Normal Feeding Group Research Articles

Long-term impact of postnatal nutritional programming on cardiac sensitivity to ischemia-reperfusion injury in vivo and on glucose metabolism

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Fondation de France Introduction Nutritional environment during intra uterine and postnatal period has a major impact on health and disease in adulthood. The early programming of cardiometabolic risk through a postnatal overfeeding in rodents leads to a permanent increase in body weight, associated with alteration of left ventricular contractility, higher cardiac sensitivty to ischemic or chemo-toxic stresses and alterations of glucose métabolism in adulthood. However, these data have mainly obtained in young rodents and less is known for older animals. Purpose Our aim was to evaluate the impact of postnatal overfeeding (PNOF) on cardiac function, on cardiac sensitivity to ischemia-reperfusion (I-R) injury in vivo, on glucose metabolism and on metabolic profile of pericardial adipose tissue (PAT) in young (4 months), adult (6 months) and old (12 months) male mice. Methods PNOF was induced by the reduction of litter size of C57/BL6 mice immediately after birth: normally-fed group (NF) was composed of 9 male pups/mother and overfed group (PNOF) of 3 pups/mother. Echocardiography and blood sugar tests (glucose tolerance and insulin resistance) were performed at all ages. An in vivo ischemia-reperfusion injury was induced by the ligation of the left anterior descending coronary artery for 45 minutes followed by 24 h of reperfusion. PAT was harvested and weighted, in order to investigate by rt-qPCR its inflammatory status. All experiments were performed in 4-, 6- and 12-months aged mice. Results PNOF induced an early and permanent increase in body weight in PNOF group, independently of mice’s age (+23% at 24 days of life, +14% at 4 months, +23% at 6 and 12 months, compared to NF group). Echocardiographic measurements showed an alteration of left ventricular ejection fraction in mice aged from 4 months up to 12 months (-11 % on average, compared to NF groups). PNOF mice presented glucose intolerance and insulin resistance from 4 to 12 months of age. Moreover, PNOF mice had a higher PAT mass indexed to body weight with increased inflammatory status and decreased activin A mRNA expression at 6 and 12 months. Finally, PNOF induced a significant increase of infarct size at 4 months (+37%, p<0.01, n=8), 6 months (+32%, p<0.05, n=9) and 12 months (+38%, p<0,05, n=9) after cardiac surgery. Conclusion Nutritional programming through short-term PNOF induced an early and permanent overweight, an increase in pericardial fat mass with a greater inflammatory status, associated with alterations of glucose metabolism, alteration of systolic function and a higher sensitivity to ischemia reperfusion injury induced in vivo. The cellular mechanisms of these pathological modifications induced by PNOF need further exploration but could involve alterations in cardiomyocyte pathways and/or modification of global inflammatory status. Therefore, the PNOF mice model corresponds to a relevant experimental model of programmed metabolic syndrome as we known in humans.

Synergism of fermented feed and ginseng polysaccharide on growth performance, intestinal development, and immunity of Xuefeng black-bone chickens

Microbial fermented feed (MF) is considered a valuable strategy to bring advantages to livestock and is widely practiced. Oral supplementation of Ginseng polysaccharide (Gps) eliminated weight loss in chickens following vaccination. This study investigated the effects of the combined use of Gps and MF on growth performance and immune indices in Xuefeng black-bone chickens. A total of 400 Xuefeng black-bone chickens at the age of 1 day were randomly assigned to four groups. Normal feed group (Control group), ginseng polysaccharide (200 mg/kg) group (Gps group), microbially fermented feed (completely replace the normal feed) group (MF group), and microbially fermented feed and add ginseng polysaccharide just before use (MF + Gps group). Each group contained 5 pens per treatment and 20 birds per pen. The body weight and average daily gain in the Gps, MF, and MF + Gps groups increased significantly (P < 0.01), while the feed conversion ratio decreased significantly (P < 0.01). The combined use of MF and Gps showed a synergistic effect. There was no significant difference in villus height (cecal) between the experimental group and the Con group. The crypt depth of the three experimental groups exhibited a significantly lower value compared to the Control group (P < 0.05). The V/C ratio of the Gps group and MF + Gps was significantly increased (P < 0.05), but there was no significant difference in the MF group. Moreover, the diarrhea rate of the Gps and the MF + Gps groups was lower than that of the Con group, while that of the MF + Gps group decreased the mortality rate (P < 0.05). The serum tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6) levels in the MF, Gps, and MF + Gps groups decreased significantly (P < 0.01), the serum immunoglobulin G (IgG) levels increased significantly (P < 0.01), while the combination of MF and Gps had a synergistic effect. The combined use of Gps and MF not only further improved growth performance and immune parameters, but also reduced the diarrhea rate and mortality.

