Different sources of omega-3 polyunsaturated fatty acids affects apparent digestibility, tissue deposition, and tissue oxidative stability in growing female rats

Background Numerous health benefits associated with increased omega-3 polyunsaturated fatty acid (n-3 PUFA) consumption has lead to an increasing variety of available n-3 PUFA sources. However, sources differ in the type, amount, and structural form of the n-3 PUFAs. Therefore, the objective of this study was to determine the effect of different sources of ω-3 PUFAs on digestibility, tissue deposition, eicosanoid metabolism, and oxidative stability. Methods Female Sprague-Dawley rats (age 28 d) were randomly assigned (n = 10/group) to be fed a high fat 12% (wt) diet consisting of either corn oil (CO) or n-3 PUFA rich flaxseed (FO), krill (KO), menhaden (MO), salmon (SO) or tuna (TO) oil for 8 weeks. Rats were individually housed in metabolic cages to determine fatty acid digestibility. Diet and tissue fatty acid composition was analyzed by gas chromatography and lipid classes using thin layer chromatography. Eicosanoid metabolism was determined by measuring urinary metabolites of 2-series prostaglandins (PGs) and thromoboxanes (TXBs) using enzyme immunoassays. Oxidative stability was assessed by measuring thiobarbituric acid reactive substances (TBARS) and total antioxidant capacity (TAC) using colorimetric assays. Gene expression of antioxidant defense enzymes was determined by real time quantitative polymerase chain reaction (RT-qPCR). Results Rats fed KO had significantly lower DHA digestibility and brain DHA incorporation than SO and TO-fed rats. Of the n-3 PUFA sources, rats fed SO and TO had the highest n-3 PUFAs digestibility and in turn, tissue accretion. Higher tissue n-3 LC-PUFAs had no significant effect on 2-series PG and TXB metabolites. Despite higher tissue n-3 LC-PUFA deposition, there was no increase in oxidation susceptibility indicated by no significant increase in TBARS or decrease in TAC and gene expression of antioxidant defense enzymes, in SO or TO-fed rats. Conclusions On the basis that the optimal n-3 PUFA sources should provide high digestibility and efficient tissue incorporation with the least tissue lipid peroxidation, TO and SO appeared to be the most beneficial of the n-3 PUFAs sources evaluated in this study

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

\u3ci\u3eEts\u3c/i\u3e in the Kidney—Unraveling the Molecular Mechanism Underlying Renal Damage in Salt-Sensitive Hypertension

Originally identified as a homolog of a viral oncogene (v-ets), the ETS family of transcription factors consists of over 25 proteins involved in regulating several biologic processes at the transcriptional level. The ETS DNA binding domain consists of a winged helix conformation and binds the DNA sequences 5′-GGA(A/T)-3′ with varying affinity depending on ETS phosphorylation status, epigenetic modifications, and various protein-protein interactions

Recharacterizing the Murine Chronic Angiotensin II Infusion Model of Cardiovascular and Renal Injury

