bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetin is Sufficient to Accelerate Mitophagy Flux in H9c2 Cardiac Myoblast Cells
Authors: Nagaria Omar , Singh Suprit , Kabir Rizowana , Kobayashi Satoru , Kobayashi Tamayo , Liang Qiangrong
Published: June 2021

The lysosomal degradation of dysfunctional mitochondria is vital for cellular health. Although widely known for their role in oxidative phosphorylation, mitochondria also generate reactive oxygen species (ROS) that are cytotoxic. Mitochondria themselves are susceptible to ROS damage, which can render them dysfunctional and eventually lead to various modes of cell death. Therefore, to maintain a healthy population of mitochondria, it is crucial for cells to eliminate injured mitochondria through the autophagy‐lysosomal pathway, a process termed mitophagy. Previous studies have identified Kinetin (KTN) as an activator of PTEN‐induced kinase (PINK‐1), a mitochondrial kinase that is activated in response to mitochondrial damage and orchestrates downstream mitophagy processes. While KTN has been shown to induce mitophagy in human‐derived neural cells, its role in cardiomyocytes remains unknown. In the present study, we tested the ability of KTN to induce mitophagy in H9c2 cardiac myoblast cells. The cells were treated with KTN, and a subset of cells was additionally treated with lysosomal protease inhibitors: pepstatin A (pepA) and E64d. Mitochondrial fractions were isolated and the expression levels of LC3‐II (Microtubule‐associated protein 1A/1B‐light chain 3), an established marker of autophagic vesicles, were analyzed using Western blotting. Our results showed that pepA/ E64d treatment led to a much larger increase in LC3‐II levels among KTN‐treated cells relative to the vehicle‐treated cells, suggesting that KTN was sufficient to accelerate mitophagy flux in cardiomyocytes. This result was confirmed by a novel dual fluorescent mitophagy reporter. Our lab is currently investigating whether KTN can protect cardiomyocytes against stress‐induced cellular injury through upregulation of mitophagy.

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 Medium‐chain Triglyceride Diet Attenuates Weight Gain, but Does Not Affect Insulin‐stimulated Glucose Uptake in Male Rats
Authors: Brothwell Marisa J , Connolly Gavin , Sharma Naveen
Published: June 2021

Recently, there has been increased dietary consumption of medium‐chain triglycerides (MCT; triglycerides containing fatty acids chains C6:0‐C12:0) for purported ergogenic and weight loss effects. Diets high in fat are known to contribute to insulin resistance, but the impact of high MCT‐based diets on glucose uptake and insulin signaling are not well‐known. Therefore, we investigated the effect of a high‐MCT diet on insulin‐stimulated glucose uptake in rat skeletal muscle. Male Sprague‐Dawley rats, ages 7–17 months, were assigned to one of 3 isocaloric dietary groups: 1) low‐fat control group (CON; 20% protein, 70% carbohydrate, 10% fat mostly from MCT), 2) high‐fat group (HF; 20% protein, 35% carbohydrate, 45% fat mostly from lard) and 3) high‐fat MCT group (MCT; 20% protein, 35% carbohydrate, 45% fat mostly from MCTs). All rats had ad libitum access to their respective diets and water for 8 weeks. Body masses and food consumption were recorded weekly. During the terminal study, a soleus muscle from eat rat was excised, split into equal thirds, and placed in vials containing physiological buffer including 1 of 3 insulin concentrations (0, 0.6, or 30nM). Muscles were then incubated in the presence of radioisotopes to determine glucose (2‐deoxyglucose; 2‐DG) uptake. Homogenates were also used for Western blotting to assess phosphorylation and abundance of key insulin signaling proteins. The MCT group consumed the least amount of food daily and gained the least weight at the end of 8wks. We observed a main effect of insulin (p<0.05) in regards to 2‐DG uptake, but no differences associated with diet. We found similar results regarding phospho‐AktSer473. We report that a high‐fat diet consisting of MCTs will lead to less weight gain compared to a high‐fat diet consisting of lard. However, the fat source did not affect insulin‐stimulated glucose uptake in isolated muscle, suggesting that diets high in MCTs may not improve insulin sensitivity compared to high lard‐based diets despite reduced weight gain. These results imply that a diet high in MCTs may translate to greater meal satiety and better weight maintenance, compared to other high‐fat and even lower‐fat diets.

Support or Funding Information

Office of Research and Graduate Studies and the Herbert H. & Grace A Dow College of Health Profession at Central Michigan University

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effects of Nicorandil and Chronic Physical Exercise on Glycemia in Diabetic Rats Induced by Streptozotocin
Authors: Sánchez‐Duarte Elizabeth , Sánchez‐Duarte Sarai , Vera‐Delgado Karla S. , Montoya‐Pérez Rocío , Caudillo‐Cisneros Cipriana , Cordova Victor , Sánchez‐Briones Luis A. , Márquez‐Gamiño Sergio
Published: June 2021

Diabetes is a chronic metabolic disease characterized by persistent hyperglycemia caused by a decrease or deficiency of insulin secretion and/or peripheral insulin resistance. Regular physical exercise could improves glucose metabolism and insulin sensitivity, which is essential for preventing diabetic complications. Moreover, there is evidence that the opening of ATP sensitive potassium (KATP) channels contributes to cytoprotective effects under metabolic stress, therefore KATP channels could be a therapeutic target in this disease. Thus, the purpose of this study was to assess the impact of the potential effects of nicorandil (KATP channel opener) after a chronic exercise training program on levels glicemic in diabetic rats.

