Recent Research Articles from UNTHSC

Syndicate content NCBI pubmed
NCBI: db=pubmed; Term="University of North Texas Health Science Center"[All Fields] OR "Univ. of North Texas Health Science Center"[All Fields] OR "UNT Health Science Center"[All Fields] OR "Osteopathic Research Center"[All Fields] OR "University of North Texas System College of Pharmacy"[All Fields] OR "UNT System College of Pharmacy"[All Fields] OR "College of Pharmacy, University of North Texas System"[All Fields]
Updated: 2 hours 31 min ago

mitoSAVE: mitochondrial sequence analysis of variants in Excel.

Wed, 04/08/2015 - 7:29am
Related Articles

mitoSAVE: mitochondrial sequence analysis of variants in Excel.

Forensic Sci Int Genet. 2014 Sep;12:122-5

Authors: King JL, Sajantila A, Budowle B

Abstract
The mitochondrial genome (mtGenome) contains genetic information amenable to numerous applications such as medical research, population and evolutionary studies, and human identity testing. However, inconsistent nomenclature assignment makes haplotype comparison difficult and can lead to false exclusion of potentially useful profiles. Massively Parallel Sequencing (MPS) is a platform for sequencing large datasets and potentially whole populations with relative ease. However, the data generated are not easily parsed and interpreted. With this in mind, mitoSAVE has been developed to enable fast conversion of Variant Call Format (VCF) files. mitoSAVE is an Excel-based workbook that converts data within the VCF into mtDNA haplotypes using phylogenetically-established nomenclature as well as rule-based alignments consistent with current forensic standards. mitoSAVE is formatted for human mitochondrial genome; however, it can easily be adapted to support other reasonably small genomes.

PMID: 24952129 [PubMed - indexed for MEDLINE]

Genetic and linguistic correlation of the Kra-Dai-speaking groups in Thailand.

Sat, 04/04/2015 - 3:30am

Genetic and linguistic correlation of the Kra-Dai-speaking groups in Thailand.

J Hum Genet. 2015 Apr 2;

Authors: Srithawong S, Srikummool M, Pittayaporn P, Ghirotto S, Chantawannakul P, Sun J, Eisenberg A, Chakraborty R, Kutanan W

Abstract
The Kra-Dai linguistic family includes Thai and Lao as well as a great number of languages spoken by ethnic minorities in Southeast Asia. In Thailand, a dozen of other Kra-Dai languages are spoken in addition to Thai, the national language. The genetic structure of the Kra-Dai-speaking populations in Thailand has been studied extensively using uniparentally inherited markers. To extend this line of genetic investigation, this study used 15 autosomal microsatellites of 500 individuals from 11 populations, belonging to nine Kra-Dai ethnicities, namely, the Kaleung, Phu Thai, Saek, Nyo, Lao Isan, Yuan, Black Tai, Phuan and Lue. These ethnolinguistic groups are dispersed in three different geographic regions of Thailand, that is, Northern, Northeastern and Central. The results show a very low average of pairwised Fst (0.0099), as well as no population substructure based on STRUCTURE analysis, indicating genetic homogeneity within the Kra-Dai-speaking group, possibly owing to shared linguistic ancestry. The Mantel test, an analysis of molecular variance, and the approximate Bayesian computation procedure employed to evaluate potential factors for driving genetic diversity revealed that language is the predominant factor affecting genetic variations, whereas geography is not. The result of distance-based clustering analyses and spatial analysis of molecular variance revealed genetic distinctions of some populations, reflecting the effects of genetic drift and gene flow on allele frequency within populations, in concordance with the result of R-matrix regression. The genetic and linguistic affiliations of the contemporary Kra-Dai-speaking groups are consistent with each other despite certain deviation due to various evolutionary factors that may have occurred during their migrations and resettlements.Journal of Human Genetics advance online publication, 2 April 2015; doi:10.1038/jhg.2015.32.

PMID: 25833471 [PubMed - as supplied by publisher]

Amiloride and GMQ allosteric modulation of the GABA-A ρ1 receptor: influences of the intersubunit site.

Fri, 04/03/2015 - 3:29am

Amiloride and GMQ allosteric modulation of the GABA-A ρ1 receptor: influences of the intersubunit site.