DEHP and DINP accelerate aging effects in male and female of Drosophila melanogaster depend on AKT/FOXO pathway

Phthalates are commonly used as plasticizers. Numerous studies have focused on endocrine, reproductive, and developmental toxicity of phthalates exposure to male organisms. In recent years, some studies looking into the aging effects of phthalates exposure in D. melanogaster showed discrepant results. In this study, we compared the different concentrations of Di(2-ethylhexyl) phthalate (DEHP) and di-isononyl phthalate (DINP) for acute and chronic treatment for different gender D. melanogaster and explored the potential mechanism of DEHP and DINP exposure. The results showed that acute exposure to DEHP or DINP at a high dose significantly decreased the lifespan of female and male D. melanogaster under HFD stress. Chronic exposure significantly decreased the lifespan of flies in all exposure groups except for the low-dose DINP exposure female group. Among them, in the normal feeding group, we found that female flies seemed to be more resistant to DEHP or DINP exposure. Meanwhile, the locomotion ability and fertility of flies exhibited a dose-dependent decline. Furthermore, phthalates did not significantly reduce the lifespan or health status of akt and foxo mutant flies in the mutant fly assays, and real-time quantitative-PCR (q-PCR) data revealed akt and foxo significant change with 10 μM DEHP or DINP treatment. This suggests that akt and foxo played a role in the process by which DEHP and DINP caused age-related declines in D. melanogaster.

The serine/threonine kinase Akt gene affects fecundity by reducing Juvenile hormone synthesis in Liposcelis entomophila (Enderlein)

The serine/threonine kinase Akt is an important component of the insulin signalling pathway (ISP) in regulating insect metabolism, growth, and reproduction. The psocid Liposcelis entomophila (Enderlein) is a distasteful stored products pest for its fecundity. However, the molecular mechanism of Akt that controls vitellogenesis and oviposition in L. entomophila remains obscure. In this study, the function of the Akt gene in the female reproduction of L. entomophila (designated as LeAkt) was characterized and investigated. LeAkt contains a 1587 bp open reading frame encoding a 529 amino acid protein that possesses a conserved Pleckstrin Homology domain (PH) and a Ser/Thr-type protein kinase (S_TKc) domain. The mRNA expression of LeAkt was the highest in female adult stages and peaked for 7-day female adults. In female adult tissues, LeAkt was highly expressed in the head and the ovary, indicating that LeAkt was closely correlated with female ovarian development. LeAkt transcription level was significantly suppressed by oral feeding on artificial diets mixed with dsRNA-LeAkt. RNAi-mediated silencing of LeAkt led to a severe inhibition of vitellogenein (Vg) expression and ovarian development, together with lower fecundity and hatchability compared to that of the normal feeding group, suggesting a critical role for LeAkt in L. entomophila reproduction. Further studies revealed that LeAkt silencing significantly decreased the mRNA levels of several signalling and biosynthetic genes in the juvenile hormone (JH) signalling pathway, such as methoprene-tolerant (LeMet), krüppel homolog 1 (LeKr-h1) and JH methyltransferase (LeJHAMT), leading to a severe inhibition of JH biosynthesis in L. entomophila female adults. These results suggested that LeAkt was affecting JH synthesis, thereby influencing Vg synthesis and ultimately L. entomophila reproduction.

Goose Hepatic IGFBP2 Is Regulated by Nutritional Status and Participates in Energy Metabolism Mainly through the Cytokine-Cytokine Receptor Pathway.

Changes in the nutritional status of animals significantly affect their health and production performance. However, it is unclear whether insulin-like growth factor-binding protein 2 (IGFBP2) mediates these effects. This study aimed to investigate the impact of changes in nutritional and energy statuses on hepatic IGFBP2 expression and the mechanism through which IGFBP2 plays a mediating role. Therefore, the expression of IGFBP2 was first determined in the livers of fasting/refeeding and overfeeding geese. The data showed that overfeeding inhibited IGFBP2 expression in the liver compared with the control (normal feeding) group, whereas the expression of IGFBP2 in the liver was induced by fasting. Interestingly, the data indicated that insulin inhibited the expression of IGFBP2 in goose primary hepatocytes, suggesting that the changes in IGFBP2 expression in the liver in the abovementioned models may be partially attributed to the blood insulin levels. Furthermore, transcriptome sequencing analysis showed that the overexpression of IGFBP2 in geese primary hepatocytes significantly altered the expression of 337 genes (including 111 up-regulated and 226 down-regulated genes), and these differentially expressed genes were mainly enriched in cytokine-cytokine receptor, immune, and lipid metabolism-related pathways. We selected the most significant pathway, the cytokine-cytokine receptor pathway, and found that the relationship between the expression of these genes and IGFBP2 in goose liver was in line with the findings from the IGFBP2 overexpression assay, i.e., the decreased expression of IGFBP2 was accompanied by the increased expression of LOC106041919, CCL20, LOC106042256, LOC106041041, and IL22RA1 in the overfed versus normally fed geese, and the increased expression of IGFBP2 was accompanied by the decreased expression of these genes in fasting versus normally fed geese, and refeeding prevented or attenuated the effects of fasting. The association between the expression of these genes and IGFBP2 was verified by IGFBP2-siRNA treatment of goose primary hepatocytes, in which IGFBP2 expression was induced by low serum concentrations. In conclusion, this study suggests that IGFBP2 mediates the biological effects induced by changes in nutritional or energy levels, mainly through the cytokine-cytokine receptor pathway.

