bluuebunny/crossref_metadata_2025 huggingface dataset:
Kisspeptin signaling in oocytes is compulsory for ovulation in adult mice
Authors: Ruohonen Suvi T , Gaytan Francisco , Gaudi Andrea Usseglio , Franssen Delphine , Ohlsson Claes , Poutanen Matti , Tena‐Sempere Manuel
Published: June 2021

Kisspeptins, encoded by the Kiss1 gene, are crucial brain factors for the control of reproduction, with an essential role in the generation of the pre‐ovulatory surge of gonadotropins and, hence, ovulation. Yet, kisspeptins are also found in peripheral reproductive organs and their receptor, Gpr54, is expressed in various target tissues, including the ovary, where its physiological role remains contentious. Global Gpr54−/− mice are hypogonadotropic and infertile; female null mice display disrupted folliculogenesis and anovulation. However, despite the predominant brain actions of kisspeptins, how much of this phenotype is due to local, and not central, kisspeptin signaling deficiency remains unknown. To address this, we generated a conditional oocyte‐specific Gpr54 deficient mouse line (OoGpr54−/−), by crossing Gdf9‐Cre+ mice with Gpr54loxP/loxP mice. The efficacy of Gdf9‐promoter to drive the expression of Cre in oocytes was verified by a breeding test, and the Gpr54 depletion from oocytes was confirmed with RT‐qPCR. At the time of pubertal transition, OoGpr54−/− females were indistinguishable from their wiltype controls with preserved puberty onset. However, already at 2 months of age, 45% of OoGpr54−/− females showed histological features reminiscent of ovarian failure, with presence of large atretic antral follicles and absence of corpora lutea as an index of anovulation. These features were also associated with disrupted estrous cyclicity characterized by an increase in the length of the estrus phase of the uterine cycle. Penetrance of this phenotype progressed with age, with 55% of OoGpr54−/− females at 3–4 months, 80% at 6 months and 100% at 10 months displaying features of complete premature ovarian insufficiency (POI). In addition, 4‐month‐old OoGpr54−/− female mice displaying POI showed decreased serum estradiol and progesterone levels, yet sustained Gpr54 expression in the hypothalamus and unaltered basal gonadotropin levels. Ovarian RNASeq analyses revealed global changes in expression profiles in OoGpr54−/− mice, including genes involved in cellular communication, steroidogenesis and intracellular signaling pathways. Finally, the anovulatory state of OoGpr54−/− mice was rescued by exogenously administered gonadotropin priming, and was largely prevented by early onset consecutive pregnancies, although multiparous OoGpr54−/− dams showed a slight decrease in fecundity. Our results pinpoint the important role of oocyte kisspeptin signaling in the direct control of ovulation, whose deregulation may also be an underlying cause for POI in women.

Support or Funding Information

FiDiPro programme of Academy of Finland and Sigrid Juselius foundation

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effect of Exercise or Meditation on Reported Stress and Cortisol in an Undergraduate Population
Authors: Clarke Alicia M , Cohen Brian D
Published: June 2021

Stress is a daily factor that is directly correlated with negative physiological and psychological effects including stroke, heart attacks and problem drinking. A stressor that is perceived by the body activates the hypothalamic‐pituitary‐adrenal (HPA) axis which causes the synthesis and release of the glucocorticoid hormone cortisol from the adrenal cortex. Studies have shown meditation or exercise programs help decrease stress and cortisol levels but this has not been tested in college‐aged adults. In this study, undergraduate students were assigned to either meditation, exercise or control groups for four weeks to measure the effects of introducing either meditation or increased exercise on reported stress and physiological response to stress in the form of salivary cortisol levels. Participants' stress was measured using the Revised Undergraduate Student Hassles Scale (RUSH‐S) which measures a variety of stressors including academic, social, and personal hassles. Students completed the RUSH‐S 3 times: at baseline and at 2 week intervals. Simultaneously, saliva samples were collected to analyze salivary cortisol levels using an enzyme‐linked immunosorbent assay (ELISA). A one‐way between subjects ANOVA was conducted to compare the effect of interventions on personal, academic and social stressors as measured by the RUSH‐S. Both personal and social stressors were reduced for the meditation and exercise groups compared to the control group (p=0.037 and p=0.052, respectively). No significant reduction of academic stress was observed in either group compared to the control. Cortisol levels tended to correlate with RUSH‐S results. This study suggests that interventions such as meditation or exercise may be beneficial to reducing stress in undergraduate populations.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Immunological Response to Chronic Stress in Obese Mice
Authors: Parsley Matthew , Burrage Emily , Marshall Kent D , Clemons Garrett D , Tice Abigail , Bryner Randy W , Brundage Kathleen , Kelley Eric E , Chantler Paul D
Published: June 2021

Chronic stress is a major risk factor for cardiovascular disease. We have shown that chronic stress, which acts as a trigger for anxiety and depression, significantly reduces vascular function in obese rats and mice. Such vascular dysfunction is linked to an increase in systemic inflammation. The spleen and adipose tissue are major sources of these peripheral immune cells. We sought to identify the immunological changes in the spleen after chronic unpredictable stress (UCMS).

Spleen and gonadal adipose tissue immune cells from male obese mice who underwent either 8 weeks of non‐UCMS (controls, n=6) or UCMS (n=6) for 5 days/week/7Hrs/day to elicit a depressive phenotype were analyzed by flow cytometry.

