TNF-deficient mice, including those lacking TNF solely in the kidney, had blunted hypertensive responses to angiotensin II and reduced end-organ damage compared to wild-type mice.
Does kidney-derived TNF-α contribute to angiotensin II-induced blood pressure elevation and renal damage in mice?
Kidney-derived TNF-α promotes angiotensin II-induced hypertension by limiting renal nitric oxide generation, highlighting a localized inflammatory mechanism in hypertension.
Immune system activation contributes to the pathogenesis of hypertension and the resulting progression of chronic kidney disease. In this regard, we recently identified a role for proinflammatory Th1 T-lymphocyte responses in hypertensive kidney injury. Because Th1 cells generate interferon-γ and tumor necrosis factor-α (TNF-α), we hypothesized that interferon-γ and TNF-α propagate renal damage during hypertension induced by activation of the renin-angiotensin system. Therefore, after confirming that mice genetically deficient of Th1 immunity were protected from kidney glomerular injury despite a preserved hypertensive response, we subjected mice lacking interferon-γ or TNF-α to our model of hypertensive chronic kidney disease. Interferon deficiency had no impact on blood pressure elevation or urinary albumin excretion during chronic angiotensin II infusion. By contrast, TNF-deficient (knockout) mice had blunted hypertensive responses and reduced end-organ damage in our model. As angiotensin II-infused TNF knockout mice had exaggerated endothelial nitric oxide synthase expression in the kidney and enhanced nitric oxide bioavailability, we examined the actions of TNF-α generated from renal parenchymal cells in hypertension by transplanting wild-type or TNF knockout kidneys into wild-type recipients before the induction of hypertension. Transplant recipients lacking TNF solely in the kidney had blunted hypertensive responses to angiotensin II and augmented renal endothelial nitric oxide synthase expression, confirming a role for kidney-derived TNF-α to promote angiotensin II-induced blood pressure elevation by limiting renal nitric oxide generation.
Zhang et al. (Wed,) conducted a other in Angiotensin II-dependent hypertension and chronic kidney disease. TNF-α deficiency (global or kidney-specific via transplantation) vs. Wild-type mice was evaluated on Blood pressure elevation and end-organ damage. TNF-deficient mice, including those lacking TNF solely in the kidney, had blunted hypertensive responses to angiotensin II and reduced end-organ damage compared to wild-type mice.