Recent Research Articles from UNTHSC

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The Impact of APOE Status on Relationship of Biomarkers of Vascular Risk and Systemic Inflammation to Neuropsychiatric Symptoms in Alzheimer's Disease.

Tue, 03/04/2014 - 5:21am

The Impact of APOE Status on Relationship of Biomarkers of Vascular Risk and Systemic Inflammation to Neuropsychiatric Symptoms in Alzheimer's Disease.

J Alzheimers Dis. 2014 Feb 20;

Authors: Hall JR, Wiechmann AR, Johnson LA, Edwards M, Barber RC, Cunningham R, Singh M, O'Bryant SE

Abstract
Research on the link between APOEε4 and neuropsychiatric symptoms (NPS) in Alzheimer's disease (AD) has been inconsistent. Previous work has shown a relationship between serum biomarkers of vascular risk and inflammation and NPS in AD. The current study investigated the impact of APOEε4 status on the relationship between biomarkers of cardiovascular risk, systemic inflammation, and NPS. The sample was drawn from the TARCC Longitudinal Research Cohort; the final sample of 190 consisted of 124 females and 66 males meeting the diagnostic criteria for mild to moderate AD. 115 individuals were APOEε4 carriers and 75 were non-carriers. Serum-based clinical biomarkers of vascular risk and biomarkers of inflammation related to AD were analyzed. NPS data was gathered from caretakers/family members using the Neuropsychiatric Inventory. The significant biomarkers differed for carriers and non-carriers with IL15 being a negative biomarker of total NPS accounting for 12% of the variance for carriers and IL18 and TNFα negative predictors for non-carriers (18% of variance). Patterns related to specific symptoms were similar. Stratification by gender revealed significant biomarkers of total NPS for female carriers were negative IL15 and IL1ra (18% of variance) and for female non-carriers were negative IL18 and positive homocysteine. Total cholesterol was a positive biomarker of total NPS for both male carriers (36% of variance) and non-carriers (negative TNFα and total cholesterol, 32% of variance). These findings suggest that dysregulation of inflammatory activity is related to NPS, that cholesterol is a significant factor in the occurrence of NPS, and that gender and APOE status need to be considered.

PMID: 24577461 [PubMed - as supplied by publisher]

Label-free LC-MS/MS identification of phosphatidylglycerol-regulated proteins in Synechocystis sp. PCC6803.

Sat, 03/01/2014 - 5:23am

Label-free LC-MS/MS identification of phosphatidylglycerol-regulated proteins in Synechocystis sp. PCC6803.

Proteomics. 2014 Feb 26;

Authors: Talamantes T, Ughy B, Domonkos I, Kis M, Gombos Z, Prokai L

Abstract
We present a proteomics dataset combining SDS-PAGE prefractionation and data-dependent LC-MS/MS that enables the identification of phosphatidylglycerol-regulated proteins in the pgsA(-) mutant of Synechocystis sp. PCC6803, a cyanobacterium strain that grows with this indispensable phospholipid added exogenously. We searched the acquired raw data against a composite protein sequence database of Synechocystis using Mascot, and employed Progenesis LC-MS software for label-free quantification based on extracted peptide intensitiesto detect changes in protein abundances upon phospholipid withdrawal. Protein identifications were validated using rigorous criteria, and our analysis of the dataset revealed 80 phosphatidylglycerol-regulated proteins involved in various cellular processes including photosynthesis, respiration, metabolism, transport, transcription, and translation. The data have been deposited to the ProteomeXchange with identifier PXD000363. This article is protected by copyright. All rights reserved.

PMID: 24574175 [PubMed - as supplied by publisher]

Investigation of the bacterial retting community of kenaf (Hibiscus cannabinus) under different conditions using next-generation semiconductor sequencing.

Sat, 03/01/2014 - 5:23am
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Investigation of the bacterial retting community of kenaf (Hibiscus cannabinus) under different conditions using next-generation semiconductor sequencing.