Spleen size was 23% lower (p=0.08) in the UCMS group vs. controls, yet the body weight for the UCMS mice was reduced compared to obese controls (48±0.7 vs. 42±0.8, p<0.01), resulting in no differences in the ratio of spleen/body weight. To evaluate and quantify changes in the cellular immune composition of the spleen with UCMS, we harvested spleens from control and UCMS obese mice. UCMS mice tended to have lower numbers of CD45 compared to controls. Although no differences in CD8, CD4 or the CD4/CD8 ratio, or B‐cells were noted, the number of M2 macrophages were generally lower in the UCMS vs. control group, with no differences in M1 macrophages. In the visceral adipose tissue, CD45+ cells were lower in the UCMS group, which was accompanied by a lower number of CD8+ and CD4+ cells in the UCMS groups.

Our data suggests that chronic stress in obese mice alters the immune cell populations in the spleen and visceral fat of obese mice. Given that these tissues play an important role in the release of immune cells into the systemic circulation, the immune changes could play an important role on the vascular dysfunction noted in our mice with exposure to chronic stress.

Support or Funding Information

OD016165 (KB)

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Hepatic Knockdown of RECK Increases NASH Susceptibility
Authors: Cunningham Rory P. , Moore Mary P. , Nguyen Nhu , Dashek Ryan , Boccardi Luigi , Jepkemoi Vivien , Meers Grace M. , Chandrasekar Bysani , Rector R. Scott
Published: June 2021

Introduction

Nonalcoholic steatohepatitis (NASH) is characterized by hepatic steatosis, hepatocellular inflammation and fibrosis. Reversion‐inducing‐cysteine‐rich protein with Kazal motifs (RECK) exerts anti‐fibrotic effects in the heart, although its role in NASH is unknown. We have previously shown that western diet (WD)‐induced NASH and fibrosis were associated with RECK downregulation in the liver. Here, we examined whether RECK knockdown, specifically in liver, increases NASH susceptibility.

Methods

Homozygous RECK floxed mice on a C57/BL6J background were injected with either an AAV8‐TBG‐Cre (1×1012) (RECK‐KD) for liver‐specific knockdown of RECK or an AAV8‐TBG‐GFP control (RECK‐CON). Following AAV injections, mice (n = 5–8) were fed either a control diet (CD; 10% fat) or WD (45% fat, 17% sucrose) for 8 weeks. An additional set of mice injected with AAV8‐TBG‐Cre or AAV8‐TBG‐GFP were fed WD for 30 weeks (n = 8).

Results

After 8 weeks, WD feeding significantly increased body weight and body fat percentage vs CD (p≤0.05). There were no differences in animal characteristics between RECK‐KD and RECK‐CON in either CD or WD groups. Nonalcoholic fatty liver disease activity score (NAS; combination of steatosis, ballooning, and inflammation) was significantly elevated in WD vs CD fed mice (p<0.05), with further exacerbation with RECK‐KD for NAS and inflammation scores (main effect for genotype, p<0.05). Furthermore, RECK‐KD mice had a ~3‐fold increase in hepatic fibrosis compared to RECK‐CON (main effect for genotype, p≤0.05). Thirty weeks of WD feeding significantly elevated NAS (p<0.01) and fibrosis scores (P<0.01) compared with 8 weeks of WD feeding. In addition, RECK knockdown exacerbated NAS (p<0.05), inflammation score (p=0.001), and fibrosis (p=0.06) compared to RECK‐CON mice following 30 weeks of WD feeding. Further investigations revealed that RECK‐KD (vs. RECK‐CON) expressed significantly higher IKK‐β gene expression (p<0.05), along with trends for increases in hepatic inflammatory markers NF‐κB, TGF‐β, and JUN at 30 weeks. Expression of matrix metalloproteases‐2 and −14 also tended to be elevated in RECK‐KD mice (vs RECK‐CON) at 30 weeks.

Conclusion

Here we demonstrate for the first time that liver‐specific RECK knockdown exacerbates western diet induced NASH. Further investigation is warranted to determine the role and precise mechanisms by which RECK regulates hepatocellular inflammation and NASH progression.

Support or Funding Information

VA Merit Grant I01BX003271‐01 (R.S.R.), VA Merit Grant I01BX004220‐01 (B.C.)

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Systemic Exposure of Orally Ingested Fructose is Similar between Fructose‐tolerant and Fructose‐intolerant Functional Gastrointestinal Disorder (FGID) Patients
Authors: Lee Sze Han , Low Jing Yi , Kioh Dorinda Yan Qin , Wilder‐Smith Clive , Chan Eric Chun Yong
Published: June 2021

Background

Dietary intolerance to fructose is common (60%) in Functional Gastrointestinal Disorder (FGID) patients, yet poorly characterized and empirically managed. Fructose is postulated to be malabsorbed in fructose‐intolerant FGID patients, resulting in gastrointestinal symptoms when unabsorbed fructose is fermented by gut microbiota to form gases. Malabsorption can be indirectly characterized by gas breath tests (i.e. methane, hydrogen) and measurement of systemically absorbed fructose and its metabolites. However, both methods are typically done independently, and the mechanism leading to fructose intolerance remains poorly understood.

Objective

We aim to correlate plasma fructose and its metabolites in FGID patients after fructose ingestion in their relation to fructose intolerance.

