Objective : To investigate the expression and clinical significance of kynurenine-3-monooxygenase (KMO) in peripheral blood mononuclear cells ( PBMC ) ，synovial tissue ，and fibroblastic-like synovial cells (FLS) of rheumatoid arthritis (RA) patients． Methods : Peripheral blood samples from 25 healthy control ( HC) individuals and 25 patients diagnosed with RA were collected ，and real-time fluorescence quantitative PCR and Western blot were used to detect KMO gene and protein expression in PBMC of RA and HC groups，and to analyze the correlation between the expression level of the KMO gene in the PBMC of the RA patients and the indexes of the laboratory tests．Meanwhile，immunohistochemistry and immunofluorescence were used to detect KMO expression in synovial tissue and FLS in RA and HC groups． Results : ① KMO gene and protein expression in PBMC of RA group were higher than that of HC group，and the difference was statistically significant (P＜0. 001) ．② The level of KMO gene expression in PBMC of RA group was positively correlated with disease activity index 28 score，blood sedimentation，and rheumatoid factor (rs = 0. 417，P = 0. 038 ; r = 0. 545，P = 0. 005 ; rs = 0. 433，P = 0. 031) ， and had no correlation with C-reactive protein and anti-cyclic citrullinated polypeptide antibody．③ KMO expres- sion in synovial tissue of RA group was higher than that of HC group，and the difference was statistically significant (P＜0. 01) ; KMO expression in FLS of synovial tissue of RA group was higher than that of HC group，and the difference was statistically significant (P ＜0. 001) ． Conclusion KMO expression increases in PBMC ，synovial tissue and FLS of RA patients，and the level of KMO gene expression is correlated with the disease activity of RA patients，suggesting that KMO may promote the course of RA．

Objective : To explore the impacts and fundamental mechanisms of the PU. 1 inhibitor DB2313 on the immune function in MRL/lpr mice. Methods: A total of thirty MRL/lpr lupus mice were randomly distributed into three separate groups : the model control group , the PU. 1 inhibitor DB2313 treatment group ( administered at a dose of 17 mg/kg) , and the positive drug control Telitacicept (TACI_Ig) group (administered at a dose of 7. 5 mg/ kg) . Furthermore , a group of ten BALB/c mice were assigned as the normal group. The DB2313 administration group was treated with intraperitoneal injections of the drug on three occasions per week , while the TACI_Ig group received subcutaneous injections every second day; both treatment protocols were maintained for a duration of five weeks. Both the control group and the model group were administered intraperitoneal injections of a volume of saline that was equivalent across groups. After the drug was given , mice were sacrificed by dislocation after orbital vein blood collection. The thymus and spleen were aseptically excised , individually weighed , and subsequently utilized to compute the thymus index and spleen index. The relative distribution of T lymphocyte subsets within the spleen was ascertained through flow cytometry. Serum concentrations of anti_nuclear antibodies ( ANA) and antidouble_stranded DNA antibodies were quantified using an enzyme_linked immunosorbent assay (ELISA) . The levels of inflammatory factors interleukin_6 (IL_6) , tumor necrosis factor_α (TNF_α) , interferon_γ(IFN_γ) were meas ured by CBA method. Hematoxylin and eosin ( HE) staining was employed to examine pathological alterations in the spleen. The expression of PU. 1 and IL_9 in spleen tissue was detected using immunohistochemistry. Additionally , the expression level of PU. 1 protein in the spleen tissue was ascertained through Western blot analysis. Results: The administration of DB2313 significantly ameliorated spleen lesions in MRL/lpr mice and decreased the levels of anti_ds_DNA , ANA , TNF_α , IL_6 , and IFN_γ . It also reduced the proportion of total T cells , TFH cells , Th17 cells , and Th9 cells in the mouse spleen , while increasing the proportion of Treg cells. Furthermore , it lowered the level of PU. 1 protein in the spleen. Immunohistochemistry results demonstrated that DB2313 treatment significantly diminished the expression of PU. 1 and IL_9 in spleen tissue. Conclusion The PU. 1 inhibitor DB2313 can improve spleen lesions in MRL/lpr mice and slow the progression of the disease , and its mechanism is related to the regulation of immune cell functions.