J Ind Microbiol Biotechnol. 2013 May;40(5):465-75

Authors: Visi DK, D'Souza N, Ayre BG, Webber Iii CL, Allen MS

Abstract
The microbial communities associated with kenaf (Hibiscus cannabinus) plant fibers during retting were determined in an effort to identify possible means of accelerating this process for industrial scale-up. Microbial communities were identified by semiconductor sequencing of 16S rRNA gene amplicons from DNA harvested from plant-surface associated samples and analyzed using an Ion Torrent PGM. The communities were sampled after 96 h from each of three different conditions, including amendments with pond water, sterilized pond water, or with a mixture of pectinolytic bacterial isolates. Additionally, plants from two different sources and having different pretreatment conditions were compared. We report that the best retting communities are dominated by members of the order Clostridiales. These bacteria appear to be naturally associated with the plant material, although slight variations between source materials were found. Additionally, heavy inoculations of pectinolytic bacteria established themselves and in addition their presence facilitated the rapid dominance of the original plant-associated Clostridiales. These data suggest that members of the order Clostridiales dominate the community and are most closely associated with efficient and effective retting. The results further suggest that establishment of the community structure is first driven by the switch to anaerobic conditions, and subsequently by possible competition for nitrogen. These findings reveal important bacterial groups involved in fiber retting, and suggest mechanisms for the manipulation of the community and retting efficiency by modifying nutrient availability.

PMID: 23475284 [PubMed - indexed for MEDLINE]

Mineralocorticoid receptor in the NTS stimulates saline intake during fourth ventricular infusions of aldosterone.

Fri, 02/28/2014 - 5:18am
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Mineralocorticoid receptor in the NTS stimulates saline intake during fourth ventricular infusions of aldosterone.

Am J Physiol Regul Integr Comp Physiol. 2014 Jan 1;306(1):R61-6

Authors: Koneru B, Bathina CS, Cherry BH, Mifflin SW

Abstract
The purpose of this study was to determine whether neurons within the nucleus tractus solitarius (NTS) that express the mineralocorticoid receptor (MR) play a role in aldosterone stimulation of salt intake. Adult Wistar-Kyoto (WKY) rats received microinjections into the NTS of a short-hairpin RNA (shRNA) for the MR, to site specifically reduce levels of the MR by RNA interference (shRNA; n = 9) or scrambled RNA as a control (scRNA; n = 8). After injection of the viral construct, aldosterone-filled osmotic minipumps were implanted subcutaneously and connected to a cannula extending into the fourth ventricle to infuse aldosterone at a rate of 25 ng/h. Before and after surgeries, rats had ad libitum access to normal sodium (0.26%) rat chow and two graduated drinking bottles filled with either distilled water or 0.3 M NaCl. Before the surgeries, basal saline intake was 1.6 ± 0.6 ml in the scRNA group and 1.56 ± 0.6 ml in the shRNA group. Twenty-four days postsurgery, saline intake was elevated to a greater extent in the scRNA group (5.9 ± 1.07 ml) than in the shRNA group (2.41 ± 0.6 ml). Post mortem immunohistochemistry revealed a significant reduction in the number of NTS neurons exhibiting immunoreactivity for MR in shRNA-injected rats (23 ± 1 cells/section) versus scRNA-injected rats (33 ± 2 cells/section; P = 0.008). shRNA did not alter the level of 11-β-hydroxysteroid dehydrogenase type II (HSD2) protein in the NTS as judged by the number of HSD2 immunoreactive neurons. These results suggest that fourth ventricular infusions of aldosterone stimulate saline intake, and that this stimulation is at least in part mediated by hindbrain NTS neurons that express MR.

PMID: 24259463 [PubMed - indexed for MEDLINE]

A Pilot Case-Cohort Study of Brain Cancer in Poultry and Control Workers.

Thu, 02/27/2014 - 4:47am

A Pilot Case-Cohort Study of Brain Cancer in Poultry and Control Workers.

Nutr Cancer. 2014 Feb 24;

Authors: Gandhi S, Felini MJ, Ndetan H, Cardarelli K, Jadhav S, Faramawi M, Johnson ES

Abstract
We conducted an exploratory study to investigate which exposures (including poultry oncogenic viruses) are associated with brain cancer in poultry workers. A total of 46,819 workers in poultry and nonpoultry plants from the same union were initially followed for mortality. Brain cancer was observed to be in excess among poultry workers. Here we report on a pilot case-cohort study with cases consisting of 26 (55%) of the 47 brain cancer deaths recorded in the cohort, and controls consisting of a random sample of the cohort (n = 124). Exposure information was obtained from telephone interviews, and brain cancer mortality risk estimated by odds ratios. Increased risk of brain cancer was associated with killing chickens, odds ratio (OR) = 5.8 (95% confidence interval, 1.2-28.3); working in a shell-fish farm, OR = 13.0 (95% CI, 1.9-84.2); and eating uncooked fish, OR = 8.2 (95% CI, 1.8-37.0). Decreased risks were observed for chicken pox illness, OR = 0.2 (95% CI, 0.1-0.6), and measles vaccination, OR = 0.2 (95% CI, 0.1-0.6). Killing chickens, an activity associated with the highest occupational exposure to poultry oncogenic viruses, was associated with brain cancer mortality, as were occupational and dietary shellfish exposures. These findings are novel.

