Rationale Endothelial dysfunction is a characteristic feature of diabetes and obesity in animal models and humans. Deficits in nitric oxide production by endothelial nitric oxide synthase (eNOS) are associated with insulin resistance, which is exacerbated by high fat diet. Nevertheless, the metabolic effects of increasing eNOS levels have not been studied. Objective The current study was designed to test whether overexpression of eNOS would prevent diet-induced obesity and insulin resistance. Methods and Results In db/db mice and in high fat-fed wild-type (WT) C57BL/6J mice, the abundance of eNOS protein in adipose tissue was decreased without significant changes in eNOS levels in skeletal muscle or aorta. Mice overexpressing eNOS (eNOS-TG mice) were resistant to diet-induced obesity and hyperinsulinemia, although systemic glucose intolerance remained largely unaffected. In comparison with WT mice, high fat-fed eNOS-TG mice displayed a higher metabolic rate and attenuated hypertrophy of white adipocytes. Overexpression of eNOS did not affect food consumption or diet-induced changes in plasma cholesterol or leptin levels, yet plasma triglycerides and fatty acids were decreased. Metabolomic analysis of adipose tissue indicated that eNOS overexpression primarily affected amino acid and lipid metabolism; subpathway analysis suggested changes in fatty acid oxidation. In agreement with these findings, adipose tissue from eNOS-TG mice showed higher levels of PPAR-α and PPAR–γ gene expression, elevated abundance of mitochondrial proteins, and a higher rate of oxygen consumption. Conclusions These findings demonstrate that increased eNOS activity prevents the obesogenic effects of high fat diet without affecting systemic insulin resistance, in part, by stimulating metabolic activity in adipose tissue.

Adipose tissue metabolism is a critical regulator of adiposity and whole body energy expenditure; however, metabolic changes that occur in white adipose tissue (WAT) with obesity remain unclear. The purpose of this study was to understand the metabolic and bioenergetic changes occurring in WAT with obesity. Wild-type (C57BL/6J) mice fed a high-fat diet (HFD) showed significant increases in whole body adiposity, had significantly lower V̇(O₂), V̇(CO₂), and respiratory exchange ratios, and demonstrated worsened glucose and insulin tolerance compared with low-fat-fed mice. Metabolomic analysis of WAT showed marked changes in lipid, amino acid, carbohydrate, nucleotide, and energy metabolism. Tissue levels of succinate and malate were elevated, and metabolites that could enter the Krebs cycle via anaplerosis were mostly diminished in high-fat-fed mice, suggesting altered mitochondrial metabolism. Despite no change in basal oxygen consumption or mitochondrial DNA abundance, citrate synthase activity was decreased by more than 50%, and responses to FCCP were increased in WAT from mice fed a high-fat diet. Moreover, Pgc1a was downregulated and Cox7a1 upregulated after 6 wk of HFD. After 12 wk of high-fat diet, the abundance of several proteins in the mitochondrial respiratory chain or matrix was diminished. These changes were accompanied by increased Parkin and Pink1, decreased p62 and LC3-I, and ultrastructural changes suggestive of autophagy and mitochondrial remodeling. These studies demonstrate coordinated restructuring of metabolism and autophagy that could contribute to the hypertrophy and whitening of adipose tissue in obesity.

Autologous transplantation of cardiac progenitor cells (CPCs) alleviates myocardial dysfunction in the damaged heart; however, the mechanisms that contribute to their reparative qualities remain poorly understood. In this study, we examined CPC metabolism to elucidate the metabolic pathways that regulate their proliferative capacity. In complete growth medium, undifferentiated CPCs isolated from adult mouse heart proliferated rapidly (Td = 13.8 h). CPCs expressed the Glut1 transporter and their glycolytic rate was increased by high extracellular glucose concentration, in the absence of insulin. Although high glucose concentrations did not stimulate proliferation, glutamine increased CPC doubling time and promoted survival under conditions of oxidative stress. In comparison with glucose, pyruvate or BSA-palmitate, glutamine, when provided as the sole metabolic substrate, increased ATP-linked and uncoupled respiration. Although fatty acids were not used as respiratory substrates when present as a sole carbon source, glutamine-induced respiration was doubled in the presence of BSA-palmitate, suggesting that glutamine stimulates fatty acid oxidation. Additionally, glutamine promoted rapid phosphorylation of the mTORC1 substrate, p70S6k, as well as retinoblastoma protein, followed by induction of cyclin D1 and cdk4. Inhibition of either mTORC1 or glutaminolysis was sufficient to diminish CPC proliferation, and provision of cell permeable α-ketoglutarate in the absence of glutamine increased both respiration and cell proliferation, indicating a key role of glutamine anaplerosis in cell growth. These findings suggest that glutamine, by enhancing mitochondrial function and stimulating mTORC1, increases CPC proliferation, and that interventions to increase glutamine uptake or oxidation may improve CPC therapy.

Accumulation of immune cells in adipose tissue promotes insulin resistance in obesity. Although innate and adaptive immune cells contribute to adipose inflammation, the processes that sustain these interactions are incompletely understood. Here we show that obesity promotes the accumulation of CD11c+ adipose tissue immune cells that express C-C chemokine receptor 7 (CCR7) in mice and humans, and that CCR7 contributes to chronic inflammation and insulin resistance. We identified that CCR7+ macrophages and dendritic cells accumulate in adipose tissue in close proximity to lymph nodes (LNs) (i.e., perinodal) and visceral adipose. Consistent with the role of CCR7 in regulating the migration of immune cells to LNs, obesity promoted the accumulation of CD11c+ cells in LNs, which was prevented by global or hematopoietic deficiency of Ccr7. Obese Ccr7−/− mice had reduced accumulation of CD8+ T cells, B cells, and macrophages in adipose tissue, which was associated with reduced inflammatory signaling. This reduction in maladaptive inflammation translated to increased insulin signaling and improved glucose tolerance in obesity. Therapeutic administration of an anti-CCR7 antibody phenocopied the effects of genetic Ccr7 deficiency in mice with established obesity. These results suggest that CCR7 plays a causal role in maintaining innate and adaptive immunity in obesity.