Methods

Thirty‐one FGID patients, as defined by Rome III criteria, were enrolled into a randomised crossover study in Switzerland (1). Blood (plasma) were collected at 0, 0.5, 1 and 2 h post‐ingestion of 35g fructose or water. Plasma fructose and its metabolites (glucose, alanine, lactate, glycerate) were quantified via liquid chromatography tandem mass spectrometry. Symptoms were recorded using standardized questionnaires, while breath concentrations of hydrogen and methane were measured via BreathTracker Analyzer.

Results

Intolerance symptoms correlated positively with hydrogen (r=0.7175) and methane (r=0.6093) breath test over the 2 h period, with fructose‐intolerant patients producing significantly more hydrogen (p = 0.0406) and methane (p=0.0400) than fructose‐tolerant patients. However, intolerance symptoms correlated poorly with systemic exposure (AUC0–2h) of fructose (r=−0.0066). AUC0–2h of fructose and its metabolites (glucose, alanine, lactate, glycerate) were similar between fructose‐tolerant and fructose‐intolerant phenotypes.

Conclusion

For the first time, our study demonstrated fructose intolerance and its higher levels of gases are not associated with fructose malabsorption. Our findings alluded to the potential role of modulated gut microbiota activity in characterizing the differential fructose fermentation phenotypes.

Support or Funding Information

Funded by Brain‐Gut Research Group, Bern, Switzerland

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effects of Obesity and Exercise on Pancreatic Oxidative Stress, Morphology, and Health
Authors: Tice Abigail , Branyan Kayla W , DeVallance Evan R , Marshall Kent L , Kelley Eric , Olfert Mark , Chantler Paul D , Bryner Randy
Published: June 2021

Obesity is concomitant with hyperglycemic conditions and increased oxidative stress. Under hyperglycemia, thioredoxin interacting protein (TXNIP) causes increased oxidative stress and β‐cell apoptosis within the pancreas.

Lean rats (LZR) and obese rats (OZR) were randomly assigned to control (n=12) and exercise (n=12) groups. Exercise LZR (n=6) and OZR (n=6) underwent 8 weeks of multi‐lane motor treadmill running for 60 minutes at 60–70% maximum determined intensity. Pancreas tissue was harvested at approximately 20 weeks and mounted on cork using OTC freezing medium.

Pancreas sections of 8μm thickness were cut and collected on slides then stained using DAPI and Alexa‐Fluor 546 targeting primary insulin antibodies. Slides were then imaged using the Zeiss LSM 510 Confocal microscope and Zeiss computer software; islet area and β‐cell number were determined. Nitrate analysis was measured using the Sievers Nitric Oxide Analyzer (NOA 280) using pancreas lysates. The WES system was used for Western analysis of TXNIP protein quantification.

Body mass, glucose and insulin were significantly greater in OZR vs LZR (p<0.05). OZR also had higher beta‐cell numbers and islet areas to LZR (Table 1), although not significant. There was an almost 3‐fold increase in TXNIP in OZR compared to LZR (p=0.03). OZR that exercised experienced an approximate 2‐fold decrease in TXNIP expression when compared to the OZR control (p=0.02). No difference was observed between OZR exercised and LZR control (p=0.18).

This study showed an increase in the expression of TXNIP in the pancreas of obese compared to lean groups. Eight weeks of treadmill running was associated with decreasing the expression of TXNIP in OZR to almost the same level as the LZR controls, suggesting that exercise may be used as a means to reduce oxidative stress even in a hyperglycemic obese environment.

Current studies are being conducted to further assess markers of oxidative stress and nitric oxide associated with these perturbations, as well as pro‐apoptotic markers within the pancreas.

Support or Funding Information

NIHGMS 5U54GM104942‐03 (PDC)

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Alterations to the Gut Microbiome Prevent Glucocorticoid induced Osteoporosis
Authors: Schepper Jonathan , Rios‐Acre Naiomy , Collins Fraser , Parameswaran Narayanan , McCabe Laura
Published: June 2021

Glucocorticoids are important anti‐inflammatory drugs that can have significant side effects including glucocorticoid‐induced osteoporosis (GIO). Glucocorticoids directly induce apoptosis of osteoblasts and osteocytes but have also been shown to alter the gut microbiota composition. Previously, our lab and others have shown that the microbiota is involved in the regulation of bone density, however, little is known about the role of the gut in regulating GIO. Therefore, we investigated the role of microbiota alterations in GIO. Male C57BL/6J (16‐weeks‐old) mice received 8‐weeks of glucocorticoid treatment (GC, 2.5 mg/kg/day, slow release pellet subQ) with or without chronic antibiotic treatment (ABX, ampicillin and neomycin) to deplete the microbiota. Strikingly, the ABX‐GC mice did not lose bone, whereas the non‐ABX GC mice lost 40% trabecular bone volume. Based on this previously unknown link between microbiota and GIO, we examined if GIO can be prevented by using probiotics to modify the microbiota of the GC mice. Male mice were GC treated with or without oral Lactobacillus reuteri (LR; 108 cfu/day) supplementation. After 8 weeks, analyses of stool and colon samples revealed that LR treatment significantly alters the microbiota composition compared to GC treated mice. More importantly, LR treatment prevented GIO. Analyses of intestinal permeability established that GC treatment increases intestinal permeability, an outcome that was prevented by treatment with chronic ABX and LR. To determine if intestinal barrier function was mechanistically important for GIO, we treated GC‐mice with a mucus supplement (MDY). Strikingly, enhancement of barrier function prevented both GC‐induced barrier dysfunction and GIO. Together these data highlight the unappreciated role of the gut microbiota in GIO pathogenesis, and identify novel therapeutic targets for preventing GIO.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Consequences on Gametogenesis and Reproduction Performances of a High Carbohydrate Nutrition During the Whole Reproductive Cycle of Male and Female Trout
Authors: Marandel Lucie , Hu Huihua , Liu Jingwei , Mennigen Jan , Bobe Julien , Corraze Geneviève , Burel Christine , Panserat Stéphane
Published: June 2021