J Pharmacol Exp Ther. 2015 Mar 31;

Authors: Snell HD, Gonzales EB

Abstract
Amiloride, a diuretic used in the treatment of hypertension and congestive heart failure, and 2-guanidine-4-methylquinazoline (GMQ), are guanidine compounds that modulate acid-sensing ion channels. Both compounds have demonstrated affinity for a variety of membrane proteins, including members of the Cys-loop family of ligand-gated ion channels, such as the heteromeric GABA-A αβγ receptors. The actions of these guanidine compounds on the homomeric GABA-A ρ1 receptor remains unclear, especially in light of how many GABA-A αβγ receptor modulators have different effects in the GABA-A ρ1 receptors. We sought to characterize the influence of amiloride and 2-guanidine-4-methyquinazoline (GMQ) on the human GABA-A ρ1 receptors using whole-cell patch clamp electrophysiology. The diuretic amiloride potentiated the human GABA-A ρ1 GABA-mediated current, while GMQ antagonized the receptor. Furthermore, a GABA-A second transmembrane domain site, the intersubunit site, responsible for allosteric modulation in the heteromeric GABA-A receptors, mediated amiloride's positive allosteric actions. In contrast, the mutation did not remove GMQ antagonism but only changed the guanidine compound's potency within the human GABA-A ρ1 receptor. Through modeling and introduction of point mutations, we propose that the GABA-A ρ1 intersubunit site plays a role in mediating the allosteric effects of amiloride and GMQ.

PMID: 25829529 [PubMed - as supplied by publisher]

Neuronal injury from cardiac arrest: aging years in minutes.

Thu, 04/02/2015 - 3:29am
Related Articles

Neuronal injury from cardiac arrest: aging years in minutes.

Age (Dordr). 2014;36(4):9680

Authors: Cherry BH, Sumien N, Mallet RT

Abstract
Cardiac arrest is a leading cause of death and permanent disability. Most victims succumb to the oxidative and inflammatory damage sustained during cardiac arrest/resuscitation, but even survivors typically battle long-term neurocognitive impairment. Although extensive research has delineated the complex mechanisms that culminate in neuronal damage and death, no effective treatments have been developed to interrupt these mechanisms. Of importance, many of these injury cascades are also active in the aging brain, where neurons and other cells are under persistent oxidative and inflammatory stress which eventually damages or kills the cells. In light of these similarities, it is reasonable to propose that the brain essentially ages the equivalent of several years within the few minutes taken to resuscitate a patient from cardiac arrest. Accordingly, cardiac arrest-resuscitation models may afford an opportunity to study the deleterious mechanisms underlying the aging process, on an accelerated time course. The aging and resuscitation fields both stand to gain pivotal insights from one another regarding the mechanisms of injury sustained during resuscitation from cardiac arrest and during aging. This synergism between the two fields could be harnessed to foster development of treatments to not only save lives but also to enhance the quality of life for the elderly.

PMID: 25104136 [PubMed - indexed for MEDLINE]

ERK5/KLF4 signaling as a common mediator of the neuroprotective effects of both nerve growth factor and hydrogen peroxide preconditioning.

Thu, 04/02/2015 - 3:29am
Related Articles

ERK5/KLF4 signaling as a common mediator of the neuroprotective effects of both nerve growth factor and hydrogen peroxide preconditioning.

Age (Dordr). 2014;36(4):9685

Authors: Su C, Sun F, Cunningham RL, Rybalchenko N, Singh M

Abstract
Oxidative stress has long been implicated in the pathogenesis of various neurodegenerative disorders such as Alzheimer's disease and stroke. While high levels of oxidative stress are generally associated with cell death, a slight rise of reactive oxygen species (ROS) levels can be protective by "preconditioning" cells to develop a resistance against subsequent challenges. However, the mechanisms underlying such preconditioning (PC)-induced protection are still poorly understood. Previous studies have supported a role of ERK5 (mitogen-activated protein [MAP] kinase 5) in neuroprotection and ischemic tolerance in the hippocampus. In agreement with these findings, our data suggest that ERK5 mediates both hydrogen peroxide (H2O2)-induced PC as well as nerve growth factor (NGF)-induced neuroprotection. Activation of ERK5 partially rescued pheochromocytoma PC12 cells as well as primary hippocampal neurons from H2O2-caused death, while inhibition of ERK5 abolished NGF or PC-induced protection. These results implicate ERK5 signaling as a common downstream pathway for NGF and PC. Furthermore, both NGF and PC increased the expression of the transcription factor, KLF4, which can initiate an anti-apoptotic response in various cell types. Induction of KLF4 by NGF or PC was blocked by siERK5, suggesting that ERK5 is required in this process. siKLF4 can also attenuate NGF- or PC-induced neuroprotection. Overexpression of active MEK5 or KLF4 in H2O2-stressed cells increased Bcl-2/Bax ratio and the expression of NAIP (neuronal apoptosis inhibitory protein). Taken together, our data suggest that ERK5/KLF4 cascade is a common signaling pathway shared by at least two important mechanisms by which neurons can be protected from cell death.

PMID: 25015774 [PubMed - indexed for MEDLINE]

Cerebral palsy of the elbow and forearm.

Thu, 04/02/2015 - 3:29am
Related Articles

Cerebral palsy of the elbow and forearm.

