bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calorie Restriction without Restricting Vitamins and Minerals Does Not Deteriorate Bones
Authors: Rahman Md Mizanur , Sankaralingam Sowndramalingam 
Published: April 2020

Calorie restriction has a number of health benefits, however is associated with reduction of bone mineral density (BMD). As calcium and vitamin D are considered to be the most essential nutrients for bone health, this study aimed to determine if restriction of vitamins and minerals is the cause of this bone deterioration in calorie‐restricted diet. We hypothesize that calorie restriction without restricting the vitamins and minerals will not reduce bone mineral density in calorie‐restricted mice. To determine the effect of calorie restriction (CR) on bone mineral density, 6‐month‐old C57BL/6 female mice were fed AIN93 diet ad libitum (AL) or 20% CR for 8 months. Mice were divided into 2 groups: 1) Mice fed AL and 2) Mice fed 20% complete calorie restriction (CCR) where vitamins and minerals are also restricted. Mice were scanned with dual energy x‐ray absorptiometry (DXA) at the age of 6 month (baseline), and 14 month (after 8 months of experimental diet) and analyzed for the bone mass. Calorie restricted mice showed a noticeable reduction in BMD as compared to AL fed mice. To determine if long‐term calorie restriction without restricting vitamins and minerals can attenuate this bone deterioration in CCR mice after 8 months of experimental diet. Six‐month‐old C57BL/6 mice were divided into 2 groups: 1) Mice fed AL and 2) Mice fed 20% CCR for 8 months to induce bone loss. Then 20% CCR diet was replaced with 20% CR diet without restricting vitamins and minerals for another 8 months. Interestingly, reduction of BMD seen in CCR fed mice at the age of 14 month was attenuated at the age of 22 month when this group was fed for 8 months with 20% CR diet without restricting vitamins and minerals. In either case (vitamins and mineral restricted or not restricted), muscle mass, and strength were improved in 20% calorie restricted group as compared to AL group as determined by DXA, and wet weight at sacrifice for muscle mass and by rotarod performance test and endurance stress test for muscle strength. These data indicate that 20% CR without compromising vitamin and minerals could be a natural, cost effective and safe optimal dietary regimen that would improve muscle mass and strength without any deleterious effect on bone.Support or Funding InformationNIH NIA K01 KAG034233A and QNRF UREP23‐097‐1‐026
The Cryptococcus neoformans capsule polysaccharide glucuronoxylomannan induces endothelial barrier permeability via the phosphorylation and internalization of VE‐cadherin
Authors: Gandhi Jaani , Jahan Ishrat , Rooklin Rikki , Martinez Luis , Dores Michael Robert 
Published: April 2020

Cryptococcus neoformans is a pathogenic yeast that has been shown to induce meningoencephalitis within immunocompromised individuals. This pathogen contributes to over 220,000 cases of fungal meningitis annually and is a major cause of mortality in patients with HIV in developing countries. C. neoformans sheds the polysaccharide glucuronoxylomannan (GXM) from its cell capsule, allowing the pathogen to evade the host immune systems and enter neuronal tissues. We hypothesize that C. neoformans GXM induces the disruption of the blood‐brain barrier by stimulating the breakdown of the adherens junctions that hold human brain endothelial cells together. Here, we demonstrate that GXM stimulates endothelial barrier permeability. We found that stimulation of human brain endothelial cells with GXM induces the internalization of VE‐cadherin from the plasma membrane, but not lysosomal sorting and degradation of VE‐cadherin. Instead, VE‐cadherin appears to be transiently phosphorylated and sorted to endosomes, suggesting that GXM‐mediated endothelial barrier disruption is reversible. Our current research is focused on identifying the intracellular signaling pathways that regulate VE‐cadherin phosphorylation and internalization in response to GXM exposure.Support or Funding InformationNIH NIAID: 1R01AI145559‐01A1
(E, Z, E)‐GGPP: A Potential Novel Bactericidal Compound
Authors: Poulos Leah , Mann Francis 
Published: April 2020

