Interleukin 6 underlies angiotensin II-induced hypertension and chronic renal damage

Area of Science:

• Nephrology
• Immunology
• Cardiovascular Research

Background:

• Chronic kidney disease (CKD) is a major health issue linked to hypertension, fibrosis, and renal failure.
• The exact causes and mechanisms of CKD progression, particularly the role of inflammation, are not fully understood.
• Increased inflammatory responses are observed in CKD, but causative factors remain elusive.

Purpose of the Study:

• To investigate the role of interleukin 6 (IL-6) in the pathogenesis of chronic kidney disease (CKD).
• To determine if angiotensin II induces IL-6 production in the kidney and if IL-6 contributes to hypertension and renal fibrosis.
• To explore IL-6 as a potential therapeutic target for managing CKD.

Main Methods:

• Measured IL-6 expression in kidney tissues from CKD patients and hypertension-affected CKD patients.
• Utilized angiotensin II infusion in mice to study IL-6 induction and the effects of IL-6 genetic deletion on hypertension and renal pathology.
• Investigated the mechanistic link between angiotensin II signaling, IL-6, fibrotic gene expression, and endothelin-1 (ET-1) in human and mouse kidney cells.

Main Results:

• Significantly elevated IL-6 levels were found in kidneys of CKD patients, with higher levels in those with hypertension.
• Angiotensin II was identified as a key inducer of kidney IL-6 in mice.
• Genetic deletion of IL-6 in mice reduced hypertension, renal injury, and fibrosis in response to angiotensin II, and IL-6 directly induced fibrotic and ET-1 gene expression.

Conclusions:

• Angiotensin II stimulates IL-6 production in the kidney, contributing to both hypertension and CKD progression.
• IL-6 plays a significant pathogenic role in CKD by promoting fibrotic and ET-1 gene expression.
• Targeting IL-6 signaling presents a promising novel therapeutic strategy for managing CKD.