bluuebunny/crossref_metadata_2025_split huggingface dataset:
Remission of nephrotic syndrome resolves plasminogen/plasminuria and reverses the ability of urine to activate ENaC
Authors: Friis Ulla Glenert , Andersen Rene F , Rittig Søren , Buhl Kristian B , Jensen Boye L 
Published: June 2021

Recently it was reported that urinary plasmin activates the epithelial sodium channel (ENaC) and may mediate sodium retention. The present study investigates if remission of nephrotic syndrome (NS) affects glomerular filtration of plasminogen, its activation to plasmin, and the ability of the patients urine to activate ENaC.A paired design study was conducted collecting samples during active nephrotic syndrome and at stable remission. Single cell patch clamp experiments were performed on single collecting duct cells (CDC) with urine samples from six patients investigating the potential to generate an ENaC mediated current.Urine samples from active NS significantly increased the inward current in CDC (201 ± 31%, n=6), whereas at remission, the observed current was significantly lower (29 ± 10%, n=6). The ability of nephrotic urine to enhance inward current was abolished by amiloride (2 μM) (19 ± 10%, n=6).Our data demonstrate significantly increased inward (ENaC) current induced by urine collected during active NS compared to remission, suggesting ENaC inhibition by amiloride to be a new therapeutic target for oedema control.
The good, the bad and the ugly? The role of exercise on obesity‐induced chemerin expression
Authors: Lloyd Jesse William , Owusu Priscilla , Sieburg Michelle , Heckstall Ebony Monique , Kim Yuho , Zerfass Kristy , Keslacy Stefan 
Published: June 2021

Exercise has been shown to alleviate insulin resistance in obesity‐induced diabetes. Although chemerin, a recently discovered adipokine, has been involved in chemotaxis and adipocyte cell‐differentiation in vitro, its role in vivo is still unclear.PurposeTo determine the effect of exercise on obesity‐induced chemerin expression.MethodsForty‐four mice (DIO C57Bl/6J) were separated into 2 cohorts: high fat diet (HFD) n=22 and normal diet (ND) n=22. Following a 12 week‐feeding period, glucose tolerance test was performed with blood samples taken at 0, 30, 60, 90, and 120 min. Chemerin plasma concentration and protein expression were assessed using ELISA and western blot respectively.ResultsHFD induced diabetes. Diabetes resulted in enhanced circulating chemerin levels (ND: 134.63ng/ml vs. HFD: 193.38ng/ml p=0.0009). At 30 min following glucose gavage, circulating chemerin level was significantly higher in HFD compared to ND group (179.6 vs. 112.8 ng/ml respectively P=0.0036). Our preliminary data suggested that exercise upregulated chemerin expression in adipose tissue.ConclusionOur data suggest that exercise regulates diabetes‐increased chemerin expression. A better understanding of chemerin regulation by exercise need to be further studied as it may represent a novel therapeutic target.Study supported by Syracuse University and the School of Education creative writing grant.
Hypertension and Pregnancy are accompanied by differential changes in GABAA and NMDA receptor subunit expression in the hypothalamic Paraventricular Nucleus
Authors: Cork Simon , Chazot Paul , Pyner Susan 
Published: June 2021

Sympathoexcitation is characteristic of cardiovascular disease and pregnancy. Sympathoexcitation emanates, in part, from the hypothalamic paraventricular nucleus (PVN). Hypertensive rats show that the normal balance of GABAergic inhibition and glutamatergic excitation is altered. We hypothesise that this alteration is caused by changes in the subunit composition of the GABAA and NMDA receptors in the PVN. Brains from female Wistars, female spontaneously hypertensive rats (SHR) and pregnant Wistar rats (E19) were subjected to either immunoblotting of PVN micropunches or immunohistochemistry for NMDA and GABAA receptor subunits. Expression of NMDA subunits GluN1, ‐2A and ‐2B was found in all subnuclei of the PVN. A significant increase in expression of the GluN2A subunit was observed in the PVN of SHR (P<0.05 n=3). Furthermore, a significant reduction in GABAA α1 was observed in the PVN of SHR and pregnant animals (P<0.05, n=3). A significant reduction in expression of the GABAA α5 subunits was observed in the PVN of SHR animals (P<0.001 n=3).We hypothesise that the sympathoexcitation observed in pregnancy is driven by a withdrawal in phasic GABAergic inhibition. Conversely, we believe that in SHR, the sympathoexcitation is driven by a decrease in both phasic (α1) and tonic (α5) GABAA‐mediated inhibition, as well as an increase in NMDA‐driven excitation.Work supported by the BBSRC
Depressed serotonin (5‐HT) contributes to suppressed CO2 chemosensitivity in MeCP2 deficient mice
Authors: Toward Marie , Abdala Ana PL , Knopp Sharon J , Paton Julian FR , Bissonnette John M 
Published: June 2021

