Increased Adiposity, Dysregulated Glucose Metabolism and Systemic Inflammation in Galectin-3 KO Mice

PMCID: PMC3579848This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Annexin A1 Regulates Adiposity in Mice

Annexin A1 (ANXA1) is a glucocorticoid- (GC-) induced protein that mediates at least a part of the anti-inflammatory actions of these hormones. However, it is unknown whether ANXA1 also mediates some of the metabolic functions of GC. The role of this protein in adipose tissue metabolism and inflammation needs to be carefully investigated. Our aim was to study the effect of ANXA1 deficiency on markers of adiposity in mice by measuring body weight (BW), body composition, and gene expression of metabolic factors in mice fed both chow and high fat diet (HFD). We also aimed at evaluating the effect of ANXA1 deficiency on gene expression of pro- and anti-inflammatory mediators in visceral adipose tissue (VAT). Annexin A1 Knock-out (KO) mice developed significantly higher adiposity compared to while type (WT) mice. The effect of ANXA1 deficiency on adiposity was independent of food intake, as no significant difference was observed in food intake between any of the mice groups. In addition, we found a significant elevation in the gene expression levels of ANXA1 in WT-HFD mice as compared to WT-chow mice, with no changes in expression of the ANXA1 receptor, formyl peptide receptor-2 (FPR2), between the four groups of mice. In terms of glycemic control, KO-HFD mice had significantly elevated fasting blood glucose and plasma insulin as compared to KO-chow and WT-HFD mice, while no significant difference was observed comparing WT-HFD to WT-chow mice,. Furthermore, KO mice in both diet groups developed significant insulin resistance compared to both WT groups as evaluated by insulin tolerance test (ITT). Although KO-HFD mice showed a trend towards glucose intolerance in the glucose tolerance test (GTT), the difference to other groups of mice was not significant. A trend towards elevated plasma levels of corticosterone in the KO mice on both diets compared to WT mice was observed, which could help explain the increased susceptibility of ANXA1 KO mice to obesity. Additionally, gene expression of 11-beta hydroxy-steroid dehydrogenase (11βHSD1) in VAT was observed in the KO-HFD mice compared to WT-HFD mice, which might have led to increased intracellular activation of GC. However, expression of the hormone sensitive lipase (HSL), adipose triglyceride lipase (ATGL) and of peroxisome proliferator activated receptor-gamma (PPAR-γ) was comparable between the two strains. Furthermore, no significant difference in VAT inflammation was found between KO and WT mice. In conclusion, in a mouse model of DIO, we show that deletion of ANXA1 leads to metabolic alterations that switch the obesity-resistant phenotype of female BALB/c mice towards increased adiposity and insulin resistance when compared to sex-, age-, and diet-matched WT mice. Further studies are needed to replicate our findings and explain the mechanisms behind the protective roles of ANXA1 against obesity and insulin resistance

Increased adiposity in annexin A1-deficient mice.

Production of Annexin A1 (ANXA1), a protein that mediates the anti-inflammatory action of glucocorticoids, is altered in obesity, but its role in modulation of adiposity has not yet been investigated. The objective of this study was to investigate modulation of ANXA1 in adipose tissue in murine models of obesity and to study the involvement of ANXA1 in diet-induced obesity in mice. Significant induction of ANXA1 mRNA was observed in adipose tissue of both C57BL6 and Balb/c mice with high fat diet (HFD)-induced obesity versus mice on chow diet. Upregulation of ANXA1 mRNA was independent of leptin or IL-6, as demonstrated by use of leptin-deficient ob/ob mice and IL-6 KO mice. Compared to WT mice, female Balb/c ANXA1 KO mice on HFD had increased adiposity, as indicated by significantly elevated body weight, fat mass, leptin levels, and adipocyte size. Whereas Balb/c WT mice upregulated expression of enzymes involved in the lipolytic pathway in response to HFD, this response was absent in ANXA1 KO mice. A significant increase in fasting glucose and insulin levels as well as development of insulin resistance was observed in ANXA1 KO mice on HFD compared to WT mice. Elevated plasma corticosterone levels and blunted downregulation of 11-beta hydroxysteroid dehydrogenase type 1 in adipose tissue was observed in ANXA1 KO mice compared to diet-matched WT mice. However, no differences between WT and KO mice on either chow or HFD were observed in expression of markers of adipose tissue inflammation. These data indicate that ANXA1 is an important modulator of adiposity in mice, with female ANXA1 KO mice on Balb/c background being more susceptible to weight gain and diet-induced insulin resistance compared to WT mice, without significant changes in inflammation

Validity and reproducibility of a food frequency questionnaire to assess macro and micro-nutrient intake among a convenience cohort of healthy adult qataris

This study aimed at developing a valid culture-sensitive quantitative food frequency questionnaire (FFQ) for Qatari adults. A convenient sample of healthy Qataris (n = 107) were recruited from family members of Qatar University students. The Diet History Questionnaire II of the US National Cancer Institute was translated to Arabic language, back-translated to English, pilot tested, and then modified accordingly to be used in Qatari setting. Participants were asked to complete the translated version of the FFQ. This FFQ was then validated against three 24 h diet recall (24 hDR) including a weekend day. Participants were asked to complete the FFQ again after one-month period to measure its repeatability. Dietary data were analyzed using the dietary analysis software ESHA. The validity and reliability of FFQ were assessed by comparing the median intake of nutrients and foods and by calculating the Pearson correlation coefficients. The median nutrient intakes assessed by the second FFQ were higher than that reported in the baseline FFQ1 except for fat. The percentage of increase varies between 1.5% and 96%. Results of the second FFQ indicated an overestimation of intake for most nutrients (macro and micro). Macronutrient intakes assessed by the two FFQ and 24 hDR were strongly correlated. The correlation coefficients for micronutrient intakes between FFQ2 and 24hDR were lower than that of the two FFQs except for calcium (r = 0.55) and sodium (r = 0.643). They ranged from (−0.17) for fluorine to (0.643) for sodium. The agreement rates for classifying macronutrient intakes into same or adjacent quartile were between 79.4% and 100% for the two FFQs and between 71% and 100% for the second FFQ and 24hDR. The reported consumption of food groups estimated by FFQ2 was significantly higher than that reported by FFQ1. In conclusion, the developed FFQ was sufficiently valid to assess energy and macronutrients but not micronutrients. The reliability was adequate for most nutrients

Corticosterone and 11βHSD1 levels in WT and ANXA1 KO mice.