The chronic angiotensin II (AngII) infusion model is one of the most commonly used to study cardiovascular and kidney injury. However, the dosages of AngII used to induce cardiovascular or renal injury vary significantly in the literature. Therefore, we set out to determine the dosages of angiotensin II needed to produce renal injury and hypertension in mice. All experiments were performed in accordance with protocols approved by the Liberty University IACUC and conform to the FASEB standards for the use of animals in research and education. Male C57Bl/6J mice (~20 grams body weight) were purchased from The Jackson Laboratory and acclimated to our environment for one week. Mice were then assigned to receive 0, 400, 800, or 1200 ng AngII/kg BW*min for four weeks via osmotic minipumps (subcutaneous). Blood pressure (tail-cuff) was recorded each week of the study. At baseline, 2 and 4 weeks, renal blood flow and renal hemodynamics were estimated using contrast-enhanced ultrasonography. After 4 weeks, mice were placed in metabolic cages for the quantification of water intake and urinary output. Urine was stored for determination of albumin concentration using a commercially available ELISA. Mice were then euthanized and kidney tissues collected to measure the mRNA expression of several genes involved in the intrarenal renin-angiotensin system (RAS) (renin, angiotensinogen, angiotensin converting enzyme (ACE), ACE2, angiotensin II-receptor 1a (AT1a), and AT1b receptor) and tissue inflammation and remodeling [CCL5, α-smooth muscle actin (αSMA), collagen 1, collagen 3, and tumor growth factor β (TGFβ)]. All data were analyzed using general linear models in SPSS. Mice administered the 800 dose had the greatest and most consistent increase in systolic blood pressure (147 ± 8mmHg) as compared to mice administered the saline (114 ± 9, P=0.004) and the 400 dose (121 ± 11mmHg, P=0.01). Mice administered the 1200 dose tended (P=0.08) to have a greater total renal blood flow throughout the study, with a significant increase (P=0.047) in cortical blood flow as compared to mice administered saline. Despite the modest changes in estimated renal blood flow, mice administered the 800 and 1200 doses of AngII had similar, yet significantly greater (P≤0.001) water intake and urinary output as compared to mice treated with saline or the 400 dose. Similarly, mice with the 800 and 1200 doses had significantly greater evidence of tissue damage evident by increased albuminuria (P≤0.05) and increased renal gene expression of CCL5, TGFβ, collagen 1, and collagen 3. There was also an effect on the intrarenal RAS, with mice administered the 800 and 1200 doses having significant (

Determining the Physiological Interaction Between Diet and Alcohol Intake in Male Mice

Poor nutrition and alcohol intake are leading environmental factors associated with morbidity and mortality worldwide. However, the physiological interactions between poor diet and excessive alcohol intake remain unclear. Prior research from our lab showed diet significantly influenced measures of kidney and liver function in mice exposed to alcohol for 3 weeks. However, it was unclear whether the effects were due to diet, chronic alcohol consumption, or an additive effect of both. All experiments were performed in accordance with protocols approved by the Liberty University IACUC and conform to the FASEB standards for the use of animals in research and education. Weanling (3-week old) male mice from the C57Bl/6 strain were purchased from The Jackson Laboratory and acclimated to a standard chow diet and housing for 7 days. Mice were then given ad libitum access to 1 of 3 diets: 1) standard laboratory chow, 2) a commercially available Western Diet (WD), or 3) a novel Americanized diet (AD). The AD was formulated to match the 50th percentile of intake for sodium, potassium, simple sugars, phosphorus, and fiber as reported in the recent What we eat in America report, based on 2011–2012 NHANES data. After 6 weeks on their assigned diet, each dietary group received distilled water or 10% (volume) ethanol solution as their only source of drinking water for an additional 4 weeks. Body weights and beverage consumption were recorded each week throughout the study. Systolic blood pressure was recorded at baseline and after 4 weeks of ethanol exposure. Following 4 weeks of ethanol intake, renal blood flow was estimated using contrast-enhanced ultrasonography, and the mice were euthanized and kidney and liver tissues were processed for histology and quantitative real-time RT-PCR analysis of gene expression. All data were analyzed using general linear models in SPSS. Diet significantly influenced body weight, with both the WD and AD fed mice having a similarly (p=0.1) greater body weight as compared to mice fed chow (p\u3c0.01). However, alcohol had no additional effect on weight gain (p=0.1). Consistent with previous findings, mice fed chow had the highest daily consumption of alcohol that was greater (p=0.05) than mice fed the WD, but not mice fed the AD (p=0.8). Histological analysis revealed hepatic steatosis in mice fed the WD and AD, and this did not appear to be worsened by alcohol intake. Although there was no difference in systolic blood pressure between the groups, mice fed the AD had a significant reduction in estimated renal blood flow as compared to mice fed WD (p=0.01) and chow (p\u3c0.001). Interestingly, ethanol consumption caused a 25% increase in estimated renal medullary flow. Preliminary data indicate that genes (Hspa5 and Hsp90b1) associated with the cellular response to stress in the endoplasmic reticulum (ER) were expressed at higher levels in livers of mice fed the WD and AD, and this apparent ER stress was not exacerbated by alcohol intake. Taken together, the results from this study suggest that diet and alcohol significantly influence liver and renal health in mice, with a majority of the pathophysiology caused by diet