CO2 chemosensitivity is depressed in methyl‐CpG‐binding protein 2 (MeCP2) deficient mice (a pre‐clinical model of Rett syndrome) at low levels of CO2. This deficiency may contribute to their respiratory disorders. Brain levels of 5‐HT are decreased in MeCP2 null males. We hypothesized that increasing central 5‐HT would restore CO2 chemosensitivity. Studies were preformed in B6.129P2(C)‐Mecp2τm1.1Bird null males (MeCP2−/y), wild type (WT) (MeCP2+/y) and heterozygous females (MeCP−/+). Relative to maximum phrenic (PN) amplitude, WT females studied in situ with 3% CO2 in the perfusate had PN of 54.5± 5.8%. In contrast 5 of 8 MeCP2−/+ were apneic at 3% CO2. CO2 chemosensitivity in null males was determined using body plethysmography and exposing the mouse to sequential 1, 3 and 5% CO2. CO2 gain in MeCP2−/y mice was less than that of MeCP2+/y animals (7.18±0.02 vs 9.82±0.1%) (P=<.0.001). Pre‐treatment with citalopram, a selective 5‐HT reuptake inhibitor (2.5 mg/Kg ip) in MeCP2−/y mice resulted in a significant gain in CO2 chemosensitivity to 10.67±0.25% (P= <0.001). These results suggest that decreased serotonin in MeCP2 deficient mice dis‐facilitates CO2 chemosensitivity.Support: International Rett Syndrome Foundation; Rett Syndrome Research Trust; NewLife Foundation (UK)
The role of Ca2+ and BK channels in the firing rate response of locus coeruleus (LC) neurons to CO2: controlling the chemosensitive gain
Authors: Imber Ann N. , Graham Cathy D. , Putnam Robert W. 
Published: June 2021

Chemosensitive LC neurons increase their firing rate in response to CO2 via inhibition of K+ channels. This increase gets smaller during neonatal development (from P3‐P16). Changes of this K+ channel‐based “accelerating” pathway may account for the developmental changes. We used whole cell patch clamp and fluorescence imaging microscopy to study a different basis for these developmental changes in chemosensitive gain, a “braking” pathway. We found that an L‐type Ca2+ current increased in LC neurons during development. This current was activated by CO2, resulting in increases in [Ca2+]i and the activation of hyperpolarizing Ca2+‐activated K+ currents (KCa), which should reduce the firing rate response of LC neurons to CO2. We used the BK (a large conductance KCa) channel inhibitor paxilline and voltage clamp to study this KCa current. Inhibition of the BK current removed the “brake” and increased the firing rate response to CO2 in LC neurons. Notably, the “braking” pathway increased during neonatal development in a fashion that paralleled the decrease in the chemosensitive firing rate response of LC neurons to CO2. These findings suggest a unique role for Ca2+ in controlling central chemoreceptor gain. Abnormalities in this pathway could be associated with disorders involving elevated central gain, such as sleep apnea and panic disorders.[NIH R01 HL56683, AHA Great Rivers Affiliate Predoctoral Fellowship]
Mitochondrial Content of Carotid Body Type I Cells Decreases During the Maturation of the Hypoxic Response
Authors: Paulet Julia Elizabeth , Tran Huong-Thao , Jordan Heidi , Pye Richard , Ladle David , Wyatt christopher 
Published: June 2021

Carotid body (CB) responses to hypoxia are low at birth and increase over time to mature responses. Using an in vitro rat CB‐carotid sinus nerve (CSN) preparation, Kholwadwala and Donnelly (1992) demonstrated that the CSN activity in response to hypoxia increased from low levels to a robust adult response after two weeks. This time course of maturation was paralleled by an increase in TASK channel sensitivity to hypoxia (Kim et al, 2011). The mechanism(s) which underpin this increase in O2‐sensitivity has not been addressed. However, a body of evidence suggest mitochondria in Type I cells are critical for O2‐sensing by the CB. We tested the hypothesis that changes occur in mitochondrial organization during development of O2‐sensitivity in CBs.Type I cells were isolated from juvenile (4–6 days) and mature rats (14–16 days). Cells were stained with Mitotracker and Celltracker. Total mitochondrial volume in juvenile Type I cells was 100.3 ± 13.6 μm3 (n = 23) and this was significantly smaller in mature cells, 22.6 ± 3.4 μm3 (n = 17, P<0.00003). This decrease in mitochondrial volume was not observed in non‐oxygen sensing cells (superior cervical ganglion cells).These data demonstrate significant reductions in the mitochondrial content of mature Type I cells. This will likely impact the metabolic setting of the cell and may underpin the development of O2‐sensitivity.Supported in part by an NIH grant 1RO1HL091836
Calcium Signaling in Induction of Synaptic Plasticity in Cortical Pyramidal Neurons
Authors: Kalikulov Hodja , Friedlander Michael 
Published: June 2021

