Department of Neuroscience, School of Medicine and Rockefeller Neuroscience Institute, West Virginia University, Morgantown, WV

Introduction/Background. Alkaline phosphatases (APs) are a family of ectoenzymes expressed in nearly all cell types. While these enzymes are presumed to possess primarily anti-inflammatory activity, a complete understanding of the underlying mechanisms responsible for AP activity in cells is less clear. For reasons that are not well understood, the enzymatic activity of the tissue-nonspecific alkaline phosphatase (TNAP) isoenzyme is more abundant in brain endothelial cells compared to endothelial cells in other organs. The molecular and cellular mechanisms underlying this difference are incompletely understood. We have previously demonstrated that pharmacological inhibition as well as genetic deletion of endothelial cell TNAP (EC-TNAP) disrupts the integrity of the blood-brain barrier.

Hypothesis/Goal of Study. In this seminar, data will be presented to support the hypothesis that brain EC-TNAP preserves the vascular integrity of the penumbra in ischemic stroke. Ischemic strokes comprise 85% of all strokes, and stroke represents the fifth leading cause of death and leading cause of disability in the United. States.

Methods and Results. Our studies compared experimental stroke outcomes between young and aged mice with an endothelial cell deletion of Alpl, the gene that encodes TNAP (AlplECKO mice), and their age- and sex-matched littermate controls (Alplfl/fl mice). The results presented will demonstrate a protective role for brain EC-TNAP in the ischemic penumbra as well as a reparative role for circulating extracellular vesicles generated from mice with a functional EC-TNAP.

Discussion/Conclusions. Taken together, these results demonstrate novel functional roles and therapeutic properties of TNAP in cerebrovascular disease.

Grant/Funding Support. P20 GM109098 and R01 AG068155

Abstract Embargoed

Aja Ceesay, Jayla-Danielle Sandifer, Luciano D. Mendoza, Clinton T. Case, and Erin B. Taylor
Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS

Introduction/Background. Systemic lupus erythematosus (SLE) is a multisystem autoimmune disorder that is primarily diagnosed in women and is characterized by prevalent autoantibody production. Treatments have improved life expectancy and quality of life for SLE patients, but chronic conditions such as hypertension, chronic kidney disease, and premature cardiovascular disease continue to plague this patient population. Recent studies have recognized that alterations in the gut microbiota, or gut dysbiosis, are associated with many autoimmune diseases, including SLE.

Hypothesis/Goal of Study. In the present study, we hypothesized that gut dysbiosis may play a role in SLE disease pathogenesis in the NZBWF1 mouse model of SLE, and that fecal microbiota transplantation (FMT) with gut microbes from control mice may improve these parameters.

Methods and Results. To test this hypothesis, control (NZW, n=20) and SLE (NZBWF1, n=20) mice were treated with broad spectrum antibiotics in drinking water for one week to deplete the existing microbiota. Subsequently, mice were given 0.1 mL of fecal microbes via oral gavage two times per week for four weeks in the following groups: Control-vehicle, Control-SLE microbes, SLE-vehicle, SLE-Control microbes. At the conclusion of the study, mice were implanted with carotid artery catheters to assess blood pressure. Mean arterial pressure was higher in SLE mice compared to control (Control: 112±3 vs. SLE: 140 ±2 mmHg, p<0.0001), and SLE mice that received FMT with control microbes had lower blood pressure (SLE-Control microbes: 126±4 mmHg, p=0.03). Circulating anti-dsDNA IgG autoantibody levels were elevated in SLE mice compared to control (Control: 149±38 vs. SLE: 527±114 kU/mL, p=0.02), and were significantly lower in SLE mice treated with control microbes (SLE-Control microbes: 229±70 kU/mL, p=0.03).

Discussion/Conclusions. These data suggest that gut microbiota present in NZBWF1 mice contribute to autoantibody production and the development of hypertension, and that interventions to alter the microbiota could have a beneficial impact on disease activity in
SLE patients.

Grant/Funding Support. NIH NIGMS P20GM104357, NIH NIGMS P30GM149404, and NIH NHLBI R00HL146888 to EBT