The effect of dietary lipid manipulation on murine splenic lymphocytes apoptosis and heat shock protein over expression

Effects of eicosapentaenoic acid supplementation on heat shock protein 27, glycemic status and anthropometric indices in type 2 diabetes patients

Purpose

Heat shock proteins (HSP-27) are reported to be involved in the pathophysiology of diabetes complications. The purpose of the current study is to assess the effects of eicosapentaenoic acid (EPA) supplementation on serum HSP-27, glycemic status and anthropometric indices in type 2 diabetes mellitus (T2DM) patients.

Methods

Thirty-six patients with T2DM were randomly allocated to obtain 2 g per day EPA (n = 18) or placebo (n = 18) for 8 weeks in a randomized, double-blind, placebo-controlled clinical trial. Fasting serum levels of HSP 27, fasting blood sugar, hemoglobin A1C, as well as anthropometric indices were measured.

Results

EPA supplementation reduces the serum level of HSP 27 in the EPA group compared with the placebo (P < 0.03). Although waist circumference (WC) decreased significantly in the EPA group at the end of the trial (P < 0.02), there was no significant difference in weight, WC, body mass index (BMI), and glycemic markers in both groups after intervention (P > 0.05).

Conclusions

We found that EPA supplementation reduces HSP 27 serum level in T2DM patients. However, future large-scale trials are needed.

Impairing of gill health through decreasing immune function and structural integrity of grass carp (Ctenopharyngodon idella) fed graded levels dietary lipids after challenged with Flavobacterium columnare

The current study conducted to investigate the hypothesis that low or excess levels of lipids increased the gill rot morbidity through impairing the immune function and structural integrity in the gill of grass carp (Ctenopharyngodon idella). A total of 540 young grass carp with an average initial weight of 261.41 ± 0.53 g were fed diets containing six graded levels of lipids at 0.59%, 2.14%, 3.60%, 5.02%, 6.66% and 8.01% diets for 8 weeks. After the growth trial, fish were challenged with Flavobacterium columnare for 3 days. The results indicated that compared with optimal lipids supplementation (2.14%-8.01% lipids diets), low or excess levels of lipids impaired fish immune function through declining the activities of humoral compounds, down-regulated the mRNA levels of anti-inflammatory cytokines, inhibitor of κBα (IκBα) and ribosomal p70S6 kinase (S6K1), and up-regulated pro-inflammatory cytokines, nuclear factor κB p65 (NF-κB p65) (not p52), IκB kinase α (IKKα) (not IKKβ), IKKγ and eIF4E-binding protein (4EBP) in the gill of young grass carp. In addition, low or excess levels of lipids decreased young grass carp physical barrier function through down-regulating the mRNA levels of ZO-1 (rather than ZO-2b), Claudin b, c, 3, 12, 15a, 15b, 7b, 7a and Occludin through MAPKK 6/p38 MAPK/MLCK signaling molecules, decreasing antioxidant ability via Kelch-like ECH-associating protein 1a (Keap1a)/NF-E2-related factor 2 (Nrf2) signaling molecules, and down-regulating the mRNA levels of B-cell lymphoma-2 (Bcl-2) and inhibitor of apoptosis protein (IAP) and up-regulating the mRNA levels of apoptotic protease activating factor-1 (Apaf-1), Caspase-3, -8 and -9 and Fas ligand (FasL) in the gill of grass carp. Based on the quadratic regression analysis for the gill rot morbidity, C3 and MDA contents, the dietary lipids requirements for young grass carp have been estimated to be 5.60%, 6.01% and 4.58% diets.

