bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chronic effects of angiotensin II on NHE3 promoter involve several intracellular signaling pathways and Sp1/Egr‐1 binding site
Authors: Queiroz‐Leite Gabriella Duarte , Rebouças Nancy Amaral 
Published: June 2021

Previous studies have shown that 24h exposure to 10−11 M angiotensin II (AII) stimulated NHE3 activity and increased NHE3 protein content and mRNA levels in OKP cells. The purpose of this study was to verify the effects of AII on the NHE3 gene promoter activity and its regulatory mechanisms. OKP cells were used in transient transfection assays. Four fragments of NHE3 promoter cloned into a vector containing the reporter gene Firefly luciferase were studied (−2095/+55, −152/+55, −85/+31 and −65/+31). The promoter activity of the fragment −65/+31 was significantly increased after 24h‐treatment with 10−11M AII. This increase was abolished by pretreatment with losartan (AT1R inhibitor). Two mutations were performed in this fragment. The mutation at the Sp1/Egr‐1 binding site completely abolishes the AII stimulatory effect, whereas the mutation at the AP2 binding site partially revert this effect. In order to verify the mechanisms involved in this stimulatory response, we used intracellular signaling pathways inhibitors. Our results showed that cytochrome P450, PI3K, PKA and MAPK pathways are involved in this process, while PLC and JAK/STAT pathways do not participate. These data reveal that AII chronic stimulatory effects on NHE3 proximal promoter occur through AT1R and are dependent on the Sp1/Egr‐1 binding site integrity. This response involves activation of different intracellular signaling pathways.Financial Support: FAPESP and CNPq
The effect of hyperglycemia on Achilles tendon structural properties in the rat
Authors: Moore M Scott , Gump Brian , Tedeschi Jamie , Peterson Amity , Kim Paul J , Broderick Thomas , Carroll Chad C 
Published: June 2021

Diabetes is often associated with chronic foot ulcers leading to limb amputations. Ulcerations appear to develop, in part, because of increased pressures on the plantar aspect of the foot due to an equinus deformity (limitation of ankle joint dorsiflexion). Equinus deformity may be due to changes in the elastic properties of the Achilles tendon. Elevated blood glucose levels result in glycation induced collagen cross‐linking and studies of rat tail tendon suggest that hyperglycemia alters the content of tendon collagen and normal cross‐links. To our knowledge collagen content has not been assessed in the Achilles tendon of diabetic rats. Twenty male Sprague‐Dawley rats (8 weeks) were randomly assigned to control (n=7) or streptozotocin‐induced diabetic (n=11, 55 mg•kg body weight) groups. After 10 weeks tendons were evaluated for collagen content via HPLC. Weight gained was higher in the control rats (control: 162.7±14.9 g, diabetic: 62.3±10.1 g). Hyperglycemia did not alter the content of collagen in the Achilles tendon (control: 305.3±14.9, diabetic: 301.4±18.9 μg collagen/mg wet weight and control: 682.3±31.7 and 692.2±58.0 μg collagen/mg dry weight). It does not appear that changes in total collagen can explain the functional changes noted in the Achilles tendon of diabetics. Although total collagen was unaffected additional studies of cross‐link content and collagen I to III ratios are warranted.Funding: Midwestern University
Measuring drug effects on exercise endurance under extreme environmental conditions in rats using motorized wheels
Authors: Radiloff Daniel R. , Wu Chan , Zhao Yulin , Hanna Gabi , Irwin David , Hamilton Karyn , Schroeder Thies 
Published: June 2021

ObjectivesExercise capacity in laboratory animals is typically measured using treadmills which require large spatial allocation and have poor habituation efficacy, making it unsuitable for high throughput application. We present a novel rat exercise system involving motorized rodent wheels that has high habituation efficiency, and due to small spatial allocation allows for high throughput experimentation.MethodsFemale Sprague Dawley rats were habituated to maintain position in motorized wheels at low speed for 10 min daily. Wheel speed was increased incrementally over 10 days. On testing days, animals received i.p. injections of nifedipine (40 mpk), or iron sucrose (5 x 1 mpk daily) or vehicle. Animals were then exposed to escalating exercise burden under hypoxia. Exhaust signs included sliding, hanging, tail position, and time until self motivated movement after removal from wheel.Results>90% of rats ran proficiently within 10 days of habituation. Nifedipine significantly decreased time run to exhaust. Iron sucrose on the other hand significantly enhanced exercise performance under hypoxia vs. control.ConclusionWe established a novel, ergonomic, and efficient system to measure exercise capacity in rats under hypoxia for high throughput experimentation. This system has application in various disciplines, including exercise physiology, environmental medicine, and drug development.
Inflammation and muscle damage markers of football athletes during heavy physical training with DHA supplementation
Authors: Dobson Justin P , Oliver Jonathan M , Riechman Steven E , Crouse Stephen F 
Published: June 2021

