Objective: Internet weight loss programs have become widely available as alternatives to standard treatment, but few data are available on their efficacy. This study aimed to investigate the effectiveness of a structured behavioral weight loss website (VTrim) vs. a commercial weight loss website (http://eDiets.com). Research Methods and Procedures: A randomized, controlled trial was conducted from February 2003 to March 2005, in 124 overweight and obese subjects ages 18 years and older with a BMI of 25 to 39.9 kg/m2 (mean age, 47 ± 9 years; BMI, 32 ± 3 kg/m2; 20% men). Analyses were performed for the 88 subjects who had complete follow‐up data. Participants were randomly assigned to 12‐month VTrim (n = 62) or http://eDiets.com (n = 62) intervention. VTrim participants had access to a therapist‐led structured behavioral weight loss program delivered on‐line. http://eDiets.com subjects had access to a self‐help commercial on‐line weight loss program. Body weight, social support, and use of website components were measured at 0, 6, and 12 months. Results: Repeated‐measures analyses showed that the VTrim group lost significantly more weight than the http://eDiets.com group at 6 months (8.3 ± 7.9 kg vs. 4.1 ± 6.2 kg; p = 0.004) and maintained a greater loss at 12 months (7.8 ± 7.5 kg vs. 3.4 ± 5.8 kg; p = 0.002). More participants in the VTrim group maintained a 5% weight loss goal (65% vs. 37.5%; p = 0.01) at 12 months. Discussion: An on‐line, therapist‐led structured behavioral weight loss website produced greater weight loss than a self‐help commercial website. Because commercial sites have great potential public health impact, future research should investigate the feasibility of incorporating a more structured behavioral program into a commercial application.

SummaryBackground-Metformin might reduce insulin requirement and improve glycaemia in patients with type 1 diabetes, but whether it has cardiovascular benefits is unknown. We aimed to investigate whether metformin treatment (added to titrated insulin therapy) reduced atherosclerosis, as measured by progression of common carotid artery intima-media thickness (cIMT), in adults with type 1 diabetes at increased risk for cardiovascular disease.

Summary FGF21 contributes to the metabolic response to dietary protein restriction, and prior data implicate GCN2 as the amino acid sensor linking protein restriction to FGF21 induction. Here we demonstrate the persistent and essential role of FGF21 in the metabolic response to protein restriction. We show that FGF21-KO mice are fully resistant to low protein (LP)-induced changes in food intake, energy expenditure (EE), body weight gain and metabolic gene expression for 6 months. GCN2-KO mice recapitulate this phenotype, but LP-induced effects on food intake, EE, and body weight subsequently begin to appear after 14 days on diet. We show that this delayed emergence of LP-induced metabolic effects in GCN2-KO mice coincides with a delayed but progressive increase of hepatic FGF21 expression and blood FGF21 concentrations over time. These data indicate that FGF21 is essential for the metabolic response to protein restriction, but that GCN2 is only transiently required for LP-induced FGF21.

Highlights d Mice adaptively alter metabolism and food choice during protein restriction d The liver hormone FGF21 is robustly increased by protein restriction d Metabolic responses to protein restriction require FGF21 signaling in the brain d Brain FGF21 also mediates adaptive changes in macronutrient selection

Diabetes mellitus results from immune cell invasion into pancreatic islets of Langerhans, eventually leading to selective destruction of the insulin-producing ␤-cells. How this process is initiated is not well understood. In this study, we investigated the regulation of the CXCL1 and CXCL2 genes, which encode proteins that promote migration of CXCR2 ϩ cells, such as neutrophils, toward secreting tissue. Herein, we found that IL-1␤ markedly enhanced the expression of the CXCL1 and CXCL2 genes in rat islets and ␤-cell lines, which resulted in increased secretion of each of these proteins. CXCL1 and CXCL2 also stimulated the expression of specific integrin proteins on the surface of human neutrophils. Mutation of a consensus NF-B genomic sequence present in both gene promoters reduced the ability of IL-1␤ to promote transcription. In addition, IL-1␤ induced binding of the p65 and p50 subunits of NF-B to these consensus B regulatory elements as well as to additional B sites located near the core promoter regions of each gene. Additionally, serine-phosphorylated STAT1 bound to the promoters of the CXCL1 and CXCL2 genes. We further found that IL-1␤ induced specific posttranslational modifications to histone H3 in a time frame congruent with transcription factor binding and transcript accumulation. We conclude that IL-1␤-mediated regulation of the CXCL1 and CXCL2 genes in pancreatic ␤-cells requires stimulus-induced changes in histone chemical modifications, recruitment of the NF-B and STAT1 transcription factors to genomic regulatory sequences within the proximal gene promoters, and increases in phosphorylated forms of RNA polymerase II.

