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Given the unprecedented global pandemic of obesity, a better understanding of the etiology of adiposity will be necessary to ensure effective management of obesity and related complications. Among the various potential factors contributing to obesity, endoplasmic reticulum (ER) stress refers to a state of excessive protein unfolding or misfolding that is commonly found in metabolic diseases including diabetes mellitus, insulin resistance (IR), and non-alcoholic fatty liver disease, although its role in obesogenesis remains controversial. ER stress is thought to drive adiposity by dampening energy expenditure, making ER stress a likely therapeutic target for the management of obesity. We summarize the role of ER stress and the ER stress response in the onset and development of obesity, and discuss the underlying mechanisms involved with a view to identifying novel therapeutic strategies for obesity prevention and management.

The neuropeptide urocortin 3 (UCN3) has a beneficial effect on metabolic disorders, such as obesity, diabetes, and cardiovascular disease. It has been reported that UCN3 regulates insulin secretion and is dysregulated with increasing severity of obesity and diabetes. However, its function in the adipose tissue is unclear. We investigated the overexpression of UCN3 in 3T3-L1 preadipocytes and differentiated adipocytes and its effects on heat shock response, ER stress, inflammatory markers, and glucose uptake in the presence of stress-inducing concentrations of palmitic acid (PA). UCN3 overexpression significantly downregulated heat shock proteins (HSP60, HSP72 and HSP90) and ER stress response markers (GRP78, PERK, ATF6, and IRE1α) and attenuated inflammation (TNFα) and apoptosis (CHOP). Moreover, enhanced glucose uptake was observed in both preadipocytes and mature adipocytes, which is associated with upregulated phosphorylation of AKT and ERK but reduced p-JNK. Moderate effects of UCN3 overexpression were also observed in the presence of 400 μM of PA, and macrophage conditioned medium dramatically decreased the UCN3 mRNA levels in differentiated 3T3-L1 cells. In conclusion, the beneficial effects of UCN3 in adipocytes are reflected, at least partially, by the improvement in cellular stress response and glucose uptake and attenuation of inflammation and apoptosis.

Spexin is a novel neuropeptide playing an emerging role in metabolic diseases such as obesity and diabetes via involvement in energy homeostasis and food intake. The present study investigated the effects of obesity and type 2 diabetes (T2D) on circulating levels of spexin and its modulation by physical exercise. Normal-weight (n = 50) and obese adults with and without T2D (n = 69 and n = 66, respectively) were enrolled in the study. A subgroup of obese participants (n = 47) underwent a supervised 3-month exercise programme. Plasma spexin levels were measured by ELISA and correlated with various markers. Plasma spexin levels decreased in obese participants with or without T2D compared with those of normal-weight participants (0.43 ± 0.11, 0.44 ± 0.12 and 0.61 ± 0.23 ng/ml, respectively; P P P 2 max) with a concomitant improvement in metabolic profile. In conclusion, plasma spexin levels may be an indicator of response to physical exercise.

Objective The corticotropin-releasing factor neuropeptides (corticotropin-releasing hormone [CRH] and urocortin [UCN]-1,2,3) and spexin contribute to the regulation of energy balance and inhibit food intake in mammals. However, the status of these neuropeptides in children with overweight has yet to be elucidated. This study investigated the effect of increased body weight on the circulating levels of these neuropeptides. Methods A total of 120 children with a mean age of 12 years were enrolled in the study. Blood samples were collected to assess the circulating levels of neuropeptides and were correlated with various anthropometric, clinical, and metabolic markers. Results Plasma levels of UCNs were altered in children with overweight but less so in those with obesity. Furthermore, the expression pattern of UCN1 was opposite to that of UCN2 and UCN3, which suggests a compensatory effect. However, no significant effect of overweight and obesity was observed on CRH and spexin levels. Finally, UCN3 independently associated with circulating zinc-alpha-2-glycoprotein and UCN2 levels, whereas UCN1 was strongly predicted by TNF alpha levels. Conclusions Significant changes in neuropeptide levels were primarily observed in children with overweight and were attenuated with increased obesity. This suggests the presence of a compensatory mechanism for neuropeptides to curb the progression of obesity.

