bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interdependent expression of P2X receptors in the mouse kidney: P2X4‐P2X7 receptor “cross‐talk”
Authors: Birch Rebecca , Scott‐Ward Toby , Tam Frederick W K , Peppiatt‐Wildman Claire M , Unwin Robert J , Wildman Scott S P 
Published: June 2021

In the renal collecting duct (CD), an ionotropic P2X4‐like receptor may act as a luminal Na sensor, regulating ENaC‐mediated Na reabsorption [1]. Several P2X receptor subunits are expressed in the CD and evidence is emerging that P2X4 and P2X7 subunits might interact [2]. P2X7 is also linked to many renal pathologies.Here we determine whether P2X4 and P2X7 interact at the expression level in the CD. Using target‐specific primers, we quantified P2X4, P2X7 (and β‐actin) mRNA levels in mouse kidney and microdissected CD of wild‐type (WT), P2X4−/− and P2X7−/− mice by real‐time RT‐PCR.Expression of P2X4 and, to a lesser extent P2X7 mRNA was readily detected in WT kidney (n=3), whereas P2X4 and P2X7 mRNA levels were <100‐fold lower in P2X4−/− and P2X7−/− mice respectively (n=3). Expression of P2X4 mRNA was reduced in P2X7−/− kidney (P=0.03; n=3), and a substantial decrease in P2X7 mRNA was observed in the CD of P2X4−/− mice (P<0.05; n=3).Our studies indicate that expression levels of P2X4 and P2X7 in the collecting duct are interdependent and suggest a P2X4/7 heteromeric assembly as the luminal Na sensor.Research supported by the Wellcome Trust
Enhanced oxygen transport by perfluorocarbon emulsion mixed with flowing human blood studied in vitro
Authors: Filho Ivo Torres , Pedro Jose Ricardo , Narayanan Srinivasan , Roseff Susan , Nguyen Nguyen , Berger Brian , Torres Luciana , Spiess Bruce 
Published: June 2021

Perfluorocarbons (PFC) are compounds with high gas solubility that mixed with sickle cell disease (SCD) blood could potentially help deliver O2 to tissues, possibly compensating for SCD red blood cell's lower O2 affinity. PFC have also been suggested as adjunct therapy in certain ischemic conditions. Therefore, an in vitro system was developed for studying O2 transport using blood from 9 SCD patients and 5 healthy donors. The system included a pump, gas mixers, oxygenation and deoxygenation chambers that allowed the flowing blood to reach various levels of hemoglobin O2 saturation (SO2) and O2 partial pressures (PO2) that were measured using a CO‐oximeter and a blood gas analyzer. After addition of PFC emulsion (Oxycyte) (hematocrit = 31%, fluorocrit = 4%), the measurements suggested an increase in the transport of O2 and CO. Addition of PFC resulted in a larger PO2 gradient: from 15 ± 2 mmHg to 23 ± 2 mmHg. Using normal blood, the average O2 extraction ratio (O2ER) after PFC (0.13 ± 0.01) was significantly higher than baseline (0.10 ± 0.01, p<0.004). Using blood from SCD patients, the average O2ER after PFC (0.16 ± 0.01) was also significantly higher than baseline (0.12 ± 0.01, p<0.001). Addition of saline did not cause statistically significant changes. The data suggest increased O2 transport by this PFC emulsion in both normal and SCD blood.Support: Virginia Commonwealth University and Oxygen Biotherapeutics, Inc.
Overexpression of glyoxalase 1 attenuates methylglyoxal‐induced peritoneal injury with suppression of epithelial mesenchymal transition pathway and neovascularization in Wistar rats
Authors: Oba Ikuko , Mori Takefumi , Ohsaki Yusuke , Sato Emiko , Nakamichi Yoshimi , Miyata Toshio , Ito Sadayoshi 
Published: June 2021

