bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Torso Burn Injury Does Not Exacerbate Thermoregulatory Strain During Exercise‐Heat Stress While Wearing A Military Combat Uniform
Authors: Fischer Mads , Cramer Matthew N. , Huang Mu , Belval Luke N. , Watso Joseph C. , Cimino Frank A. , Secher Niels H. , Crandall Craig G. 
Published: April 2020

The ability to dissipate heat during exercise is impaired in individuals with grafted skin over a large portion of their body. However, it is unknown whether a torso burn injury impairs thermoregulatory function in uniformed military personnel operating in a hot environment.PurposeTo evaluate whether a torso burn injury exacerbates the rise in core temperature during exercise in a hot environment while wearing a military combat uniform.MethodsTen healthy individuals (8 males) performed 60 min of treadmill walking at 5.3 km/h with 3.7 ± 0.9% grade incline (altered to maintain a rate of metabolic heat generation of ~6.0 W • kg‐1) in a 40.0 ± 0.1 °C and 20.0 ± 0.6% relative humidity climate chamber. On separate, randomized occasions, participants wore a standard U.S. Army Combat Uniform and Outer Tactical Vest (Uniform) with or without a simulated burn injury imposed by placing absorbent vapor‐impermeable material across the torso, 20% body surface area (BSA), to hinder evaporative heat dissipation (Uniform + Burn). A third trial was conducted without the uniform or simulated burn with subjects wearing athletic shorts and sports bra for females (Control).Rectal temperature and heart rate were monitored continuously, and metabolic heat production was calculated via indirect calorimetry. The change in outcome measures from baseline to the end of exercise were compared between trials with a two‐way (group × time) repeated‐measures ANOVA.ResultsAt the end of exercise, no differences were revealed (P > 0.05) between the Uniform versus Uniform + Burn trials in all outcome variables: increase in rectal temperature (Uniform: Δ1.16 ± 0.3°C; Uniform + Burn: Δ1.21 ± 0.4°C), thermal sensation (Uniform: 6.0 ± 0.6; Uniform + Burn: 6.2 ± 0.8), rating of perceived exertion (Uniform: 14.2 ± 2.7; Uniform + Burn: 14.1 ± 3.0) and increase in heart rate (Uniform: Δ61 ± 13; Uniform + Burn: Δ56 ± 15 bpm). In contrast, the Control trial showed lower (P < 0.05): increases in rectal temperature (Δ0.93 ± 0.3°C), thermal sensation (4.8 ± 0.7), rating of perceived exertion (11.3 ± 2.2), and increases in heart rate (Δ44 ± 14 bpm) compared to both the Uniform and Uniform + Burn trials.ConclusionA 20% BSA simulated burn on the torso does not exacerbate thermoregulatory strain during exercise in a hot environment while wearing a military combat uniform in healthy young adults. These findings suggest that the risk of heat‐related illness in soldiers with torso burn injuries is no different than non‐injured soldiers when wearing a standard military combat uniform.Support or Funding InformationThis work was supported by awards from the Department of Defense (W81XWH‐15‐1‐0647 to CGC), National Institutes of Health (R01GM068865 to CGC), and a Natural Sciences and Engineering Research Council of Canada Postdoctoral Fellowship (to MNC).
