Fig 1.
Blood pressure is reduced in human and murine sickle cell disease.
(A) Systolic and diastolic blood pressures were determined in age-matched healthy control (HbAA, N = 35) individuals and patients with SCA (HbSS, N = 58). (B) Mean systolic arterial blood pressure (BP) was determined in SCD (SCD, N = 6–12) and control (CON, N = 10–14) chimeric mice at 5, 8 and 9 months of age, data are means of three measurements on three different days. **, P<0.01; ***, P<0.001, compared to HbAA or CON.
Fig 2.
Measurement of plasma ACE in SCD.
(A) Plasma ACE in patients with SCA (SS, N = 34) and healthy individuals (AA, N = 29). (B) Correlation between diastolic BP and ACE in SCA patients (N = 31). (C) Activity of ACE in the plasma of patients with SCA (SS, N = 12) and healthy individuals (AA, N = 6). (D) Plasma ACE in chimeric mice with SCD (SCD, N = 11) and control (CON, N = 9) mice at 5 months of age. (E) Correlation between mean systolic BP and ACE in SCD mice. Plasma ACE was measured by ELISA. *, P<0.05; **, P<0.01; ***, P<0.001 compared to AA or CON.
Fig 3.
Measurement of plasma Ang II and renin in SCD.
(A) Plasma Ang II in patients with SCA (SS, N = 58) and healthy individuals (AA, N = 40). (B) Correlation between diastolic BP and Ang II in SCA patients (N = 54). (C) Plasma Ang II in chimeric mice with SCD (SCD) and control (CON) mice at 5 and 9 months of age (N = 4–11). (D) Correlation between mean systolic BP and Ang II in SCD mice. (E) Plasma renin in chimeric mice with SCD (SCD) and control (CON) mice at 5 and 9 months of age (N = 3–6). (F) Correlation between mean systolic BP and renin in SCD mice. Plasma Ang II and renin were measured by ELISA. *, P<0.05; **, P<0.01, compared to CON.
Fig 4.
Expression and distribution of angiotensin and ACE in the kidneys of control (CON) and SCD (SCD) mice.
Immunofluorescent staining of kidney sections for angiotensin and ACE. Angiotensin (I, II and III) was stained with anti-angiotensin and AlexaFluor®488-conjugated secondary antibody (green); ACE was detected with anti-ACE and AlexaFluor®555-conjugated secondary antibody (red); nuclei were stained with DAPI (blue). The arrows show tubule (white) and glomerular (yellow) structures. Images are representative of three kidney sections from N = 3 mice. Scale bar = 50 μm and 20 μm (Magnified merge).
Fig 5.
Effects of ACE inhibition upon blood pressure, proteinuria and systemic RAS protein expression and production in SCD mice.
Control (CON) and SCD (SCD) mice (5 months old) were treated, or not, for 5 weeks with 25 mg/kg/day enalapril. (A) Plasma Ang II and (B) plasma renin were determined by ELISA at 72 h after the last dose of enalapril (CON, N = 7–11; SCD, N = 7–11); ACE activity in the kidney (C) and heart (D) of mice, as determined by fluorometric assay (CON, N = 3–6; SCD, N = 3–5). Gene expressions of Mcpt4 (encoding mast cell protease-4) in hearts (E) and Ace2 (encoding ACE-2) in lungs (F) of mice were determined by qPCR and are depicted as arbitrary units (A.U.) of expression (N = 2–5), relative to the expressions of Actb and Gpdh; Gene expressions of (G) Lcn2 (encoding NGAL), (H) Havcr1 (encoding KIM-1), and (I) Mmp9 (encoding MMP9) in the kidneys of mice were determined by qPCR and are depicted as arbitrary units (A.U.) of expression (N = 7–10), relative to the expressions of Actb and Gpdh; (J) Mean systolic arterial blood pressure (BP); data are means of three measurements on three different days; CON, N = 5–8; SCD, N = 5–8. Values depicted are means ± SEM. *,P<0.05; ***, P<0.001, compared to untreated CON mice.