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Disruption of the intracellular lipid balance leading to cholesterol accumulation is one of the features of cells that participate in the development of atherosclerotic lesions. Evidence form our laboratory indicates that anti-inflammatory cyclopentenone prostaglandins (cyPGs) of A- and J-family deviate lipid metabolism from the synthesis of cholesterol and cholesteryl esters to the synthesis of phospholipids in foam-cell macrophages. cyPGs possessing an α,β-unsaturated cyclopentane ring are highly electrophilic substances able to promptly react with reactive cysteines of intracellular molecules through Michael addition. On the other hand, HMG-CoA reductase (HMGCR), the enzyme responsible for the rate-limiting step in cholesterol biosynthesis, presents critically reactive cysteines at the entry of catalytic domain, particularly Cys561, that could be target of cyPG inhibition. In the present study, we showed that cyPGs (but not other non-α,β-unsaturated PGs) physically interact with HMGCR, in a dithiothreitol- and β-mercaptoethanol-sensitive way, and block the activity of the catalytic subunit of the enzyme (IC50 for PGA2 = 0.17 μM). PGA2 inhibits HMGCR activity in cultured rat and human macrophages/macrophage-foam cells and leads to enhanced expression of HMGCR protein, as observed with statins. In cell culture models, PGA2 effectively inhibits the reductase at non-toxic doses (e.g., 1 μM) that block cell proliferation thus suggesting that part of the well-known antiproliferative effect of PGA2 may be due to its ability of blocking HMGCR activity, as cells cannot proliferate without a robust cholesterogenesis. Therefore, besides the powerfully anti-inflammatory and antiproliferative effects, the anticholesterogenic effects of PGA2 should be exploited in atherosclerosis therapeutics.

Menopause is an event resulting from the natural aging of the female organism, in which there is ovarian failure that, consequently, leads to hypoestrogenism. With the gradual decrease of estrogen (E2) levels, women become more susceptible to developing low-grade chronic inflammation. Low levels of E2 reduce the expression of genes that affect the balance between energy expenditure and consumption, in addition to negatively affecting carbohydrate and lipid metabolism. On the other hand, E2 has the ability to induce the expression of the HSP72 protein, one of the members of the 70 kDa family of heat shock proteins, which are anti-inflammatory and cytoprotective, and whose expression is modulated by different types of physiologically stressful situations, including heat stress. Therefore, during perimenopause, various homeostatic functions based on E2-dependent expression of HSP70 may collapse. In this study, we investigated the effects of aging in female mice, focusing on E2-mediated nitric oxide (NO)-induced heat shock response (HSR). We used female mice of the C57BL/6J strain: young (4 months) and aged (16 months) adult animals, being submitted to the following treatments: HS (heat shock treatment for 2 months once a week = 8 sessions with anesthesia) or SHAM (animals kept at room temperature and anesthetized only). We observed that, with regard to the muscular HSP70 content in the gastrocnemius muscle of adult and naturally aged females, there was a 59 % increase in the HS group as compared to the SHAM group in adult females; in the group of aged females, there was a 77 % increase in the HS group compared to the SHAM group (p=0.0341). Still with regard to HSP70 expression, we found a marked difference (p=0.0047) between the different ages of the animals that received the HS, indicating a more accentuated increase in the muscular concentrations of this protein in the aged females. As an effect of HS, we also observed an increase in 17β-Estradiol concentrations compared to the SHAM group (p=0.0467), being 83 % in the HS group (4 months) and 80 % in the HS group (16 months). In total, the results suggest a potential use of HS therapy as an alternative to hormone replacement therapy (HRT), especially its long-term safety has already been questioned. In addition, there are possible protective effects that are being re-established by the HSR pathway, until then suppressed due to the effects of aging/natural menopause of female metabolism, which reduces the metabolic capacity, among other effects, to maintain the hormonal status necessary for cytoprotective levels known.

Eugenol antioxidant and antibacterial properties have suggested its use as a natural preservative for food matrices. Eugenol application is compromised due to its high volatility and sensibility to external agents, such as light, heat, oxygen, and moisture. Thus, microencapsulation is viable to increase the eugenol stability. Results have showed that carrageenan combined with rice protein and bovine albumin allow high-quality eugenol microcapsules. These materials show excellent properties, favoring the microcapsules use in food matrices. This study aimed to optimize microcapsules formulation by spray drying, using a simplex-centroid mixture design. Blends of low-lactose whey protein (WP) and/or rice bran protein (RBP) and/or bovine serum albumin (BSA) with carrageenan were used as wall materials. Blends influenced the eugenol retention, microencapsulation efficiency, and size. Pure WP was not efficient for eugenol encapsulation. The highest eugenol retention values, 89.7% and 86.5% were obtained by combining carrageenan with RBP or BSA. RBP and BSA binary interaction with carrageenan showed the highest encapsulation value (80.5%). Scanning electron microscopy, infrared spectroscopy, and thermogravimetry confirmed eugenol inside the microcapsules.

The major risk factors to fatal outcome in COVID-19 patients, i.e., elderliness and pre-existing metabolic and cardiovascular diseases (CVD), share in common the characteristic of being chronic degenerative diseases of inflammatory nature associated with defective heat shock response (HSR). The molecular components of the HSR, the principal metabolic pathway leading to the physiological resolution of inflammation, is an anti-inflammatory biochemical pathway that involves molecular chaperones of the heat shock protein (HSP) family during homeostasis-threatening stressful situations (e.g., thermal, oxidative and metabolic stresses). The entry of SARS coronaviruses in target cells, on the other hand, aggravates the already-jeopardized HSR of this specific group of patients. In addition, cellular counterattack against virus involves interferon (IFN)-mediated inflammatory responses. Therefore, individuals with impaired HSR cannot resolve virus-induced inflammatory burst physiologically, being susceptible to exacerbated forms of inflammation, which leads to a fatal “cytokine storm”. Interestingly, some species of bats that are natural reservoirs of zoonotic viruses, including SARS-CoV-2, possess an IFN-based antiviral inflammatory response perpetually activated but do not show any sign of disease or cytokine storm. This is possible because bats present a constitutive HSR that is by far (hundreds of times) more intense and rapid than that of human, being associated with a high core temperature. Similarly in humans, fever is a physiological inducer of HSR while antipyretics, which block the initial phase of inflammation, impair the resolution phase of inflammation through the HSR. These findings offer a rationale for the reevaluation of patient care and fever reduction in SARS, including COVID-19.

Microencapsulation of functioning cells for transplantation therapies is particularly promising, but the cells must retain their proper physiology and viability after being encapsulated. K-562 cells are multipotential and exhibit erythroid, megakaryocytic, or granulocytic properties that can be exploited by using an array of physiologically differentiating factors. The potential for cell differentiation makes it attractive the use of K-562 cells as functional model to the assessment of the effects of encapsulation on cell viability and physiology. Thus, alginate and hybrid alginate matrices were produced by extrusion technique for K-562 cell encapsulation. The produced systems were composed of bare alginate (1–3 wt%) and alginate in combination with chitosan or silica. The resulting materials were characterized by dynamic laser scattering, zeta potential measurements, small-angle X-ray scattering, and Fourier transform infrared spectroscopy. To assess viability, the encapsulated cells were subjected to the Trypan blue exclusion technique and NAD(P)H-dependent oxidoreductase (MTT) assays; hemin-induced erythroid differentiation capacity was also evaluated. The encapsulated alginate-based systems were shown to be monomodal and bimodal, depending on the nature of the capsule, with mean sizes in the range between 414 and 4.129 nm. Encapsulated cells exhibited viability ratios compatible with their use for prolonged cell cultures. Erythroid differentiation occurred in the range between 39 and 44%. The present results allow the consideration of the viability of therapeutic cells encapsulated in both bare alginate and in hybrid matrices.