Does size matter? Focus on the impact of reducing litter size in mice on cardio-metabolic risk and cardiac sensitivity to in vivo ischemia in adulthood

Nutritional disturbances during the postnatal period may be responsible for a predisposition, or “programming”, of increased cardio-metabolic risk in adulthood. Reducing rodent litter size is therefore crucial for perinatal nutrition that may impact long-term health. However, few data are available concerning long lasting effects of postnatal overfeeding (PNOF) in mature and/or very old animals. Our aim was to evaluate the impact of PNOF on cardiac function, cardiac sensitivity to ischemia-reperfusion (I-R) injury in vivo and on glucose metabolism in young (4 months), adult (6 months), old (12 months) and very old (18 months) male mice. PNOF was induced by litter size reduction of C57/BL6 mice 2 days after birth: normally-fed group (NF) was composed of 9 male pups/mother and overfed group (OF) of 3 pups/mother. Echocardiography and blood sugar tests (glucose tolerance and insulin resistance) have been performed at all ages. An in vivo ischemia-reperfusion injury was induced by the ligation of the anterior interventricular artery for 45 minutes followed by 24 h of reperfusion. PNOF induced an early and permanent increase of body weight in OF group, independently of mice's age (+23% at 24 days of life, +14% at 4 months, +23% at 6 and 12 months, +10% at 18 months compared to NF group). The echocardiographic measurements showed an alteration of contractile function from 6 months aged males and up to 18 months as evidenced by a decrease of the left ventricular ejection fraction (−11% for OF males from 6 to 18 months, compared to NF groups). These cardiac alterations were associated with glucose metabolism imbalance: OF males presented glucose intolerance and insulin resistance from 4 to 12 months of age. Finally, PNOF induced a significant increase of infarct size at 4 months (+37%, P < 0.01, n = 8), 6 months (+32%, P < 0.05, n = 9) and 12 months (+38%, P < 0.05, n = 9) after cardiac surgery. Nutritional programming through short-term PNOF induced early and long-lasting (up to 12–18 months) alterations of glucose metabolism and of cardiac contractility. Moreover, mice submitted to PNOF developed higher susceptibility to myocardial I-R injury in vivo at any age. Therefore, litter size is a strong determinant of long-term metabolic and cardiac status. Accordingly, adjusting litter size in rodent's group may be a necessary prerequisite in experimental procedures aimed at evaluating cardio-metabolic function.

Effect of local unstable atherosclerotic plaque on plaque formation in the carotid artery and abdominal aorta of rabbits

To analyze the effect of local unstable atherosclerotic plaque on plaque formation in the carotid and aortic arteries of rabbits. Thirty New Zealand white rabbits were randomly divided into atherosclerosis model group, highfat diet feeding group, and normal chow feeding group (blank control group). In the model group, carotid artery balloon injury was induced after 4 weeks of high-fat diet feeding. Eight weeks later, all the rabbits were euthanized for histopathological examination of the carotid artery and abdominal aorta, and the mean intimal thickness and plaque to lumen area ratio were measured using image analysis software. Venous blood samples were collected from the rabbits for blood lipid analysis. At the ends of 4, 8 and 12 weeks, the rabbits in the model group and high-fat feeding group, but not those in the blank control group, all showed significant weight gain compared with their body weight at 0 week (P < 0.05). The mean intimal thickness was significantly greater in atherosclerosis model group than in the other two groups (P < 0.05). In atherosclerosis model group, the mean intimal thickness and plaque to lumen area ratio in the injured carotid artery were significantly greater than those in the contralateral carotid artery and abdominal aorta (P < 0.05). At the end of the 12 weeks, the levels of triglyceride (TG), total cholesterol (TC), low-density cholesterol (LDL-C), high-density cholesterol (HDL-C) and highsensitivity C-reactive protein (CRP) were all significantly higher in the model group and high-fat feeding group than in the blank control group (P < 0.05); the levels of TG, TC, LDL-C, or HDL-C did not differ significantly between the model group and high-fat feeding group (P>0.05), but the level of CRP was significantly higher in arteriosclerosis model group (P < 0.05). Local unstable atherosclerotic plaque can increase the level of CRP and promote the formation of atherosclerotic plaques in the carotid artery and abdominal aorta in rabbits.

