Preliminary study of Sonic Hedgehog signaling pathway in rheumatoid arthritis

AIM:To investigate the expression of Sonic Hedgehog(Shh) signaling pathway-associated factors in peripheral blood mononuclear cells(PBMCs) and synovial tissues of rheumatoid arthritis(RA).METHODS:The mRNA expression levels of Shh,Ptchl and Glil in PBMCs of 35 RA patients,and 35 age-and sex-matched healthy controls were analyzed by real-time PCR.The expression of Shh,Ptchl and Glil in synovial tissues was detected by immunohistochemisty assay in 10 RA patients and 5 patients with traumatic or meniscal injury(no arthritis) as control group.All patients accorded with the American College of Rheumatology(ACR) 1987 revised classification criteria for determining RA,and the score of DAS28 was≥3.2.RESULTS;The results of real-time PCR showed that the expression of Shh and Glil mRNA in RA patients was higher than that in the controls(Shh and Glil in RA were 1.36±1.48 and 1.15±0.68, while Shh and Glil in control group were 0.47±0.25 and 0.49±0.05,respectively).The mRNA expression of Ptchl between the 2 groups had no significant difference.Similarly,the results of immunohistochemistry assay showed that the positive staining rates of Shh and Glil in RA group were higher than those in control group.However,no difference of Ptchl positive staining rate between the 2 groups was observed(P 0.05).CONCLUSION:The positive expression of Shh and Glil indicates the activation of Shh signaling pathway in the RA patients.