Methylglyoxal (MG) is one of the causes of peritoneal injury in peritoneal dialysis. We have previously demonstrated that intraperitoneal administration of MG induced peritoneal fibrosis in Wistar rats, which was reduced in glyoxalase 1 transgenic (GLO1‐Tg) rats. Present study was designed to evaluate the contribution of Epithelial Mesenchymal Transition (EMT) in MG induced peritoneal injury.Twenty ml of 1 mM MG solution was intraperitoneally administered daily to either GLO1‐Tg rats or control Wistar rats for two weeks. Saline was administered as sham group. At the end of the study, liver was removed for immunohistochemical analysis of the peritoneum.α‐SMA, TGF‐β and MMP2 expressions in the peritoneum fibrotic region of Wistar rats compared to those of sham group, which was reduced in GLO1‐Tg rats. Neovascularization determined by Von Willebrand factor staining with increased VEGF expression was observed in the peritoneal fibrotic lesion of MG treated Wistar rats compared to sham group, which was reduced in those of GLO1‐Tg rats. Peritoneal GLO1 expression was increased in GLO1‐Tg rats compared to those of Wistar rats.We conclude that MG induces peritoneal injury with enhanced EMT and neovascularization, which was attenuated by overexpression of GLO1.
Elucidating the Role of a Renal Proximal Tubule‐Specific Olfactory Receptor
Authors: Shepard Blythe D , Cheval Lydie , Doucet Alain , Pluznick Jennifer L 
Published: June 2021

Olfactory receptors (ORs) are seven transmembrane domain G protein‐coupled chemosensors that detect odorants in the nose. We previously reported that OR signaling plays a role in the kidney (PNAS 2009), and to date we have identified 9 renal ORs. One of these is Olfr1393, which is widely expressed in a number of tissues, including kidney (by RT‐PCR screen). Using reverse‐transcribed RNA from microdissected renal segments, we found that Olfr1393 is exclusively expressed in the proximal tubule (PT; S1, S2 and S3). Like the majority of ORs, Olfr1393 is an orphan receptor with no known ligand. To screen for ligands, we cloned this receptor from the kidney and expressed it in HEK293T cells after optimizing conditions to allow for surface expression. We comprehensively screened over 1400 chemicals, and found that Olfr1393 detects cyclic molecules containing either a carbonyl or alcohol group. We also found that when transiently expressed in MDCK cells, Olfr1393 localizes to the apical, not the basolateral PM. To determine the function of this receptor, we generated knockout (KO) mice; the first KO pups were recently born, and they are viable with no overt phenotype. In conclusion, we have shown that Olfr1393 an apically localized, PT‐specific OR which responds to cyclic molecules. Future studies will examine PT function in wild‐type and KO mice to better understand the role that Olfr1393 plays in the kidney.Funding: NIDDK
Sex(y) hormone a‐go‐go: Estrogen–dependent stimulation of hERG potassium channel via G Protein Estrogen Receptor (GPER)
Authors: Gentile Saverio , Lansu Katherine 
Published: June 2021

Female gender is an independent risk factor for several channelopathies. Malfunction of the potassium channel encoded by the human ether a‐go‐go related gene 1 (hERG1) which associates with Long QT type 2 (LQT2) syndromes is more prominent in women. In addition, drug‐induced LQT2 appears to fluctuate during different phases of the menstrual cycle. This raised the question that the steroid sex hormone estrogen (E2) could play a major role in regulating the hERG channel. E2 effects on cell targets have been explained by activation of genomic mechanism; however, a non transcriptional regulation of ion channels might be responsible for sex‐dependent susceptibility to LQT. Interestingly, recent studies have demonstrated that some of the E2's effects on breast cancer cells can be mediated by the newly characterized G protein‐coupled E2 receptor, GPER.In our present study we have characterized a non‐genomic biochemical cascade through which E2 stimulates hERG channel activity. This effect was mediated by GPER and the ser/thr protein kinase PKCalpha via direct phosphorylation of the channel. Ultimately, channel phosphorylation increased hERG membrane stability which determined an augmentation of its current activity. Understanding E2‐dependent regulation of hERG potassium channel can lead to a better understanding of complex physiological mechanisms including heart function and will help to develop better therapeutical strategies for channelopathies.
Microtubule stability is affected by oxidative stress and contributes to lung injury and barrier dysfunction
Authors: Birukova Anna A , Tian Yufeng , Sarich Nicolene , Meliton Angelo 
Published: June 2021