The corticotropin-releasing hormone (CRH) and urocortins (UCNs) have been implicated in energy homeostasis and the cellular stress response. However, the expression of these neuropeptides in children remains unclear. Therefore, we determined the impact of obesity on their expression in 40 children who were normal weight, overweight, and had obesity. Peripheral blood mononuclear cells (PBMCs) and plasma were used to assess the expression of neuropeptides. THP1 cells were treated with 25 mM glucose and 200 µM palmitate, and gene expression was measured by real-time polymerase chain reaction (RT-PCR). Transcript levels of neuropeptides were decreased in PBMCs from children with increased body mass index as indicated by a significant decrease in UCN1, UCN3, and CRH mRNA in overweight and obese children. UCN3 mRNA expression was strongly correlated with UCN1, UCN2, and CRH. Exposure of THP1 cells to palmitate or a combination of high glucose and palmitate for 24 h increased CRH, UCN2, and UCN3 mRNA expression with concomitant increased levels of inflammatory and endoplasmic reticulum stress markers, suggesting a crosstalk between these neuropeptides and the cellular stress response. The differential impairment of the transcript levels of CRH and UCNs in PBMCs from overweight and obese children highlights their involvement in obesity-related metabolic and cellular stress.

Background Angiopoietin-like proteins (ANGPTL), primarily 3, 4, and 8, play a major role in maintaining energy homeostasis by regulating triglyceride metabolism. This study evaluated the level of ANGPTL3, 4, and 8 in the liver, brown adipose tissue (BAT), and subcutaneous white adipose tissue (SAT) of mice maintained under acute and chronic cold conditions. Methods C57BL/6J mice were exposed to cold temperature (4 °C) for 10 days with food provided ad libitum. Animal tissues were harvested at Day 0 (Control group, n = 5) and Days 1, 3, 5, and 10 (cold treatment groups, n = 10 per group). The expression levels of various genes were measured in the liver, SAT, and BAT. ANGPTL3, 4, and 8 expressions were measured in the liver. ANGPTL4, 8, and genes involved in browning and lipid metabolism [uncoupling protein 1 (UCP1), lipoprotein lipase (LPL), and adipose triglyceride lipase (ATGL)] were measured in SAT and BAT. Western blotting (WB) analysis and immunohistochemistry (IHC) were performed to confirm ANGPTL8 expression in these tissues. Results The expressions of ANGPTL3 and 8 mRNA were significantly reduced in mouse liver tissues after cold treatment (P P ANGPTL8 gene expression exhibited over a 5-fold increase. Similarly, UCP1 gene expression was also significantly increased in SAT. The mRNA levels of LPL and ATGL showed an initial increase followed by a gradual decrease with an increase in the days of cold exposure. ANGPTL8 protein overexpression was further confirmed by WB and IHC. Conclusions This study shows that exposure to acute and chronic cold treatment results in the differential expression of ANGPTL proteins in the liver and adipose tissues (SAT and BAT). The results show a significant reduction in ANGPTL4 in BAT, which is linked to improved thermogenesis in response to acute cold exposure. ANGPTL8 was activated under acute and chronic cold conditions in SAT, suggesting that it is involved in regulating lipolysis and enhancing SAT browning.

Background. Cardiovascular disease (CVD) risks persist in patients despite the use of conventional treatments. This might be due to chronic inflammation as reflected in epidemiological studies associating circulating low-grade inflammatory markers with CVD recurrent events. Here, we explored this potential link by assessing plasma dual-specificity phosphatase 1 (DUSP1) levels and comparing them to high-sensitivity CRP (hsCRP) and oxidized low-density lipoprotein (oxLDL) levels and their associations to conventional CVD risk factors in confirmed CVD patients.Methods. Human adults with reported CVD (n=207) and controls (n=70) living in Kuwait were used in this study. Anthropometric and classical biochemical parameters were determined. Plasma levels of DUSP1, oxLDL, and hsCRP were measured using human enzyme-linked immunosorbent assay kits.Results. DUSP1 and hsCRP plasma levels and their least square means were higher in CVD cases, while oxLDL plasma levels were lower (p<0.05). Multivariate logistic regression analysis showed that DUSP1 and hsCRP are independently associated with CVD in the studied population, as reflected by 2-fold and 1.5-fold increased risks with increased levels of DUSP1 and hsCRP, respectively. In our study, DUSP1 levels were found to be associated with CVD despite statin treatment and diabetes status (p<0.05), whereas hsCRP mainly correlated with obesity markers.Conclusions. Circulating DUSP1 might be a predictor of chronic subclinical inflammation and residual risk in CVD patients, whereas our data suggest that the association between hsCRP and CVD is largely accounted for adiposity risk factors.