Objective : To establish an interleukin-1β (Il-1β) induced inflammatory model of rat articular chondro- cytes (ACs) , and to investigate the relationship between the expression of lysine acetyltransferase 7 (KAT7) under inflammatory stimulation and the senescence of ACs. Methods: Primary ACs were obtained by digestion of rat knee cartilage with collagenase type Ⅱ and identified. The inflammatory model of ACs was induced by IL-1β . KAT7 was over-expressed or knocked down in ACs by adeno-associated virus infection or small interfering RNA transfection , respectively. A negative control group was set up. Transwell assay was used to detect cell migration ability. Senes- cent cells were stained with senescence-associated β-galactosidase (SA-β-Gal) . Western blot ( WB) was used to detect the protein expression levels of KAT7 , collagen type II (Col Ⅱ ) , matrix metalloproteinase 13 (MMP13) , tumor protein p53 (p53) and cyclin-dependent kinase inhibitor 1A (p21) . The cells of negative control group and KAT7 over-expression group were performed for RNA sequencing , and WB was used to verify the related signaling pathways obtained by Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis. Results: Compared with the control group , the SA-β-Gal staining was enhanced , the protein expression of Col Ⅱ decreased , the pro- tein expression of MMP13 and p53 increased , the cell migration ability decreased , and the expression of KAT7 also increased in the ACs of rats after IL-1β stimulation. Compared with the negative control group , the SA-β-Gal stai- ning was enhanced , the protein expression of Col Ⅱ decreased , the protein expression of MMP13 , p53 and p21 in- creased , and the cell migration ability decreased in the KAT7 over-expression group. Compared with the negative control group , the SA-β-Gal staining was weakened , the protein expression of Col Ⅱ increased , the protein expres- sion of MMP13 , p53 and p21 decreased , and the cell migration ability was enhanced in the KAT7 knockdown inflammatory model of ACs. KEGG enrichment analysis showed that phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway was activated. Compared with the negative control group , the relative protein ex⁃pression levels of phosphorylated protein kinase B (p⁃AKT)/AKT and phosphorylated mammalian target of rapamy⁃cin (p⁃mTOR)/mTOR in KAT7 over⁃expression group increased. The relative protein expression levels of p ⁃AKT/AKT and p ⁃mTOR/mTOR in KAT7 knockdown cells decreased. Conclusion Rat ACs with high expression of KAT7 exhibit senescence and osteoarthritis phenotype , and the mechanism may be related to the activation of PI3K/AKT/mTOR signaling pathway by KAT7.

Objective To explore the impacts and fundamental mechanisms of the PU.1 inhibitor DB2313 on the immune function in MRL/lpr mice.Methods A total of thirty MRL/lpr lupus mice were randomly distributed into three separate groups:the model control group,the PU.1 inhibitor DB2313 treatment group(administered at a dose of 17 mg/kg),and the positive drug control Telitacicept(TACI-Ig)group(administered at a dose of 7.5 mg/kg).Furthermore,a group of ten BALB/c mice were assigned as the normal group.The DB2313 administration group was treated with intraperitoneal injections of the drug on three occasions per week,while the TACI-Ig group received subcutaneous injections every second day;both treatment protocols were maintained for a duration of five weeks.Both the control group and the model group were administered intraperitoneal injections of a volume of sa-line that was equivalent across groups.After the drug was given,mice were sacrificed by dislocation after orbital vein blood collection.The thymus and spleen were aseptically excised,individually weighed,and subsequently uti-lized to compute the thymus index and spleen index.The relative distribution of T lymphocyte subsets within the spleen was ascertained through flow cytometry.Serum concentrations of anti-nuclear antibodies(ANA)and anti-double-stranded DNA antibodies were quantified using an enzyme-linked immunosorbent assay(ELISA).The lev-els of inflammatory factors interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),interferon-γ(IFN-γ)were meas-ured by CBA method.Hematoxylin and eosin(HE)staining was employed to examine pathological alterations in the spleen.The expression of PU.1 and IL-9 in spleen tissue was detected using immunohistochemistry.Addition-ally,the expression level of PU.1 protein in the spleen tissue was ascertained through Western blot analysis.Re-sults The administration of DB2313 significantly ameliorated spleen lesions in MRL/lpr mice and decreased the levels of anti-ds-DNA,ANA,TNF-α,IL-6,and IFN-γ.It also reduced the proportion of total T cells,TFH cells,Th17 cells,and Th9 cells in the mouse spleen,while increasing the proportion of Treg cells.Furthermore,it low-ered the level of PU.1 protein in the spleen.Immunohistochemistry results demonstrated that DB2313 treatment sig-nificantly diminished the expression of PU.1 and IL-9 in spleen tissue.Conclusion The PU.1 inhibitor DB2313 can improve spleen lesions in MRL/lpr mice and slow the progression of the disease,and its mechanism is related to the regulation of immune cell functions.

