bluuebunny/crossref_metadata_2025 huggingface dataset:
Associations between Aerobic Capacity, Hepatic Bile Acid Synthesis and Fecal Bile Acid Concentration in Humans
Authors: Maurer Adrianna , Mercer Kelly E. , Adams Sean H. , Thyfault John
Published: June 2021

High aerobic capacity protects against a wide range of metabolic diseases and associates with changes in liver metabolism including enhanced mitochondrial function, although mechanisms remain unknown. Bile acids are now seen as active players in metabolic regulation. We have previously found that rodents with high aerobic capacity potentially have the ability to divert excess acetyl‐CoA away from de novo lipogenesis and toward bile acid synthesis and fecal excretion. To determine if the fitness‐bile acid association manifests in humans, in a preliminary study we tested the hypothesis that female subjects screened for high aerobic fitness (Hi‐Fit, n=10) (VO2peak>45 ml/kg/min) also have increased hepatic bile acid synthesis and fecal excretion compared to those matched for age and body mass with low aerobic fitness (Lo‐Fit, n=10) (VO2peak<35 ml/kg/min). Diet intake, activity level, stool, and blood were measured at baseline before receiving a 1 week standardized, weight‐maintaining eucaloric diet. After the 1week standardized diet, stool and blood were again measured, and an Oral Glucose Tolerance Test (OGTT) was performed. Hi‐fit women tended to have higher bile acid synthesis via measured serum 7α‐hydroxy‐4‐cholesten‐3‐one (C4), a clinically proven surrogate of bile acid production, both during fasting (p≈0.16) and following the OGTT (p≈0.06). However, no significant differences in circulating or fecal bile acid concentrations were found. Future research should consider using direct tracer measurements of bile acid synthesis and excretion, and the utilization of 24 hr+ fecal bile acid measures to quantify total production and excretion.

Support or Funding Information

USDA‐Agricultural Research Service 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.
FGGY Carbohydrate Kinase Domain Containing (Fggy) is Expressed and Alternatively Spliced in Skeletal Muscle
Authors: Izhar Mahnoor , Smith Anastasia , Waddell David
Published: June 2021

Skeletal muscle atrophy can result from a range of physiological conditions, including denervation, corticosteroid exposure, immobilization and aging. In order to better characterize the molecular genetic events of atrophy, a previous investigation isolated skeletal muscle from mice following 3 days and 14 days of denervation. The gene expression profile of the denervated muscle tissue was analyzed by microarray and compared to control muscle in order to identify novel atrophy‐induced genes. The microarray revealed that FGGY carbohydrate kinase domain containing (Fggy) is expressed in skeletal muscle and is induced in response to denervation. Bioinformatic analysis of the Fggy gene locus revealed two validated alternative isoforms, which we have termed Fggy‐L and Fggy‐S, that have distinct transcription initiation sites. In order to confirm that Fggy is expressed in muscle cells, the cDNAs of the two validated alternative splice variants were cloned from mouse myoblast cells. Interestingly, a novel alternative spice variant for each of the validated alternative isoforms was also cloned from mouse muscle cells, suggesting that at least four Fggy variants are expressed in skeletal muscle. In order to better characterize the expression profile of the Fggy gene, quantitative RT‐PCR (RT‐qPCR) was performed using RNA isolated from muscle cells and primer pairs that distinguish all four alternative Fggy transcripts. The qPCR data revealed that the Fggy‐L transcripts are more highly expressed in proliferating muscle cells, while the Fggy‐S transcripts are more evenly expressed in muscle cells that are both proliferating and differentiated. Western Blot analysis of protein homogenates isolated from muscle cells confirmed that the Fggy‐L isoform is more highly expressed in proliferating muscle cells, while the Fggy‐S isoform is more ubiquitously expressed. In addition, confocal fluorescent microscopy analysis showed that the Fggy‐L full length and novel proteins are localized throughout the cell, while the Fggy‐S full length and novel gene products produce a punctuate pattern throughout the cytoplasm of muscle cells. Finally, ectopic expression of Fggy in cultured muscle cells resulted in significant inhibition of muscle cell differentiation. The characterization of novel genes that are activated during neurogenic atrophy helps improve our understanding of the molecular and cellular events that lead to muscle atrophy and could eventually lead to new therapeutic targets for the treatment of muscle wasting.

Support or Funding Information

The work was support by University of North Florida Transformational Learning Opportunity grants and a University of North Florida Foundation Board Grant to D.W.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Ubiquitin Specific Peptidase 3 (USP3) is Expressed in Skeletal Muscle and is Upregulated in Response to Neurogenic Atrophy
Authors: Cruikshank Aimee , Waddell David
Published: June 2021