Background The hepatokine fetuin-A is linked to obesity and type 2 diabetes, but its presence and expression in adipose tissue remain unclear. In this study, we aimed to assess the circulating levels of fetuin-A and its expression in subcutaneous adipose tissue (SAT) from diabetic and non-diabetic obese subjects and their modulation by exercise. Methods SAT and blood were obtained from adults obese (diabetic, n=118 and non-diabetic, n=166) before and after a 3-month exercise program (diabetic, n=40 and non-diabetic, n=36, respectively). Plasma fetuin-A was assayed using ELISA. The presence and expression of fetuin-A in SAT, peripheral blood mononuclear cells (PBMCs) and cell lines (3T3-L1, THP-1, HepG2, RAW 264.7) were analysed using confocal microscopy, immunoblotting and qRT-PCR. Results Plasma fetuin-A level did not significantly differ between diabetic and non-diabetic obese subjects. However, when the non-diabetic group was divided into metabolically healthy and unhealthy phenotypes, significantly higher fetuin-A level was observed in the unhealthy sub-group. Circulating fetuin-A was mainly associated with glycaemic markers. In SAT, fetuin-A protein level was significantly higher in the diabetic obese subjects but its mRNA was not detected. Similarly, fetuin-A protein was detected in PBMCs, but its mRNA was not. In line with this, the use of various cell lines and culture media indicated that the presence of fetuin-A in SAT and PBMCs was due to its uptake from circulation rather than its endogenous expression. Finally, physical exercise decreased fetuin-A levels in both plasma and SAT in both groups. Conclusions Fetuin-A levels increased in association with diabetes in SAT but not in circulation in the obese subjects. Moreover, physical exercise decreased fetuin-A level. Fetuin-A potentially acts as a hepatokine taken up by other tissues, such as adipose tissue. Electronic supplementary material The online version of this article (10.1186/s12944-018-0919-x) contains supplementary material, which is available to authorized users.

Background It is well known that Angiopoietin like protein (ANGPTL) mainly 3, 4 and 8 play a major role in maintaining energy homeostasis by regulating lipoprotein lipase (LPL) activity, which is a key regulator of triglyceride (TG) metabolism. Our aim is to evaluate the level of ANGPTL3, 4 and 8 in mice maintained under cold conditions in the liver, brown adipose tissue (BAT), and white adipose tissue (WAT). Methods C57BL/6J mice were exposed to cold temperature at 4˚C over a period of ten days with food given ad libitum. Animal tissues were harvested at days 0, 1, 3, 5, and 10 (cold treatment groups, n = 10 in each group, control, n = 5). Liver, subcutaneous adipose tissue (SAT), and BAT were used to investigate the expression level of different genes. ANGPTL3, 4 and 8 genes expression were measured in liver. ANGPTL4, 8 and UCP1 were measured in SAT and BAT. Results ANGPTL 3 and 8 gene expression levels were significantly reduced in mice liver tissues after cold treatment (P-value

Epoxide hydrolase 2 (EPHX2) is an emerging therapeutic target in several immunometabolic disorders. EPHX2 metabolizes anti-inflammatory epoxyeicosatrienoic acids into pro-inflammatory diols. The contribution of EPHX2 activity to human obesity remains unexplored. We compared the expression of EPHX2 between lean and obese humans (n = 20 each) in subcutaneous adipose tissue (SAT) and peripheral blood mononuclear cells (PBMCs) using RT-PCR, Western Blot analysis, immunohistochemistry, and confocal microscopy before and after a 3-month physical activity regimen. We also assessed EPHX2 levels during preadipocyte differentiation in humans and mice. EPHX2 mRNA and protein expression were significantly elevated in obese subjects, with concomitant elevated endoplasmic reticulum (ER) stress components (the 78-kDa glucose-regulated protein, GRP78, and the Activating transcription factor 6, ATF6) and inflammatory markers (Tumor necrosis factor-&alpha, TNF&alpha, and Interleukin 6, IL6) as compared to controls (p &lt, 0.05). EPHX2 mRNA levels strongly correlated with adiposity markers. In obese individuals, physical activity attenuated EPHX2 expression levels in both the SAT and PBMCs, with a parallel decrease in ER stress and inflammation markers. EPHX2 expression was also elevated during differentiation of both human primary and 3T3-L1 mouse preadipocytes. Mediators of cellular stress (palmitate, homocysteine, and macrophage culture medium) also increased EPHX2 expression in 3T3-L1 preadipocytes. Our findings suggest that EPHX2 upregulation is linked to ER stress in adiposity and that physical activity may attenuate metabolic stress by reducing EPHX2 expression.