Salmonids and more particularly rainbow trout are carnivorous species, and thus usually consider as glucose‐intolerant (GI) species and poor user of dietary carbohydrates displaying a decrease in growth and a persistent postprandial hyperglycaemia when fish meal is substituted at more than 20% by digestible carbohydrates in the diet. Nevertheless, these findings were mainly deduced from experiments conducted on immature juvenile trout and only scarce data are available in sexually mature males and females. In this regard, we investigated the impact of a high carbohydrate diet (HC diet) on gametogenesis and reproductive performances of 2 year‐old broodstocks fed with such a diet a whole year. Our results showed that both males and females ate and growth well when fed the HC diet even if, at the end of the trial, males, but not females, displayed growth retardation compared to control males. The glycaemia of fish fed the HC diet was higher than fish fed the control diet independently of the sex but these fish were not hyperglycaemic. Surprisingly, both sex displayed a precocious maturation. Whole body and gonads biochemical composition of fish did not differ during the whole year from one treatment to the other whereas liver of fish fed the HC diet retained more glycogen but less proteins compared to the control fish. We also monitored glucose metabolism modifications at the molecular level in both livers and gonads at different gametogenesis time points. Our results demonstrated that glucose metabolism strongly varied in female liver during gametogenesis independently of the diet whereas in male no significant difference where found. By contrast in both ovaries and testis, glucose metabolism related genes were found differentially expressed during gametogenesis but independently again of the diet. At spawning period, we performed cross‐fertilization between groups. For the 4 groups, both fertilization and early developmental rate were equivalent from one group to the other. In overall, our results highlight strong but sex‐dependent effects of a high carbohydrate diet on both oogenesis and spermatogenesis and a variation of glucose metabolism in both liver and gonads. However, these effects do not seem to affect reproductive performances.

Support or Funding Information

This study was supported by the French National Research Agency (ANR‐18‐CE20‐0012‐01 ‘SweetSex’).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Metabolic Consequences of Exposure to Maternal High Fat Diet in Offspring
Authors: Thakali Keshari M , Piccolo Brian D , Sikes James D , Wahl Elizabeth C , Shankar Kartik
Published: June 2021

The increased risk for obesity in offspring born to obese mothers may be driven by changes in energy expenditure. To examine the effects of maternal high fat diet (HFD)‐induced obesity on offspring energy expenditure, female C57BL6/J mice were fed a control (17% fat, TD95092) or HFD (45% fat, TD8811) ad libitum for 12 weeks prior to and during pregnancy and during lactation. Female mice were bred with lean male mice at 17 wk of age. At weaning, male offspring from control and HFD‐dams were randomized to control (C) or HFD (H), provided ad libitum, generating 4 groups of offspring: CC, CH, HC, and HH, where the first letter corresponds to maternal diet and the second to offspring post‐weaning diet. At 20 weeks of age, energy intake and expenditure (EE) were assessed in male offspring over 48 h using the Promethion Continuous Indirect Calorimetry system (Sable Systems). HFD consumption in offspring was associated with reduced respiratory exchange ratio (RER, CC vs CH: 0.89±0.02 vs 0.82±0.02; p<0.01, n=13–16). There was no effect of maternal HFD on offspring RER (CC vs HC, p= 0.66; CH vs HH, p=0.54). To examine the effect of maternal HFD on offspring energy expenditure, ANCOVA using offspring total body weight (measured at the beginning of the indirect calorimety experiment) as a covariate for the 48 h recording period (both light and dark cycles) was performed. When comparing the effect of maternal HFD in offspring fed either a control diet (CC vs HC) or HFD (HC vs HH) postweaning, the covariate (offspring total body weight) significantly predicted EE for both comparisons (CC vs HC, p<0.05; HC vs HH, p = 0.05), while there was no significant effect of maternal diet on EE. Offspring food intake (in both light and dark cycles) was not altered by maternal HFD (CC vs HC, p=0.22; CH vs HH, p=0.21). In control‐fed offspring, maternal HFD had no effect on body weight at 20 wk of age (CC vs CH, 26.84±0.79g vs 28.91±1.03g, p=0.12), while in HFD‐fed offspring, males exposed to maternal HFD were significantly heavier than males from control‐fed dams (CH vs HH, 33.81±1.46g vs 38.42±1.59g, p=0.04). The observed changes in RER indicate that offspring post‐weaning HFD, but not maternal HFD, is associated with a shift in substrate utilization, specifically with increased fat oxidation in response to post‐weaning HFD. In the context of maternal HFD, the EE data suggest that offspring total body weight, and not maternal obesity may be driving offspring changes in energy expenditure.