Mycobacterium tuberculosis (Mtb), a pathogenic Actinobacterium, has infected one quarter of the world’s population, according to the World Health Organization. The standard treatment of Mtb is a regimen of antibiotics, which has resulted in a mutated strain, XDRTb, that is resistant to every known antibiotic. The key to this antibiotic resistance is thought to be the fastidious cell wall. Most bacteria, including Mtb, utilize an isoprenoid glycosyl carrier for transfer of proteoglycan structures to the extracellular side of the membrane; however, unique to Mtb is the flexibility of its isoprenoid metabolism. Mtb synthesizes a carrier composed of 10 stereospecific isoprene units that is produced by elongation of the two‐unit (E)‐GPP by the (Z)‐FPP synthase, Rv1086, to produce (Z,E)‐FPP which then has 35 carbons added in a cis‐orientation by Rv2361c, resulting in (Z8,E)‐decaprenyl diphosphate (DPP). Although this pathway is well characterized, multiple additional isoprenoid synthases are encoded in the Mtb genome, and previous in vitro studies have indicated Rv2361c can utilize multiple alternate substrates. While attempting to understand the apparent flexibility of DPP metabolism, it was observed that heterologous co‐expression of either of the encoded (E,E,E)‐GGPP synthases, Rv0562 or Rv3383c, with Rv1086 in the heterologous host, Escherichia coli (E. coli), results in complete cell death. Computational modeling of both Rv0562 and Rv3383c suggest that both active sites may accept (Z,E)‐FPP as a substrate, and if this is true, the product would be the novel compound (E,Z,E)‐GGPP. Protein purifications of Rv0562 and Rv3383c individually combined with synthetic (Z,E)‐FPP have resulted in the synthesis of the potentially novel terpenoid product, (E,Z,E)‐GGPP. Subsequent coupled assays of Rv0562 or Rv3383c and Rv1086 resulted in higher product formation than the synthetic substrate, suggesting complex formation. Purification of the proposed novel product will be confirmed spectroscopically and has implications for synthesis of a new antibiotic.Support or Funding InformationUniversity of Wisconsin ‐ Parkside College of Natural and Health Sciences’ Summer Undergraduate Research Fellowship and the SC Johnson Integrated Sciences Laboratory
Does the Mu‐Delta Opioid Receptor Heterodimer Repress Akt Kinase to Reduce Opioid Anti‐Nociception?
Authors: Hurtado Kevin , Keresztes Attila , Barker Natalie , Langlais Paul , Streicher John M. 
Published: April 2020

The mu opioid receptor (MOR) and delta opioid receptor (DOR) have been shown to interact in the regulation of pain, opioid side effects, and similar physiology. However, the mechanism of this interaction is still unknown. Limited in vitro and in vivo experiments have suggested that these receptors heterodimerize (MDOR) to regulate pain and opioid response. However, in vivo studies of this receptor complex are very challenging due to the lack of selective tools to study MDOR activity. We thus designed a first‐in‐class MDOR‐selective antagonist named D24M. Using this tool, we found striking evidence suggesting that the MDOR acts as a negative feedback loop, blocking analgesia while enhancing side effects. We performed phosphoproteomic analysis of D24M and/or oxymorphone‐treated CD‐1 mouse brainstems, and found a network of signaling molecules possibly implicated in MDOR function. Among these altered molecules, we found evidence that the kinase Akt was repressed by oxymorphone treatment and restored by D24M co‐treatment, suggesting that Akt repression may be downstream of the MDOR in vivo, and responsible for the blockade of opioid analgesia by this heterodimer. We tested this hypothesis in male and female CD‐1 mice by intracerebroventricular injection of combinations of oxymorphone, D24M, and the selective Akt inhibitor Akt‐i. We found that D24M increased Oxymorphone‐induced anti‐nociception compared to Oxymorphone alone in the tail flick assay, as in our previous studies. We also found that Akt‐i co‐treatment blocked the increase in anti‐nociception caused by D24M in male, but not female mice. These results suggest that Akt may be repressed in a sex‐specific manner by the MDOR to repress opioid anti‐nociception as part of an anti‐opioid negative feedback loop. These results also suggest that MDOR‐selective antagonists could be novel therapeutics to enhance opioid efficacy while decreasing side effects.Support or Funding InformationFunding InformationThese studies were funded by NIH R21DA044509 and UG3DA047717 to JMS. The authors have no relevant conflicts of interest to declare.
Baroreflex Resetting of Sympathetic Action Potential Subpopulations During Fatiguing Isometric Handgrip and Post‐Exercise Circulatory Occlusion
Authors: Klassen Stephen A. , Badrov Mark B. , Moir M. Erin , Shoemaker J. Kevin 
Published: April 2020