Skeletal muscle atrophy is a physiological condition that is caused by a variety of conditions, including immobilization, denervation, spinal cord injury and aging and results in decreased muscle size and strength. To better characterize the molecular genetic events of neurogenic atrophy, a previous study isolated gastrocnemius muscle from mice following 3 days and 14 days of denervation. The gene expression profile in the denervated muscle tissue was then analyzed by microarray and compared to control muscle tissue to identify novel neurogenic atrophy‐induced genes. The microarray data revealed for the first time that Ubiquitin Specific Peptidase 3 (USP3) is expressed in skeletal muscle and is significantly induced in response to denervation at 3 days post‐denervation but returns to baseline expression levels by 14 days post‐denervation. USP3 is a deubiquitinase that has been shown previously to stabilize p53 by deubiquitination. To confirm that USP3 is expressed in skeletal muscle, we cloned the USP3 cDNA from cultured muscle cells. In addition, quantitative PCR (qPCR) was performed to assess USP3 expression levels in both proliferating and differentiated muscle cells and the results demonstrate that USP3 expression levels are relatively equal in both proliferating myoblasts and in differentiated myotubes. Furthermore, Western blot analysis of protein lysates isolated from proliferating and differentiating muscle cells revealed that USP3 is expressed in proliferating myoblasts, but then decreases modestly as the cells differentiate in culture. The discovery that USP3 is induced in response to neurogenic atrophy helps further our understanding of the molecular genetic events of atrophy and may eventually lead to the identification of new therapeutic targets for the treatment and prevention of muscle wasting.

Support or Funding Information

The work was support by University of North Florida Transformational Learning Opportunity grants and a University of North Florida Foundation Board Grant to D.W.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Identification and Characterization of Homocysteine Responsive Endoplasmic Reticulum Resident Ubiquitin‐like Domain Member 2 (Herpud2) in Skeletal Muscle
Authors: Arcaro Alexandra , Hewitt Lillian , Waddell David
Published: June 2021

Skeletal muscle atrophy is a physiological condition that is caused by disparate conditions, including immobilization, denervation, spinal cord injury and corticosteroids and results in decreased muscle size and strength. To better characterize the molecular genetic events of neurogenic atrophy, a previous study isolated gastrocnemius muscle from mice following 3 days and 14 days of sciatic nerve denervation. The gene expression profile in the denervated muscle tissue was then analyzed by microarray and compared to control muscle tissue to identify novel neurogenic atrophy‐induced genes. The microarray data revealed for the first time that Homocysteine Responsive Endoplasmic Reticulum Resident Ubiquitin‐like Domain Member 2 (Herpud2) is expressed in skeletal muscle and is differentially regulated in response to denervation. Herpud2 is related to Herpud1, which has previously been shown to play a role in endoplasmic reticulum‐associated degradation (ERAD) of unfolded ER proteins via retrotranslocation to the cytoplasm and degradation by ubiquitin‐proteasome system. To confirm that Herpud2 is expressed in muscle cells, we cloned the Herpud2 cDNA from cultured cells and performed quantitative PCR (qPCR) to assess Herpud2 expression levels in both proliferating and differentiated muscle cells and the results demonstrate that Herpud2 expression levels are lower in proliferating myoblasts compared to differentiated myotubes. Furthermore, Western blot analysis confirmed that Herpud2 is expressed in cultured muscle cells at the protein level. The discovery that Herpud2 is differentially expressed in response to neurogenic atrophy helps further our understanding of the molecular genetic events of muscle wasting and may eventually lead to the identification of new therapeutic targets for the treatment and prevention of atrophy.

Support or Funding Information

The work was support by University of North Florida Transformational Learning Opportunity grants and a University of North Florida Foundation Board Grant to D.W.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Increased Protein Intake Prevents Elevations in Sclerostin during Short‐Term Diet‐ and Exercise‐Induced Weight Loss
Authors: Murphy Chaise , Marks‐Nelson Eileen , Koehler Karsten
Published: June 2021

Caloric‐restriction is necessary for efficacious weight loss, but can lead to unwanted losses of lean mass and bone mineral content. High‐protein diets have been shown to protect lean mass during caloric‐restriction and may have similarly preservative effects on bone either through attenuating increases in bone resorption or elevating bone formation.

Objectives

To determine whether increasing protein intake, in combination with daily aerobic exercise, attenuates elevations in bone resorption markers and reductions in bone formation markers during short‐term severe caloric‐restriction in healthy, active men. We hypothesized increasing protein intake would attenuate elevations in sclerostin and c‐terminal telopeptide (CTX) while maintaining levels of procollagen type I propeptide (P1NP).

Methods

In this randomized crossover trial, participants underwent three conditions: caloric‐restriction with low protein intake (CRLP; 0.8 g/kg body weight (BW)); caloric‐restriction with high protein intake (CRHP; 1.7 g/kg BW) and energy balance control (CON; 1.7 g/kg BW). Caloric restriction was achieved by reducing energy availability, calculated as the difference between dietary energy intake and exercise energy expenditure, to 15 kcal/kg fat‐free mass (FFM), whereas energy availability was maintained at 40 kcal/kg FFM in CON. Throughout all conditions, participants completed daily supervised exercise sessions on a bicycle ergometer set to expend 15 kcal/kg FFM. Before and after each five‐day condition, body composition was assessed via bioimpedance analysis and markers of bone formation and resorption were assessed from fasting blood samples.