Male Wistar rats (23–25 days old) were randomly divided into six groups, among them: sedentary control, trained control, sedentary diabetic, trained diabetic, sedentary diabetic plus nicorandil, trained diabetic plus nicorandil. Diabetes was induced by a single streptozotocin injection (100 mg/kg body weight), animals with fasting blood glucose levels ≥ 250 mg/dL were considered as diabetic. Training comprised 8 weeks of treadmill running (30 minutes daily, 5 days/week); at week 4, nicorandil (3 mg/kg) was administered for to 4 weeks. Fasting blood glucose (FBG) level was recorded every week for 8 consecutive weeks. At the end of experimental protocol, insulin tolerance test (ITT) was evaluated in all groups, rats received a application of insulin (0.75UI/kg body weight), with blood samples drawn after 0, 30, 60, 90 and 120 min postinjection. Blood glucose response to ITT was calculated as area under the curve (AUC‐ITT) of the blood glucose excursion along 120 minutes after intra‐peritoneal insulin injection and correlated with the corresponding fasting values according to the trapezoidal method.

Treatment with nicorandil and the chronic exercise exerted remarkable effects on hyperglycemic status in diabetic rats by decreases FBG levels (47.51± 10.2 %) and inducing significant increases in the insulin sensitivity (P< 0.05) compared with sedentary diabetic rats and trained diabetic rats. Our results suggest than opening KATP channels by nicorandil mediates potential benefits the chronic physical exercise on glycemic in diabetes.

Support or Funding Information

We thank Universidad de Guanajuato, Campus León. We acknowledge the financing PRODEP (Programa para el Desarrollo Profesional Docente en Educación Superior, ESD (511‐6/18‐8876).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Sleepiness and Mortality Risk in Patients without Sleep Apnea
Authors: Lu Dongmei , St Louis Erik K. , Chahal C. Anwar , Covassin Naima , Mohamed Essa A. , Mansukhani Meghna P. , Xie Jiang , Lipford Melissa C. , Li Nanfang , Ramar Kannan , Caples Sean M. , Gay Peter C. , Olson Eric J. , Morgenthaler Timothy I. , Somers Virend K.
Published: June 2021

Background

The prevalence of excessive daytime sleepiness (EDS) in the general population is reported to be 9 to 28 percent. Various social and biological factors have been reported to contribute to the development of EDS, such as cardiovascular disease, metabolic disorders as well as socioeconomic status. Medically, EDS is associated with poorer prognosis in patients with sleep disorders. However, whether sleepiness is an independent negative prognostic indicator in patients without sleep apnea is poorly understood.

Objective

To evaluate the relationship between self‐reported excessive daytime sleepiness (assessed by Epworth Sleepiness Scale) and the risk of all‐cause mortality in patients without obstructive sleep apnea (OSA).

Methods

We performed a retrospective cohort study in a large registry of patients seen at the Mayo Clinic Center for Sleep Medicine between November 17th, 2009 and April 15th, 2017. All patients received a diagnostic polysomnography and had completed Epworth Sleepiness Scale (ESS). The primary outcome of all‐cause mortality risk was computed using the Kaplan‐Meier analysis and Cox‐proportional hazard model with age, sex, body mass index (BMI), baseline comorbidities and sleep measurements as confounders.

Results

A total of 2746 non‐OSA patients were identified. The overall median age (IQR) was computed as 53 (40, 63) with 45% of patients identifying as males. The median follow‐up time was approximately 2.3 years. In a univariate analysis, daytime sleepiness was associated with the female sex, younger age and higher BMI. No significant differences were observed in vascular related diseases between sleepy and non‐sleepy patients. EDS was not significantly associated with all‐cause mortality with an adjusted hazard ratio of 1.23 (95% CI 0.86, 1.76; p=0.257). In addition, there was no significant association of EDS and the risk of all‐cause mortality even after stratifying by sex, age and BMI in non‐OSA patients.

Conclusion

EDS is not associated with all‐cause mortality in non‐OSA patients. Further prospective studies are needed to confirm this finding.

Support or Funding Information

This research was supported by NIH HL65176 and NIH HL114024.

Kaplan–Meier survival curve of 8 years all‐cause mortality of non‐OSA patients with and without excessive daytime sleepiness (EDS) at baseline.

image

Kaplan–Meier survival curve of 8 years all‐cause mortality of non‐OSA patients with and without excessive daytime sleepiness (EDS) at baseline.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Association between type 2 diabetes mellitus risk factors with breast cancer in Mexican women
Authors: Soto‐Piña Alexandra Estela , Cardoso‐Peña Elías , de Jesús Garduño‐García Jose , Gómez‐Villanueva Ángel , López‐Chávez Emilio
Published: June 2021

Breast cancer is a neoplasic disorder in women worldwide and the comorbidity with type 2 diabetes mellitus (T2DM) is increasing. However, it is not clear how T2DM risk factors such as high waist circumference, hyperglycemia (>100 mg/dL) and dyslipidemia participate in the appearance and development of breast cancer. The aim of this study was to compare T2DM risk factors between women with and without breast cancer. This study included two groups of women 40–60 years old: the control group (n=3) included women with BIRADS 1, 2 and 3 mammograms, and the group with breast cancer (n=3) comprised women in stages I and II of breast cancer. Data were analyzed using Mann‐Whitney test. The results showed that women with breast cancer presented a non‐significant increase (p=0.40) in the mean concentration of glucose (92.7 ±8.7 mg/dL) compared to the control group (80.0 ±4.3 mg/dL). The mean percentage of glycosylated hemoglobin in women with breast cancer was 5.3 ±0.5 % and the one in the control group was 5.4 ±0.1 %. Additionally, women with breast cancer showed a wider waist circumference (98.7 ±13.2 cm) than the control participants (83.3 ±5.2cm); however, these variables were not significantly different. In summary, there were no significant differences between women with and without breast cancer in the assessed T2DM risk factors; nonetheless, there are clear trends towards altered value limits in these risk factors, therefore, further analyses increasing the sample number are required to confirm the association between T2DM risk factors with breast cancer in this population of women.