Anterior knee pain arising from the patellofemoral joint may be a significant problem in the cerebral palsy (CP) population. The aim of this study was to classify patients with anterior knee pain based on etiology and organize orthopaedic management based on this classification. This study was a retrospective chart review of patients with CP and anterior knee pain admitted to the orthopaedic outpatient clinic between 1991 and 2003. Children with CP who had intractable anterior knee pain despite 6 months of conservative treatment with at least 2 years' follow-up were identified and included. The medical records, radiographs, and treatment protocols were screened. Patients were classified into 3 groups according to pathology. Group I consisted of 7 children with patella alta only. Group II consisted of 7 children with patellar inferior pole fractures. Group III consisted of 13 children with subluxated or dislocated patellas. Conservative treatment methods such as anti-inflammatory drugs, local ice packs, stretching exercises, and braces should be the first step in treatment. For those patients in whom conservative treatment was not effective, surgical treatment alternatives were discussed. Knee pain resolved in all patients after surgical treatment of the underlying pathology. Gait analysis can be performed for patients with patellofemoral subluxations to evaluate the rotational malalignment of the tibia and femur. In conclusion, anterior knee pain arising from the patellofemoral joint in patients with CP should be evaluated and treated to prevent future functional deterioration.

tissue metabolism is a critical regulator of adiposity and whole body energy expenditure; however, metabolic changes that occur in white adipose tissue (WAT) with obesity remain unclear. The purpose of this study was to understand the metabolic and bioenergetic changes occurring in WAT with obesity. Wild-type (C57BL/6J) mice fed a high-fat diet (HFD) showed significant increases in whole body adiposity, had significantly lower V O2, V CO2, and respiratory exchange ratios, and demonstrated worsened glucose and insulin tolerance compared with low-fat-fed mice. Metabolomic analysis of WAT showed marked changes in lipid, amino acid, carbohydrate, nucleotide, and energy metabolism. Tissue levels of succinate and malate were elevated, and metabolites that could enter the Krebs cycle via anaplerosis were mostly diminished in high-fat-fed mice, suggesting altered mitochondrial metabolism. Despite no change in basal oxygen consumption or mitochondrial DNA abundance, citrate synthase activity was decreased by more than 50%, and responses to FCCP were increased in WAT from mice fed a high-fat diet. Moreover, Pgc1a was downregulated and Cox7a1 upregulated after 6 wk of HFD. After 12 wk of high-fat diet, the abundance of several proteins in the mitochondrial respiratory chain or matrix was diminished. These changes were accompanied by increased Parkin and Pink1, decreased p62 and LC3-I, and ultrastructural changes suggestive of autophagy and mitochondrial remodeling. These studies demonstrate coordinated restructuring of metabolism and autophagy that could contribute to the hypertrophy and whitening of adipose tissue in obesity.

Objective: Obesity is a major risk factor for the development of several chronic diseases including type 2 diabetes and cardiovascular disease. Proper fat storage in white adipose tissue (WAT) is required to maintain insulin sensitivity and to preserve (cardio)vascular health. We hypothesize that endothelial and adipocyte progenitor cell populations (EPCs and APCs, respectively) must be appropriately balanced for physiological, as opposed to pathological, remodeling of WAT. Methods and Results: To determine the impact of nutrient excess on stem/progenitor cells in epididymal WAT, male C57BL/6J mice were placed on a high fat diet (HFD; 60% fat) for 12 weeks and changes in WAT stem cell populations were measured in the stromal vascular fraction by flow cytometry. Although the APC (CD24+/CD29+/Sca+/CD14-/CD45-) population, which has the capacity to differentiate into adipocytes both in vitro and in vivo , was not significantly changed with diet, Flk+/Sca+ EPCs were diminished, promoting a 4-fold decrease in the EPC/APC ratio (p <0.05, n = 6/group). To determine whether this deficit may be due to poor stem cell recruitment, mice were irradiated, and the bone marrow was repopulated with GFP+ donor marrow. The transplanted mice were then placed on a low fat diet (LFD; 10% fat) or HFD for 12 weeks, and WAT progenitor cells were again measured. Greater than 95% of the putative APCs in the WAT of HF-fed mice were GFP+ (p<0.0001, n=7-8/group), indicating a bone marrow-derived origin. Unexpectedly, less than 1% of the EPCs were GFP+ (p<0.001, n=7-8/group), which suggests that EPCs present in WAT are not derived from bone marrow in adult mice. Confocal analysis of WAT from HF-fed, bone marrow-transplanted mice showed little evidence of significant APC differentiation into triglyceride-laden adipocytes, suggesting that conditions associated with nutrient excess may impair the ability of the adipose organ to store fat properly. Conclusions: These results demonstrate that putative APCs, and not EPCs, in epididymal WAT are derived from bone marrow. Furthermore, our data suggest that conditions of nutrient excess promote an imbalance in EPCs and APCs, the stoichiometry of which may be critical for the development of new adipocytes and for proper storage of fat.

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