Dietary low or excess levels of lipids reduced growth performance, and impaired immune function and structure of head kidney, spleen and skin in young grass carp (Ctenopharyngodon idella) under the infection of Aeromonas hydrophila

Our study explored the effect of dietary lipids on growth and immunity and structure (head kidney, spleen and skin) of young grass carp (Ctenopharyngodon idella). A total of 540 young grass carp with an average initial weight of 261.41 ± 0.53 g were fed diets containing six graded levels of lipids at 5.9-80.1 g/kg diet for 8 weeks. After that, a challenge trial was conducted by injection of Aeromonas hydrophila over 2 weeks. The results indicated that compared with optimal lipids supplementation, low and excess levels of lipids down-regulated the mRNA levels of antimicrobial peptides, anti-inflammatory cytokines, inhibitor of κBα (IκBα) and ribosomal p70S6 kinase (S6K1), and up-regulated pro-inflammatory cytokines, nuclear factor κB p65 (NF-κB p65), NF-κB c-Rel (not p52), IκB kinase α (IKKα), IKKβ, IKKγ, and eIF4E-binding protein (4EBP) mRNA levels in the head kidney and spleen of young grass carp (P < 0.05). Low or excess levels of lipids also increased reactive oxygen species (ROS) production and malondialdehyde (MDA) and protein carbonyl (PC) contents, reduced the activities of antioxidant enzymes (P < 0.05), down-regulate the relative mRNA levels of antioxidant enzymes and NF-E2-related factor 2 (Nrf2), and up-regulated the expression levels of Kelch-like ECH-associating protein 1a (Keap1a) and Keap1b in the head kidney and spleen. In addition, low or excess levels of lipids down-regulated the mRNA levels of B-cell lymphoma-2 (Bcl-2) and inhibitor of apoptosis protein (IAP) in the head kidney and spleen, whereas up-regulated the mRNA levels of apoptotic protease activating factor-1 (Apaf-1), caspase 3, 7, 8 and 9 mRNA levels in the head kidney and spleen and Fas ligand (FasL) mRNA levels in the spleen of young grass carp, suggesting that low or excess levels of lipids could decrease the head kidney and spleen immune function, induce oxidative damage and apoptosis and impair antioxidant system of young grass carp. At last, low or excess levels of lipids also impaired the immune function and structure in the skin of young grass carp. Based on the quadratic regression analysis for PWG, skin haemorrhage and lesions morbidity and IgM content, the dietary lipids requirements for young grass carp were estimated to be 43.7, 60.2, 55.0 and 52.1 g/kg diet, respectively.

Saffron in metabolic syndrome: its effects on antibody titers to heat-shock proteins 27, 60, 65 and 70

BACKGROUND

The metabolic syndrome is the most important risk factor for cardiovascular disease. The heat shock proteins (HSPs) are highly conserved families of proteins expressed by a number of cell types following exposure to stressful environmental conditions include several known risk factors for cardiovascular disease. Recent studies have shown the potential of constituents of saffron in the treatment of atherosclerosis. We aimed on investigating the effect of saffron on antibody titers to HSP in patients with metabolic syndrome.

METHODS

This was a randomized, placebo-controlled clinical trial. One-hundred and five subjects with metabolic syndrome were randomly allocated to one of the three groups: the case group received 100 mg/day saffron, the placebo control group received a capsule of placebo and a non-placebo control group received no capsule, for 12 weeks.

RESULTS

Antibodies against heat shock proteins 27, 60, 65 and 70 were determined in all patients before (week 0) and after (week 6 and 12) intervention. At 12 weeks, saffron produced a significantly decrease in AntiHSP27, 70 levels. Saffron can decrease AntiHSP27, 70 levels in patients with metabolic syndrome.

CONCLUSIONS

The results of this study indicate the efficacy of saffron in the improvement of some markers of autoimmunity HSPs in patients with metabolic syndrome.