Low estrogen levels may predispose women to increased bodyweight and dyslipidemia. Previous studies from our laboratory suggest an involvement of depressed heat shock response (HSR) in this scenario because estrogen potently stimulates HSR. As heat treatment induces the expression of the anti-inflammatory heat shock proteins of the 70-kDa family (HSP70) and its accompanying HSR, we aimed to investigate whether chronic heat treatment promotes beneficial effects on biometric, lipid profile, oxidative stress, and HSR in ovariectomized rats. Wistar adult female rats (n = 32) were divided into four groups: control (C, n = 7), ovariectomized (OVX, n = 9), heat-treated (HT, n = 9), and heat-treated ovariectomized rats (OVX+HT, n = 7). HT and OVX+HT rats were anesthetized and submitted to heat treatment (once a week for 12 weeks) in a water bath (41 °C) to increase rats’ rectal temperature up to 41 °C for 15 min, while C and OVX animals were submitted to a 36 °C water bath. HT attenuated the weight gain induced by OVX and increased HDL cholesterol and triglyceride serum levels. Also, OVX rats showed increased total cholesterol and LDL cholesterol levels that were not influenced by HT. Interestingly, it was found that an overall trend for HT to decrease tissue catalase and superoxide dismutase antioxidant activities was paralleled by a decrease in malondialdehyde levels (indicative of lower lipoperoxidation), especially in the skeletal muscle. Surprisingly, OVX was not able to depress intracellular HSP70 expression in the skeletal muscle, as expected, and this remained unchanged with HT. However, chronic HT did enhance intracellular HSP70 contents in white adipose tissue of OVX animals. As both glucose and insulin tolerance tests were not affected by OVX, which was not modified by HT, we suppose that estrogen absence alone is not sufficient to determine a state of insulin resistance associated with low intramuscular HSP70 content. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s12192-020-01087-z) contains supplementary material, which is available to authorized users.

Sustainable natural product-based microstructured systems and biopolymers are strong candidates for use in crop protection. Lignin and gelatin microcapsules loaded with orange essential oil were developed with spray-drying in order to enhance its potential. We evaluated the microparticle controlled release mechanisms, biological effects, structural and thermal properties. A quantitative method using headspace-gas chromatography was developed and evaluated for the controlled release of the essential oils. Controlled release studies showed a linear relationship between the biopolymer and essential oil concentrations when retaining volatile compounds. Thermal analyses demonstrated increases in essential oil stability when microencapsulated, especially for lignin as a biopolymer. These results showed that biopolymer type was the main factor influencing quality analysis parameters. Finally, microcapsules loaded with orange essential oil were applied in a bioassay, and showed gains in toxicity against Spodoptera frugiperda compared to non-encapsulated oil.

Introduction and objectives: Obesity represents a major global public health problem. Its etiology is multifactorial and includes poor dietary habits, such as hypercaloric and hyperlipidic diets (HFDs), physical inactivity, and genetic factors. Regular exercise is, per se, a tool for the treatment and prevention of obesity, and recent studies suggest that the beneficial effects of exercise can be potentiated by the fasting state, thus potentially promoting additional effects. Despite the significant number of studies showing results that corroborate such hypothesis, very few have evaluated the effects of fasted-state exercise in overweight/obese populations. Therefore, the aim of this study was to evaluate the subacute effects (12 h after conclusion) of a single moderate-intensity exercise bout, performed in either a fed or an 8 h fasted state, on serum profile, substrate-content and heat shock pathway–related muscle protein immunocontent in obese male rats. Methods: Male Wistar rats received a modified high-fat diet for 12 weeks to induce obesity and insulin resistance. The animals were allocated to four groups: fed rest (FER), fed exercise (FEE), fasted rest (FAR) and fasted exercise (FAE). The exercise protocol was a 30 min session on a treadmill, with an intensity of 60% of VO2max. The duration of the fasting period was 8 h prior to the exercise session. After a 12 h recovery, the animals were killed and metabolic parameters of blood, liver, heart, gastrocnemius and soleus muscles were evaluated, as well as SIRT1 and HSP70 immunocontent in the muscles. Results: HFD induced obesity and insulin resistance. Soleus glycogen concentration decreased in the fasted groups and hepatic glycogen decreased in the fed exercise group. The combination of exercise and fasting promoted a decreased concentration of serum total cholesterol and triglycerides. In the heart, combination fasting plus exercise was able to decrease triglycerides to control levels. In the soleus muscle, both fasting and fasting plus exercise were able to decrease triglyceride concentrations. In addition, heat shock protein 70 and sirtuin 1 immunocontent increased after exercise in the gastrocnemius and soleus muscles. Conclusions: An acute bout of moderate intensity aerobic exercise, when realized in fasting, may induce, in obese rats with metabolic dysfunctions, beneficial adaptations to their health, such as better biochemical and molecular adaptations that last for at least 12 h. Considering the fact that overweight/obese populations present an increased risk of cardiovascular events/diseases, significant reductions in such plasma markers of lipid metabolism are an important achievement for these populations.

Unhealthy lifestyle persistently feeds forward inflammation in metabolic organs thus imposing senescence-associated secretory phenotype (SASP), as observed in obesity and type 2 diabetes. However, SASP blocks physiological resolution of inflammation by suppressing the anti-inflammatory and anti-senescent heat shock (HS) response, i.e., the gene program centered in heat shock factor-1 (HSF1)-dependent expression heat shock proteins (HSPs). As SASP-inducing factors are not removed, leading to the perpetuation of inflammation, we argued that SIRT1-HSF1-HSP axis might also be suppressed in atherosclerosis, which could be reversible by heat treatment (HT), the most powerful HS response trigger. LDLr−/− adult mice were fed on high-fat/high-cholesterol diet from the age of 90 days until the end of study (age of 270 days). After 120 days under atherosclerotic diet, the animals were submitted to either whole-body HT (n = 42; 40 °C) or sham (n = 59; 37 °C) treatment (15 min/session), under anesthesia, once a week, for 8 weeks, being echographically and metabolically monitored. Aortic expressions of SIRT1, HSF1, HSP27, HSP72 and HSP73 were progressively depressed in atherosclerotic animals, as compared to normal (LDLr+/+; n = 25) healthy counterparts, which was paralleled by increased expression of NF-κB-dependent VCAM1 adhesion molecule. Conversely, HT completely reversed suppression of the above HS response proteins, while markedly inhibiting both VCAM1 expression and NF-κB DNA-binding activity. Also, HT dramatically reduced plasma levels of TG, total cholesterol, LDL-cholesterol, oxidative stress, fasting glucose and insulin resistance while rising HDL-cholesterol levels. HT also decreased body weight gain, visceral fat, cellular infiltration and aortic fatty streaks, and heart ventricular congestive hypertrophy, thereby improving aortic blood flow and myocardial performance (Tei) indices. Remarkably, heat-treated mice stopped dying after the third HT session (= 8 human years), suggesting a curative effect. Therefore, evolution of atherosclerosis is associated with suppression of the anti-inflammatory and anti-senescent SIRT1-HSF1-HSP molecular axis, which is refreshed by chronic heat treatment.

