bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Skeletal Muscle Carnosine Content on Apoptotic Signaling
Authors: Church David D , Hoffman Jay R , Townsend Jeremy R , Jajtner Adam R , Beyer Kyle S , Oliveira Leonardo , Fukuda David H , Stout Jeffrey R
Published: June 2021

Carnosine (Carn) has a pluripotent role in skeletal muscle (SkM) physiology, enhancing intracellular buffering, acting as an antioxidant, antiglycating and ion‐chelating agent, and also acts as a diffusible Ca2+/H+ exchanger. Carn role as an antioxidant may reduce apoptosis, but has not been fully investigated in human SkM. Therefore, the purpose of this study was to investigate if SkM Carn influences apoptotic signaling in response resistance exercise. Fourteen recreational active men completed a lower‐body resistance exercise protocol consisting of the squat, leg press, and leg extension exercises. Blood samples were obtained before (PRE), immediately‐(IP), one‐(1H), five‐(5H), 24‐(24H) & 48‐(48H) hours post‐resistance exercise. SkM biopsies were obtained from the vastus lateralis at BL, 1H, 5H, & 48H post‐resistance exercise. SkM carnosine content was assessed via HPLC. Participants were placed into either a high Carn (HI: n = 7; Carn = 12.25 ± 2.40 mmol·kg−1WW) or a low Carn (LO: n =7; Carn = 5.60 ± 1.27 mmol·kg−1WW) group for analysis. Multiplex signaling assay kits were used to quantify phosphorylation status of apoptotic markers (JNK, FADD, p53, BAD, Bcl‐2). Circulating measures of muscle damage [myoglobin (Mb)] and oxidative stress [8‐hydroxy‐2′ – deoxyguanosine (8OHdG)] were assessed via ELISA. To control for BL differences a repeated measures analysis of covariance was used to analyze SkM data. Area under the curve (AUC) analysis was determined by the trapezoidal method. Although no significant interactions between the groups were observed for FADD, BAD, p53, Mb, or 8‐OHdG (p > 0.05)in response to resistance exercise, significant interactions were observed for JNK (p = 0.019) and Bcl‐2 (p = 0.032). Post‐hoc analysis indicated a significantly greater response at 1H for HI compared to LO in JNK (p = 0.035), while a trend towards an increase (p = 0.065) was observed for Bcl‐2. In addition, changes in Bcl‐2 and JNK following exercise were only significant in HI (p = 0.009 and p = 0.007, respectively), but not LO (p = 0.370 and p = 0.369, respectively). AUC analysis for 8OHdG indicated that circulating concentrations for HI (6,107.5 ± 2,144.6 ng·mL−1·min−1) was significantly (p = 0.037, D = 1.25) less than LO (8,838.7 ± 2,222.3 ng·mL−1·min−1). In conclusion, our results indicated that participants with higher Carn have a reduction in pro‐apoptotic proteins, with an attenuated circulating oxidative stress response to exercise.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Expression of endothelin type B receptors (EDNRB) on smooth muscle cells is controlled by ternary complex factors and the actin cytoskeleton
Authors: Krawczyk Katarzyna Karina , Skovsted Gry Freja , Perisic Ljubica , Rippe Catarina , Dreier Rasmus , Berg Jais Oliver , Lykkesfeldt Jens , Hedin Ulf , Swärd Karl
Published: June 2021

Endothelin signaling plays an important role in physiology and disease and one of the endothelin receptors, the type B receptor (ETB or EDNRB), is known to be highly plastic, being upregulated in smooth muscle cells by arterial injury and following organ culture in vitro. Herein, we hypothesized that this transcriptional plasticity may arise in part because EDNRB is controlled by ternary complex factors and by the myocardin family coactivator MKL2. In line with this hypothesis we found significant correlations between the ternary complex factors ELK3, FLI1 and EDNRB, and between MKL2 and EDNRB at the mRNA level in human arteries. Overexpression of MKL2 in human coronary artery smooth muscle cells (HCASMC) led to a 30‐ fold induction of EDNRB, and this effect was antagonized by myocardin (MYOCD) which also correlated negatively with EDNRB at the tissue level. Overexpression of ELK3 and FLI1 induced expression of EDNRB, whereas the expression of classical smooth muscle markers was reduced. Depolymerization of actin using latrunculin B (LatB) increased EDNRB on both mRNA and protein levels, and increased calcium responses on stimulation with the ETB‐selective agonist sarafotoxin 6c (S6c) and endothelin 1 (ET‐1). Pretreatment with LatB in organ culture increased S6c and ET‐1‐induced contraction. We also found that ROCK inhibition using Y27632 induced EDNRB expression, and that the effect of LatB is antagonized by MAP‐kinase inhibition. Transcript‐specific primers and promoter reporter assays showed that the EDNRB_2 isoform is regulated by LatB in HCASMC. We finally demonstrate that the mRNA level of EDNRB is increased in rat carotid lesions and human carotid plaques, and that ELK3/FLI1 induction closely parallels EDNRB induction. In all, these studies uncover transcriptional control mechanisms for the endothelin type B receptor (EDNRB) that may explain its plasticity and could be targeted for therapy.