Results

Body weight decreased (p < 0.001) in CRLP [−1.97 ± 0.22 kg] and CRHP [−1.80 ± 0.52 kg], but remained stable in CON. Loss of fat mass was significant in CRHP [−1.14 ± 0.23 kg, p < 0.05] but not in CRLP [−0.57 ± 0.48 kg]. Sclerostin was elevated above baseline levels only in CRLP [19.7 ± 22.5 %, p < 0.05] but not in CRHP [3.2 ± 18.3 %] or CON [3.7 ± 26.1 %]. CTX was reduced in CON [−8.9 ± 9.8 %, p < 0.05] but did not change in CRHP [0.1 ± 5.4 %] or CRLP [3.8 ± 14.7 %]. P1NP did not change significantly in any group.

Conclusions

Elevating protein intake and performing daily aerobic exercise during five days of severe caloric restriction suppressed the elevation in sclerostin, a bone resorption marker, seen in individuals who performed daily aerobic exercise but did not elevate protein intake. This effect mirrors the protective effect of increased protein intake on lean mass.

Support or Funding Information

This work was supported in part by funding from the USDA National Institute of Food and Agriculture (NEB‐36‐083) and a Layman Seed Award from the University of Nebraska 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.
MiR‐29b levels in Cord Blood from Preterm Infants Are Associated with Fetal Inflammation
Authors: Pavlek Leeann R , Vudatala Sundari , Warnement Catherine M , Heyob Kathryn M , Buhimschi Irina M , Buhimschi Catalin , Rogers Lynette
Published: June 2021

Background

Previous reports have identified decreases in miR‐29b levels in preterm infants that go on to develop bronchopulmonary dysplasia (BPD). The cause of depressed miR‐29b levels is unknown but may reflect an adverse maternal and/or intrauterine environment that led to preterm birth. This study was designed to investigate relationships between antenatal circumstances related to preterm birth and cord blood levels of miR29b.

Methods

We analyzed 127 cord blood collected from consecutive deliveries (n=114) of liveborn infants born ≤30 weeks gestation (median 27.4 weeks: IQR [25.6–29.0]). Data on maternal co‐morbidities, antecendants to preterm birth (e.g., preeclampsia, fetal growth restriction, placental inflammation) were collected prospectively. miR‐29b levels were measured using RT‐PCR and normalized to expression of SP2. Data were analyzed for correlations by Spearman's correlation coefficient or Generalizing Estimating Equations (GEE) for mixed models controlling for twins.

Results

Preliminary results indicate that miR‐29b levels were correlated to umbilical funisitis (p=0.038). Regression analysis revealed miR‐29b is associated with intrauterine growth retardation (p=0.011) and pre‐term labor (p=0.007).

Conclusions

miR‐29b levels are associated with fetal inflammation and poor fetal growth. Maternal health is also related to fetal inflammation and further analyses of the clinical data is likely to reveal new correlations.

Support or Funding Information

NIH NICHD R01HD088033

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Deletion of miR‐92a Results in Glucose Intolerance via Impaired Pancreatic Beta Cell Function
Authors: Islam Md Torikul , Tippetts Trevor S , Gogulamudi Venkateswara R , Holland William L , Summers Scott A , Donato Anthony J , Lesniewski Lisa A
Published: June 2021

MicroRNAs (miRs) are small non‐coding RNA that regulate numerous physiological and pathological processes by repressing protein translation. MiR‐92a, a member of the miR‐17–92 cluster, is altered during development and in a host of disease states, with pancreatic miR‐92a levels reduced in animal models of diabetes. Here, we tested the hypothesis that miR‐92a is a critical regulator of metabolism that modulates pancreatic beta cell function and glucose homeostasis. Glucose tolerance and insulin sensitivity were assessed by glucose (2 g/kg, ip) and insulin (1 U/kg, ip) tolerance tests, respectively in wildtype (WT: C57Bl/6) and whole body miR‐92a (miR‐92a−/−) knockout mice. Deletion of miR‐92a impaired glucose tolerance (p<0.01), but not insulin sensitivity (p>0.05), compared to WT mice. To explore the potential causes of this glucose intolerance, we assessed both fasted insulin and glucose‐stimulated (1 g/kg, ip, 5 min) insulin secretion (GSIS), and found both to be lower in miR‐92a−/− mice compared to WT mice (both p<0.01). To examine if miR‐92a modulates insulin secretory capacity, we administered 10% L‐arginine (1 g/kg, ip) and a β‐adrenergic agonist (CL 316,243: 1 mg/kg, ip) following a 4–6 hr fast and plasma insulin was assessed at time 0, 5 and 15 min. Fasted plasma insulin was ~70% lower in miR‐92a−/− mice compared to WT mice (p<0.01). In response to L‐arginine, plasma insulin was lower in miR‐92a−/− mice compared to WT mice (1.80 ± 0.52 vs 4.57 ± 0.62, 5 min, p<0.01; 1.23 ± 0.42 vs 6.30 ± 2.66, 15 min, p<0.05). Likewise, plasma insulin was ~3 and ~8‐fold lower at 5‐ and 15‐min after β‐adrenergic stimulation in miR‐92a−/− mice compared to WT mice (both p<0.01). Taken together, these results indicate a reduced insulin secretory capacity in response to glucose, amino acid and lipid stimulation in miR‐92a−/− mice. Subsequent histological analysis demonstrated that both average islet size and extrapolated total islet mass were ~50% less in miR‐92a−/− mice compared to WT mice (both p<0.05). In conclusion, our findings support a critical role for miR‐92a in pancreatic beta cell function and whole body metabolic homeostasis.