J Hand Surg Am. 2014 Jul;39(7):1425-32

Authors: Bunata R, Icenogle K

Abstract
Management of elbow and forearm involvement in cerebral palsy has evolved over the last 3 decades with a better understanding of its neuropathophysiology, improved outcome measures, and evolving therapy protocols. Current nonoperative and surgical treatment methods are discussed. The use of standard function measuring instruments and encouragement of the participation in research will hopefully result in more accurate outcome information and, thereby, refine our techniques and rehabilitation methods.

PMID: 24969499 [PubMed - indexed for MEDLINE]

Interaction of astrocytes and T cells in physiological and pathological conditions.

Wed, 04/01/2015 - 3:29am

Interaction of astrocytes and T cells in physiological and pathological conditions.

Brain Res. 2015 Mar 23;

Authors: Xie L, Yang SH

Abstract
The central nervous system (CNS) has long been recognized as a site of 'immune privilege' because of the existence of the blood brain barrier (BBB) which presumably isolates CNS from the peripheral immunosurveillance. Different from the peripheral organs, CNS is unique in response to all forms of CNS injury and disease which is mainly mediated by resident microglia and astrocyte. There is increasing evidence that immune cells are not only involved in neuroinflammation process but also the maintenance of CNS homeostasis. T cells, an important immune cell population, are involved in the pathogenesis of some neurological diseases by inducing either innate or adaptive immune responses. Astrocytes, which are the most abundant cell type in the CNS, maintain the integrity of BBB and actively participate in the initiation and progression of neurological diseases. Surprisingly, how astrocytes and T cells interact and the consequences of their interaction are not clear. In this review we briefly summarized T cells diversity and astrocyte function. Then, we examined the evidence for the astrocytes and T cells interaction under physiological and pathological conditions including ischemic stroke, multiple sclerosis, viral infection, and Alzheimer's disease. This article is part of a Special Issue entitled SI: Cell Interactions In Stroke.

PMID: 25813828 [PubMed - as supplied by publisher]

Pulmonary arterial hypertension in adults: novel drugs and catheter ablation techniques show promise? Systematic review on pharmacotherapy and interventional strategies.

Wed, 04/01/2015 - 3:29am
Related Articles

Pulmonary arterial hypertension in adults: novel drugs and catheter ablation techniques show promise? Systematic review on pharmacotherapy and interventional strategies.

Biomed Res Int. 2014;2014:743868

Authors: Rosanio S, Pelliccia F, Gaudio C, Greco C, Keylani AM, D'Agostino DC

Abstract
This systematic review aims to provide an update on pharmacological and interventional strategies for the treatment of pulmonary arterial hypertension in adults. Currently US Food and Drug Administration approved drugs including prostanoids, endothelin-receptor antagonists, phosphodiesterase type-5 inhibitors, and soluble guanylate-cyclase stimulators. These agents have transformed the prognosis for pulmonary arterial hypertension patients from symptomatic improvements in exercise tolerance ten years ago to delayed disease progression today. On the other hand, percutaneous balloon atrioseptostomy by using radiofrequency perforation, cutting balloon dilatation, or insertion of butterfly stents and pulmonary artery catheter-based denervation, both associated with very low rate of major complications and death, should be considered in combination with specific drugs at an earlier stage rather than late in the progression of pulmonary arterial hypertension and before the occurrence of overt right-sided heart failure.

PMID: 25013799 [PubMed - indexed for MEDLINE]

Hypertrophic cardiomyopathy associated Lys104Glu mutation in the myosin regulatory light chain causes diastolic disturbance in mice.

Wed, 04/01/2015 - 3:29am
Related Articles

Hypertrophic cardiomyopathy associated Lys104Glu mutation in the myosin regulatory light chain causes diastolic disturbance in mice.

J Mol Cell Cardiol. 2014 Sep;74:318-29

Authors: Huang W, Liang J, Kazmierczak K, Muthu P, Duggal D, Farman GP, Sorensen L, Pozios I, Abraham TP, Moore JR, Borejdo J, Szczesna-Cordary D

Abstract
We have examined, for the first time, the effects of the familial hypertrophic cardiomyopathy (HCM)-associated Lys104Glu mutation in the myosin regulatory light chain (RLC). Transgenic mice expressing the Lys104Glu substitution (Tg-MUT) were generated and the results were compared to Tg-WT (wild-type human ventricular RLC) mice. Echocardiography with pulse wave Doppler in 6month-old Tg-MUT showed early signs of diastolic disturbance with significantly reduced E/A transmitral velocities ratio. Invasive hemodynamics in 6month-old Tg-MUT mice also demonstrated a borderline significant prolonged isovolumic relaxation time (Tau) and a tendency for slower rate of pressure decline, suggesting alterations in diastolic function in Tg-MUT. Six month-old mutant animals had no LV hypertrophy; however, at >13months they displayed significant hypertrophy and fibrosis. In skinned papillary muscles from 5 to 6month-old mice a mutation induced reduction in maximal tension and slower muscle relaxation rates were observed. Mutated cross-bridges showed increased rates of binding to the thin filaments and a faster rate of the power stroke. In addition, ~2-fold lower level of RLC phosphorylation was observed in the mutant compared to Tg-WT. In line with the higher mitochondrial content seen in Tg-MUT hearts, the MUT-myosin ATPase activity was significantly higher than WT-myosin, indicating increased energy consumption. In the in vitro motility assay, MUT-myosin produced higher actin sliding velocity under zero load, but the velocity drastically decreased with applied load in the MUT vs. WT myosin. Our results suggest that diastolic disturbance (impaired muscle relaxation, lower E/A) and inefficiency of energy use (reduced contractile force and faster ATP consumption) may underlie the Lys104Glu-mediated HCM phenotype.