Pairing of pre‐ and postsynaptic activity in layer 2/3 pyramidal neurons in visual cortex at a fixed temporal delay results in variable plasticity outcomes (long term synaptic potentiation ‐ LTP, long term synaptic depression ‐ LTD or no significant change ‐ NC). In order to understand the role that intracellular calcium signaling may play in the different outcomes, we measured [Ca2+]i transients during pairing while pharmacologically inhibiting different calcium sources. In control experiments, pre‐postsynaptic pairing resulted in a net LTP but individual cells in the sample underwent either LTD or LTP or NC. Selective inhibition of individual intracellular calcium sources such as IP3 receptors or ryanodine receptors changed the plasticity outcome to a net LTD when RyRs were blocked with 200μM ryanodine while inhibition of IP3 receptors with 1.0 uM xestospongin resulted in a net LTP. Individual [Ca2+]i. Controls had peak transients =430±87 nM and an average decay time constant = 323±44 msec. However, ryanodine treatment reduced the calcium transient peaks to 310±56 nM and reduced the decay time constant to 239±38 msec. Inhibition of IP3 receptors with xestospongin c reduced the peak transient level to 380±62 nM and the decay time constant to 417±55). Thus, the specific and selective mobilization of different intracellular calcium signaling pathways may be one source of the variable plasticity outcomes between cells.Supported by NIH grant EY‐12782 to MJF
A Morpho‐Etiological Work‐Up of Congenital Limb Anomalies
Authors: Tayel Shawky Mahmoud , Ismail Hanaa , Abd Rabuh Abdel Rahman , Tayel Sally , Sallam Hassan , Naguib Kamal 
Published: June 2021

BACKGROUNDLimb anomalies rank behind congenital heart disease as the most common birth defects observed in infants. More than 50 classifications for limb anomalies based on morphology and osseous anatomy have been drafted over the past 150 years. The present work aims to provide a concise summary of the most common congenital limb anomalies on a morpho‐etiological basis.PATIENTS AND METHODSIn a retrospective study, 81 newborns with anomalies of the upper and/or lower limbs were ascertained through clinical examination, chromosomal analysis, skeletal surveys and other relevant investigations.RESULTSFetal causes of limb anomalies represented 75.3% of the cases in the form of 15 cases (18.5%) with chromosomal aberrations (trisomy 13, 18 and 21, duplication 13q and deletion 22q) and 33 cases (40.7%) with single gene disorders. An environmental etiology for limb anomalies was diagnosed in 13 cases (16.1%) as amniotic band disruption, monozygotic twin with abnormal circulation, vascular disruption (Poland sequence, sirenomelia and general vascular disruption) and an infant with a diabetic mother, Twenty cases (24.7%) had limb anomalies as part of sporadic syndromes of unknown etiology.CONCLUSIONSThe morpho‐etiological work‐up of limb anomalies adopted in the present study is valuable for detecting the cause of the anomaly and is crucial for its prevention. Prevention can be achieved by proper genetic counseling, which includes recurrence risk estimation and prenatal diagnosis.
The use of mesenchymal stromal cells improves wound repair in rat abdominal incisions
Authors: Minteer Tanya Elise , Heffner Jeremy , Holmes Jonathan , Ferrari Jonathan , Krontiris-Litowitz Johanna , Marie Hazel , Perko John , Dorion Heath , Fagan Diana 
Published: June 2021