The arterial baroreflex exerts heterogeneous control over the varying‐sized action potential (AP) subpopulations active within human muscle sympathetic nerve activity (MSNA) under baseline conditions. How baroreflex control of sympathetic AP discharge becomes reset to facilitate sympathoexcitation during physical exercise remains to be investigated. Therefore, we quantified the baroreflex gain for each sympathetic AP cluster (i.e., reflecting different c‐fibres) within the MSNA filtered neurogram (microneurography and continuous wavelet transform) during baseline conditions (BSL), the last 2‐min of a 5‐min fatiguing isometric handgrip (20% of max; IHG), and during post‐exercise circulatory occlusion (PECO) in six healthy young participants (3 females, 23–31 years). Baroreflex gain was measured as the slope of the linear function between AP probability (%) versus diastolic blood pressure (DBP; Finometer). We classified AP clusters based on peak‐to‐peak amplitude using the following allocations: small (clusters 1–2), medium (clusters 3–8) and large (clusters 9–15). During BSL, medium AP clusters (e.g., cluster 3: −9.4 ± 2.7 %/mmHg) expressed the greatest baroreflex gains while small (e.g., cluster 1: −1.9 ± 0.4 %/mmHg) and large (e.g., cluster 9: −2.4 ± 0.9 %/mmHg) clusters expressed lesser gains (both P < 0.05 vs. cluster 3). Compared to BSL, baroreflex functions for most AP clusters during IHG and PECO were reset upwards to greater firing probabilities (both Condition‐by‐Cluster Interactions: P < 0.05) and rightwards to higher DBP (BSL: 69 ± 4, IHG: 81 ± 3, PECO: 79 ± 2 mmHg; both P < 0.05 vs. BSL). However, compared to BSL, the gains of the AP cluster baroreflex functions remained unchanged with IHG (e.g., cluster 1: −1.6 ± 0.4, cluster 3: −8.2 ± 2.9, cluster 9: −4.3 ± 1.8 %/mmHg, Main Effect: P > 0.05). Nonetheless, AP cluster gains were augmented above BSL during PECO (e.g., cluster 1: −2.6 ± 1.0, cluster 3: −16.0 ± 4.4, cluster 9: −5.5 ± 1.8 %/mmHg; Main Effect: P < 0.05). IHG (e.g., cluster 15: −1.6 ± 0.5 %/mmHg) and PECO (e.g., cluster 15: −0.6 ± 0.3 %/mmHg) recruited a subpopulation of previously silent larger and faster conducting APs that expressed weak baroreflex gains. These data suggest that during fatiguing isometric handgrip exercise the interaction between the central command feature and the skeletal muscle metaboreflex resets baroreflex control of discrete AP subpopulations to higher blood pressures and greater levels of discharge. In addition to resetting the baroreflex functions, independent activation of the muscle metaboreflex augments the strength of baroreflex control over subpopulations of previously active APs.Support or Funding InformationSupported by the Natural Sciences and Engineering Research Council (NSERC) of Canada.
Does Teaching an Etymological Dissection Tool Aid Student Understanding and Retention of Terminology?
Authors: Mohr Madison , Olive Elizabeth , Barremkala Mallikarjuna , Browne Berkley , Venuti Judith 
Published: April 2020

Based on the premise that teaching a person a useful skill is ultimately more beneficial than filling a temporary need, we developed a tool for medical students to learn new terminology in embryology. This tool, the etymological dissection approach (EDA), dissects new words using their etymological origins. The goal is to provide students with a tool they can apply, not only for the improved understanding of embryological terminology, but medical terminology in general.After IRB approval (IRB# 1201615‐1), data was obtained from class of 2021 focus groups (Phase I), which guided the development of content, timing, and mode of delivery of an EDA resource for the incoming class of 2023. The data recommended newly admitted students be provided with a pre‐matriculation worksheet and a “hands on” workshop early in their first semester to walk them step‐by‐step through the EDA.In Phase II, we created and delivered a pre‐matriculation EDA worksheet that provided an introduction to word parts and a list of commonly encountered word roots, suffixes and prefixes. This was provided to all incoming students via the Student Academic Success Website. Students were also invited to complete a survey that asked their background in embryology, primary and secondary languages, etc. At the end of the first week of classes, a hands‐on workshop was delivered consisting of EDA exercises outlining the 5 steps for “dissecting” each new term: Connect, Deduce, Confirm, Understand, and Integrate. The exercises were also provided to students via the Academic Success Website, whether they attended the workshop or not. Students were encouraged to use the tool and, at the end of their first semester, complete a survey.Data from the pre‐survey revealed students had little to no prior embryology knowledge (2.323 std. dev. +/− 0.989; 1 = no knowledge; 5 = extremely knowledgeable); only 7% have taken an embryology course and 15% a developmental biology course. While 55% of students reported they were moderate to fluent in Spanish, they reported little to no familiarity with Greek (99%) and or Latin (93%). Interestingly, students reported they sometimes (2.327 std. dev. +/− 1.203; 1 = never; 5 = always) attempt to understand terminology using a technique similar to the EDA, perhaps because 17% have taken a medical terminology course. Those students that reviewed the EDA worksheet prior to the workshop, found it to be moderately useful (3.051 std. dev. +/− 0.972; 1 = not at all useful; 5 = extremely useful).The goal of the post‐survey is to determine if students attended the workshop, found it useful, used the EDA during the semester, and if the EDA technique was efficacious in guiding their understanding and retention of terminology. It is hoped that the EDA will add to a medical student’s skillset and provide a tool that can be used throughout a career requiring life‐long learning.
A Novel Distal Convoluted Tubule‐Specific Tamoxifen‐Inducible Cre‐Recombinase Driven by the NaCl Cotransporter Gene
Authors: Cornelius Ryan J. , Sharma Avika , Su Xiao-Tong , McMahon Andrew P. , Ellison David H. , McCormick James A. 
Published: April 2020