Support or Funding Information

Support provided by Universidad Autónoma del Estado de México.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effects of Modest Weight Gain On Circulating Free Fatty Acids
Authors: Pinzon Jeffer , Medina Inojosa Jose R. , Covassin Naima , Huang An , Somers Virend K. , Jensen Michael D. , Singh Prachi
Published: June 2021

Background

Increases in circulating free‐fatty acids (FFAs) contribute to obesity‐associated cardiometabolic pathology and may be considered a surrogate marker for adipose tissue dysfunction. However, alterations in FFA metabolism resulting from modest weight gain have not been previously evaluated.

Objective

Examine the changes in FFAs during modest weight gain in healthy individuals and to investigate the relationship between regional fat depots.

Study Design

We evaluated the effects of overfeeding in 8 healthy, non‐obese participants (4 men; age 29 ± 5.7 years; BMI: 25.1 ± 2.1 kg/m2). FFA concentrations were measured using liquid chromatography/mass spectrometry under fasting conditions and during oral‐glucose tolerance test (OGTT) at baseline and after 8 weeks of weight gain. Prior to the baseline and weight gain visits, subjects consumed isocaloric macro‐nutrient stable diet for three days (50% carbohydrate, 35% fat and 15% protein). Body composition and regional fat depots were assessed using dual‐energy X‐ray absorptiometry and abdominal computed tomography scans.

Results

Overfeeding was accompanied by 3.9 ± 1.6 kg weight gain (p=0.01) resulting from 2.9 ± 0.9 kg (p=0.01) increase in fat mass and 1.0 ± 0.9 kg (p=0.04) increase in fat‐free mass. Compared to baseline, fasting FFA (439 ± 162 μM vs. 368 ± 123 μM, p=0.55) and area under the curve (AUC) for FFA during OGTT (23319 ± 11686 μM. min−1 vs. 20495 ± 4847 μM.min−1, p=0.55) did not change with weight gain. However, at 120 min. of the OGTT FFA were significantly greater after weight gain (60 ± 18 μM vs. 77 ± 34 μM, p=0.04). We found a negative relationship between relative changes in visceral fat area and FFA at 120 min of glucose challenge (rho=−0.76, p=0.03). Furthermore, relative changes in fasting FFA and AUC for FFA during OGTT with weight gain were associated with baseline total fat mass (fasting FFA: rho=0.76, p=0.03; AUC FFA: rho=0.81; p=0.02) and baseline abdominal fat area (fasting FFA: rho=0.76, p=0.03; AUC FFA: rho=0.79; p=0.02).

Conclusions

Modest weight gain does not alter fasting FFA or overall FFA response to oral glucose challenge. However, our data suggest development of early stages of adipose tissue insulin resistance which is apparent via lesser suppression of FFA at 120 min. of OGTT. Furthermore, the relationships between fasting FFA, AUC‐FFA, and baseline fat mass suggest that individuals with high baseline adiposity may be more susceptible to develop adipose tissue insulin resistance with weight gain.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Inflammatory Cytokines and Blood Pressure after Renal Denervation in 2‐Kidney, 1‐Clip Hypertensive Rats
Authors: Lauar Mariana Ruiz , Van Helden Dusty , Banek Christopher T , Evans Louise C , Menani Jose Vanderlei , Osborn John W
Published: June 2021

Hypertension (HTN) is a multifactorial disease that affects one third of the population of western countries. Although 95% of cases are of unknown origin (i.e., primary HTN), it is well established that renal ischemia results in secondary renovascular HTN. Experimental renovascular HTN is induced in rats by placing a silver clip on the left renal artery creating a stenosis, which decreases renal perfusion pressure and increases renin release from the clipped kidney (2K1C‐HTN). Previous studies indicate a role of renal nerves in 2K1C‐HTN since renal denervation (RDN) attenuates HTN in 2K1C‐rats. Moreover, activation of the sympathetic nervous system in this model is associated with inflammation in the hypothalamus, a key site for regulation of sympathetic activity that also receives input from afferent renal nerves. In the present study, we tested the hypothesis that renal nerves modulate the levels of hypothalamic proinflammatory cytokines and mean arterial pressure (MAP) in 2K1C rats. Male Sprague‐Dawley rats (150–180 g, n=2–4/group) received a clip on the left renal artery to generate 2K1C HTN and were instrumented with telemeters to measure MAP. Four weeks later rats underwent RDN (2K1C‐RDN) or sham (2K1C‐sham) surgery of the clipped kidney and MAP measurement continued for the following 2 weeks. Rats were then euthanized and brains quickly removed for subsequent measurement of hypothalamic cytokine content. Preliminary data demonstrated that MAP was lower 2K1C‐RDN (157±20 mmHg) than 2K1C‐sham (175±7 mmHg) rats. RDN also tended to decrease hypothalamic cytokine content. IL‐1β was 25±3 pg/mg in 2K1C‐RDN compared to 151±66 pg/mg in 2K1C‐sham rats. IL‐6 content was 24±19 pg/mg in 2K1C‐RDN vs. 39±0.5 pg/mg in 2K1C‐sham rats. The results suggest that RDN may decrease hypothalamic inflammation in 2K1C hypertensive rats and this may be one mechanism by which RDN decreases MAP in this model.

