Release Of Adipokines Research Articles

The Involvement of PPARs in the Causes, Consequences and Mechanisms for Correction of Cardiac Lipotoxicity and Oxidative Stress

Chronically-elevated plasma lipid concentrations, particularly when combined with high glucose, elicit a plethora of effects that cause the progressive deterioration of insulin sensitivity and ultimately cellular malfunction or death. This review addresses how metabolic abnormalities in white adipose tissue leading to excessive lipid or abnormal adipokine release can be modified by PPARγ activation. It also discusses the etiology of cardiac lipotoxicity and oxidative stress, in relation to imbalanced lipid delivery and clearance and how PPARα activation can be used to correct some of these effects.

Inflammation and metabolic dysfunction: links to cardiovascular diseases

Abdominal obesity is a major risk factor for cardiovascular disease, and recent studies highlight a key role of adipose tissue dysfunction, inflammation, and aberrant adipokine release in this process. An increased demand for lipid storage results in both hyperplasia and hypertrophy, finally leading to chronic inflammation, hypoxia, and a phenotypic change of the cellular components of adipose tissue, collectively leading to a substantially altered secretory output of adipose tissue. In this review we have assessed the adipo-vascular axis, and an overview of adipokines associated with cardiovascular disease is provided. This resulted in a first list of more than 30 adipokines. A deeper analysis only considered adipokines that have been reported to impact on inflammation and NF-κB activation in the vasculature. Out of these, the most prominent link to cardiovascular disease was found for leptin, TNF-α, adipocyte fatty acid-binding protein, interleukins, and several novel adipokines such as lipocalin-2 and pigment epithelium-derived factor. Future work will need to address the potential role of these molecules as biomarkers and/or drug targets.

Effects of Rilpivirine on Human Adipocyte Differentiation, Gene Expression, and Release of Adipokines and Cytokines

Rilpivirine is a nonnucleoside reverse transcriptase inhibitor (NNRTI) recently developed as a drug of choice for initial antiretroviral treatment of HIV-1 infection. Disturbances in lipid metabolism and, ultimately, in adipose tissue distribution and function are common concerns as secondary effects of antiretroviral treatment. Efavirenz, the most commonly used NNRTI, causes mild dyslipidemic effects in patients and strongly impaired adipocyte differentiation in vitro. In this study, we provide the first demonstration of the effects of rilpivirine on human adipocyte differentiation, gene expression, and release of regulatory proteins (adipokines and cytokines) and compare them with those caused by efavirenz. Rilpivirine caused a repression of adipocyte differentiation that was associated with impaired expression of the master adipogenesis regulators peroxisome proliferator-activated receptor gamma (PPARγ), CCAAT enhancer binding protein alpha (C/EBPα), and sterol regulatory element binding transcription factor 1 (SREBP-1) and their target genes encoding lipoprotein lipase and the adipokines leptin and adiponectin. Rilpivirine also repressed adiponectin release by adipocytes, but only at high concentrations, and did not alter leptin release. Rilpivirine induced the release of proinflammatory cytokines (interleukin-6 and -8, monocyte chemoattractant protein 1 [MCP-1], plasminogen activator inhibitor type 1 [PAI-1]) only at very high concentrations (10 μM). A comparison of the effects of rilpivirine and efavirenz at the same concentration (4 μM) or even at lower concentrations of efavirenz (2 μM) showed that rilpivirine-induced impairment of adipogenesis and induction of proinflammatory cytokine expression and release were systematically milder than those of efavirenz. It is concluded that rilpivirine causes an antiadipogenic and proinflammatory response pattern, but only at high concentrations, whereas efavirenz causes similar effects at lower concentrations.

Growth hormone, inflammation and aging

Mutant animals characterized by extended longevity provide valuable tools to study the mechanisms of aging. Growth hormone and insulin-like growth factor-1 (IGF-1) constitute one of the well-established pathways involved in the regulation of aging and lifespan. Ames and Snell dwarf mice characterized by GH deficiency as well as growth hormone receptor/growth hormone binding protein knockout (GHRKO) mice characterized by GH resistance live significantly longer than genetically normal animals. During normal aging of rodents and humans there is increased insulin resistance, disruption of metabolic activities and decline of the function of the immune system. All of these age related processes promote inflammatory activity, causing long term tissue damage and systemic chronic inflammation. However, studies of long living mutants and calorie restricted animals show decreased pro-inflammatory activity with increased levels of anti-inflammatory adipokines such as adiponectin. At the same time, these animals have improved insulin signaling and carbohydrate homeostasis that relate to alterations in the secretory profile of adipose tissue including increased production and release of anti-inflammatory adipokines. This suggests that reduced inflammation promoting healthy metabolism may represent one of the major mechanisms of extended longevity in long-lived mutant mice and likely also in the human.

