ABSTRACT
Osteonecrosis of femoral head (ONFH) is one of the complications of systemic lupus erythematosus (SLE), which is characterized by complex pathogenesis and difficult treatment, and is the main cause of SLE-induced disability. Previous studies have confirmed that the JAK/STAT signaling pathway is involved in the pathological process of SLE, and the activation of JAK/STAT has also been found to be related to the occurrence of ONFH. Therefore, we speculated that the JAK/STAT signaling pathway may play an important role in the occurrence and development of SLE-ONFH. 30 female MRL/lpr mice were randomly divided into three groups: the model group (Lipopolysaccharide/24 hours, twice + Methylprednisolone/24 hours, 3 times), the control group (equal amount of PBS) and the treatment group (the model group + JAK1/2 inhibitors Baricitinib/day, 6 weeks), with 10 mice in each group. The results showed that the grip value of the model group was significantly lower than that of the control group at the 4th and 6th week (P < 0. 05), and that of the treatment group was better than that of the model group at the 6th week (P < 0. 05). At the 6th week, the mice were sacrificed to take the bilateral femoral head, and the morphology and HE staining pathological changes of the femoral head were observed. The results showed that the femoral head of the control group was spherical, transparent, hard and without cartilage defects, while that of the model group was irregular, rough, gray in color and partial defects of the femoral head. The performance of the mice in the treatment group was basically similar to that in the model group. And the overall appearance of the femoral head was more irregular than that in the control group. The color was darker than that in the control group, and there was a partial defect of the femoral head, but the degree was not as serious as that in the model group. The empty bone lacuna rate in the model group and treatment group were significantly higher than that in the control group (P < 0. 05), and the empty bone lacuna rate in the treatment group was lower than that in the model group (P < 0. 05). Western blotting, ELISA and RT-qPCR were used to detect the protein expression, phosphorylation levels, mRNA expression of the JAK/STAT pathway (JAK1, JAK2, JAK3, STAT3) in local bone tissues, and the expression of IL-6 and TNF- α in serum and local tissues. The mRNA expression of IL-6, TNF-α and STAT3 in bone tissues of the model group were significantly higher than that of the control group and treatment group, and the content of serum IL-6 and TNF- α of the model group were significantly higher than that of the treatment group and control group. The cartilage catabolic metabolites ADAMTS-4, MMP-13 and JAK/STAT pathway related proteins JAK1, p-JAK1, JAK2, p-JAK2, STAT3 and pSTAT3 in the model group were significantly higher than those in the control group and treatment group. In summary, the JAK/STAT signaling pathway is involved in the pathogenesis of ONFH in MRL/lpr lupus erythematosus mice. Selective JAK1/2 inhibitors can effectively inhibit ONFH inflammation, improve bone structures and joint functions, and may become an effective therapeutic drug for SLE ONFH.
ABSTRACT
PURPOSE: We aimed to clarify the risk factors associated with the development of ONFH by comparing patients with hematologic diseases and osteonecrosis of the femur head (ONFH) to those patients without ONFH and who have hematologic diseases MATERIALS AND METHODS: The study population was limited to the patients admitted to our Hematology-Oncology department from 1 January 1994 to 31 May 2007. The patients were divided into 2 groups (those with ONFH, 54 patients and those without ONFH, 54 patients) and the risk factors for ONFH were evaluated by a comparative analysis. We analyzed the effect of a history of bone marrow transplantation (BMT), graft-versus-host disease (GVHD), total body radiation (TBI) and the amount of steroid used as the risk factors for ONFH. RESULTS: On the multiple logistic regression analysis, a total steroid use of >g/BMI was statistically identified as a significant risk factor for ONFH. The history of BMT and TBI were not statistically correlated with the development of ONFH. Among the patients with BMT, allogenic BMT and a history of GVHD were not statistically correlated with the development of ONFH on the multiple logistic regression analysis. CONCLUSION: Patients with hematologic diseases and who have used steroid >1.5g/BMI should carefully observed because they are more likely to develop ONFH.