Structural characteristics of orexin receptor type 2 in Pacific abalone and its diurnal expression pattern after fasting and re-feeding

Pacific abalone (Haliotis discus hannai) is a typical nocturnal organism. To examine the circadian expression pattern of orexin receptor type 2 (OX2R) and its potential effect on the feeding behavior of abalone, the coding region sequence of OX2R that is 1215 bp in length and encodes 404 amino acids was first cloned using the rapid amplification of cDNA ends technique. A recombinant expression vector was constructed for H. discus hannai based on the OX2R protein, obtaining a recombinant protein with a molecular weight of 46 kDa. Polyclonal antibody was prepared with the purified recombinant protein used as the antigen, and the antibody titer of ≥512 K was detected by enzyme-linked immunosorbent assay. The expression levels of OX2R determined using western blotting were highest in the intestinal tract (P < 0.05), but they were not significantly different from the levels in the pedal. Immunofluorescence experiments affirmed that OX2R was widely expressed in the columnar cells of the intestinal mucosal epithelium. To further account for the relationship between the onset of feeding behavior and the expression level of OX2R in abalone, the circadian expression characteristics of OX2R were analyzed by dissecting the intestinal tissues after three days of normal feeding and fasting and following the refeeding treatment. The expression levels of OX2R in the refeeding group were significantly higher than those in the normal feeding and fasting groups at any time point (P < 0.05). The cosine curve analysis revealed that the expression levels of OX2R lost rhythmicity after fasting. Based on the quantification of behavioral data for abalone after fasting and refeeding, the cumulative movement distance and movement duration in each group followed a significant cosine rhythm (P < 0.05), which is consistent with abalone's nocturnal ecological habits. However, the cumulative movement distance and movement duration in the fasting group were significantly lower than those in the normal feeding and refeeding groups (P < 0.05). The peak phases of the cumulative movement distance and movement duration in the refeeding group (ZT08:22 and ZT08:44) shifted backward compared to the normal feeding group (ZT07:33 and ZT07:39). The above results first identified the structural characteristics and circadian expression patterns of OX2R in the marine mollusk abalone, which may reveal the molecular mechanism behind the generation of a feeding rhythm in marine nocturnal organisms and serve as a tool helping to maintain the diversity of marine benthic resources.

The gender-specific impact of starvation on mitotypes diversity in adults of Drosophila melanogaster.

In animals, starvation can increase the level of reactive oxygen species (ROS) in some tissues. Mitochondrial DNA (mtDNA) is more vulnerable to being attacked by ROS due to the lack of histone protection, leading to oxidative damage. However, whether starvation is associated with the genetic diversity of mtDNA remains unclear. Here, by using adult individuals of Drosophila melanogaster under three different feeding treatments (starvation, with the provision of only water, and normal feeding), based on the high-throughput sequencing results of the PCR amplicons of the partial sequences of the mitochondrial gene cytochrome c oxidase subunit I (mt-cox1), no significant difference in the mean number of mitochondrial haplotypes and the mean genetic distance of haplotypes within individuals were identified between the three treatment groups. Coupled with the low proportion of heterogeneous mt-cox1 sequences within each individual, it suggested that starvation had a limited impact on mitotype genetic diversity and mitochondrial function. Nevertheless, starvation could significantly increase the sequence number of haplotypes containing specific mutations, and for males with higher levels of mitochondrial heteroplasmy than females in the normal feeding group, starvation could further increase their mitochondrial heteroplasmy.

Long-term impact of postnatal overfeeding on sensitivity to ischemia-reperfusion injury in vivo and on cardio-metabolism risk

Nutritional disturbances during the postnatal period may be responsible for a predisposition, or “programming”, to increased cardio-metabolic risk and to a progressive alteration of left ventricular contractility in adulthood. However, these data have mainly obtained in young male mice, but less is known for older animals. Our aim was to evaluate the impact of postnatal overfeeding (PNOF) on cardiac function, on cardiac sensitivity to ischemia-reperfusion (I-R) injury in vivo and on glucose metabolism in young (4 months), adult (6 months) and old (12 months) male mice. PNOF was induced by the reduction of litter size of C57/BL6 mice immediately after birth: normally-fed group (NF) was composed of 9 male pups/mother and overfed group (OF) of 3 pups/mother. Echocardiography and blood sugar tests have been performed at all ages. An in vivo ischemia-reperfusion injury was induced by the ligation of the anterior interventricular artery for 45 minutes followed by 24 h of reperfusion. All experiments have been done on 4-, 6- and 12-months aged male mice. PNOF induced an early and permanent increase in body weight in OF group, independently of mice's age (+23% at 24 days of life, +14% at 4 months, +23% at 6 and 12 months, compared to NF group). The echocardiographic measurements showed an alteration of contractile function from 6 months aged males and up to 12 months as evidenced by a decrease of the left ventricular ejection fraction (−11% for OF males from 6 to 12 months, compared to NF groups). These cardiac alterations were associated with glucose metabolism imbalance: OF males presented glucose intolerance and insulin resistance from 4 to 12 months of age. To finish, PNOF induced a significant increase of infarct size at 4 months (+37%, P < 0.01, n = 8), 6 months (+32%, P < 0.05, n = 9) and 12 months (+38%, P < 0.05, n = 9) after cardiac surgery. Nutritional programming through short-term PNOF induced an early alteration of glucose metabolism and was associated with a constant higher susceptibility to myocardial I-R injury in vivo. Moreover, PNOF mice developed altered cardiac contractility at 6 months and up to 12 months. The cellular and biochemical mechanism of these pathological modifications induced by PNOF need further exploration but could involve alterations in cardiomyocyte pathways, and/or modification of global inflammatory status.

