Role of renin–angiotensin system in adipose tissue dysfunction

Abstract

Blockade of angiotensin II type 1 (AT 1 ) receptor improves insulin sensitivity and diabetic condition. In short-term regulation, angiotensin II changes lipid metabolism and in long-term regulation, it affects insulin sensitivity and adipocyte differentiation in adipose tissue. These effects are mainly mediated by AT 1 receptor. AT 1 receptor blocker improves insulin sensitivity and induces adipocyte differentiation by increasing peroxisome proliferator-activated receptor-c (PPARc) and transcription factors in adipose tissue in diabetic and atherosclerotic models. Clinical studies indicate that AT 1 receptor blockers prevent the new onset of diabetes and improve insulin sensitivity. On the other hand, AT 2 receptor stimulation appears to cause antagonistic actions against AT 1 receptor signaling. Although further investigations are necessary on the AT 2 receptor function in adipose tissue, studies using AT 2 receptor agonists, in addition to those using AT 1 receptor blockers, would contribute to the treatment of metabolic syndrome and associated pathological disorders.

Side Chain-oxidized Oxysterols Regulate the Brain Renin-Angiotensin System through a Liver X Receptor-dependent Mechanism

“…Animal studies have shown that ACE inhibitors enhance cognitive performance (48), and improve learning and retention of memory (49). On the other hand, overstimulation of AT1R leads to cognitive deficits and ischemic damage in mice (32,33), as well as hypertension, vascular brain damage, and insulin resistance in humans (50). Thus, it is tempting to suggest that a hypercholesterolemia-mediated overactivation of brain RAS, via the BBB permeable 27-OH, may contribute to neurodegenerative processes including memory impairment.…”

A functional siRNA screen identifies genes modulating angiotensin II-mediated EGFR transactivation

“…These include cellular growth (hypertrophy) and remodelling (fibrosis); dyslipidaemia; endothelial dysfunction, aneurysms and angiogenesis (Iwai and Horiuchi, 2009;Lu et al, 2008;Mehta and Griendling, 2007;Weiss et al, 2001); proinflammatory responses (Rompe et al, 2010;Schiffrin, 2010); stem cell programming and haematopoiesis (Heringer-Walther et al, 2009;Park and Zambidis, 2009;Zambidis et al, 2008); neuromodulation including cognition, memory and dementia (Li et al, 2010;Miners et al, 2009); and cancer, as reviewed by us (George et al, 2010).…”

Local Renin-Angiotensin System at Liver and Crosstalk with Hepatic Diseases

“…On the contrary, it is suggested that angiotensin receptor blocker could increase insulin secretion at animals with type-II diabetes. Additionally, it is reported to enhance glucose uptake at adipose tissue, one of the sensitive insulin organs, at AT2-knockdown animals [44]. Alternative RAS pathways, ACE2/An-1-7/Mas axis, might be the high beneficial effect on diabetes based on enhancing glucose reuptake, diminishing glycogen production, and insulin resistance in hepatocytes via Akt/PI3K/IRS-1/JNK insulin signaling.…”