Depletion of HIF‐1α‐mediated Mitochondrial Uncoupling Protein‐4 (UCP4) Expression Sensitizes Temozolomide (TMZ)‐Induced Apoptosis in Glioblastoma
Authors: Chen Jin , Li Zhaozhong , Kolpakova Jenya , Chan Sic L. , Cheng Zixi Jack 
Published: April 2020

IntroductionMitochondrial Uncoupling Protein‐4 (UCP4) UCP4 is exclusively expressed in the brain and has been shown to promote cell proliferation and enhance resistance to mitochondrial toxins by shifting cellular ATP synthesis from oxidative phosphorylation (OxPhos) toward glycolysis. Notably, a recent study demonstrated that the expression of cerebral UCP4 was upregulated when the animals were exposed to acute high‐altitude hypoxia. This upregulation may facilitate the adaptation of malignant glioma cells to their hypoxic microenvironment, and contribute to the subsequent mitochondria remodeling and metabolic reprogramming. UCP4 has become an interesting focus in the regulation of oxidative stress in age‐related neurodegenerative diseases. However, the function and mechanism of UCP4 upregulation under hypoxia remains poorly defined in gliomas.MethodsThe human glioblastoma cell line, U373MG was used for this study. UCP4 expression level under hypoxia was detected using Western Blot. Glioma cell proliferation, anchorage‐independent growth and invasion were evaluated using MTT assay, BrdU incorporation, Soft‐agar colonogenic assay, and Matrigel invasion assay. To silent UCP4, U373MG cells were infected with shRNA against UCP4. LDH release assay was employed to assess whether targeting UCP4 could sensitize the Temozolomine (TMZ) – induced the apoptosis in U373MG cells. The Human UCP4 base promoter region was cloned for Luciferase reporter assays.ResultsHere, we showed that 1) Hypoxia increased UCP4 which promoted tumor progression in gliomas. 2) Knockdown of UCP4 decreased tumor progression and increased the cell sensitivity to TMZ chemotherapy. 3) HIF‐1α regulated UCP4 expression via binding to the UCP4 upstream consensus sequence, and silencing HIF‐1α decreases UCP4 expression.ConclusionsOur data suggested that hypoxia increased UCP4 expression which may contribute to cell adaptation to the hypoxic microenvironment. Targeting UCP4/HIF‐1α, or blocking HIF‐1α binding to UCP4 promoter in glioma cells may offer a new avenue for therapeutic intervention.Support or Funding InformationSupported by the award Florida Center for Brain Tumor Research UF10262 (PI: Zixi Jack Cheng).
Twin enzymes, divergent control: The cholesterogenic enzymes DHCR14 and LBR are differentially regulated transcriptionally and post‐translationally
Authors: Capell-Hattam Isabelle Marie , Sharpe Laura J. , Qian Lydia , Hart-Smith Gene , Prabhu Anika V. , Brown Andrew J. 
Published: April 2020

Cholesterol synthesis is a tightly regulated process, both transcriptionally and post‐translationally. Transcriptional control of cholesterol synthesis is relatively well understood. However, post‐translational regulation has only been examined for a few of the ~20 enzymes in cholesterol biosynthesis. Two of the four sterol reductases, DHCR14 and LBR, share evolutionary ties with a high level of sequence homology, and they uniquely share the same delta‐14 reductase activity in cholesterol biosynthesis. However, the post‐translational regulation of these twin enzymes is poorly understood. Using CHO‐7 cells stably expressing epitope tagged DHCR14 or LBR, we investigated the post‐translational regulation of these enzymes. We found that DHCR14 and LBR undergo differential post translational regulation, with DHCR14 being rapidly turned over, triggered by cholesterol and other sterol intermediates while LBR remained stable. DHCR14 is degraded via the ubiquitin‐proteasome system and via mass‐spectrometry we identified several E3 ligases that modulate basal DHCR14 levels. Significantly, we found that gene expression across an array of human tissues showed an inverse relationship between the C14‐sterol reductases; one enzyme or the other tends to be predominantly expressed in each tissue. Overall, our findings indicate that while LBR tends to be the constitutively active delta‐14 reductase, DHCR14 levels are tuneable, responding to the local cellular demands for cholesterol.Support or Funding InformationThis work was supported by Australian Research Council Grant DP170101178. PhD Candidates were funded by the Research Training Program from the Australian Government Department of Education.