Support or Funding Information

FAPESP (2018/11221‐1), PROPE/FUNDUNESP and NIH R01 HL116476.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Protective Role of Vascular Smooth Muscle RhoBTB1 in Hypertension
Authors: Fang Shi , Mukohda Masashi , Wu Jing , Agbor Larry N. , Nair Anand R. , Ibeawuchi Stella‐Rita , Hu Chunyan , Liu Xuebo , Lu Ko‐ting , Guo Deng‐Fu , Davis Debbie , Keen Henry L. , Quelle Fredrick W. , Sigmund Curt D.
Published: June 2021

RhoBTB1 is an atypical GTPase, which is associated with human hypertension according to a genome‐wide association study. However, the physiological and molecular role of RhoBTB1 is not well understood. Previously, we showed that aortic RhoBTB1 is downregulated in two hypertension models including systemic angiotensin II (Ang II) infusion and vascular smooth muscle (VSM) specific expression of human hypertension causing dominant negative PPAR gamma mutant P467L (S‐P467L). To achieve RhoBTB1 genetic complementation, we generated mice with VSM specific, tamoxifen inducible RhoBTB1 (S‐RhoBTB1) expression. Previous studies showed that S‐RhoBTB1 mice are resistant to Ang II‐induced hypertension. In the current study, we are investigating whether restoration of RhoBTB1 expression is sufficient to reverse established Ang II‐induced hypertension. S‐RhoBTB1 mice received systemic Ang II‐infusion (490ng/kg/min) for two weeks before tamoxifen injection. However, S‐RhoBTB1 did not reverse Ang II‐induced elevated blood pressure. Aorta and carotid artery still exhibited impaired vasodilation to acetylcholine and sodium nitroprusside. Pulse wave velocity was elevated in both S‐RhoBTB1 and non‐transgenic mice receiving Ang II infusion, indicating a persistence of arterial stiffness. Unlike Ang II infusion, restoration of RhoBTB1 was sufficient to reverse hypertension, vascular dysfunction and arterial stiffness in S‐P467L mice. In S‐P467L mice aorta, the activity of phosphodiesterase 5 (PDE5), an enzyme that degrades vasodilator cGMP, was elevated in S‐P467L and normalized upon RhoBTB1 restoration. We transfected HEK293 cells with RhoBTB1 and PDE5 and found, using co‐immunoprecipitation, that PDE5 physically interacts with RhoBTB1. Moreover, RhoBTB1 increased PDE5 ubiquitination in a Cullin3‐dependent manner. Hence, a potential molecular mechanism underlying RhoBTB1's cardiovascular protective role is that RhoBTB1 acts as a substrate adaptor for Cullin3‐RING dependent ubiquitin ligase. In conclusion, RhoBTB1 might be a novel hypertension therapeutic target, which requires further characterization.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Stabilizing Ryanodine Receptor with Chronic Dantrolene Treatment Does not Affect Hypertension, but Attenuates Atrial Fibrillation Inducibility under Sympathetic Stimulation in Spontaneously Hypertensive Rats
Authors: Lee Jae S , Li Ying , Gerdes A. Martin , Zhang Youhua
Published: June 2021

Introduction

Ryanodine receptor (RyR) dysfunction in skeletal muscle (RyR1) is linked to malignant hyperthermia, and in cardiac muscle (RyR2) is associated with cardiac arrhythmias and heart failure. We hypothesized that RyR dysfunction in vascular smooth muscle (RyR 1,2 and 3) could increase vascular resistance and blood pressure by increasing intracellular calcium level. RyR dysfunction may also contribute to increased atrial fibrillation (AF) in hypertension. Thus, stabilizing RyR function with chronic dantrolene treatment may attenuate hypertension development and AF inducibility in spontaneously hypertensive rats (SHR).

Methods

Male SHR (16 week‐old) were randomized into vehicle‐ (n=10) and dantrolene‐treated (10mg/kg/d, n=10) groups for 4‐weeks. Male Wistar Kyoto (WKY, n=10) rats served as controls. Tail‐cuff blood pressures were recorded before treatment, and at 1‐week, 3‐week during the treatment period. At the end of the 4‐week treatment period, direct blood pressure, echocardiography and hemodynamics were recorded. Atrial fibrillation inducibility tests were performed at baseline and under sympathetic stimulation (SS) with isoproterenol infusion.

Results

Compared with WKY rats, SHR rats had significantly higher blood pressure throughout the experimental period and at the end of 4‐week treatment the systolic blood pressure (SBP) was 212±9mmHg in SHR versus 122±15mmHg in WKY (P<0.001). Dantrolene treatment in SHR had no effect on blood pressure level (208±16 mmHg in dantrolene versus 212±9mmHg in vehicle, P>0.05). AF inducibility was not significantly different between WKY and SHR rats at baseline. However, under SS AF inducibility was significantly increased in SHR compared with WKY rats (58±28% in SHR versus 20±23% in WKY, P<0.01) and dantrolene treatment attenuated AF inducibility under SS in SHR (58±28% in SHR‐vehicle versus 27±21% in SHR‐dantrolene group, P<0.05). Dantrolene treatment also reduced AF duration (0.8±1.4s in dantrolene group versus 10.0±15.0s in vehicle group, P<0.05).