Postnatal overfeeding induces higher cardiac sensitivity to in vivo ischemia-reperfusion injury at all ages in males, but only in young females

Nutritional disturbances during the postnatal period may be responsible for a predisposition in adulthood to increased cardio-metabolic risk and a greater myocardial vulnerability to ischemia. However, these data have mainly been obtained in young male mice, but less is known for females and for old animals. Evaluate the impact of postnatal overfeeding on cardiac sensitivity after in vivo ischemia reperfusion (I-R) on both sexes and in young (4 months: mths), adult (6 mths) and mature (12 mths) mice. PNOF was induced by reduction of litter size of C57/BL6 mice immediately after birth: normally-fed group (NF) litters were composed of 9 pups/mother and overfed group litters (OF) of 3 pups/mother. The in vivo ischemia was induced by a 45 min ligation of the left anterior interventricular artery, followed by 24 hours of reperfusion, in hearts from 4-, 6- and 12-months aged male and female mice. The area at risk (AAR) was determined by Evans blue coloration and the infarct size by TTC staining. PNOF induced an early and permanent increase in body weight in OF group, for males (4 mths: +13%; 6 mths: +23%; 12 mths: +23%) and female mice (4 mths: +23%; 6 mths: +27%; 12 mths: +15%). A significant increase of infarct size was observed in hearts of overfed male mice aged at all ages (4 mths: +37%, 6 mths: +32% and 12 mths: +38% of AAR), but for females, infarct size was significant increased at 4 mths (+34%), but not at 6 and 12 mths. However, in all female groups (NF and OF) we observed a higher post-surgical mortality and a greater data variability as compared to males. Nutritional programming through short-term PNOF induced a higher susceptibility to myocardial I-R injury in vivo at all ages in male mice, but only in young females. The mechanism of this sexual dimorphism in our model is not well understood, but could involve distinct levels of cardioprotective pathways expression, related to hormonal status.

Selenium Deficiency Aggravates Heat Stress Pneumonia in Chickens by Disrupting the M1/M2 Balance

Selenium (Se) is an essential trace element found in the body. Se deficiency and M1/M2 imbalance are closely related to inflammation. Heat stress can decrease immune function and cause inflammation. In order to investigate whether Se deficiency can aggravate pneumonia caused by heat stress and the role of M1/M2 imbalance in the occurrence of pneumonia, 100 AA broilers were divided into two groups and fed the conventional diet (0.2mg/kg Se) and the Se-deficient diet (0.03mg/kg Se). After 40days of feeding, the normal feeding group was randomly divided into a control group and a heat stress group. At the same time, the Se-deficient diet feeding group was randomly divided into a low Se group and a low Se heat stress group, with 25 chickens in each group. The model was established by exposure at 40℃. Six hours later, broilers were euthanized, and their lung tissues were collected. Hematoxylin and eosin staining, immunofluorescence, quantitative real-time PCR, and western blotting were used to detect lung histopathological changes and the expression of M1/M2 markers, nuclear receptor-κB (NF-κB) pathway genes, and heat shock proteins. Meanwhile, the activity and content of oxidative stress-related indices were also detected. We found that the expression of interleukin-1β, interleukin-6, interleukin-12, and tumor necrosis factor-α was upregulated and the expression of interleukin-2, interleukin-10, and interferon-γ was downregulated. Immunofluorescence showed that the expression of CD16 was increased, the expression of CD163 was weakened, and the M1/M2 imbalance was present. In addition, the NF-κB pathway was activated by the increased expressions of heat shock proteins and oxidative stress. There was an increase in malondialdehyde, nitric oxide, and inducible nitric oxide synthase content, while the activity of total antioxidant capacity, glutathione peroxidase, catalase, and superoxide dismutase decreased, and the expression of NF-κB and cyclooxygenase-2 increased. These results suggest that low Se induces M1/M2 imbalance through oxidative stress activation of the NF-κB pathway and aggravates lung tissue inflammation caused by heat stress. This study offers a theoretical basis for exploring the pathogenesis of various kinds of inflammation induced by Se deficiency from the perspective of M1/M2 and provides a reference for the prevention of such diseases.