Support or Funding Information

This study was supported by grants from the Medical Faculty and The Royal Physiographic Society. KKK was supported by Marie Curie ITN Small Artery Remodelling of European Union.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Magnesium Deficiency Attenuates Vascular Smooth Muscle Contraction in Rat Aorta
Authors: IESAKI Takafumi , KAKIGI Ryo , WATANABE Makino
Published: June 2021

Magnesium (Mg) deficiency has been reported to be associated with the development of various cardiovascular diseases including hypertension, however, vascular responses in Mg deficient state have not been fully elucidated. We have reported that Mg deficiency attenuates both voltage‐gated and receptor‐operated vascular smooth muscle (VSM) contraction without affecting maximal force development of contractile apparatus. The purpose of the present study is to further examine the mechanism(s) involved. Male Sprague‐Dawley rats were fed an Mg‐deficient diet (Mg content; 4.5 mg/100 g diet) and deionized water for eight weeks, and then the thoracic aorta were excised to measure isometric tension in organ chambers. CaCl2‐induced contraction in the presence of calcium (Ca2+) ionophore ionomycin under Ca2+‐free condition was significantly reduced in Mg deficient group (Mg‐Def). Prostagrandin H2 analogue U46619‐ induced contraction under Ca2+‐free condition was also greatly decreased in Mg‐Def, whereas direct protein kinase C activator phorbol 12,13‐dibutyrate‐induced contraction was not attenuated. These results suggest that Mg deficiency might impair, at least in part, the pathways which increase Ca2+ sensitivity of VSM.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Endothelial dysfunction can be reversed in obese humans and mice by overexpression of endothelial Kir2.1 channels
Authors: Fancher Ibra S. , Adamos Crystal S. , Ahn Sang Joon , Phillips Shane A. , Levitan Irena
Published: June 2021

The vascular endothelium is an important regulator of vascular tone. Acute changes in mechanical stressors, such as blood flow (fluid shear) and pressure, are converted into chemical signals by the endothelium to control vasomotor function. We recently showed that endothelial Kir2.1 channels are critical to the vasodilatory response to increases in blood flow through eNOS and NO production. It is well established that obesity causes endothelial dysfunction likely through impairment of nitric oxide signaling/bioavailability. Furthermore, obesity impairs the vasculature of visceral adipose depots while arteries in the subcutaneous adipose appear unaffected. Therefore, we tested the role of endothelial Kir2.1 in obesity‐induced endothelial dysfunction in vascular beds of spatially distinct adipose depots in obese humans and in a diet‐induced obese mouse model. Mice were fed a high fat, high cholesterol diet for 4 or 8 weeks prior to analysis of vascular function via response to flow in an ex vivo arterial preparation. Endothelial function of arteries from both subcutaneous and visceral adipose depots were tested. After 4 weeks of high fat feeding, no differences were observed in vascular function between arteries from either adipose depot nor when compared to control mice fed a normal chow diet. However, after 8 weeks visceral arteries from high fat fed mice had a significantly blunted response to flow, while subcutaneous arteries retained a full dilatory response. Overexpressing endothelial Kir2.1 using adenoviral transduction with expression driven by the VE‐Cadherin promoter in visceral arteries of diet‐induced obese mice rescued the response to flow suggesting that Kir2.1 channel function or expression may be impaired exclusively in arteries of visceral adipose of obese mice. Importantly, we observed similar findings in obese human arteries from visceral and subcutaneous adipose biopsies collected during bariatric surgery.

Support or Funding Information

NIH R01 HL073965 (IL)American Heart Association 16POST27000011 (ISF)NIH 5T32HL007829‐24 (ISF)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Pulmonary Vasoconstriction and Vascular Remodeling Play Role in Reactive Pulmonary Hypertension in Rats
Authors: Odintsov Igor , Chovanec Milan , Banasova Alena , Hampl Vaclav , Herget Jan
Published: June 2021

Introduction

The majority of clinical cases of pulmonary hypertension (PH) are caused by left heart failure. Some patients with venous PH induced by left heart pressure overload develop increase in resistance in the arterial part of the pulmonary circulation (reactive PH). We developed a new animal model of reactive PH caused by left heart pressure overload. We tested hypothesis that pulmonary arterial vasoconstriction and/or pulmonary vascular remodeling play role in our rodent model of reactive PH.

Methods

Left heart pressure overload was induced in adult male Wistar rats by partial intravascular obstruction of the ascending aorta. Three weeks later the experimental rats (group E, n=6) were compared to controls (group C, n=7). In isolated lungs perfused with salt solution with albumin we studied hemodynamic changes in pulmonary circulation by analysis of perfusion pressure increments induced by increasing perfusion flow (P/Q relationship). The P/Q relationship measurement was repeated after adding sodium nitroprusside into perfusate to reveal presence of pulmonary arterial vasoconstriction. In lung histology we counted remodeled peripheral pulmonary vessels in the group E compared to controls.

Results

The slope of the P/Q relationship was significantly increased in the group E compared to controls (0.112±0.003 mmHg.mL−1.min−1 vs. 0.0046±0.002 mmHg.mL−1.min−1; p<0.0001). Sodium nitroprusside did not alter the slope in controls (0.043±0.002 mmHg.mL−1.min−1). In the group E, sodium nitroprusside reduced the slope to a value not different from that in controls (0.044±0.001 mmHg.mL−1.min−1). In lung histology, 74 % of the small pulmonary vessels had muscularized media in the group E, compared to only 24 % in controls (p<0.01).

Conclusion

Pulmonary vasoconstriction and pulmonary vascular remodeling are involved in the new model of reactive pulmonary hypertension in rats.