Implementing course‐embedded research projects in a large biochemistry lecture
Authors: Berndsen Christopher 
Published: April 2020

The Biochemistry course at James Madison University is a one‐semester survey course covering everything from atoms to organisms. The students come from a variety of backgrounds and majors, thus it is challenging to make the content accessible to the students and cover the content in adequate depth to prepare students for their careers. I have taken this challenge as an opportunity to develop a series of lecture‐based projects that have students learn biochemistry content through research and experimentation. The large biochemistry lecture section is not an environment where course‐embedded research projects are often found. However, large lecture sections offer the opportunity to expose a large number of students with diverse backgrounds to an open, collaborative research experience. Over the semester long course, students use freely available databases and servers to explore biomolecule structure and function in projects which require students to apply their knowledge of chemistry to biological research questions in an authentic manner. Project topics include spectroscopy, protein purification, drug design, and biomolecule structure prediction and evaluation. In addition to learning the fundamentals of biochemistry, participants develop their skills in experimental design and improve their ability to communicate and disseminate science. To manage the projects on the scale of 50 to 100+ participants at a time, I use the Open Science Framework to store data and report out the findings. From post‐activity assessment, students report increased confidence in their ability to understand fundamental biochemical concepts while also showing increased professional skills. Students also can assemble their projects into portfolios of their work to show to future employers and admissions committees.Support or Funding InformationThomas and Kate F. Jeffress Memorial TrustAccelerating Creative Teaching grant from JMU Libraries
Comparison of Survivor Scores for Differentiation Therapy of Cancer to those for Check Point Inhibition.
Authors: Sell Stewart 
Published: April 2020

Differentiation therapy (DT) is directed to the self‐renewing cancer stem cells, as well as their progeny transit amplifying cells, to force them to mature to terminal differentiation. Differentiation therapy is effective in treatment of neuroblastomas and myeloid leukemias. Check point inhibition (CPI) therapy removes blocks to cancer reactive T‐killer cells and allows them to react to malignant cells and limit growth of cancer. The percent of patients with a given cancer that respond to either therapy is less than hoped for and the duration of response is variable. Multiplying the response rate (% of patients responding to therapy) by the duration of response may be used to derive a survival score for patients treated with DT or CPI. By this criterion DT gives better survival scores than CPI. Yet, CPI is considered a great success, mostly because it may be applied to many different types of cancer and DT is considered relatively ineffective because it is limited to a few specific cancers. On the other hand, the cost of CPI treatment is 10 to 20 times more per patient than DT. Hopefully, future combined treatments and advances in both approaches will increase the effectiveness and decrease the cost of these cancer treatments. For example, resent results with combination therapy of melanoma with two check point inhibitors has substantially increased the survival score.Support or Funding InformationNo support
Activation of Neutral Sphingomyelinase Contributes to Nitric Oxide‐Mediated Flow‐Induced Dilation in the Human Microvasculature
Authors: Schulz Mary K. , Gutterman David K. , Freed Julie K. 
Published: April 2020

Flow induced dilation (FID) is a critical physiological mechanism to maintain tissue perfusion and modulate vascular homeostasis. Recently our laboratory has shown that sphingolipids can influence the endothelial‐derived mediator that is generated in response to flow. Exposure to elevated levels of ceramide, or, inhibition of ceramide metabolism, induces a transition in endothelial‐derived FID mediator from nitric oxide (NO) to hydrogen peroxide (H2O2), the same change in mechanism that occurs with presence of CAD. Interestingly, studies have suggested that endothelial nitric oxide synthase (eNOS) is regulated by ceramide metabolites, such as sphingosine‐1‐phosphate (S1P), suggesting that ceramide is necessary for NO formation due to shear stress. We therefore hypothesized that activation of the shear sensitive, ceramide‐producing enzyme, neutral sphingomyelinase (NSmase) is required for NO‐dependent FID. Resistance arterioles (100–200μm) were dissected from adipose tissue collected from healthy patients and were prepared for videomicroscopy. Following equilibration and preconstriction with endothelin‐1, changes in internal diameter to flow were recorded. L‐NAME (100mM) did not affect FID in healthy arterioles pre‐treated with the NSmase inhibitor, GW4869 (4mM, 16–20hrs), (69.1%±4.9 of maximal dilator capacity, n=4), however dilation was decreased in the presence of PEG‐Catalase (500 Units/ml) (15.2%±9.4, n=3). A similar effect was observed with acute inhibition (30 min) of NSmase. Vasodilation due to increased flow was maintained in the presence of L‐NAME (88.0%±3.5, n=3), however was impaired when exposed to PEG‐Catalase (−5.3%±1.3, n=3). GW4869 alone did not impair the overall magnitude of dilation due to flow (86.1%±3.9, n=2). These findings suggest that while elevated levels of ceramide promote H2O2‐dependent FID, NSmase‐derived products of ceramide are a key component of NO‐mediated signaling in the human microvasculature.Support or Funding InformationK08HL141562
Imoxin Prevents Dexamethasone‐Induced Promotion of Muscle‐Specific E3 Ubiquitin Ligases and Stimulates Anabolic Signaling in C2C12 Myotubes
Authors: Eo Hyeyoon , Valentine Rudy J. 
