Zahner D.,Emory University |
Zahner D.,Research 151 |
Zhou X.,Emory University |
Zhou X.,Research 151 |
And 8 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2010
Macrolide resistance is a major concern in the treatment of Streptococcus pneumoniae. Inducible macrolide resistance in this pneumococcus is mediated by the efflux pump MefE/Mel. We show here that the human antimicrobial peptide LL-37 induces the mefE promoter and confers resistance to erythromycin and LL-37. Such induction may impact the efficacy of host defenses and of macrolide-based treatment of pneumococcal disease. Copyright © 2010, American Society for Microbiology. All Rights Reserved.
Cho H.,University of Tennessee Health Science Center |
Cho H.,Research 151 |
Zook J.,University of Memphis |
Banner T.,University of Memphis |
And 6 more authors.
Tissue Engineering and Regenerative Medicine | Year: 2014
Self-assembled gold monolayers offer several advantages for the realization of novel modified electrodes for biosensor applications. This is due to their ability to decrease non-specific adsorption and provide for covalent attachment of biomolecules. Surfaces for these applications require the precise control of ligand density, the ability to immobilize ligands, and in situ-modulation of ligand activity. In this study, we focused our studies on the immobilization of antibody on a gold monolayer surface. We self-assembled thioctic acid onto the gold surface as an anchor point for the immobilization of anti-fibrinogen onto the surface. The modifications to the gold surface were characterized by ELISA, ellipsometry, and AFM.
Duffy C.M.,Research 151 |
Duffy C.M.,University of Minnesota |
Nixon J.P.,Research 151 |
Nixon J.P.,University of Minnesota |
And 2 more authors.
Molecular and Cellular Neuroscience | Year: 2016
Palmitic acid (PA), an abundant dietary saturated fatty acid, contributes to obesity and hypothalamic dysregulation in part through increase in oxidative stress, insulin resistance, and neuroinflammation. Increased production of reactive oxygen species (ROS) as a result of PA exposure contributes to the onset of neuronal apoptosis. Additionally, high fat diets lead to changes in hypothalamic gene expression profiles including suppression of the anti-apoptotic protein B cell lymphoma 2 (Bcl-2) and upregulation of the pro-apoptotic protein B cell lymphoma 2 associated X protein (Bax). Orexin A (OXA), a hypothalamic peptide important in obesity resistance, also contributes to neuroprotection. Prior studies have demonstrated that OXA attenuates oxidative stress induced cell death. We hypothesized that OXA would be neuroprotective against PA induced cell death. To test this, we treated an immortalized hypothalamic cell line (designated mHypoA-1/2) with OXA and PA. We demonstrate that OXA attenuates PA-induced hypothalamic cell death via reduced caspase-3/7 apoptosis, stabilization of Bcl-2 gene expression, and reduced Bax/Bcl-2 gene expression ratio. We also found that OXA inhibits ROS production after PA exposure. Finally, we show that PA exposure in mHypoA-1/2 cells significantly reduces basal respiration, maximum respiration, ATP production, and reserve capacity. However, OXA treatment reverses PA-induced changes in intracellular metabolism, increasing basal respiration, maximum respiration, ATP production, and reserve capacity. Collectively, these results support that OXA protects against PA-induced hypothalamic dysregulation, and may represent one mechanism through which OXA can ameliorate effects of obesogenic diet on brain health. © 2016
Stein J.J.,SUNY Upstate Medical University |
Stein J.J.,Research 151 |
Iwuchukwu C.,SUNY Upstate Medical University |
Iwuchukwu C.,Research 151 |
And 4 more authors.
Molecular and Cellular Biochemistry | Year: 2013
Angioplasty causes local vascular injury, leading to the release of thrombospondin-1 (TSP-1), which stimulates vascular smooth muscle cell (VSMC) migration and proliferation, important steps in the development of intimal hyperplasia. Transforming growth factor beta 2 (TGF-β2) and hyaluronic acid synthase (HAS) are two pro-stenotic genes upregulated in VSMCs by TSP-1. We hypothesized that inhibition of TGF-β2 or HAS would inhibit TSP-1-induced VSMC migration, proliferation, and TSP-1 signaling. Our data demonstrate that Inhibition of either TGF-β2 or HAS inhibited TSP-1-induced VSMC migration and proliferation. Activation of ERK 1 was decreased by TGF-β2 inhibition and unaffected by HAS inhibition. TGF-β2 and HAS are not implicated in TSP-1-induced thbs1 expression, while they are each implicated in TSP-1-induced expression of their own gene. In summary, TSP-1-induced VSMC migration and proliferation rely on intact TGF-β2 signaling and HAS function. TSP-1 activation of ERK 1 is dependent on TGF-β2. These data further expand our understanding of the complexity of TSP-1 cellular signaling and the involvement of TGF-β2 and HAS. © 2013 Springer Science+Business Media New York (outside the USA).
Dang I.,Hines Veterans Administration Hospital |
Dang I.,Loyola University |
De Vries G.H.,Research 151 |
De Vries G.H.,Virginia Commonwealth University
Neurochemical Research | Year: 2011
Malignant peripheral nerve sheath (MPNST) cell lines derived from patients with neurofibromatosis type 1 (NF!) were found to have basal cAMP levels which are two-fold higher than cAMP levels in normal human adult Schwann cells (nHSC). PCR analysis also revealed that normal adult human Schwann cells express mRNA for types Ill, IV, and IX adenylyl cyclase (AC) while NF1 MPNST cells express AC mRNA of types II, V, and VIII in addition to expressing all the isoforms of normal adult human Schwann cells. Further PCR analysis revealed that NF1 MPNST lines express mRNA for EP2 and EP4 prostaglandin receptors whereas nHSC only express mRNA for the EP2 receptor. Exogenous prostaglandins alone or in combination with PDGF BB induced greater increases in cAMP levels and proliferation of NF1 MPNST cells compared to nHSC. We conclude that aberrant cAMP signaling in NF1 MPNST cells contributes to tumor formation in NF1 patients. © Springer Science+Business Media, LLC 2011.