Introduction: The 72 kDa heat shock protein, HSP72, located intracellularly provides cochlear cytoprotective and anti-inflammatory roles in the inner ear during stressful noise challenges. The expression of intracellular HSP72 (iHSP72) can be potentiated by alanyl-glutamine dipeptide supplementation. Conversely, these proteins act as pro-inflammatory signals in the extracellular milieu (eHSP72). Objective: We explore whether noise-induced hearing loss promotes both intracellular and extracellular HSP72 heat shock response alterations, and if alanyl-glutamine dipeptide supplementation could modify heat shock response and prevent hearing loss. Methods: Female 90 day-old Wistar rats (n = 32) were randomly divided into four groups: control, noise-induced hearing loss, treated with alanyl-glutamine dipeptide and noise-induced hearing loss plus alanyl-glutamine dipeptide. Auditory brainstem responses were evaluated before noise exposure (124 dB SPL for 2 h) and 14 days after. Cochlea, nuclear cochlear complex and plasma samples were collected for the measurement of intracellular HSP72 and extracellular HSP72 by a high-sensitivity ELISA kit. Results: We found an increase in both iHSP72 and eHSP72 levels in the noise-induced hearing loss group, which was alleviated by alanyl-glutamine dipeptide treatment. Furthermore, H-index of HSP72 (plasma/cochlea eHSP72/iHSP72 ratio) was increased in the noise-induced hearing loss group, but prevented by alanyl-glutamine dipeptide treatment, although alanyl-glutamine dipeptide had no effect on auditory threshold. Conclusions: Our data indicates that cochlear damage induced by noise exposure is accompanied by local and systemic heat shock response markers. Also, alanyl-glutamine reduced stress markers even though it had no effect on noise-induced hearing loss. Finally, plasma levels of 72 kDa heat shock proteins can be used as a biomarker of auditory stress after noise exposure. Resumo: Introdução: A proteína de choque térmico de 72 kDa, HSP72 localizada intracelularmente (iHSP72) possui papéis citoprotetores e anti-inflamatórios cocleares na orelha interna durante situações de ruído estressantes. A expressão dessa proteina pode ser potencializada pela suplementação com dipeptídeo de alanil-glutamina. Por outro lado, essas proteínas atuam como sinais pró-inflamatórios no meio extracelular (eHSP72). Objetivo: Investigar se a perda auditiva induzida por ruído promove alterações tanto das proteínas HSP72 intracelulares quanto extracelulares na resposta de choque térmico e se a suplementação com alanil-glutamina pode modificar a resposta de choque térmico e evitar a perda auditiva. Método: Ratos Wistar fêmeos, com 90 dias de idade (n = 32) foram divididas aleatoriamente em quatro grupos: controle, perda auditiva induzida por ruído, tratados com alanil-glutamina e perda auditiva induzida por ruído mais alanil-glutamina. Os potenciais evocados auditivos do tronco encefálico foram avaliados antes da exposição ao ruído (124 dB NPS por 2 h) e 14 dias após. A cóclea, o complexo nuclear coclear e amostras de plasma foram coletadas para mensuração de HSP72 intra e extracelular com um kit Elisa de alta sensibilidade. Resultados: Houve um aumento nos níveis de HSP72 intra e extracelular no grupo perda auditiva induzida por ruído, que foi minimizado pelo tratamento com alanil-glutamina. Além disso, o índice H das HSP72 (razão eHSP72 no plasmacom alanil-glutamina, embora/cóclea) aumentou no grupo perda auditiva induzida por ruído, mas foi limitado pelo tratamento com alanil-glutamina, embora o alanil-glutamina não tenha efeito no limiar auditivo. Conclusões: Nossos dados indicam que o dano coclear induzido pela exposição ao ruído é acompanhado por marcadores da resposta de choque térmico locais e sistêmicos. Além disso, alanil-glutamina reduziu os marcadores de estresse, mesmo não tendo efeito sobre a perda auditiva induzida por ruído. Finalmente, os níveis plasmáticos de proteínas de choque térmico de 72 kDa podem ser usados como biomarcador do estresse auditivo após a exposição ao ruído.

Recent evidence suggests that the anti-inflammatory heat shock response (HSR) is reduced in aging and diabetes. In this study we compared HSR between healthy middle-aged adults, healthy elderly and type 2 diabetic (T2DM) elderly, and tested whether resistance training (RT) could improve the HSR in T2DM group. Thirty sedentary participants volunteered for this study. HSR (assessed as the capacity to export HSP72 during heat stress) was measured in the blood and compared between the groups. HSR was similar between healthy middle-aged and healthy elderly volunteers, but diminished in elderly T2DM (p 0.001). Hence, T2DM subjects (n = 12) were submitted to a 12-week RT program, because exercise is a physiological HSR inducer. HSR, cytokines, metabolic parameters and visceral adipose tissue (VAT) were measured before and after the RT. Remarkably, VAT was negatively correlated with HSR (r = - 0.49, p 0.01) while RT improved the HSR and reduced inflammation [TNF-α: from 51.5 ± 9 to 40.7 ± 4 pg/mL and TNF-α/IL-10 ratio: from 1.55 ± 0.3 to 1.16 ± 0.2 (p 0.001)], without affecting other parameters. All together, these findings confirm the hypothesis that the anti-inflammatory HSR is depressed in elderly diabetic people, but can be partially restored by RT.

Exercise training has been shown to be an effective strategy to balance oxidative stress status; however, this is underexplored in people living with HIV/AIDS (PLWHA).To evaluate the effects of exercise training on oxidative stress in PLWHA receiving antiretroviral therapy.Patients performed 24 sessions (3 times per week, 8 weeks) of either aerobic (AT), resistance (RT), or concurrent training (CT). Glutathione disulphide to glutathione ratio (GSSG/GSH) in circulating erythrocytes and thiobarbituric acid-reactive substances (TBARS) in plasma samples were assessed as oxidative stress markers. Eight PLWAH completed the training protocol (AT =3, RT =3, CT =2). The GSSG/GSH and TBARS values were logarithmically transformed to approximate a normal distribution. A paired t-test was used to determine the differences between baseline and post-training values.Data-pooled analysis showed a decrease in GSSG/GSH and TBARS after the training period: log GSSG/GSH= -1.26 ± 0.57 versus -1.54 ± 0.65, p = .01 and log TBARS =0.73 ± 0.35 versus 0.43 ± 0.21, p = .01. This was paralleled by a rise in peak oxygen uptake (VO

Heat shock proteins of the 70-kDa (HSP70) family are cytoprotective molecular chaperones that are present in neuronal cells and can be induced by a variety of homeostatically stressful situations (not only proteostatic insults), but also by synaptic activity, including learning tasks. Physiological stimuli that induce long-term memory formation are also capable of stimulating the synthesis of HSP70 through the activation of heat shock transcription factor-1 (HSF1). In this study, we investigated the influence of HSP70 on fear memory consolidation and MAPK activity. Male rats were trained in contextual fear conditioning task and HSP70 content was analyzed by western blot in the hippocampus at different time points. We observed rapid and transient elevations in HSP70 60 min following training. Double immunofluorescence with GFAP and HSP72 revealed that astrocytes were not the site for HSP72 induction by CFC training. HSP72 distribution markedly surrounded synapses between Shaffer collateral and CA1 pyramidal cells. Infusion of recombinant HSP70 (hspa1a) into the dorsal hippocampus immediately after training facilitated memory consolidation and enhanced ERK activity while decreasing the activated forms of JNK and p38 in the hippocampus. Blocking endogenous extracellular HSP70 through the administration of specific antibody did not produce any further effect on memory consolidation when applied immediately after training, suggesting that it is indeed acting intracellularly. Induction of HSP70 after fear conditioning is fast and can act as a signaling molecule, modulating MAPK downstream signaling during memory consolidation in the hippocampus, which is crucial for fear memory formation.