PMID: 24564367 [PubMed - as supplied by publisher]

Toward an improved understanding of the physiology of aqueous humor flow.

Thu, 02/27/2014 - 4:47am
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Toward an improved understanding of the physiology of aqueous humor flow.

Invest Ophthalmol Vis Sci. 2014 Jan;55(1):404

Authors: Millar JC

PMID: 24448440 [PubMed - indexed for MEDLINE]

Comparison of the accuracy of kriging and IDW interpolations in estimating groundwater arsenic concentrations in Texas.

Wed, 02/26/2014 - 5:37am

Comparison of the accuracy of kriging and IDW interpolations in estimating groundwater arsenic concentrations in Texas.

Environ Res. 2014 Feb 19;

Authors: Gong G, Mattevada S, O'Bryant SE

Abstract
Exposure to arsenic causes many diseases. Most Americans in rural areas use groundwater for drinking, which may contain arsenic above the currently allowable level, 10µg/L. It is cost-effective to estimate groundwater arsenic levels based on data from wells with known arsenic concentrations. We compared the accuracy of several commonly used interpolation methods in estimating arsenic concentrations in >8000 wells in Texas by the leave-one-out-cross-validation technique. Correlation coefficient between measured and estimated arsenic levels was greater with inverse distance weighted (IDW) than kriging Gaussian, kriging spherical or cokriging interpolations when analyzing data from wells in the entire Texas (p<0.0001). Correlation coefficient was significantly lower with cokriging than any other methods (p<0.006) for wells in Texas, east Texas or the Edwards aquifer. Correlation coefficient was significantly greater for wells in southwestern Texas Panhandle than in east Texas, and was higher for wells in Ogallala aquifer than in Edwards aquifer (p<0.0001) regardless of interpolation methods. In regression analysis, the best models are when well depth and/or elevation were entered into the model as covariates regardless of area/aquifer or interpolation methods, and models with IDW are better than kriging in any area/aquifer. In conclusion, the accuracy in estimating groundwater arsenic level depends on both interpolation methods and wells' geographic distributions and characteristics in Texas. Taking well depth and elevation into regression analysis as covariates significantly increases the accuracy in estimating groundwater arsenic level in Texas with IDW in particular.

PMID: 24559533 [PubMed - as supplied by publisher]

The structural basis of an NADP(+)-independent dithiol oxidase in FK228 biosynthesis.

Tue, 02/25/2014 - 5:28am

The structural basis of an NADP(+)-independent dithiol oxidase in FK228 biosynthesis.

Sci Rep. 2014;4:4145

Authors: Li J, Wang C, Zhang ZM, Cheng YQ, Zhou J

Abstract
The disulfide bond is unusual in natural products and critical for thermal stability, cell permeability and bioactivity. DepH from Chromobacterium violaceum No. 968 is an FAD-dependent enzyme responsible for catalyzing the disulfide bond formation of FK228, an anticancer prodrug approved for the treatment of cutaneous T-cell lymphoma. Here we report the crystal structures of DepH and DepH complexed with a substrate analogue S,S'-dimethyl FK228 at 1.82 Å and 2.00 Å, respectively. Structural and biochemical analyses revealed that DepH, in contrast to the well characterized low molecular weight thioredoxin reductases (LMW TrxRs), is an NADP(+)-independent dithiol oxidase. DepH not only lacks a conserved GGGDXAXE motif necessary for NADP(+) binding in the canonical LMW TrxRs, but also contains a 11-residue sequence which physically impedes the binding of NADP(+). These observations explain the difference between NADP(+)-independent small molecule dithiol oxidases and NADP(+)-dependent thioredoxin reductases and provide insights for understanding the catalytic mechanism of dithiol oxidases involved in natural product biosynthesis.

PMID: 24553401 [PubMed - as supplied by publisher]

Internal validation of the GlobalFiler™ Express PCR Amplification Kit for the direct amplification of reference DNA samples on a high-throughput automated workflow.

Tue, 02/25/2014 - 5:28am

Internal validation of the GlobalFiler™ Express PCR Amplification Kit for the direct amplification of reference DNA samples on a high-throughput automated workflow.