Support or Funding Information

USDA ARIS Project 6026‐51000‐010‐05S

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Sex‐dependent protection from high fat diet‐induced metabolic disease in mice lackingDegenerin proteins
Authors: Drummond Heather , Mitchell Zachary , Hildebrandt Emily , Stec David E
Published: June 2021

Degenerin proteins, such as βENaC and ASIC2, and Transient Receptor Potential Channel 6 (TrpC6) have been implicated in cardiovascular function. However, their roles and potential interaction in metabolic disease has not been studied. To begin to assess this interaction, we evaluated the impact of a high fat diet (HFD) on in mice lacking normal levels of ASIC2, βENaC and TrpC6. Twenty week old male and female mice were placed on a 60% HFD for 12 weeks. Body weight was measured weekly, body composition by non‐invasive ECHO MRI and fasting blood glucose were measured at 0, 4, 8 and 12 weeks. A glucose tolerance test was administered after 12 weeks. Differences between ASIC2/βENaC/TrpC6 and WT groups were compared using independent t‐tests within each sex. Data are presented as mean ± SEM, ASIC2/βENaC/TrpC6 vs. WT. At 20 weeks of age, female ASIC2/βENaC/TrpC6 mice (n=6) weighed less (22.7±1.0 vs 26.3±0.8g, p=0.029) and gained less weight (12.1±1.7 vs. 20.5±1.3g, p=0.004) than WT (n=5). Total body fat (16.2±2.0 vs 23.2±1.1g, p=0.017) and lean body masses (19.2±1.0 vs 24.8±0.7, p=0.0014) were reduced in female ASIC2/βENaC/TrpC6 mice. In contrast, male ASIC2/βENaC/TrpC6 (n=5) mice had similar body weight (34.1±0.8 vs. 36.8±1.8g, p=0.165) at 20 weeks and 12 week HFD weight gain (11.8±1.5 vs. 12.1±0.9g, p=0.881) compared to WT (n=4). Fasting blood glucoses were lower in female (166±6.4 vs.212±5.3 mg/dL, p=0.0004) and male (181±2.8 vs.210±9 mg/dL, p=0.006) ASIC2/βENaC/TrpC6 mice after 12 weeks HFD. The area under the curve for the glucose tolerance test was reduced in female (18263 ± 510 vs 34623±4719 min.mg/dL), but increased in male (26100±1639 vs. 19408±1364 min.mg/dL) ASIC2/βENaC/TrpC6 mice. Liver (0.83±0.05 vs. 1.93±0.34g, p=0.0066) and liver fat (0.011±0.007 vs.0.333±.158, p=0.05) masses, as well as percent liver fat (1.1±0.6 vs. 14.4±4.1%, p=0.006), were reduced in female ASIC2/βENaC/TrpC6 mice after HFD. While liver (1.77±0.13 vs. 2.49±0.15g, p=0.007) and liver fat (0.17±.06 vs. 0.37±.03g, p=0.044) masses were reduced in male ASIC2/βENaC/TrpC6 mice, percent liver fat was not statistically lower (8.8±2.6 vs. 14.7±0.7%, p=0.11). These highly novel findings suggest that ASIC2, βENaC and/or their interaction with TrpC6, protects against HFD induced‐metabolic disease in female, but not male, mice. The mechanisms underlying this response will be examined in future studies.

Support or Funding Information

This work was support by NIH P01HL051971, P20GM104357, P20GM121334 and R01HL136684.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
High‐tryptophan Diet Reduces Weight Gain in Rats via Indole‐3‐propionic Acid, a Gut Microbiota Metabolite
Authors: Konopelski Piotr , Konop Marek , Gawrys Marta , Piotr Podsadni , Ufnal Marcin
Published: June 2021

Tryptophan is an essential amino acid. Paradoxically, both tryptophan‐low and tryptophan‐rich diets have been found to decrease weight gain in rats, however, the mechanisms are not clear.

Energy and water‐electrolyte balance were evaluated in 12‐week‐old, male, Sprague Dawley rats maintained on either control diet (TC) or tryptophan‐high (TH) or tryptophan‐low (TL) or control diet with neomycin, an antibiotic (TCA), for 10 days. Feces and blood levels of tryptophan and its bacterial metabolites were evaluated using chromatography coupled with mass spectrometry.

TL rats showed reduction in body weight. TH showed body weight gain, however, it was significantly lower than in TC and TCA rats. TL rats showed significantly lower blood level of tryptophan and its bacterial derivatives including indoxyl sulfate and indole‐3‐propionic acid (I‐3‐P). TH rats had significantly higher blood tryptophan level comparing to TL rats. I‐3‐P in feces and in portal blood of TH rats was significantly higher comparing to TC, TL and TCA rats. In a separate series of experiments rats treated daily i.p. with I‐3‐P showed significantly smaller weight gain than rats treated with the vehicle.

Our study suggests that tryptophan‐rich diet has a negative effect on energy balance via I‐3‐P, a gut bacteria metabolite of tryptophan. In contrast, tryptophan‐deficient diet may reduce weight due to the deficiency of the essential amino acid and decreased anabolism.