Background Although some unequivocal underlying mechanisms of menopausal hot flushes have been demonstrated in animal models, the paucity of similar approaches in humans impedes further mechanistic outcomes. Human studies might show some as yet unexpected physiological mechanisms of metabolic adaptation that permeate the phase of decreased oestrogen levels in both symptomatic and asymptomatic women. This is particularly relevant because both the severity and time span of hot flushes are associated with increased risk of chronic inflammatory disease. On the other hand, oestrogen induces the expression of heat shock proteins of the 70 kDa family (HSP70), which are anti-inflammatory and cytoprotective protein chaperones, whose expression is modulated by different types of physiologically stressful situations, including heat stress and exercise. Therefore, lower HSP70 expression secondary to oestrogen deficiency increases cardiovascular risk and predisposes the patient to senescence-associated secretory phenotype (SASP) that culminates in chronic inflammatory diseases, such as obesities, type 2 diabetes, neuromuscular and neurodegenerative diseases. Objective and rationale This review focuses on HSP70 and its accompanying heat shock response (HSR), which is an anti-inflammatory and antisenescent pathway whose intracellular triggering is also oestrogen-dependent via nitric oxide (NO) production. The main goal of the manuscript was to show that the vasomotor symptoms that accompany hot flushes may be a disguised clue for important neuroendocrine alterations linking oestrogen deficiency to the anti-inflammatory HSR. Search methods Results from our own group and recent evidence on hypothalamic control of central temperature guided a search on PubMed and Google Scholar websites. Outcomes Oestrogen elicits rapid production of the vasodilatory gas NO, a powerful activator of HSP70 expression. Whence, part of the protective effects of oestrogen over cardiovascular and neuroendocrine systems is tied to its capacity of inducing the NO-elicited HSR. The hypothalamic areas involved in thermoregulation (infundibular nucleus in humans and arcuate nucleus in other mammals) and whose neurons are known to have their function altered after long-term oestrogen ablation, particularly kisspeptin-neurokinin B-dynorphin neurons, (KNDy) are the same that drive neuroprotective expression of HSP70 and, in many cases, this response is via NO even in the absence of oestrogen. From thence, it is not illogical that hot flushes might be related to an evolutionary adaptation to re-equip the NO-HSP70 axis during the downfall of circulating oestrogen. Wider implications Understanding of HSR could shed light on yet uncovered mechanisms of menopause-associated diseases as well as on possible manipulation of HSR in menopausal women through physiological, pharmacological, nutraceutical and prebiotic interventions. Moreover, decreased HSR indices (that can be clinically determined with ease) in perimenopause could be of prognostic value in predicting the moment and appropriateness of starting a HRT.

Chronic obesity imposes an organismal state of low-grade inflammation because the physiological resolution of inflammation is progressively repressed giving rise to cellular senescence and its accompanying S enescence- A ssociated S ecretory P henotype (SASP), which avoids apoptosis but perpetuates the relay of inflammatory signals from adipose tissue toward the rest of the body. Conversely, resolution of inflammation depends on the integrity of heat shock response (HSR) pathway that leads to the expression of cytoprotective and anti-inflammatory protein chaperones of the 70 kDa family (HSP70). However, chronic exposure to the aforementioned injuring factors leads to SASP, which, in turn, suppresses the HSR. A main metabolic tissue severely jeopardized by obesity-related dysfunctions is the endocrine pancreas, particularly β-cells of the islets of Langerhans. Because exercise is a powerful inducer of HSR and predicted to alleviate negative health outcomes of obesity, we sought whether obesity influence HSP70 expression in pancreatic islets and other metabolic tissues (adipose tissue and skeletal muscle) of adult B6.129SF2/J mice fed on a high-fat diet (HFD) for 13 weeks since the weaning and whether acute exercise as well as moderate-intensity exercise training (8 weeks) could interfere with this scenario. We showed that acute exercise of moderate intensity protects pancreatic islets against cytokine-induced cell death. In addition, acute exercise challenge time-dependently increased islet HSP70 that peaked at 12 h post-exercise in both trained and untrained mice fed on a control diet, suggesting an adequate HSR to exercise training. Unexpectedly, however, neither exercise training nor acute exercise challenges were able to increase islet HSP70 contents in trained mice submitted to HFD, but only in untrained HFD animals. In parallel, HFD disrupted glycemic status which is accompanied by loss of muscular mass resembling sarcopenic obesity that could not be rescued by exercise training. These results suggest that exercise influences HSR in pancreatic islets but obesity undermines islet, muscle and adipose tissue HSR, which is associated with metabolic abnormalities observed in such tissues.

Oxidative stress and chronic inflammation are known to be associated with the development of metabolic diseases, including diabetes. Oxidative stress, an imbalance between oxidative and antioxidative systems of cells and tissues, is a result of over production of oxidative-free radicals and associated reactive oxygen species (ROS). One outcome of excessive levels of ROS is the modification of the structure and function of cellular proteins and lipids, leading to cellular dysfunction including impaired energy metabolism, altered cell signalling and cell cycle control, impaired cell transport mechanisms and overall dysfunctional biological activity, immune activation and inflammation. Nutritional stress, such as that caused by excess high-fat and/or carbohydrate diets, promotes oxidative stress as evident by increased lipid peroxidation products, protein carbonylation and decreased antioxidant status. In obesity, chronic oxidative stress and associated inflammation are the underlying factors that lead to the development of pathologies such as insulin resistance, dysregulated pathways of metabolism, diabetes and cardiovascular disease through impaired signalling and metabolism resulting in dysfunction to insulin secretion, insulin action and immune responses. However, exercise may counter excessive levels of oxidative stress and thus improve metabolic and inflammatory outcomes. In the present article, we review the cellular and molecular origins and significance of ROS production, the molecular targets and responses describing how oxidative stress affects cell function including mechanisms of insulin secretion and action, from the point of view of possible application of novel diabetic therapies based on redox regulation

Moderate exercise positively impacts innate immune functions, bringing about a better resistance against infections and general immunosurveillance. Exercise of high workloads (i.e., high intensity and/or duration) such as elite marathon, on the other hand, may have detrimental effects over immune function, but neither how long nor how intense should be the exercise sessions to be deleterious is known, this being a matter of intense dispute. Exercise is, at the same time, one of the most powerful inducers of the 70 kDa family of heat shock proteins (HSPAs, formerly known as HSP70s), which are protein chaperones characterized by a marked anti-inflammatory potency, when located intracellularly (iHSPA), but may act as pro-inflammatory cytokines if in the extracellular space (eHSPA). The above observations led us to suppose that short-term exercise could impose long-lasting effects on macrophage function that should be related to the eHSPA-to-iHSPA ratio, viz. H-index. Sedentary adult male Wistar rats were then submitted to 20 min swimming sessions with an overload (as a percentage of body weight attached to the tail base) of either 2, 4, 6, or 8 %. Control animals were maintained at rest in shallow water. Monocyte/macrophage functions (phagocytic capacity, nitric oxide [NO], and hydrogen peroxide [H2O2]) were assessed just after and 12 h after exercise and compared with HSPA status and oxidative stress markers. The results showed that exercise increased phagocytosis and H2O2 immediately after the bouts in a workload-dependent way. This was accompanied by increased H-index but no alteration in the redox status. Enhanced phagocytic capacity persisted for up to 12 h, when a marked rise in NO production was also observed, but H-index resumes its control values, suggesting that immune alertness returned to basal levels. Of note was the detection of the cognate form of eHSPA (encoded by hspa8 gene and formerly known as HSP73) in the rat sera. In total, acute exercise may evoke 12 h long workload-dependent effects associated with HSPA status.

Aims To investigate the effects of high-intensity interval training (HIIT) and/or strength training (ST) on inflammatory, oxidative stress (OS) and glycemic parameters in type 1 diabetes (T1DM) patients. Methods After a 4-week control period, volunteers were randomly assigned to 10-week HIIT, ST or ST + HIIT protocol, performed 3×/week. Blood biochemistry, anthropometric, strength and cardiopulmonary fitness variables were assessed. Outcomes were analyzed via generalized estimating equations (GEE), with Bonferroni post hoc analysis. Results ST, HIIT and ST + HIIT improved glycemic (HbA1c and fasting glucose) and antioxidant parameters (total antioxidant capacity, catalase and superoxide dismutase activities), but not plasma inflammatory (C-reactive protein, TNF-α and IL-10) or OS markers (thiobarbituric acid-reactive substances, 8-hydroxy-2-deoxyguanosine and oxLDL) levels. Noteworthy, interventions reduced soluble receptors for advanced glycation end products levels. However, intracellular heat shock protein 70 content increased only after HIIT. While daily insulin dosage decreased only in the ST + HIIT group, all training models induced anthropometric and functional benefits. Conclusions Similar benefits afforded by ST, HIIT or ST + HIIT in T1DM people are associated with enhanced antioxidant systems and glucose-related parameter, even in a few weeks. From a practical clinical perspective, the performance of ST + HIIT may be advised for additional benefits regarding insulin dosage reduction.