Conclusions

: Stabilizing RyR with dantrolene treatment did not affect hypertension development in SHR rats, indicating RyR dysfunction does not play an important role in mediating hypertension development in this animal model. SHR rats did not show increased AF inducibility compared with WKY rats at baseline; however, under SS, SHR rats had increased vulnerability to AF induction which was attenuated with dantrolene treatment, indicating that enhanced SS‐induced RyR dysfunction in SHR may be responsible for enhanced AF inducibility in hypertension.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Major discoveries on Spinal Cord Injury‐induced immune response
Authors: Jin Yining , Turley Alexandra E. , Kennedy Rebekah C. , Boss Allison P. , Liu Sheng , Lujan Heidi L. , Kumar Ramya K. , Watts Stephanie W. , Fink Greg D. , DiCarlo Stephen E. , Rockwell Cheryl E
Published: June 2021

Cardiovascular disease (CVD) is a leading cause of death and morbidity for individuals with spinal cord injury (SCI). The risk for significant cardiovascular dysfunction is mediated, in part, by systemic low‐grade inflammation as well as abnormal and unstable autonomic control. Specifically, evidence documents a state of chronic inflammation in individuals with SCI. Understanding the mechanisms responsible for the inflammatory and immune responses to SCI has the potential to reduce the risk for CVD and positively impact the lives of millions of individuals and families living with SCI. To address this goal, we studied both paraplegic and tetraplegic rats to determine the effect of SCI on immune function. Splenic immune cells were collected from male Sprague Dawley paraplegic, thoracic2–3 (T2–3) and tetraplegic, cervical6–7 (C6–7) rats (16 weeks post‐transection). We found that SCI impacted both the adaptive and innate arms of the immune system. Evidence of adaptive immune impairment was shown through increased production of IgM and IgG antibodies by unstimulated B cells following spinal cord injury, most notably in the paraplegic group. We also observed a robust increase in IFNg production by activated T cells from tetraplegic and paraplegic animals. The increased production of IFNg (a Th1 cytokine) correlated with an increase in two other Th1 cytokines, TNFa and GM‐CSF. Although there was a modest increase in IL‐4 production by activated T cells from SCI rats, this did not correlate with other Th2 cytokines, such as IL‐5 and IL‐13. Overall, splenic T cells from SCI rats appear to be predisposed to a Th1‐like response. The innate immune system was shown to be modulated after SCI through an effect on NKT‐like cells. There was an increase in the percentage of NKT‐like cells (CD3+CD161+) in the SCI rats that was most prominent in the paraplegic group. Taken together, these data suggest that SCI results in alteration of innate and adaptive immune cell percentages and function, potentially impacting the immune and inflammatory responses following the injury to the spinal cord.

Support or Funding Information

NHLBI HL070687 NIEHS ES024966 NHLBI HL122223

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Phasic, Rapidly‐Propagating Calcium Transients Occur in a Non‐Muscle Cell Network within the Mouse Urinary Bladder Wall
Authors: Tykocki Nathan R. , Hennig Grant W. , Koide Masayo , Wellman George C , Nelson Mark T.
Published: June 2021

Multiple species, including humans, exhibit “non‐voiding” or “transient” contractions of the bladder wall during filling that are accompanied by large bursts of activity from bladder sensory nerves. This suggests that transient contractions play an important role as sensors of bladder fullness, but how transient contractions are generated remains unclear. Using genetically‐encoded Ca2+ indicator mice and novel macroscopic imaging techniques, we sought to determine what Ca2+ signals drive TC generation and coordination across the bladder wall. We utilized mice that constitutively express the Ca2+ indicators GCaMP5 or GCaMP6f as an expression‐dependent fate map of smooth muscle cells (Acta2 promoter) or non‐muscle cells (Trpv1 promoter) within the urinary bladder wall. We discovered that transient pressure events (TPEs) are actually the integration of numerous micro‐contractions of the bladder wall. These micromotions vary in position, frequency and duration, but result in regular, phasic increases in intravesical pressure. Ca2+ events in urinary bladder smooth muscle (UBSM) were restricted to small patches muscle cells and seemed to occur stochastically. Interestingly, we discovered a network of cells within the bladder wall of Trpv1‐GCaMP6f mice that were neither smooth muscle cells nor nerve fibers. This network exhibited extremely rapid and phasic Ca2+ transients that propagated quickly across the entire bladder wall, suggesting that the cells were electrically coupled. The slower waxing and waning of the high‐frequency Ca2+ transient intensity closely aligned with the frequency of TPEs. Surprisingly, this network of cells was unresponsive to the TRPV1 agonist capsaicin, suggesting that TRPV1 channels were no longer functional in these cells. These data suggest that the bladder wall micro‐motions underlying TPEs may be driven by phasic Ca2+ transients that occur in a non‐muscle cell network within the bladder wall.

Support or Funding Information

Supported by NIH K01DK103840 (NRT) and R37DK053832 (MTN).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effects of heart rate variability biofeedback training on psychological state and cardiac autonomic regulation in stressed people
Authors: Arsac Véronique , Blons Estelle , Spiluttini Beatrice , Arsac Laurent M
Published: June 2021

Introduction

Psychological stress is common in our fast‐paced society and strongly influences mental and physical well‐being. Specific training methods have been recently proposed to deal with the negative effects of stress. heart rate variability biofeedback training, a method whereby the subject controls an unusually breathing rate to reach cardiac coherence, has been shown to reduce anxiety and improve cardiac autonomic dynamics in diseased people as well as in young competitors. The present study was designed to examine the effects of short sessions of biofeedback (BFB) training in subjects classified as being severely stressed.

