Selected Molecular Events in the Pathogenesis of Sarcoidosis—Recent Advances

Sarcoidosis is an orphan inflammatory disorder that can virtually affect any organ or system in the body, although the lungs and lymph nodes are most frequently involved. Sarcoidosis is believed to derive from an interaction between environmental and genetic agents. Many studies emphasize a strong association between certain human leukocyte antigen (HLA) alleles and sarcoidosis susceptibility. Several new insights have allowed the further evaluation of other candidate genes with a potential function in the immunopathogenesis of sarcoidosis. This review summarizes recent advances in the identification of novel molecular markers that may play a role in different stages of disease, such as the acute phase of inflammation, granuloma formation and fibrosis. Furthermore, this article elucidates the role of both TGF-β/Smad and (HIF)-1a-VEGF-ING-4 signaling pathways in the development of sarcoidosis. The potential epigenetic regulation of the processes occurring in sarcoidosis by miRNA is also discussed.