Background The relationship between diabetes and oxidative stress has been previously reported. Exercise represents a useful non-pharmacological strategy for the treatment in type 2 diabetic (T2DM) patients, but high intensity exercise can induce a transient inflammatory state and increase oxidative stress. Nutritional strategies that may contribute to the reduction of oxidative stress induced by acute exercise are necessary. The aim of this study was to examine if n-3 PUFA supplementation intervention can attenuate the inflammatory response and oxidative stress associated with high intensity exercise in this population. As a primary outcome, lipoperoxidation measurements (TBARS and F2-isoprostanes) were selected. Methods Thirty T2DM patients, without chronic complications, were randomly allocated into two groups: placebo (gelatin capsules) or n-3 PUFA (capsules containing 180 mg of eicosapentaenoic acid and 120 mg of docosahexaenoic acid). Blood samples were collected fasting before and after 8 weeks supplementation. In the beginning and at the end of protocol, an acute exercise was performed (treadmill), and new blood samples were collected before and immediately after the exercise for measurements of oxidative stress and high-sensitivity C-reactive protein (hs-CRP). Results After the supplementation period, a decrease in triglycerides levels was observed only in n-3 PUFA supplementation group (mean difference and 95% CI of 0.002 (0.000–0.004), p = 0.005). Supplementation also significantly reduced TRAP levels after exercise (mean difference and 95% CI to 9641 (− 20,068–39,351) for − 33,884 (− 56,976 - -10,793), p = 0.004, Cohen’s d effect size = 1.12), but no significant difference was observed in n-3 PUFA supplementation group in lipoperoxidation parameters as TBARS (mean difference and 95% CI to − 3.8 (− 10–2.4) for − 2.9 (− 1.6–7.4) or F2-isoprostanes (mean difference and 95% CI -0.05 (− 0.19–0.10) for − 0.02 (− 0.19–0.16), p > 0.05 for both. Conclusion PUFA n-3 supplementation reduced triglycerides as well as TRAP levels after exercise, without a significant effect on inflammatory and oxidative stress markers. This study is registered at ClinicalTrials.gov with the registration number of NCT03182712.

Aim. The purpose of this study was to determine the response of circulating markers of lipid and protein oxidation following an incremental test to exhaustion before and after 4 weeks of high-intensity interval training performed in the heat. Methods. To address this question, 16 physically active men (age = 23 ± 2 years; body mass = 73 ± 12 kg; height = 173 ± 6 cm; % body fat = 12.5 ± 6 %; body mass index = 24 ± 4 kg/m2) were allocated into 2 groups: control group (n = 8) performing high-intensity interval training at 22°C, 55% relative humidity and heat group (n = 8) training under 35°C, 55% relative humidity. Both groups performed high-intensity interval training 3 times per week for 4 consecutive weeks, accumulating a total of 12 training sessions. Before and after the completion of 4 weeks of high-intensity interval training, participants performed an incremental cycling test until exhaustion under temperate environment (22°C, 55% relative humidity) where blood samples were collected after the test for determination of exercise-induced changes in oxidative damage biomarkers (thiobarbituric acid reactive species and protein carbonyls). Results. When high-intensity interval training was performed under control conditions, there was an increase in protein carbonyls (p < 0.05) following the incremental test to exhaustion with no changes in thiobarbituric acid reactive species. Conversely, high-intensity interval training performed in high environmental temperature enhanced the incremental exercise-induced increases in thiobarbituric acid reactive species (p < 0.05) with no changes in protein carbonyls. Conclusion. In conclusion, 4 weeks of high-intensity interval training performed in the heat enhances exercise-induced lipid peroxidation, but prevents protein oxidation following a maximal incremental exercise in healthy active men.

Glucagon-like peptide-1 (GLP-1) promotes insulin secretion from pancreatic β-cells in a glucose dependent manner. Several pathways mediate this action by rapid, kinase phosphorylation-dependent, but gene expression-independent mechanisms. Since GLP-1-induced insulin secretion requires glucose metabolism, we aimed to address the hypothesis that GLP-1 receptor (GLP-1R) signalling can modulate glucose uptake and utilization in β-cells. We have assessed various metabolic parameters after short and long exposure of clonal BRIN-BD11 β-cells and rodent islets to the GLP-1R agonist Exendin-4 (50 nM). Here we report for the first time that prolonged stimulation of the GLP-1R for 18 hours promotes metabolic reprogramming of β-cells. This is evidenced by up-regulation of glycolytic enzyme expression, increased rates of glucose uptake and consumption, as well as augmented ATP content, insulin secretion and glycolytic flux after removal of Exendin-4. In our model, depletion of Hypoxia-Inducible Factor 1 alpha (HIF-1α) impaired the effects of Exendin-4 on glucose metabolism, while pharmacological inhibition of Phosphoinositide 3-kinase (PI3K) or mTOR completely abolished such effects. Considering the central role of glucose catabolism for stimulus-secretion coupling in β-cells, our findings suggest that chronic GLP-1 actions on insulin secretion include elevated β-cell glucose metabolism. Moreover, our data reveal novel aspects of GLP-1 stimulated insulin secretion involving de novo gene expression.

Exercise stimulates immune responses, but the appropriate “doses” for such achievements are unsettled. Conversely, in metabolic tissues, exercise improves the heat shock (HS) response, a universal cytoprotective response to proteostasis challenges that are centred on the expression of the 70-kDa family of intracellular heat shock proteins (iHSP70), which are anti-inflammatory. Concurrently, exercise triggers the export of HSP70 towards the extracellular milieu (eHSP70), where they work as pro-inflammatory cytokines. As the HS response is severely compromised in chronic degenerative diseases of inflammatory nature, we wondered whether acute exercise bouts of different intensities could alter the HS response of lymphocytes from secondary lymphoid organs and whether this would be related to immunoinflammatory responses. Adult male Wistar rats swam for 20 min at low, moderate, high or strenuous intensities as per an overload in tail base. Controls remained at rest under the same conditions. Afterwards, mesenteric lymph node lymphocytes were assessed for the potency of the HS response (42 °C for 2 h), NF-κB binding activity, mitogen-stimulated proliferation and cytokine production. Exercise stimulated cell proliferation in an “inverted-U” fashion peaking at moderate load, which was paralleled by suppression of NF-κB activation and nuclear location, and followed by enhanced HS response in relation to non-exercised animals. Comparative levels of eHSP70 to iHSP70 (H-index) matched IL-2/IL-10 ratios. We conclude that exercise, in a workload-dependent way, stimulates immunoinflammatory performance of lymphocytes of tissues far from the circulation and this is associated with H-index of stress response, which is useful to assess training status and immunosurveillance balance.

