Effect of astragalus polysaccharides on expression of MMP2 and MMP9 in annulus fibrosus of cervical intervertebral discs from cervical spondylosis model rats

AIM: To investigate the effect of astragalus polysaccharides (AP) on the expression of matrix metalloproteinase 2 (MMP2) and MMP9 in the annulus fibrosus of cervical intervertebral discs from cervical spondylosis model rats. METHODS: The model rats were randomly divided into model group (M group), and low-dose and high-dose AP treatment groups (L-AP and H-AP groups). The rats in sham operation group were used as negative control group (NC group). In addition, all the annulus fibrosus tissues were used for primary cell culture. Histological analysis was performed using HE staining and Safranin O staining. The expression of MMP2, MMP9, tissue inhibitor of metalloproteinase 2 (TIMP2) and collagen Ⅳ at mRNA and protein levels was analyzed by immunohistochemistry, Western blot and RT-qPCR. Cell-collagen adhesion assay was used to detect annulus fibrosus cell-collagen adhesion. RESULTS: The intervertebral discs of M group were degenerated, while astragalus polysaccharide improved the degenerative disc disease in the rats with cervical spondylosis. Compared with NC group, the expression of MMP2 and MMP9 in the annulus fibrosus tissues of M group increased significantly, while the expression of TIMP2 and collagen Ⅳ was decreased significantly (P<0.05). Compared with M group, the expression of MMP2 and MMP9 in L-AP group and H-AP group was significantly decreased, while the expression of TIMP2 and collagen Ⅳ was significantly increased (P<0.05). The cell-collagen adhesion in M group was significantly lower than that in NC group (P<0.05). Compared with M group, the cell-collagen adhesion in L-AP group and H-AP group was increased significantly (P<0.05). Compared with NC group, the expression of MMP2 and MMP9 in annulus fibrosus cells of M group was increased significantly, while the expression of TIMP2 and collagen Ⅳ was decreased significantly (P<0.05). Compared with M group, the expression levels of MMP2 and MMP9 in L-AP group and H-AP group of fibrocytes were significantly decreased, while the expression of TIMP2 and collagen Ⅳ was significantly increased (P<0.05). CONCLUSION: Astragalus polysaccharides inhibit the expression of MMP2 and MMP9 in the annulus fibrosus of cervical intervertebral discs from cervical spondylosis model rats and regulate the dynamic balance of MMPs and TIMPs in the extracellular matrix, thus inhibiting the degradation of collagen in the intervertebral disc matrix and having the potential research value for the treatment of intervertebral disc degeneration.     

几种前处理方法所获刀鲚(Coilia nasus)耳石年轮的效果比较

本研究较为系统地比较了刀鲚(Coilia nasus)耳石的几种碾磨方法及耳石酸蚀前处理所获刀鲚耳石年轮的效果.结果显示,耳石横截面碾磨法更易获取较为清晰的年轮,而矢状面碾磨法的效果不及前者,但后者在用于耳石微化学的研究中却更有优势.经5％EDTA处理过的耳石,比用1％HC1处理过的耳石,更容易获得较好的年轮效果.本研究还发现,刀鲚耳石年轮形成过程中的一些形态变化,与刀鲚生活史中的生境变化有关联性.     

Echocardiographic measurement of the mitral valve in normal Cavalier King Charles spaniels: repeatability,optimal future study methods,and preliminary reference intervals

Introduction/ObjectivesCavalier King Charles spaniels (CKCS) are ideal candidates for longitudinal study of myxomatous mitral valve (MV) disease and stage B1 clinical trials; however, the optimization of MV measurement acquisition and repeatability must be better defined to realize this potential. Additionally, breed-specific reference ranges for CKCS MV measurements are lacking. Study objectives were to assess measurement repeatability and define optimal methods for the longitudinal study of echocardiographic MV anatomy and to define preliminary, two-dimensional echocardiographic reference ranges for MV measurements in CKCS.AnimalsForty CKCS between 10 and 24 months old.Materials and methodsPre- and post-sedation two-dimensional echocardiographic images optimized for the MV were obtained. The length, width, and area of the anterior and posterior leaflets and the diameter of the MV annulus at end-diastole and end-systole were measured. Measurement repeatability was assessed using % coefficient of variation and repeatability coefficients.ResultsIntraoperator repeatability was best for the operator with previous MV measurement experience, with comparable results for the experienced operator measuring the second operator's images, mimicking a core echocardiography laboratory setting. Except for MV annulus diameter at end-systole, sedation had no significant effect on any MV measurements, nor did it impact measurement repeatability. Preliminary, breed-specific reference ranges were defined for the population, with CKCS often noted to have a larger annular diameter at end-systole than end-diastole.ConclusionsOptimal methods for longitudinal study of the MV in CKCS have been proposed, as have two-dimensional preliminary echocardiographic reference ranges for CKCS MV measurements. The MV annulus in CKCS may differ from other breeds.