Support or Funding Information

This work was supported in part by awards from the National Institute on Aging, R01 AG048366, R01 AG050238, and K02 AG045339, and by Merit Review Award 1I01BX002151 from the United States (U.S.) Department of Veterans Affairs Biomedical Laboratory Research and Development Service.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Altered Non‐Coding RNA‐Histone Acetylation Regulatory Circuit Is Associated With Cognitive Impairment via Gut Dysbiosis in Aging Mice
Authors: Behera Jyotirmaya , Kelly Kimberly E. , Tyagi Neetu
Published: June 2021

Advancing age is the top risk factor for the development of neurodegenerative disorders such as Alzheimer's Disease (AD). However, the contribution of the aging process to Alzheimer's disease (AD) pathology remain unclear. It is also unclear, whether age‐related disruption of the gut‐barrier integrity or dysbiosis causes impaired hippocampal memory. Allyl sulfide (AS), an organic sulfur compound in garlic, has many health benefits and is known for its detoxifying agents. However, the precise role of allyl sulfide in regulating hippocampal memory function at mechanistic levels in mice still needs to be investigated. Here we show that memory disturbances with altered hippocampal chromatin plasticity in the aging brain of the mouse are associated with gut‐microbiota changes and intragastric administration of allyl sulfide retards age‐related defects. To test the hypothesis, we employed 4‐months age‐matched male wild‐type C57BJ/L6 (WT) mice as control group (Young), 24‐months old age‐matched male WT mice group as aging group (AG) and another 24‐months old age‐matched male WT mice group received daily AS at the dosage of 2mg/kg/b.wt through oral gavage (AG+AS). The results show that Young and AG+AS mice showed higher behavioral proficiency and more robust long‐term and short‐term memory compared to AG mice. Gut microbiota is significantly altered as assessed by the denaturing gradient gel electrophoresis (DGGE) analysis in AG group in compared with Young and AG+AS group. The mechanistic study shows that AG mice display an increased plasma level of circulating non‐coding RNA‐Hotair (lncRNA‐Hotair), as assessed by RT2 lncRNA qPCR Assay. To test whether memory impairment correlates with altered hippocampal chromatin plasticity in a lncRNA‐Hotair dependent manner, we first investigated the hippocampal histone acetylation pattern in the AG group. The data suggest that lncRNA‐Hotair causes a specific deregulation of histone H3 lysine 27 (H3K27) acetylation (ac) at the neuronal derived natriuretic factor (NDNF) promoter of hippocampal tissue of AG group and, therefore, fail to initiate a hippocampal gene transcription associated with memory consolidation. However, administration of AS in the AG group could ameliorate gut dysbiosis and memory functions. In lncRNA‐Hotair‐deficient mice, which are protected from age‐related microbiota changes and memory impairment. Furthermore, restoration of NDNF using recombinant NDNF‐therapy reinstates to the recovery of cognitive abilities. In conclusion, our data suggest that lncRNA‐Hotair upregulation and H3K27ac regulatory activity may represent an early biomarker in the aging mouse brain. In addition, AS could serve as potential anti‐aging therapeutics in treating aging individuals.

Support or Funding Information

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‐mediated deletion of a regulatory element downstream of the EDN1 gene increases expression of a long non‐coding RNA, EDN1‐AS
Authors: Douma Lauren G , Masten Sarah , Solocinski Kristen , Barral Dominique , Wingo Charles S , Cain Brian D , Gumz Michelle L
Published: June 2021

Endothelin‐1 (ET‐1) is a peptide hormone that functions as a vasoconstrictor in the vasculature whereas in the collecting duct of the kidney it exerts blood pressure‐lowering effects via natriuretic actions. Aberrant ET‐1 signaling is associated with several pathological states including hypertension and chronic kidney disease. ET‐1 expression is regulated largely through transcriptional control of the gene that encodes ET‐1, Edn1. We recently discovered a long, non‐coding RNA (lncRNA) that appears to be antisense to the Edn1 gene, called EDN1‐AS. Because EDN1‐AS represents a potential novel mechanism to regulate ET‐1 expression, we examined the molecular regulation of EDN1‐AS expression and action. Using the ENCODE database and the UCSC genome browser, we located a putative glucocorticoid receptor response (GR) element upstream of the predicted transcription start site for EDN1‐AS. Preliminary chromatin immunoprecipitation results indicated that both GR and the circadian clock protein PER1 interact with this region of DNA in human renal proximal tubule HK‐2 cells. Using CRISPR, we deleted the region containing this potential regulatory element. Two homozygous deletion clones were identified following selection with puromycin (A11 and H3). An HK‐2 clone that went through the same selection procedure but was negative for the deletion served as the control cell cline. This deletion resulted in a significant increase in the expression of EDN1‐AS (2 fold, n=3–4, p<0.05). This increase in EDN1‐AS expression was associated with increased secretion of ET‐1 peptide from HK‐2 cells (KO H3=1.68 pg/mg vs. control line F1=1.53pg/mg, n=4, p= 0.004). Phenotypic characterization of these CRISPR clones revealed a difference in cell growth rates. Using a standard growth assay, we determined that the A11 clone exhibited a 3 fold increase in growth over 8 days compared to control cells (n=4, P<0.0001) and the H3 clone exhibited a 2 fold increase (n=4, p<0.001). These results support a role for EDN1‐AS as a novel regulatory mechanism of ET‐1 expression and cellular proliferation.