More than 200,000 abdominal hernias are repaired each year. Although new surgical techniques and technologies have attempted to combat the occurrence of hernias, patients continue to suffer from hernias following abdominal surgeries. Regenerative therapy, including the use of bone marrow derived‐mesenchymal stromal cells (MSCs), offers a new avenue to reducing the problem of hernias seen in post‐operative patients. Midline laparotomies were performed on three groups of Lewis rats. Group 1 rats were designated as the control group and were repaired without additives. CollaTape containing platelet‐rich plasma (PRP) was used to repair the abdominal incisions of group 2 rats. The incisions of group 3 rats were repaired similarly to group 2 but with the addition of MSCs. At 4 and 8 weeks postoperative, abdominal fascia was excised (n=7 per group). Collagen deposition and organization (as determined by a Trichrome stain) was rated by blinded observers. Group 3 showed significantly increased neovascularization and collagen deposition compared to the abdominal fascia of groups 1 and 2. The results of this study suggest that the use of MSCs in abdominal repairs could serve as a beneficial tool to improve wound healing.Grant Funding Source : LifeCell Hernia Resident/Fellow Research Grant
Design of bioactive smart nanofilms with bFGF and PDGF‐BB for wound repair
Authors: Challagundla Sukeerth , Mills David K. 
Published: June 2021

Wound healing has become a prominent area of research in regenerative medicine. Although many wound healing and wound dressing techniques have been developed, there remains a great demand for an enhanced treatment modality. Fibroblast Growth Factor (bFGF) and Platelet Derived Growth Factor –BB (PDGF– BB) were incorporated into a polyelectrolyte multilayer nanocoating (PMNs) and applied to a wounded skin equivalent (Epiderm™). The nanocoating consisted of a ten‐layer Poly‐L‐Lysine (PLL) and Poly‐Glutamic‐Acid (PGA) nanocoating with growth factors embedded in two different modalities, a deep layer and double layer. Tissues treated with the designed PMNs enhanced re‐epithelialization, collagen synthesis and the rate of wound healing significantly. The degree of tissue response varied with each nanocoating. The double layer modality showed improved healing compared to the single modalities with an increase in cell number at the wound site with greater proliferation in the epidermis compared to the dermis. Picrosirius Red staining results showed an increase in the level of collagen deposition in the dermis. Controls, with a ten‐layer nanocoating, and no growth factors, showed marginal wound repair. These results suggest that bioactive nanocoatings may have potential as a treatment modality for cutaneous and chronic wounds.Funding provided by the State of Louisiana Governor's Biotechnology Initiative.
Tissue engineering bone by recapitulating developmental and repair programs offers improved biological outcomes
Authors: Bahney Chelsea Shields , Hu Diane , Miclau Theodore , Marcucio Ralph 
Published: June 2021

The principle behind tissue engineering and regenerative medicine is development of functional replacements for damaged or diseased tissues. In the case of bone, technologies focus on promoting direct osteogenesis. However, current therapies are associated with clinical drawbacks, including osteonecrosis and poor integration. Bone regeneration through endochondral ossification, which is the mechanism by which long bones form and the majority of fractures heal, may overcome these problems. We hypothesize that cartilage grafts can promote a vascularized and integrated bone regenerate. To test this, we created stabilized defects in the mid‐diaphysis of the murine tibia and transplanted cartilage grafts from reporter mice. The cartilage was replaced by vascularized bone that integrated with the host. Since endochondral ossification is thought to require chondrocyte apoptosis and cartilage replacement by osteoblasts from the invading vasculature, we predicted the new bone would be host‐derived. However, the new bone was composed largely of donor‐derived cells and there was limited evidence of apoptosis. Together, these data suggest that in our animal model an alternative healing mechanism, such as transdifferentiation, is occurring. Translation of these data into a patient‐based therapy provides a platform to improve clinical outcomes and gain insight into the biology of bone regeneration.Grant Funding Source: NIH‐NIAMS (R01‐AR053645‐01 to TM), UCSF GEMS‐CSTI Fellowship (CSB)
In vitro generated microglia derived from blood precursors
Authors: Etemad Samar , Ruitenberg Marc , Filgueira Luis 
Published: June 2021

Microglia are the macrophages of the central nerve system expressing various markers of the monocyte‐macrophage lineage such as surface molecules, chemokine/cytokine receptors, and displaying corresponding functions, including phagocytosis and antigen presentation. The aim of this study is to establish a new in vitro microglia model using blood‐derived precursor cells.For that purpose, human blood derived monocytes were cultured in the presence of a panel of cytokines and chemokines to generate in vitro microglia. The cells were further characterized for morphological, functional and phenotypic properties and compared with monocytes and in vitro generated dendritic cells. Monocytic lineage marker (CD45, CD14, HLA‐ DR) and chemokine receptors CCR1, CCR2, CCR4, CCR5, CXCR1 and CXCR3 were studied. In vitro generated microglia cells were different from monocytes and dendritic cells in morphology, function and expression of surface markers. In comparison with immature dendritic cells, microglia showed lower capacity in phagocytosing bacteria, antigen presentation and T lymphocyte stimulation.In conclusion, a new protocol for in vitro culture of human microglia cells has been established. Further studies to characterize the microglia at molecular level and use them for functional and toxicity studies are ongoing.Grant Funding Source: School funding
Use of qChIP to identify genes targeted by the Ikaros tumor suppressor
Authors: Payne Jonathon L , Song Chunhua , Ortiz Nathalie Fuentes , Sloane Justin , Payne Kimberly J , Payne Marvin A , Dovat Sinisa 
Published: June 2021