PMID: 24992035 [PubMed - indexed for MEDLINE]

Methamphetamine and HIV-1-induced neurotoxicity: role of trace amine associated receptor 1 cAMP signaling in astrocytes.

Wed, 04/01/2015 - 3:29am
Related Articles

Methamphetamine and HIV-1-induced neurotoxicity: role of trace amine associated receptor 1 cAMP signaling in astrocytes.

Neuropharmacology. 2014 Oct;85:499-507

Authors: Cisneros IE, Ghorpade A

Abstract
Methamphetamine (METH) is abused by about 5% of the United States population with approximately 10-15% of human immunodeficiency virus-1 (HIV-1) patients reporting its use. METH abuse accelerates the onset and severity of HIV-associated neurocognitive disorders (HAND) and astrocyte-induced neurotoxicity. METH activates G-protein coupled receptors such as trace amine associated receptor 1 (TAAR1) increasing intracellular cyclic adenosine monophosphate (cAMP) levels in presynaptic cells of monoaminergic systems. In the present study, we investigated the effects of METH and HIV-1 on primary human astrocyte TAAR1 expression, function and glutamate clearance. Our results demonstrate combined conditions increased TAAR1 mRNA levels 7-fold and increased intracellular cAMP levels. METH and beta-phenylethylamine (β-PEA), known TAAR1 agonists, increased intracellular cAMP levels in astrocytes. Further, TAAR1 knockdown significantly reduced intracellular cAMP levels in response to METH/β-PEA, indicating signaling through astrocyte TAAR1. METH±HIV-1 decreased excitatory amino acid transporter-2 (EAAT-2) mRNA and significantly decreased glutamate clearance. RNA interference for TAAR1 prevented METH-mediated decreases in EAAT-2. TAAR1 knockdown significantly increased glutamate clearance, which was further heightened significantly by METH. Moreover, TAAR1 overexpression significantly decreased EAAT-2 levels and glutamate clearance that were further reduced by METH. Taken together, our data show that METH treatment activated TAAR1 leading to intracellular cAMP in human astrocytes and modulated glutamate clearance abilities. Furthermore, molecular alterations in astrocyte TAAR1 levels correspond to changes in astrocyte EAAT-2 levels and function. To our knowledge this is the first report implicating astrocyte TAAR1 as a novel receptor for METH during combined injury in the context of HAND.

PMID: 24950453 [PubMed - indexed for MEDLINE]

Trileaflet Mitral Valve with Three Papillary Muscles Associated with Hypertrophic Cardiomyopathy: A Novel Case.

Tue, 03/31/2015 - 3:30am

Trileaflet Mitral Valve with Three Papillary Muscles Associated with Hypertrophic Cardiomyopathy: A Novel Case.

Echocardiography. 2015 Mar 25;

Authors: Rosanio S, Simonsen CJ, Starwalt J, Keylani AM, Vitarelli A

Abstract
Congenital mitral valve (MV) malformations are uncommon, except for MV prolapse. Despite their infrequency, most of them are well-known and defined entities, such as congenital MV stenosis with two papillary muscles, parachute MV, supravalvular mitral ring, hypoplastic MV, isolated cleft in the anterior and/or posterior leaflets, and double-orifice MV. A trileaflet MV with three separate papillary muscles with concordant atrioventricular and ventricle-arterial connections is exceptionally rare. To the best of the authors' knowledge, it has been reported only once in association with subaortic valvular stenosis. We hereby describe a novel case associated with hypertrophic cardiomyopathy.

PMID: 25809503 [PubMed - as supplied by publisher]

Clinical utility of sequential minimal residual disease measurements in the context of risk-based therapy in childhood acute lymphoblastic leukaemia: a prospective study.

Fri, 03/27/2015 - 3:29am

Clinical utility of sequential minimal residual disease measurements in the context of risk-based therapy in childhood acute lymphoblastic leukaemia: a prospective study.

