bluuebunny/crossref_metadata_2025 huggingface dataset:
Insulin‐induced hypoglycemia directly affects the cerebral microvasculature in vivo
Authors: Evans Wesley R , Sakamuri Siva V. P. , Sperling Jared A. , Sure Venkata N. , Busija David W. , Mostany Ricardo , Katakam Prasad V. G.
Published: June 2021

Objective

Insulin therapy for patients with diabetes mellitus (DM) carries the risk for acute hypoglycemia (HG). Evidence from human and animal studies has suggested a role for HG in the exacerbation of cardiovascular dysfunction accompanying DM. Specifically, animal studies have shown that recurrent HG promotes increased ischemic brain injury. Furthermore, HG has been shown to affect mitochondrial function in cultured endothelial cells. Therefore, we hypothesized that acute insulin‐induced HG directly affects the cerebral microvascular function in vivo.

Methods

Wild type C57Bl/6 mice were prepared for long term two‐photon microscopy by removing a 4mm diameter section of bone over the somatosensory cortex which was then sealed with a glass coverslip held in place with cyanoacrylate and dental acrylic. A custom titanium bar was added to the preparation for head fixation during imaging. During imaging sessions, the cerebral vasculature was visualized using FITC‐dextran 40kDa. Mice were imaged under hypoglycemia (63.2 +/− 8.2 mg/dL by imaging start) using 1–2 U/kg of Humulin‐R. Microvessels approximately 3–5μm in diameter were measured for diameter changes using ImageJ. Blood flow through cerebral microvessels was assayed using line scans over the vasculature to determine red blood cell (RBC) traffic and speed. Fluorescence intensity was also measured in ImageJ to determine any changes in BBB permeability.

Results

Acute hypoglycemia induces a vasodilatory effect in cerebral microvasculature (diameter increased by 10.0 +/− 1.7 %, N=7 mice, n=89 microvessels, vs. 1.751 +/− 1.0 % N=6 mice, n=134 microvessels, in saline controls, p = .0007). However, blood flow was not changed between groups (149.0 +/− 7.4 vs. 167.6 +/− 11.3 RBC/sec and 0.979 +/− 0.060 vs. 1.052 +/− 0.068 μm/ms). Additionally, acute hypoglycemia caused no noticeable changes in the permeability of the BBB indicated by the extravasation of FITC‐dextran.

Conclusions

Our data show that acute HG causes noticeable changes in the in vivo cerebral microvasculature, however, we did not note any changes in blood flow, potentially due to cerebral auto regulation. We therefore conclude that insulin‐induced HG causes noticeable direct effects on the cerebral vasculature that may play a role in cerebro vascular impairments in DM.

Support or Funding Information

National Institute of Health: National Institute of General Medical Sciences, National Institute of Aging, and National Institute of Neurological Disorders and Stroke (Mostany: R01AG049821; Katakam: R01NS094834).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Vascular‐cognitive Impairment after Chronic Experimental High‐thoracic Spinal Cord Injury
Authors: Jia Mengyao , Sachdeva Rahul , Wang Shaoxun , Yung Andrew , Zheng Mei Mu Zi , Lee Amanda HX , Leong Sarah , Kozlowski Piotr , Fan Fan , Roman Richard J. , Phillips Aaron A , Krassioukov Andrei V
Published: June 2021

Introduction

Cognitive impairment is present in 64% individuals with spinal cord injury (SCI), affecting their attention, memory, learning and studying abilities, which are essential for post‐injury rehabilitation and possible transition into community. Previous studies from our group have reported the presence of vascular‐cognitive impairment in SCI individuals. However, a direct link between SCI‐associated vascular dysfunction and cognitive deficits hasn't been established.

Objective

To designing a pre‐clinical model to investigate cardiovascular, cerebrovascular, and cognitive function following chronic high‐thoracic SCI.

Methods

Twenty‐eight male Wistar rats were assigned to uninjured group (CON, n=14) and T3‐level spinal transection group (SCI, n=14). Fourteen weeks after injury, cognitive function and cerebral blood flow from both group were evaluated using novel object recognition test and magnetic resonance imaging (MRI) respectively. Moreover, in vivo and in vitro physiological assessments, as well as histological assessment in cerebral vasculature were conducted.

Results

Our animal model demonstrates autonomic disreflexia (AD) event (41.860 mmHg increase in systolic blood pressure) induced by colorectal distension, clinically relevant to unstable blood pressure following SCI. We conclude that chronic high‐thoracic SCI leads to 1) short‐memory loss (p=0.0225), 2) cerebral hypoperfusion (32% reduction in baseline cerebral blood flow, p=0.0277) and 3) cerebrovascular dysfunctions, including endothelial dysfunction associated with reduced endothelial TRPV 4 expression, and 70% increased collagen I deposition.

Conclusion

This study provides evidence that vascular‐cognitive impairment occurs at chronic stage of SCI and highlighting TRPV 4 as a potential therapeutic target to improve post‐injury cognitive and cerebrovascular health.