Postnatal overfeeding induces a higher cardiac sensitivity to in vivo ischemia-reperfusion injury at all ages in male mice, but only in young females

Nutritional disturbances during the postnatal period may be responsible for a predisposition in adulthood to increased cardio-metabolic risk and a greater myocardial vulnerability to ischemia. However, these data have mainly been obtained in young male mice, but less is known for females and for older animals. Evaluate the impact of postnatal overfeeding on: – cardiac sensitivity after in vivo ischemia-reperfusion (I-R) on both sexes; – in young (4 months), adult (6 months) and mature (12 months) mice. PNOF was induced by reduction of litter size of C57/BL6 mice immediately after birth: normally-fed group (NF) litters were composed of 9 pups/mother and overfed group litters (OF) of 3 pups/mother. The in vivo ischemia was induced by a 45 min ligation of the left anterior interventricular artery, followed by 24 hours of reperfusion, in hearts from 4-, 6- and 12-months aged male and female mice. The area at risk (AAR) was determined by Evans blue coloration and the infarct size by TTC staining. PNOF induced an early and permanent increase in body weight in OF group, for males (4 months: +13%; 6 months: +23%; 12 months: +23%) and female mice (4 months: +23%; 6 months: +27%; 12 months: +15%). A significant increase of infarct size was observed in hearts of overfed male mice aged at all ages (4 months: +37%, 6 months: +32% and 12 months: +38% of AAR), but for females, infarct size was significant increased at 4 months (+34%), but not at 6 and 12 months. However, in all female groups (NF and OF) we observed a higher post-surgical mortality and a greater data variability as compared to males. Nutritional programming through short-term PNOF induced a higher susceptibility to myocardial I-R injury in vivo at all ages in male mice, but only in young females. The mechanism of this sexual dimorphism in our model is not well understood, but could involve distinct levels of cardioprotective pathways expression, related to hormonal status.

Daily Rhythmic Expression Patterns of Melatonin Bio-synthesizing Genes in Zebrafish ( Danio rerio ) Testis in Response to Altered Feeding Condition

The alternation of light (L) and darkness (D) cycle is the most important zeitgeber (“time giver”) of the circadian system. Still, feeding time also acts as a potent synchronizer of the teleost circadian system. In fish, the impact of the altered photoperiodic condition is known, but the impact of altered feeding cycles in the daily rhythm of fish circadian system is largely unknown. The objective of this work was to explore how 12 hr shift in feeding time alters expression of genes concerned with melatonin synthesizing enzymes in zebrafish testis tissue. In this study, zebrafish maintained under a 12 hr light-12 hr darkness were fed at light phase (ZT03 and ZT10) in normal feeding (NF) group and another one was the altered feeding group (AF) fed at dark phase (ZT15 and 22) for 30 days. Daily rhythms of expression of genes concerned with melatonin synthesizing enzymes and circulating melatonin level were studied. The 12 hr shift in scheduled feeding induced a phase delay of 4-5 hr in the acrophases in the case of aanat2 , 10-11 hr for asmt and 4 hr for aanat1 but a slight shift seems to exist in case of tph1 . Serum melatonin levels showed a significant daily rhythm in both condition but displayed phase delay in AF condition. Rhythmic expression of aanat2 and peak at midnight corresponds with the high concentration of melatonin during the night. Melatonin is a multi-potent molecule; the change in the rhythmic expression of its bio-synthesizing enzyme genes through altered feeding time may lead to desynchronization in the physiology.

Creating a simple obesity working model of zebrafish

Background: Adult zebrafish (Danio rerio) and larvae forms are being used in studies related to obesity. According to the WHO, 13% of world population were obese in 2016 and between 1975 and 2016; the prevalence of obesity has been increased 3 times. Zebrafish has been a successful model for mammalian obesity to study various obesity-induced diseases in humans. Aims and Objectives: The objectives of the study are to create a zebrafish model of obesity and to study the effects of obesity on learning and memory using a visual discrimination test. Materials and Methods: Twenty zebrafish of 3–6 months of age were randomly selected and divided into two groups: (1) High feed group (HFG) (n = 10) and (2) normal feed group (NFG) (n = 10). The fishes were segregated into separate pots and numbered. Specified diet plan was followed for 8 weeks in both the groups. Length, weight, and body mass index (BMI) of fishes were measured every week and noted in Microsoft Excel sheet. Results: The HFG fishes were gaining more weight (P = 0.016) from the 5th week onward than the NFG fishes which were also evident with a significant difference in the BMI value from the 6th week (P = 0.011). However, the length did not have significant difference between the groups. Conclusion: The simple feed protocol which has been followed was successful in creating an obesity model of zebrafish. This zebrafish obesity model created can be further used for various research studies on obesity.

