C-reactive protein expression in adipose tissue of children with acute appendicitis.

OBJECTIVE: The aim of this study is to gain insights into the role of visceral adipose tissue as a source of C-reactive protein (CRP) in acute inflammation and to explore the potential relationship of CRP expression with the severity of appendicitis. METHODS: A total of 20 pediatric patients undergoing appendectomy were included in the study. Patients were divided into two groups according to appendicitis severity (uncomplicated and complicated). CRP levels were measured in visceral fat samples by western blotting, as well as in serum by biochemical testing. RESULTS: CRP was found to be expressed in visceral adipose tissue. The adipose tissue of patients with complicated appendicitis showed significantly higher CRP levels (p = 0.002) compared to patients with uncomplicated appendicitis. These results mirrored the CRP values obtained in serum (p = 0.018). CONCLUSION: In childhood, visceral adipose tissue is a source of CRP in acute inflammation, and its expression is potentially associated with the severity of local inflammation.

Suppressors of cytokine signaling regulate angiotensin II-activated Janus kinase-signal transducers and activators of transcription pathway in renal cells.

Suppressors of cytokine signaling (SOCS) family is constituted by cytokine-inducible proteins that modulate receptor signal transduction via tyrosine kinases, mainly the Janus kinase-signal transducers and activators of transcription (JAK-STAT) pathway. Differential SOCS expression was noted in renal cells that were incubated with inflammatory stimuli, but the role of SOCS in the pathogenesis of renal diseases is not yet well defined. Because angiotensin II (Ang II) plays a key role in renal disease, SOCS proteins were studied as a novel mechanism involved in the negative regulation of Ang II-mediated processes. Systemic Ang II infusion for 3 d increased the renal mRNA expression of SOCS-3 and SOCS-1. SOCS protein synthesis was found in glomerular mesangial area and tubules. In cultured mesangial cells and tubular epithelial cells, Ang II induced a rapid and transient SOCS-3 and SOCS-1 expression in parallel with JAK2 and STAT1 activation. In both cell types, overexpression of SOCS proteins prevented the STAT activation in response to Ang II. SOCS expression observed in Ang II-infused rats and in Ang II-stimulated cells was significantly inhibited by treatment with AT(1) but not AT(2) receptor antagonist and was attenuated in mesangial cells from AT(1a)-deficient mice, demonstrating the implication of AT(1) in those responses. In SOCS-3 knockdown studies, antisense oligonucleotides inhibited the expression of SOCS-3 and increased the Ang II-induced STAT activation and c-Fos/c-Jun expression, then resulting in a more severe renal damage. These results suggest that SOCS proteins may act as negative regulators of Ang II signaling in renal cells and implicate SOCS as important modulators of renal damage.