Altered fatty acid pattern of phospholipids and triglycerides in the submandibular gland of omega3-depleted rats

The effects of ω-6 and ω-3 fatty-acids on early stages of mice DMBA submandibular glands tumorigenesis

The aim of this work was: to assess the impact of diets enriched in polyunsaturated fatty acids ω-3 and ω-6 families on the lipid profile of cell membrane and their effect on cycle regulation and apoptosis, evaluated by TP53 and Ki-67 expression in 9,10-dimethyl-1,2-benzanthracene (DMBA) induced tumor development in submandibular glands (SMG) in murine models. To generate tumorigenic changes, SMG mice in the experimental group were injected with 50μl of 0.5% of DMBA. Both control (no DMBA) and experimental groups of BALB/c mice were fed with: chia oil (ChO), rich in ω-3 fatty acid; corn oil (CO), rich in ω-6/ω-3 fatty acid; and safflower (SO) oil, rich in ω-6fatty acid. Results demonstrate novel differential effects of ω-3 and ω-6 PUFAs on the regulation of early tumorigenesis events in murine SMG injected with DMBA. This knowledge may help to develop chemoprotective treatments, therapeutic agents and health promotion and prevention activities in humans.

Involvement of gut microbial fermentation in the metabolic alterations occurring in n-3 polyunsaturated fatty acids-depleted mice

Backround

Western diet is characterized by an insufficient n-3 polyunsaturated fatty acid (PUFA) consumption which is known to promote the pathogenesis of several diseases. We have previously observed that mice fed with a diet poor in n-3 PUFA for two generations exhibit hepatic steatosis together with a decrease in body weight. The gut microbiota contributes to the regulation of host energy metabolism, due to symbiotic relationship with fermentable nutrients provided in the diet. In this study, we have tested the hypothesis that perturbations of the gut microbiota contribute to the metabolic alterations occurring in mice fed a diet poor in n-3 PUFA for two generations (n-3/- mice).

Methods

C57Bl/6J mice fed with a control or an n-3 PUFA depleted diet for two generations were supplemented with prebiotic (inulin-type Fructooligosaccharides, FOS, 0.20 g/day/mice) during 24 days.

Results

n-3/-mice exhibited a marked drop in caecum weight, a decrease in lactobacilli and an increase in bifidobacteria in the caecal content as compared to control mice (n-3/+ mice). Dietary supplementation with FOS for 24 days was sufficient to increase caecal weight and bifidobacteria count in both n-3/+ and n-3/-mice. Moreover, FOS increased lactobacilli content in n-3/-mice, whereas it decreased their level in n-3/+ mice. Interestingly, FOS treatment promoted body weight gain in n-3/-mice by increasing energy efficiency. In addition, FOS treatment decreased fasting glycemia and lowered the higher expression of key factors involved in the fatty acid catabolism observed in the liver of n-3/-mice, without lessening steatosis.

Conclusions

the changes in the gut microbiota composition induced by FOS are different depending on the type of diet. We show that FOS may promote lactobacilli and counteract the catabolic status induced by n-3 PUFA depletion in mice, thereby contributing to restore efficient fat storage.

Disruption of chronic cariporide treatment abrogates myocardial ion homeostasis during acute ischemia reperfusion

Cariporide, an Na/H exchanger inhibitor, is a drug with cardioprotective properties. However, chronic treatment with cariporide may modify the protein phenotype of the cardiomyocytes. Disruption of the equilibrium between a cariporide-modified phenotype and the supply of cariporide could be deleterious. The aim of this study was to test the effects of this equilibrium rupture (EqR) on cardiac function at baseline and acute ischemia reperfusion. Rats were chronically treated with cariporide (2.5 mg·kg·d) or with placebo for 21 days, after which isolated Langendorff-mode heart perfusion experiments utilized cariporide-free buffer. During this type of perfusion, the drug is rapidly cleared from the cellular environment. After 30 minutes of stabilization, the hearts were subjected to global zero-flow ischemia (25 minutes) followed by reperfusion (45 minutes). Measures of mechanical function, oxygen consumption, lactate plus pyruvate, CO2 and proton release into the coronary effluent were determined. The gene and protein expression of proton extruders was also evaluated. Chronic cariporide administration followed by EqR reduced the expression of the Na/H exchanger, increased the expression of the HCO3 or Na exchanger, decreased monocarboxylate/H carrier expression, reduced the lactate plus pyruvate release but did not change the glucose oxidation rate and mechanical function compared with baseline conditions. The resulting low glycolytic rate was associated with a stronger contracture during ischemia. During reperfusion, the early release of acidic forms was higher and redirected toward the use of the Na/H and HCO3 /Na exchangers to the detriment of the safe monocarboxylate/H carrier. Both phenomena were assumed to increase the Na uptake and activate the Na/Ca exchanger, resulting in Na and Ca overload and further cellular damage. This explains the impaired recovery of the contractile function observed in the EqR group during reperfusion. In conclusion, although cariporide is usually cardioprotective, a disruption of its chronic treatment followed by an ischemia/reperfusion event can become deleterious.