Abstract P3084: T Helper Cell Polarity Determines Salt-sensitivity And Development Of Hypertension

Abstract

Background: Sodium chloride drives the stable induction of pathogenic T helper (Th) 17 cells and development of hypertension. However, high-salt intake induces hypertension in salt-sensitive persons but not in salt-resistant persons. Pathogenic Th17 cell plays an important role in the development of hypertension whereas suppressive Treg cell plays an important role in the prevention of hypertension. Objective: We tested the hypothesis that . Methods and Results: Eight-week-old male SS and SR rats were fed chow (NS, 0.4% NaCl) or high-salt (HS, 4% NaCl) diet for 4 weeks. Systolic blood pressure was measured by the tail-cuff method. Cultured splenic T cells from Dahl salt-sensitive (SS) and salt-resistant (SR) rats were exposed to hypertonic salt solution with or without IL-6 or TGFβ. T helper cell (Th17 and Treg) polarity was determined via flow cytometry. The expression of Th17-related genes such as interleukin (IL)-17A, IL-23R and retinoic acid receptor-related orphan receptor (ROR) γt) as well as Treg-related genes such as IL-10, CD25 and forkhead box (Fox) P3 were measured by ELISA or qRT-PCR. Adoptive transfer of Th17 cells isolated from SS or SR donors fed HS were performed intraperitoneally into SS and SR recipients. Upon chow diet, SR has higher Treg cells than SS does. HS intake induced hypertension and increased proinflammatory Th17 cells in SS but not in SR. Hypertonic salt solution induced differentiation of cultured splenic T cells preferentially into proinflammatory Th17 cells and anti-inflammatory Treg cells in SS and SR, respectively. Polarizing cytokine IL-6 also induced differentiation of cultured splenic T cells preferentially into proinflammatory Th17 cells and anti-inflammatory Treg cells in SS and SR, respectively, which were further potentiated by hypertonic salt solution. Adoptive transfer of activated Th17 cells isolated from hypertensive SS or normotensive SR, both of which had been fed HS diet, induced hypertension in SS recipients, but not SR recipients. Conclusions: These results indicate that T helper cell polarity after HS intake determines salt-sensitivity and development of hypertension in SS and SR rats. Th17 cell polarity predicts salt-sensitivity and development of hypertension, whereas Treg cell polarity predicts salt-resistance and maintenance of normotension. SR rats protect against hypertension after HS intake through anti-inflammatory Treg cell polarity.