Methods

Twenty‐four participants characterized by a high level of state anxiety, were randomly assigned into a BFB group (n=12) or a control Group (n=12). In the BFB group, cardiac coherence training using a biofeedback device (URGOfeel®, URGOTECH) was conducted during 5 weeks, 5‐min twice a day.

Subjects completed two sessions of tests (before and after 5‐weeks BFB training). Each session consisted in 4 conditions, a baseline “quiet” condition, a condition of cognitive tasks (to assess different domains of executive functioning), and two conditions of cognitive tasks associated to two levels of environmental‐induced stress. To create gradual level of environmental stress, the experimental context was modified by generating visual and sound interferences with negative feedback and time pressure. Heartbeat intervals were recorded (Polar Belt) for 10‐min both at baseline and after 5‐weeks BFB training and was assessed in temporal domain (RMSSD) and from non‐linear analyses (entropy index calculated from MultiScale Entropy, MSE). Participants filled out a series of questionnaires on‐line, notably the Spielberger state anxiety questionnaire (STAI) and the NASA‐TLX to measure the impact of stress on anxiety and workload, before and after each session and conditions.

Results

Before BFB training the induced stress, was associated with a high level of anxiety and a low entropy when compared to baseline and cognitive tasks conditions. After BFB training, both psychological state and entropy in cardiac dynamics were improved in every condition.

Conclusion

the present study confirms the blunting of physiological complexity in heart rate dynamics in stressed subjects especially under acute stress. The phenomenon is generally associated with an altered heart‐brain interconnectivity and a lesser adaptive capacity to everchanging environments. The main outcome here was the efficiency of (very) short BFB training sessions to restore an improved autonomic control in stressed subjects whatever their environment.

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 the Menstrual Cycle on Hemoglobin Mass
Authors: Keller Melissa Faith , Lalande Sophie
Published: June 2021

The impact of the menstrual cycle on oxygen‐carrying capacity remains equivocal. Previous studies reported either reductions or no significant changes in hemoglobin concentration during the follicular phase when compared to the luteal phase of the menstrual cycle. Changes in plasma volume associated with fluctuating estrogen and progesterone levels likely contribute to the variations in hemoglobin concentration observed throughout the menstrual cycle. Thus, measures of hemoglobin concentration do not accurately represent the oxygen‐carrying capacity of the blood. Hemoglobin mass represents a more direct measure of oxygen‐carrying capacity. However, the impact of menstrual blood loss on hemoglobin mass remains unknown. Therefore, the purpose of this study was to determine the effect of the menstrual cycle on hemoglobin mass in pre‐menopausal women. Twenty women (age: 23 ± 6 years, height: 167 ± 7 cm, weight: 66 ± 13 kg) with a regular menstrual cycle using (n = 9) and not using hormonal contraceptives participated in the study. Hemoglobin mass was assessed using the carbon monoxide rebreathing technique on three separate visits. Visits for women using hormonal contraceptives were scheduled in the early follicular phase (3–5 days post‐onset of menses), late follicular phase (14 days post‐onset of menses), and late luteal phase (10 days after the late follicular visit). Visits for women not using hormonal contraceptives were scheduled in the early follicular phase (3–5 days post‐onset of menses), late follicular phase (1–2 days post‐surge of luteinizing hormone in urine), and late luteal phase (10 days after the late follicular visit). While hemoglobin concentration was nearly significantly different across phases of the menstrual cycle (early follicular: 13.1 ± 1.2 g/dL, late follicular: 12.7 ± 0.8 g/dL, late luteal: 12.8 ± 0.9 g/dL, p = 0.08), hemoglobin mass did not significantly differ between menstrual cycle phases (early follicular: 615 ± 62 g, late follicular: 609 ± 66 g, late luteal: 606 ± 69 g, p = 0.90). Thus, menstrual blood loss has no significant impact on hemoglobin mass or oxygen‐carrying capacity in women with a regular menstrual cycle.

Support or Funding Information

Small Research Grant of the College of Education of the University of Texas at Austin.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Albuterol Improves Lung‐Emptying Dynamics in Patients with Cystic Fibrosis
Authors: Guo Winston , Baker Sarah E , Wiggins Chad C , Joyner Michael J , Dominelli Paolo B
Published: June 2021

Objective

The slope ratio (SR) is a metric that uses maximal expiratory flow‐volume (MEFV) curves to quantify lung‐emptying dynamics. SR values between 0.5–2.5 indicate homogeneous lung‐emptying, while values >2.5 are suggestive of heterogeneous lung‐emptying. Albuterol and exercise are commonly used to improve airflow in patients with cystic fibrosis (CF); however, the effects of these treatments on lung‐emptying dynamics are unknown. We hypothesized that SR values would decrease following albuterol and/or exercise, and that these decreases would be more pronounced following albuterol‐with‐exercise.

Methods

Nine patients (25±2 yrs, n=4 male, 5 female) diagnosed (genotype or sweat chloride) with CF underwent three interventions: i) albuterol (2.5 mg in 3 mL saline), ii) 30 mins of exercise (50% peak wattage), and iii) albuterol and exercise together. MEFV curves (spirometry) were obtained at 10 time points: immediately before (Pre) and 15 minutes after (T15) interventions. Forced expiratory volume in 1 second (FEV1) and forced expiratory flow for 25–75% (FEF25–75) of the forced vital capacity (FVC) were calculated for each curve. SR was calculated along the MEFV curve as the ratio between the tangent and chord slopes at serial volumes (200 mL increments), and SR values from 80%‐20% FVC were averaged to produce a single SR for each MEFV curve.