Fetuin-A (Fet-A) was one of the first hepatokines to be reportedly linked to metabolic diseases. Fet-A was also suggested to be an adipokine, but its expression in the adipose tissue remains debatable. Here we compared the expression of Fet-A between human and mice adipose tissue biopsies as well as among human subcutaneous tissue and visceral adipose tissue primary cells, and mouse 3 T3-L1 cells at various stages of differentiation. Fet-A was expressed in mice biopsies and cells but not in human biopsies and cells, except in visceral adipose tissue primary cells following differentiation. Although the marginal expression of Fet-A in human visceral adipose tissue, a major contribution of Fet-A expression in human adipose tissue to systemic Fet-A levels is discounted, but it could indicate specific local Fet-A action in the visceral adipose tissue.

Lipotoxicity, an important factor in the pathogenesis of diabetes, leads to defective β-cell proliferation and increased apoptosis. Glucagon-like peptide-1 (GLP-1) analogs, which are used to treat type 2 diabetes, reduce endoplasmic reticulum stress and inflammation in pancreatic β-cells and improve their survival. However, their effects on the heat shock response (HSR) have not been elucidated yet. We investigated whether the GLP-1 analog exendin-4 exerts its protective effect by modulating the HSR and mitogen-activated protein kinases (MAPKs) in BTC-6 mouse pancreatic cells under palmitic acid (PA) stress. Expression patterns were analyzed using mass spectrometry, Western blotting, and qRT-PCR in the presence of 250 or 400 μM PA and 100 nM exendin-4. Additionally, we measured MAPK expression and phosphorylation using qRT-PCR and Western blotting, respectively. Upregulation of heat shock protein (HSP), notably HSP72, in the presence of PA, was attenuated by exendin-4. Despite the absence of global effects on the HSR system, exendin-4 attenuated the expression of other non-classical HSPs (GRP94, DNAJA1, and DNAJB6) in the presence of PA. Regarding MAPKs, only extracellular signal-regulated kinase (ERK) phosphorylation was highly increased by exendin-4 in both the presence and absence of PA. Furthermore, exendin-4 significantly alleviated PA-induced cell death, which was further confirmed with proteomics analysis where key cellular functions, including cellular growth, assembly, and organization, were improved by exendin-4 treatment. Thus, our results expand the protective role of GLP-1 analogs to include other cellular mechanisms involved in restoring normal β-cell homeostasis.

Background and objectives Perturbation of the endoplasmic reticulum (ER) homeostasis has emerged as one of the prominent features of obesity and diabetes. This occurs when the adaptive unfolded protein response (UPR) fails to restore ER function in key metabolic tissues. We previously reported increased inflammation and impaired heat shock response (HSR) in obese human subjects that were restored by physical exercise. Here, we investigated the status of ER stress chaperone; glucose-regulated protein 78 (GRP78) and its downstream UPR pathways in human obese, and their modulation by a supervised 3-month physical exercise. Methods Subcutaneous adipose tissue (SAT) and blood samples were collected from non-diabetic adult human lean (n = 40) and obese (n = 40, at baseline and after 3 months of physical exercise). Transcriptomic profiling was used as a primary screen to identify differentially expressed genes and it was carried out on SAT samples using the UPR RT 2 Profiler PCR Array. Conventional RT-PCR, immunohistochemistry, immunofluorescence, Western blot and ELISA were used to validate the transcriptomic data. Correlation analyses with the physical, clinical and biochemical outcomes were performed using Pearson's rank correlation coefficient. Results Levels of GRP78 and its three downstream UPR arms; activating transcription factor-6 (ATF6), inositol-requiring enzyme-1α (IRE1α) and protein kinase RNA-like endoplasmic reticulum kinase (PERK) were increased in obese subjects. More interestingly, higher levels of circulating GRP78 protein were found in obese compared to lean subjects which correlated negatively with maximum oxygen uptake (V O2 Max ) but positively with high-sensitivity C-reactive protein (hsCRP) and obesity indicators such as BMI, percentage body fat (PBF) and waist circumference. GRP78 increased secretion in obese was further confirmed in vitro using 3T3-L1 preadipocyte cells under ER stress. Finally, we showed that physical exercise significantly attenuated the expression and release of GRP78 with a concomitant reduction in the phosphorylation of IRE1α and eukaryotic initiation factor-2α (eIF2α). Conclusion Our results suggest that physical exercise alleviates ER stress in human obese through attenuation of GRP78 signaling network.