Support or Funding Information

NIH T32DK104721 (LGD), NIH R21AG052861 (MLG), The Gatorade Trust through the UF Department of Medicine

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Modeling the 20‐HETE Binding Site on GPR75
Authors: Garcia Victor G , Gilani Ankit , Agostinucci Kevin , Adebesin Adeniyi , Falck John R , Schwartzman Michal L
Published: June 2021

Recently, the cytochrome P450‐derived eicosanoid 20‐Hydroxyeicosatetraenoic acid (20‐HETE) was shown to activate the orphan receptor GPR75. The pairing of 20‐HETE and GPR75 activates a signaling pathway that elicits increases in endothelial angiotensin converting enzyme (ACE) and promotes the development of hypertension. Little is known about the critical binding sites/pockets across GPR75 involved in interacting with 20‐HETE that ultimately leads to receptor activation. Computational docking analysis of GPR75 uncovered a putative ligand binding site located between transmembranes five and six on GPR75 (SiteScore: 1.182 and Dscore: 1.303). Independent analyses of ligand‐receptor docking using 20‐HETE placed the lipid in close proximity to the putative binding pocket (Docking Score: −3.229, Glide Emodel: −29.045). Additional modeling of GPR75 alongside another proposed ligand, the chemokine CCL5 (RANTES), revealed a potential protein‐protein interaction model occurring at the top (extracellular face) between the first and seventh transmembranes of GPR75. This distant site suggests the possibility of distinct ligand‐receptor interactions that promote unique signaling cascades. In order to establish a functional assay to further investigate the significance of the proposed 20‐HETE binding site/pocket, we have adapted the PRESTO‐Tango system. This system allows for the quantification of ligand‐dependent β‐arresstin2 recruitment, a common hallmark of G‐protein coupled receptor activation, biased agonism and receptor inactivation/internalization. Preliminary studies using the GPR75‐Tango construct demonstrated a robust signal wherein 20‐HETE stimulates the recruitment of β‐arresstin2 after GPR75 activation (EC50=3μM). Further studies will be conducted to assess the significance of residues located within the putative binding pocket with respect to 20‐HETE‐mediated activation of GPR75.

Support or Funding Information

This study was supported by National Institute of Health grants HL39793(M.L. Schwartzman), HL39793‐01S1 (V. Garcia) and the Robert A. Welch Foundation (I‐0011, J.R. Falck).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
A human‐origin probiotics cocktail exhibit cardio‐protective effects independent of GLP‐1 receptor signaling
Authors: Nagpal Ravinder , Mishra Sidharth P , Wang Shaohua , Tallant Ann , Varagic Jasmina , Kitzman Dalane , Yadav Hariom
Published: June 2021

The emerging role of the gut microbiome in cardiovascular diseases is posited to be mediated by the microbial metabolites, some of which yield beneficial effects while others may accelerate the heart diseases. The beneficial metabolites like short‐chain fatty acids, particularly butyrate, exhibit several beneficial effects on metabolic diseases including cardiovascular functions. We have previously demonstrated that butyrate promotes the production of glucagon‐like protein‐1 (GLP‐1). GLP‐1 and its therapeutic agonists are known to promote cardiovascular functions. Herein, we investigated the role of systemic deletion of GLP‐1 receptor (using GLP1R KO) on cardiac functions in 16 weeks high‐fat diet (HFD)‐fed obese mice and assessed the impact of feeding a butyrate‐producing probiotic cocktail (consisting 5 Lactobacillus and 5 Enterococcus strains isolated from infant's gut) on cardiac functions, using the non‐invasive high‐frequency ultrasound echocardiography system (VEVO, VisualSonics, Toronto, Ontario, Canada). GLP1R‐KO mice show reduced cardiac output and stroke volume, and higher ejection fraction and fractional shortening of the left ventricle compared GLP1R‐WT mice. In addition, the GLP1R‐KO mice also exhibited significantly reduced systolic and diastolic diameter and volume, along with higher ratio of aortic acceleration and ejection time. Interestingly, feeding of probiotic cocktail protected from such dysfunctions in GLP‐KO mice, and also all these measures remain unchanged in GLP‐WT mice with and without probiotics treatments. No significant differences in body weight and diet intake was observed, however, glucose and insulin tolerance tests were improved in both probiotic‐fed groups. Results indicate that GLP1‐receptor depletion causes cardiovascular dysfunctions and feeding of the human‐origin probiotic cocktail ameliorates such dysfunctions, and probiotics effects are independent of GLP‐1 receptor signaling. Further analyses to better understand the mechanisms of actions of probiotics cocktail contributing these effects, are directed to establish a new cardioprotective probiotic biotherapy in obesity and type 2 diabetes.