Support or Funding Information

Grants: GAUK 210216 and GACR 17‐11223S

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
On the Mechanism of Flow Sensing by Guinea Pig Carotid Endothelial Cells
Authors: Espinosa‐Tanguma Ricardo , Hernández‐Méndez Aurelio
Published: June 2021

It is known that luminal facing endothelial G‐protein coupled receptors (GPCRs) are affected by flow. In human blood vessels bradykinin produces a relaxing effect whereas in guinea pig its effect is vasoconstrictive and affected by flow.

Objetive

to study the mechanism by which flow is sensed by endothelial cells.

Methods

we have used guinea pig carotid arteries to evaluate the effect of flow on the contractile response to bradykinin and cultured carotid endothelial cells to know the expression pattern of p‐SRC and p‐ERK in response to flow.

Results

We have found that in guinea pig carotid artery the flow‐dependent vasoconstrictive effect of bradykinin is augmented by 5 min luminal exposure to heparinase or alfa‐chymotrypsin enzymes suggesting that the flow sensor of the bradykinin receptor (BR) is associated to a carbohydrate residue and/or a protein segment of the receptor present in the extracellular face of the plasma membrane. By looking at the available molecular structure of the BR we have identified a segment of the N‐terminus that could be acting as the flow sensor by a very simple physical mechanism. On the other hand, by using carotid cultured endothelial cells we have found that flow decreases the expression of p‐SRC protein and does not change the p‐ERK expression.

Conclusions

the mechanism by which flow is sensed by endothelial cells is still on debate. However, one mechanism for sensing the flow could be located at the extracellular segment of the protein receptor. The N‐terminus segment of the BR could move depending on the flow velocity and, as a consequence, increasing or decreasing the availability of the BR to its ligand.

Support or Funding Information

Supported by Conacyt 223350 to RET.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Endothelium‐dependent vasorelaxation and blood pressure are preserved in mice with chronic hyperendothelinemia
Authors: Grunewald Zachary Ian , Jurrissen Thomas , Ball James R. , Woodford Makenzie , Walsh Lauren , Ramirez Francisco , Brown Scott , Aroor Annayya , Paradis Pierre , Schiffrin Ernesto , Bender Shawn , Martinez‐Lemus Luis , Padilla Jaume
Published: June 2021

Endothelin‐1 (ET‐1) is a potent vasoactive peptide implicated in the development of glucose intolerance, endothelial dysfunction, and hypertension. However, whether the detrimental metabolic and vascular effects caused by chronically elevated circulating ET‐1 (i.e., hyperendothelinemia) are exacerbated by obesity remains unknown. Accordingly, six‐week‐old female transgenic mice overexpressing human preproET‐1 selectively in the endothelium (eET‐ 1) and non‐transgenic (i.e., wild‐type) littermates were fed either chow or a Western diet (46% Kcal fat, 36% Kcal carbohydrate) to induce obesity for 21 weeks, creating four distinct groups (n=9–11/group): wild‐type chow‐fed, eET‐1 chow‐fed, wild‐type Western diet‐fed, eET‐1 Western diet‐fed. eET‐1 mice exhibited a 27‐fold (chow) and 18‐fold (Western diet) elevation in plasma ET‐1 concentration relative to wild‐type mice. Notably, despite such marked elevations in plasma ET‐1, blood pressure (systolic and diastolic) and aortic stiffness, assessed by pulse wave velocity, were unaltered in eET‐1 mice relative to wild‐type counterparts, regardless of diet. Similarly, independent of diet, ex vivo endothelium‐dependent relaxation (i.e., vasomotor responses to acetylcholine and insulin) in femoral and coronary arteries were not different between eET‐1 and wild‐type mice, and modestly enhanced in the aorta of eET‐1 mice. eET‐1 mice also exhibited suppressed phenylephrine‐induced aortic vasoconstriction relative to wild‐type mice, an effect that was amplified by Western diet‐feeding. Chow‐fed eET‐1 mice exhibited mild glucose intolerance and this genotype effect was not aggravated by diet‐induced obesity. Collectively, contrary to our hypothesis, we find that endothelial overexpression of ET‐1 does not lead to impaired endothelial function in lean or obese mice. The retention of a functional endothelial phenotype and suppression of alpha‐adrenergic vasoconstriction in this model of chronic hyperendothelinemia may contribute to the preservation of normal blood pressure. Follow‐up experiments are ongoing to delineate potential homeostatic compensatory adaptations that underlie this largely conserved cardiometabolic phenotype in the presence of chronic hyperendothelinemia.

Support or Funding Information

NIH, SCAN

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
All‐Extremity High‐Intensity Interval Training and Moderate‐Intensity Continuous Training Improve Aerobic Fitness and Cardiac Function in Type 2 Diabetes
Authors: Christou Demetra D. , Hwang Chueh‐Lung , Lim Jisok , Yoo Jeung‐Ki , Kim Han‐Kyul , Hwang Moon‐Hyon , Handberg Eileen M. , Petersen John W. , Holmer Brady J. , Lapierre Stephanie S. , Sakarya Yasemin
Published: June 2021