Determinants of Increased Cardiovascular Disease in Obesity and Metabolic Syndrome

Obesity is associated with an increased mortality and morbidity for cardiovascular disease (CVD) and adipose tissue is recognised as an important player in obesity-mediated CVD. The diagnosis of the metabolic syndrome (MS) appears to identify substantial additional cardiovascular risk above and beyond the individual risk factors, even though the pathophysiology underlying this evidence is still unravelled. The inflammatory response related to fat accumulation may influence cardiovascular risk through its involvement not only in body weight homeostasis, but also in coagulation, fibrinolysis, endothelial dysfunction, insulin resistance (IR) and atherosclerosis. Moreover, there is evidence that oxidative stress may be a mechanistic link between several components of MS and CVD, through its role in inflammation and its ability to disrupt insulin-signaling. The cross-talk between impaired insulin-signaling and inflammatory pathways enhances both metabolic IR and endothelial dysfunction, which synergize to predispose to CVD. Persistent platelet hyperreactivity/activation emerges as the final pathway driven by intertwined interactions among IR, adipokine release, inflammation, dyslipidemia and oxidative stress and provides a pathophysiological explanation for the excess risk of atherothrombosis in this setting. Despite the availability of multiple interventions to counteract these metabolic changes, including appropriate diet, regular exercise, antiobesity drugs and bariatric surgery, relative failure to control the incidence of MS and its complications reflects both the multifactorial nature of these diseases as well as the scarce compliance of patients to established strategies. Evaluation of the impact of these therapeutic strategies on the pathobiology of atherothrombosis, as discussed in this review, will translate into an optimized approach for cardiovascular prevention.

Endocrine disorders and laminitis

SummaryTwo common endocrine disorders, pituitary pars intermedia dysfunction and equine metabolic syndrome, predispose horses and ponies to laminitis and may even induce the condition. The exact mechanisms involved in endocrinopathic laminitis have not been elucidated but hyperinsulinaemia and insulin resistance are currently being investigated. Obesity and regional adiposity may also contribute to laminitis susceptibility through the release of inflammatory cytokines and adipokines. In the case of pituitary pars intermedia dysfunction, glucocorticoid excess is likely to weaken hoof structures, alter vascular dynamics within the foot and induce or exacerbate insulin resistance. This review will summarise current theories regarding the pathophysiology of endocrinopathic laminitis and provide recommendations for the diagnosis and management of these common equine endocrine disorders.

Hypoxia reduces the response of human adipocytes towards TNFα resulting in reduced NF-κB signaling and MCP-1 secretion

Obesity is associated with adipose tissue hypoxia, and is thought to be linked to the chronic low-grade inflammation of adipose tissue, although the precise mechanism has remained unclear. In this study, we investigated the effect of a prominent hypoxia on human primary adipocyte secretion and tumor necrosis factor alpha (TNFα)-induced nuclear factor-κB (NF-κB) signaling. Using cytokine array and ELISA analysis, we compared the secretion patterns of normoxic and hypoxic (1% O(2)) adipocytes and observed various alterations in adipokine release. We could reproduce known alterations like an induction of interleukin (IL)-6, vascular endothelial growth factor, leptin and a reduction in adiponectin release under hypoxia. Interestingly, we observed a significant reduction in the secretion of macrophage chemotactic protein (MCP)-1 and other NF-κB-related genes, such as growth-regulated oncogene-α, eotaxin and soluble TNF-Receptor1 (TNF-R1) under hypoxia. TNFα stimulation of hypoxic adipocytes resulted in a significantly reduced phosphorylation of NF-κB and its inhibitor IκBα compared with normoxic cells. Furthermore, chronic treatment of hypoxic adipocytes with TNFα resulted in an expected higher secretion of the chemokines MCP-1 and IL-8, but under hypoxia, the secretion level was substantially lower than that under normoxia. This reduction in protein release was accompanied by a reduced mRNA expression of MCP-1, whereas IL-8 mRNA expression was not altered. Additionally, we observed a significantly reduced expression of the TNF-receptor TNF-R1, possibly being one cause for the reduced responsiveness of hypoxic adipocytes towards TNFα stimulation. In conclusion, human primary adipocytes show a basal and TNFα-induced reduction of MCP-1 release under hypoxia. This effect may be due to a reduced expression of TNF-R1 and therefore attenuated TNFα-induced NF-κB signaling. These observations demonstrate a reduced responsiveness of hypoxic adipocytes towards inflammatory stimuli like TNFα, which may represent an adaptation process to maintain adipose tissue function under hypoxia and inflammatory conditions.