Docosahexaenoic acid (DHA) is a C22:6 omega‐3 fatty acid that has been shown to reduce inflammation. Our study examined serum inflammatory (GM‐CSF, IL‐6, IL‐8, TNF‐α, interferon‐γ, CRP) and muscle damage (creatine kinase, LDH, ALT, AST, alkaline phosphatase) markers following 2 g/d of supplemented, purified algal DHA (E;n=24) or placebo (P;n=28) in American collegiate football athletes during preseason training. Fasted blood was drawn three different times: 1) Summer (S) before starting supplements (T1); 2) August, pre‐camp (PRE) after 35 d supplementation (T2); and 3) August, post‐camp (POST) after 52 d supplementation (T3). A 2x3 ANCOVA with repeated measures (covaried for race; CRP for weight change). A significant group x time interaction was observed in IL‐8 (p<0.05). Other markers of inflammation showed no differences between groups (p>0.05). POST CRP was significantly higher than PRE (p<0.001). POST levels of creatine kinase, LDH, ALT, AST, alkaline phosphatase were significantly (p<0.001) increased compared to S and PRE in both groups. Preseason training can elevate muscle damage markers. DHA supplementation did affect IL‐8 levels during preseason training of collegiate football athletes.Funding provided by Martek Biosciences Corp., Columbia, MD and The Sydney & J.L. Huffines Institute for Sports Medicine & Human Performance
Effect of exercise training on vascular reactivity in inbred strains of mice
Authors: Kim Seung Kyum , Avila Joshua , Massett Michael Peter 
Published: June 2021

The aim of this study was to characterize the strain‐dependent differences in vascular reactivity in aorta from sedentary and exercise‐trained mice. Male mice (n ≈ 8/strain) from 5 inbred strains (129S1, 129X1, C57BL/6J, FVB, PWD) were assigned to either sedentary or exercise training (EX) groups. EX mice completed a 4‐wk treadmill running protocol (5 days/wk, 60 min/day, 60% of max speed). After training, aortic rings were suspended for isometric tension recording. Exercise training had no effect on vascular reactivity in any strain. Significant strain effects were found for maximal responses to phenylephrine (PE) and potassium chloride (KCl). For each agent, aorta from PWD had the lowest (PE = 5.4 ± 2.0 mN, KCl = 12.0 ± 2.6 mN) and aortas from 129‐substrains had the highest (PE = 16.4 ± 3.5 mN, KCl = 17.9 ± 3.3 mN) responses. Relaxation responses to acetylcholine were also different across strains, with aortas from the 129‐substrains having the lowest (73.0 ± 16.8%) and aorta from the FVB having the highest (90.6 ± 12.6%) responses. Relaxation responses to sodium nitroprusside were not different across strains. Strain‐dependent differences in sensitivity were observed for all agents tested. The large difference in maximal responses and sensitivity to vascular agents across mouse strains suggests that genetic background significantly affects vascular responsiveness.Supported by NIH grant HL085918 to MPM
The mechanism of L‐Glutamine‐mediated protection requires the activation of cell surface receptors
Authors: Niederlechner Stefanie , Baird Christine , Wischmeyer Paul 
Published: June 2021

IntroductionL‐Glutamine (GLN), integrin/Src and epidermal growth factor receptor (EGFR) pathway can induce cellular protection.HypothesisGLN activates the O‐glycosylation pathway, HSF‐1 and HSP expression via cell swelling by the activation of integrin/Src and EGFR signaling to prevent apoptosis.MethodsIEC‐6 cells treated with GLN (up to 20 mM), with or without the integrin inhibitor GRGDSP (50 μM), inactive control peptide GRGESP (50 μM), Src‐kinase inhibitor PP‐2 (75 μM), or EGFR inhibitor AG1478 (10 μM). Cell survival via MTS assay 24h post‐HS (44ºCx50min). O‐glycosylated proteins, HSF‐1, HSPs, Bax, cleaved caspase‐3 and PARP levels determined via Western blot, cell area size via fluorescence microscopy after non‐lethal HS (43ºCx45min).ResultsGRGDSP significantly attenuated GLN‐mediated increases in cell area size, HSF‐1 and O‐GlcNAc levels after HS (p< 0.05; n>3). GLN‐mediated increases in HSPs were decreased by GRGDSP and PP2 by 70%–100% after HS (p< 0.05; n=4). GRGDSP, PP2, and AG1478 attenuated GLN's protection by 70%–100% (p< 0.05; n=4). GRGDSP increased GLN‐mediated decreases in cleaved caspase‐3, cleaved PARP and Bax levels after HS, indicating that GLN lost its protection (p<0.05; n=3). GRGESP control peptide had no effect on GLN‐mediated protection pathways.ConclusionIntegrin/Src and EGFR signaling seem to be vital components of GLN's protective mechanism. R01 GM078312
Functional analysis of novel CLCNKB mutations in patients with Bartter syndrome
Authors: Keck Mathilde , L'Hoste Sébastien , Genete Mathieu , Grand Teddy , Vargas‐Poussou Rosa , Blanchard Anne , Lourdel Stéphane , Teulon Jacques 
Published: June 2021