Support or Funding Information

Supported by the Ministry of Science and Higher Education Republic of Poland, Diamond grant DI2016 007346

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Elevated Plasma Endothelin‐1 is Associated with Reduced Weight Loss Post‐Vertical Sleeve Gastrectomy
Authors: Jenkins Haley N , Williams London J , Dungey Adam S , Vick Kenneth D , Grayson Bernadette E , Speed Joshua S
Published: June 2021

Current research supports that obesity and insulin resistance are positively correlated with plasma endothelin‐1 (ET‐1) levels; however, the mechanisms leading to this increase in ET‐1 are not fully understood. Similarly, while some physiological effects of ET‐1 have been characterized, the full complexity of this hormone has yet to be described in tissues outside of the vascular system. To date, one of the best treatments available for morbid obesity, cardiovascular disease, and metabolic syndrome is bariatric surgery to quickly reduce body fat and the factors associated with obesity‐related disease. We hypothesize that vertical sleeve gastrectomy (VSG) will reduce plasma ET‐1 levels. This was tested by measuring plasma ET‐1 levels from twelve obese patients before VSG, 6 weeks after, and 6 months after surgery. The results indicate that 6 weeks following VSG, plasma ET‐1 levels increased by 24%; however, after 6 months, there was a 27% decrease compared to baseline. Average weight loss in this cohort was 11.3±2.4 percent body weight after 6 weeks and 21.4±5.7 percent body weight after 6 months. Interestingly, we observed an inverse relationship between baseline plasma ET‐1 and percent body weight loss 3 months (R2=0.45, p<0.05) and 6 months (R2=0.49, p=0.01) post bariatric surgery. Our results indicate that VSG reduces plasma ET‐1 levels, a possible mechanism for improved metabolic risk in these patients. These data also suggest that ET‐1 may inhibit weight loss or serve as a predictor of weight loss following bariatric surgery.

Support or Funding Information

This work is supported by NHLBI grant R00 HL127178 to JSS.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Early Life Stress‐Induced Increases in Adiposity in Mice are Prevented by the Adipose Tissue‐Specific Abrogation of Neuropeptide Y Receptor 2
Authors: Leachman Jacqueline Renee , Dalmasso Carolina , Jones Tucker , Seward Tanya , Taylor Bradley K , Loria Analia S
Published: June 2021

Stress has long been associated with the physiology of disease, however, its mechanism of action in obesity remains unknown. Neuropeptide Y (NPY) plays a critical role in the regulation of energy homeostasis acting in the central nervous system as an orexigenic agent resulting in feeding that particularly favors the ingestion of foods rich in carbohydrates. Peripherally, NPY stimulates lipid storage in white adipose tissue (WAT) via NPY receptor 2 (NPY2R) promoting adipocyte precursor proliferation, differentiation of preadipocytes into mature adipocytes, as well as lipogenesis and adipose tissue deposition. Under chronic stress, NPY is co‐released with catecholamines by sympathetic axons to stimulate increased fat storage. We have previously discovered that mice exposed to a model of early life stress, maternal separation and early weaning (MSEW), display increased adiposity at weaning. Thus, we hypothesized that knocking down NPY2R in adipose tissue using the cre‐lox technology could prevent increases in adiposity in mice exposed to MSEW. MSEW was performed by separating adipose tissue‐specific floxed NPYR2 pups from the dam for 4 to 8 hours during postnatal days (PD) 2 to 16, and weaned early on PD 17. Control mice remained undisturbed and were weaned on PD 21. Body weight and echoMRI were performed in all litters at postnatal day 21 and tissue samples were taken for genotyping. Despite no changes in BW, wild type (WT, Y2 floxed) mice exposed to MSEW showed a ~30 % increase in adiposity compared with control WT mice (7.5±0.6 vs. 5.6±0.3 % body fat, p<0.05). However, this increase in adiposity was abrogated in MSEW NPYR2 knock out mice (5.7±0.1 vs. 5.5±0.6 % body fat, p=NS). In addition, WT mice exposed to MSEW showed reduced ratio of the adipose tissue norepinephrine/NPY concentrations and increased NPY2R mRNA expression compared with control mice. Taken together, these data suggest that exposure to postnatal MSEW may induce a shift in co‐transmitter release by catecholaminergic neurons innervating the adipose tissue leading to an increase in adiposity.

Support or Funding Information

R01HF135158 to ASL, R01HL135158‐01A1S1 to JRL

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Exposure to Microbial Infection In Utero Has Long‐Term Effects on the Cardiovascular Response to Angiotensin II and Forebrain Gene Expression in Rats
Authors: Watkins Jacqueline , Von Chamier Maria , Brown Mary B , Hayward Linda
Published: June 2021

Prenatal stressors, such as low protein diet, maternal smoking, and chronic psychological stress, predispose offspring to cardiovascular disease later in life. Microbial infection during pregnancy also increases the risk of adverse offspring health outcomes, but it remains to be determined whether this form of prenatal “stress” also triggers long‐term changes in offspring cardiovascular health. Thus, the present study was undertaken to evaluate whether the cardiovascular response to angiotensin II (ANGII) is altered in adult offspring born to mothers exposed to a microbial infection late in pregnancy when compared to non‐exposed controls (CON). Using an established rodent model of prenatal maternal infection (INF), dams were exposed to the rat pathogen Mycoplasma pulmonis or to vehicle via intravenous injection, on day 14 of pregnancy. Following natural birth, pups were cross‐fostered to non‐infected dams. Preliminary data (n=6–8/group) demonstrate that INF modestly elevated body weight by ~25 gm, significantly reduced resting heart rate (HR) by ~30 bpm in both sexes (P<0.001), but did not change resting blood pressure (BP) at 14 wks of age compared to CON. When subjected to a subcutaneous injection of ANGII, the rise in BP was significantly elevated in both female (48±6 vs 18±3 mmHg; P<0.002) and male (51±4 vs 39±5 mmHg; P<0.03) INF offspring compared to CON. The compensatory drop in HR was not significant between INF vs CON in either sex, suggesting INF induces baroreflex dysfunction. Gene expression analysis of the amygdala identified significant changes in corticotrophin system gene expression in females but not males. These results indicate that prenatal stress associated with INF significantly alters both cardiovascular function and gene expression in the forebrain later in life, potentially increasing the likelihood for offspring to develop cardiovascular disease when exposed to a second chronic stressor.