Pathologic activation of redox signaling by inflammatory agents causes endothelial cell (EC) activation and barrier dysfunction. Microtubules (MT) play an important role in the regulation of vascular endothelial permeability, but their impact in modulation of inflammation and EC barrier is not well understood. This study examined effects of LPS‐induced oxidative stress on MT dynamics and involvement of MT in the LPS‐induced mechanisms of Rho GTPase activation, EC permeability and lung injury. LPS treatment of pulmonary vascular EC induced elevation of reactive oxygen species (ROS) and oxidative stress leading to cytoskeletal remodeling, EC hyper‐permeability, increased neutrophil adhesion and activation of inflammatory signaling. LPS also triggered ROS‐dependent disassembly of the microtubule network leading to activation of MT‐dependent signaling. Stabilization of MT or inhibition of MT‐associated Rho‐specific GEF activity suppressed LPS‐induced EC barrier dysfunction in vitro and attenuated vascular leak and lung inflammation in vivo. These studies demonstrate for the first time the mechanism of ROS‐induced Rho activation via destabilization of MT and GEF‐H1‐dependent activation of Rho signaling leading to pulmonary EC barrier dysfunction and exacerbation of LPS‐induced inflammation.Funding: NHLBI HL089257, HL107920
MCPIP‐1 deficiency induces hepatic inflammation and impairs insulin signaling in mice
Authors: CHANG YINGZI , Holdaway Brett Benson , Moody Joshua Dan , Fu Mingui , Kolattukudy Pappachan 
Published: June 2021

Emerging evidence suggests that elevated inflammatory/immune events are associated with pathogenesis of diabetes. MCPIP1 (monocyte chemotactic protein [MCP]–induced protein 1; also known as ZC3H12A), an immune response modifier expressed in mice macrophage in response to LPS and MCP‐1 stimulation, plays a negative role in the process of inflammation. Our current study was designed to test if MCPIP‐1 deficiency induced metabolic dysfunction by affecting the insulin signaling transduction pathway. Wild‐type C57/BL6 mice and MCPIP‐1 knockout mice with the C57/BL6 background were used. We found that MCPIP‐1‐deficient mice showed severe hepatic inflammation and remodeling, lower fasting plasma insulin levels (p<0.05), delayed response to the glucose challenge (p<0.05), and reduced insulin tolerance (p<0.05). Our results also revealed that insulin‐induced phosphorylation of insulin receptor (IR), insulin receptor substrate 1(IRS‐1), and AKT were substantially decreased in the liver from MCPIP1‐deficient mice. In conclusion, MCPIP‐1 deficiency impairs insulin production, insulin signaling transduction, and the ability of enduring metabolic challenges by inducing hepatic inflammation.Funded by Warner's grant, A.T. Still University of Health Sciences.
Can the study of individuals with autonomically complete spinal cord injuries help clarify the role of sympathetic nerves in cerebrovascular reactivity?
Authors: Inskip Jessica , Ravensbergen Rianne H.J.C. , O'Connor Shawn M. , Claydon Victoria E. 
Published: June 2021

