Life Sciences Commons^™

Selective Suppression Of The Α Isoform Of P38 Mapk Rescues Late-Stage Tau Pathology, Nicole Maphis, Shanya Jiang, Guixiang Xu, Olga N. Kokiko-Cochran, Saktimayee M. Roy, Linda J. Van Eldik, D. Martin Watterson, Bruce T. Lamb, Kiran Bhaskar

Sanders-Brown Center on Aging Faculty Publications

Background: Hyperphosphorylation and aggregation of tau protein are the pathological hallmarks of Alzheimer’s disease and related tauopathies. We previously demonstrated that the microglial activation induces tau hyperphosphorylation and cognitive impairment via activation of p38 mitogen-activated protein kinase (p38 MAPK) in the hTau mouse model of tauopathy that was deficient for microglial fractalkine receptor CX3CR1.

Method: We report an isoform-selective, brain-permeable, and orally bioavailable small molecule inhibitor of p38α MAPK (MW181) and its effects on tau phosphorylation in vitro and in hTau mice.

Results: First, pretreatment of mouse primary cortical neurons with MW181 completely blocked inflammation-induced p38α MAPK activation and AT8 …

Nicotinamide Adenine Dinucleotide Phosphate Oxidase 2 Regulates Lps-Induced Inflammation And Alveolar Remodeling In The Developing Lung., Heather Menden, Sheng Xia, Sherry M. Mabry, Angels Navarro, Michael F. Nyp, Venkatesh Sampath

Manuscripts, Articles, Book Chapters and Other Papers

In premature infants, sepsis is associated with alveolar simplification manifesting as bronchopulmonary dysplasia. The redox-dependent mechanisms underlying sepsis-induced inflammation and alveolar remodeling in the immature lung remain unclear. We developed a neonatal mouse model of sepsis-induced lung injury to investigate whether nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2) regulates Toll-like receptor (TLR)-mediated inflammation and alveolar remodeling. Six-day-old NOX2

Pleckstrin Homology (Ph) Domain Leucine-Rich Repeat Protein Phosphatase Controls Cell Polarity By Negatively Regulating The Activity Of Atypical Protein Kinase C, Xiaopeng Xiong, Xin Li, Yang-An Wen, Tianyan Gao

Markey Cancer Center Faculty Publications

The proper establishment of epithelial polarity allows cells to sense and respond to signals that arise from the microenvironment in a spatiotemporally controlled manner. Atypical PKCs (aPKCs) are implicated as key regulators of epithelial polarity. However, the molecular mechanism underlying the negative regulation of aPKCs remains largely unknown. In this study, we demonstrated that PH domain leucine-rich repeat protein phosphatase (PHLPP), a novel family of Ser/Thr protein phosphatases, plays an important role in regulating epithelial polarity by controlling the phosphorylation of both aPKC isoforms. Altered expression of PHLPP1 or PHLPP2 disrupted polarization of Caco2 cells grown in 3D cell cultures …

Reduced Efficacy Of Anti-AΒ Immunotherapy In A Mouse Model Of Amyloid Deposition And Vascular Cognitive Impairment Comorbidity, Erica M. Weekman, Tiffany L. Sudduth, Carly N. Caverly, Timothy J. Kopper, Oliver W. Phillips, David K. Powell, Donna M. Wilcock

Sanders-Brown Center on Aging Faculty Publications

Vascular cognitive impairment and dementia (VCID) is the second most common form of dementia behind Alzheimer's disease (AD). It is estimated that 40% of AD patients also have some form of VCID. One promising therapeutic for AD is anti-Aβ immunotherapy, which uses antibodies against Aβ to clear it from the brain. While successful in clearing Aβ and improving cognition in mice, anti-Aβ immunotherapy failed to reach primary cognitive outcomes in several different clinical trials. We hypothesized that one potential reason the anti-Aβ immunotherapy clinical trials were unsuccessful was due to this high percentage of VCID …

Repeated Closed Head Injury In Mice Results In Sustained Motor And Memory Deficits And Chronic Cellular Changes, Amanda Nicholle Bolton Hall, Binoy Joseph, Jennifer M. Brelsfoard, Kathryn E. Saatman

Spinal Cord and Brain Injury Research Center Faculty Publications

Millions of mild traumatic brain injuries (TBIs) occur every year in the United States, with many people subject to multiple head injuries that can lead to chronic behavioral dysfunction. We previously reported that mild TBI induced using closed head injuries (CHI) repeated at 24h intervals produced more acute neuron death and glial reactivity than a single CHI, and increasing the length of time between injuries to 48h reduced the cumulative acute effects of repeated CHI. To determine whether repeated CHI is associated with behavioral dysfunction or persistent cellular damage, mice receiving either five CHI at 24h intervals, five CHI at …

Ubr3, A Novel Modulator Of Hh Signaling Affects The Degradation Of Costal-2 And Kif7 Through Poly-Ubiquitination, Tongchao Li, Junkai Fan, Bernardo Blanco-Sánchez, Nikolaos Giagtzoglou, Guang Lin, Shinya Yamamoto, Manish Jaiswal, Kuchuan Chen, Jie Zhang, Wei Wei, Michael T. Lewis, Andrew K. Groves, Monte Westerfield, Jianhang Jia, Hugo J. Bellen