Forensic Sci Int Genet. 2014 Jan 28;10C:33-39

Authors: Flores S, Sun J, King J, Budowle B

Abstract
The GlobalFiler™ Express PCR Amplification Kit uses 6-dye fluorescent chemistry to enable multiplexing of 21 autosomal STRs, 1 Y-STR, 1 Y-indel and the sex-determining marker amelogenin. The kit is specifically designed for processing reference DNA samples in a high throughput manner. Validation studies were conducted to assess the performance and define the limitations of this direct amplification kit for typing blood and buccal reference DNA samples on various punchable collection media. Studies included thermal cycling sensitivity, reproducibility, precision, sensitivity of detection, minimum detection threshold, system contamination, stochastic threshold and concordance. Results showed that optimal amplification and injection parameters for a 1.2mm punch from blood and buccal samples were 27 and 28 cycles, respectively, combined with a 12s injection on an ABI 3500xL Genetic Analyzer. Minimum detection thresholds were set at 100 and 120RFUs for 27 and 28 cycles, respectively, and it was suggested that data from positive amplification controls provided a better threshold representation. Stochastic thresholds were set at 250 and 400RFUs for 27 and 28 cycles, respectively, as stochastic effects increased with cycle number. The minimum amount of input DNA resulting in a full profile was 0.5ng, however, the optimum range determined was 2.5-10ng. Profile quality from the GlobalFiler™ Express Kit and the previously validated AmpFlSTR(®) Identifiler(®) Direct Kit was comparable. The validation data support that reliable DNA typing results from reference DNA samples can be obtained using the GlobalFiler™ Express PCR Amplification Kit.

PMID: 24552885 [PubMed - as supplied by publisher]

Lens specific RLIP76 transgenic mice show a phenotype similar to microphthalmia.

Fri, 02/21/2014 - 5:24am
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Lens specific RLIP76 transgenic mice show a phenotype similar to microphthalmia.

Exp Eye Res. 2014 Jan;118:125-34

Authors: Sahu M, Sharma R, Yadav S, Wakamiya M, Chaudhary P, Awasthi S, Awasthi YC

Abstract
RALBP1/RLIP76 is a ubiquitously expressed protein, involved in promotion and regulation of functions initiated by Ral and R-Ras small GTPases. Presence of multiple domains in its structure enables RLIP76 to be involved in a number of physiological processes such as endocytosis, exocytosis, mitochondrial fission, actin cytoskeleton remodeling, and transport of exogenous and endogenous toxicants. Previously, we have established that RLIP76 provides protection to ocular tissues against oxidative stress by transporting the glutathione-conjugates of the toxic, electrophilic products of lipid peroxidation generated during oxidative stress. Therefore, we developed lens specific RLIP76 transgenic mice (lensRLIP76 Tg) to elucidate the role of RLIP76 in protection against oxidative stress, but these transgenic mice showed impaired lens development and a phenotype with small eyes similar to that observed in microphthalmia. These findings prompted us to investigate the mechanisms via which RLIP76 affects lens and eye development. In the present study, we report engineering of lensRLIP76 Tg mice, characterization of the associated phenotype, and the possible molecular mechanisms that lead to the impaired development of eye and lens in these mice. The results of microarray array analysis indicate that the genes involved in pathways for G-Protein signaling, actin cytoskeleton reorganization, endocytosis, and apoptosis are affected in these transgenic mice. The expression of transcription factors, Pax6, Hsf1, and Hsf4b known to be involved in lens development is down regulated in the lens of these Tg mice. However, the expression of heat shock proteins (Hsps), the downstream targets of Hsfs, is differentially affected in the lens showing down regulation of Hsp27, Hsp40, up regulation of Hsp60, and no effect on Hsp70 and Hsp90 expression. The disruption in the organization of actin cytoskeleton of these Tg mice was associated with the inhibition of the activation of Cdc42 and down regulation of cofilin phosphorylation. These mice may provide useful animal model for elucidating the mechanisms of lens development, and etiology of microphthalmia.

PMID: 24188744 [PubMed - indexed for MEDLINE]

The therapeutic promise of positive allosteric modulation of nicotinic receptors.

Wed, 02/19/2014 - 5:20am

The therapeutic promise of positive allosteric modulation of nicotinic receptors.