A link between sleep loss, glucose metabolism and adipokines

The present review evaluates the role of sleep and its alteration in triggering problems of glucose metabolism and the possible involvement of adipokines in this process. A reduction in the amount of time spent sleeping has become an endemic condition in modern society, and a search of the current literature has found important associations between sleep loss and alterations of nutritional and metabolic contexts. Studies suggest that sleep loss is associated with problems in glucose metabolism and a higher risk for the development of insulin resistance and type 2 diabetes mellitus. The mechanism involved may be associated with the decreased efficacy of regulation of the hypothalamus-pituitary-adrenal axis by negative feedback mechanisms in sleep-deprivation conditions. In addition, changes in the circadian pattern of growth hormone (GH) secretion might also contribute to the alterations in glucose regulation observed during sleep loss. On the other hand, sleep deprivation stress affects adipokines - increasing tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) and decreasing leptin and adiponectin -, thus establishing a possible association between sleep-debt, adipokines and glucose metabolism. Thus, a modified release of adipokines resulting from sleep deprivation could lead to a chronic sub-inflammatory state that could play a central role in the development of insulin resistance and type 2 diabetes mellitus. Further studies are necessary to investigate the role of sleep loss in adipokine release and its relationship with glucose metabolism.

Atorvastatin and fenofibric acid differentially affect the release of adipokines in the visceral and subcutaneous cultures of adipocytes that were obtained from patients with and without mixed dyslipidemia

In this study, we compared the effects of atorvastatin and fenofibric acid, which were administered alone or in combination, on the secretory function of human adipocytes that were obtained from the visceral and subcutaneous adipose tissues of 19 mixed dyslipidemic patients and 19 subjects with a normal lipid profile.The adipocytes were incubated in vitro in the presence of atorvastatin and/or fenofibric acid. The secretory function of the cells was determined using ELISA assays.The visceral adipocytes released significantly more adiponectin and IL-6 and less PAI-1 than those that were obtained from subcutaneous tissue. The levels and patterns of adipokine release differed between the patients with or without lipid abnormalities and between the adipocytes that were obtained from visceral or subcutaneous adipose tissue. The culture that contained hypolipidemic drugs resulted in the significant changes of the release of adipokines. The effects of atorvastatin and fenofibric acid on the hormonal function of human adipocytes may be, in part, responsible for the clinical efficacy of these drugs in the prevention and treatment of dyslipidemia-related cardiovascular and metabolic disorders. The study supports the concept that the pleiotropic effects of fenofi-brate and atorvastatin may be, in part, a result of their impact on the secretory function of adipocytes.

The anti-inflammatory effects of exercise: mechanisms and implications for the prevention and treatment of disease

Regular exercise reduces the risk of chronic metabolic and cardiorespiratory diseases, in part because exercise exerts anti-inflammatory effects. However, these effects are also likely to be responsible for the suppressed immunity that makes elite athletes more susceptible to infections. The anti-inflammatory effects of regular exercise may be mediated via both a reduction in visceral fat mass (with a subsequent decreased release of adipokines) and the induction of an anti-inflammatory environment with each bout of exercise. In this Review, we focus on the known mechanisms by which exercise - both acute and chronic - exerts its anti-inflammatory effects, and we discuss the implications of these effects for the prevention and treatment of disease.