The use of knockout and transgenic mouse models coupled with Cre‐lox technologies has revolutionized research in kidney transport physiology by allowing site‐specific genetic recombination in individual nephron segments. Although several groups have tried to generate a distal convoluted tubule (DCT)‐specific mouse Cre‐recombinase driven by the thiazide‐sensitive NaCl cotransporter (NCC) promoter, this goal has remained elusive. The DCT is a major site for the regulation of Na+ and K+ transport. The segment consists of two distinct segments the early (DCT1) and late (DCT2) DCT. The only previously recognized mouse model available allowing targeted gene modification in the DCT is the DCT1‐specific mouse with Cre‐recombinase under control of the Pvalb gene encoding parvalbumin. The model, however, has limitations including activity in neurons that prevent comprehensive characterization of transport pathways in the DCT. Recently, a novel mouse line expressing estrogen‐inducible DCT‐specific Cre was generated and donated to Jackson Laboratory. CRISPR/Cas9 was used to introduce Cre‐ERT2 into the 3' UTR near the stop codon of the Slc12a3 gene encoding NCC (NCC‐Cre‐ERT2 mice). Here, we crossed NCC‐Cre‐ERT2 mice with YFP floxed mice to test whether the Cre expression would mimic that of NCC, and to determine whether the construct is ‘leaky’. Without tamoxifen, approximately 6% of NCC positive cells expressed YFP, indicating minimal leakiness. After five days of tamoxifen injection, mice showed YFP expression in almost all NCC positive cells and there was complete overlap of YFP expression in NCC positive cells. Western blotting showed lower NCC abundance in NCC‐Cre‐ERT2 males compared to controls, but female NCC‐Cre‐ERT2 mice NCC abundance was not significantly different from the abundance in control littermates. Despite the difference in NCC abundance in males, abundance of the active phosphorylated form of NCC did not differ. Furthermore, functional analysis of NCC showed no effects on NCC activity in NCC‐Cre‐ERT2 mice. Plasma K+ and Mg2+ concentrations, and thiazide‐sensitive Na+ and K+ excretion did not differ in NCC‐Cre‐ERT2 mice compared to controls. Thus, the NCC‐Cre‐ERT2 mice have high recombination efficiency, minimal leakiness, and complete fidelity in cell‐specificity. Our data show that Cre expression is entirely localized to the DCT and the genetic modification has very mild or no effect on NCC expression and renal function. The NCC‐Cre‐ERT2 mice are the first mice generated with Cre recombinase activity along the entire DCT, and will be a powerful tool to study DCT function.Support or Funding InformationNIH grants DK098141 and DK117903 to JAM. NIH grant DK51496 and VA grant 1I01BX002228‐01A1 to DHE.
Renal Distal Segment‐Specific BMAL1 Regulates Blood Pressure in the Setting of Potassium Depletion
Authors: Crislip Gene Ryan , Douma Lauren G. , Cheng Kit-Yan Ryan , Barral Dominique , Lynch I. Jeanette , Wingo Charles S. , Gumz Michelle L. 
Published: April 2020