Markey Cancer Center Faculty Publications

Hedgehog (Hh) signaling regulates multiple aspects of metazoan development and tissue homeostasis, and is constitutively active in numerous cancers. We identified Ubr3, an E3 ubiquitin ligase, as a novel, positive regulator of Hh signaling in Drosophila and vertebrates. Hh signaling regulates the Ubr3-mediated poly-ubiquitination and degradation of Cos2, a central component of Hh signaling. In developing Drosophila eye discs, loss of ubr3 leads to a delayed differentiation of photoreceptors and a reduction in Hh signaling. In zebrafish, loss of Ubr3 causes a decrease in Shh signaling in the developing eyes, somites, and sensory neurons. However, not all tissues that require …

Mw151 Inhibited Il-1Β Levels After Traumatic Brain Injury With No Effect On Microglia Physiological Responses, Adam D. Bachstetter, Zhengqiu Zhou, Rachel K. Rowe, Bin Xing, Danielle S. Goulding, Alyssa N. Conley, Pradoldej Sompol, Shelby Meier, Jose F. Abisambra, Jonathan Lifshitz, D. Martin Watterson, Linda J. Van Eldik

Sanders-Brown Center on Aging Faculty Publications

A prevailing neuroinflammation hypothesis is that increased production of proinflammatory cytokines contributes to progressive neuropathology, secondary to the primary damage caused by a traumatic brain injury (TBI). In support of the hypothesis, post-injury interventions that inhibit the proinflammatory cytokine surge can attenuate the progressive pathology. However, other post-injury neuroinflammatory responses are key to endogenous recovery responses. Therefore, it is critical that pharmacological attenuation of detrimental or dysregulated neuroinflammatory processes avoid pan-suppression of inflammation. MW151 is a CNS-penetrant, small molecule experimental therapeutic that restores injury- or disease-induced overproduction of proinflammatory cytokines towards homeostasis without immunosuppression. Post-injury administration of MW151 in a …

Pi(4)P Promotes Phosphorylation And Conformational Change Of Smoothened Through Interaction With Its C-Terminal Tail, Kai Jiang, Yajuan Liu, Junkai Fan, Jie Zhang, Xiang-An Li, B. Mark Evers, Haining Zhu, Jianhang Jia

Markey Cancer Center Faculty Publications

In Hedgehog (Hh) signaling, binding of Hh to the Patched-Interference Hh (Ptc-Ihog) receptor complex relieves Ptc inhibition on Smoothened (Smo). A longstanding question is how Ptc inhibits Smo and how such inhibition is relieved by Hh stimulation. In this study, we found that Hh elevates production of phosphatidylinositol 4-phosphate (PI(4)P). Increased levels of PI(4)P promote, whereas decreased levels of PI(4)P inhibit, Hh signaling activity. We further found that PI(4)P directly binds Smo through an arginine motif, which then triggers Smo phosphorylation and activation. Moreover, we identified the pleckstrin homology (PH) domain of G protein-coupled receptor kinase 2 (Gprk2) as an …

Gap Junction Mediated Mirna Intercellular Transfer And Gene Regulation: A Novel Mechanism For Intercellular Genetic Communication, Liang Zong, Yan Zhu, Ruqiang Liang, Hong-Bo Zhao

Otolaryngology--Head & Neck Surgery Faculty Publications

Intercellular genetic communication is an essential requirement for coordination of cell proliferation and differentiation and has an important role in many cellular processes. Gap junction channels possess large pore allowing passage of ions and small molecules between cells. MicroRNAs (miRNAs) are small regulatory RNAs that can regulate gene expression broadly. Here, we report that miRNAs can pass through gap junction channels in a connexin-dependent manner. Connexin43 (Cx43) had higher permeability, whereas Cx30 showed little permeability to miRNAs. In the tested connexin cell lines, the permeability to miRNAs demonstrated: Cx43 > Cx26/30 > Cx26 > Cx31 > Cx30 = Cx-null. However, consistent with a uniform …

Serum Amyloid A Impairs The Antiinflammatory Properties Of Hdl, Chang Yeop Han, Chongren Tang, Myriam E. Guevara, Hao Wei, Tomasz Wietecha, Baohai Shao, Savitha Subramanian, Mohamed Omer, Shari Wang, Kevin D. O'Brien, Santica M. Marcovina, Thomas N. Wight, Tomas Vaisar, Maria C. De Beer, Frederick C. De Beer, William R. Osborne, Keith B. Elkon, Alan Chait

Physiology Faculty Publications

HDL from healthy humans and lean mice inhibits palmitate-induced adipocyte inflammation; however, the effect of the inflammatory state on the functional properties of HDL on adipocytes is unknown. Here, we found that HDL from mice injected with AgNO₃ fails to inhibit palmitate-induced inflammation and reduces cholesterol efflux from 3T3-L1 adipocytes. Moreover, HDL isolated from obese mice with moderate inflammation and humans with systemic lupus erythematosus had similar effects. Since serum amyloid A (SAA) concentrations in HDL increase with inflammation, we investigated whether elevated SAA is a causal factor in HDL dysfunction. HDL from AgNO₃-injected mice lacking Saa1.1 …