The Metabolically Benign and Malignant Fatty Liver

The epidemics of the major metabolic diseases type 2 diabetes and cardiovascular disease are increasing worldwide and much effort is being undertaken to understand the pathogenesis of these conditions. Both type 2 diabetes and cardiovascular disease share insulin resistance as a common and important risk factor in their natural history. It is now widely accepted that organ cross talk harbors many critical clues that help to better understand the pathogenesis of insulin resistance. In this respect, several studies recently showed that not the increase in body fat mass per se, but the accumulation of fat in the visceral cavity and particularly in the liver, which are conditions commonly accompanied by inflammatory processes, are responsible for the genesis of insulin resistance (1–4). ### Prevalence, pathogenesis, and progression. The prevalence of nonalcoholic fatty liver disease (NAFLD) has increased worldwide, affecting more than 25% of adults. In obese people and in patients with type 2 diabetes, the prevalence has increased to more than 70%. In obese children, NAFLD is found in 23–53% (5). Several mechanisms lead to fatty liver. First, expansion and inflammation of adipose tissue results in adipose insulin resistance and increased lipolysis and thereby in an elevated flux of free fatty acids into the liver. Second, an impaired hepatic fatty acid oxidation and a decrease in proteins inducing lipid oxidation, e.g., adiponectin, results in further accumulation of fat within the liver. Third, increased hepatic de novo lipogenesis driven by hyperinsulinemia and increased carbohydrate intake elevate the hepatic fat content. Fourth, impaired VLDL secretion exacerbates this process. This stage is often referred to as benign steatosis. The overwhelming of lipid oxidation capacity eventually occurs resulting in the generation of reactive oxidative species (ROS), gut-derived signals (e.g., bacterial endotoxins, short-chain fatty acids), inflammatory cytokines, and an imbalanced release of adipokines that then may result …

Inflammatory Phenotyping Identifies CD11d as a Gene Markedly Induced in White Adipose Tissue in Obese Rodents and Women

In severe obesity, white adipose tissue (WAT) inflammation and macrophage infiltration are thought to contribute to WAT and whole-body insulin resistance. Specific players involved in triggering and maintaining inflammation (i.e. those regulating adipokine release and WAT macrophage recruitment, retention, or function) remain to be fully elaborated, and the degree to which moderate obesity promotes WAT inflammation remains to be clarified further. Therefore, we characterized adiposity and metabolic phenotypes in adult male C57BL/6J mice fed differing levels of dietary fat (10, 45, and 60% of energy) for 12 wk, concurrent with determinations of WAT inflammation markers and mRNA expression of leukocyte-derived integrins (CD11b, CD11c, CD11d) involved in macrophage extravasation and tissue macrophage homing/retention. As expected, a lard-based, very high-fat diet (60% energy) significantly increased adiposity and glucose intolerance compared with 10% fat-fed controls, coincident with higher retroperitoneal (RP) WAT transcript levels for proinflammatory factors and macrophage markers, including TNFa and CD68 mRNA, which were ~3- and ~15-fold of control levels, respectively (P < 0.001). Mice fed the 45% fat diet had more moderate obesity, less glucose intolerance, and lower WAT macrophage/inflammatory marker mRNA abundances compared with 60% fat-fed mice; TNFa and CD68 mRNA levels were ~2- and ~5-fold of control levels (P < 0.01). Relative WAT expression of CD11d was massively induced by obesity to an extent greater than any other inflammatory marker (to >300-fold of controls in the 45 and 60% fat groups) (P < 0.0001) and this induction was WAT specific. Because we found that CD11d expression also increased in RP-WAT of Zucker obese rats and in the subcutaneous WAT of obese adult women, this appears to be a common feature of obesity. Observed correlations of WAT macrophage transcript marker abundances with body weight in lean to modestly obese mice raises an interesting possibility that the activities of at least some WAT macrophages are closely linked to the normal adipose remodeling that is a requisite for changes in WAT energy storage capacity.

Effects of nevirapine and efavirenz on human adipocyte differentiation, gene expression, and release of adipokines and cytokines