Objectives To evaluate whether reduced activity of the anti-inflammatory HSP70 pathway correlates with nonalcoholic fatty liver disease (NAFLD) progression and with markers of oxidative stress because obesity activates inflammatory JNKs, whereas HSP70 exerts the opposite effect. Methods Adult obese patients (N = 95) undergoing bariatric surgery were divided into steatosis (ST), steatohepatitis (SH), and fibrosis (SH+F) groups. The levels of HSP70, its major transcription factor, HSF1, and JNKs were assessed by immunoblotting hepatic and visceral adipose tissue; data were confirmed by immunohistochemistry. Plasma biochemistry (lipids, HbA1c, HOMA, hepatic enzymes, and redox markers) was also evaluated. Results In both liver and adipose tissue, decreased HSP70 levels, paralleled by similar reductions in HSF1 and reduced plasma antioxidant enzyme activities, correlated with insulin resistance and with NAFLD progression (expression levels were as follows: ST > SH > SH + F). The immunohistochemistry results suggested Kupffer cells as a site of HSP70 inhibition. Conversely, JNK1 content and phosphorylation increased. Conclusions Decreased HSF1 levels in the liver and fat of obese patients correlated with impairment of HSP70 in an NAFLD stage-dependent manner. This impairment may affect HSP70-dependent anti-inflammation, with consequent oxidative stress and insulin resistance in advanced stages of NAFLD. Possible causal effects of fat cell senescence are discussed.

Purpose of review Obesity is a chronic inflammatory disease in which the physiological resolution of inflammation is attenuated, leading to low-grade inflammation throughout the body. However, the heat shock response, which is a key component of the physiological response to resolve inflammation, is seriously hampered in adipose tissue and other metabolic organs (e.g. skeletal muscle, liver, pancreatic β-cells) in metabolic diseases. In this review, we hypothesize that adipocyte metabolic stress triggers the onset of fat cell senescence, and companion senescence-associated secretory phenotype (SASP), and that such a scenario is responsible for attenuating the resolution of inflammation. Recent findings We shall discuss the role of the heat shock response in the context of the resolution of inflammation and the relevance of heat shock response blockade in chronic inflammatory diseases. Sirtuin-1 is responsible for the induction of heat shock transcription factor-1 mRNA expression and for the stabilization of heat shock transcription factor-1 in a high-profile activity state. However, adipose tissue-emanated SASP depress sirtuin-1 expression, leading adipocytes to a perpetual state of unresolved inflammation, due to a dampening of the heat shock response. Summary The advance of inflammasome-mediated SASP from adipose to other tissues promotes cellular senescence in many other cells of the organism, aggravating obesity-dependent chronic inflammation. Inducers of heat shock response (e.g. heat shock itself, physical exercise and calorie restriction) may efficiently interrupt this vicious cycle and are envisaged as the best and also the most economical treatment for obesity-related chronic diseases.

Expression of intracellular HSP70 is associated with cytoprotective effects against a wide range of stressful stimuli, such as inflammation, oxidative stress, hypoxia, endotoxins, infections, and fever. This cytoprotective effect is mainly attributed to their ability to stabilize protein structures through chaperone-like reversible interactions. HSP70 was recently detected in the extracellular medium, and its presence in serum is commonly associated with pathological situations, where it exerts modulatory effects on cells of the immune system. Previously, we have described the relationship between serum HSP70 levels, oxidant status, and clinical outcome of septic patients; the group of patients with higher prooxidant status and higher serum HSP70 had also higher mortality. To investigate the possible association between oxidized HSP70 and cytoprotection or cell death, we incubated RAW 264.7 macrophages with oxidized HSP70 and evaluated nitrite production, cell proliferation, cell viability, TNF-α release, and phagocytic activity. We also evaluated structural modifications caused by oxidation in purified HSP70. Oxidation of HSP70 altered its protein structure; besides, the modulatory effect of oxidized HSP70 on RAW264.7 cells was different from that of native HSP70. Macrophages treated with oxidized HSP70 presented lower proliferation and viability, lower phagocytic activity, and lower TNF-α release. These results indicate that oxidation of extracellular HSP70 modified its signaling properties, causing alterations on its modulatory effects on macrophage function and viability.

This study aimed to describe and compare ballet dancers' cardiorespiratory responses, muscle damage and oxidative stress levels during a ballet class (practice of isolated ballet exercises performed with barre/hand-rail support and across-the-floor movements to improve technical skills) and rehearsal (practice of ballet choreography involving technical-artistic skills to improve dancers' performance for shows). The 12 advanced female ballet dancers undertook three exercise sessions: maximum effort test, class and rehearsal. Heart rate (HR) and oxygen consumption (VO2) were continuously measured. Lactate was determined before 15 min and after class and rehearsal. Blood was sampled pre, post and 48 h after class and rehearsal for creatine kinase (CK), lipid peroxides (LPO) and glutathione analysis (GSSG/GSH). Class was of lower intensity than rehearsal as shown by VO2, HR and lactate values: VO2 (mL.kg(-1).min(-1)): 14.5±2.1 vs. 19.1±1.7 (p < 0.001); HR (bpm.min(-1)): 145.7±17.9 vs. 174.5±13.8 (p < 0.001); lactate (mmol.L(-1)): 4.2±1.1 vs. 5.5±2.7 (p = 0.049). CK (IU) increased following class and rehearsal, remaining high 48 h after: class (pre = 109.3±48.5; post = 144±60; 48 h = 117.2±64.6); rehearsal (pre = 78.6±52.1; post = 122±70.7; 48 h = 104.9±89.5). LPO (µM) increased from pre-class (1.27±0.19) to post-class (1.41±0.19) and went down after 48 h (1.20±0.22). No LPO time-course changes followed the rehearsal. GSSG/GSH decreased 48 h after class and rehearsal. Greater increases in LPO post-class suggest it promotes CK release by an oxidative membrane-damage mechanism. Physiological increases of LPO and CK in class indicate it prepares the dancers for exercise-induced oxidative stress and muscle damage during rehearsals. Ballet dancers' muscle damage and oxidative stress responses seem not to be dependent on exercise intensity based on VO2 responses.

Aging is an intricate process modulated by different molecular and cellular events, such as genome instability, epigenetic and transcriptional changes, molecular damage, cell death and senescence, inflammation, and metabolic dysfunction. Particularly, protein quality control (chaperone systems) tends to be negatively affected by aging, thus leading to cellular senescence in metabolic tissues and, as a consequence, to the increasing dissemination of inflammation throughout the body. The heat shock (HS) response and its associated expression of the 70 kDa family of heat shock proteins (HSP70), which are anti-inflammatory molecular chaperones, are found to be markedly decreased during muscle inactivity and aging, while evidence supports the loss of HSP70 as a key mechanism which may drive muscle atrophy, contractile dysfunction, and reduced regenerative capacity. In addition, abnormal stress response is linked with higher incidence of neurodegenerative diseases as well as low-grade inflammatory diseases that are associated with physical inactivity and obesity. Therefore, strategies to increase or, at least, to maintain the levels of HSP70, and its accompanying HS response to stress, are key to reduce biological cell dysfunctions that occur in aging. In this sense, physical exercise is of note as it is the most powerful inducer of the HS response, comparable only to heat stress and fever-like conditions. On the other hand, the amino acid l-glutamine, whose production within the skeletal muscle and liberation into the blood stream is dependent on muscle activity, is a potentializer of HSP70 expression and HS response, particularly via its entering in hexosamine biosynthetic pathway (HBP). Herein, we discuss the collaborative role of glutamine (and its donors/precursors) and physical exercise (mostly responsible for glutamine release into the circulation) as potential tools to increase HSP70 expression and the HS response in the elderly.

Exposure to fine particulate matter (PM2.5) air pollution is a risk factor for type 2 diabetes (T2DM). We argue whether the potentiating effect of PM2.5 over the development of T2DM in high-fat diet (HFD)-fed mice would be related to modification in cell stress response, particularly in antioxidant defenses and 70-kDa heat shock proteins (HSP70) status. Male mice were fed standard chow or HFD for 12 weeks and then randomly exposed to daily nasotropic instillation of PM2.5 for additional 12 weeks under the same diet schedule, divided into four groups (n = 14–15 each): Control, PM2.5, HFD, and HFD + PM2.5 were evaluated biometric and metabolic profiles of mice, and cellular stress response (antioxidant defense and HSP70 status) of metabolic tissues. Extracellular to intracellular HSP70 ratio ([eHSP72]/[iHSP70]), viz. H-index, was then calculated. HFD + PM2.5 mice presented a positive correlation between adiposity, increased body weight and glucose intolerance, and increased glucose and triacylglycerol plasma levels. Pancreas exhibited lower iHSP70 expression, accompanied by 3.7-fold increase in the plasma to pancreas [eHSP72]/[iHSP70] ratio. Exposure to PM2.5 markedly potentiated metabolic dysfunction in HFD-treated mice and promoted relevant alteration in cell stress response assessed by [eHSP72]/[iHSP70], a relevant biomarker of chronic low-grade inflammatory state and T2DM risk.