Support or Funding Information

Canadian Institute of Health Research, Heart and Stroke Foundation of Canada

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 Fat Diet Consumption and its Association with Parenchymal Arteriole Structure and Cognition
Authors: Abolibdeh Bana , Laimon‐Thomson Erinn , Ahmad Amna , Diaz‐Otero Janice M. , Jackson William F. , Dorrance Anne M.
Published: June 2021

Obesity has been identified as a major risk factor for the development of vascular cognitive impairment with dementia, which is a form of dementia with a vascular origin. Early onset obesity increases the risk of cognitive impairment and sets individuals on a path of cognitive decline that is associated with cerebral hypoperfusion. The parenchymal arterioles (PAs) link the pial arteries to the microcirculation and they form a bottleneck in the perfusion of the microcirculation. Alterations in the structure of PAs could reduce cerebral blood flow and lead to cognitive decline. In this study, we hypothesized that a high fat (HF) diet would lead to a decline in cognition and inward remodeling of PAs. 3‐week‐old male and female Sprague Dawley rats were fed a HF or control diet for 21 weeks. Data are presented as the mean ± SEM, HF vs Control, n=3–4 in each group. At euthanasia, the HF groups weighed more than the controls (Male: 577 ± 68.9vs 450.8 ±18.8g, p=0.0637, Female: 301.3 ±12.0vs 257.3 ± 15.9g, p=0.0351). The HF fed rats had significantly higher abdominal fat weight in both males and females (Male: 20.3± 4.79 vs 7.02 ±1.32g, p<0.05, Females: 11.5 ± 2.02vs 4.05±1.31g, p<0.05). The HF males had significantly elevated fasting blood glucose of 188± 10.8 vs 150.3 ± 8.8mmol/l, p=0.0348while blood glucose was unchanged in the females; 134.5 ± 11.87 vs 129.5 ± 14.5mmol/l, p=0.750. PAs were collected and their structure was assessed using pressure myography under Ca+2free conditions and zero flow. The change in outer, lumen diameter and wall thickness of PAs from HF rats was expressed as a % of the control. In males, a decrease of 35.3± 5.1% in the outer diameter, a decrease of 24 ± 10.3% in the lumen diameter, and a decrease of 58.5 ± 5.9% in the wall thickness was observed. In the females, a decrease of 26.4 ± 8.1% in the outer diameter, a decrease of 36.2 ± 7.8% in the lumen diameter, and an increase of 25± 20% in wall thickness was observed. Cognitive function was assessed using the novel object recognition test. There was no significant difference observed in the % novel object exploration in either group (Male: 36.7 ± 6.34 vs 32.4 ± 1.63%, p=0.0792, Females: 44.8 ± 4.28 vs 45.4 ± 4.35%, p=0.968). Preliminary studies suggest that HF diet alters PA structure without affecting cognition. Interestingly, a sex difference was observed in the effects of HF feeding on wall thickness which was reduced in males and increased in females. This suggests the mechanisms responsible for artery remodeling may differ between sexes.

Support or Funding Information

R01‐HL‐137694‐01

T32: 5T32GM092715‐08

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Role of HMGB1 Protein in Experimental Myocardial Infarction
Authors: Cebova Martina , Barta Andrej , Kosutova Michaela , Pechanova Olga
Published: June 2021

Introduction

Myocardial infarction (MI) results from a reduction in coronary blood flow which is extensive enough to render the oxygen supply to myocardial tissues insufficient. MI remains a leading cause of morbidity and mortality among all cardiovascular diseases over the world. High mobility group box 1 (HMGB1) is a non‐histone chromosomal protein with multiple cardioprotective effects. The aim of the study was to evaluate the effects of HMGB1 protein on biochemical and morphological parameters after experimental MI.

Methods

12‐week‐old male WKY rats used for the study were divided into following groups: shame operated WKY without MI, WKY with MI, WKY + IM+ anti‐HMGB1 protein. In vivo model of experimental MI was induced by ligation of the left descending coronary artery and lasted 20 min. Before reperfusion anti‐HMGB1 protein was administrated i.v. Animals survived 7 days after MI. Nitric oxide synthase (NOS) activity was determined by conversion of 3[H] Arginine to 3[H] Citrulline in the aorta and ischemic, border and non‐ischemic region of the heart. NFκB expression was determined by Western blot. For morphological parameters, the hearts were excised and used for TTC‐staining procedure. Cytokine levels were investigated using the Bio‐Plex Pro Cytokine kit in the plasma. Concentration of CD was measured spectrophotometrically.

Results

Anti‐HMGB1 protein increased NOS activity in both ischemic and border part of the heart, as well as in the aorta, on the other hand NOS activity did not change in non‐ischemic part of the heart. The protein administration significantly decreased NFκB expression in MI part of the heart, as well as TNF‐alpha and IL‐6 level in plasma. Simultaneously, anti HMGB1 protein decreased MI part as well as border region of the heart.

Discussion

Considering the results, HMGB1 protein is a promising molecule for reduction the negative effects of the myocardium infarction, as well as a promising agent for the treatment of cardiovascular diseases.