Eur J Pharmacol. 2014 Feb 11;

Authors: Uteshev VV

Abstract
In the central nervous system, deficits in cholinergic neurotransmission correlate with decreased attention and cognitive impairment, while stimulation of neuronal nicotinic acetylcholine receptors improves attention, cognitive performance and neuronal resistance to injury as well as produces robust analgesic and anti-inflammatory effects. The rational basis for the therapeutic use of orthosteric agonists and positive allosteric modulators (PAMs) of nicotinic receptors arises from the finding that functional nicotinic receptors are ubiquitously expressed in neuronal and non-neuronal tissues including brain regions highly vulnerable to traumatic and ischemic types of injury (e.g., cortex and hippocampus). Moreover, functional nicotinic receptors do not vanish in age-, disease- and trauma-related neuropathologies, but their expression and/or activation levels decline in a subunit- and brain region-specific manner. Therefore, augmenting the endogenous cholinergic tone by nicotinic agents is possible and may offset neurological impairments associated with cholinergic hypofunction. Importantly, because neuronal damage elevates extracellular levels of choline (a selective agonist of α7 nicotinic acetylcholine receptors) near the site of injury, α7-PAM-based treatments may augment pathology-activated α7-dependent auto-therapies where and when they are most needed (i.e., in the penumbra, post-injury). Thus, the nicotinic-PAM-based treatments are expected to be highly efficacious with fewer side effects as compared to a more indiscriminate action of exogenous orthosteric agonists. In this review, I will summarize the existing trends in therapeutic applications of nicotinic PAMs.

PMID: 24530419 [PubMed - as supplied by publisher]

Autosomal and Y-STR analysis of degraded DNA from the 120-year-old skeletal remains of Ezekiel Harper.

Wed, 02/19/2014 - 5:20am

Autosomal and Y-STR analysis of degraded DNA from the 120-year-old skeletal remains of Ezekiel Harper.

Forensic Sci Int Genet. 2014 Mar;9C:33-41

Authors: Ambers A, Gill-King H, Dirkmaat D, Benjamin R, King J, Budowle B

Abstract
The 120-year-old skeletal remains of Confederate Civil War soldier Captain Ezekiel "Zeke" Harper were exhumed by court order in January 2011 for DNA analysis. The goal of the DNA testing was to support or refute whether Captain Harper had fathered a son (Earl J. Maxwell) with his Native American maid prior to his murder in 1892. Bones with adequate structural integrity (left tibia, right tibia, right femur, mandible, four teeth) were retrieved from the burial site and sent to the Institute of Applied Genetics in Fort Worth, Texas for analysis. Given the age and condition of the remains, three different extraction methods were used to maximize the probability of DNA recovery. The majority of the DNA isolates from over fifty separate bone sections yielded partial autosomal STR genotypes and partial Y-STR haplotypes. After comparing the partial results for concordance, consensus profiles were generated for comparison to reference samples from alleged family members. Considering the genetic recombination that occurs in autosomal DNA over the generations within a family, Y-STR analysis was determined to be the most appropriate and informative approach for determining potential kinship. Two of Earl J. Maxwell's grandsons submitted buccal samples for comparison. The Y-STR haplotypes obtained from both of these reference samples were identical to each other and to the alleles in Ezekiel Harper's consensus profile at all 17 loci examined. This Y-STR haplotype was not found in either of two major Y-STR population databases (U.S. Y-STR database and YHRD). The fact that the Y-STR haplotype obtained from Ezekiel's skeletal remains and Earl's grandsons is not found in either population database demonstrates its rarity and further supports a paternal lineage relationship among them. Results of the genetic analyses are consistent with the hypothesis that Earl J. Maxwell is the son of Ezekiel Harper.

PMID: 24528577 [PubMed - as supplied by publisher]

Age estimation via quantification of signal-joint T cell receptor excision circles in Koreans.

Tue, 02/18/2014 - 5:22am

Age estimation via quantification of signal-joint T cell receptor excision circles in Koreans.

Leg Med (Tokyo). 2014 Jan 31;

Authors: Cho S, Ge J, Seo SB, Kim K, Lee HY, Lee SD

Abstract
The estimation of age from biological samples (i.e., remains) at crime scenes could provide useful information about both victims and other persons related to criminal activities. Signal-joint T cell receptor excision circle (sjTREC) levels in peripheral blood decline with age, and negative correlations between sjTREC levels and age have been demonstrated in several ethnic groups. To validate the utility of sjTREC for age estimation in Koreans, Taqman qPCR was used to quantify the sjTREC level in samples obtained from 172 individuals ranging from 16 to 65years old. We modified the previously reported method by using a shorter amplicon and confirmed the efficiency and utility of this method in this report. Our results showed that the linear negative regression curve between sjTREC levels and age was characterized by r=-0.807 and a standard error of 8.49years. These results indicate that sjTREC level is an effective age estimation method in Koreans. The value of the standard error of quantification was not different from previous reports for other population groups.