Support or Funding Information

We thank the support provide by Center of Cardiovascular Sciences Center, Wake Forest School of Medicine, and the Department of Defense funding PR170446, as well funds and services provided from Center for Diabetes, Obesity and Metabolism, Wake Forest Baptist Medical Center and National Center for Advancing Translational Sciences (NCATS), National Institutes of Health funded Wake Forest Clinical and Translational Science Institute (WF CTSI) through Grant Award Number UL1TR001420.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Left and right superior cervical ganglionectomy affect differently the cardiorespiratory patterning in the in situ arterially perfused brainstem preparation of the rat
Authors: Kola Gjinovefa , Coffee Gregory A , Getsy Paulina M , Hsieh Yee‐Hsee , Dick Thomas E , Dutschmann Mathias , Lewis Stephen J
Published: June 2021

The superior cervical ganglia project to the nucleus tractus solitarii, modulate vasomotor tone and buffer cardio‐respiratory responses to chemoreceptor activation. Here, we report the differential effect of left versus right superior cervical ganglionectomy (SCGx) on cardiorespiratory activity in the in situ arterially perfused brainstem preparation. For these studies, we used male Sprague‐Dawley rat pups (P25). Four days after removal of either the left or right superior cervical ganglia (n=20, 10 in each side) or sham surgery (n=10), we recorded left and right phrenic (PNA) and cervical vagal (VNA) nerve activities, and monitored perfusion pressure. ‘Fictive’ cardio‐respiratory patterns were recorded for 10 min (baseline) and then in response to peripheral chemoreceptor activation (intra‐arterial injection of sodium cyanide, 100 μL of a 0.03% solution). At baseline and during the response to chemoreceptor stimulation, the left and right PNA and VNA were similar for all groups. At baseline, PNA burst frequency and amplitude were similar in the left‐, right‐ SCGx and sham groups but VNA was greatest for the left SGX group and the perfusion pressure had to be increased to maintain ‘fictive’ respiration for right‐SCGx group. During the chemoreceptor stimulation, the fR response was greatest for the sham group and greater for the right‐ than the left‐SCGx group. In contrast, the PNA amplitude response was greatest for right‐SCGx group and comparable for the left‐SCGx and sham groups. Despite the increase in baseline VNA, the increase in VNA response to chemo‐stimulation was similar for the left‐, right‐SCGx and sham groups. Finally, the left‐SCGx group had smallest increase in PP during chemoreceptor stimulation. These data indicate that the left and right superior cervical ganglia modulate vasomotor tone respiratory patterning differentially at rest and during chemoreceptor reflexes.

Support or Funding Information

NIH SPARC 1OT2OD023860‐02 SJ Lewis

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
WormBeat: A Strategy to Evaluate Pharyngeal Pumping Variability in the Nematode C. elegans
Authors: Harris Michael B , Shilleh Ahmad , Phillips Derek , Taylor Barbara E , Berlemont Renaud
Published: June 2021

In C. elegans, the feeding behavior of pharyngeal pumping occurs spontaneously in proportion to metabolism and in response to stimuli. Age‐ and health‐related changes in tissue morphology and function correlate with declines in the frequency of pumping. As such, pumping frequency is an established index of C. elegans “health”, and pumping changes illustrate and quantify functional decline. Timing of pharyngeal pumping is controlled by two pairs of pharyngeal motor neurons (MC and M3). Each pump cycle corresponds to the propagation of a single pharyngeal muscle action potential, initiated by MC and terminated by M3. We currently model this system with MC acting as an oscillator and synaptically linked to the pharyngeal muscle. Pumping can change by influences on the pace and regularity of the oscillator and/or of the fidelity of pharyngeal muscle response to neuronal inputs.

Traditionally, this phenomenon has been reported as an occurrence frequency, describing the number of pumping events observed per unit time over a period of observation. Variation in pumping frequency within and between subjects, and the relative coarseness of this measure may interfere with the resolution of subtle treatment effects and ignores both the mechanisms for resulting effects as well as the potential significance of pumping variability.

We use the recently developed ScreenChip system (NemaMetrix) to detect individual pump events, and have developed an algorithm (WormBeat) to normalize variation between subjects and distinguish variability associated with MC neuron pace and neuromuscular fidelity of the pharynx. We present the validity of our algorithm and demonstrate enhanced resolution in detecting differences in pumping behavior using simulations representing ranges and distinct sources of biologically relevant variability. This presentation describes the theory and practice of the algorithm. The use of this analysis strategy on an experimental dataset is described in a companion presentation.

Support or Funding Information

Work reported in this publication was supported by the National Heart Lung and Blood Institute and National Institute of General Medical Sciences of the National Institutes of Health under Award Numbers 1R15HL126105, 1SC2GM112570, UL1GM118979, TL4GM118980, and RL5GM118978. The work is solely the responsibility of the authors and does not necessarily represent the official view of the National Institutes of Health or any other funding body.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Hypoxia Induces Emergence of Adult‐like Respiratory Motor Patterns in Pre‐metamorphic Bullfrog Brainstem Preparations
Authors: Janes Tara , Kinkead Richard
Published: June 2021