The importance of metabolic pathways for life and the nature of participating reactions have challenged physiologists and biochemists for over a hundred years. Eric Arthur Newsholme contributed many original hypotheses and concepts to the field of metabolic regulation, demonstrating that metabolic pathways have a fundamental thermodynamic structure and that near identical regulatory mechanisms exist in multiple species across the animal kingdom. His work at Oxford University from the 1970s to 1990s was groundbreaking and led to better understanding of development and demise across the lifespan as well as the basis of metabolic disruption responsible for the development of obesity, diabetes and many other conditions. In the present review we describe some of the original work of Eric Newsholme, its relevance to metabolic homoeostasis and disease and application to present state-of-the-art studies, which generate substantial amounts of data that are extremely difficult to interpret without a fundamental understanding of regulatory principles. Eric's work is a classical example of how one can unravel very complex problems by considering regulation from a cell, tissue and whole body perspective, thus bringing together metabolic biochemistry, physiology and pathophysiology, opening new avenues that now drive discovery decades thereafter. * ACC, : acetyl-CoA carboxylase; AMPK, : AMP-activated protein kinase; CaMKK, : calmodulin-dependent protein kinase kinase; GLUT, : glucose transporter; GDH, : glutamate dehydrogenase; GLS, : glutaminase; GS, : glutamine synthetase; HIF, : hypoxia-inducible factor; HK, : hexokinase; LKB1, : liver kinase B1; mTOR, : mammalian target of rapamycin; mTORC1, : mTOR complex 1; PDHK, : pyruvate dehydrogenase kinase; PFK, : phosphofructokinase; SIRT4, : sirtuin 4; SLC, : solute carrier; TAK, : transforming growth factor-beta-activating kinase; TCA, : tricarboxylic acid

Interleukin-6 (IL6) has recently been reported to promote insulin secretion in a glucagon-like peptide-1-dependent manner. Herein, the direct effects of IL6 (at various concentrations from 0 to 1000 pg/ml) on pancreatic β-cell metabolism, AMP-activated protein kinase (AMPK) signaling, insulin secretion, nitrite release, and redox status in a rat clonal β-cell line and mouse islets are reported. Chronic insulin secretion (in μg/mg protein per 24 h) was increased from 128.7±7.3 (no IL6) to 178.4±7.7 (at 100 pg/ml IL6) in clonal β-cells and increased significantly in islets incubated in the presence of 5.5 mM glucose for 2 h, from 0.148 to 0.167±0.003 ng/islet. Pretreatment with IL6 also induced a twofold increase in basal and nutrient-stimulated insulin secretion in subsequent 20 min static incubations. IL6 enhanced both glutathione (GSH) and glutathione disulphide (GSSG) by nearly 20% without changing intracellular redox status (GSSG/GSH). IL6 dramatically increased iNOS expression (byca. 100-fold) with an accompanying tenfold rise in nitrite release in clonal β-cells. Phosphorylated AMPK levels were elevated approximately twofold in clonal β-cells and mouse islet cells. Calmodulin-dependent protein kinase kinase levels (CaMKK), an upstream kinase activator of AMPK, were also increased by 50% after IL6 exposure (in β-cells and islets). Our data have demonstrated that IL6 can stimulate β-cell-dependent insulin secretion via direct cell-based mechanisms. AMPK, CaMKK (an upstream kinase activator of AMPK), and the synthesis of nitric oxide appear to alter cell metabolism to benefit insulin secretion. In summary, IL6 exerts positive effects on β-cell signaling, metabolism, antioxidant status, and insulin secretion.

In this work, our aim was to determine whetherl-arginine (a known insulinotropic amino acid) can promote a shift of β-cell intermediary metabolism favoring glutathione (GSH) and glutathione disulfide (GSSG) antioxidant responses, stimulus–secretion coupling and functional integrity. Clonal BRIN-BD11 β-cells and mouse islets were cultured for 24 h at variousl-arginine concentrations (0–1.15 mmol/l) in the absence or presence of a proinflammatory cytokine cocktail (interleukin 1β, tumour necrosis factor α and interferon γ). Cells were assessed for viability, insulin secretion, GSH, GSSG, glutamate, nitric oxide (NO), superoxide, urea, lactate and for the consumption of glucose and glutamine. Protein levels of NO synthase-2, AMP-activated protein kinase (AMPK) and the heat shock protein 72 (HSP72) were also evaluated. We found thatl-arginine at 1.15 mmol/l attenuated the loss of β-cell viability observed in the presence of proinflammatory cytokines.l-Arginine increased total cellular GSH and glutamate levels but reduced the GSSG/GSH ratio and glutamate release. The amino acid stimulated glucose consumption in the presence of cytokines while also stimulating AMPK phosphorylation and HSP72 expression. Proinflammatory cytokines reduced, by at least 50%, chronic (24 h) insulin secretion, an effect partially attenuated byl-arginine. Acute insulin secretion was robustly stimulated byl-arginine but this effect was abolished in the presence of cytokines. We conclude thatl-arginine can stimulate β-cell insulin secretion, antioxidant and protective responses, enabling increased functional integrity of β-cells and islets in the presence of proinflammatory cytokines. Glucose consumption and intermediary metabolism were increased byl-arginine. These results highlight the importance ofl-arginine availability for β-cells during inflammatory challenge.

National Institute of Hormones and Women’s Health (INCT), Porto Alegre, Rio Grande do Sul, BrazilThe vascular endothelium plays a key role in arterial wall homeostasis by preventing atherosclerotic plaque formation. A primary causalfactor of endothelial dysfunction is the reactive oxygen species. Aerobic exercise is ascribed as an important adjuvant therapy inendothelium-dependent cardiovascular disease. However, little is known about the effects of concurrent (aerobic+strength) training on that.For a comparison of the effects of aerobic and concurrent physical training on endothelial function, oxidative stress parameters and theimmunoinflammatory activity of monocytes/macrophages, 20 adult male volunteers of middle age were divided into a concurrent training(CT) programme group and an aerobic training group. The glutathione disulphide to glutathione ratio (GSSG/GSH) and plasma lipoperoxide(LPO) levels, as well as flow-mediated dilation (FMD), monocyte/macrophage functional activity (zymosan phagocytosis), body lipidprofiles, aerobic capacity (maximal oxygen uptake) and strength parameters (one-repetition maximum test), were measured before and afterthe exercise training programmes. The CT exhibited reduced acute effects of exercise on the GSSG/GSH ratio, plasma LPO levels andzymosan phagocytosis. The CT also displayed improved lipid profiles, glycaemic control, maximal oxygen uptake and one-repetitionmaximum test values. In both the aerobic training and the CT, training improved the acute responses to exercise, as inferred from a decreasein the GSSG/GSH ratios. The aerobic sessions did not alter basal levels of plasma LPO or macrophage phagocytic activity but improvedFMD values as well as lipid profiles and glycaemic control. In summary, both training programmes improve systemic redox status andantioxidant defences. However, the aerobic training was more efficient in improving FMD in the individuals studied. Copyright # 2011John Wiley & Sons, Ltd.key words—oxidative stress; endothelial function; physical training; immune response; exercise