High‐intensity interval training (HIIT) on the treadmill has been reported to be more effective in improving aerobic fitness and cardiac function compared with moderate‐intensity continuous training (MICT) in adults with cardiometabolic disorders. However, middle‐aged and older adults with type 2 diabetes (T2D) are often unable to tolerate weight‐bearing exercise which may hinder HIIT and MICT on the treadmill. Therefore, the purpose of this randomized clinical trial was twofold: 1) to test if non‐weight bearing all‐extremity HIIT and MICT are feasible in adults with T2D aged 50 to 79 yrs; and 2) to test whether HIIT is more effective in improving aerobic fitness and cardiac function than MICT. Fifty‐three sedentary adults with T2D (age: 63±1 yrs), free of cardiovascular disease, were randomized to HIIT (n=21), MICT (n=18) or non‐exercise control (CONT; n=14). HIIT (4×4‐min intervals at 90% of peak heart rate; HRpeak) and isocaloric MICT (70% of HRpeak) were performed on an all‐extremity ergometer, 4 times/week for 8 weeks under supervision. Aerobic fitness was assessed by oxygen consumption during an incremental maximal exercise test. Left ventricular (LV) function was assessed during rest by two‐dimensional echocardiography including conventional and tissue Doppler. All measures were obtained at pre‐ and post‐intervention. Approximately 80% of participants randomized to all‐extremity HIIT and MICT completed the exercise intervention. Aerobic fitness improved by 11% in HIIT (22.4±1.2 vs. 24.9±1.4 ml/kg/min, pre‐ vs. post‐intervention; P<0.0001) and 7% in MICT (21.4±1.3 vs. 23.0±1.3 ml/kg/min; P=0.004 and P=0.4 for HIIT vs. MICT), whereas it did not change in CONT (21.4±1.5 vs. 21.3±1.2 ml/kg/min; P=0.9). Ejection fraction, a measure of LV systolic function, increased in both HIIT and MICT by ~2% (HIIT: 54.7±0.7 vs. 56.6±0.9%; P=0.007 and MICT: 54.6±1.4 vs. 56.4±1.2%; P=0.04), whereas it remained unchanged in CONT (56.0±1.2 vs. 54.9±1.1%; P=0.2). Diastolic function was not significantly affected by the intervention (P≥0.06). In conclusion, all‐extremity HIIT and MICT are feasible in middle‐aged and older adults with T2D and are equally effective in improving aerobic fitness and LV systolic function.

Support or Funding Information

This work was supported by the National Institutes of Health (NIA AG 050203).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Augmented myogenic constriction in the SHR pre‐glomerular renal arteries protects the kidneys from elevated blood pressure
Authors: Nademi Samera , Lu Chao , Carlisle Rachel E. , Dickhout Jeffrey G.
Published: June 2021

Background

Spontaneously Hypertensive Rats (SHR) have chronically elevated blood pressures (BPs) at 30 weeks of age (systolic: 191.0 ± 1.0, diastolic: 128.8 ±0.9). However, despite this chronic malignant hypertension, SHR kidneys remain relatively free of pathology and do not display significant proteinuria, due to having an augmented myogenic constriction (MC) in their kidneys [1–2]. In contrast to the SHR, high‐salt fed Dahl Salt Sensitive (DSS) rats have lower BPs (systolic: 163.2 ± 1.4, diastolic: 119.4 ± 1.1), yet show extensive renal pathology, proteinuria, and blunted myogenic response (MR) in the pre‐glomerular vessels. We hypothesize that augmented MC in the SHR pre‐glomerular vessels is due to prostanoid synthesis, providing renal protection.

Methods/Results

To investigate this hypothesis, we used the inhibitor of prostaglandin H2 synthesis, indomethacin, in the SHR and WKY pre‐glomerular arteries. We also utilized N omega‐nitro‐L‐arginine (LNNA) to examine the effect of nitric oxide blockade on MC, and nifedipine to determine the dependence of MR on L‐type calcium channels. Further, we used a second vascular bed, the mesenteric arcades, to assess the effects of these modulators on myogenic tone. The results showed an enhanced MR in the SHR pre‐glomerular vessels compared to the WKY. Indomethacin attenuated MC in both WKY and SHR renal arteries and nifedipine completely blocked this response in both WKY and SHR pre‐glomerular vessels. In mesenteric arteries, indomethacin decreased MR at high intraluminal pressures in the WKY, and lower pressures in the SHR. LNNA did not change MR in either WKY or SHR, while nifedipine inhibited MC in both WKY and SHR vessels.

Conclusions

SHR pre‐glomerular arteries show an augmented MC compared to WKY vessels. Prostaglandin increases MC in both WKY and SHR renal arteries. In mesenteric arteries, prostaglandin increases MC at high intraluminal pressures in WKY, but lower pressures in the SHR. Nitric oxide does not affect MR in mesenteric arteries, but L‐type calcium channels play a key role in this response in both renal and mesenteric vessels.

Support or Funding Information

This work was supported by Canadian Institutes of Health Research grants to Dr. Jeffrey G. Dickhout (PJT148499).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Inhibition of the human colonic thiamine pyrophosphate (TPP) uptake process by the pro‐inflammatory cytokine, TNF‐α and IFN‐γ
Authors: Srinivasan Padmanabhan , Chu Brian D , Geltz Erica T , Thompson Morgan M , Said Hamid M
Published: June 2021