Effects of intravenous triacylglycerol emulsions on lymphocyte responses to mitogens in fasted dairy cows undergoing intense lipomobilization

The objective of the study was to assess the effects of intravenous infusion of triacylglycerol (TAG) emulsions derived from different lipid sources on responses to mitogens of peripheral blood mononuclear cells (PBMC) isolated from fasted dairy cows. Six multiparous, non-pregnant, non-lactating Holstein cows were used in a replicated 3×3 Latin Square design. For 4 d, cows were fasted and infused intravenously with a 20% TAG emulsions derived from tallow (TA), linseed oil (LO) or fish oil (FO). Fasting was employed to induce energy deficit and lipid mobilization. Emulsions were administered for 20 to 30 min every 4 h throughout the 4 d fast at a rate of 0·54 g TAG/kg BW/d. Blood samples were taken before the first infusion, and then every 24 h during the fast. Blood was utilized to assess DNA synthesis, IgM and interferon-gamma (IFN-γ) secretion by PBMC stimulated with mitogens. In TA infused cows there was a decline of PBMC ability to respond to mitogens, which was significant 48 h after initiation of the infusion period for DNA synthesis and IFN-γ secretion. In LO or FO infused cows, PBMC responses to mitogens were not altered during the infusion period, and in some cases PBMC responses to mitogen was improved at 72 and 96 h after initiation of treatments. Effects of TAG infusion on PBMC responses to mitogens depended on the lipid source suggesting that LO or FO can attenuate the negative effects of fasting on immune functions.

Influence of high-fat feeding on both naive and antigen-experienced T-cell immune response in DO10.11 mice

Obesity is becoming one of the most serious public health problems in industrialized societies, due to the profound changes in lifestyle, and notably in nutrition. Beside diabetes, cardiovascular diseases or hypertension, increased susceptibility to infection is one of the pathological consequences of being overweight. In this paper, we have assessed the influence of a high-fat diet (HFD) rich in saturated fatty acids on the immune system of DO11.10 mice, which are transgenic for a T-cell receptor specifically recognizing a peptide of ovalbumin. We showed that the specific T-cell immune response was impaired by high-fat feeding, and that the expression of this defect is different depending on whether T cells are naive or Ag experienced. Indeed, on in vitro ovalbumin stimulation, spleen T cells from naive HFD-fed transgenic mice showed proliferation similar to that of cells from standard diet (SD)-fed mice, but exhibited a strong inflammatory profile as shown by the markedly increased IFN-gamma/IL-4 ratio. Inversely, spleen T cells from ovalbumin-immunized HFD mice were impaired in their Ag-dependent proliferation compared to cells from SD mice. By co-culture experiments, we showed that both T cells and antigen-presenting cells were involved in this impairment. Moreover, in ovalbumin-immunized HFD animals, a trend towards Th2 response was noted, compared to immunized SD mice. This data implies that naive T cells could participate actively in the low-grade systemic inflammation observed in overweight patients. Moreover, the impaired activity of Ag-experienced T cells could have major consequences both in defence against infection and/or in vaccination protocols.

Dietary antioxidants and fat are associated with plasma antibody titers to heat shock proteins 60, 65, and 70 in subjects with dyslipidemia

BACKGROUND

The heat shock proteins (HSPs) are protein chaperones. Higher titers of antibody to HSPs (anti-HSPs) have been reported in atherosclerosis, which may contribute to immunoactivation in this process.

OBJECTIVE

We investigated whether dietary antioxidants and fat intake are associated with changes in anti-HSP titers in dyslipidemic subjects.

DESIGN

Patients (n = 238) were recruited from hospital lipid clinics. Control subjects (n = 188) were recruited from university and hospital employees. Food-frequency questionnaires were used to estimate dietary antioxidants and fat.