IntroductionCircadian clock factors in the kidney influence systemic blood pressure control. BMAL1 is a core mammalian circadian gene responsible for tissue‐specific transcription regulation. Previously, we generated renal distal segment BMAL1 knockout mice (dsBMAL1 KO) that exhibit lower blood pressure compared to control mice (CNTL) in males but not females. Additionally, male dsBMAL1 KO retain less sodium following potassium depletion compared to CNTL, a difference not seen in females.GoalThe goal of this study was to determine if dysregulation of the renin‐angiotensin‐aldosterone system (RAAS) contributes to the sex‐specific solute handling response to potassium depletion and to test the hypothesis that male dsBMAL1 KO display lower blood pressure than CNTL adapted to a potassium deficient diet.MethodsOur mouse model was generated using floxed exon 8 BMAL1 mice crossed with kidney‐specific cadherin Cre+ mice to generate dsBMAL1 KO. Floxed Cre‐littermates were used as CNTL. Arterial blood samples from 14–18 week old male and female mice were collected at noon for basal and 5 days post potassium depletion for serum measurements (0% K, 0.2% Na; N=4–8). Additional male mice were implanted with telemeter devices for 24‐hour monitoring of blood pressure before and during administration of a potassium depleted diet over 5 days (N=7–8). Two‐way ANOVA was used to compare diet and genotype effects within each sex.ResultsSerum angiotensin II levels were unchanged following potassium depletion regardless of genotype or sex. As expected, serum aldosterone levels were lower following potassium depletion compared to baseline in males and females (M: P<0.0001; F: p<0.01), however, there was no difference between genotypes (M: P=0.5; F: P=0.8). Interestingly, potassium depleted males had higher serum aldosterone at midnight compared to noon (P<0.001), however, there was no time difference in females (P=0.8). Following potassium depletion in males, systolic blood pressure significantly decreased in both genotypes (P<0.0001), but a greater decrease over the treatment period was observed in dsBMAL1 compared to CNTL (CNTL: 125±2.4 to 121±1.4; KO: 123±1.7 to 116±1.7 mmHg; PINTERACTION<0.05).ConclusionsBMAL1 in renal distal segments contributes to blood pressure regulation. Potassium depletion decreases blood pressure in this experimental setting with male dsBMAL1 KO demonstrating a greater drop in pressure than CNTL. These data suggest RAAS does not contribute to genotype‐dependent differences seen in blood pressure following potassium depletion.Support or Funding InformationNIH/NIDDK, 1R01DK109570‐01A1; 19POST34450134 AHA Postdoc Fellowship; 5T32HL083810‐10 Postdoc Training Grant, Gatorade Trust through the UF Department of Medicine, North Florida/South Georgia Veterans Health Systems
Palmitic acid induced lncRNA PARAIL regulates inflammation in human monocytes and macrophages
Authors: Tanwar Vinay Singh , Reddy Marpadga A. , Das Sadhan , Amaram Vishnu , Ganguly Rituparna , Stapleton Kenneth , Lanting Linda , Natarajan Rama 
Published: April 2020

Elevated circulating levels of long chain saturated fatty acids such as Palmitic acid (PA) enhances inflammation, metabolic disorders like diabetes and associated complications. Accumulated evidence shows that long non‐coding RNAs (lncRNAs) play key roles in the regulation of inflammation, however, their role in PA‐induced inflammation in monocytes/macrophages is not well known. Strand‐specific RNA‐seq was performed to identify PA‐induced lncRNAs in CD14+ human monocytes. The RNA‐seq results showed that 2624 transcripts including lncRNAs were differentially expressed in PA treated CD14+ human monocytes. Interestingly, PA significantly induced genes associated with inflammatory phenotype. Here we studied a PA‐induced lncRNA RP11‐37B2 located adjacent to RIPK2, which we designated as
PA‐
regulated
anti‐
inflammatory
lncRNA (PARAIL). PARAIL was induced by PA in a time and dose dependent manner with optimal induction by 200 μM PA at 24 h in THP1 monocytes differentiated into macrophages. Analysis of publicly available datasets showed that PARAIL is also upregulated by lipopolysaccharide (LPS) and bacterial infection in human monocytes and macrophages. PARAIL promoter showed binding motif for NF‐kB, and the NF‐κB inhibitor BAY 11‐7082 significantly inhibited PA‐induced expression of PARAIL. Furthermore, PARAIL knockdown with GapmeR antisense oligonucleotides increased pro‐inflammatory cytokines and suppressed anti‐inflammatory chemokines in THP‐1 macrophages. In addition, mouse orthologous Parail was down regulated in peritoneal macrophages from diabetic db/db mice and bone marrow derived macrophages from Apoe−/− mice, a model of accelerated atherosclerosis. Together, these results show that PA‐induces lncRNA PARAIL in human monocytes via NF‐kB activation, and its knockdown elicits pro‐inflammatory phenotype in macrophages. These results suggest that upregulation of PARAIL in the short term by PA and LPS can mediate feedback mechanisms to protect from fatty acid‐induced inflammation associated with metabolic disorders, and this protection is lost during downregulation of PARAIL in chronic disease.Support or Funding InformationThis research work was funded by National Institutes of Health grant NIH R01 DK 065073 to RN.