Results

Compared to exercise, albuterol and albuterol‐with‐exercise elicited greater increases in FEV1 (Pre: 3.00±0.26 vs 2.99±0.25 vs 3.06±0.23 L, p>0.05; T15: 3.00±0.27 vs 3.27±0.30 vs 3.34±0.28 L, p=0.03; exercise vs albuterol vs exercise‐with‐albuterol, for each comparison respectively), FEF25–75 (Pre: 2.52±0.40 vs 2.53±0.40 vs 2.57±0.36 L/s, p>0.05; T15: 2.48±0.39 vs 3.04±0.54 vs 3.10±0.43 L/s, p=0.04), and FVC (Pre: 4.19±0.38 vs 4.17±0.38 vs 4.22±0.37 L, p>0.05; T15: 4.16±0.39 vs 4.35±0.38 vs 4.40±0.41 L, p=0.02), as well as greater decreases in SR (Pre: 1.51±0.15 vs 1.56±0.12 vs 1.58±0.12, p>0.05; T15: 1.54±0.15 vs 1.46±0.17 vs 1.43±0.17, p=0.02). Changes in FEV1, FEF25–75, FVC, and SR were not different between albuterol and albuterol‐with‐exercise conditions (p>0.05). Reductions in SR were related to increases in FEV1 following interventions (r=−0.55, p<0.01).

Conclusions

In contrast to exercise, albuterol caused CF patients to exhibit greater increases in FEV1, FEF25–75, and FVC, along with greater decreases in SR. There was no additive effect of exercise on albuterol. Changes in FEV1 and SR were inversely correlated. These data suggest that albuterol promotes bronchodilation and homogeneous lung‐emptying in CF patients, and that the SR metric is effective for assessing patterns of bronchodilation following administration of different bronchodilators.

Support or Funding Information

Supported by HL131151 (SEB) and Mayo Clinic Internal Funding

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Quantifying Maximal Oxygen Uptake using Lean Body Mass in Children with Obesity
Authors: Bhammar Dharini M , Marines‐Price Rubria , Wilhite Daniel P , Bernhardt Vipa , Adams‐Huet Beverley , Gupta Olga , Martinez‐Fernandez Tanya , Babb Tony G
Published: June 2021

Introduction

The purpose of this study was to examine whether maximal oxygen uptake (V̇O2max) prediction equations based on lean body mass can overcome the confounding effect of fat mass on quantification of cardiorespiratory fitness in children with obesity.

Methods

Forty‐nine children (23 with obesity; BMI ≥ 95th percentile) completed a dual‐energy x‐ray absorptiometry scan for estimating body composition and incremental maximal and verification exercise tests till volitional exhaustion for estimating V̇O2max. Prediction equations based on lean body mass (LBM) and body mass from Cooper D.M. et al 2016 were used to predict V̇O2max [Boys: (0.059 × LBM) − 0.103; (0.052 × body mass) − 0.266. Girls: (0.055 × LBM)–0.187; (0.037 × body mass) + 0.022].

Results

In children without obesity, predicted V̇O2max based on body mass was 100 ± 10mL/min higher than predicted V̇O2max based on LBM (P < 0.001). In children with obesity, predicted V̇O2max based on body mass was 906 ± 33mL/min higher than predicted V̇O2max based on LBM (P < 0.001). Predicted V̇O2max based on body mass was more strongly associated with fat mass (r = 0.81) compared with predicted V̇O2max based on LBM (r = 0.51); P<0.001. The V̇O2max vs. LBM slope was similar for children with (0.040 L·min−1·kg−1) and without obesity (0.043 L·min−1·kg−1). Percent predicted V̇O2max based on LBM was 13% lower in children with obesity compared with children without obesity (P < 0.001). Percent predicted V̇O2max based on body mass was 37% lower in children with obesity compared with children without obesity (P < 0.001).

Conclusions

Referencing V̇O2max to body mass substantially underestimates cardiorespiratory fitness in children with obesity due to the confounding effect of metabolically inactive fat mass. It would be prudent to measure LBM and reference V̇O2max to LBM for a less biased estimation of cardiorespiratory fitness in children with obesity.

Support or Funding Information

This research was supported by NIH R01 HL136643, Texas Health Presbyterian Hospital Dallas, King Charitable Foundation Trust, and unrestricted funds from Dr. Pepper Snapple.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Monitoring Brown Adipose Tissue in Alaskan Sled Dogs: A Pilot Study
Authors: Kromrey Laura , Duffy Lawrence , Reynolds Arleigh , Dunlap Kriya
Published: June 2021

Brown adipose tissue (BAT) has the unique function of burning energy to create heat through the process of non‐shivering thermogenesis. Activation of BAT in humans as a possible means of combating obesity is an active area of research, yet reliable methods for recognizing and monitoring BAT activation still need to be developed and validated. The purpose of this study was to assess the feasibility of thermal imaging for monitoring BAT activation in an in vivo animal model, specifically Alaskan sled dogs, which have been used extensively as models in cold‐weather metabolism and nutrition research. In this pilot study, BAT activation was monitored monthly over 4 months in a cohort of five sled dog puppies. Thermal images of the chest region and blood samples were collected before and after a cold exposure treatment. The thermal images were used to compare the temperature of the chest region pre‐ and post‐cold exposure, reasoning that a change in temperature would occur with BAT activation. Concentrations of two plasma biomarkers associated with non‐shivering thermogenesis, irisin and fibroblast growth factor 21 (FGF21), were measured in each blood sample. Although this pilot study did not have significant findings, it has produced a base of knowledge and methodology that is being used in current studies. Given the potential benefits of BAT activation for human health, the validation of thermal imaging as a non‐invasive monitoring technique and the use of an animal model could better inform the treatment of metabolic diseases.