Objective To investigate the role of KAT7 in cartilage cell and tissue ageing by establishing an over-replicating-induced primary mouse cartilage cell ageing model and a mouse natural ageing model.Methods Chon-drocytes of the mouse knee joint were obtained by type Ⅱ collagenase digestion and identified by toluidine blue stai-ning and Col Ⅱ staining.The age-related proteins and KAT7 expression levels in cartilage cells from different gener-ations of mice were discovered using Western blot and cellular immunofluorescence techniques,and the aging of the cells was assessed by SA-β-Gal coloring.The pathological alterations were examined in the joints of 22-month-old mice compared to 2-month-old mice using HE staining and safranin O-solid green staining.Additionally,immuno-histochemical analysis was done to observe the expression of KAT7 and p53 in mouse joint tissue.Results Com-pared with the control group,the expression levels of KAT7 protein and p21 and p53 in aged mouse chondrocytes significantly increased.WM-3835,a commonly inhibitor of KAT7 that possess the capacity on halting the protein expression procedure of gene KAT7 as well as p21 in ageing chondrocytes.SA-β-Gal staining showed a significant increase in positive staining of chondrocytes in the eighth generation(P8)compared to the first generation(P1).Compared with the cartilage tissue of young mice,the cartilage tissue of elderly mice presents a near-bone distribu-tion,with a decrease in cartilage surface integrity,a significant increase in the number of hypertrophic chondro-cytes,and more KAT7 and p53 cells that were positive.Conclusion The expression of KAT7 increases in the ageing chondrocytes and the cartilage tissue of ageing mice,reveales the potential significance of KAT7 correlated to cellular aging process in cartilage.

Objective To examine the impact and partial mechanism of bupivacaine sustained-release drug(code PB21)in combination with low-dose dexamethasone(Dex)on the analgesic time of rats with knee osteoarthritis(KOA).Methods Using the techniques of anterior cruciate ligament transection and meniscus instability,a rat KOA model was created.After eight weeks,SD mice were split into three groups at random:a group for the model,one for Dex(50 μg),one for PB21(1.5 mg),and one for combined administration(1.5 mg PB21/50 μg Dex),with a control group that received a sham operation.The pain thresholds of KOA rats were measured using a Pres-sure Application Measurement(PAM)at different intervals before to delivery and 4,24,36,and 48 hours following administration;to gauge changes in discomfort,a CatWalk was used to assess the rats'average foot strength and maximum contact area before,four,twenty-four,and forty-eight hours after treatment.A portion of the rats were put to sleep at four,twenty-four,and forty-eight hours following the injection,and the joint synovium was removed for paraffin sectioning.Immunohistochemistry was used to identify the expression of GAP43 in the synovium,whereas immunofluorescence was used to identify the expression of CGRP in the same tissue.Results The average strength and maximum contact area of the foot and claw decreased(P＜0.01),and the pain threshold decreased(P＜0.01)in the model group compared to the sham operation group.The PB21+Dex group experienced a delayed pain threshold lowering time delay when compared to the PB21 and Dex treatment groups alone.Up to 48 hours lat-er,the combination administration group's average strength and maximum contact area of the foot paw remained ele-vated,and there was a statistically significant difference(P＜0.05)between the combined administration group and PB21 and Dex alone.GAP43 and CGRP expression levels in synovial tissue were detected.The results indica-ted that PB21 and Dex alone could lower protein expression levels at 4 and 24 h at the two time points,and that the PB21+Dex group could still significantly lower GAP43 and CGRP expression levels at 48 h.At the 48 h time point,the PB21+Dex group was statistically significant when compared to the PB21 and Dex alone administration group(P＜0.05).Conclusion In summary low dose dexamethasone can prolong the analgesic effect of PB21 on KOA rats,which is connected to reducing the expression of pain related proteins CGRP and GAP43.