Lancet Oncol. 2015 Mar 19;

Authors: Pui CH, Pei D, Coustan-Smith E, Jeha S, Cheng C, Bowman WP, Sandlund JT, Ribeiro RC, Rubnitz JE, Inaba H, Bhojwani D, Gruber TA, Leung WH, Downing JR, Evans WE, Relling MV, Campana D

Abstract
BACKGROUND: The level of minimal residual disease during remission induction is the most important prognostic indicator in patients with acute lymphoblastic leukaemia (ALL). We aimed to establish the clinical significance of minimal residual disease in a prospective trial that used sequential minimal residual disease measurements to guide treatment decisions.
METHODS: Between June 7, 2000, and Oct 24, 2007, 498 assessable patients with newly diagnosed ALL were enrolled in a clinical trial at St Jude Children's Research Hospital. We provisionally classified the risk of relapse as low, standard, or high according to patients' baseline clinical and laboratory features. Final risk assignment to establish treatment intensity was based mainly on minimal residual disease levels measured on days 19 and 46 of remission induction, and on week 7 of maintenance treatment. Additional measurements of minimal residual disease were made on weeks 17, 48, and 120 (end of treatment). The primary aim was to establish the association between event-free survival and patients' minimal residual disease levels during remission induction and sequentially post-remission. This trial was registered at ClinicalTrials.gov, number NCT00137111.
FINDINGS: Irrespective of the provisional risk classification, 10-year event-free survival was significantly worse for patients with 1% or greater minimal residual disease levels on day 19 compared with patients with lower minimal residual disease levels (69·2%, 95% CI 49·6-82·4, n=36 vs 95·5%, 91·7-97·5, n=244; p<0·001 for the provisional low-risk group and 65·1%, 50·7-76·2, n=56 vs 82·9%, 75·6-88·2, n=142; p=0·01 for the provisional standard-risk group). 12 patients with provisional low-risk ALL and 1% or higher minimal residual disease levels on day 19 but negative minimal residual disease (<0·01%) on day 46 were treated for standard-risk ALL and had a 10-year event-free survival of 88·9% (43·3-98·4). For the 280 provisional low-risk patients, a minimal residual disease level of less than 1% on day 19 predicted a better outcome, irrespective of the minimal residual disease level on day 46. Of provisional standard-risk patients with minimal residual disease of less than 1% on day 19, the 15 with persistent minimal residual disease on day 46 seemed to have an inferior 10-year event-free survival compared with the 126 with negative minimal residual disease (72·7%, 42·5-88·8 vs 84·0%, 76·3-89·4; p=0·06) after receiving the same post-remission treatment for standard-risk ALL. Of patients attaining negative minimal residual disease status after remission induction, minimal residual disease re-emerged in four of 382 studied on week 7, one of 448 at week 17, and one of 437 at week 48; all but one of these six patients died despite additional treatment. By contrast, relapse occurred in only two of the 11 patients who had decreasing minimal residual disease levels between the end of induction and week 7 of maintenance therapy and were treated with chemotherapy alone.
INTERPRETATION: Minimal residual disease levels during remission induction treatment have important prognostic and therapeutic implications even in the context of minimal residual disease-guided treatment. Sequential minimal residual disease monitoring after remission induction is warranted for patients with detectable minimal residual disease.
FUNDING: National Institutes of Health and American Lebanese Syrian Associated Charities.

PMID: 25800893 [PubMed - as supplied by publisher]

Downregulation of Aquaporin 4 Expression through Extracellular Signal-regulated Kinases1/2 Activation in Cultured Astrocytes Following Scratch-injury.

Fri, 03/27/2015 - 3:29am

Downregulation of Aquaporin 4 Expression through Extracellular Signal-regulated Kinases1/2 Activation in Cultured Astrocytes Following Scratch-injury.

Biomed Environ Sci. 2015 Mar;28(3):199-205

Authors: Shi ZF, Zhao WJ, Xu LX, Dong LP, Yang SH, Yuan F

Abstract
OBJECTIVE: To investigate the role of extracellular signal-regulated kinase1/2 (ERK1/2) pathway in the regulation of aquaporin 4 (AQP4) expression in cultured astrocytes after scratch-injury.
METHODS: The scratch-injury model was produced in cultured astrocytes of rat by a 10-μL plastic pipette tip. The morphological changes of astrocytes and lactate dehydrogenase (LDH) leakages were observed to assess the degree of scratch-injury. AQP4 expression was detected by immunofluorescence staining and Western blot, and phosphorylated-ERK1/2 (p-ERK1/2) expression was determined by Western blot. To explore the effect of ERK1/2 pathway on AQP4 expression in scratch-injured astrocytes, 10 µmol/L U0126 (ERK1/2 inhibitor) was incubated in the medium at 30 min before the scratch-injury in some groups.
RESULTS: Increases in LDH leakage were observed at 1, 12, and 24 h after scratch-injury, and AQP4 expression was reduced simultaneously. Decrease in AQP4 expression was associated with a significant increase in ERK1/2 activation. Furthermore, pretreatment with U0126 blocked both ERK1/2 activation and decrease in AQP4 expression induced by scratch-injury.
CONCLUSION: These results indicate that ERK1/2 pathway down-regulates AQP4 expression in scratch-injured astrocytes, and ERK1/2 pathway might be a novel therapeutic target in reversing the effects of astrocytes that contribute to traumatic brain edema.