Published: April 2020

Muscle atrophy is the loss of skeletal muscle mass during several pathological conditions such as long‐term fasting, aging, cancer, diabetes, sepsis and immune disorders. Dexamethasone (DEX), a synthetic glucocorticoid, induces skeletal muscle atrophy by suppression of protein synthesis and promotion of protein degradation. Specifically, DEX increases the levels of muscle specific ubiquitin E3 ligases including MAFbx and MuRF1. The double‐stranded RNA (dsRNA)‐activated protein kinase R (PKR) plays a significant role in mediating inflammation and glucose homeostasis. However, pathological roles of PKR in muscle atrophy are not fully understood. The current study aimed to investigate the effect of imoxin, a PKR inhibitor, on DEX‐induced muscle atrophy in C2C12 myotubes. Myotubes were incubated with imoxin at different concentrations with or without 5 μM DEX for 24 h. Western blotting was performed to measure proteins involved in muscle protein synthesis as well as degradation. DEX significantly augmented the protein levels of MuRF1 and MAFbx (275 ± 5 % and 694 ± 36 %, respectively) compared with serum free control (CON). However, 5 μM imoxin treatment significantly reduced protein levels of MuRF1 by 88 ± 2 % and MAFbx by 99 ± 0 % compared with DEX, respectively. In addition, DEX suppressed FoxO4 phosphorylation (33 ± 9 %) compared to CON, but 5 μM imoxin treatment promoted FoxO4 phosphorylation (735 ± 44 %) compared to DEX. Additionally, DEX stimulated protein ubiquitination compared with control (124 ± 1 %) but 5 μM imoxin treatment reduced protein ubiquitination by 42 ± 4 % compared to DEX. At the same time, 5 μM imoxin treatment stimulated Akt phosphorylation (195 ± 5 %), mTOR phosphorylation (171 ± 21%) and p70S6K1 phosphorylation (314 ± 31 %) under DEX‐treated condition even though DEX treatment did not suppressed Akt/mTOR/p70S6K1 axis. These findings suggest that imoxin protects against DEX‐induced skeletal muscle atrophy by alleviating muscle specific E3 ubiquitin ligases and promoting protein synthesis via Akt/mTOR/S6K1 axis in muscle cells.Support or Funding InformationNone
Neuroinflammation and Age‐Dependent Salt‐Sensitive Hypertension
Authors: Nist Kayla M. , Wainford Richard D. 