Thiamin in its pyrophosphate form, i. e., thiamin pyrophosphate (TPP), is essential for normal cellular functions due to its involvement in energy metabolism, maintenance of normal cellular redox state, and mitochondrial structure/function. Humans and other mammals obtain thiamin through intestinal absorption, as they lack the ability to synthesize the vitamin de novo. The vitamin is obtained from both dietary and microbiota sources. A considerable amount of the vitamin provided by the later source exists in the form of TPP. We have previously shown the existence of a specific and high‐affinity carrier‐mediated uptake process for TPP in human colonocytes (Am J Physiol Gastrointest Liver Physiol. 2012; 303: G389–95) and determined the molecular identity of the system involved (product of the SLC44A4 gene) (J Biol Chem. 2014; 289: 4405–16). We have also cloned the promoter of the SLC44A4 gene and delineated certain aspects of its transcriptional and post‐transcrptional regulation (Am J Physiol Cell Physiol 308: C750–C757, 2015; Am J Physiol cell Physiol. 2017; ajpcell.00169.2017). Pro‐inflammatory cytokines tumor necrosis factor‐α (TNF‐α) and interferon‐γ (IFN‐ γ) are involved in the pathogenesis of inflammatory bowel diseases and has been shown to affect transport physiology of a variety of substrates. The effect of prolonged‐exposure of colonic epithelial cells to TNF‐α and IFN‐ γ on uptake of TPP has not been examined and was investigated in this study. The results showed that exposing the human‐derived colonic epithelial NCM460 cells to clinically relevant concentration of TNF‐α (20 ng/ml for 48hr) and IFN‐ γ (30 ng/ml for 48 hrs) leads to a significant (p < 0.01) inhibition in carrier‐mediated TPP uptake. This was associated with a significant reduction in the level of the expression of SLC44A4 protein, mRNA and hetronuclear RNA (hnRNA) levels, as well as in a significant inhibition in the activity of the SLC44A4 promoter. We also observed a significant decrease in the expression of the transcription factor ELF3 (which drive the SLC44A4 promoter) following exposure to TNF‐α and IFN‐ γ. Studies are in progress to understand the exact molecular mechanism involved in this process. This study for the first time provide clear evidence that exposure of human‐derived colonic epithelial NCM460 cells to TNF‐ α and IFN‐ γ negatively affect the colonic TPP transport, and that the effect is mediated at the level of transcription of the SLC44A4 gene.

Support or Funding Information

Supported by grants from the DVA and the NIH (DK‐56061, DK58057, and AA 018071)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The effects of starch‐entrapped microsphere supplementation on obesity and insulin resistance in C57BL/6J mice
Authors: McNabney Sean M , Reed Kylee M , Starrs Grace E , Libbey Margaret E , Henagan Tara M
Published: June 2021

Dietary supplementation with the short chain fatty acid butyrate prevents obesity and insulin resistance in mice fed a high fat diet (HFD). Unfortunately, the translational potential of dietary butyrate supplementation is limited due to its teratogenic effects at higher doses. More recently, attention has turned to resistant starches that produce butyrate during their fermentation in the colon as therapeutic agents for attenuating obesity and insulin resistance. These starches represent an effective strategy to enhance endogenous butyrate production. The entrapment of resistant starch in an alginate matrix represents a novel technique to increase fermentable carbohydrate delivery to the colon. The purpose of this study was to assess the effects of starch‐entrapped microsphere (SM) supplementation on body composition, insulin sensitivity and energy expenditure in a murine model of diet‐induced obesity. Male C57BL/6J mice were fed the following diets (N=10/group): 1) low fat diet (LF, 10% kcal fat), 2) HFD (HF, 60% kcal fat), or 3) HFD + 10% wt/wt SM (HF+SM, 60% kcal fat). Body weight and 48 h food consumption were measured weekly. Body composition was assessed weekly using EchoMRI, with scans performed in duplicate. Glucose tolerance tests (N=5/group) were performed after 7 wks of feeding and area under the curve (AUC) was determined. Energy expenditure (N=5/group) was assessed via CLAMS at 9 wks of feeding. All data were analyzed via repeated or one‐way ANOVA and post hoc Tukey tests as appropriate. Body weight, percent fat mass and GTT AUC was significantly greater in HF compared to LF. Energy expenditure and respiratory exchange ratio (RER) were significantly decreased in HF compared to LF; whereas, caloric consumption was increased. Although HF+SM showed significantly increased body weight and percent fat mass relative to LF, both body weight and percent fat mass were significantly decreased compared to HF. There was no significant difference in GTT AUC between LF and HF+SM. HF+SM showed significantly decreased GTT AUC compared to HF. Energy expenditure in HF+SM was not different from LF and was significantly increased compared to HF. RER was significantly decreased in HF+SM compared to LF and not different between HF and HF+SM. Interestingly, food consumption was significantly increased in HF+SM compared to both LF and HF groups. Collectively, our data show that dietary SM supplementation attenuates HFDinduced obesity and insulin resistance through upregulation of whole body energy expenditure, despite increased caloric intake, and may be an effective treatment strategy for obesity and insulin resistance.

Support or Funding Information

This work was supported by a AgSeed grant to TMH.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effect of Aronia melanocarpa Extract on Lifespan and Stress Resistance in C. elegans
Authors: Brown Cyrus , Lopez Virgilio , Lee Elaine C
Published: June 2021

Oxidative stress caused by exposure to reactive oxygen species (ROS) induces widespread damage within the cell. ROS have damaging effects on the structure of DNA, proteins, and lipids, which contributes to the pathology of numerous diseases such as Parkinson's, Alzheimer's, and cancer. Cellular stress response mechanisms serve to mitigate the effects of oxidative stress by using antioxidant compounds to neutralize ROS. Black chokeberry (Aronia melanocarpa) is considered to be an excellent source of antioxidants such as polyphenols, anthocyanins and pro‐anthocyanins. The aim of this study was to investigate whether a crude mixture of Aronia extract would increase lifespan and stress resistance in Caenorhabditis elegans. N2 Bristol strain survival and stress resistance were tested with toxicity (0 mg×mL−1, 0.1 mg×mL−1, 1 mg×mL−1, 5 mg×mL−1, and 10 mg×mL−1, A. melanocarpa) and heat stress assays. Supplementation with 0.1 mg×mL−1 Aronia significantly increased survival as compared to the control condition (p = 0.006). No significant difference in survival was observed with Aronia supplementation during heat stress (p = 0.27). In conclusion, these data suggested Aronia supplementation had a beneficial effect on worm survival. However, more research is necessary to determine its effect on survival and resistance in response to cellular heat stress.