<p><u>Panel A</u>: Plasma corticosterone levels in fed mice (n = 5 – 13). <u>Panel B</u>: Expression of 11βHSD1 mRNA in VAT of fed mice (n = 4 – 5). *p<.05 vs. respective diet-matched WT group, p<.05 vs. WT-Chow, #p<.05 vs. KO-Chow. Data are mean ± SEM.</p

Modulation of ANXA1 expression in adipose tissue.

<p><u>Panel A</u>: Time course of ANXA1 mRNA expression in VAT and SAT of male C57BL6 mice fed chow or HFD for 5, 9 or 13 weeks. Data are expressed as fold difference vs. the respective tissue in chow mice at 5 weeks. ***p<0.001 vs. respective tissue in chow mice. <u>Panel B</u>: Expression of ANXA1 mRNA in VAT SVF and adipocytes of male C57BL6 mice fed chow or HFD for 13 weeks (n = 9). *p<0.05, ***p<0.001 vs. respective fraction in chow mice. <u>Panels C and D</u>: Number (Panel C) and Mean Fluorescence Intensity (Panel D) of ANXA1⁺ cells per mg of tissue in the F4/80^- and F4/80⁺ populations from VAT of male C57BL6 mice fed chow or HFD for 13 weeks evaluated by flow cytometry (n = 5). ***p<0.001 vs. respective cell population in chow mice. <u>Panel E</u>: Expression of ANXA1 mRNA at eight weeks of age in VAT of male WT and <i>ob/ob</i> mice fed chow diet (n = 3). <u>Panel F</u>: Expression of ANXA1 mRNA in VAT of male WT and IL-6 KO mice fed chow or HFD for 13 weeks (n = 3 – 5). **p<.005 vs. WT-HFD, p<.05 vs. WT-Chow. Data are mean ± SEM.</p

Deficiency of ANXA1 modulates adiposity in female Balb/c mice.

<p><u>Panel A</u>: Body weight in grams, (n = 14 – 20). <u>Panel B</u>: Fat mass in grams measured by DXA. <u>Panel C</u>: Percentage of fat mass to BW (n = 14 – 19). <u>Panel D</u>: Plasma leptin levels (n = 13 – 17). <u>Panel E</u>: Leptin mRNA expression in VAT (n = 4 – 5). <u>Panel F</u>: Plasma adiponectin levels (n = 13 – 17). <u>Panel G</u>: Adiponectin mRNA expression in VAT (n = 5). <u>Panel H</u>: PPARγ mRNA expression in VAT (n = 4 – 5). <u>Panel I</u>: Lean mass in grams measured by DXA. <u>Panel J</u>: Median adipocyte size in VAT and SAT (n = 4 – 5), H&E-stained slides for VAT and SAT magnified to 10X. *p<.05 vs. respective diet-matched WT group, p<.05 vs. WT-Chow, #p<.05 vs. KO-Chow. Data are mean ± SEM.</p

Expression of markers of lipolysis in VAT.

<p><u>Panel A</u>: Expression of ATGL, HSL, and Galectin-12 mRNA in fasted mice and FAS, ACC, and SREBF1 mRNA in fed mice in VAT (n = 5). <u>Panel B</u>: Ratio of pHSL to HSL protein in fasted mice in VAT by western blot (n = 3). *p<.05 vs. respective diet-matched WT group, p<.05 vs. WT-Chow, #p<.05 vs. KO-Chow. Data are mean ± SEM.</p

Markers of VAT inflammation in WT and ANXA1 KO mice.

<p>Expression of CD68, IL-6, IL-1β, CCL2, and IL-10 mRNA in VAT (n = 8 – 10). p<.05 vs. WT-Chow, #p<.05 vs. KO-Chow. Data are mean ± SEM.</p

Novel in vitro and in vivo anti-Helicobacter pylori effects of pomegranate peel ethanol extract

Background and Aim: Interest in plants with antimicrobial properties has been revived due to emerging problems associated with using antibiotics to eradicate Helicobacter pylori. Accordingly, this study aims to assess the antibacterial effects of Punica granatum and the possible synergistic effect of its extract along with metronidazole against H. pylori. Materials and Methods: Pomegranate peel ethanol extracts (PPEE) was tested against a control strain of H. pylori (NCTC 11916) in vitro and in vivo in female Wistar rats. Moreover, the synergistic effect of PPEE in combination with metronidazole was tested in vitro. Results: The PPEE exhibited a remarkable activity against H. pylori with a minimum inhibitory concentration (MIC) of 0.156 mg/mL. Furthermore, the extract exhibited a pronounced urease inhibitory activity (IC50 ∼6 mg/mL) against the tested strain. A synergistic effect between PPEE and metronidazole was also observed (fractional inhibitory concentrations <0.5). Oral treatment of rats with PPEE for 8 days produced a significant reduction in H. pylori gastritis and a significant decrease in both lymphocytic and positive chronicity. Conclusion: Pomegranate extract is probably safe and represents a potential alternative and complementary therapy for reducing H. pylori associated with gastric ulcers