Purpose : Glucagon-like peptide-1 (GLP-1) analogues reduce ER stress and inflammation in key metabolic organs, including the liver. However, their effects on heat shock response (HSR) and mitogen-activated protein kinases (MAPKs) have not yet been elucidated. In the present study, we investigated whether the GLP-1 analogue, exendin-4, triggers the expression of HSR and increases MAPK activity under metabolic stress. Experimental design : The effects of exendin-4 in the presence or absence of palmitic acid (PA; 400 μM) or glucose (30 mM) in the HepG2 liver cell line were assessed using Western blots, quantitative real-time PCR and label-free proteomics. Results : Heat shock proteins (HSP60, HSP72, HSP90 and GRP78) and other chaperones were not significantly affected by exendin-4 under the conditions tested. In contrast, the presence of exendin-4 alone increased the MAPK phosphorylation levels (JNK, ERK1/2 and p38). For short incubation periods, in the presence of PA or glucose, treatment with exendin-4 exhibited limited effects but significantly attenuated MAPK phosphorylation after a 24-h incubation. Interestingly, canonical signalling pathways, such as EIF2, ILK, PKA and Rho, were modulated by exendin-4. Conclusion and clinical relevance : Identifying new pathways modulated by GLP-1 analogues will provide further insights into their benefits beyond their currently recognized roles in glycaemic control, such as MAPK activity, energy homeostasis and body weight decrease. This article is protected by copyright. All rights reserved

Differential expression of HSP60 and exercise effects on its levels in Obese Diabetic and non-Diabetic humansSina Kavalakatt, Abdelkrim Khadir and Ali TissResearch Division, Dasman Diabetes Institute, Kuwait Background: Obesity is a growing epidemic worldwide and is characterized by low grade inflammation and impaired heat shock response (HSR). Sedentary lifestyle and high caloric intake are major contributors to obesity, diabetes and its complications. Physical activity is known to improve overall health in many chronic diseases by modulating metabolic stress pathways including HSR. However, limited data exist on these mechanisms in adipose tissue. HSP60, a member of HSR, interestingly can induce both pro-inflammatory and anti-inflammatory markers suggesting its role in modulating inflammation in metabolic diseases. We recently reported that, HSP60 acting as a chaperonin for proteins in the mitochondrion, was increased in human obese. However, the expression levels of HSP60 in obese diabetic are yet to be investigated.Aim: Assess the expression levels of HSP60 in diabetic obese as non-diabetic humans and its correlation with inflammatory and metabolic markers as well as its modulation by physical exercise. Methods:Adult male and female subjects consisting of non-diabetic (138) and diabetic (92) obese were recruited for the study. Subjects were enrolled for a 3-month supervised exercise program. Subcutaneous adipose tissue (SAT) biopsies and venous peripheral blood were collected before and after exercise. Anthropometric measurements and blood biochemistry were done at baseline and after exercise. Plasma levels of inflammatory and metabolic markers were measured using Bioplex-200 system. The expression levels of Hsp60 was studied using immunohistochemistry and confocal microscopy and then validated using Real Time-PCR. Circulating levels of Hsp60 and its auto-antibodies were estimated using ELISA. All statistical analyses were done using SAS version 9.2.Results: In this study, the expression levels of HSP60 were significantly decreased in SAT of diabetic obese patients when compared to non-diabetic obese. This downregulation was concomitant with increased levels of IL6 and TNFu03b1 inflammatory markers in SAT of diabetic obese. HSP60 is known to be released under inflammatory stress conditions. In our study, there was no difference in the levels of circulating HSP60 and its auto-antibody between these two groups. Our 3-months exercise protocol increased significantly HSP60 expression levels in SAT of diabetic obese along with a decreased inflammation. In non-diabetic obese the same exercise protocol decreased both HSP60 and inflammatory markers TNF and IL6, suggesting a differential exercise effect in the two groups.Discussion:The role of the HSP's in the progression of obesity and diabetes is not yet fully elucidated. Our earlier data has demonstrated increased expression of major HSPs including Hsp60 in obese non-diabetic subjects suggesting that metabolic stress of obesity triggers upregulation of HSR. In contrast, our current study shows reduction in HSP60 expression in diabesity whereas exercise increase its expression along with reduced inflammation. Interestingly, the effects of physical exercise on HSP60 levels in diabetic and non-diabetic obese were opposite. This might reflect a specific adaptive response to exercise according to the metabolic stress status. Therefore, enhancing HSR defense system through exercise might have a beneficial impact on future approaches to diabetes prevention and treatment.

