Diabetes
-
C-C motif chemokine receptor (CCR)2 and its ligand, monocyte chemoattractant protein (MCP)-1, are pivotal for adipose tissue macrophage (ATM) recruitment and the development of insulin resistance. However, other chemokine systems also may play a role in these processes. In this study, we investigated the role of CCR5 in obesity-induced adipose tissue inflammation and insulin resistance. ⋯ The effects of loss of CCR5 were related to both reduction of total ATM content and an M2-dominant shift in ATM polarization. It is noteworthy that transplantation of Ccr5(-/-) bone marrow was sufficient to protect against impaired glucose tolerance. CCR5 plays a critical role in ATM recruitment and polarization and subsequent development of insulin resistance.
-
We evaluated the effects of hyperbaric oxygen therapy (HOT) on autoimmune diabetes development in nonobese diabetic (NOD) mice. Animals received no treatment or daily 60-min HOT 100% oxygen (HOT-100%) at 2.0 atmospheres absolute and were monitored for diabetes onset, insulitis, infiltrating cells, immune cell function, and β-cell apoptosis and proliferation. Cyclophosphamide-induced diabetes onset was reduced from 85.3% in controls to 48% after HOT-100% (P < 0.005) and paralleled by lower insulitis. ⋯ HOT-100% yielded reduced apoptosis (transferase-mediated dUTP nick-end labeling-positive insulin-positive cells; P < 0.01) and increased proliferation (bromodeoxyuridine incorporation; P < 0.001) of insulin-positive cells compared with controls. HOT reduces autoimmune diabetes incidence in NOD mice via increased resting T cells and reduced activation of DCs with preservation of β-cell mass resulting from decreased apoptosis and increased proliferation. The safety profile and noninvasiveness makes HOT an appealing adjuvant therapy for diabetes prevention and intervention trials.