Bartter's syndrome is a hereditary renal tubulopathy characterized by salt‐wasting and hypokalaemic metabolic alkalosis, which can be due to loss‐of‐function mutations in genes encoding ClC‐Kb / Barttin chloride channel. Here, we investigated 7 novel CLCNKB mutations (L81P, V170M, G246R, R351P, G424R, R438H and L439P) and the A204T mutation (Waldegger et al. J. Biol. Chem., 2000, 275: 24527–33).We studied WT and ClC‐Kb mutants in Xenopus laevis oocytes using two‐electrode voltage‐clamp for measuring ClC‐Kb currents and chemiluminescence for evaluating surface expression. Cellular expression was investigated in HEK cells using western‐blots. For the two latter purposes, we designed a ClC‐Kb construct carrying an extracellular FLAG epitope that does not alter ClC‐Kb currents.No significant current was recorded with G246R, G424R, R438H and L439P mutants. L81P, V170M, A204T and R351P mutants produced 35–70% lower currents as compared to wild‐type. Accordingly, chemiluminescence showed that G246R, G424R, R438H and L439P were not addressed to the plasma membrane while surface expression of L81P, V170M, A204T and R351P was decreased by 30–85%. These results were confirmed by western‐blot on HEK cells, which indicated a defect in membrane targeting for all mutants.We conclude that all these CLCNKB mutations are pathogenic and considerably alter membrane targeting of the channel.
Mitochondrial gene variant contributing to coronary artery disease
Authors: Almontashiri Naif A. , Teng Allen C.T. , Chen Hsiao‐Huei , Cheng Brian L.M. , Alam Mohammad A. , Ta Matthew , Roberts Robert , Langer Thomas , McBride Heidi M. , Stewart Alexandre F.R. 
Published: June 2021

Genome‐wide association studies (GWAS) have identified genetic variants that are associated with the risk for coronary artery disease (CAD), but the functional significance of these loci has remained obscure. We identified a genetic variant associated with CAD risk that changes the sequence of a mitochondrial protease called paraplegin (SPG7) and confirmed this association by meta‐analysis of 14 GWAS including 22,000 CAD cases and 60,000 controls. The variant changes an arginine residue at position 688 to a glutamine residue in the protease domain of SPG7. Most mutations in SPG7 cause a loss of protease function leading to spastic paraplegia. Although the Gln688 variant was considered benign in terms of spastic paraplegia, we have evidence that it is in fact a protease gain‐of‐function variant. We observed a strong correlation between the presence of the variant allele and the level of mature active SPG7 in peripheral lymphocytes, as well in primary cultures of human aortic smooth muscles. Consistent with increased SPG7 protease activity, increased production of cytochrome c oxidase subunits, ATP synthesis, cell proliferation and ROS production were seen in cells stably expressing this variant. Our data suggest that this gain of function may also be detrimental to mitochondrial function with aging. Our study is the first to link a mitochondrial matrix AAA protease variant to the risk of CAD.(Supported by CIHR)
Effect of protein blend vs whey protein ingestion on muscle protein synthesis following resistance exercise
Authors: Reidy Paul , Walker Dillon K , Dickinson Jared M , Gundermann David M , Drummond Micah J , Timmerman Kyle L , Fry Chris S , Cope Mark , Mukherkea Ratna , Volpi Elena , Rasmussen Blake B 
Published: June 2021

