BACKGROUND:Kidney deficiency and blood stasis syndrome are common traditional Chinese medicine syndromes observed in knee osteoarthritis,which serve as fundamental pathogenesis factors.There exists a significant connection between the two.Previous studies have demonstrated that kidney deficiency and blood stasis syndrome effectively contribute to knee joint cartilage degeneration and the progression of knee osteoarthritis.However,the mechanisms underlying the promotion of knee joint cartilage damage remain unclear and require further investigation. OBJECTIVE:To investigate the influence of kidney deficiency and blood stasis syndrome on the progression of knee osteoarthritis in Sprague-Dawley rats. METHODS:Sixteen Sprague-Dawley rats were randomly divided into two groups:a model observation group and a control group,with eight rats in each group.Animal models of kidney deficiency were induced by ovary removal in the model observation group,while the control group was given a sham procedure for ovarian removal.Two months after modeling,both groups underwent modified HULTH surgery to induce knee osteoarthritis.One week after modified HULTH surgery,the model observation group was subcutaneously given adrenaline hydrochloride to make blood stasis models,while the control group was subcutaneously given normal saline.At the 5th week after modified HULTH surgery,blood rheology,coagulation parameters,triiodothyronine,tetraiodothyronine,and estradiol levels were measured.Knee joint X-ray images were taken,and knee joint sections were stained with safranin O-fast green,hematoxylin-eosin,and immunohistochemistry. RESULTS AND CONCLUSION:Compared with the control group,the model observation group exhibited significant increases in whole blood viscosity at low,medium,and high shear rates,as well as increased plasma viscosity.Fibronectin levels in the coagulation parameters were significantly increased,while prothrombin time and activated partial thromboplastin time were significantly decreased.Triiodothyronine,tetraiodothyronine,and estradiol levels were all significantly decreased.Radiographic results showed that the model observation group exhibited more severe degree of knee joint space narrowing and surface roughness,with the appearance of high-density shadows.Hematoxylin-eosin and safranin O-fast green staining demonstrated more severe cartilage damage in the model observation group,with significantly higher OARSI and Mankin scores compared with the control group.Compared with the control group,immunohistochemistry results showed a significant reduction in the expression of extracellular matrix type II collagen and aggrecan protein in the cartilage of the model observation group rats.Moreover,there was a significant increase in the expression of matrix metalloproteinase 13 and aggrecanase 5,which are inflammatory factors.These results indicate that the Sprague-Dawley rat model of knee osteoarthritis with kidney deficiency and blood stasis was successfully established.Kidney deficiency and blood stasis syndrome further aggravate cartilage extracellular matrix degradation and cartilage degeneration by promoting the expression of inflammatory factors,thereby promoting the progression of knee osteoarthritis in rats.

BACKGROUND:The capability of repairing articular cartilage damage is very limited,and tissue engineering technology provides new therapeutic options for repairing damaged cartilage,in which the interaction and induction between chondrocytes,bone marrow mesenchymal stem cells,and synovial mesenchymal stem cells is the basis of autologous healing of cartilage damage. OBJECTIVE:To construct the chondrocyte-bone marrow mesenchymal stem cell-synovial mesenchymal stem cell co-culture system to simulate the in vitro microenvironment of chondrocytes,and to explore the optimal cell inoculation ratio,meanwhile to observe the effects of icariin-containing serum on the proliferation of chondrocytes and the chondrogenic differentiation of stem cells in the system. METHODS:Rat knee chondrocytes,bone marrow mesenchymal stem cells and synovial mesenchymal stem cells were extracted,cultured and identified,and a chondrocyte-bone marrow mesenchymal stem cell-synovial mesenchymal stem cell non-contact co-culture system was constructed according to different cell inoculation ratios.After 72 hours of co-culturing,the chondrocyte proliferative activity and phenotypic ability were observed,and the co-culture system with the best overall effect was selected.New Zealand white rabbits were gavaged with icariin solution(0.25 mg/mL)to prepare icariin-containing serum,and cultured in conventional complete medium(high sugar DMEM culture medium containing 10%fetal bovine serum and 1%double antibody by volume)as the control group,while the experimental group was intervened by adding 10%icariin-containing serum by volume on the basis of above.The proliferative activity of chondrocytes and the expression of collagen type II were tested for the two groups after 24 and 48 hours.The differentiation of bone marrow mesenchymal stem cells and synovial mesenchymal stem cells into chondrocytes in the co-culture system was tested by immunofluorescence staining after 14 days. RESULTS AND CONCLUSION:(1)The three kinds of cells grew normally adherently to the wall in different ratios of co-culture,where chondrocytes showed the best proliferative activity and phenotypic ability in the co-culture system when chondrocytes:bone marrow mesenchymal stem cells:synovial mesenchymal stem cells=2:1:1.(2)Compared with the control group,the proliferative activity and type II collagen expression of chondrocytes in the experimental group were significantly increased after 24 hours(P<0.01),and the two groups still had difference after 48 hours(P<0.05).The two groups showed obvious chondrogenic differentiation of bone marrow mesenchymal stem cells and synovial mesenchymal stem cells after 14 days(P<0.01),and some of the cells appeared round or oval,and the cytoplasmic type II collagen immunofluorescence staining was positive.The fluorescence intensity of the experimental group was significantly higher than that of the control group(P<0.01).(3)The results showed that the chondrocyte-bone marrow mesenchymal stem cell-synovial mesenchymal stem cell co-culture system could be successfully established by the non-contact co-culture method,and the best chondrocyte proliferative activity and phenotypic ability could be obtained when the cell ratio was 2:1:1.Icariin-containing serum had the promoting effect on chondrocyte proliferation,and chondrogenic differentiation of bone marrow mesenchymal stem cells and synovial mesenchymal stem cells in the system.