Background ANGPTL8 also called betatrophin is a regulator of lipid metabolism through its interaction with ANGPTL3. It has also been suggested to play a role in insulin resistance and beta-cell proliferation. Based on its function, we hypothesized that ANGPTL8 will play a role in Metabolic Syndrome (MetS). To test this hypothesis we designed this study to measure ANGPTL8 level in subjects with MetS as well as its association with high sensitivity C-reactive protein (HsCRP) level in humans. Methods ANGPTL8 level was measured using ELISA in subjects with MetS as well as their controls, a total of 1735 subjects were enrolled. HsCRP was also measured and its association with ANGPTL8 was examined. Results ANGPTL8 level was higher in subjects with MetS 1140.6 (171.9–11736.1) pg/mL compared to 710.5 (59.5–11597.2) pg/mL in the controls. Higher levels of ANGPTL8 were also observed with the sequential increase in the number of MetS components (p value =

Background. The impact of gender difference on the association between metabolic stress and cardiovascular disease (CVD) remains unclear. We have investigated, for the first time, the gender effect on the oxidative and inflammatory stress responses and assessed their correlation with classical cardiometabolites in Arab population.Methods. A total of 378 adult Arab participants (193 females) were enrolled in this cross-sectional study. Plasma levels of CRP, IL-6, IL-8, TNF-α, ROS, TBARs, and PON1 were measured and correlated with anthropometric and cardiometabolite parameters of the study population.Results. Compared to females, males had significantly higher FBG, HbA1c, TG, and blood pressure but lower BMI, TC, and HDL (P P α(P α, IL-6, and ROS were associated with central obesity but not general obesity.Conclusion. Inflammation and oxidative stress contribution to CVD risk in Arab population linked to gender and this risk is better reflected by central obesity. Arab females might be at risk of CVD complications due to increased oxidative stress.

Chronic low-grade inflammation and dysregulation of the stress defense system are cardinal features of obesity, a major risk factor for the development of insulin resistance and diabetes. Dual-specificity protein phosphatase 1 (DUSP1), known also as MAP kinase phosphatase 1 (MKP1), is implicated in metabolism and energy expenditure. Mice lacking DUSP1 are resistant to high-fat diet-induced obesity. However, the expression of DUSP1 has not been investigated in human obesity. In the current study, we compared the expression pattern of DUSP1 between lean and obese nondiabetic human subjects using subcutaneous adipose tissue (SAT) and peripheral blood mononuclear cells (PBMCs). The levels of DUSP1 mRNA and protein were significantly increased in obese subjects with concomitant decrease in the phosphorylation of p38 MAPK (p-p38 MAPK) and PGC-1α and an increase in the levels of phospho-JNK (p-JNK) and phospho-ERK (p-ERK). Moreover, obese subjects had higher levels of circulating DUSP1 protein that correlated positively with various obesity indicators, triglycerides, glucagon, insulin, leptin, and PAI-1 ( P < 0.05) but negatively with V̇o2max and high-density lipoprotein ( P < 0.05). The observation that DUSP1 was overexpressed in obese subjects prompted us to investigate whether physical exercise could reduce its expression. In this study, we report for the first time that physical exercise significantly attenuated the expression of DUSP1 in both the SAT and PBMCs, with a parallel increase in the expression of PGC-1α and a reduction in the levels of p-JNK and p-ERK along with attenuated inflammatory response. Collectively, our data suggest that DUSP1 upregulation is strongly linked to adiposity and that physical exercise modulates its expression. This gives further evidence that exercise might be useful as a strategy for managing obesity and preventing its associated complications.