Resistance exercise followed by the ingestion of amino acids or protein causes an additive stimulation of muscle protein synthesis (MPS). Proteins such as whey are digested at a fast rate whereas soy and casein are digested at an intermediate and slow rate, respectively. To determine if ingestion of a protein blend (soy and dairy protein) extends the post‐exercise MPS response compared to whey protein we conducted a double‐blind, randomized clinical trial in 20 young adults before and after ingestion of ~20g of the protein blend or whey (N=10 per group) given 1h after a bout of high‐intensity leg resistance exercise. We utilized stable isotopic methods to measure the mixed muscle protein fractional synthetic rate (FSR) and western blotting to examine mTORC1 signaling. Muscle biopsies (vastus lateralis) were collected at baseline and at two time points during post‐exercise (Early: 1–3h & Late: 3–5h post‐ex). We report differences between the two beverages as Protein A and B (data will be unblinded at the EB meeting). FSR increased by ~40–70% in both groups during Early and remained elevated into Late. Protein A and B also activated mTORC1 signaling to a similar extent following exercise, yet Protein B tended to be greater. We conclude, from these preliminary data that following resistance exercise, the ingestion of a protein blend enhances mTORC1 signaling and MPS similarly to that of whey protein.Grant Funding Source : Solae LLC
Dietary spray‐dried plasma attenuates inflammation caused by transport stress and increases pregnancy rate of mated female mice
Authors: Song Minho , Liu Yanhong , Lee Jeonjae , Che Tung M. , Soares-Almeida Juliana A. , Campbell Joy M. , Polo Javier , Crenshaw Joe D. , Chun Ju Lan , Seo Seongwon , Pettigrew James E. 
Published: June 2021

Previous studies indicated that prolonged transport stress immediately after mating resulted in a low pregnancy rate (10%). Dietary inclusion of 8% spray‐dried plasma (SDP) consistently and markedly increased the pregnancy rate to 49%, and 1% SDP increased it to 35%. We hypothesized that SDP increases pregnancy rate of mated female mice by attenuating inflammation caused by transport stress. Mice (C57BL/6 strain) were shipped from Bar Harbor, ME to Urbana, IL on the day the vaginal plug was found [gestation day (GD) 1], arriving at the laboratory in IL on GD 3. Mice were randomly assigned to diets [0 (CON), 1, or 8% SDP]. Randomly selected mice were euthanized each day from GD 3 to 7 to collect blood and uterus to measure cytokines, Creactive protein (CRP), and cortisol by ELISA and to check pregnancy by inspection. Indicators of inflammation and stress were greatest soon after arrival on GD 3 or 4 (time, P < 0.05). SDP decreased (P < 0.05) uterine TNF‐α (45–49%) and IFN‐γ (18‐ 20%), and serum TNF‐α (27–41%), CRP (17–19%), and cortisol (8‐ 12%), compared with CON, but increased (P < 0.05) uterine TGF‐ β1 (15–16%). SDP markedly increased (P < 0.05) pregnancy rate (176–190%) compared with CON. No difference was found between 1% and 8% SDP. These data support the hypothesis that SDP increases pregnancy rate of mated female mice under these conditions by attenuating inflammation.Grant Funding Source: APC, Inc., Ankeny, IA
A global partnership to improve nutrition medicine in Vietnam
Authors: Lenders Carine M , Henry Elizabeth ,   AFINS group
Published: June 2021

BackgroundAlthough the nutrition status in Vietnam has improved dramatically this past decade, malnutrition is still prevalent and studies in the hospital setting are lacking. The Vietnamese government recently urged hospitals to start addressing nutrition.ObjectiveTo create a partnership between Boston University (BU), Bach Mai Hospital (BMH), the National Institute of Nutrition (NIN), and the Hanoi Medical University (HMU) to improve patient outcomes and health services in Vietnam.InterventionAfter an in‐depth assessment, the AFINS partners have developed a hospital‐centered integrative model of nutrition medicine.ResultsWe found that the rate of acute undernutrition in a general hospital ranges between 30–45% based on age while overnutrition is rare. With support from AFINS partners, the academic and hospital leadership is creating new training opportunities and systems applicable to the Vietnamese context.ConclusionsUsing government guidelines and feedback, AFINS partners plan to develop strategies to further evaluate, sustain, and disseminate this model. Support from the Abbott Fund.
Pharmacological Actions of L‐cysteine on Isolated Bovine Irides
Authors: Stroud Destinee Denea , Kulkarni Madhura , Njie-Mbye Ya Fatou , Opere Catherine A. , Ohia Sunny E. 
Published: June 2021