Published: April 2020

AimNormal aging and elevated dietary sodium intake have both been identified as contributors to hypertension (HTN). Further, recent data from multiple animal models suggest a role of central inflammation in HTN. Therefore, we speculate that central inflammation plays a role in age‐related salt‐sensitive HTN.MethodsMale Sprague‐Dawley rats aged 3, 8, and 16 months (mo) old were randomly assigned to a normal salt (NS; 0.6% NaCl) or high salt (HS; 4% NaCl) diet for 21 days (n=4–6/group). In a subset of animals (n=6/group) MAP was assessed via femoral artery cannulation. Sympathetic tone was assessed via renal norepinephrine (NE) measured by ELISA on day 21 in a subset of animals (n=6/group). Additional groups of rats were sacrificed via transcardial perfusion using phosphate‐buffered saline and 4% paraformaldehyde (PFA). Brains were extracted and fixed in 4% PFA and 30% sucrose. Immunohistochemistry was performed for markers of microglial (CD11b/c) and astrocyte activation (GFAP) in the paraventricular nucleus (PVN) of the hypothalamus, and assessed using ImageJ software.ResultsWhen fed a NS diet, male rats exhibit age‐dependent HTN (MAP [mmHg] 3 mo 124 ± 2 vs. 8 mo 135 ± 4 vs 16 mo 149 ± 3, p<0.05). When fed a 21‐day HS diet, male rats develop salt‐sensitivite HTN (MAP [mmHg] 3 mo 126 ± 3 vs. 8 mo 143 ± 5 vs. 16 mo 169 ± 1, p<0.5). Aged rats display elevated levels of renal NE, with impaired HS‐evoked suppression of sympathetic tone (renal NE content [pg/mg] 3 mo NS 612 ± 36 vs HS 368 ± 32; 8 mo NS 835 ± 48 vs HS 722 ± 44, p<0.05; 16 mo HS 974 ± 13 vs NS 1019 ± 34, ns). There was no statistical difference between branching complexities on trend lines from Sholl analysis of microglia in all groups. On a NS diet, there is no change in astrocytic density in the PVN with age, (total astrocyte % tissue density: 3 mo 41.58 ± 6.00% vs. 8 mo 43.58 ± 3.65% vs. 16 mo 47.18 ± 3.76%, ns). In 3 mo and 8 mo rats, which do not get salt‐sensitive HTN, there is a significant increase in the activation of astrocytes in the PVN when fed a high salt diet (total astrocyte % tissue density: 3 mo NS 41.58 ± 6.00% vs. 3 mo HS 56.66 ± 4.51%, p<0.05; 8 mo NS 43.58 ± 3.65% vs. 8 mo HS 58.28 ± 2.63%, p<0.05). Sixteen month old rats, which become salt‐sensitive and hypertensive with age, exhibit a failure to increase PVN astrocyte levels on a high salt diet (total astrocyte % tissue density: NS 47.18 ± 3.76% vs. HS 50.66 ± 5.01%).ConclusionsMale Sprague‐Dawley rats become hypertensive and salt‐sensitive with age. On a NS diet, inflammation does not play a role in age‐dependent HTN. However, inflammation plays a role in the salt‐sensitivity of blood pressure mediated by astrocyte reactivity. Our findings propose that with age, PVN astrocytes express a loss of a protective mechanism when challenged with a high salt diet.Support or Funding InformationR01 AG062515, R01 HL139867, R01 HL141406, and R56 AG057687 to RDW
Effect of N‐Terminal Splice Variants and Post‐Translational Modification on Regulation and Activity of Human Cytosolic Malate Dehydrogenase
Authors: Cruz Melanie R. , Balagtas Aaliyah N. , Provost Joseph John 
Published: April 2020

Post‐translational modification via phosphorylation is crucial in regulation of proteins, as well as in interactions between proteins. Human cytosolic malate dehydrogenase (hMDH1) is involved in multiple metabolic pathways including amino acid metabolism and gluconeogenesis, yet information on the impact of phosphorylation is very limited. There is however, growing evidence for regulation of hMDH1 in several disorders. The cytosolic hMDH1 is ubiquitously expressed, however several N‐terminal splice variants have been identified. Like regulation by phosphorylation, no work has been published on the effects of the splice variants on the structure or function of hMDH1. We first determined the impact of N‐terminal deletion for the three most common splice variants on kinetic values. We next analyzed the potential for phosphorylation using three phosphorylation prediction