To understand features of human obesity and type 2 diabetes mellitus (T2D) that can be recapitulated in the mouse, we compared C57BL/6J mice fed a Western-style diet (WD) to weight-matched genetically obese leptin receptor-deficient mice (db/db). All mice were monitored for changes in body composition, glycemia, and total body mass. To objectively compare diet-induced and genetic models of obesity, tissue analyses were conducted using mice with similar body mass. We found that adipose tissue inflammation was present in both models of obesity. In addition, distinct alterations in metabolic flexibility were evident between WD-fed mice and db/db mice. Circulating insulin levels are elevated in each model of obesity, while glucagon was increased only in the db/db mice. Although both WD-fed and db/db mice exhibited adaptive increases in islet size, the db/db mice also displayed augmented islet expression of the dedifferentiation marker Aldh1a3 and reduced nuclear presence of the transcription factor Nkx6.1. Based on the collective results put forth herein, we conclude that db/db mice capture key features of human T2D that do not occur in WD-fed C57BL/6J mice of comparable body mass.

The CXCL10 gene encodes a peptide that chemoattracts a variety of leukocytes associated with type 1 and type 2 diabetes. The present study was undertaken to determine the molecular mechanisms required for expression of the CXCL10 gene in response to IL-1β and IFN-γ using rat islets and β cell lines. IL-1β induced the expression of the CXCL10 gene and promoter activity, whereas the combination of IL-1β plus IFN-γ was synergistic. Small interfering RNA–mediated suppression of NF-κB p65 markedly inhibited the ability of cytokines to induce the expression of the CXCL10 gene, whereas targeting STAT1 only diminished the synergy provided by IFN-γ. Furthermore, we found that a JAK1 inhibitor dose dependently reduced IFN-γ–controlled CXCL10 gene expression and promoter activity, concomitant with a decrease in STAT1 phosphorylation at Tyr701. We further discovered that, although the Tyr701 phosphorylation site is inducible (within 15 min of IFN-γ exposure), the Ser727 site within STAT1 is constitutively phosphorylated. Thus, we generated single-mutant STAT1 Y701F and double-mutant STAT1 Y701F/S727A adenoviruses. Using these recombinant adenoviruses, we determined that overexpression of either the single- or double-mutant STAT1 decreased the IFN-γ–mediated potentiation of CXCL10 gene expression, promoter activity, and secretion of protein. Moreover, the Ser727 phosphorylation was neither contingent on a functional Y701 site in β cells nor was it required for cytokine-mediated expression of the CXCL10 gene. We conclude that the synergism of IL-1β and IFN-γ to induce expression of the CXCL10 gene requires NF-κB, STAT1 phosphorylated at Tyr701, recruitment of coactivators, and acetylation of histones H3 and H4.

Proinflammatory cytokines impact islet ␤-cell mass and function by altering the transcriptional activity within pancreatic ␤-cells, producing increases in intracellular nitric oxide abundance and the synthesis and secretion of immunomodulatory proteins such as chemokines. Herein, we report that IL-1␤, a major mediator of inflammatory responses associated with diabetes development, coordinately and reciprocally regulates chemokine and insulin secretion. We discovered that NF-B controls the increase in chemokine transcription and secretion as well as the decrease in both insulin secretion and proliferation in response to IL-1␤. Nitric oxide production, which is markedly elevated in pancreatic ␤-cells exposed to IL-1␤, is a negative regulator of both glucose-stimulated insulin secretion and glucose-induced increases in intracellular calcium levels. By contrast, the IL-1␤-mediated production of the chemokines CCL2 and CCL20 was not influenced by either nitric oxide levels or glucose concentration. Instead, the synthesis and secretion of CCL2 and CCL20 in response to IL-1␤ were dependent on NF-B transcriptional activity. We conclude that IL-1␤-induced transcriptional reprogramming via NF-B reciprocally regulates chemokine and insulin secretion while also negatively regulating ␤-cell proliferation. These findings are consistent with NF-B as a major regulatory node controlling inflammation-associated alterations in islet ␤-cell function and mass. chemokine; inflammation; insulin secretion; interleukin-1; nitric oxide THE PROGRESSION TO BOTH TYPE 1 (T1DM) and type 2 diabetes mellitus (T2DM) proceeds via immune cell-associated alterations in islet ␤-cell mass and function. Alterations in islet ␤-cell mass and function are two major determinants controlling the total amount of insulin produced and secreted in response to physiological stimuli (e.g., glucose). Proinflammatory cytokines such as IL-1␤ and IFN␥ contribute significantly to losses in islet ␤-cell viability and insulin secretion. Islet