The non-nucleoside reverse transcriptase inhibitors (NNRTIs) nevirapine and efavirenz are drugs of choice for initial antiretroviral treatment for HIV-1 infection. Although NNRTIs have not traditionally been associated with the appearance of adipose alterations, recent data suggest that efavirenz may contribute to adipose tissue alterations in antiretroviral-treated patients, consistent with its ability to impair differentiation of adipocytes in cell cultures. No such effects have been reported for nevirapine, the other most commonly used NNRTI. In this study, we determined the effects of nevirapine on differentiation, gene expression and release of regulatory proteins (adipokines and cytokines) in differentiating human adipocytes, and compared them with those of efavirenz. Efavirenz caused a dose-dependent repression of adipocyte differentiation that was associated with down-regulation of the master adipogenesis regulator genes SREBP-1, PPARγ and C/EBPα, and their target genes encoding lipoprotein lipase, leptin and adiponectin, which are key proteins in adipocyte function. In contrast, nevirapine does not affect adipogenesis and causes a modest but significant coordinate increase in the expression of SREBP-1, PPARγ and C/EBPα and their target genes only at a concentration of 20 μM. Whereas efavirenz caused a significant increase in the release of pro-inflammatory cytokines (interleukin [IL]-8, IL-6, monocyte chemoattractant protein-1), plasminogen activator inhibitor type-1 and hepatocyte growth factor (HGF), nevirapine either had no effect on these factors or decreased their release (IL-6 and HGF). Nevirapine significantly increased adiponectin release, whereas efavirenz strongly repressed it. Moreover, nevirapine inhibited preadipocyte endogenous reverse transcriptase activity, whereas efavirenz did not alter it. It is concluded that, in contrast with the profound anti-adipogenic and pro-inflammatory response elicited by efavirenz, nevirapine does not impair adipogenesis.

Hiv-1 Tat Protein Impairs Adipogenesis and Induces the Expression and Secretion of Proinflammatory Cytokines in Human Sgbs Adipocytes

HIV-1 Tat protein has been shown to play multiple roles in the pathogenesis of AIDS; however, there is no information currently available on its effects on adipose tissue alterations. We have studied the effects of Tat on SGBS adipocytes to gain insight on its role on the development of lipodystrophy. SGBS preadipocytes were exposed to Tat during and after differentiation. Acquisition of adipocyte morphology, expression of gene markers of adipogenesis and inflammation, release of adipokines and cytokines to the medium, and glucose uptake were measured. The action of Tat on tumour necrosis factor (TNF)-α-regulated messenger RNA expression was determined in differentiated adipocytes. The capacity of rosiglitazone, resveratrol and parthenolide to influence the action of Tat was also assessed. Tat treatment reduced the number of SGBS preadipocytes that acquired adipocyte morphology. It also led to repression of adipogenic gene expression and induced the coordinate expression and release of proinflammatory cytokines in human adipose cells. Moreover, combined treatment with Tat and TNF-α produced an additive effect on the repression of adipocyte genes. The observed effects of Tat on gene transcription in adipocytes were due, in part, to TNF-α that was secreted as a consequence of intracellular exposure to Tat. Tat impairs adipogenesis in human SGBS preadipocytes and increases the expression and release of proinflammatory cytokines. Positive crosstalk between Tat and TNF-α contributes to the anti-adipogenic and proinflammatory effects. HIV-1 Tat protein may play a role in the adipose tissue alterations that ultimately lead to lipoatrophy and systemic metabolic disturbances observed in HIV-1-infected patients.

The infrapatellar fat pad of osteoarthritic patients has an inflammatory phenotype

Background and objectivesObesity is a risk factor for the development of osteoarthritis (OA) in hands and knees. It has become apparent during the last years that adipose tissue can secrete...

The infrapatellar fat pad of patients with osteoarthritis has an inflammatory phenotype

ObjectivesObesity is a risk factor for the development of osteoarthritis (OA) in hands and knees. Adipose tissue can secrete different adipokines with powerful immunomodulatory effects. The infrapatellar fat pad (IFP)...

Effects of Obesity and Subsequent Weight Reduction on Left Ventricular Function

Obesity is reaching epidemic proportions in the United States. Obesity adversely affects the circulatory system with resultant endothelial dysfunction, which promotes systemic hypertension, coronary artery disease, and vascular calcification. It is believed that the release of adipokines is responsible for this effect. In addition, obesity causes intrinsic changes in the heart including an increase in left ventricular (LV) mass, LV hypertrophy, LV dilatation, left atrial dilatation, and diastolic, as well as systolic dysfunction in some cases. The combination of increased adipose cells and an increase lean muscle mass in obese patients results in high cardiac output and an accompanying increased circulating volume leading to these adaptive changes. Weight loss by means of caloric restriction or surgery results in favorable hemodynamic changes referred to as "reverse remodeling." Regression of LV mass and chamber size has been shown universally. However, some studies have failed to reveal improvement in diastolic function possibly because of confounders such as nutritional deficiency that may occur after weight loss surgery. Some evidence seems to suggest that the greatest regression of LV mass and LV hypertrophy may occur when weight loss is combined with beta-adrenergic blocker therapy (in those who have an indication for the drug) when compared with other antihypertensive drugs versus weight loss alone.