Support or Funding Information

Supported by: VEGA 2/0170/17, APVV‐14‐0932

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Aortic Stiffness Increases More in the Abdominal Than the Thoracic Aorta in Aging Female Monkeys
Authors: Babici Denis , Kudej Raymond , McNulty Tara McNulty , Zhang Jie , Vatner Dorothy , Vatner Stephen
Published: June 2021

Most experimental studies on vascular stiffness in aging females have been conducted in rodents. However, the lifespan of rodents is only 2–3 years, limiting clinical relevance to humans, and they do not go through menopause, making it difficult to translate the data to aging women. The hypothesis of this investigation was that this topic would be more relevant in aging non‐human primates, as their lifespan is over 30 years and they do go through menopause. Accordingly, the goal of this investigation was to compare aortic stiffness in young adult (6±1 years old) and old (24±1 years old) female macaques. An additional unique feature was chronically implanting aortic pressure and diameter transducers to permit the study of direct and continuous measurements of aortic stiffness in conscious monkeys after full recovery from surgery. Another unique feature was to examine aortic stiffness in both the thoracic aorta (TA) and the abdominal aorta (AA). Aortic stiffness (β) was calculated as systolic pressure/diastolic pressure)/aortic strain. Aortic stiffness increased more, p<0.05, in both the TA (49%) and AA (71%) in old vs young female monkeys. The greatest increases in aortic stiffness in the old female monkeys was in the AA, as reflected by a 42% greater increase in the AA than the TA. These differences were confirmed histologically measuring collagen and elastin density and disarray. Whereas collagen density increased and elastin density decreased more in old vs young monkeys, the greatest differences were observed in collagen and elastin disarray. For example, elastin disarray increased more in the AA than the TA, and more in old vs young monkeys, e.g., there was a 48% greater increase, p<0.05, in the TA elastin disarray in old vs young monkeys. Thus, aortic stiffness increases more in old vs young females, with larger increases in the abdominal vs the thoracic aorta, with the mechanism involving changes in collagen and elastin density, but more importantly, increases in collagen and elastin disarray.

Support or Funding Information

Funding information: NIH R01 HL102472

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Intact DNA Repair in Differentiated Cardiomyocytes is Essential for Maintaining Cardiac Function in Response to Physiological Stimulus
Authors: de Boer Martine , te Lintel Hekkert Maaike , Krabbendam‐Peters Ilona , Blonden Lau A. , Hoeijmakers Jan H.J. , Duncker Dirk J.
Published: June 2021

Introduction

DNA in every cell is continuously damaged and DNA repair mechanisms are essential for protection against DNA damage‐induced aging‐related diseases. Evidence indicates that DNA damage is associated with heart failure. We have shown that unrepaired endogenously generated DNA damage drives the early onset of progressive heart failure (de Boer et al. Cardiovasc Res, 2018;114:S105). Here we studied the effects of a physiological stimulus on cardiac function in a mouse model with deficient DNA repair.

Methods

To increase the burden of spontaneous DNA damage, we generated mice with cardiomyocyte‐restricted inactivation of DNA repair endonuclease XPG (αMHC‐Xpgc/−). To induce physiological left ventricular (LV) hypertrophy, mice were exposed to 11 weeks of voluntary wheel running. Subsequently, LV geometry, function and structure were studied at age 16 weeks.

Results

Cardiomyocyte‐restricted inactivation of Xpg resulted in systolic as well as diastolic LV dysfunction, demonstrated by decreases in fractional shortening, LVdP/dtP40 and LVdP/dtmin and increases in LV end‐diastolic lumen diameter (LVEDD) and relaxation time constant tau compared to WT (Table). In addition, expression level of hypertrophy maker gene β‐myosin heavy chain (β‐MHC) was elevated. Physical activity has been shown to be beneficial for maintaining and improving cardiac function in mice after myocardial infarction (de Waard et al. Circ Res, 2007;100:1097). In contrast, exercise failed to ameliorate LV remodeling and dysfunction in αMHC‐Xpgc/−, as it produced further increases in LVEDD, tau and β‐MHC compared to sedentary αMHC‐Xpgc/− (Table). Moreover, myocardial collagen content and the number of γH2A. X positive nuclei, a marker for DNA damage, were increased, suggesting that αMHC‐Xpgc/− showed increased susceptibility to exercise.

Conclusion

Cardiomyocyte‐restricted loss of DNA repair protein Xpg increases cardiac vulnerability to develop heart failure in response to exercise training. These findings underscore the importance of genomic stability for maintenance of cardiac function, not only during basal conditions, but also in response to a physiological stimulus.

Support or Funding Information

Supported by a NHF Grant 2007B024 and CVON‐ARENA (CVON2011‐11).

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 Effect of Cocoa Flavanols and Metabolites on β‐cell Proliferation and Survival
Authors: Austin Matthew C. , Smyth Brooke J. , Manwaring Lauren P. , López G. Moroni , Ross Mimi T. , Tessem Jeffery Sivert
Published: June 2021