programs and performed meta‐analysis with existing mass spectrometry databases documenting phosphorylation. This bioinformatic analysis identified 24 residues with overlapping phosphorylation predictions between databases. Of these sites, the longest hMDH1 variant (hMDH1v3) has a unique phosphorylation site that is predicted in all databases and has documented phosphorylation in the N‐terminal extension. To examine the potential impact on MDH structure and function phosphomimetic mutations were generated. MDH S5E mutant of hMDH1v3, unique of all splice variants was created while additional mutations of the mid‐length, canonical variant of hMDH1 (hMDH1v1) at residues: S89, S188, S241, and T321 were also generated. These sites were selected for their potential effect on catalysis due to location within the catalytic or binding domain (S188 and S89, respectively), and the overlap of all phosphorylation prediction and mass spectrometry databases (S241 and T321). Our goal in creating phosphomimics is to determine the role of post‐translational modification (phosphorylation) on the regulation of hMDH1 in its stability, kinetic activity, effects on structural changes, and open the potential of phosphorylation of MDH on protein‐protein interactions.Support or Funding InformationNSF EHR‐IUSE Project support NSF‐1726932
Activation of Sirtuin 1 (SIRT1) Signaling by Resveratrol Increases Human Beta‐Defensins‐2 and ‐3 (HBD2, HBD3) Production in Response to Lipopolysaccharide (LPS) in Human Amniotic Epithelial Cells (HAEC): Pregnancy Complicated by Diabetes (PCD) vs. Normoglycemic Pregnancy (NP)
Authors: Szukiewicz Dariusz , Szewczyk Grzegorz , Stangret Aleksandra , Watroba Mateusz 
Published: April 2020

Human beta defensins (HBDs) are small cationic peptides with chemoattractant activities. HBD2 and HBD3 are generally expressed at low levels in physiologic conditions and are induced in response to microbial challenge (e.g. LPS), whereas HBD1 low expression is constitutive, with little regulation in response to infection or other stimuli. HBDs produced by HAEC co‐create an innate antimicrobial immune response in the materno‐placento‐fetal unit. PCD increases the risk of infection. According to recent studies, PCD activates the innate immune response through TLR5 or TLR1/2 on neonatal monocyte, but the data about HBDs are still lacking. The aim of this study was to examine comparatively the effect of resveratrol on SIRT1 level and HBD2 and HBD3 production in HAEC isolated after PCD (White’s class C) vs. NP. HAEC were isolated from the amnion immediately after cesarean section delivery terminating PCD (N = 24, group I) and NP (N = 24, group II) using trypsin‐based method and cultured in vitro under normoxia at 37 degrees C. Upon reaching confluence, HAEC were cultured in media supplemented with 0.5 μM resveratrol and SIRT1 levels were determined in HAEC culture lysates obtained once a day for 7 consecutive days. After pretreatment with LPS (1 μg/mL), HBD2 and HBD3 concentrations in the HAEC culture supernatant, obtained in the days 1,3 and 7 of the culture with resveratrol, were assessed in both goups using ELISA. Nonparametric Wilcoxon rank‐sum test was used and the differences between the groups were considered statistically significant if p < 0.05. In both groups resveratrol increased significantly SIRT1 levels in consecutive days. The response was stronger in PCD as compared to NP. Despite of this, observed increase in both HBD2 and HBD3 concentrations were significantly lower in PCD, amounting to 32.8 / 37.7, 45.5 / 42.9 and 55.3% / 49.5% (HBD2 / HBD3 days 1,3 and 7, respectively) of the values obtained in group II (NP). Importantly, the mean viability of cells in both groups did not differ significantly at the consecutive time points. Thus, susceptibility to infections in diabetes may be to some extent caused by compromised HBDs‐dependent antimicrobial immune respose. The nature of impaired SIRT1 – HBDs interaction is still under investigation.Support or Funding InformationWUM grant: 2M2‐W2‐18/2M2‐W1‐19