Different Adipose Depots: Their Role in the Development of Metabolic Syndrome and Mitochondrial Response to Hypolipidemic Agents

Adipose tissue metabolism is closely linked to insulin resistance, and differential fat distributions are associated with disorders like hypertension, diabetes, and cardiovascular disease. Adipose tissues vary in their impact on metabolic risk due to diverse gene expression profiles, leading to differences in lipolysis and in the production and release of adipokines and cytokines, thereby affecting the function of other tissues. In this paper, the roles of the various adipose tissues in obesity are summarized, with particular focus on mitochondrial function. In addition, we discuss how a functionally mitochondrial-targeted compound, the modified fatty acid tetradecylthioacetic acid (TTA), can influence mitochondrial function and decrease the size of specific fat depots.

Fatty Acids and Hypoxia Stimulate the Expression and Secretion of the Adipokine ANGPTL4 (Angiopoietin-Like Protein 4/ Fasting-Induced Adipose Factor) by Human Adipocytes

Background/Aims: Hypoxia occurs in white adipose tissue in obesity, modulating the expression and release of specific inflammation-related adipokines. ANGPTL4 (angiopoietin-like protein 4/fasting-induced adipose factor), which is implicated in angiogenesis, lipid metabolism and glucose homeostasis, is a major hypoxia-sensitive gene; recent studies indicate that ANGPTL4 expression is also regulated by fatty acids. We have examined the effects of hypoxia and fatty acids, alone and together, on the expression and release of ANGPTL4 by human adipocytes. Methods: Human adipocytes were differentiated and incubated with fatty acids (250 µM) in normoxia (21% O₂) or hypoxia (1% O₂). ANGPTL4 mRNA was measured by real-time PCR and the protein in the medium determined by ELISA. Results: In normoxia, ANGPTL4 gene expression was upregulated by palmitic, oleic, arachidonic and eicosapentaenoic acids, and ANGPTL4 release was increased. In contrast, there was no effect of lauric or myristic acids. Hypoxia alone increased the expression and secretion of ANGPTL4, and lauric, myristic, arachidonic and eicosapentaenoic acids each further increased expression and release in hypoxic adipocytes. Conclusion: The expression and secretion of ANGPTL4 by human adipocytes is upregulated by both hypoxia and fatty acids. The stimulatory effect of fatty acids on ANGPTL4 production is augmented under hypoxic conditions.

Differential Effects of Efavirenz and Lopinavir/Ritonavir on Human Adipocyte Differentiation, Gene Expression and Release of Adipokines and Pro-Inflammatory Cytokines.

In the present study, a comparative assessment of the effects of efavirenz (EFV) and lopinavir/ritonavir (LPV/r; 4:1) on human adipocytes in culture has been performed. Human pre-adipocytes were treated with EFV or LPV/r during or after adipogenic differentiation. Acquisition of adipocyte morphology, expression of gene markers of mitochondrial toxicity, adipogenesis and inflammation, and release of adipokines and cytokines to the medium were measured. Results indicated that EFV and LPV/r impaired adipocyte differentiation in association with a reduction in transcript levels for adipogenic differentiation genes (adiponectin, lipoprotein lipase, leptin) and master regulators of adipogenesis (PPAR, C/EBP). The effects were greater with EFV than LPV/r. Both LPV/r and EFV induced increases in monocytechemoattactant protein-1 (MCP-1) mRNA levels, but the effect was greater with EFV. Similarly, the release of proinflammatory cytokines and other inflammation-related molecules (interleukins 6 and 8, MCP-1, PAI-1) was enhanced to a much higher degree by EFV than by LPV/r. Adiponectin and leptin release by adipocytes was reduced by both drugs, although to a higher extent by EFV. Neither drug affected mitochondrial DNA levels, transcripts encoding mitochondrial proteins or lactate release by adipocytes. In previously differentiated adipocytes, EFV caused a significant reduction in PPARγ and adiponectin expression, whereas LPV/r did not. We conclude that both EFV and LPV/r impair human adipogenesis, reduce adipokine release and increase the expression and release of inflammation-related cytokines, but the overall effects are greater with EFV. These findings may have implications for the pathogenesis of HIV-1-associated lipodystrophy and the development of HIV-1 therapies.