Currently, an estimated 30.3 million Americans have diabetes, and experts predict 54.9 million Americans will have diabetes by 2030. The increasing prevalence of Type 2 diabetes (T2D) accounts for much of this expected growth. T2D is characterized by insulin resistance, which eventually leads to a reduction in functional β‐cell mass. Thus, treatments that increase β‐cell proliferation, survival, and function have the potential to reverse the effects of diabetes. One treatment that has shown promise is the use of dietary cocoa flavanols. These compounds have shown the ability to prevent the onset of diabetes in mice. Furthermore, a recent study conducted by our lab demonstrated that monomeric cocoa flavanols improved insulin secretion by increasing mitochondrial respiration. In addition to stimulating insulin secretion, we hypothesize that cocoa flavanols may also confer antidiabetic effects by promoting β‐cell proliferation and protecting β‐cells from lipotoxicity‐mediated cell death. To that end, we present data that shows the effect of epicatechin (monomeric flavanol), oligomeric, and polymeric cocoa flavanols on β‐cell proliferation and survival. Our results demonstrated that epicatechin enhances β‐cell proliferation. This finding is important because only monomeric flavanols have been found at significant levels in circulation. Notably, several gut bacteria‐derived cocoa metabolites have also been observed and identified. Consequently, we tested the effects of several cocoa metabolites on β‐cell proliferation and survival as well. We found that the cocoa metabolite hippuric acid, also enhances β‐cell proliferation. Additionally, we suggest a mechanism for the observed increase in proliferation caused by epicatechin and hippuric acid. These findings strengthen the growing body of evidence that dietary cocoa flavanols can ameliorate the effects of T2D.

Support or Funding Information

Diabetes Action Research and Education Foundation grant #475 to JST

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Testing for epigenetic effects caused by high and low sugar diets in Drosophila melanogaster
Authors: Rujchanarong Denys , Carter Ashley
Published: June 2021

Obesity is a major health problem and has been linked to a variety of factors including prenatal and juvenile nutritional environment. Nutritional environmental effects have been shown to have epigenetic effects in humans, mice, and Drosophila melanogaster. However, the degree to which a high‐sucrose diet influences obesity and has an epigenetic impact on offspring has not been as thoroughly investigated in males as in females. We therefore examined the effects of control, low‐sucrose, and high‐sucrose diets on both maternal and paternal obesity and epigenetic effects in the male and female members of the F1 and F2 generations. This study demonstrates that variation in sucrose induced changes in parental and offspring fecundity and size.

Support or Funding Information

This research was supported by the National Institute of General Medical Sciences of the National Institutes of Health under Award Numbers; 8UL1GM118979‐02; 8TL4GM118980‐02; 8RL5GM118978‐02. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Health.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Improving the Efficiency of Mitochondrial Capacity Measurements Using Near Infrared Spectroscopy
Authors: Beard Samuel J , Benefield Madison , Das Indrajit R , McCully Kevin K
Published: June 2021

Near Infrared Spectroscopy (NIRS) has been used to noninvasively measure muscle mitochondrial capacity. Previous protocols have required 2 tests and up to 50 cuff inflations.

PURPOSE

Develop a new protocol for testing mitochondrial capacity that decreases the number of ischemic cuffs, increases comfort for participants, and improves curve fitting of the data, all while retaining reliability of the test.

METHODS

The forearm flexor muscles of sixteen young, healthy individuals were tested (23 ± 4.1 years). A resting metabolism value was collected after 5 min of complete rest before and after the test. The test involved 4 sets of 6 ischemic cuff inflations, preceded by 30s of electrically induced twitch contractions. Analysis was performed on mitochondrial metabolic rates using a customized MATLAB program.

RESULTS

The post‐test resting metabolism values were higher than the pre‐test resting values (−0.038 ± 0.02, −0.018 ± 0.01, optical density units P<0.01). There was no significant difference in the mitochondrial capacity for the four sets (1.50 ± 0.51, 1.42 ± 0.54, 1.26 ± 0.41, 1.29 ± 0.47, P=0.76).

CONCLUSION

The main finding of this study is that a test of mitochondrial capacity using four sets of 6 cuffs can be performed in less time (t ≈ 25 min) than two sets of 22 cuffs (t ≈ 45 min). While the use of a post‐test resting metabolism value did slightly lengthen the time needed to complete the study in relation to using the pre‐test value, this value appeared to be more accurate than using the pre‐test resting metabolism. The use of the post‐test resting values provided lower residuals and better agreement with previous data on the forearm muscles. Improved data collection can enhance the usefulness of NIRS based measurements of mitochondrial capacity.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Contribution of Changes in Body Composition and Adaptive Thermogenesis to the Decline in Resting Metabolic Rate During Prolonged Calorie‐Restricted Weight Loss
Authors: Fox Darius M , Martin Alexandra R , Murphy Chaise A , Koehler Karsten
Published: June 2021

In the United States, 2 out of 3 adults are overweight or obese. To lose weight, individuals engage in a variety of dietary and exercise interventions. Despite successful weight loss initially, weight loss is typically less than expected and most individuals regain weight. Both phenomena have been linked to a reduction in resting metabolic rate (RMR) secondary to weight loss.

Objective

To characterize the independent contributions of changes in body composition, the major predictor of RMR, and adaptive thermogenesis to the observed decline in RMR associated with weight loss. We predict that changes in fat‐free mass and adaptive thermogenesis will both contribute to RMR decline.

Methods

Secondary data analysis was conducted on a publically available data set from CALERIE (Comprehensive Assessment of Long‐term Effects of Reducing Intake of Energy), a 2‐year observational calorie restriction study. CALERIE data used for the present analysis examined changes in RMR, body composition, and metabolic hormones over 12 months of 25% calorie restriction in 117 non‐obese (BMI between 22–27.9 kg/m2) men and women with complete data. Changes in RMR were compared between quartiles based on loss of body weight, fat‐free mass, and fat mass. Adaptive thermogenesis was quantified as the reduction in RMR that exceeded the reduction in RMR predicted from changes in organ mass, which was assessed by Dual‐energy X‐ray absorptiometry.