Sexual dimorphism in the long-term impact of postnatal nutritional programming on cardiac sensitivity to ischemia-reperfusion injury in vivo

Nutritional disturbances during the postnatal period may be responsible for a predisposition in adulthood to increased cardio-metabolic risk and a greater myocardial vulnerability to ischemia. However, these data have mainly been obtained in male mice, but less is known for females. The aim of our study was to evaluate the impact of postnatal overfeeding on cardiac sensitivity after in vivo ischemia-reperfusion (I-R) on both sexes. PNOF was induced by reduction of litter size of C57/BL6 mice immediately after birth: normally-fed group (NF) litters were composed of 9 pups/mother and overfed group litters (OF) of 3 pups/mother. The in vivo ischemia was induced by a 45 min ligation of the left anterior interventricular artery, followed by 24 hours of reperfusion, in hearts from 4 and 6 months aged male and female mice. The area at risk (AAR) was determined by Evans blue coloration and the infarct size by TTC staining. PNOF induced an early and permanent increase in body weight in OF group, for males (4 months: +13%; 6 months: +23%) and female mice (4 months: +23%; 6 months: +27%). A significant increase of infarct size was observed in hearts of overfed male mice aged of 4 and 6 months (respectively +37% and +32% of AAR), but it was just a trend for female mice at the same age. However, postoperative mortality was higher in both female groups (NF and OF) at 4 months (44%) and 6 months (37%) of age, as compared to males (4 months: 29%; 6 months: 18%). Nutritional programming through short-term PNOF induced a higher susceptibility to myocardial I-R injury in vivo, however with different intensities according to sex in mice. The mechanism of this different sexual dimorphism in our model is not well understood, but it could involve distinct levels of cardioprotective pathways expression.

Lipid Catabolism in Starved Yak Is Inhibited by Intravenous Infusion of β-Hydroxybutyrate.

Simple SummaryYak, which is the predominant and semi-domesticated livestock on the Qinghai-Tibet Plateau, suffers severe starvation and body weight reduction in the cold season because of the harsh highland environment. Lipids are important energy sources to starvation animals. β-hydroxybutyrate (BHBA) that is derived from lipid decomposition as the primary ketone body is with the function not only to provide energy for animals as energy materials, but also regulate lipid metabolism as signaling molecular. However, the effects of starvation and BHBA on lipid metabolism and its mechanism are still unclear for ruminant animals. Herein, we investigated the effects of starvation and intravenous infusion of BHBA solution on Yak growth, serum biochemistry, hormones, subcutaneous adipocyte morphology, fatty acid composition, activity of enzymes related to lipid metabolism, and signal pathway. The results showed that starvation promoted lipid catabolism and BHBA infusion up-regulated the mRNA expression of receptor GPR109A in subcutaneous adipose tissue, inhibited the Cyclic adenosine monophosphate(cAMP)/Protein kinase A (PKA)/cAMP-responsive element binding protein (CREB) signaling pathway, and inhibited lipolysis. Our study was beneficial for enriching the nutrition regulation theory of yaks and improving their growth potential.Lipid is the chief energy source for starved animals. β-hydroxybutyrate (BHBA) is the main ketone body produced by lipid decomposition. In Chinese hamster ovary (CHO) cell experiment, it was found that BHBA could be used not only as an energy substance, but also as a ligand of GPR109A for regulating lipid metabolism. However, whether BHBA can regulate lipid metabolism of yaks, and its effective concentration and signal pathway are not clear. This study investigated the effects and mechanism of starvation and BHBA on the lipid metabolism of yak. Eighteen male Jiulong yaks were selected and then randomly divided into three groups: normal feeding group (NG), starvation group (SG), and starvation with BHBA infusion group (SBG). The yaks in the NG group were freely fed during the trial, while the yaks in the SG and SBG groups fasted; from 7th to 9th days of the experiment, the NG and SG were infused continuous with 0.9% normal saline and SBG was infused 1.7 mmol/L BHBA solution respectively. The blood samples were collected on the 0th, 1st, 3rd, 5th, 7th, and 9th day of experiment. The subcutaneous adipose tissue of all the yaks in this study were taken from live bodies after infusion. Serum glucose, lipid metabolites, hormone concentrations, and mRNA and protein expressions of key factors of lipid metabolism and signaling pathway in subcutaneous adipose tissue were measured. The results showed that, as compared with NG, starvation significantly reduced the body weight of yak in SG, and significantly increased the concentration of BHBA in serum and the mRNA expression of PKA and CREB1 in subcutaneous adipose tissue, while the mRNA expression of MEK, PKC, ERK1/2, the area of adipocytes, and the proportion of saturated fatty acid were decreased. Whereas, further increase of BHBA concentration through infusion promoted the mRNA expression of GPR109A receptor in the subcutaneous adipose tissue of SBG, inhibited the mRNA expression of AC and PKA, and decreased the phosphorylation protein abundance of CREB1, and significantly increased the diameter and area of adipocytes. These findings suggest that starvation led to enhanced lipid catabolism in yaks. An increasing BHBA concentration could increase the mRNA expression of GPR109A receptor in subcutaneous adipose tissue and inhibit the cAMP/PKA/CREB signaling pathway and lipid decomposition.