PMID: 25800444 [PubMed - in process]

Chip-based nanoelectrospray ionization with Fourier transform mass spectrometric detection to screen for local anesthetics intended to mask limb sore in walking horses.

Fri, 03/27/2015 - 3:29am

Chip-based nanoelectrospray ionization with Fourier transform mass spectrometric detection to screen for local anesthetics intended to mask limb sore in walking horses.

J Mass Spectrom. 2015 Mar;50(3):533-7

Authors: Szarka S, Prokai L

Abstract
We report a high-throughput chip-based nanoelectrospray ionization method coupled with Fourier transform mass spectrometry to screen for local anesthetics in samples collected by swabbing. These drugs have been used to mask pain on the limbs of walking horses after forbidden practices of soring or physical abuse. Optimized for lidocaine, the method afforded sub-ppm mass accuracy for nine local anesthetics included in the study. From doped cotton swabs, two third and all of the analytes were detected after adding 10 ng and 100 ng of each drug, respectively. Benzocaine and/or lidocaine were found on positive swab samples collected during walking horse competitions. Copyright © 2015 John Wiley & Sons, Ltd.

PMID: 25800188 [PubMed - in process]

Cerebral regulatory T cells restrain microglia/macrophage-mediated inflammatory responses via IL-10.

Fri, 03/27/2015 - 3:29am
Related Articles

Cerebral regulatory T cells restrain microglia/macrophage-mediated inflammatory responses via IL-10.

Eur J Immunol. 2015 Jan;45(1):180-91

Authors: Xie L, Choudhury GR, Winters A, Yang SH, Jin K

Abstract
Forkhead box P3 (Foxp3)(+) regulatory T (Treg) cells maintain the immune tolerance and prevent inflammatory responses in the periphery. However, the presence of Treg cells in the CNS under steady state has not been studied. Here, for the first time, we show a substantial TCRαβ (+) CD4(+) Foxp3(+) T-cell population (cerebral Treg cells) in the rat cerebrum, constituting more than 15% of the cerebral CD4(+) T-cell compartment. Cerebral Treg cells showed an activated/memory phenotype and expressed many Treg-cell signature genes at higher levels than peripheral Treg cells. Consistent with their activated/memory phenotype, cerebral Treg cells robustly restrained the LPS-induced inflammatory responses of brain microglia/macrophages, suggesting a role in maintaining the cerebral homeostasis by inhibiting the neuroinflammation. In addition, brain astrocytes were the helper cells that sustained Foxp3 expression in Treg cells through IL-2/STAT5 signaling, showing that the interaction between astrocytes and Treg cells contributes to the maintenance of Treg-cell identity in the brain. Taken together, our work represents the first study to characterize the phenotypic and functional features of Treg cells in the rat cerebrum. Our data have provided a novel insight for the contribution of Treg cells to the immunosurveillance and immunomodulation in the cerebrum under steady state.

PMID: 25329858 [PubMed - indexed for MEDLINE]

Neuroprotective effects of transcription factor Brn3b in an ocular hypertension rat model of glaucoma.

Fri, 03/27/2015 - 3:29am
Related Articles

Neuroprotective effects of transcription factor Brn3b in an ocular hypertension rat model of glaucoma.

Invest Ophthalmol Vis Sci. 2015 Feb;56(2):893-907

Authors: Stankowska DL, Minton AZ, Rutledge MA, Mueller BH, Phatak NR, He S, Ma HY, Forster MJ, Yorio T, Krishnamoorthy RR

Abstract
PURPOSE: Glaucoma is an optic neuropathy commonly associated with elevated intraocular pressure (IOP), leading to optic nerve head (ONH) cupping, axon loss, and apoptosis of retinal ganglion cells (RGCs), which could ultimately result in blindness. Brn3b is a class-4 POU domain transcription factor that plays a key role in RGC development, axon outgrowth, and pathfinding. Previous studies suggest that a decrease in Brn3b levels occurs in animal models of glaucoma. The goal of this study was to determine if adeno-associated virus (AAV)-directed overexpression of the Brn3b protein could have neuroprotective effects following elevated IOP-mediated neurodegeneration.
METHODS: Intraocular pressure was elevated in one eye of Brown Norway rats (Rattus norvegicus), following which the IOP-elevated eyes were intravitreally injected with AAV constructs encoding either the GFP (rAAV-CMV-GFP and rAAV-hsyn-GFP) or Brn3b (rAAV-CMV-Brn3b and rAAV-hsyn-Brn3b). Retina sections through the ONH were stained for synaptic plasticity markers and neuroprotection was assessed by RGC counts and visual acuity tests.
RESULTS: Adeno-associated virus-mediated expression of the Brn3b protein in IOP-elevated rat eyes promoted an upregulation of growth associated protein-43 (GAP-43), actin binding LIM protein (abLIM) and acetylated α-tubulin (ac-Tuba) both posterior to the ONH and in RGCs. The RGC survival as well as axon integrity score were significantly improved in IOP-elevated rAAV-hsyn-Brn3b-injected rats compared with those of the IOP-elevated rAAV-hsyn-GFP- injected rats. Additionally, intravitreal rAAV-hsyn-Brn3b administration significantly restored the visual optomotor response in IOP-elevated rat eyes.
CONCLUSIONS: Adeno-associated virus-mediated Brn3b protein expression may be a suitable approach for promoting neuroprotection in animal models of glaucoma.