PMID: 24524944 [PubMed - as supplied by publisher]

The Role of TGF-β2 and Bone Morphogenetic Proteins in the Trabecular Meshwork and Glaucoma.

Sat, 02/15/2014 - 5:42am

The Role of TGF-β2 and Bone Morphogenetic Proteins in the Trabecular Meshwork and Glaucoma.

J Ocul Pharmacol Ther. 2014 Feb 11;

Authors: Wordinger RJ, Sharma T, Clark AF

Abstract
Abstract Primary open-angle glaucoma (POAG) is the second leading cause of blindness worldwide. Elevated intraocular pressure (IOP) is a primary risk factor associated with POAG. Increased aqueous humor (AH) outflow resistance through the trabecular meshwork (TM) results in elevated IOP in POAG patients. Resistance to AH outflow is associated with increased accumulation of extracellular matrix (ECM) proteins in the TM. In addition, levels of transforming growth factor-beta2 (TGF-β2) are elevated in the AH and TM tissue of POAG patients. Elevated levels of TGF-β2 in other tissues have been associated with fibrosis and increased tissue stiffness. However, locally produced effectors that maintain homeostatic relationships must also be present. Bone morphogenetic proteins (BMPs) serve this purpose in the TM as they inhibit TGF-β2-induced ECM changes in TM cells. This review article first describes the TGF-β superfamily of growth factors including BMPs and their canonical and noncanonical signaling pathways. The article then addresses the role of TGF-β2 in the pathophysiology of POAG as related to the ECM and ECM crosslinking enzymes. This is followed by a discussion of potential homeostatic control mechanisms of TGF-β2 signaling in the TM including the inhibitory role of BMP-4 and BMP-7. We then describe the relationship of TGF-β2 and BMPs in TM fibrosis including the role of antagonists. Lastly, in future directions, we identify potential future studies that explore new and unique cellular interactions within the TM for potential therapeutic interventions.

PMID: 24517218 [PubMed - as supplied by publisher]

Smad3 is necessary for transforming growth factor-beta2 induced ocular hypertension in mice.

Thu, 02/13/2014 - 5:42am
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Smad3 is necessary for transforming growth factor-beta2 induced ocular hypertension in mice.

Exp Eye Res. 2013 Nov;116:419-23

Authors: McDowell CM, Tebow HE, Wordinger RJ, Clark AF

Abstract
TGFβ2 induces extracellular matrix (ECM) remodeling and alters the cytoskeleton by both the canonical Smad and non-canonical signaling pathways. TGFβ2 regulates the expression of ECM proteins in trabecular meshwork (TM) cells, increases intraocular pressure (IOP) in an ex vivo perfusion organ culture model, and induces ocular hypertension in rodent eyes. A necessary step in the canonical Smad signaling pathway is phosphorylation of receptor protein Smad3 by the TGF-β receptor complex. The purpose of this study was to determine whether TGFβ2 signals in vivo through the canonical Smad signaling pathway in the TM using Smad3 knockout (KO) mice. Ad5.hTGFβ2(226/228) (2.5 × 10(7) pfu) was injected intravitreally into one eye of homozygous (WT), heterozygous (HET), and homozygous (KO) 129-Smad3(tm1Par)/J mice (n = 9-10 mice/group), with the uninjected contralateral eye serving as the control. IOP measurements were taken using a rebound tonometer. To test the effect of TGFβ2 signaling on the ECM, fibronectin expression was determined by immunohistochemistry and qPCR analysis. Transduction of the TM with viral vector Ad5.hTGFβ2(226/228) caused a statistically significant difference in IOP exposure between Smad3 genotypes: WT, 187.7 ± 23.9 mmHg*day (n = 9); HET, 95.6 ± 24.5 mmHg*day (n = 9); KO, 52.8 ± 25.2 mmHg*day (n = 10); (p < 0.05 WT versus HET, p < 0.01 WT versus KO). Immunohistochemistry and qPCR analysis showed that Ad5.hTGFβ2(226/228) increased fibronectin expression in the TM of WT mice (2.23 ± 0.24 fold) compared to Smad3 KO mice (0.99 ± 0.19 fold), p < 0.05. These results demonstrate Smad3 is a necessary signaling protein for TGFβ2-induced ocular hypertension and fibronectin deposition in the TM.