Support or Funding Information

Funded by FL‐DOH James and Esther King Biomedical Research Grant (LH & MB).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Regulation of Natriuretic Peptide Receptor‐A Expression in Gene‐targeted Mice via Modulation of Histone 3 Acetylation and Methylation Levels
Authors: Kumar Prerna , Pandya Krishna , Pandey Kailash N.
Published: June 2021

Guanylyl cyclase/natriuretic peptide receptor‐A (GC‐A/NPRA) signaling plays a well‐defined role in the regulation of blood pressure and blood volume. Mice lacking functional Npr1 gene (coding for GC‐A/NPRA) exhibit hypertension, kidney disease, and heart failure; however, the mechanisms regulating Npr1 expression are not well understood. The objective of the present study was to determine the effect of class I histone deacetylase (HDAC) inhibitor, mocetinostat (MGCD0103) on the expression of Npr1 via modulation of epigenetic changes. Male and female (16–20 weeks old) Npr1 gene‐knockout heterozygous (1‐copy; Npr1+/−), wild‐type (2‐copy; Npr1+/+) and gene‐duplicated heterozygous (3‐copy; Npr1++/+) mice were injected intraperitoneally with MGCD0103 (2 mg/kg) at alternate days for 2‐weeks. The Western blot result showed that MGCD0103 significantly increased the renal NPRA protein levels in male and female mice compared with vehicle‐treated controls. Plasma cGMP levels were higher in female mice compared with male mice both before and after the treatment with MGCD0103. Renal HDAC activity was significantly higher (p < 0.05) in male mice than female mice; however, treatment with MGCD0103 significantly attenuated (p < 0.05) HDAC activity by 40% in male and ~50% in female animals. The histone acetyltransferase (HAT) activity was lower in untreated 1‐copy male mice compared with wild‐type mice and MGCD0103 treatment significantly increased HAT activity whereas no significant differences were observed in drug‐or vehicle‐treated female mice. Male and female mice showed differential renal acetylation levels of histone 3 at different lysine positions (H3‐K9, H3‐K18, and H3‐K27) and treatment with MGCD0103 significantly enhanced the acetylation levels of H3‐K9 and H3‐K27 in 1‐copy male mice and H3‐K18 in 1‐copy female mice. There was substantial decrease in methylation of suppressive histone marks (H3‐K9 and H3‐K27) in MGCD0103‐treated 1‐copy male and female mice. Male mice exhibited significantly higher systolic blood pressure (SBP) than female mice and treatment with MGCD0103 decreased SBP in both 1‐copy male (106 ± 0.6 vs. vehicle‐treated, 129 ± 1.9; mmHg) and female (97 ± 2.2 vs. vehicle‐treated, 110 ± 2.1 mmHg, p < 0.001) mice. The present results provide direct evidence that MGCD0103 epigenetically regulates NPRA expression in vivo in 1‐copy male and female haplotype mice, via attenuation of HDAC activity and increase in histone H3 acetylation levels. These findings will have important implications in prevention and treatment of hypertension and renal pathophysiological conditions under reduced NPRA signaling.

Support or Funding Information

This work was supported by NIH grants (HL057531 and HL062147) and a partial support from Tulane Carol Lavin Bernick grant award.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
CRISPR‐Cas9 Gene Editing Yields a Novel Rat Model of Cardiometabolic Disease
Authors: Clark Karen C , Wagner Valerie A , Malek Jacob A , Arroyo Alyssa E , Pearson Nicole A , Grobe Justin L , Kwitek Anne E
Published: June 2021

Despite strong evidence that the Metabolic Syndrome (MetS) and its defining features (central obesity, dyslipidemia, hypertension, hyperglycemia) are highly heritable, the genetic etiology is complex and relatively few causative genes are known. For this reason, we employ the Lyon Hypertensive (LH) rat, a well‐characterized polygenic inbred MetS model. Previous genetic and computational approaches identified a novel gene (C17h6orf52) as a putative master regulator of gene expression and oxidative phosphorylation with pleiotropic effects on body weight and blood pressure regulation.

In this study, two different frameshift mutations were generated independently by CRISPR‐Cas9 gene editing, producing either a 5 base pair deletion or a 10 base pair insertion in exon 2 of C17h6orf52, and females from the resulting mutant rat strains, designated M1 and M2, respectively, were characterized (Table 1). Herein, mutations in C17h6orf52 are shown to significantly increase blood pressure and serum cholesterol in vivo, despite no significant changes in body composition or body weight in LH‐derived female rats.