PurposeTo investigate the pharmacological actions of L‐cysteine, a substrate for hydrogen sulfide (H2S) production on isolated bovine irides.MethodsIsolated bovine iris muscle strips were set up in organ baths containing oxygenated Krebs buffer (pH 7.4) at 37□ C. Changes in isometric tension were recorded via grass FT03 Force‐displacement transducers and analyzed using PolyView software. The relaxant action of L‐cysteine on basal and carbachol‐induced tone was studied in the presence or absence of enzyme inhibitors of the biosynthetic pathways for H2S and prostanoids.ResultsL‐cysteine (0.1 nM –100 μM) elicited a concentration‐dependent relaxation of basal and carbachol‐induced tone in bovine irides. In contrast, L‐cysteine had no relaxant effect on basal tone in porcine irides. Inhibition of cyclooxygenase with flurbiprofen (3 μM) had no significant effect on relaxation induced by L‐cysteine. The inhibitor of cystathionine β‐synthase, aminooxyacetic acid (30 μM) significantly (p<0.02) reduced the relaxation induced by L‐cysteine.ConclusionL‐cysteine can relax isolated bovine irides, an effect that is dependent on intramural biosynthesis of H2S. Prostanoids are not involved on this relaxant effect. Bovine irides appear to be more sensitive to the inhibitory action of L‐cysteine than its porcine counterpart, indicating that species differences exist in the response to this substrate.
Antioxidant, anti‐glycation and ROS scavenging activities of Plantago asiatica
Authors: Nam Mi-Hyun , Hong Chung-Oui , Son Da-Hee , Oh Jun-Gu , Lee Kwang-Won 
Published: June 2021

Plantago asiatica (PA) is widely distributed in Korea, China and Japan. It has traditionally been used as a folk remedy for various health benefits such as cough treatment and liver protection. The objective of this study was to demonstrate the reduction of excessive intracellular reactive oxygen species (ROS) through antioxidants and the anti‐glycation activity of PA. Dried roots of PA were boiled in ethanol for three hours, evaporated and lyophilized with a freeze‐dryer. The freeze‐dried powder of PAE was dissolved in distilled water and the solution was loaded onto a column packed with Diaion HP‐20 resin, which had been equilibrated with distilled water. The column was eluted with 2 L of 25% ethanol. Twenty‐five percent ethanol‐containing fraction (PAE‐D) was collected, and then concentrated using rotary vacuum evaporator. The concentrate was freeze‐dried. The total polyphenol content, flavonoid content, FRAP value, and DPPH‐ SC50 of PAED were 231.7 μg gallic acid equivalents/mg dry matter (DM), 211.7 μg quercetin equivalents/mg DM, 3.23 mmol FeSO4/mg DM and 282.0 μg DM/mL, respectively. The effects of the PAE‐D on AGE fluorescence were dose‐dependent, reaching 71% inhibition at 1 mg/mL of extract. In addition ROS scavenging assay were performed to investigate the possibility of PAE‐D in improving endothelial dysfunction‐induced diabetic complications. Treatment of PAE‐D significantly lowered the fluorescent formation due to advanced glycation reaction.Grant Funding Source : iPET, Korea
Novel stretchable electronics platform for simultaneous high‐density electrical and optical recordings from ex vivo hearts
Authors: Gutbrod Sarah R , Laughner Jacob I , Sulkin Matt S , Xu Lihzi , Bonifas Andrew P , Ying Ming , Yu Alice , Rogers John A , Efimov Igor R 
Published: June 2021

Although there are protocols for studying high‐resolution cardiac propagation on the bench top, there is a great need to develop a comparable monitoring strategy on intact hearts in vivo. Novel, stretchable electrodes offer the ability to measure electrical data from the dynamic beating heart without interrupting mechanical contractions. We developed a mechanically compliant, transparent sock electrode for measuring surface electrograms from a beating Langendorff perfused rabbit heart. Using a matrix of nanomembrane transistors, submillimeter and submillisecond resolution can be obtained. The purpose of this study was to correlate simultaneous high‐density surface electrograms with optical mapping recordings in explanted heart preparations. Perfusion was maintained at a constant pressure of 60 mmHg and electrical recordings were collected prior to and after mechanical uncoupling with Blebbistatin in sinus rhythm, epicardially paced through an external stimulator and through the electrode array, and during pinacidil induced ventricular arrhythmias. Optical mapping was performed only after mechanical uncoupling. Preliminary results show that the propagation maps created from the array of electrodes contains adequate activation, repolarization and conduction velocity information of normal and aberrant rhythms, verified by the optical recordings.supported by NIH Grant RO1 HL067322