Determining the Influence of a Novel Rodent Diet on Body Weight Gain and Renal Health in Male Mice from 2 Different Strains

Diet has an established relationship with health in humans; yet it is poorly represented or significantly oversimplified in most preclinical animal studies. Based on recent data, the “typical” American adult consumes a diet that is inadequate in several nutrients and high in salt and energy yielding compounds (particularly simple sugars). However, rodents diets used to model the nutritional composition of developed (or “Western”) societies do not embody these same inadequacies. Interestingly, many of the nutritional inadequacies noted in developed countries have been independently shown to negatively affect renal health in animal models. However, to our knowledge no animal studies have adequately determined the physiological consequences of consuming a diet modeling the complex nutritional inadequacies of Americans. Based on this information, we hypothesized that mice consuming an “Americanized diet” (AD) would have greater weight gain and evidence of renal injury as compared to mice fed chow. All animal experiments were performed following animal protocols approved by the Liberty University IACUC and conform to the FASEB Statement of Principles for the use of animals in research and education. Weanling (3-week old) male 129 Svlm/J (129, n=10) and C57Bl/6J mice (B6, n=10) were obtained from Jackson Laboratory and given 1 week to acclimate to solid diet. Mice were then assigned (n=5 per strain) to remain on a commercially available chow diet or our novel AD formulated to have similar nutritional inadequacies as reported by recent NHANES anlyses. Mice were given ad libitum access to their respective diets for 6 weeks and 24-hour dietary intake and body weights were recorded throughout the study. At the end of the 6-week feeding study, mice were individually housed in metabolic cages to collect urine for determination of albuminuria by ELISA. Renal blood flow was estimated using contrast-enhanced ultrasonography. All statistical analyses were performed using general linear models in SPSS. The B6 mice had higher average 24-hour caloric intake and resulted in a significant increase in body weight in the B6 mice (P=0.01), with the B6 mice consuming the AD having the highest food intake and overall body weight. Strain and diet both significantly influenced urinary output regardless of water intake (covariate), with higher (P=0.03) urinary output in the 129 strain (0.9±0.1 vs 0.4± 0.1 mL urine/day, 129 and C57Bl/6 respectively) and in mice consuming the AD diet (0.8±0.1 vs 0.5±1 mL urine/day). Regardless of strain, all mice consuming the AD tended (P=0.06) to have a greater 24 hour albumin excretion (26.7±4 μg) as compared to mice consuming chow (14.7±4 μg). Strain also significantly influenced estimated renal blood flow regardless of diet, with the B6 mice having a greater (P=0.02) estimated renal blood flow as compared to the 129 strain. Taken together, our data strongly suggest that a rodent diet formulated to match the nutritional quality of a “typical” American significantly influences renal health, particularly albuminuria and daily urinary volume. These data also highlight a strain difference in regards to renal outcomes alone or in combination with diet. Further studies are needed to elucidate the physiological mechanisms dictating these differences and provide insight into the nutrients involved in initiating renal dysfunction

Neutrophil Depletion Influences Renal Outcomes in Male Mice with Chronic Angiotensin II Infusion