Either mutation appears to cause modest, but significant or nearly significant, increases in blood pressure on a 0.3% NaCl diet. M1−/− females exhibit significantly increased systolic and diastolic blood pressure, while M2−/− females' systolic and diastolic blood pressure is more moderately elevated. This effect is potentiated when animals are administered a high salt diet. Finally, although neither total nor low‐density lipoprotein (LDL) cholesterol is changed in the M1 female rats with respect to their wildtype control, M2 females develop higher serum cholesterol, as well as significantly higher LDL cholesterol.

The differences in phenotype between the M1 and M2 mutations were unexpected. Preliminary data indicates that 5 base pair deletion present in the M1−/− rats results in two distinct splicing variants that may be contributing to the observed phenotype differences. Nevertheless, these data suggest that C17h6orf52 is protective against cardiometabolic risk factors, given that C17h6orf52 mRNA is more highly expressed in MetS‐susceptible LH rats than MetS resistant Lyon Normotensive (LN) rats, and the mutation confers a greater burden of MetS features on an already obese and hypertensive rat. The continued study of this rat model of Metabolic Syndrome has the potential to functionally validate an uncharacterized regulatory gene, and provide novel targets for pharmacological intervention in the treatment of obesity.

Support or Funding Information

R01HL089895, R21DK089417, T32GM008629, 14GRNT20410043

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Being a First Time Flipper is Challenging and Worthwhile to Increase Student Understanding of Cell Signaling
Authors: Halpin Patricia A. , Gopalan Chaya
Published: June 2021

To learn more about creating a Flipped Classroom, I attended a full day workshop on Flipped Teaching and Retrieval Practice (FT‐RP) at Southern Illinois University Edwardsville. This instructional strategy was then integrated into my BSCI 735 cell biology class. Two weeks in advance, the 17 students (juniors and seniors) were notified that the class would be flipped and the student expectations for that class meeting were described. Cell signaling was the subject chosen because students often have difficulty understanding the different pathways of steroid and peptide hormones. In advance of the class meeting, students watched a YouTube video on cell signaling and reviewed a PowerPoint outline. At the beginning of the class period, students took a multiple choice quiz on the subject and then participated in two types of cell signaling dramatizations. For the dramatization of the mechanism of action of steroid hormones, each student wore a placard with an assigned role: steroid hormone, plasma membrane, intracellular receptor, nuclear pore, and DNA. With the guidance of the instructor, students participated in the signaling cascade that began with the steroid hormone diffusing through the plasma membrane. The students switched roles and the activity was repeated. For the dramatization of the mechanism of action of peptide hormones, each student wore a placard with an assigned role: ligand, receptor, G protein, adenylate cyclase, plasma membrane, ATP, protein kinase A, intracellular enzymes and ion channels. The students performed the dramatization that concluded with cAMP binding to protein kinase A (PKA). The exercise was repeated twice with students switching roles each time. In the final dramatization, the next level of complexity of the PKA pathway was added and additional roles were assigned: the regulatory and catalytic subunits of PKA, the nuclear pore, and DNA, while enzymes and ion channels moved to the nucleus. This signaling pathway ended with genes being activated, enzymes turned on and ion channels opened. At the end of the class, students took the same quiz to assess what they learned and all scores increased. The flipped teaching was successful as students were able to differentiate the cell signaling pathways of steroid and peptide hormones.

Support or Funding Information

APS‐Teaching Career Enhancement Award

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Preliminary assessment of the use of out‐of‐class video presentations for content review in an allied health pathophysiology course
Authors: Walton Kristen LW
Published: June 2021

The flipped classroom technique has continued to gain popularity in undergraduate and postgraduate biology and medical education in recent years. This technique generally involves delivery of lecture or other methods of content coverage assigned before class, while class time is instead spent on discussion or other, more active approaches to learning. This technique was implemented for a specific set of content in an upper division undergraduate pathophysiology course. The prerequisite for this course is a one‐semester anatomy and physiology (A&P) course. Although students have to earn a C or better in this prerequisite A&P in order to enroll in the pathophysiology, many students continue to struggle with some major topics in A&P, such as cardiovascular physiology. This makes it difficult to have meaningful discussion of the related pathophysiology without first reviewing content from the prerequisite course. This project aimed to assess the use of pre‐class video lectures as a replacement for in‐class prerequisite course content review. Short (15–30 minute) video lectures were created and made available through the course management system 1–2 class meetings before the related pathophysiology content was covered in class. Students were required to complete an online multiple choice quiz that included questions from the video lecture content. For this preliminary study, data was analyzed for a 19‐minute video review of the cardiovascular system and the related quiz and exam questions. Out of 77 students enrolled in the class, 44 (57%) accessed the video through the course management system prior to the specific deadline; an additional 9 students (12%) accessed the video before the unit exam that included that topic. By the date of the exam, 56 students (73%) had watched the entire video. Five students accessed the video but watched less than half of it. Over 90% of students correctly answered the two multiple choice questions associated with this content in the untimed online quiz (91% for one question, 93% for the other question). A different multiple choice question over this review content appeared on the unit exam; 66% of students answered this question correctly. The average grade on this unit exam, which included cardiovascular pathophysiology as well as three other chapters, was 70.6%. In the previous semester, 62% of students (41 of 66 completing the exam) answered the same multiple choice question correctly, while the average on the full exam was 73.0% . These data support a conclusion that shifting review content to a pre‐class, video lecture format did not strongly impair student learning. Future studies will expand the number of topics analyzed to further assess the impact of pre‐class video lectures for review content on student learning in this course.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.