Support or Funding Information

New investigator start‐up, McNair Scholar Program

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
REDD1 Reduces Muscle Metabolism to Foster Adaptation under Fasting
Authors: FAVIER Francois , Britto Florian , Belloum Yassine , Gallot Yann , Cortade Fabienne , Chabi Beatrice , Freyssenet Damien , Carnac Gilles , Rieusset Jennifer , Giorgetti‐Peraldi Sophie , Ollendorff Vincent
Published: June 2021

Aims and background

Regulated in Development and DNA Damage 1 (REDD1) is a stress‐induced protein responsible for the inhibition of the Akt/mTORC1 pathway. This pathway integrates energetic status and oxygen availability to promote protein and glycogen synthesis as well as mitochondrial biogenesis. REDD1 is expressed in response to exercise, hypoxia or fasting and has been observed in the mitochondrial fraction in vitro. Our aim is to characterize the role of REDD1 in skeletal muscle under energetic challenge.

Methods and results

Wild‐type (WT) and REDD1 knockout (KO) mice were deprived of food for 16h and immediately killed before gastrocnemius and tibialis anterior muscles sampling. We observed an overactivation of the metabolic sensor AMPK and a greater glycogen depletion in skeletal muscle of REDD1 KO mice after fasting. In addition, REDD1 deficient mice displayed exacerbation of skeletal muscle atrophy in response to food deprivation compared to WT animals. We then used dexamethasone treatment to induce REDD1 protein expression and showed for the first time that REDD1 is (partly) localized at the mitochondrial‐associated endoplasmic reticulum membranes (MAM) of skeletal muscle fibers, where it is able to inhibit the Akt/mTORC1 pathway. Indeed, REDD1 binds to and reduces the interaction of MAM protein components, resulting in decreased mitochondrial O2 consumption and protein synthesis.

Conclusions

Sustained activity of the Akt/mTORC1 pathway is known to promote anabolic processes and therefore to increase ATP consumption. Our results supports that REDD1 deletion contribute to maintain high fuel demand that in turn leads to skeletal muscle atrophy under fasting. We propose here that a physiological role for REDD1 is to foster skeletal muscle acclimatization during energetic challenges via reduction of O2 and ATP consumption assigned to synthesis processes.

Support or Funding Information

This work was supported by the Agence Française de Lutte contre le Dopage (grant #4299).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Role of COUP‐TFII in Glucose Homeostasis in Dahl Salt Sensitive Rats
Authors: Ashraf Usman Mohammad , Kumarasamy Sivarajan
Published: June 2021

The Interaction between genetic and environmental factors plays an important role in disease progression. One of the major environmental factor includes diets, which governs significant attention based on the broad spectrum of effect in cardiovascular and associated diseases. Consumptions of diets that are rich in calories and salts can significantly increases the risk for developing life threatening cardiovascular events including hypertension and metabolic syndrome. Through GWAS studies, a locus with significant association for hypertension was found in human chromosome 15 containing the gene Chicken Ovalbumin Upstream Promotor Transcription Factor II (COUP‐TFII). To validate this gene, a mutant rat was developed with a 15‐base pair deletion in Dahl Salt Sensitive (SS) rat background. Under high salt diet regimen, the Coup‐TfIImutant rat had an improved cardiac and renal function when compared to SS rats. Being a known transcriptional regulator, Coup‐TfII also plays a role in other physiological events including glucose homeostasis and energy metabolism. In H4IIE rat hepatoma cells, Coup‐TfII expression modulated in response to glucose levels; under high glucose condition Coup‐TfII expression was significantly down‐regulated (p< 0.05); whereas in low glucose condition Coup‐TfII expression was significantly up‐regulated (p< 0.05). In addition, Coup‐TfII protein expression is found to negatively correlate with insulin regardless on the amount of glucose present in H4IIE cells (p< 0.05). Similar to our in‐vitro findings, Coup‐TfII gene expression was significantly up‐regulated in SS rat liver during fasting as compared to re‐fed condition (p< 0.05). Coup‐TfIImutant rat have also showed a significant decrease in fasting blood glucose levels (p< 0.05) compared to SS rat along with a significant decrease in their body weight (p< 0.05). Furthermore, the Coup‐TfIImutant rat demonstrated a superior glucose response and insulin response as measured by glucose tolerance test (GTT) and Insulin tolerance test (ITT) (p< 0.05). Further, under fasting condition the mRNA expression analysis in livers of SS and CoupTfIImutant rats revealed that the key enzymes involved in both beta oxidation and gluconeogenesis was significantly down regulated in Coup‐TfIImutant rats compared to SS rats (p< 0.05). Overall, our preliminary findings suggest that Coup‐TfII is important for glucose homeostasis in SS rats. Further understanding of Coup‐TfII function will help to dissect the relationship between metabolic syndrome and blood pressure regulation in SS rats.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
TFAM Overexpression Prevents Skeletal Muscle Atrophy
Authors: Theilen Nicholas T , Jeremic Nevena , Weber Greg , Tyagi Suresh
Published: June 2021

