ABSTRACT
BACKGROUND:Swimming is an important non-pharmacological treatment for knee osteoarthritis,which can effectively alleviate the disease.However,the effect and mechanism of swimming on senile knee osteoarthritis are still unclear. OBJECTIVE:To investigate the effect of swimming exercise on the articular cartilage of aged mice with knee osteoarthritis. METHODS:Six 3-month-old male C57BL/6 mice were selected as the young group,and twelve 18-month-old male C57BL/6 mice were randomized into the aged group and the swimming group,with six mice in each group.Mice in the swimming group received adaptive swimming for 1 week and formal swimming for 8 weeks.After the intervention,stride length analysis and sampling were performed in each group.The total number of leukocytes and lymphocytes in peripheral blood was detected by blood routine examinations.The morphology of the articular cartilage was observed by hematoxylin-eosin and safranin O-fast green staining.Chondrocyte counts and the modified Mankin's score were used to evaluate the degree of articular cartilage damage.The protein and mRNA expressions of type Ⅱ collagen,aggrecan and matrix metalloproteinase 13 in articular cartilage were detected by immunohistochemical staining and RT-qPCR. RESULTS AND CONCLUSION:Compared with the young group,the mice in the aged group showed significantly decreased stride length(P＜0.05),significantly increased numbers of peripheral leukocytes and lymphocytes(P＜0.05),significantly decreased count of chondrocytes(P＜0.05),significantly increased modified Mankin's score(P＜0.05),significantly decreased protein and mRNA expression of type Ⅱ collagen and aggreca(P＜0.05),and significantly increased matrix metalloproteinase 13 expression(P＜0.05).Moreover,hematoxylin-eosin and safranin O-fast green staining showed the uneven surface of the articular cartilage,abnormal chondrocytes,and proteoglycan loss in the aged group.Compared with the aged group,swimming exercise significantly improved the stride length of mice(P＜0.05),decreased the count of peripheral blood lymphocytes(P＜0.05),increased the count of chondrocytes(P＜0.05),decreased the modified Mankin's score(P＜0.05),increased the protein and mRNA expression of type Ⅱ collagen and aggrecan(P＜0.05),and decreased the expression of matrix metalloproteinase 13(P＜0.05).Hematoxylin-eosin and safranin O-fast green staining showed that the articular surface of mice in the swimming group was smooth,chondrocytes were normal,and proteoglycan loss was less.All these findings indicate that swimming exercise can reduce the number of inflammatory cells in the blood of aged mice,improve articular chondrocytes,matrix composition and cartilage tissue morphology;thus,it has a protective effect on the cartilage of aged mice with knee osteoarthritis.
ABSTRACT
Laboratory animals are an important part of life sciences and medical researches, as well an important support for the science and technology innovation in our country. Laboratory animal science is of great significance to the protection of human health,food safety and biological safety. Laboratory animals are indispensable in the development of food safety,drugs,vaccines and biological products and the studies of human disease pathogenesis. In order to adapt to the requirements for overall development of the laboratory animal industry in China, our institute has independently developed the Network Training System for Laboratory Animal Managers. This system is an online education and training platform which integrates the practical operation and theoretical knowledge of laboratory animals,including seven knowledge modules such as animal welfare,animal breeding,animal surgery and so on. The training subjects of the system include managers, experiment operators, laboratory animal doctors and breeders, aimed at accelerating the personnel training and team building of laboratory animal sciences,and promoting the transformation and development of personnel training in laboratory animal industry.
ABSTRACT
ObjectiveTo investigate the in vivo biological performance of 5 porous bioceramic scaffolds,which were bioglass,β-tricalcium phosphate (β-TCP),hydroxyapatite (HA),β-calcium silicate (β-CS) and α-CS,implanted in rabbit dorsal muscle.MethodsThe 5 porous bioceramic scaffolds were fabricated by adding pore-forming materials and sintering,and then were investigated by X-ray diffraction,porosity mensuration and biomechanics test.The scaffolds were implanted into rabbit dorsal muscle for 4,8,12,16 weeks,respectively.The samples were analyzed by X-ray,Micro-CT,histological analysis,scanning electron microscope (SEM) and energy dispersive spectrometer (EDS).The expression of bone morphogenetic protein(BMP-2) and BMP-7 in the muscle in touch with bioceramic scaffolds were also investigated by polymerase chain reaction(PCR).ResultsThe characteristic analysis of 5 scaffolds showed that the sequence of compressive strength was bioglass＞α-CS＞β-CS＞β-TCP＞HA,the sequence of elasticity modulus was α-CS＜β-TCP＜HA＜β-CS＜bioglass.It was confirmed by X-ray,Micro-CT and histological analysis that the sequence of biodegradability was β-CS＞α-CS＞β-TCP＞bioglass＞HA.The histological observation showed no new bone formation in five scaffolds.A Ca-P layer was formed in the surface of bioglass,α-CS and β-CS,which suggested their in vivo bioactivity.After 16 weeks,the expression of BMP-2 and BMP-7 was found only in β-CS.Conclusion The porous calcium silicate scaffold,which was promising for bone tissue engineering,was with good in vivo bioactivity and biodegradability,without in vivo osteoinductivity.