Vertebrate respiratory development involves the gradual transformation of primal respiratory behaviours into mature forms with specific, measurable characteristics. Yet, the impacts of environmental factors on respiratory maturation remain enigmatic. In pre‐metamorphic tadpoles of Lithobates catesbeianus (American bullfrog), gill ventilation predominates, while lung breathing is rarely observed. Following metamorphosis, lung breathing emerges as the dominant respiratory behaviour. Since accelerated metamorphosis (including respiratory development) constitutes an adaptive response to deterioration of the milieu, we hypothesized that hypoxia is sufficient to accelerate maturation of the motor command for lung breathing. Specifically, we predicted that hypoxia would elicit an “adult‐like” motor pattern in pre‐metamorphic tadpoles, including high amplitude lung bursts occurring episodically with a “ramping up” of burst amplitude within episodes. Using early‐stage tadpoles (Taylor‐Kollros: VI–IX), we recorded respiratory motor activity from cranial nerves V, VII and X in isolated brainstems before, during, and 2h after exposure to 15 min of moderate hypoxia (PwO2 range: 45–76 Torr). To test for long‐term effects brainstems were then incubated overnight in oxygenated artificial cerebral spinal fluid at 17°C and motor activity recorded 24h post‐hypoxia. In line with our predictions, lung motor activity in brainstems exposed to hypoxia exhibited characteristics of adult breathing while that of time‐matched controls resembled typical tadpoles. Lung burst amplitude was increased relative to baseline (+90%) at 2h post‐hypoxia. Additionally, hypoxia increased the incidence of lung burst episodes more than 300%, with a concurrent increase in the number of breaths per episode from an average of 2.2 at baseline to 3.3 at 2h post‐hypoxia (controls: 1.9 at 2h). The “ramping up” of lung burst amplitude during episodes was variable over time but gradually increased in prevalence above control levels by 24h post‐hypoxia. These data demonstrate that central hypoxia induces the emergence of “adult‐like” lung motor patterns in early pre‐metamorphic tadpoles.

Support or Funding Information

This work was supported by a Fonds de Recherche du Québec ‐ Santé (FRQS) Collaborative Scholarship awarded to T. Janes and an NSERC Discovery Grant awarded to R. Kinkead.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Energetic cost of intestinal ion transport pathways in marine teleosts
Authors: Grosell Martin
Published: June 2021

A number of studies have attempted to determine the metabolic cost of osmoregulation in teleost fish by measuring standard or resting metabolic rates with the anticipation that metabolic demands would be lowest at isosmotic salinities. However, there is no consensus among these studies and estimates of osmoregulatory costs based on whole animal metabolic rates range from a 2–30% of resting metabolic rates. Both interspecies differences and difficulties in determining true standard metabolic rates not influenced by spontaneous activity/anxiety/stress contributes to the lack of consensus in field. Isolated osmoregulatory tissues have rarely been employed even though they avoid problems of organismal responses. The few studies using isolated tissues have focused on the gills and estimate cost in the range of 2–4%, a range that matches theoretical considerations. Such low metabolic demands are challenging to capture by measurements of intact animals. To date, no studies have attempted to quantify the metabolic demand of osmoregulatory processes by the marine teleost intestine despite its central role in osmoregulation. Multiple parallel Cl− uptake pathways with different energetic efficiency are present in the marine teleost intestinal epithelium and suggests osmoregulatory metabolic demands comparable to that of the gill tissue. The least expensive Cl− uptake pathway is via NKCC2 consuming 0.17 ATP/Cl− while anion exchange via SLC26a6 is consuming ≥ 1 ATP/Clyet, marine teleost fish employ the SLC26a6 pathway extensively. The theoretical intestinal contribution to marine teleost osmoregulation and the seemingly energetically expensive strategy of employing anion exchange will be presented.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Chemical and Physical Properties of Gill Plasma Membranes Are Altered in Response to Thermal Acclimation in the Antarctic Notothenioid Fish Notothenia coriiceps
Authors: Biederman Amanda M , Crockett Elizabeth L
Published: June 2021

Antarctic notothenioid fishes are highly stenothermal as a result of living under relatively stable conditions for millions of years. In a warming climate, preservation of membrane structure and function at elevated body temperatures will be critical to the survival of these species. Many ectothermic organisms can respond to thermal variation by altering membrane compositions to preserve membrane structure (i.e., homeoviscous adaptation). It is largely unknown to what extent Antarctic notothenioids possess the capacity to remodel their biological membranes in response to thermal change. We studied effects of thermal acclimation on physical (fluidity, permeability, oxygen solubility) and biochemical (lipid composition) properties of plasma membranes from the gills of an Antarctic notothenioid, Notothenia coriiceps. Animals were acclimated to 0 and 5°C for a minimum of 6 weeks. Plasma membranes were prepared from the gill, and membrane fluidity was measured from 0 to 30°C. Cholesterol contents and phospholipid compositions were analyzed in membranes, and permeability to water was measured in gills at both 0 and 4°C. Oxygen partition coefficients were determined in membrane samples to assess oxygen solubility. Membrane fluidity was reduced in the 5°C‐acclimated group, compared with animals held at 0°C (P<0.0001) and exhibited perfect (100%) homeoviscous efficacy. Membranes from 5°C‐acclimated fish also contained 1.2‐fold greater cholesterol (P<0.01) and 1.1‐fold greater long‐chain fatty acids (i.e., fatty acids with at least 20 carbon molecules per chain) (P<0.05). Water permeability was reduced 1.5‐fold with 5°C acclimation (P<0.05), exhibiting near‐perfect (96%) homeostatic efficacy. In contrast, oxygen solubility of membrane lipids was unchanged. The biochemical alterations with acclimation are in accord with changes in both fluidity and permeability, suggesting lipid restructuring occurred to conserve membrane structure at elevated temperature. Taken together, these results provide evidence of homeoviscous adaptation, and conservation of permeability, with temperature acclimation in gill plasma membranes from an Antarctic notothenioid.