The current study aims to investigate if the overexpression of the mitochondrial transcription factor A (TFAM) gene in a transgenic mouse model diminishes soleus and gastrocnemius atrophy occurring with hindlimb suspension (HLS). Additionally, we aim to observe if combining concurrent, treadmill exercise training with TFAM transgenic mice prior to HLS has a synergistic effect in preventing skeletal muscle atrophy. Male transgenic mice aged 12–14 weeks old overexpressing the TFAM gene were assigned to a control (T‐Control), 7‐day HLS (T‐HLS), and 14 exercise sessions prior to 7‐day HLS (T‐Ex+HLS) groups and compared to male C57BL/6 (WT) mice (all wild‐type data from prior work currently in submission) aged 12–14 weeks old assigned to Control, 7‐day HLS (HLS), 14 exercise sessions prior to 7‐day HLS (Ex+HLS), and 14 exercise sessions (Ex). Results indicate overexpressing TFAM results in a decrease of 8.3% in soleus weight/bodyweight ratio and 2.6% in gastrocnemius weight/bodyweight ratio after HLS compared to losses in wild‐type mice of 27.1% in soleus weight/bodyweight ratio and 21.5% in gastrocnemius weight/bodyweight ratio after HLS. Our data indicates TFAM may play a critical role in protecting skeletal muscle from disuse atrophy and is correlated with increased expression of antioxidants (SOD‐2) and potential redox balance. Our results also indicate combining exercise with TFAM overexpression had no significant increase compared to wild‐type Ex+HLS. TFAM may be a molecule of interest for future pharmaceutical and therapeutic targeting to treat skeletal muscle atrophy.

Support or Funding Information

The study was supported by NIH Grant HL74185 to SCT.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
PfaR Purification Strategy and Structure Analysis
Authors: Ortiz‐Rosario Melissa Cristina , Rullán‐Lind Carlos , Pérez‐Oquendo Mabel , Morales‐Lozada Yermary , González‐Méndez Ricardo , Baerga‐Ortiz Abel
Published: June 2021

The biosynthesis of polyunstaurated fatty acids (PUFA) in certain bacterial species, is regulated by processes that are not fully understood. One possible factor in the modulation of gene expression in PUFA biosynthesis is pfaR, a putative transcriptional regulator whose gene is encoded directly upstream of pfaA in some bacterial species but entirely absent in others. Here we report the expression of pfaR in Escherichia coli together with its purification by Ni2+ affinity chromatography. Our results show that the majority of pfaR is produced as an insoluble protein that can be reconstituted from inclusion bodies. After inclusion body reconstitution, pfaR remains amenable for affinity purification. Additional bioinformatics analyses indicate the presence of a conserved winged helix‐turn‐helix (wHTH) domain flanked by a number of conserved motifs which include a predicted protein‐protein interaction site. Sequence alignments and motif structure analyses reveal evolutionary divergence in this family of transcriptional regulators, consistent with the likely DNA‐binding function of pfaR. Currently, we are in the process of analyzing pfaR secondary structure using circular dichroism. Future work will include functional analysis using systematic evolution of ligands by exponential enrichment.

Support or Funding Information

This work was supported by the National Institutes of Health [R25 GM061838, R25GM061151‐ 15, 5T34GM007821‐37, T36‐GM‐095335]; and the NationalScience Foundation [CHE0953254].

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Induced pluripotent stem cells derived from different tissue sources and their prospect for osteochondral regeneration
Authors: Danisovic Lubos , Csobonyeiova Maria , Novakova Zuzana Varchulova , Nicodemou Andreas , Varga Ivan
Published: June 2021

A novel approach for stem cell generation is the attempt to induce conversion of the adult somatic cells into pluripotent stem cells so called induced pluripotent stem cells (iPSCs) by introducing specific transcription factors. iPSCs have two essential cell characteristics, they are pluripotent and posses long term cell‐renewal capacity. Additionally, iPSCs can be derived from patient‐specific somatic cells, thus bypassing ethical and immunological issues. The aim of present study was to reprogram human neonatal fibroblasts and adipose stromal cells by episomal reprogramming system. Obtained iPSCs were characterized by methods of molecular biology and microscopy. Distinct colonies of iPSCs started to appear between 14 – 20 days reprogramming and were proved by alkaline phosphatase (AP) live staining. After manual picking the colonies and their subsequent passaging, they did not lose ability to form embryoid bodies, they were positive for AP, Tra‐1‐60, and SSEA‐5. Moreover, obtained iPSCs expressed pluripotency markers Oct4, Sox2 and Nanog, and the expression levels of chondrogenic and osteogenic markers were significantly higher in comparison to control (normal fibroblasts). In summary, we have demonstrated neonatal fibroblasts and adipose tissue stromal cells can be reprogrammed into iPSCs. They shared similar biological and morphological features, and display strong potency of chondrogenic and osteogenic differentiation. Based on obtained results it can emphasized that after further analysis concerns on their biological safety they may be used as patient‐specific cells in regenerative medicine of osteochondral tissues.

