Pancreatic islet inflammation in type 2 diabetes: from alpha and beta cell compensation to dysfunction.
ABSTRACT Evidence in support of the concept of local pancreatic islet inflammation as a mechanism of beta cell failure in type 2 diabetes is accumulating. Observations in human islets from type 2 diabetic patients and rodent models of the disease indicate the increased presence of IL-1 driven cytokines and chemokines in pancreatic islets, concomitant with immune cell infiltration. Inflammation is the body's protective response to harmful stimuli and tissue damage. However, under chronic stress (e.g. metabolic stress in obesity and type 2 diabetes) the body's own defensive response may become deleterious to tissue function. Here, we summarize the current evidence that islet inflammation is a feature of type 2 diabetes, and discuss its role with respect to alpha and beta cell compensation and eventual beta cell failure.
Article: Cytokine-induced dicing and splicing in the beta-cell and the immune response in type 1 diabetes.Diabetes 02/2010; 59(2):335-6. · 8.29 Impact Factor
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ABSTRACT: Both common forms of diabetes have an inflammatory pathogenesis in which immune and metabolic factors converge on interleukin-1β as a key mediator of insulin resistance and β-cell failure. In addition to improving insulin resistance and preventing β-cell inflammatory damage, there is evidence of genetic association between diabetes and histone deacetylases (HDACs); and HDAC inhibitors (HDACi) promote β-cell development, proliferation, differentiation and function and positively affect late diabetic microvascular complications. Here we review this evidence and propose that there is a strong rationale for preclinical studies and clinical trials with the aim of testing the utility of HDACi as a novel therapy for diabetes.Molecular Medicine 01/2011; 17(5-6):378-90. · 3.76 Impact Factor
Article: Progression from high insulin resistance to type 2 diabetes does not entail additional visceral adipose tissue inflammation[show abstract] [hide abstract]
ABSTRACT: Abstract Obesity is associated with a low-grade chronic inflammation state. As a consequence, adipose tissue expresses pro-inflammatory cytokines that propagate inflammatory responses systemically elsewhere, promoting whole-body insulin resistance and consequential islet β-cell exhaustation. Thus, insulin resistance is considered the early stage of type 2 diabetes. However, there is evidence of obese individuals that never develop diabetes indicating that the mechanisms governing the association between the increase of inflammatory factors and type 2 diabetes are much more complex and deserve further investigation. We studied for the first time the differences in insulin signalling and inflammatory pathways in blood and visceral adipose tissue (VAT) of 20 lean healthy donors and 40 equal morbidly obese (MO) patients classified in high insulin resistance (high IR) degree and diabetes state. We studied the changes in proinflammatory markers and lipid content from serum; macrophage infiltration, mRNA expression of inflammatory cytokines and transcription factors, activation of kinases involved in inflammation and expression of insulin signalling molecules in VAT. VAT comparison of these experimental groups revealed that type 2 diabetic-MO subjects exhibit the same pro-inflammatory profile than the high IR-MO patients, characterized by elevated levels of IL-1β, IL-6, TNFα, JNK1/2, ERK1/2, STAT3 and NFκB. Our work rules out the assumption that the inflammation should be increased in obese people with type 2 diabetes compared to high IR obese. These findings indicate that some mechanisms, other than systemic and VAT inflammation must be involved in the development of type 2 diabetes in obesity.PLoS ONE 10/2012; 7(10):e48155. · 4.09 Impact Factor