Cerebral blood vessels are richly innervated by sympathetic nerves; however, their role in the control of the cerebral vasculature remains controversial. Individuals with spinal cord injury (SCI) provide a unique opportunity to study cerebrovascular control in the absence of sympathetic control. Here we studied cerebrovascular reactivity to CO2 in individuals with cardiovascular autonomically complete and incomplete SCI, and neurologically intact controls. Cardiovascular autonomic completeness was assessed on the basis of supine plasma noradrenaline levels, blood pressure variability and lesion level. Supine beat‐to‐beat blood pressure and middle cerebral artery velocity (MCAv) were continuously recorded, as were breath‐by‐breath partial pressures of end‐tidal O2 and CO2 (PETCO2), during manipulation of PETCO2. Low levels of PETCO2 were obtained by voluntary hyperventilation, and high levels by hypoventilation with increased inspired CO2, during normoxia (controlled on a breath‐by‐breath basis using dynamic end‐tidal forcing). MCAv reactivity was significantly different between groups (control 11.2±2.4; autonomically incomplete SCI 5.8±0.6; autonomically complete SCI 6.2±0.7 %/mmHg, p=0.025, mean±sem). These preliminary data suggest that there is impaired cerebrovascular reactivity in individuals with SCI that is independent of injury to cardiovascular autonomic pathways.This research is supported by the Heart and Stroke Foundation of B.C. and Yukon (V.E.C).
Spinal PKC‐θ activity is required for phrenic long‐term facilitation after acute intermittent hypoxia
Authors: Devinney Michael J , Fields Daryl P , Mitchell Gordon S 
Published: June 2021

Acute intermittent hypoxia (AIH) elicits spinal, serotonin‐dependent long‐term facilitation of phrenic motor output (pLTF). Because the necessary serotonin type 2 receptors are Gq‐coupled metabotropic receptors, we hypothesized that spinal protein kinase C (PKC) activation is necessary for pLTF. PKC inhibitors were delivered intrathecally at C4 in anesthetized, paralyzed, and ventilated rats 5–15 min before AIH. Vehicle‐treated rats exposed to AIH exhibited pLTF (48±3%, P<0.05, n=15) vs. time controls (10±2%, n=21). pLTF was unaffected by the broad spectrum PKC inhibitors NPC‐15437 (NPC; 54±5%, P>;0.05, n=6) or Go 6983 (52±4%, P>;0.05, n=7), but was attenuated by bisindolymalemide I (BIS; 22±6%, P<0.05, n=5). Because BIS is documented to inhibit PKC‐θ, while NPC and Go 6983 are not, we tested a refined hypothesis that pLTF requires PKC‐θ activity. Pretreatment with either sotrastaurin, a broad‐spectrum inhibitor with potent PKC‐θ effects (17±6%, P<0.05, n=4), or a myristolated pseudosubstrate peptide targeting PKC‐θ (10±6%, P<0.05, n=5) attenuated pLTF. Preliminary studies identified PKC‐θ in ventral cervical spinal homogenates via immunoblot; immunofluorescence indicates expression within identified phrenic motor neurons. Thus, PKC‐θ activity is uniquely required for pLTF, a novel insight into mechanisms of AIH‐induced spinal, respiratory plasticity.Supported by NIH HL080209, T32 007654, T32GM007507
Chronic tadalafil treatment ameliorates functional muscle ischemia and exercise‐induced muscle injury in dystrophindeficient mdx mice
Authors: Li Liang , Zepeda Nancy , Victor Ronald G , Thomas Gail D 
Published: June 2021