The IKAROS gene encodes a DNA binding zinc finger protein that is essential for hematopoietic differentiation and acts as a tumor suppressor in leukemia. The Ikaros protein is known to both activate and repress target gene expression and to participate in chromatin remodeling. The specific mechanisms by which Ikaros exerts it tumor suppressor activities are unknown. We are using Chromatin Immunoprecipitation (ChIP) assay combined with quantitative PCR (qPCR), called qChIP, to identify genes whose expression is directly regulated by Ikaros. Using this technique we calculate the difference in Ikaros binding to the promoter region of the target genes versus nonspecific binding (control). qChIP assays show that Ikaros binds to the promoter regions of the MYC oncogene, a known Ikaros target, and two other novel target genes. The promoter regions of MYC and the two novel target genes were cloned into luciferase reporter constructs and used to transiently transfect HEK cells that were co‐transfected with Ikaros or empty vector. Luciferase reporter assays showed that Ikaros suppresses the promoter activity of MYC and the two novel target genes. Our data confirm that the MYC oncogene is an Ikaros target and identify two novel Ikaros target genes. These data suggest that Ikaros exerts its tumor suppression function by inhibition of target gene expression in leukemia cells.Supported by R01 HL095120, a St. Baldrick's Foundation Career Development Award, the Four Diamonds Fund of Pennsylvania State University, College of Medicine (to SD), the NIDDK Short‐term Education Program for Under‐Represented Persons (to NFO) and a La Sierra University Dept. of Chemistry and Biochemistry stipend (to JLP).
Blocking ubiquitin deposition at telomeres: the molecular mechanism of TRF2‐mediated end protection
Authors: Okamoto Keiji , Denchi Eros Lazzerini 
Published: June 2021

“End protection” defines that ability of telomeres to cap and protect chromosome ends from the DNA damage response machinery. When end protection is lost, chromosome ends are recognized as sites of DNA lesion and are repaired by the DNA repair machinery resulting in end‐to‐end chromosome fusions, an unstable genomic configuration. The telomere repeat binding factor TRF2 plays a crucial role in this process as shown by the fact that its depletion is sufficient to trigger activation of DNA damage response at chromosome ends. In order to uncover the molecular mechanism employed by TRF2 to protect chromosome ends we performed a screen to identify the critical region within TRF2 involved in end protection. Our data show that a critical mechanism for TRF2‐mediated suppression of DNA damage activation involves suppression of RNF168‐dependent ubiquitination of histone H2A(X). Prevention of this histone modification is both required and sufficient to suppress activation of DNA damage response at chromosome ends. Furthermore, our data reveal a critical role for de‐ubiquitinase enzymes for telomere integrity.ADI
Telomerase activity, HPV presence and splice pattern of hTERT mRNA in cervical intraepithelial neoplasias and adjacent normal tissues
Authors: Skvortsov Dmitry Alexandrovich , Petrenko Anatolii Anatolevich , Korolenkova Lubov Ivanovna , Zvereva Maria Imilievna , Rubtsova Maria Petrovna , Kisseljov Fedor Ljvovich , Dontsova Olga Anatoljevna 
Published: June 2021

Cervical cancers are characterized by the persistence of human papilloma virus (HPV) genome that is found in tissue samples starting from the early stages of tumor progression. Just like in other tumors, the activation of telomerase was observed in cervical carcinomas, but information about its expression was controversial. On model systems (cell lines) alternate splicing of human telomerase reverse transcriptase mRNA may take part in telomerase activity regulation.The aim of this study was to find possible correlations between the presence of HPV sequences, activity of telomerase and expression of different spliced forms of hTERT RNA in cervical intraepithelial neoplasias (CIN). The results show that HPV DNA is present in 60% of normal tissue adjacent to CIN lesions and up to 84% in CIN samples. Telomerase activity was found in 28% of adjacent normal tissue and in 68% of CIN II–III. hTERT RNA that encodes an active enzyme was present almost in all CIN samples. Variations in levels of telomerase activity are presumably not regulated by the splicing forms of hTERT mRNA with deletions.