Objective : To investigate the partial mechanism and effect of transplanting with human umbilical cordderived mesenchymal stem cells (hUC⁃MSCs) to repair articular cartilage defects in a rat model. Methods : Critical⁃sized osteochondral defects were created in the trochlear grooves of rat femurs. The hUC⁃MSCs were transplanted into the defect of experimental knees. Sham group and model group knees were transplanted with saline. The effects of articular cartilage repair were evaluated at 10 weeks after surgery with International Cartilage Repair Society (ICRS) repair score , histological examination and immunohistochemical analysis. The effects of hUC⁃MSCs on the proliferation and migration of chondrocytes were detected by Transwell in vitro. Results : After transplanting with hUC⁃MSCs , the articular surfaces of the defect sites were changed smoother thanthose of the model group , and the cellular morphology and arrangement were also improved in Safranin O staining or Masson staining results. Similar to surrounding normal articular cartilage tissue after treatment for 10 weeks , and the ICRS repair score was signifision of type Ⅱ (Col Ⅱ ) collagen and decrease the level of type Ⅰ collagen( Col Ⅰ ) in the articular defect site. Meanwhile , the increased protein expression of SOX9 and protein transportation to the nucleus were observed after treatment with hUC⁃MSCs for 10 weeks. In vitro , chondrocytes could be proliferated and migrated after co⁃cultured with hUC⁃MSCs. Conclusion Transplanting with hUC⁃MSCs can promote cartilage repair, and its role maybe related to the protection of the cartilage matrix and the promotion of chondrocyte proliferation and migration.

Objective : To study the protective effect and mechanism of iPSC⁃MSCs on cartilage matrix in knee oste⁃ oarthritis (KOA) patients in vitro. Methods : Cartilage tissues removed from KOA patients with joint replacement surgery were collected and subjected to tissue and cellular experiments , respectively. Cartilage tissue was cut into small pieces and randomly divided into a control group , an IL⁃1β ( 10 ng/ml) induction group , and iPSC⁃MSCs 96 h and then co⁃cultured with different amounts of iPSC⁃MSCs ( 1 × 104 , 1 × 105 , 1 × 106 ) cells for 72 h. For in tissues , the pathological changes of isolated cartilage tissues were examined by HE staining. The levels of ADAMTS⁃4 , ADAMTS⁃5 , and type II collagen expression were analyzed by immunohistochemistry , while the levels of MMP13 , IL⁃6 , and IL⁃10 in culture supernatants were detected by ELISA kits. The 2 to 5 generations of chondrocytes , which were extracted from cartilage tissue of KOA patients , were stimulated with IL⁃1β ( 10 ng/ml) for 48 h and then co⁃cultured with different concentrations of iPSC⁃MSCs ( 1 × 104 , 1 × 105 , 1 × 106 ) cells for 72 h. Immunofluorescence and Western blot detected the expression of RUNX2 , ADAMTS⁃4 , and ADAMTS⁃5 in chondrocytes. Results : Comparison with the control group , in the IL⁃1β⁃induced group , the levels of RUNX2 , ADAMTS⁃4 , and ADAMTS⁃5 increased , the level of type II collagen decreased , the levels of MMP⁃13 and IL⁃6 in the culture supernatant increased ( P < 0. 05) , and the level of IL⁃10 decreased ( P < 0. 05) ; Compared with the IL⁃1β⁃induced decreased the expression of RUNX2 , ADAMTS⁃4 , and ADAMTS⁃5 , promoted type II collagen expression and elevated IL⁃10 levels. Conclusion iPSC⁃MSCs inhibited ADAMTS⁃4 and ADAMTS⁃5 expression in vitro , reduced cartilage extracellular matrix degradation , and played a role in articular cartilage protection.

