Medicine and Health 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 …

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 …

Integrated Molecular Pathway Analysis Informs A Synergistic Combination Therapy Targeting Pten/Pi3k And Egfr Pathways For Basal-Like Breast Cancer, Qing-Bai She, Sofia K. Gruvberger-Saal, Matthew Maurer, Yilun Chen, Mervi Jumppanen, Tao Su, Meaghan Dendy, Ying-Ka Ingar Lau, Lorenzo Memeo, Hugo M. Horlings, Marc J. Van De Vijver, Jorma Isola, Hanina Hibshoosh, Neal Rosen, Ramon Parsons, Lao H. Saal

Markey Cancer Center Faculty Publications

Background: The basal-like breast cancer (BLBC) subtype is characterized by positive staining for basal mammary epithelial cytokeratin markers, lack of hormone receptor and HER2 expression, and poor prognosis with currently no approved molecularly-targeted therapies. The oncogenic signaling pathways driving basal-like tumorigenesis are not fully elucidated.

Methods: One hundred sixteen unselected breast tumors were subjected to integrated analysis of phosphoinositide 3-kinase (PI3K) pathway related molecular aberrations by immunohistochemistry, mutation analysis, and gene expression profiling. Incidence and relationships between molecular biomarkers were characterized. Findings for select biomarkers were validated in an independent series. Synergistic cell killing in vitro and in vivo tumor …

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 …

Structure And Functions Of Angiotensinogen, Hong Lu, Lisa A. Cassis, Craig W. Vander Kooi, Alan Daugherty

Saha Cardiovascular Research Center Faculty Publications

Angiotensinogen (AGT) is the sole precursor of all angiotensin peptides. Although AGT is generally considered as a passive substrate of the renin–angiotensin system, there is accumulating evidence that the regulation and functions of AGT are intricate. Understanding the diversity of AGT properties has been enhanced by protein structural analysis and animal studies. In addition to whole-body genetic deletion, AGT can be regulated in vivo by cell-specific procedures, adeno-associated viral approaches and antisense oligonucleotides. Indeed, the availability of these multiple manipulations of AGT in vivo has provided new insights into the multifaceted roles of AGT. In this review, the combination of …

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 …

Calpain-5 Expression In The Retina Localizes To Photoreceptor Synapses, Kellie A. Schaefer, Marcus A. Toral, Gabriel Velez, Allison J. Cox, Sheila A. Baker, Nicholas C. Borcherding, Diana F. Colgan, Vimala Bondada, Charles B. Mashburn, Chen Guang Yu, James W. Geddes, Stephen H. Tsang, Alexander G. Bassuk, Vinit B. Mahajan

Spinal Cord and Brain Injury Research Center Faculty Publications

Purpose: We characterize calpain-5 (CAPN5) expression in retinal and neuronal subcellular compartments.

Methods: CAPN5 gene variants were classified using the exome variant server, and RNA-sequencing was used to compare expression of CAPN5 mRNA in the mouse and human retina and in retinoblastoma cells. Expression of CAPN5 protein was ascertained in humans and mice in silico, in mouse retina by immunohistochemistry, and in neuronal cancer cell lines and fractionated central nervous system tissue extracts by Western analysis with eight antibodies targeting different CAPN5 regions.

Results: Most CAPN5 genetic variation occurs outside its protease core; and searches …

Tgf-Β Neutralization Enhances Angii-Induced Aortic Rupture And Aneurysm In Both Thoracic And Abdominal Regions, Xiaofeng Chen, Debra L. Rateri, Deborah A. Howatt, Anju Balakrishnan, Jessica J. Moorleghen, Lisa A. Cassis, Alan Daugherty

Saha Cardiovascular Research Center Faculty Publications

AngII and TGF-β interact in development of thoracic and abdominal aortic diseases, although there are many facets of this interaction that have not been clearly defined. The aim of the present study was to determine the effects of TGF-β neutralization on AngII induced-aortic pathologies. Male C57BL/6J mice were administered with either a rabbit or mouse TGF-β neutralizing antibody and then infused with AngII. The rabbit TGF-β antibody modestly reduced serum TGF-β concentrations, with no significant enhancements to AngII-induced aneurysm or rupture. Administration of this rabbit TGF-β antibody in mice led to high serum titers against rabbit IgG that may have …

Correlation Of Maximal Inspiratory Pressure To Transdiaphragmatic Twitch Pressure In Intensive Care Unit Patients, Gerald S. Supinski, Philip M. Westgate, Leigh Ann Callahan

Internal Medicine Faculty Publications

Background: Respiratory muscle weakness contributes to respiratory failure in ICU patients. Unfortunately, assessment of weakness is difficult since the most objective test, transdiaphragmatic pressure in response to phrenic nerve stimulation (PdiTw), is difficult to perform. While most clinicians utilize maximum inspiratory pressure (Pimax) to assess strength, the relationship of this index to PdiTw has not been evaluated in a large ICU population. The purpose of the present study was to assess both PdiTw and Pimax in ICU patients to determine how these indices correlate with each other, what factors influence these indices, and how well these indices predict outcomes.

Methods: …

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 …

Sglt2 Inhibitor Therapy Improves Blood Glucose But Does Not Prevent Diabetic Bone Disease In Diabetic Dba/2j Male Mice, Kathryn M. Thrailkill, R. Clay Bunn, Jeffry S. Nyman, Mallikarjuna R. Rettiganti, Gael E. Cockrell, Elizabeth C. Wahl, Sasidhar Uppuganti, Charles K. Lumpkin, John L. Fowlkes

Barnstable Brown Diabetes Center Faculty Publications

Persons with type 1 and type 2 diabetes have increased fracture risk, attributed to deficits in the microarchitecture and strength of diabetic bone, thought to be mediated, in part, by the consequences of chronic hyperglycemia. Therefore, to examine the effects of a glucose-lowering SGLT2 inhibitor on blood glucose (BG) and bone homeostasis in a model of diabetic bone disease, male DBA/2J mice with or without streptozotocin (STZ)-induced hyperglycemia were fed chow containing the SGLT2 inhibitor, canagliflozin (CANA), or chow without drug, for 10 weeks of therapy. Thereafter, serum bone biomarkers were measured, fracture resistance of cortical bone was assessed by …