PMID: 24184030 [PubMed - indexed for MEDLINE]

Role of the Alternatively Spliced Glucocorticoid Receptor Isoform GRβ in Steroid Responsiveness and Glaucoma.

Wed, 02/12/2014 - 5:07am

Role of the Alternatively Spliced Glucocorticoid Receptor Isoform GRβ in Steroid Responsiveness and Glaucoma.

J Ocul Pharmacol Ther. 2014 Feb 7;

Authors: Jain A, Wordinger RJ, Yorio T, Clark AF

Abstract
Abstract Glucocorticoid (GC)-induced ocular hypertension (OHT) is a serious side effect of GC therapy in susceptible individuals. This OHT is due to increased aqueous humor (AH) outflow resistance in the trabecular meshwork (TM) caused by GC-mediated changes in TM structure and function. GCs may also play a role in the development of primary open-angle glaucoma (POAG). Elevated cortisol levels in the AH or enhanced GC sensitivity may be one of the reasons for elevated intraocular pressure in POAG patients. The GC OHT responder population is at greater risk of developing POAG compared with non-responders. We recently have gained insight into the molecular mechanisms responsible for this differential GC responsiveness, which is attributed to differences in GC receptor isoform expression in the TM. This article summarizes current knowledge on alternative GC receptor splicing to generate GC receptor alpha (GRα) and GRβ and their roles in the regulation of GC responsiveness in normal and glaucoma TM.

PMID: 24506296 [PubMed - as supplied by publisher]

Lineage(-)CD34(+)CD31(+) Cells That Appear in Association with Severe Burn Injury Are Inhibitory on the Production of Antimicrobial Peptides by Epidermal Keratinocytes.

Tue, 02/11/2014 - 4:24am

Lineage(-)CD34(+)CD31(+) Cells That Appear in Association with Severe Burn Injury Are Inhibitory on the Production of Antimicrobial Peptides by Epidermal Keratinocytes.

PLoS One. 2014;9(2):e82926

Authors: Yoshida S, Lee JO, Nakamura K, Suzuki S, Hendon DN, Kobayashi M, Suzuki F

Abstract
Antimicrobial peptides are major host defense effectors against Pseudomonas aeruginosa skin infections. Due to the lack of such peptide production, severely burned hosts are greatly susceptible to P. aeruginosa burn wound infection. β-Defensin (HBD) production by normal human epidermal keratinocytes (NHEK) was inhibited by lineage(-)CD34(+) cells isolated from peripheral blood of severely burned patients. Lineage(-)CD34(+) cells obtained from severely burned patients were characterized as CD31(+), while healthy donor lineage(-)CD34(+) cells were shown to be CD31(-) cells. Lineage(-)CD34(+)CD31(-) cells did not show any inhibitory activities on HBD-1 production by NHEK. CCL2 and IL-10 released from lineage(-)CD34(+)CD31(+) cells were shown to be inhibitory on the peptide production by NHEK, while these soluble factors were not produced by lineage(-)CD34(+)CD31(-) cells. After treatment with a mixture of mAbs for CCL2 and IL-10, the culture fluids of lineage(-)CD34(+)CD31(+) cells did not show any inhibitory activities on HBD-1 production by NHEK. Lineage(-)CD34(+)CD31(+) cells that appear in association with burn injuries play a role on the inhibition of antimicrobial peptide production by skin keratinocytes through the production of CCL2 and IL-10.

PMID: 24498256 [PubMed - in process]

Effect of glycyrrhizin on pseudomonal skin infections in human-mouse chimeras.

Tue, 02/11/2014 - 4:24am

Effect of glycyrrhizin on pseudomonal skin infections in human-mouse chimeras.

PLoS One. 2014 Jan 3;9(1):e83747

Authors: Yoshida S, Lee JO, Nakamura K, Suzuki S, Hendon DN, Kobayashi M, Suzuki F