Results

After 12 months, mean weight loss was 7.9 ± 0.3 kg (−10.9 ± 0.4%, p<0.001 vs. baseline), and RMR declined by 101 ± 11 kcal/d (−6.8 ± 0.8%, p<0.001 vs. baseline). Individuals who lost the most weight (Q1ΔBW) demonstrated a greater RMR decline than individuals who lost the least weight (Q4ΔBW, p<0.01). The change in RMR did not differ between quartiles based on fat free mass loss (p=0.15), but it was positively associated with the amount of fat loss (p=0.03). In addition, participants who lost the greatest amount of fat mass (Q1ΔFM) exhibited a more pronounced adaptive thermogenic effect (−79 ± 19 kcal/d) than participants with the least amount of fat loss (Q4ΔFM; −10 ± 26 kcal/d, p<0.05 vs. Q1ΔFM). Adaptive thermogenesis was correlated with declines in leptin (r=0.27, p<0.01), T3 (r=0.19, p < 0.05), and insulin (r=0.25, p<0.05).

Conclusions

During weight loss, the loss of fat mass and adaptive thermogenesis appear to be stronger predictors of RMR decline when compared to the loss of fat‐free mass.

Support or Funding Information

This work was funded in part by the University of Nebraska‐Lincoln McNair Scholars Program and the Undergraduate Creative Activities and Research Experience.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Alpha Arrestin Domain Containing 2 and Alpha Arrestin Domain Containing 3 Expression is Reduced in Skeletal Muscle by Anabolic Stimuli and Increased by Catabolic Stimuli
Authors: Gordon Bradley Scott , Rossetti Michael L , Kimball Scot R
Published: June 2021

Skeletal muscle is a highly plastic organ capable of increasing or decreasing in size depending upon the stimuli placed upon it. While this is known, the molecular factors that contribute to changes in skeletal muscle mass under anabolic and catabolic conditions remain ill defined. As such, the objective here was to identify novel genes that likely contribute to changes in skeletal muscle mass following anabolic or catabolic stimuli. For the initial identification of such genes, male mice were fasted overnight to induce a catabolic state in the skeletal muscle. The next morning, half of the mice were allowed to refeed for 30 minutes to effectively impart an anabolic stimulus on the skeletal muscle. Using an unbiased microarray approach and subsequent qRT‐PCR validation, the refeeding stimulus resulted in a significant reduction in the mRNA expression of Alpha Arrestin Domain Containing 2 (Arrdc2) and Alpha Arresting Domain Containing 3 (Arrdc3) in the tibialis anterior (TA) muscle. The reduction in Arrdc2 and Arrdc3 mRNA expression was not limited to nutrient consumption or the TA muscle as mechanical overload also reduced Arrdc2 and Arrdc3 expression in the TA and plantaris muscles. Moreover, the combination of nutrient consumption with mechanical overload had a synergistic effect on reducing Arrdc2 and Arrdc3 expression. Interestingly, these reductions in Arrdc2 and Arrdc3 expression following mechanical overload occurred even when signaling through the mechanistic target of rapamycin in complex 1 (mTORC1) growth pathway was disrupted. On the converse, Arrdc2 and Arrdc3 mRNA expression was increased in the muscle by catabolic stimuli other than fasting, which included androgen deprivation and the metabolic stress imposed by an acute bout of aerobic exercise. The divergent changes in Arrdc2 and Arrdc3 mRNA expression in the skeletal muscle following anabolic and catabolic stimuli were consistently related to the corresponding changes in markers of autophagy activation. While Arrdc2 and Arrdc3 expression showed consistent and divergent changes in expression under these conditions, no consistent changes in expression of other members of the Alpha Arresting Domain Containing family of genes were observed. In all, these data suggest changes in Arrdc2 and Arrdc3 expression may contribute to the regulation of skeletal muscle mass following anabolic and catabolic stimuli by altering autophagy activation.

Support or Funding Information

NIH‐DK15658 (SRK) and FSU Council on Research and Creativity (BSG)

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 TNF Receptor Associated Factor 3 Interacting Protein 3 (Traf3ip3) in Skeletal Muscle
Authors: Golliher Ciara , DaSilva Anjelica , Waddell David
Published: June 2021

Skeletal muscle atrophy is a physiological condition that results in decreased muscle size and strength and occurs in response to immobilization, denervation, spinal cord injury and aging. 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 in order to identify novel neurogenic atrophy‐induced genes. The microarray data revealed that TNF Receptor Associated Factor 3 Interacting Protein 3 (Traf3ip3) is expressed in skeletal muscle and is induced in response to denervation. To confirm that Traf3ip3 is expressed in muscle cells, we cloned the Traf3ip3 cDNA from cultured muscle cells and performed quantitative PCR (qPCR) to assess expression levels in both proliferating and differentiated muscle cells. The qPCR results demonstrated that Traf3ip3 expression levels are relatively low in proliferating myoblasts but show dramatically elevated expression in differentiated myotubes. To characterize the transcriptional regulation of Traf3ip3, fragments of the proximal promoter located immediately upstream of the start of transcription were cloned and fused to a reporter gene. The reporter plasmids were then transfected into C2C12 mouse muscle cells in combination with myogenic regulatory factor (MRF) expression plasmids, which resulted in differential effects on reporter gene activity. The discovery that Traf3ip3 is expressed in muscle combined with the observation that this gene is induced in response to neurogenic atrophy helps further our understanding of the molecular genetic events of skeletal 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.
Oral Ketone Supplementation Acutely Increases Markers of NLRP3 Inflammasome Activation in Human Monocytes
Authors: Neudorf Helena , Durrer Cody , Myette‐Cote Etienne , Makins Caitlyn , O'Malley Trevor , Little Jonathan P.
Published: June 2021

