Allergic inflammation requires the orchestration of altered gene expression in the target tissue and in the infiltrating immune cells. The transcription factor STAT6 is critical in activating cytokine gene expression and cytokine signaling both in the immune cells and in target tissue cells including airway epithelia, keratinocytes and esophageal epithelial cells. STAT6 is activated by the cytokines IL-4 and IL-13 to mediate the pathogenesis of allergic disorders such as asthma, atopic dermatitis, food allergy and eosinophilic esophagitis (EoE). In this review, we summarize the role of STAT6 in allergic diseases, its interaction with the co-factor PARP14 and the molecular mechanisms by which STAT6 and PARP14 regulate gene transcription.
Asthma ; Cytokines ; Dermatitis, Atopic ; Eosinophilic Esophagitis ; Epithelial Cells ; Food Hypersensitivity ; Gene Expression ; Humans ; Inflammation* ; Interleukin-13 ; Interleukin-4 ; Keratinocytes ; Transcription Factors

Objective: Traumatic brain injury (TBI) is characterized by damage to the blood-brain barrier, inflammation, and edema formation. In this pilot study, we aimed to investigate the effects of a complement inhibitor, C1-esterase inhibitor (C1 INH), on brain edema and inflammation in a rat model of mild TBI. Methods: Thirty-six male Sprague Dawley rats were randomly assigned to control, TBI, or TBI plus C1 INH groups. TBI and TBI plus C1 INH rats received an injection of saline or 25 IU/kg C1 INH, respectively, with TBI using a weight drop model. Control rats received saline only. Rats were subsequently euthanized and their brain tissue harvested for analysis. The primary outcome was the extent of edema as assessed by the brain’s water content. Secondary outcomes included enzyme-linked immunosorbent assays to determine levels of pro-inflammatory mediators. Results: Tumor necrosis factor-α levels were significantly greater in TBI rats than control rats, indicating that inflammation was generated by the weight drop impact. Brain water content following TBI was significantly different between TBI rats treated with C1-INH (78.7%±0.12), untreated TBI rats (79.3%±0.12), and control rats (78.6%±0.15, P=0.001). There was a significant decrease in C3a and interleukin 2 levels among C1 INH–treated rats compared with untreated TBI rats, but no change in levels of tumor necrosis factor-α and S100β. Conclusion C1-INH inhibited the complement pathway, suggesting that C1-INH may have a therapeutic benefit in TBI. Further studies are needed to investigate the effect of C1-INH on clinical outcomes.