Abstract
In our previous studies, peripheral blood lineage(-)CD34(+)CD31(+) cells (CD31(+) IMC) appearing in severely burned patients have been characterized as inhibitor cells for the production of β-defensins (HBDs) by human epidermal keratinocytes (NHEK). In this study, the effect of glycyrrhizin on pseudomonal skin infections was studied in a chimera model of thermal injury. Two different chimera models were utilized. Patient chimeras were created in murine antimicrobial peptide-depleted NOD-SCID IL-2rγ(null) mice that were grafted with unburned skin tissues of severely burned patients and inoculated with the same patient peripheral blood CD31(+) IMC. Patient chimera substitutes were created in the same mice that were grafted with NHEK and inoculated with experimentally induced CD31(+) IMC. In the results, both groups of chimeras treated with glycyrrhizin resisted a 20 LD50 dose of P. aeruginosa skin infection, while all chimeras in both groups treated with saline died within 3 days of the infection. Human antimicrobial peptides were detected from the grafted site tissues of both groups of chimeras treated with glycyrrhizin, while the peptides were not detected in the same area tissues of controls. HBD-1 was produced by keratinocytes in transwell-cultures performed with CD31(+) IMC and glycyrrhizin. Also, inhibitors (IL-10 and CCL2) of HBD-1 production by keratinocytes were not detected in cultures of patient CD31(+) IMC treated with glycyrrhizin. These results indicate that sepsis stemming from pseudomonal grafted site infections in a chimera model of burn injury is controllable by glycyrrhizin. Impaired antimicrobial peptide production at the infection site of severely burned patients may be restored after treatment with glycyrrhizin.

PMID: 24497916 [PubMed - in process]

Oxidative Stress, Testosterone, and Cognition among Caucasian and Mexican-American Men with and without Alzheimer's Disease.

Tue, 02/11/2014 - 4:24am

Oxidative Stress, Testosterone, and Cognition among Caucasian and Mexican-American Men with and without Alzheimer's Disease.

J Alzheimers Dis. 2014 Feb 4;

Authors: Cunningham RL, Singh M, O'Bryant SE, Hall JR, Barber RC

Abstract
Background: The use of testosterone among aging men has been increasing, but results from studies addressing the effectiveness of testosterone replacement therapy have been equivocal. Objective: Given our prior pre-clinical studies that reported a major influence of oxidative stress on testosterone's neuroprotective effects, we investigated whether the negative effects of testosterone on brain function were predicted by oxidative load. Methods: In order to test our hypothesis, we determined whether circulating total testosterone and luteinizing hormone correlated with cognition in a subset of the Texas Alzheimer's Research & Care Consortium (TARCC) cohort, consisting of Caucasian (n = 116) and Mexican-American (n = 117) men. We also assessed whether oxidative stress (as indexed by homocysteine levels) modified this relationship between sex hormones and cognition, and whether the levels of two antioxidants, superoxide dismutase-1 and glutathione S-transferase (GST), varied as a function of circulating testosterone. Results: In a low oxidative stress environment, testosterone was positively associated with the level of the antioxidant, GST, while no deleterious effects on cognitive function were noted. In contrast, under conditions of high oxidative stress (homocysteine levels >12 μM), testosterone and luteinizing hormone were associated with cognitive impairment, but only among Caucasians. The ethnic difference was attributed to significantly higher GST levels among Mexican-Americans. Conclusion: While testosterone may be beneficial under conditions of low oxidative stress, testosterone appears to have negative consequences under conditions of elevated oxidative stress, but only in Caucasians. Mexican-Americans, however, were protected from any deleterious effects of testosterone, potentially due to higher levels of endogenous antioxidant defenses such as GST.

PMID: 24496073 [PubMed - as supplied by publisher]

Preliminary assessment of microbiome changes following blood-feeding and survivorship in the Amblyomma americanum nymph-to-adult transition using semiconductor sequencing.

Thu, 02/06/2014 - 4:20am
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Preliminary assessment of microbiome changes following blood-feeding and survivorship in the Amblyomma americanum nymph-to-adult transition using semiconductor sequencing.

PLoS One. 2013;8(6):e67129

Authors: Menchaca AC, Visi DK, Strey OF, Teel PD, Kalinowski K, Allen MS, Williamson PC

Abstract
The physiology of ticks supports a diverse community of non-pathogenic and pathogenic organisms. This study aims to initially characterize the microbial community present within colony-reared Amblyomma americanum using PCR of the variable region 5 of the 16S rRNA gene followed by semiconductor sequencing and classification of sequence data using the Ribosomal Database Project and MG-RAST analysis tools. Comparison of amplicon library datasets revealed changes in the microbiomes in newly engorged nymphs, newly-molted adults, and aged adults, as well as ticks exposed to different environmental conditions. These preliminary data support the concept that microbe survivorship and diversity are partially dependent upon environmental variables and the sequence of blood feeding, molting, and aging. The maintenance and/or emergence of pathogens in ticks may be dependent in part on temporal changes in the microbial community of the tick microbiome.

PMID: 23826210 [PubMed - indexed for MEDLINE]