ABSTRACT
Systemic sclerosis (SSc) is a complex and chronic autoimmune disease causing fibrosis in multiple tissues and organs. The cause of fibrosis may be related to the production of extracellular matrix (ECM) such as type Ⅰ and Ⅲ collagens, elastin and fibronectin resulting from the transformation of activated fibroblasts (FB) into muscle-forming fibroblasts (MFB). ECM could seriously damage the skin, lung, heart, kidney and other organs. At present, many studies have shown that several signaling pathways including TGF-β, mTOR, JAK/STAT, Wnt/β-Catenin, Hedgehog and Notch are involved in the proliferation of FB and the transformation of FB to MFB, which led to the production and deposition of a great quantity of ECM. Therefore, this article reviewed the relationship between these signaling pathways and fibrosis in SSc, hoping to provided reference for the development of effective treatments for SSc.
ABSTRACT
Porcine reproductive and respiratory syndrome virus (PRRSV) non-structural protein 7 (Nsp7) plays an important role in the induction of host humoral immune response and could serve as an ideal antigen for serological genotyping assay for PRRSV based on the significant difference in immunoreactivities of North American (NA) and European (EU) PRRSV Nsp7. In this study, Nsp7 of NA and EU PRRSVwas separately expressed and purified using prokaryotic expression system. The purified recombinant Nsp7 proteins reacted with serum antibodies against corresponding genotype PRRSV in Western blotting. However, nonspecific reaction of whole recombinant Nsp7 with antibodies against another genotype PRRSV was observed, indicating that whole NA PRRSV Nsp7 and EU PRRSV Nsp7 have similar antigenic epitopes and recombinant proteins could not be used for genotyping of antibodies against PRRSV. Based on the analysis of similar antigenic epitopes at the hydrophilic region of NA PRRSV Nsp7 and EU PRRSV Nsp7 by bioinformatics assessment, partial Nsp7 gene region deleted sequences encoding similar antigenic epitopes was constructed by fusion PCR. The recombinant truncated Nsp7 (NA-deltaNsp7 and EU-deltaNsp7, about 43 kDa) was expressed and the molecular weight was about 43 kDa. The results of Western blotting showed that NA-deltaNSP7 and EU-deltaNSP7 could be specifically recognized by positive serum to NA or EU PRRSV individually and nonspecific reaction was eliminated. This study provided a basis for further development of serological genotyping assay for North American and European genotype PRRSV infection.