Recent cell culture studies indicate that the ketone body β‐hydroxybutyrate (β‐OHB) directly inhibits the NLRP3 inflammasome, which plays an important role in regulating inflammation. However, there is limited direct evidence demonstrating this effect in humans.

Objectives

To determine the effects of acutely raising blood β‐OHB on NLRP3 inflammasome activation in healthy humans.

Methods

We conducted two randomized double‐blind placebo‐controlled experiments wherein participants' blood β‐OHB levels were directly elevated by ingesting supplements containing ketone salts (0.3 g β‐OHB/kg; Study 1, N = 10 males) or ketone monoesters (0.482 g β‐OHB/kg; Study 2, N = 20, 50% females). Blood samples were obtained in the fasted state and 30‐minutes following ingestion of ketones or placebo. Markers of NLRP3 inflammasome activation included monocyte caspase‐1 (flow cytometry) and interleukin (IL)‐1β secretion (ELISA) in LPS‐stimulated whole blood cultures, and IL1B and NLRP3 mRNA expression (qPCR) from whole blood.

Results

Blood β‐OHB was significantly raised from baseline following both ketone salt (0.2 ± 0.1 mM to 0.9 ± 0.2 mM; P < 0.001) and ketone monoester (0.2 ± 0.1 mM to 3.2 ± 0.6 mM; P < 0.001) ingestion with no change in placebo. Caspase‐1 activation increased 30 minutes after consuming both ketone salt (condition X time interaction, P = 0.012) and ketone monoester (condition X time interaction, P = 0.016) supplements but not placebo. IL‐1β secretion from stimulated whole blood cultures was increased following ketone monoester consumption (9.1 ± 7.6 pg/mL to 10.9 ± 6.5 pg/mL; main effect of condition, P = 0.024) with no change in placebo. There were no significant effects of ketone supplementation on IL1B and NLRP3 mRNA expression.

Conclusions

Measures of NLRP3 activation increased when blood β‐OHB was acutely elevated using ketone supplements, suggesting that artificially increasing β‐OHB may have unintended metabolic effects that augment activation of circulating immune cells.

Support or Funding Information

This study was funded by a Natural Sciences and Engineering Research Council (NSERC) of Canada Discovery Grant (Grant number 435807). JPL is supported by a Canadian Institutes of Health Research (CIHR) New Investigator Salary Award (MSH‐141980) and a Michael Smith Foundation for Health Research (MSFHR) Scholar Award (16890). H.N. was supported by a NSERC Undergraduate Student Research 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.
THE PRETERM INFANT GUT MICROBIOME, HUMAN MILK VOLUME AND IMMUNOBIOLOGY, AND GROWTH
Authors: Groer Maureen , Dutra Samia Valeria , Miller Elizabeth , Yee Alyson , Gilbert Jack
Published: June 2021

We conducted a study of gut microbiome in very low birth weight (VLBW) infants along with measures of milk feedings (type and volume) and milk sIgA, cytokines and chemokines for six weeks after admission in 78 infants. Stools were collected weekly, and human milk collected daily and pooled weekly for a panel of immune markers. Mothers of these infants gave informed consent and the study was approved by the university IRB. Mean levels of sIgA, EGF, MIP1α, IP10, MCP1, IL‐8, IL‐4, IL‐6, IL‐10 and TNFα were measured each week for six weeks by MagPix.4.2. Stool DNA was extracted using MoBio kits, the V3–V4 region of the 16S rRNA gene was amplified and then sequenced on an Illumina MiSeq.

These infants had a mean gestation age at birth of 28 weeks, 3 days, and a mean birth weight of 1078 Gms. The mean time to full enteral feeding was 12 days, and they were fed mothers own milk (MOM), donor milk or preterm infant formula in varying amounts. The infant stool demonstrated marked dysbosis over time, with a dominance of Gram negative Gammaproteobacteria. Mean levels of sIgA, EGF, MIP1α, IP10, MCP1, IL‐8, IL‐4, IL‐6, IL‐10 and TNFα were measured each week for six weeks. Data reported here are mean Shannon diversity, and mean number of operational taxonomic units (OTUs) over the first six weeks of admission to the NICU, the ratio of human milk volumes to total feed volumes, the mean concentrations of milk immune markers over the 6 weeks of measurement, and the relationship between growth and the microbiome in these infants.

Shannon diversity significantly increased with increasing corrected gestational age (cGA) (Multiple R2: 0.09221, p= 1.28e‐08). Adjusting for cGA during the NICU stay, the alpha diversity also showed weak but significant correlations with overall rate of weight gain (Multiple R2: 0.144, p=0.00208) and total ratio of mother's own milk (Multiple R2: 0.1097, p = 0.024918).