Calorie Restriction in Adulthood Reduces Hepatic Disorders Induced by Transient Postnatal Overfeeding in Mice

Impaired early nutrition influences the risk of developing metabolic disorders in later life. We observed that transient postnatal overfeeding (OF) in mice induces long-term hepatic alterations, characterized by microsteatosis, fibrosis associated with oxidative stress (OS), and stress-induced premature senescence (SIPS). In this study, we investigated whether such changes can be reversed by moderate calorie restriction (CR). C57BL/6 male mice pups were maintained during lactation in litters adjusted to nine pups in the normal feeding (NF) group and three pups in the transient postnatal OF group. At six months of age, adult mice from the NF and OF groups were randomly assigned to an ad libitum diet or CR (daily energy supply reduced by 20%) for one month. In each group, at the age of seven months, analysis of liver structure, liver markers of OS (superoxide anion, antioxidant defenses), and SIPS (lipofuscin, p53, p21, p16, pRb/Rb, Acp53, sirtuin-1) were performed. CR in the OF group reduced microsteatosis, decreased levels of superoxide anion, and increased protein expression of catalase and superoxide dismutase. Moreover, CR decreased lipofuscin staining, p21, p53, Acp53, and p16 but increased pRb/Rb and sirtuin-1 protein expression. CR did not affect the NF group. These results suggest that CR reduces hepatic disorders induced by OF.

Effects of a Flavonoid-Rich Extract from Citrus sinensis Juice on a Diet-Induced Obese Zebrafish.

Background: Obesity is a pathological condition that has reached epidemic proportions; hence, it is necessary to find novel strategies aimed at fighting this disease. The present study was designed to evaluate the effect of a flavonoid-rich extract of orange (Citrus sinensis) juice (OJe) in diet-induced obese zebrafish. Methods: Adult zebrafish were divided into four diet groups: (i) normally fed (NF); (ii) overfed (OF); (iii) NF supplemented with OJe (5 mL/L in fish water; NF + OJe); and (iv) OF supplemented with OJe (OF + OJe). Each week, body weight (BW) and body mass index (BMI) were measured, and, at the end of the fifth week, euthanized zebrafish were processed for both microscopic evaluations and qPCR analyses. Results: In OF zebrafish, OJe significantly decreased both BW and BMI values and lowered the visceral adipose tissue, while it had little effect in the NF group. Moreover, it significantly reduced adipocyte cell size in both NF and OF groups in both visceral and subcutaneous adipose tissues, as well as their number in OF fish. Finally, OJe modulated some obesity-related genes, such as leptin A, ghrelin, orexin, pro-opiomelanocortin (POMC), and neuropeptide Y (NPY), in both gut and brain. Conclusion: This study adds new insights into the anti-obesity properties of orange juice and its flavonoids, suggesting their role as weight management agents through a lipolytic action linked to a restoration of metabolism-regulating gene expression.

P4613Long-term impact of postnatal nutritional programming on cardiac sensitivity to ischemia-reperfusion injury in vivo and on cardio-protective pathways in mice

Abstract Introduction Nutritional disturbances during the postnatal period may be responsible for a predisposition, or “programming”, to increased cardio-metabolic risk and to a progressive alteration of left ventricular contractility in adulthood. This nutritional perinatal programming may also lead to an alteration of cellular pathways involved in cardiac protection, such as the specific RISK and SAFE pathways, highlighted during pre- and post-ischemic conditioning or those of sirtuins (SIRT), histone deacetylases involved in the regulation of essential biological process. Purpose Our aim was to evaluate in mice the impact of postnatal overfeeding (PNOF) on cardiac sensitivity to ischemia-reperfusion (I-R) injury in vivo and on the myocardial expression of genes involved in heart protection against ischemia. Methods PNOF was induced by the reduction of litter size of C57/BL6 mice immediately after birth: normally-fed group (NF) was composed of 9 male pups/mother and overfed group (OF) of 3 pups/mother. In vivo ischemia-reperfusion injury was induced by the ligation of the anterior interventricular artery for 45 minutes followed by 24 h of reperfusion in hearts from 6-months aged mice. The gene expressions of proteins of interest composing the cardioprotective pathways (RISK pathway: Akt, ERK; SAFE pathway: JAK/STAT3; Sirtuins: SIRT1) were measured by RT-qPCR in mice aged 4 and 6 months. Results PNOF induced in OF group an early and permanent increase in body weight (+23%, p&lt;0.01, n=11) and a significant increase of infarct size (+32%, p&lt;0.05, n=11) at 6 months. Hearts OF mice aged 4 months showed a decreased expression of cardioprotective pathways, represented by a reduction in the gene expression of ERK1, Akt, PI3K, STAT3 and SIRT1. At 6 months, the expression of cardioprotective pathways was also reduced in OF group, with the diminution of the gene expression of STAT3, Akt and Erk1. Conclusion Nutritional programming through short-term PNOF induced a long-lasting decrease in the expression of signaling pathways involved in cardiac cellular protection, which could explain why 6-months old mice show increased susceptibility to myocardial I-R injury in vivo. The mechanism of these alterations needs further exploration, but could involve alterations in cardiomyocyte's balance between apoptotic and regenerative pathways, and epigenetic modifications. Acknowledgement/Funding French Fundation