Hypertension is the leading cause of morbidity and mortality worldwide; yet the exact cause for many cases remain unknown. Recent research has highlighted the significance of the immune system in the development and progression of HTN in animal models. Much of this research has focused on classical immune pathways involving antigen presenting cells and subsequent activation of the adaptive immune response (primarily CD8+ T-cells). These activated lymphocytes then support the development of HTN by mediating end-organ damage in organs tasked with regulating blood pressure and extracellular volume (such as the kidneys). In the current study, we set out to determine the role of neutrophils in a murine model of HTN – the chronic angiotensin II (AngII) infusion model. All animal experiments were performed following animal protocols approved by the Liberty University IACUC and conform to the FASEB Statement of Principles for the use of animals in research and education. Baseline blood pressure was recorded in male C57Bl/6 mice (N=10) for 3 weeks using the CODA-8 tail cuff volume pressure recording system. Neutrophil depletion was accomplished via intraperitoneal injections of a monoclonal anti-Ly6G antibody (1A8, n=5), or IgG control (2A3, n=5) every 48 hours (250μg/mouse). 18 hours following the first antibody injection, a mini-osmotic pump was implanted into the rear flank delivering 500ng/kg*min AngII. 3 days after pump implantation, blood pressure readings resumed and continued for 14 days. After 14 days, mice were individually housed in metabolic cages and urine was collected for quantification of albuminuria. Renal blood flow was estimated in anesthetized mice using contrast-enhanced ultrasonography. Following renal blood flow estimation, mice were euthanized and blood, kidney, and spleens collected for determination of leukocyte content by flow cytometry. All data were analyzed using general linear models procedures in SPSS. Significant differences in blood pressure were observed periodically during the 14 days of AngII infusion (P≤0.05 for days 8, 12, and 14); however, the overall effect of treatment (1A8 vs. 2A3) did not reach statistical significance (P\u3c0.2). Mice receiving the 1A8 neutrophil depleting antibody also tended (P≤0.07) to have a higher urinary output and albuminuria as compared to mice receiving the isotype control (respectively). No difference in estimated renal blood flow was detected between the treatment groups. Tissue analysis by flow cytometry confirmed the depletion and/or significant reduction of circulating and splenic neutrophils in mice receiving 1A8, but not 2A3, injections after 2 weeks. In the kidneys, mice receiving the 1A8 neutrophil depleting antibody had reduced (P=0.03) CD45+ leukocyte content. Further analysis of renal single cell suspensions revealed a significant reduction (P=0.04) in B-cells and higher (P=0.03) CD8+ T-cells in 1A8 treated animals. Taken together, our data suggest that neutrophil depletion alters several renal outcomes in the AngII murine model of HTN, with neutropenic mice tending to have higher blood pressure, greater urinary output and albuminuria as compared to control mice. These effects could be mediated by the significant differences in renal leukocyte content between the treatment groups. Further studies are needed to confirm our results and delineate the molecular mechanisms responsible for altered renal function and inflammation due neutrophil depletion in this animal model

A comprehensive analysis of the composition, health benefits, and safety of apple pomace

Apple processing results in peel, stem, seeds, and pulp being left as a waste product known as apple pomace. This review comprehensively assessed apple pomace composition for nutritional value and bioactive substances and evaluated potential health benefits and safety. Apple pomace is a rich source of health-benefitting nutrients, including minerals, dietary fiber, antioxidants, and ursolic acid, which suggests it has potential use as a dietary supplement, functional food, and/or food additive. Preclinical studies have found apple pomace and its isolated extracts improved lipid metabolism, antioxidant status, and gastrointestinal function and had a positive effect on metabolic disorders (eg, hyperglycemia, insulin resistance, etc.). Safety studies have shown apple pomace to be a safe livestock feed additive and to have pesticide concentrations within safety thresholds established for human consumption. Commercial development of apple pomace for human consumption requires more research focusing on standardized methods of nutrient reporting, mechanistic studies, and human clinical trials

A comprehensive analysis of the composition, health benefits, and safety of apple pomace

Apple processing results in peel, stem, seeds, and pulp being left as a waste product known as apple pomace. This review comprehensively assessed apple pomace composition for nutritional value and bioactive substances and evaluated potential health benefits and safety. Apple pomace is a rich source of health-benefitting nutrients, including minerals, dietary fiber, antioxidants, and ursolic acid, which suggests it has potential use as a dietary supplement, functional food, and/or food additive. Preclinical studies have found apple pomace and its isolated extracts improved lipid metabolism, antioxidant status, and gastrointestinal function and had a positive effect on metabolic disorders (eg, hyperglycemia, insulin resistance, etc.). Safety studies have shown apple pomace to be a safe livestock feed additive and to have pesticide concentrations within safety thresholds established for human consumption. Commercial development of apple pomace for human consumption requires more research focusing on standardized methods of nutrient reporting, mechanistic studies, and human clinical trials