Abstract 123: Partial Endothelial Cell In Vivo Reprogramming Reverses The Hypercontractility To Phenylephrine In Resistance Arteries Isolated From Males But Not From Females BPH/2J Hypertensive Mice

Abstract

The Schlager hypertensive (BPH/2J) mouse strain is a genetic model of spontaneoushypertension. Endothelial dysfunction is a hallmark characteristic of hypertension,including endothelial phenotypic transition. We hypothesized that treating endothelialcells with the transcription factors Oct4, Sox2 and Klf4, will lead to partial reprogramming,reduce non-functional phenotype changes, and prevent vascular dysfunction. Mouseendothelial cells were transduced with a lentiviral vector containing VE-cadherin-Oct4-Sox2-Klf4-eGFP (LVTF), control lentivirus (LVCO), or phosphate buffer saline (PBS).After 72h, cell migration and proliferation, Ki67 marker, and the endothelial progenitormarkers (CD31, CD133 and CD34) were evaluated. Male or female BPH/2J mice (33-42-week-old) and their age-matched controls BPN/3J (normotensive) received a singleinjection of LVCO or LVTF (100μL) via the tail vein and were evaluated after 10 days.Systolic blood pressure (SBP) was measured directly by catheterization of the left carotidartery. Mesenteric resistance arteries were isolated and mounted on wire myographs toevaluate phenylephrine-induced contraction. Data were analyzed using One-way orTwo-way ANOVA, with Bonferroni correction ( p <0.05). Lentivirus-transduced endothelialcells had eGFP fluorescence (LVCO: 45±2%, LVTF:19±1%, n=5), and LVTF increasedOct4 (LVTF: 5.6±0.7% vs. LVCO: 1.8±0.2% vs. PBS: 1.5±0.4%, n=5) and CD133 (LVTF:11.7±0.8% vs. LVCO: 7.6±0.3% vs. PBS: 6.5±0.5%, n=5), but not CD31, CD34 or Ki67.Cell migration was lower in LVTF (71±2%) than LVCO cells (90±2%, n=5). Male andfemale BPH/2J treated with LVCO had higher SBP (male: 103±3mmHg, female:95±4mmHg, n=2-3) compared to BPN/3J mice (male: 88±1mmHg, female: 80±4mmHg,n=2-6), and LVTF treatment tended to decrease SBP in male BPH/2J (86±2mmHg, n=2, p =0.0548) but not in female mice (90±4mmHg, n=3). Phenylephrine-induced contractionwas reduced in arteries from male BPH/2J treated with LVTF (6.77±0.90mN, n=3), butnot in female mice (11.01±1.45mN, n=3) compared to LVCO (male: 12.23±0.15mN;female: 10.77±0.92mN; n=2-3). These data reveal that partial endothelial cellreprogramming in vivo is a new strategy to prevent endothelial dysfunction in malehypertensive mice.1