Clinical significance of the expression levels of serum transforming growth factor-β and CXC type chemokine ligand 13 in primary Sjogren's syndrome patients

CXCL13: a common target for immune-mediated inflammatory diseases

CXCL13 is a chemokine that plays an important role in the regulation and development of secondary lymphoid organs. CXCL13 is also involved in the regulation of pathological processes, particularly inflammatory responses, of many diseases. The function of CXCL13 varies depending on the condition of the host. In a healthy condition, CXCL13 is mainly secreted by mouse stromal cells or human follicular helper T cells, whereas in diseases conditions, they are produced by human peripheral helper T cells and macrophages in non-lymphoid tissues; this is termed ectopic expression of CXCL13. Ectopic CXCL13 expression is involved in the pathogenesis of various immune-mediated inflammatory diseases as it regulates the migration of B lymphocytes, T lymphocytes, and other immune cells in inflammatory sites as well as influences the expression of inflammatory factors. Additionally, ectopic expression of CXCL13 plays a key role in ectopic lymphoid organ formation. In this review, we focused on the sources of CXCL13 in different conditions and its regulatory mechanisms in immune-mediated inflammatory diseases, providing novel ideas for further research on targeting CXCL13 for the treatment of immune-mediated inflammatory diseases.

TGF-β signaling in health, disease, and therapeutics

Transforming growth factor (TGF)-β is a multifunctional cytokine expressed by almost every tissue and cell type. The signal transduction of TGF-β can stimulate diverse cellular responses and is particularly critical to embryonic development, wound healing, tissue homeostasis, and immune homeostasis in health. The dysfunction of TGF-β can play key roles in many diseases, and numerous targeted therapies have been developed to rectify its pathogenic activity. In the past decades, a large number of studies on TGF-β signaling have been carried out, covering a broad spectrum of topics in health, disease, and therapeutics. Thus, a comprehensive overview of TGF-β signaling is required for a general picture of the studies in this field. In this review, we retrace the research history of TGF-β and introduce the molecular mechanisms regarding its biosynthesis, activation, and signal transduction. We also provide deep insights into the functions of TGF-β signaling in physiological conditions as well as in pathological processes. TGF-β-targeting therapies which have brought fresh hope to the treatment of relevant diseases are highlighted. Through the summary of previous knowledge and recent updates, this review aims to provide a systematic understanding of TGF-β signaling and to attract more attention and interest to this research area.