Support or Funding Information

Funding was provided by Nestlé Purina and the UAF BLaST Program. Research reported in this publication was supported by the National Institute Of General Medical Sciences of the National Institutes of Health under Award Numbers UL1GM118991, TL4GM118992, or RL5GM118990. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes 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.
Role of K+ channels and NOS on human eccrine sweat gland function
Authors: Mack Gary W , Smith Ben , Rowland Ben
Published: June 2021

The non‐selective NOS inhibitor L‐NAME has been shown to reduce cholinergic‐mediated sweating in humans. We tested the hypothesis that the effect of NOS inhibition on sweat gland out is mediated through the ability of NO to activate KCa1.1 channels. We generated stimulus response curves using: lactated‐Ringers, 50 mM TEA, 20 mM L‐NAME and a cocktail of 50 mM TEA plus 20 mM L‐NAME (n=10). Local sweat rate (SR) was measured by passing dry gas through a small sweat capsule mounted on the skin. The skin was stimulated at a constant current intensity of 2.5 mA for 30 s at frequencies of 0.2, 1, 2, 4, 6, 8, 12, 16, 32, and 64 Hz using two small stainless‐steel stimulating electrodes. We plotted the area under the SR‐time curve versus stimulus frequency. All data were expressed as the area under the local SR‐time curve (AUC) and normalize to the peak AUC response during Saline control trials (% AUC peak). During Ringers perfusion, peak local sweat output averaged 99.6 ± 5.7 AUC % peak which was significantly (p<0.0001) reduced by application of 50 mM TEA to 61.7 ± 22.7 AUC %peak. Addition of 20 mM L‐NAME to the 50 mM TEA solution produced an additional 20% reduction in peak SR to 42.5 ± 21.1 %AUC peak (p <0.05). These data support the hypothesis that sudomotor control of sweat gland activity is modulated by the presence of TEA sensitive K+ channels and the activity of an intrinsic NOS enzyme in the epithelial cells of the human sweat glands. Further, the ability of L‐NAME to produce an additional reduction in peak SR following 50 mM TEA indicates that the influence of NOS on local SR is not likely mediated via a modulation of TEA sensitive K+ channels.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Heat Acclimation Program for Firefighters Reduced Heat Stress and Improved Thermal Sensation and Thermal Comfort during Exercise Wearing a Firefighting Suit
Authors: Takeda Ryosuke , Imai Daiki , Kawai Eriko , Ota Akemi , Saho Kosuke , Morita Emiko , Suzuki Yuta , Yokoyama Hisayo , Takahashi Hideya , Hayashi Hideshi , Kimura Tasuku , Okazaki Kazunobu
Published: June 2021

Introduction

Firefighters are exposed to an excessive heat stress and at the risk of heat‐related disorders and heat stroke during firefighting because they are wearing a firefighting suit with high insulation. Heat acclimation for firefighters would reduce the heat stress and the risk of heat‐related disorders during firefighting. Typical programs of heat acclimation require a few hours per day for 5 to 10 consecutive days and an artificial hot environment, those are unrealistic and impossible for them during their daily duty. In this study, we tested whether a heat acclimation program for firefighters performed in fire stations during daily duty with a simple exercise protocol wearing thermal insulation clothes would reduce heat stress and improve thermal sensation (TS) and thermal comfort (TC) during exercise wearing with a firefighting suit.

Methods

Twenty male active firefighters (age; 20–50 years old) underwent a ~1‐month heat acclimation program (interval stair stepping exercise for 32 min, 4 sets of 5 min at high‐intensity – 3 min at low‐intensity, ~9 times/month) wearing a rain coat (9 subjects, RC group) or a firefighting suit (11 subjects, FS group) in addition to their regular training at their fire stations. Before and after intervention, they underwent a graded walking test (1.5, 3.0, 4.5, and 6.0 km/hour for 9 min each with 5% grade) wearing a firefighting suit in a climate chamber (25°C ambient temperature, 40% relative humidity). Heart rate (HR), esophageal (Tes) and mean skin temperatures (Tsk), skin blood flow (SkBF) and sweat rate (SR) at chest were continuously monitored and TS and TC were determined every minute. When Tes reached 38.5 °C, test was terminated before the end.

Results

After intervention, at rest, Tes and Tsk decreased and TS improved only in FS group, while TC improved in both groups (all, p < 0.05). In addition, Tes, Tsk, and also HR decreased and TS and TC improved during exercise in both groups (all, p < 0.05), though the reduction after intervention in these variables were prominent in FS group compared with RC group. SkBF and SR at chest in response to increased Tes were enhanced more in FS group than RC group.

Conclusions

The heat acclimation program performed in fire stations during daily duty in firefighters wearing thermal insulation clothes reduced heat stress with enhanced thermoregulatory responses and improve thermal sensation and comfort during exercise wearing a firefighting suit. Clothes that have higher thermal insulation (firefighting suit) would be more effective for the heat acclimation program.

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