Over the 6 weeks of admission, the mean number of fecal OTUs was correlated with mean milk IL‐4 (pg/ml) (r=.25, p=.03), but no other milk immune markers. The time to enteral feeding was inversely correlated to the number of OTUs (r=‐.24, p=.036). Lower diversity was observed in infants with lower gestational age (t=.31, p=.006), sepsis (t=2.43, p=.017), and days on oxygen (r=.23, p=.04).

This is the first study to show that growth of VLBWs may be influenced by the microbiome in these early weeks of life. There were few relationships between specific immune markers and gut microbiome, but the amount of MOM an infant receives may partially ameliorate the dysbiosis.

Future studies are planned to investigate the growth/nutrition/microbiome relationship in VLBWs as they grow and develop into early school age.

Support or Funding Information

NIH R01NR15546

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Resolving Subtle Treatment Effects through Pharyngeal Pumping Variability Assessment in the Nematode C. elegans
Authors: Harris Michael B , Barrientos Christopher , Bui Andy , Co Mary , Gill Sunny , Lim Shelby , Ly Lily , Ortiz Brianna , Parabo Ashley , Phillips Derek , Tran Adrian , Valdez Vanessa , Vu Tien , Taylor Barbara E , Berlemont Renaud
Published: June 2021

In C. elegans, feeding is achieved through a well characterized behavior, pharyngeal pumping. This 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. Many studies evaluate pharyngeal pumping to reveal experimental results and, traditionally, this has been quantified as an occurrence frequency by determining the number of pumps observed in a given time. Although rhythmic, pharyngeal pumping is both variable and periodic, and traditional pharyngeal pumping rate assessment does not consider underlying variability of pumping behavior or the sources of this 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. The theory and practice of the WormBeat algorithm is described in a companion presentation. Here we use both traditional event‐frequency analysis and our algorithm to evaluate pharyngeal pumping. Studies are done in wild type (N2) C. elegans during pharmacological manipulations designed to alter the pace and regularity of MC and/or of the fidelity of pharyngeal neuromuscular junction. We also evaluate pharyngeal pumping in a series of mutant strains with known pumping defects. Our results illustrate that the WormBeat algorithm can identify subtle treatment effects and can identify and distinguish variation on motor neuron pacing from that produced by disruption of neuromuscular fidelity. These data support a hypothesis that underlying variability is a relevant and insightful index of functional decline in this model organism

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.
Primary Neurons from the Painted Turtle: A New Model for Comparative Neurobiology of Vertebrate Anoxia Tolerance
Authors: Riggs Claire L. , Xu Fenglian , Warren Daniel E.
Published: June 2021

The painted turtle, Chrysemys picta, is the most anoxia‐tolerant tetrapod known, surviving over 170 days without oxygen at 3°C. A key component of C. picta's anoxia tolerance is metabolic depression: ATP use is dramatically reduced in the brain, in large part by suppression of nervous activity and channel arrest. This differs from mammals, which lack the ability to enter metabolic depression and withstand anoxia. Developing new tools to understand the neurobiology of the painted turtle has the potential to provide novel insight into the biology of anoxia‐tolerant vertebrates. While nearly all studies of anoxic turtle neuron function have been conducted in cortical sheets, the isolation and subsequent culture of primary neurons, to our knowledge, has not been conducted in this species. The goal of this study was to culture primary neurons from hatchling painted turtles and to develop a functional model for studying the neurobiology of anoxia tolerance. Primary neurons were dissociated from the cerebrocortex using enzymatic treatment and mechanical trituration and cultured in neurobasal medium supplemented with FBS, Penicillin/Streptomycin, B27, and L‐glutamine. Culturing the neurons on glass coverslips coated with laminin and poly‐D‐lysine at 37°C with 5% CO2 results in high neuronal survival and growth of neurites. Isolated neurons exhibit morphologies stereotypical of normal vertebrate neurons, with neuritic processes clearly identifiable. Importantly, the isolated cells showed functional responses characteristic of neurons, including calcium transients when excitatory factors, such as high concentration of KCl, were applied. This work represents the first in vitro primary culture of neurons from anoxia‐tolerant painted turtles that show normal vertebrate neuronal morphology and function.

Support or Funding Information

This work is supported by the NSF CAREER award 1253939 to Dr. Warren and the Saint Louis University Start‐Up Fund to Dr. Xu.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Fluid‐structure interaction simulation of balance sensation in the avian lumbosacral organ
Authors: Wold Ethan , Daley Monica
Published: June 2021

The lumbosacral organ (LSO) is an enlargement of the avian spinal cord hypothesized to play a role in balance sensation. Several lines of anatomical and neurophysiological evidence suggest that the LSO is directly integrated with spinal motor circuits, independent of the vestibular system. However, no model currently exists to explain its physiological function. We hypothesized that mechanosensors may respond to differential strain in spinal ligaments. We segmented iodine‐enhanced CT scans of the quail LSO to visualize the 3D anatomy of the structure. We then utilized two‐way fluid structure interaction simulations to model possible balance sensing function. Our modeling suggests that the LSO spinal ligaments are able to sense the directionality of an applied balance perturbation in the form of differential strain patterns. Furthermore, given anatomical constraints, it is unlikely that fluid velocity alone is sufficient to cause deformation in the spinal tissue. Inertia of the fluid and soft tissue itself play significant roles in generating the ligament strain. This work is the first simulation study of the LSO in any species and provides a methodological framework for further fluid dynamics modeling of the system. Our 3D reconstruction suggests potential anatomical constraints on fluid flow and supports the ligament strain hypothesis of balance sensing function. Higher resolution simulation work, as well as experimental validation studies in live animals are needed to more precisely evaluate the hypotheses for balance sensation in the LSO.

