Effect Of Macrophage-specific Nfe2l1 Deficiency On The Occurrence And Development Of Osteoarthritis And Its Related Mechanisms

Object: Osteoarthritis is a common disabling disease.With the aging of the population and the increasing rate of obesity,the incidence of osteoarthritis is getting higher and higher,which not only brings many inconveniences to the production and life of patients,but also because it is difficult to cure.The reason has also become a social burden.Epidemiological investigations show that the knee joint is the most common part of osteoarthritis,and the prevalence of knee joints is greater in the elderly than in the young and middle-aged,and in women than in men.Because the structure of the knee joint is complex,it is often accompanied by pathological changes in multiple surrounding tissues when osteoarthritis occurs.Laboratory research results show that its complex pathogenesis involves mechanical,inflammatory and metabolic factors,under the combined action of multiple factors,Eventually leading to inflammation of the synovial membrane of the patient’s joints and structural destruction of articular cartilage and subchondral bone.In recent years,the role of joint synovial inflammation in aggravating the overall course of knee osteoarthritis has been valued by more and more researchers,and the results of previous studies in our laboratory have shown that the long Nfe2l1 specifically knocked out RAW264.7cell line In the RAW264.7 cell line,the expression of multiple genes related to M1 polarization increased,which can prove that the loss of Nfe2l1 in the RAW264.7 cell line is closely related to the inflammatory response.Based on the above research status,this study used C57BL/6 myeloid cell Nfe2l1 specifically knocked out old mice and their control group to establish an old mouse osteoarthritis model,and used Nfe2l1 overexpressing RAW264.7 cell line to explore the effects of Nfe2l1 The molecular mechanism in the development of osteoarthritis.Method:1.Using C57BL/6 myeloid cell Nfe2l1 specifically knocked out old mice and their control group to establish an elderly spontaneous Osteoarthritis model;2.Collect basic information such as weight,body composition and metabolic cage indicators of mice,and preliminarily judge whether old mice have Osteoarthritis through gait analysis and the appearance of mice paws;3.Score the degree of Osteoarthritis in mice by staining pathological sections with Safranin Fast Green and Toluidine Blue;4.Use Nfe2l1 specific knockout mouse bone marrow primary cells,Nfe2l1 specific silencing and overexpression of each subtype of the RAW264.7 cell line for single-cell sequencing,RNA-seq and Ch IP-seq experiments,from a molecular perspective Explain the mechanism of Osteoarthritis.Result:1.Compared with the control group,there were no significant differences in the body weight,body composition and metabolic cage respiratory volume of elderly spontaneous Osteoarthritis mice specifically knocked out by Nfe2l1.Compared with the control group,there was no significant difference in blood pressure,fasting body weight,and blood sugar in elderly spontaneous Osteoarthritis mice specifically knocked out by Nfe2l1.Compared with the control group,there was no significant difference in the activity and activity level of the elderly spontaneous Osteoarthritis mice with specific knockout of Nfe2l1;the results of gait analysis showed that compared with the control group,the specific knockout of Nfe2l1 was The shorter standing time of old female mice proved that the mice had Osteoarthritis painful gait,and preliminary proof that the mice with specific knockout of Nfe2l1 had a tendency for Osteoarthritis.Among several groups of mice in the same litter,the paws of the mice in the KO group tend to be more red and swollen.This red and swollen appearance preliminarily proves that the mice in the KO group are more Osteoarthritis prone.The results of Safranin and Fast Green staining and toluidine blue staining showed that compared with the control group,the mice in the experimental group lost cartilage matrix,the number of chondrocytes decreased,and the calcified cartilage invaded hyaline cartilage,which proved that the mice in the KO group were better than those in the control group,Osteoarthritis is more serious.2.The results of single-cell sequencing and RNA-seq show that Nfe2l1 is closely related to the occurrence and development of Osteoarthritis.The results of Ch IP-seq show that Nfe2l1 may affect Osteoarthritis by directly regulating the expression of Il6.Conclusion:1.Older mice with myeloid monocyte-specific Nfe2l1 knockout are more susceptible to Osteoarthritis.2.Nfe2l1 is related to JAK-STAT,NF-κB and other signal pathways related to Osteoarthritis.3.The effect of myeloid monocyte-specific Nfe2l1 deletion on the occurrence and development of Osteoarthritis may be because Nfe2l1 can directly regulate the expression of Il6,so when Nfe2l1 is deleted,mice suffer from Osteoarthritis more severe.