Support or Funding Information

Supported by NSF ANT 1341602 and the Ohio University Student Enhancement Award fund.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Ontogeny of renin gene expression and juxtaglomerular apparatus in birds
Authors: Hoy Jessica , Nishimura Hiroko , Yaoita Eishin , Gomez Robert Ariel , Sequiera‐Lopez Maria Luisa S
Published: June 2021

The renin‐angiotensin system (RAS) plays a crucial role in the regulation of blood pressure, fluid electrolyte homeostasis, and vascular development. Renin or a renin‐like enzyme evolved in primitive vertebrates and is conserved throughout the vertebrate phylogeny. The ontogenic development of renin, however, has not been well understood. We aimed to determine expression patterns and relative abundance of renin mRNA in pre‐ and postnatal chickens (Gallus gallus, White Leghorn breed) using primers designed by the NCBI PrimerBlast tool. On embryonic day 13 (E13) embryos show renal tubules, undifferentiated mesenchymal structures, and a small number of developing glomeruli. Maturing glomeruli are seen in post‐hatch day 4 (D4) and day 30 (D30) kidneys, indicating that nephrogenic areas still exist in 4‐week‐old kidneys. In E13 embryos, renin mRNA measured by qPCR in the adrenal glands is equivalent to the expression in the kidneys, whereas in post‐hatch D4 and D30 maturing chicks, renal renin expressions became much higher (10–15‐hold) and relative renin expression became lower in the liver and adrenals. Also, renin expression becomes clearly visible by in situ hybridization in the juxtaglomerular (JG) area in D4 and D30, but not in E13 embryos. The results suggest that in chickens, renin evolved in both renal (presumably in arteries and arterioles) and extrarenal organs at an early stage of ontogeny and, with maturation, is more localized in the JG area of the kidney. Clear JG structures are not morphologically detectable in E13 embryos, but are visible in 4‐week‐old chicks, supporting this concept. The early appearance of the chicken angiotensin type 1 receptor agrees with renin ontogeny.

Support or Funding Information

NIH DK091330 and DK096373 to M.L.S.S.L.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Thyroid hormone supplementation dampens GABAergic inhibition of the brainstem respiratory network in newborn rat
Authors: Rousseau Jean‐Philippe , Kinkead Richard
Published: June 2021

We previously showed that thyroid hormones (THs) deficiency potentiates GABAergic inhibition in the core elements of the respiratory control circuit. To understand the underlying mechanisms, we tested the hypotheses that 1) cellular mechanisms including K+/Cl− co‐transporters contribute to the delay of GABAergic system development in TH deficient newborn rats and 2) TH supplementation following birth can reverse this enhanced inhibition. Thyroid hormone deficiency in the foetus was recreated by administrating an antithyroid susbstance (Methimazole; MMI) in drinking water of the pregnant dam at concentration of 0,02% (weight per volume; w/v) from the first day of pregnancy (gestational day 1; GD1) to the day of experiment with the newborn. TH supplementation was performed by injecting newborn rats (1 day old) intraperitoneally with Levothyroxine (L‐T4). Experiments were done on Sprague Dawley rats aged of 4 days. Protein levels of newborn co‐transporters were evaluated by western blot analysis. Each brainstem lysate samples were migrated on SDS acrylamide gel under denaturing conditions. Gel was then transferred on nitrocellulose membrane and blocked in 5% non‐fat dry milk in TBS tween. Membranes were incubated overnight with primary antibody for NKCC1 (Cell signaling) or KCC2 (Cell signaling) followed by 1h exposure to secondary antibody (Licor IRDye 800CW). Fictive breathing was measured by extracting the brainstem with a part of the spinal cord and placing it in a chamber where it was superfused with an artificial cerebrospinal fluid (aCSF). The output signal from the respiratory network was recorded by a suction electrode placed on the fourth ventral root representing the inspiratory signal sent to the diaphragm via the phrenic nerve. Brainstems were then exposed to GABAA receptor agonist (muscimol) or antagonist (bicuculline) for 20 minutes and respiratory frequency response was observed. Data show that NKCC1 and KCC2 protein expressions were similar between MMI‐treated and control groups (MMI vs Control: NKCC1 p=0.5260; KCC2 p=0.3309), but L‐T4 supplementation in TH deficient pups increased both co‐transporters protein expression (MMI/L‐T4 vs MMI: NKCC1 p=0.0044; KCC2 p<0.0001). In agreement with these results, L‐T4 supplementation decreased respiratory frequency response to muscimol in MMI‐treated pups (MMI/L‐T4 vs MMI: p<0.0001). This suggests the involvement of different mechanisms in the potentiation of GABAergic inhibition by TH deficiency with a specific action of TH supplementation on GABAergic system development. These results provide new hypotheses regarding the origins of respiratory disorders of the newborn involving reduced respiratory drive such as apnea of prematurity.

Support or Funding Information

Supported by NSERC

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