Support or Funding Information

This work was made possible by support from the American Physiological Society and the National Science Foundation Integrative Organismal Systems Award (Award No. IOS‐1238831).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Pharmacological identification of cholinergic receptor subtypes in modulation of neural circuits in Drosophila melanogaster
Authors: Bhutto Umair Fareed , Cooper Robin
Published: June 2021

Acetylcholine (ACh) is an abundant neurotransmitter and neuromodulator in many species. In Drosophila melanogaster ACh is the neurotransmitter used in peripheral sensory neurons and is a primary excitatory neurotransmitter and neuromodulator within the central nervous system (CNS). The receptors that facilitate synaptic transmission at cholinergic synapses and beyond are divided into two broad subtypes: the ionotropic nicotinic acetylcholine receptors (nAChRs) and the metabotropic muscarinic acetylcholine receptors (mAChRs). This receptor classification is shared in both mammals and insects; however, both the pharmacological and functional characterization of these receptors within the Drosophila nervous system has lagged behind its mammalian model counterparts. In order to identify the impact of ACh receptor subtypes in regulating the performance of select neural circuits within the larval CNS, we have used a behavioral and electrophysiological approach to assess cholinergic modulation of locomotion, feeding, and sensory‐CNS‐motor (sensorimotor) circuit activity. We have exposed intact 3rd instar larvae to ACh agonists and antagonists to observe modulation of these behaviors and also expose an intact nervous system directly to solutions containing these compounds to address their influence on sensorimotor circuit efficacy. We reveal that chronic ACh exposure enhances locomotion but reduces feeding behavior and acute application excites a sensorimotor circuit. Nicotine exposure reduces activity through suspected rapid receptor desensitization. Moreover, chronic muscarine exposure reduces locomotion and feeding, but acute exposure enhances sensorimotor circuit activity. These results suggest a role for both nAChRs and mAChRs in modulating these select circuits and illuminates important pharmacological properties of cholinergic receptor subtypes in vivo.

Support or Funding Information

Funding Dept. of Biology, Kentucky Science and Engineering Foundation (KSEF‐3712‐RDE‐019) at the Kentucky Science and Technology Corporation (RLC), Ribble Scholar funds, & personal funds (RLC).

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 the Corticotropin‐releasing Factor (CRF) System in Atlantic Salmon (Salmo salar)
Authors: Lai Floriana , Royan Muhammad Rahmad , Gomes Ana Silva , Rønnestad Ivar
Published: June 2021

In contrast to most other teleosts studied to date, salmonids has undergone four whole genome duplications (WGD), commonly referred to as the Ss4R (salmonids‐specific 4th vertebrate WGD) event. Large genomic rearrangements and the restoring of the disomic chromosome inheritance in the ancient polyploidy have been crucial for the post Ss4R re‐diplodization process, leading to possible divergent functions of duplicated genes. This evolutionary genome duplication, together with the available genome sequence information for Atlantic salmon (Salmo salar), provide a unique opportunity to investigate the pivotal roles of gene diversity and functionality.

When facing variable external or internal adverse effects beyond their homeostatic state, teleosts engage a stress response through the Hypothalamic‐Pituitary–Interrenal gland (HPI) axis to restore the compromised physiological steady state and enable the animal to overcome the threat. Corticotropin‐releasing factor (CRF), CRF‐binding proteins (CRFBPs) and CRF receptors (CRFRs) are commonly used as markers for stress responsiveness. This system has been poorly explored in Atlantic salmon, thus, in this study, we aim to investigate all the CRF system players.

As for other salmonids, the Ss4R event induced the tetradiploidization in the Atlantic salmon genome leading to the several duplicated genes (paralogues) in these species. We currently investigate the crf, crfbp and crfr genes to explore the roles of the different paralogues. In silico analysis show that the Atlantic salmon genome has four crf paralogue genes distributed among chromosome (Chr)Ssa03, ChrSsa14, ChrSsa19 and ChrSsa29, two crfbp genes located in the ChrSsa01 and ChrSs11, two crfr1 paralogue genes placed in the ChrSsa03 and ChrSsa06 and two crfr2 paralogue genes in ChrSsa03 and ChrSsa14. To evaluate their function in the HPI stress response axis, we have analysed the mRNA expression of the different transcripts in different brain regions of Atlantic salmon post‐smolts. Our initial data shows that all crf transcripts are present in the hypothalamus and pituitary. However, further analysis are needed and particularly the characterization of these several transcripts under control and stressed conditions.

Support or Funding Information

Funded by the Research Council of Norway (NFR 267626 LeuSENSE).

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