Disorders concerning the metabolism of plasma and intracellular lipids are hallmarks of atherosclerosis. However, failures in proper control of intracellular cholesterol balance, rather than simple cholesterol overloading due to augmented uptake, could fuel atherogenesis. Therefore, the understanding of atherosclerosis-associated lipid alterations, which feed an inflammatory microenvironment in the arterial wall, requires the meticulous investigation of several aspects of lipid synthesis, uptake and export from cells. In this regard, the presence of reactive cysteines in transcription factors and key enzymes of lipid metabolism may dictate cholesterol accumulation, and therefore the progression of vascular disease. The strong inhibitory effect of cysteine-reactant anti-inflammatory cyclopentenone prostaglandins (CP-PGs) over atherosclerosis progression in vivo (LipoCardium technology) symbolizes a new concept of atherosclerosis and its treatment. Results from this laboratory and those from other research groups have unraveled a novel facet in prostaglandin research in that CP-PGs may act as redox signals that guide lipid metabolism in atherosclerosis. By modifying enzymes ( e.g. , HMG-CoA reductase, ACAT and cholesteryl ester hydrolases) and transcription factors ( e.g. , NF-κB and Keap1) involved in inflammation and lipid metabolism, CP-PGs (especially those of A-series) induce pivotal changes in glutathione and lipid metabolism that completely arrest atherosclerosis progression. Hence, pharmacological manipulation of lipid metabolism by CP-PGs may be a novel and invaluable strategy for treating atherosclerosis. Also, a better understanding of why CP-PGs do not resolve inflammation physiologically may explain many unsolved questions and yield insights into atherogenesis and its termination.

Prevention of type 1 diabetes mellitus (T1DM) requires early intervention in the autoimmune process directed against beta-cells of the pancreatic islets of Langerhans, which is believed to result from a disorder of immunoregulation. According to this concept, a T-helper lymphocyte of type 1 (Th1) subset of T-lymphocytes and their cytokine products, the type 1 cytokines [e.g. interleukin 2 (IL-2), interferon gamma (IFN-gamma) and tumour necrosis factor beta (TNF-beta)] prevail over immunoregulatory (anti-inflammatory) Th2 subset and its cytokine products, i.e. type 2 cytokines (e.g. IL-4, IL-6 and IL-10). This allows type 1 cytokines to initiate a cascade of immune/inflammatory processes in the islet (insulitis), culminating in beta-cell destruction. Activation of sympathetic-corticotropin-releasing hormone (CRH) axis by psychological stress induces specifically Th1 cell overactivity that determines enhanced glutamine utilization and consequent poor L-arginine supply for nitric oxide (NO)-assisted insulin secretion. This determines the shift of intraislet glutamate metabolism from the synthesis of glutathione (GSH) to that of L-arginine, leading to a redox imbalance that activates nuclear factor kappaB exacerbating inflammation and NO-mediated cytotoxicity. Physical exercise is capable of inducing changes in the pattern of cytokine production and release towards type 2 class and to normalize the glutamine supply to the circulation, which reduces the need for glutamate, whose metabolic fate may be restored in the direction of GSH synthesis and antioxidant defence. Also, the 70-kDa heat shock protein (hsp70), which is immunoregulatory, may modulate exercise-induced anti-inflammation. In this work, we envisage how exercise can intervene in the mechanisms involved in the autoimmune process against beta-cells and how novel therapeutic approaches may be inferred from these observations.

Background:Since exercise increases the production of reactive oxygen species in different tissues, the objective of this study is to evaluate, compare and correlate the acute effects of aerobic and resistance exercise in circulatory markers of oxidative stress and acylated ghrelin (AG) in postmenopausal women.Methods:Ten postmenopausal women completed different protocols: a control session (CON), an aerobic exercise session (AERO); and a single-set (SSR) or 3-set (MSR) resistance exercise protocol.Results:After exercise, both MSR (P = .06) and AERO (P = .02) sessions showed significant increased lipid peroxidation compared with baseline levels. CON and SSR sessions showed no differences after exercise. No differences were found between sessions at any time for total glutathione, glutathione dissulfide or AG concentrations.Conclusions:Exercise significantly increased lipid peroxidation compared with baseline values. As pro oxidant stimuli is necessary to promote chronic adaptations to the antioxidant defenses induced by exercise, our findings are important to consider when evaluating exercise programs prescription variables aiming quality of life in this population.

The 70 kDa heat-shock protein (HSP70) family is important for a dynamic range of cellular processes that include protection against cell stress, modulation of cell signalling, gene expression, protein synthesis, protein folding and inflammation. Within this family, the inducible 72 kDa and the cognate 73 kDa forms are found at the highest level. HSP70 has dual functions depending on location. For example, intracellular HSP70 (iHSP70) is anti-inflammatory whereas extracellular HSP70 (eHSP70) has a pro-inflammatory function, resulting in local and systemic inflammation. We have recently identified a divergence in the levels of eHSP70 and iHSP70 in subjects with diabetes compared with healthy subjects and also reported that eHSP70 was correlated with insulin resistance and pancreatic β-cell dysfunction/death. In the present review, we describe possible mechanisms by which HSP70 participates in cell function/dysfunction, including the activation of NADPH oxidase isoforms leading to oxidative stress, focusing on the possible role of HSPs and signalling in pancreatic islet α- and β-cell physiological function in health and Type 2 diabetes mellitus.

Hot flashes, which involve a tiny rise in core temperature, are the most common complaint of peri- and post-menopausal women, being tightly related to decrease in estrogen levels. On the other hand, estradiol (E2) induces the expression of HSP72, a member of the 70 kDa family of heat shock proteins (HSP70), which are cytoprotective, cardioprotective, and heat inducible. Since HSP70 expression is compromised in age-related inflammatory diseases, we argued whether the capacity of triggering a robust heat shock (HS) response would be still present after E2 withdrawal. Hence, we studied the effects of HS treatment (hot tub) in female Wistar rats subjected to bilateral ovariectomy (OVX) after a 7-day washout period. Twelve h after HS, the animals were killed and aortic arches were surgically excised for molecular analyses. The results were compared with oxidative stress markers in the plasma (superoxide dismutase, catalase, and lipoperoxidation) because HSP70 expression is also sensitive to redox regulation. Extracellular (plasma) to intracellular HSP70 ratio, an index of systemic inflammatory status, was also investigated. The results showed that HS response was preserved in OVX animals, as inferred from HSP70 expression (up to 40% rise, p < 0.01) in the aortas, which was accompanied by no further alterations in oxidative stress, hematological parameters, and glycemic control either. This suggests that the lack of estrogen per se could not be solely ascribed as the unique source of low HSP70 expression as observed in long-term post-menopausal individuals. As a consequence, periodic evaluation of HSP70 status (iHSP70 vs. eHSP70) may be of clinical relevance because decreased HS response capacity is at the center of the onset of menopause-related dysfunctions.

The prevalence of diabetes mellitus (DM) is increasing worldwide, a consequence of the alarming rise in obesity and metabolic syndrome (MetS). Oxidative stress and inflammation are key physiological and pathological events linking obesity, insulin resistance, and the progression of type 2 DM (T2DM). Unresolved inflammation alongside a “glucolipotoxic” environment of the pancreatic islets, in insulin resistant pathologies, enhances the infiltration of immune cells which through secretory activity cause dysfunction of insulin-secretingβ-cells and ultimately cell death. Recent molecular investigations have revealed that mechanisms responsible for insulin resistance associated with T2DM are detected in conditions such as obesity and MetS, including impaired insulin receptor (IR) signalling in insulin responsive tissues, oxidative stress, and endoplasmic reticulum (ER) stress. The aim of the present review is to describe the evidence linking oxidative stress and inflammation with impairment of insulin secretion and action, which result in the progression of T2DM and other conditions associated with metabolic dysregulation.