the co-culture of human bone marrow mesenchymal stromal cells with human umbilical vein endothelial cells could be a promising culture system for bone tissue engineering applications.

[Preliminary investigation of animal model of tibial defection fracture made by drilling hole method ].

OBJECTIVE: To compare the differences in damage degree, healing time and healing process between two animal models of defection fracture and provide the research data for the establishment of a new animal model. METHODS: Sixty male SPF Spragur-Dawley rats were divided randomly into control group, sawing group and drilling hole group, with 20 rats in each group. Animals of drilling hole group were treated with hone drill and made an 1 mm hole on tibial plateau animals of sawing group were treated with saw and made an 3 mm defection on tibial plateau; nothing to do in animals of control group. The rats were respectively killed at 2nd, 4th weeks after operation, bone density, bone ash quantity, contents of bone Ca, P were detected. RESULTS: At the 2nd week after operation, bone density, bone ash quantity, contents of bone Ca, P in drilling hole group and sawing group were significantly lower than that of the control group (P < 0.05 or P < 0.01). Two animal models of drilling hole group and sawing group were similar in X-ray films and pathology investigations. At the 4th week after operation, there were no significant defference in bone density and bone ash quantity among three groups (P > 0.05). Rats of sawing group showed more poroma and inflammatory infiltration in histological examination. CONCLUSION: Drilling hole method and sawing method could be used to make animal model of defection fracture, two methods showed similar damage degree, healing time and healing process, hut drilling hole method have advantages of simple operation, easily control damage degree and less inflammatory infiltration and bone disunion.

Diffusion tensor imaging in the cervical spinal cord.

There are discrepancy between MR findings and clinical presentations. The compressed cervical cord in patients of the spondylotic myelopathy may be normal on conventional MRI when it is at the earlier stage or even if patients had severe symptoms. Therefore, it is necessary to take a developed MR technique--diffusion tensor imaging (DTI)--to detect the intramedullary lesions. Prospective MR and DTI were performed in 53 patients with cervical compressive myelopathy and twenty healthy volunteers. DTI was performed along six non-collinear directions with single-shot spin echo echo-planar imaging (EPI) sequence. Intramedullary apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values were measured in four segments (C2/3, C3/4, C4/5, C5/6) for volunteers, in lesions (or the compressed cord) and normal cord for patients. DTI original images were processed to produce color DTI maps. In the volunteers' group, cervical cord exhibited blue on the color DTI map. FA values between four segments had a significant difference (P < 0.01), with the highest FA value (0.85 ± 0.03) at C2/3 level. However, ADC value between them had no significant difference (P > 0.05). For patients, only 24 cases showed hyperintense on T2-weighted image, while 39 cases shown patchy green signal on color DTI maps. ADC and FA values between lesions or the compressed cord and normal spinal cord of patients had a significant difference (both P < 0.01). FA value at C2/3 cord is the highest of other segments and it gradually decreases towards the caudal direction. Using single-shot spin echo EPI sequence and six non-collinear diffusion directions with b value of 400 s mm(-2), DTI can clearly show the intramedullary microstructure and more lesions than conventional MRI.

The protective effects of incadronate on inflammation and joint destruction in established rat adjuvant arthritis.

The effects of a new generation bisphosphonate, incadronate, in established adjuvant arthritis rats were evaluated according to the arthritis index, hind paw volume, and radiological and histopathological examinations. Incadronate suppressed the radiological and histopathological changes of hind paws, as well as the joint swelling in a dose-dependent manner. In contrast, the arthritis control rats showed drastic joint inflammation, marked destruction of bone and articular cartilage. The remains of articular cartilage lost Safranin O staining, and were attached with numerous TRAP-positive multinuclear cells. Some of resorption lacunas could be seen at the cartilage matrix nearby the TRAP-positive multinuclear cells. As regards the chondroprotective effects of bisphosphonates, we speculate that it is probably concerned with the inhibition of the chondroclasts. These data indicate that bisphosphonates may be a class of effective agent that can be considered for treatment of various arthritic conditions, including human rheumatoid arthritis.

Antiinflammatory and chondroprotective effects of the aminobisphosphonate incadronate (YM175) in adjuvant induced arthritis.

OBJECTIVE: Incadronate is a third-generation bisphosphonate that suppresses bone resorption and is used to treat skeletal disorders and prevent bone loss in pathological conditions. We evaluated its therapeutic potential and antiinflammatory effects in established adjuvant induced arthritis (AIA), a rat model of rheumatoid arthritis (RA). METHODS: Rats were administered incadronate subcutaneously at a dose of either 0.1 or 1.0 mg/kg/day, or 0.1 or 1.0 mg/kg/week, while a positive control group received phosphate buffered saline alone from Day 14 (after the onset of arthritis) to Day 42. The destruction of bone and cartilage and the antiinflammatory effects of incadronate in rats with established AIA were assessed during treatment, with reference to the arthritis index, hind paw volume, and radiological and histological examinations. To establish whether incadronate affects the migration of inflammatory cells, a chemotaxis assay was carried out using macrophage-like RAW 264.7 cells. Results. In vivo, incadronate suppressed the clinical manifestations of AIA in a dose-dependent manner. In vitro, the various concentrations of incadronate suppressed the migration of macrophages, but the viability and adhesion of these cells were not suppressed. CONCLUSION: Incadronate not only inhibits bone destruction but also reduces cartilage degeneration and joint inflammation in rats with established AIA. The mechanism underlying these antiinflammatory actions of incadronate may be attributable to the inhibition of macrophage migration to the site of inflammation. Bisphosphonates might be effective in preventing the progressive joint destruction and inflammation seen in patients with RA.