Chronic low-grade inflammation and uncontrolled metabolic stress response are cardinal features of obesity; a major risk factor for the development diabetes. Dual specificity protein phosphatase 1 (DUSP1) is implicated in metabolism and energy expenditure. Mice lacking DUSP1 are resistant to high fat diet-induced obesity. However, the expression of DUSP1 has not been investigated in human obesity. In the current study, we compared the expression pattern of DUSP1 between lean and obese non-diabetic human subjects using subcutaneous adipose tissue and peripheral blood mononuclear cells. The levels of DUSP1 mRNA and protein were significantly increased in obese subjects with concomitant decrease in the phosphorylation of p38 MAPK and PGC-1α and an increase in the levels of phospho-JNK and phospho-ERK. Moreover, obese subjects had higher levels of circulating DUSP1 protein that correlated positively with various obesity indicators, triglycerides, glucagon, insulin, leptin and PAI-1 (P

Sedentary lifestyle and excessive energy intake are prominent contributors to obesity; a major risk factors for the development of insulin resistance, type 2 diabetes and cardiovascular diseases. Elucidating the molecular mechanisms underlying these chronic conditions is of relevant importance as it might lead to the identification of novel anti-obesity targets. The purpose of the current study is to investigate differentially expressed proteins between lean and obese subjects through a shot-gun quantitative proteomics approach using peripheral blood mononuclear cells (PBMCs) extracts as well as potential modulation of those proteins by physical exercise. Using this approach, a total of 47 proteins showed at least 1.5 fold change between lean and obese subjects. In obese, the proteomic profiling before and after 3 months of physical exercise showed differential expression of 38 proteins. Thrombospondin 1 (TSP1) was among the proteins that were upregulated in obese subjects and then decreased by physical exercise. Conversely, the histone deacetylase 4 (HDAC4) was downregulated in obese subjects and then induced by physical exercise. The proteomic data was further validated by qRT-PCR, Western blot and immunohistochemistry in both PBMCs and adipose tissue. We also showed that HDAC4 levels correlated positively with maximum oxygen consumption (VO2 Max) but negatively with body mass index, percent body fat, and the inflammatory chemokine RANTES. In functional assays, our data indicated that ectopic expression of HDAC4 significantly impaired TNF-α-dependent activation of NF-κB, establishing thus a link between HDAC4 and regulation of the immune system. Together, the expression pattern of HDAC4 in obese subjects before and after physical exercise, its correlation with various physical, clinical and metabolic parameters along with its inhibitory effect on NF-κB are suggestive of a protective role of HDAC4 against obesity. HDAC4 could therefore represent a potential therapeutic target for the control and management of obesity and presumably insulin resistance.

Background Obesity is characterized by a chronic low-grade inflammation and altered stress responses in key metabolic tissues. Impairment of heat shock response (HSR) has been already linked to diabetes and insulin resistance as reflected by decrease in heat shock proteins (HSPs) expression. However, the status of HSR in non-diabetic human obese has not yet been elucidated. The aim of the current study was to investigate whether obesity triggers a change in the HSR pattern and the impact of physical exercise on this pattern at protein and mRNA levels. Methods Two groups of adult non-diabetic human subjects consisting of lean and obese (n = 47 for each group) were enrolled in this study. The expression pattern of HSP-27, DNAJB3/HSP-40, HSP-60, HSC-70, HSP72, HSP-90 and GRP-94 in the adipose tissue was primarily investigated by immunohistochemistry and then complemented by western blot and qRT-PCR in Peripheral blood mononuclear cells (PBMCs). HSPs expression levels were correlated with various physical, clinical and biochemical parameters. We have also explored the effect of a 3-month moderate physical exercise on the HSPs expression pattern in obese subjects. Results Obese subjects displayed increased expression of HSP-60, HSC-70, HSP-72, HSP-90 and GRP-94 and lower expression of DNAJB3/HSP-40 (P