The dystrophin‐deficient muscles of patients with Duchenne or Becker muscular dystrophy and mdx mice are susceptible to ischemia during exercise due to loss of sarcolemmal neuronal nitric oxide synthase (nNOS). We showed that functional muscle ischemia is alleviated in patients and mice by acute treatment with the phosphodiesterase 5A (PDE5A) inhibitor tadalafil to boost NO‐cGMP signaling in the diseased muscles. We now asked if this anti‐ischemic effect is sustained during chronic PDE5A inhibition. We fed mdx mice control or medicated diets (tadalafil, 4 mg/kg) for 3 months and then evaluated norepinephrine (NE)‐induced hindlimb vasoconstriction. NE evoked similar decreases in femoral vascular conductance (FVC) in resting and contracting hindlimbs of untreated mdx mice, indicating functional muscle ischemia (ΔFVC contraction/rest, 1.07 ± 0.13; n=10). NE‐induced ischemia was attenuated in tadalafil‐treated mice (ΔFVC contraction/rest, 0.61 ± 0.06; n=9; P<0.05 vs untreated) and was similar to C57BL10 controls (ΔFVC contraction/rest, 0.50 ± 0.08; n=10). Serum creatine kinase activity was elevated 6‐fold post‐exercise in untreated mice, but only 2.5‐fold in treated mice (P<0.05). These findings indicate that chronic PDE5A inhibition counteracts functional muscle ischemia in mdx mice, which may reduce injury of the vulnerable dystrophin‐deficient muscles during exercise.Supported by MDA, 158944.
Microbiota and glucocorticoids regulate postnatal developmental of intestinal Fut2 gene expression
Authors: Nanthakumar Nanda N , Meng Di , Newburg David S. 
Published: June 2021

Intestinal maturation is regulated by intrinsic (glucocorticoid) and extrinsic (resident microflora) factors and the goal of this study is to determine the relative contribution of these two regulators in the postnatal development of α1,2‐fucosyltransferase II (Fut2) and sucrase‐isomaltase (SI) gene expression. In conventional raised (CONV) mice, ontogeny of Fut2 and SI gene expression was completed by fourth week. In the absence of colonization in germ‐free (GF) and bacteria‐depleted (BD) mice, intestinal Fut2 expression returned to low suckling levels. Ten days after colonization with adult, but not with suckling, gut microbiome, expression of Fut2 mRNA, α1,2‐fucosyltransferase activity and fucose α1,2‐linked glycoconjugates expression is fully recovered. In the GF mice, the rate of Fut2 and SI ontogeny was significantly delayed. Cortisone acetate (CA) precociously accelerated both Fut2 and SI gene expression in conventionally raised suckling pups. In the GF suckling mice, CA treatment precociously induced development of SI but not Fut2 gene expression. Thus, both microbes and glucocorticoids regulate gut ontogeny, but only suckling gut responds to CA and Fut2 expression remains primarily sensitive to adult microbiome. Complete recovery from mucosal injury caused by DSS‐treatment was observed in the CONV, but not in BD mice. Lack of recovery in BD mice correlated with the level of Fut2 expression in the gut. Thus, colonization by adult microbiota stimulated mature Fut2 gene expression and fucosylated gut phenotype; this colonization‐dependent Fut2 induction is necessary for full recovery from intestinal injury. This may explain the significant association observed between individuals expressing low Fut2 gene expression because of specific Fut2 polymorphic alleles and Crohn's disease and necrotizing enterocolitis.Supported by D059126, HD013021, AI075563, and DK070260.
The New Anatomist: Preparing to Teach in an Integrated Medical Curriculum.
Authors: Sorrentino Gina M. 
Published: June 2021

The recent trend of curriculum integration in undergraduate medical education has resulted in a wide range of curricular designs. Many new graduates in the anatomical sciences receive their doctorate degrees from research‐centered institutions, and the teaching methods of the schools to which they are applying for faculty positions may be quite different and require significant adjustment. With proper guidance, graduates of the anatomical sciences can not only ease their transition into a new institution, but prepare themselves before graduation to take advantage of the job market. The author presents a personal account of the transition from a research‐centered PhD program in Anatomical Sciences to a fully integrated curriculum at a new medical school. Topics discussed here, with relevance to an integrated curriculum in particular, include: understanding the philosophies of the curriculum, understanding the role of anatomy and the anatomy professor, and creating opportunities for educational research in your new institution. Real life examples of how the missions and values of an integrated institution influence teaching are given. This account is aimed at anatomists who are about to graduate or have just graduated, and may be used a guide for degree granting programs in preparing their students for the variety of positions available.Grant Funding Source: N/A
Student perceptions and preferences of two TBL modalities in the second year medical curriculum
Authors: Waggoner Jane Suzanne , Braun Mark W. , O'Loughlin Valerie Dean 
Published: June 2021