PMID: 25587060 [PubMed - indexed for MEDLINE]

Coupling between arterial pressure, cerebral blood velocity, and cerebral tissue oxygenation with spontaneous and forced oscillations.

Wed, 03/25/2015 - 3:29am

Coupling between arterial pressure, cerebral blood velocity, and cerebral tissue oxygenation with spontaneous and forced oscillations.

Physiol Meas. 2015 Mar 23;36(4):785-801

Authors: Rickards CA, Sprick JD, Colby HB, Kay VL, Tzeng YC

Abstract
We tested the hypothesis that transmission of arterial pressure to brain tissue oxygenation is low under conditions of arterial pressure instability. Two experimental models of hemodynamic instability were used in healthy human volunteers; (1) oscillatory lower body negative pressure (OLBNP) (N = 8; 5 male, 3 female), and; (2) maximal LBNP to presyncope (N = 21; 13 male, 8 female). Mean arterial pressure (MAP), middle cerebral artery velocity (MCAv), and cerebral tissue oxygen saturation (ScO2) were measured non-invasively. For the OLBNP protocol, between 0 and -60 mmHg negative pressure was applied for 20 cycles at 0.05 Hz, then 20 cycles at 0.1 Hz. For the maximal LBNP protocol, progressive 5 min stages of chamber decompression were applied until the onset of presyncope. Spectral power of MAP, mean MCAv, and ScO2 were calculated within the VLF (0.04-0.07 Hz), and LF (0.07-0.2 Hz) ranges, and cross-spectral coherence was calculated for MAP-mean MCAv, MAP-ScO2, and mean MCAv-ScO2 at baseline, during each OLBNP protocol, and at the level prior to pre-syncope during maximal LBNP (sub-max). The key findings are (1) both 0.1 Hz OLBNP and sub-max LBNP elicited increases in LF power for MAP, mean MCAv, and ScO2 (p ≤ 0.08); (2) 0.05 Hz OLBNP increased VLF power in MAP and ScO2 only (p ≤ 0.06); (3) coherence between MAP-mean MCAv was consistently higher (≥0.71) compared with MAP-ScO2, and mean MCAv-ScO2 (≤0.43) during both OLBNP protocols, and sub-max LBNP (p ≤ 0.04). These data indicate high linearity between pressure and cerebral blood flow variations, but reduced linearity between cerebral tissue oxygenation and both arterial pressure and cerebral blood flow. Measuring arterial pressure variability may not always provide adequate information about the downstream effects on cerebral tissue oxygenation, the key end-point of interest for neuronal viability.

PMID: 25798890 [PubMed - as supplied by publisher]

Mortality Hazard and Survival After Tuberculosis Treatment.

Tue, 03/24/2015 - 3:30am

Mortality Hazard and Survival After Tuberculosis Treatment.

Am J Public Health. 2015 Mar 19;:e1-e8

Authors: Miller TL, Wilson FA, Pang JW, Beavers S, Hoger S, Sharnprapai S, Pagaoa M, Katz DJ, Weis SE

Abstract
OBJECTIVES: We compared mortality among tuberculosis (TB) survivors and a similar population.
METHODS: We used local health authority records from 3 US sites to identify 3853 persons who completed adequate treatment of TB and 7282 individuals diagnosed with latent TB infection 1993 to 2002. We then retrospectively observed mortality after 6 to 16 years of observation. We ascertained vital status as of December 31, 2008, using the Centers for Disease Control and Prevention's National Death Index. We analyzed mortality rates, hazards, and associations using Cox regression.
RESULTS: We traced 11 135 individuals over 119 772 person-years of observation. We found more all-cause deaths (20.7% vs 3.1%) among posttreatment TB patients than among the comparison group, an adjusted average excess of 7.6 deaths per 1000 person-years (8.8 vs 1.2; P < .001). Mortality among posttreatment TB patients varied with observable factors such as race, site of disease, HIV status, and birth country.
CONCLUSIONS: Fully treated TB is still associated with substantial mortality risk. Cure as currently understood may be insufficient protection against TB-associated mortality in the years after treatment, and TB prevention may be a valuable opportunity to modify this risk. (Am J Public Health. Published online ahead of print March 19, 2015: e1-e8. doi:10.2105/AJPH.2014.302431).