Objective: To establish and evaluate the pyroptosis model of rat chondrocytes induced by tumor necrosis factor-α(TNF-α). Methods: A two-step enzymatic digestion method was used to obtain rat articular chondrocytes, inverted phase contrast microscope was used to observe the morphological structure of chondrocytes. Toluidine blue staining and type Ⅱ collagen(Col Ⅱ) staining were used to identify chondrocytes. Different mass concentrations of TNF-α(5, 10, 20, 40 ng/ml) were used to establish the pyroptosis model with TNF-α(0 ng/ml) as the control group. Cell viability was detected by CCK-8 method and proteins of pyroptosis signal were detected by Western blot. The levels of IL-1β and IL-18 in cultured supernatants were examined by ELISA kits. The expression of gasdermin D(GSDMD) in chondrocytes was detected by immunofluorescence. Scanning electron microscope was used to observe the morphological changes of chondrocyte. Results: Compared with the control group, the cell viability of rat chondrocytes gradually decreased with the increase of TNF-α concentration and the expression of nucleotide-binding and oligomerization domain-like receptor containing protein 3(NLRP3), caspase-1, GSDMD and Phospho-NF-κB p65(P-p65) proteins increased. Furthermore, TNF-α(20 ng/ml) could up-regulate the expression of matrix metalloproteinase-13(MMP-13), the fluorescence expression of GSDMD and the levels of IL-1β and IL-18 while the expression of Col Ⅱ was distinctly reduced. What′s more, the articular chondrocytes were swollen,and the microstructure was destroyed. Conclusion TNF-α(20 ng/ml) can cause the swelling and death of rat chondrocytes, degradation of cartilage matrix and activation of pyroptosis signaling pathway. The pyroptosis model of rat chondrocytes was successfully established.

Objective: To establish a method for isolation and culture of primary endothelial cells from non-human primate coronary arteries, and to provide a cell model for the study of human coronary endothelial cells. Methods: The coronary arteries of macaca mulattas were separated aseptically. The primary endothelial cells were separatedviatissue adhesion after collagenase digestion. CD31 positive cells were detected and sorted by flow cytometry to determine the purity of endothelial cells. After stimulation with prostaglandin E2(PGE2), the cellular viability and proliferation ability of primary coronary endothelial cells from macaca mulattas were evaluated by high-content cell imaging and CCK-8 assay, and the migration ability and tube function of primary coronary endothelial cells from macaca mulattas were measured by Transwell method and Matrigel glue method, respectively. Results: The confluence percentage of primary coronary artery cells of macaca mulattas was about 80% after 10-14 daysin vitroculture, and the cellular morphology was irregular polygons and paver shape. The purity of endothelial cells was about 31.7% by flow cytometry. After sorting, the purity of endothelial cells was confirmed by flow cytometry, which was more than 95%. PGE2could significantly up-regulate the proliferation, migration and tube formation abilities of primary coronary endothelial cells of macaca mulattas. Conclusion This study successfully established the isolation and culture method of primary coronary endothelial cells from macaca mulattas, and proved that it could be used as anin vitrocell model to simulate human coronary endothelial cells through functional studies.