Obesity is a major risk factor for a myriad of disorders such as insulin resistance and diabetes. The mechanisms underlying these chronic conditions are complex but low grade inflammation and alteration of the endogenous stress defense system are well established. Previous studies indicated that impairment of HSP-25 and HSP-72 was linked to obesity, insulin resistance and diabetes in humans and animals while their induction was associated with improved clinical outcomes. In an attempt to identify additional components of the heat shock response that may be dysregulated by obesity, we used the RT(2)-Profiler PCR heat shock array, complemented with RT-PCR and validated by Western blot and immunohistochemistry. Using adipose tissue biopsies and PBMC of non-diabetic lean and obese subjects, we report the downregulation of DNAJB3 cochaperone mRNA and protein in obese that negatively correlated with percent body fat (P = 0.0001), triglycerides (P = 0.035) and the inflammatory chemokines IP-10 and RANTES (P = 0.036 and P = 0.02, respectively). DNAJB positively correlated with maximum oxygen consumption (P = 0.031). Based on the beneficial effect of physical exercise, we investigated its possible impact on DNAJB3 expression and indeed, we found that exercise restored the expression of DNAJB3 in obese subjects with a concomitant decrease of phosphorylated JNK. Using cell lines, DNAJB3 protein was reduced following treatment with palmitate and tunicamycin which is suggestive of the link between the expression of DNAJB3 and the activation of the endoplasmic reticulum stress. DNAJB3 was also shown to coimmunoprecipiate with JNK and IKKβ stress kinases along with HSP-72 and thus, suggesting its potential role in modulating their activities. Taken together, these data suggest that DNAJB3 can potentially play a protective role against obesity.

Introduction Obesity is characterized by a chronic-low grade inflammation and aberrant regulation of various forms of stress response in key metabolic sites. The white adipose tissue has been identified as the predominant site of obesity-associated inflammatory reactions, which are triggered as a consequence of immune cells infiltration. Physical exercise has been widely recognized for treating obesity and metabolic syndromes. The objectives of this study are: (1) To investigate the release pattern of pro- and anti-inflammatory mediators in obese participants, (2) To evaluate the effect of a defined exercise protocol on their release into the circulation, (3) To correlate their expression with the metabolic and stress markers. Methods A total of 600 healthy individuals divided into 3 groups using the body mass index as a reference (lean, overweight and obese) are being enrolled in a 6-month defined exercise protocol. Blood samples and abdominal subcutaneous adipose biopsies are collected at baseline (t0) and after 3 (t3) and 6 (t6) months of exercise. Plasma cytokine and metabolic markers levels were assessed simultaneously using the xMAP multiplex immunobead assay technology (Bioplex). Markers of the oxidative stress, namely ROS and TBARS were measured on plasma or serum using commercially available kits. Gene expression profile was done by RT-PCR using RT-profiler- array kits consisting of the heat shock protein panel, obesity panel and the oxidative stress panel. Western blotting and immunohistochemistry techniques were used to validate the gene expression data. Statistical analyses were performed using SAS software. Results The analysis carried out on a first set of samples indicated significant release of RANTES in obese individuals compared to lean participants ( P Conclusion Our result demonstrated a differential expression of RANTES chemokine in obese participants in comparison to lean control and highlighted its roles in obesity. Exercise was able to restore the normal expression of RANTES. The existence of a negative correlation between RANTES expression and the metabolic and stress responses is suggestive of a pathological role of RANTES and may be considered a potential therapeutic target.

Association of obesity with down-regulation of heat shock protein 40 expression and evidence that exercise retrieves its normal expression Jehad Abubakr, Mohamed Abu-Farha, Monira Al-Arouj, Fahad Al-Ghimlas, Irina Al-Khairi, Dalal Al-Mudhaf, Engin Baturcam, Abdullah Bennakhi, Preethi Cherian, Maha Hammad, Jeena John, Sina Kavalakatt, Abdelkrim Khadir, Ali Tiss, Samia Warsame, Said Dermime, Mohammed Dehbi