RESULTS

Dyslipidemic patients had significantly higher titers of anti-HSPs than did control subjects; expressed in medians and interquartile ranges of absorbance units, anti-HSP-60 titers were 0.27 (0.18-0.37) and 0.22 (0.16-0.30), anti-HSP-65 titers were 0.45 (0.28-0.79) and 0.31 (0.22-0.50), and anti-HSP-70 titers were 0.22 (0.17-0.30) and 0.19 (0.13-0.27), respectively. Median and interquartile ranges of serum concentrations of C-reactive protein [1.25 (0.42-3.26) and 0.58 (0.17-1.42)] and mean (+/-SEM) concentrations of vitamin E (16.36 +/- 0.31 and 14.08 +/- 0.38) were also significantly higher in patients than in control subjects, respectively. In dyslipidemic patients, the major dietary predictors of the variability in anti-HSP-60 titers were vitamin C (P = 0.005), vitamin E (P = 0.04), and total fat (P = 0.009) intakes; for anti-HSP-65 titers, vitamin C was the major predictor (P = 0.002). These findings remained significant after adjustment for confounding factors.

CONCLUSIONS

Anti-HSP-60, -65, and -70 titers are significantly higher in dyslipidemic patients with or without established coronary disease. Our data indicate an association between dietary constituents and the immune response to HSPs in dyslipidemic subjects.

Effects of dietary fatty acids on burn-induced immunosuppression

Previous studies from our laboratory established that low-fat diets prevent immunosuppression and reduce oxidative stress after a thermal injury. The purpose of the present study was to test the hypothesis that the type of dietary fatty acid influences splenocyte proliferation and oxidative stress following a burn injury. Female C3H/HeN mice were fed ad libitum six experimental diets (5% w/w lipids) differing in fatty acid composition for 10 days following a burn injury. Compared to the controls, burned mice fed whichever diet showed lower lymphoproliferative responses to concanavalin-A (Con-A) and lipopolysaccharide (LPS) (p<0.01), but not to an anti-T cell receptor monoclonal antibody (H-57). In burned animals, nitric oxide (NO) concentration was negatively correlated to the proliferation induced by Con-A (p<0.01) or LPS (p<0.05). These results suggest that: (1) dietary fatty acid type does not influence the splenocyte proliferation or oxidative stress and (2) NO production is involved in the immunosuppression following burn injury.

Modulatory effects of dietary lipids on immune system functions

Dietary lipid manipulation may affect a great number of immune parameters, such as lymphocyte proliferation, cytokine synthesis, natural killer (NK) cell activity, phagocytosis and so on. The immunomodulation induced by dietary fatty acids may be applied in the amelioration of inflammatory disorders, such as autoimmune diseases. However, the mechanisms that participate in these processes are still poorly understood. It is probable that modulation of immune system by fatty acids of the diet may occur by alteration of membrane fluidity, lipid peroxide formation, eicosanoid production or regulation of gene expression. However, recent studies have reported the effects of several free fatty acids on apoptosis induction of in vitro cultures. In fact, a possible explanation of the effects that fatty acids promote on the immune system cells could be associated with an apoptotic process performed in an irreversible way. In vivo studies have demonstrated the ability of fatty acids to alter the survival of animals fed diets containing oils and infected with a pathogenic bacterium. Experimental infection in animals fed dietary lipids produces a modification of resistance to micro-organisms. The present review analyses all of these parameters that dietary fatty acids are capable of altering in order to modify the immune response. Further studies will be needed to establish the mechanisms involved in immune system regulation, reduction of symptoms derived from autoimmune pathologies and so on.

Determination of natural resistance of mice fed dietary lipids to experimental infection induced by Listeria monocytogenes

Current understanding based on the effect of dietary lipid manipulation upon immune system function indicates that fatty acids are involved in the modulation of the immune response through different and complex pathways. Reduction of several immune parameters by fatty acid action may be applied in the treatment of diseases characterised by an overactivation of the immune system. As a consequence, a reduction of host resistance against infectious agents has been reported in animals fed dietary lipids. The present study confirms the action of dietary lipids on the survival of mice infected with the pathogenic bacterium Listeria monocytogenes. A significant increase in peritoneal cells from mice fed a hydrogenated coconut oil diet was found, while a significant reduction of bacterial recovery from spleens of these mice was observed in this group. In addition, both eicosanoid and phospholipase inhibitors did not promote any modification of lymphocyte proliferation from mice fed olive oil or fish oil.