PMID: 25790407 [PubMed - as supplied by publisher]

Glutaredoxin 1 (Grx1) Protects Human Retinal Pigment Epithelial Cells from Oxidative Damage by Preventing AKT Glutathionylation.

Tue, 03/24/2015 - 3:30am

Glutaredoxin 1 (Grx1) Protects Human Retinal Pigment Epithelial Cells from Oxidative Damage by Preventing AKT Glutathionylation.

Invest Ophthalmol Vis Sci. 2015 Mar 18;

Authors: Liu X, Jann J, Xavier C, Wu H

Abstract
PURPOSE: Glutaredoxin 1 (Grx1) belongs to the oxidoreductase family and is a component of the endogenous antioxidant defense system. However its physiological function remains largely unknown. In this study, we investigated whether and how Grx1 overexpression protects the retinal pigment epithelial (RPE) cells against H2O2-induced apoptosis.
METHODS: Human retinal pigment epithelial (ARPE-19) cells were transfected with either a Grx1-containing plasmid or an empty vector. Primary human RPE cells were transfected with Grx1 siRNA or scrambled siRNA. Cell viability was measured with the WST8 assay. Apoptosis was quantitatively measured by annexin V/propidium iodide (PI) double staining. The level of protein glutathionylation (PSSG) was measured by immunoblotting using anti-PSSG antibody. AKT activation was examined by Western blot. AKT glutathionylation was detected by immunoprecipitation followed by immunoblotting with anti-PSSG antibody.
RESULTS: Grx1 overexpression protected ARPE-19 cells from H2O2-induced cell viability loss. Conversely, Grx1 gene knockdown sensitized primary human RPE cells to H2O2. Assessment of apoptosis indicated that cells transfected with the Grx1-containing plasmid were more resistant to H2O2 with fewer cells undergoing apoptosis as compared to empty vector transfected cells. H2O2-induced PSSG accumulation was also attenuated by Grx1 enrichment. Furthermore, Grx1 overexpression prevented H2O2-induced AKT glutathionylation, resulting in a sustained phospho-AKT elevation in RPE cells.
CONCLUSIONS: Grx1 can protect RPE cells against oxidative stress-induced apoptosis. The mechanism of this protection is associated with its ability to stimulate the phosphorylation of AKT by preventing AKT glutathionylation. Considering Grx1's protective abilities in RPE cells, Grx1 could be a potential pharmacological target for retinal degenerative diseases.

PMID: 25788646 [PubMed - as supplied by publisher]

Store-Operated Ca2+ Channels in Mesangial Cells Inhibit Matrix Protein Expression.

Tue, 03/24/2015 - 3:30am

Store-Operated Ca2+ Channels in Mesangial Cells Inhibit Matrix Protein Expression.

J Am Soc Nephrol. 2015 Mar 18;

Authors: Wu P, Wang Y, Davis ME, Zuckerman JE, Chaudhari S, Begg M, Ma R

Abstract
Accumulation of extracellular matrix derived from glomerular mesangial cells is an early feature of diabetic nephropathy. Ca(2+) signals mediated by store-operated Ca(2+) channels regulate protein production in a variety of cell types. The aim of this study was to determine the effect of store-operated Ca(2+) channels in mesangial cells on extracellular matrix protein expression. In cultured human mesangial cells, activation of store-operated Ca(2+) channels by thapsigargin significantly decreased fibronectin protein expression and collagen IV mRNA expression in a dose-dependent manner. Conversely, inhibition of the channels by 2-aminoethyl diphenylborinate significantly increased the expression of fibronectin and collagen IV. Similarly, overexpression of stromal interacting molecule 1 reduced, but knockdown of calcium release-activated calcium channel protein 1 (Orai1) increased fibronectin protein expression. Furthermore, 2-aminoethyl diphenylborinate significantly augmented angiotensin II-induced fibronectin protein expression, whereas thapsigargin abrogated high glucose- and TGF-β1-stimulated matrix protein expression. In vivo knockdown of Orai1 in mesangial cells of mice using a targeted nanoparticle siRNA delivery system resulted in increased expression of glomerular fibronectin and collagen IV, and mice showed significant mesangial expansion compared with controls. Similarly, in vivo knockdown of stromal interacting molecule 1 in mesangial cells by recombinant adeno-associated virus-encoded shRNA markedly increased collagen IV protein expression in renal cortex and caused mesangial expansion in rats. These results suggest that store-operated Ca(2+) channels in mesangial cells negatively regulate extracellular matrix protein expression in the kidney, which may serve as an endogenous renoprotective mechanism in diabetes.

PMID: 25788524 [PubMed - as supplied by publisher]

Contact Us