Support or Funding Information

Supported by grant APVV under contract No. 14‐0032 and by grant VEGA under contract No. 1/0153/15.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Anti‐inflammatory Peptide Ac‐SDKP is Highly Concentrated in Macrophages of Lymph Nodes
Authors: Romero Cesar Andres , Kumar Nitin , Carretero Oscar Alfredo
Published: June 2021

N‐acetyl‐seryl‐aspartyl‐lysyl‐proline (Ac‐SDKP) is a natural peptide released from its precursor Thymosin β4 (Tβ4) by meprin‐α and the prolyl oligopeptidase enzymes (POP) in secuential step. Ac‐SDKP is hydrolyzed by the angiotensin converting enzyme (ACE). Ac‐SDKP has anti‐inflammatory and anti‐fibrotic effects in heart, aorta and kidney and part of the beneficial effects of ACE inhibitors has been ascribed to the increased levels of Ac‐SDKP. Ac‐SDKP is present in spleen and thymus, however, the presence of Ac‐SDKP in the lymph node has not been studied. We hypothesized that Tβ4, Ac‐SDKP and its releasing enzymes are present in lymph node. Ac‐SDKP concentration was evaluated in Sprague‐Dawley (SD) rat tissues. Tβ4 as well as Meprin‐α and POP enzymes were measured in the lymph node, thymus, spleen and other tissues obtained from SD rats. Ac‐SDKP was measure in several lymph node cell populations obtained by cell sorting. Lymph node showed the highest Ac‐SDKP concentration (181±18.3 ng/mg of protein) followed by the testis, thymus and spleen in SD rats (P<0.001 lymph node vs. testis, thymus and spleen). Meprin‐α and POP activity were present in lymph node, spleen and thymus. Tβ4 and Meprin‐α immunostaining were found to be positive in multinucleated giant cells in the cortical region of lymph node and along the septums; it was also found in the follicular region and germinal center. POP staining was found positive in the cortical region. Co‐localization of POP and the CD68 protein was found in the cortical region but not in the medulla. In the lymph node Ac‐SDKP concentration was higher in Macrophages (CD45+CD68+) in comparison with T lymphocytes (CD45+CD3+) (1.5±1.1*10−3 pmol/cell vs. 0.3±0.1*10−5 pmol/cell, respectively). We conclude that Ac‐SDKP is highly concentrated in lymph node and that all the components of Tβ4/Ac‐SDKP system are present. The releasing enzyme POP is present in Macrophages and these cells have the higher Ac‐SDKP concentration. Our present work provide new information that would be useful in inflammatory regulation in lymph nodes.

Support or Funding Information

National Institutes of Health Grant P01HL028982

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
A Novel, Long‐Lasting μ Opioid Receptor Antagonist Prevents and Reverses the Respiratory‐Depressant Effects of Heroin in Rhesus Monkeys
Authors: Gerak Lisa R , Maguire David R , Woods James H , Husbands Stephen , France Charles P
Published: June 2021

Opioid overdose continues to be a serious public health problem in the US with fatal overdose occurring in at least 115 Americans every day. Naloxone (Narcan®) is increasingly available to reverse respiratory depression, the fatal effect of opioids; however, its relatively short duration of action limits the protection it can provide. SH‐1 is a novel opioid antagonist that has a longer duration of action than other opioid antagonists, including naloxone and naltrexone. The current study examined the ability of SH‐1 to prevent and reverse the respiratory‐depressant effects of heroin using head plethysmography to monitor minute volume (VE) in 4 monkeys breathing air. First, SH‐1 was given before heroin to determine whether it would prevent respiratory depression. The duration of action of SH‐1 was assessed by generating heroin dose‐effect curves at various times (1, 2, 4, and 8 days) after administration of 0.32 mg/kg SH‐1; these effects of SH‐1 were compared to those of naltrexone (0.032 mg/kg). The ability of SH‐1 to reverse the respiratory‐depressant effects of heroin was determined by giving a single injection of heroin to decrease minute volume (VE) followed 30 min later by an injection of either saline or 0.32 mg/kg SH‐1. In the absence of drug (control), average VE (± SEM) was 1531±113 ml/min. Heroin dose dependently decreased VE, and the potency of heroin varied across monkeys with the dose needed to decrease VE to <70% of control ranging from 0.1–1 mg/kg. When given before heroin, SH‐1 and naltrexone prevented the respiratory‐depressant effects of heroin, shifting the heroin dose‐effect curve 6‐fold rightward in each monkey. SH‐1 continued to attenuate the respiratory‐depressant effects of heroin for at least 4 days after administration whereas naltrexone antagonized heroin only on the day it was administered. When heroin decreased VE to <70% of control, subsequent administration of SH‐1 reversed these respiratory‐depressant effects within 30 min. Thus, SH‐1 can both prevent and reverse the respiratory‐depressant effects of heroin and these effects last longer than those of naltrexone. Because of its sustained effects, the novel compound SH‐1 might provide greater protection against the fatal respiratory‐depressant effects of opioids, thereby improving treatment of opioid overdose.

Support or Funding Information

Supported by NIH (R01DA005018) and the Welch Foundation (AQ‐0039).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
BMPR2 and TfR1 Interact to Each Other
Authors: Alanazi Madhawi S. , Mohildien Ashraf M. , Nauli Surya M.
Published: June 2021

BMPR2 (bone morphogenetic protein receptor type‐2) and TfR1 (transferrin receptor protein‐1) play an important role in embryonic development and are involved in cancer formation. Our recent proteomic study indicates that these two proteins are highly expressed in renal epithelial cells, although their functions in the kidney is not well understood. We confirm that both proteins have interaction in our immunoprecipitation study. We also knockdown BMPR2 or TfR1 expression in renal cell epithelia. Compared to scrambled control, knockdown of either BMPR2 or TfR1 results in a cell migration defect. The knockdown cells also show abnormal proliferation and apoptotic indices. In summary, our studies indicate that BMPR2 and TfR1 may share a functional interaction with each other.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.