Since 2002, team‐based learning (TBL) has been an increasing component of US medical curricula. While numerous studies have examined TBL efficacy in medical curricula, little research has been done comparing differences in TBL modality (implementation and design).This study examines the impact of TBL modality on 2nd year medical students’ perceived learning at Indiana University School of Medicine, Bloomington. Students participated in both medicine TBLs (traditional, standardized TBLs that used assigned groups and graded IRATs and GRATs) and pathology TBLs (nontraditional TBLs that used self‐selected groups and did not have an IRAT/GRAT). At the end of the academic year, students completed an anonymous survey comparing and contrasting the two TBL modalities. The survey contained both quantifiable Likert‐scale questions and open‐ended (qualitative) written comments. The written comments were examined for common theme, using a grounded theory approach.Results showed that students preferred the non‐traditional TBLs to the standardized TBLs. In addition students felt the non‐traditional TBL approach allowed for a greater understanding of material and operated in a more efficient manner. Our research indicates TBL design and implementation impact student perceptions of this curricular tool, which should be taken into account in future TBL design and evaluation.
3D Reconstructions of Early Heart Development as an Educational Resource
Authors: Piet Valerie Marie , Cork Robert John 
Published: June 2021

Three‐dimensional reconstructions are a particularly useful tool for the visualization and understanding of complex subjects like embryo development. Early heart development is one such area. Our work has produced 3D reconstructions of human embryos from Carnegie stages 8, 9 and 10. Working with transverse serial‐sections provided by the Virtual Human Embryo databases we have used the computer programs Amira and Winsurf to produce our 3D reconstructions. Animations generated from these reconstructions are available in pdf form, or online, and can be incorporated into teaching material.The Carnegie staging system divides the embryonic period into 23 stages based on the appearance of notable characteristics. Stages 8, 9, and 10 correspond roughly to 17–23 days of development. During this time period several heart development milestones occur. Beginning at stage 8, angioblastic clusters exist in horseshoe shaped cardiac mesoderm at the cranial end of the embryo. During stage 9, a pericardial cavity is present and by stage 10, an endocardial plexus is coalescing within the myocardium. Our reconstructions include the cardiogenic mesoderm, blood vessel primordia, endothelial tubes, myocardium, epicardium, and doral aorta.The focus on early heart development allows us to visualize the important steps of forming the endothelial tubes and the relative position of the heart primordium in the embryo.Grant Funding Source: NIH HD37811
MedStart: A Hands‐on Anatomical Experience for Middle School Students
Authors: Laitman Benjamin M , Witkin Ariana , Parikh Amar , Armstrong Anne , Zuckerman Samantha , Bhattacharya Romt , Chu Edward , Schneiderman Melissa , Palermo Ann‐Gel , Factor Stephanie H , Reidenberg Joy S , Laitman Jeffrey T 
Published: June 2021

The goal of MedStart, a medical student run, week‐long science education summer camp, is to provide East Harlem middle school students with an appreciation of cardiovascular, pulmonary, and gastrointestinal system disease pathogenesis, treatment and prevention. Introducing students to the anatomical basis of health and disease is a vital component of our program. MedStart takes an interactive approach to education, dividing the camp up into five segments—vital signs, pulmonary, gastrointestinal, cardiovascular, and CPR/first aid—with strong hands‐on components during the organ system‐based days. In the summer of 2012 our program conducted a series of activities in which campers were able to examine manually normal and pathologic human cadaveric hearts, lungs, stomachs, intestines, and livers, in small group sessions led by Mount Sinai School of Medicine medical and graduate students. Campers were given assessments before and after the camp, which, in previous summers, have demonstrated increased knowledge gains in the organ systems we focused on. Along with its other hands‐on activities, MedStart is working to increase health knowledge and empower East Harlem youth to take control of their own health.Grant Funding Source: American Association of Anatomists Educational Outreach Grant