American Journal of Hypertension最新文献

Backround: Complement activation may facilitate hypertension through its effects on immune responses. The anaphylatoxin C5a, a major inflammatory effector, binds to the C5a receptors 1 and 2 (C5aR1, C5aR2). We have recently shown that C5aR1-/- mice have reduced hypertensive renal injury. The role of C5aR2 in hypertension is unknown.

Methods: For examination of C5aR2 expression on infiltrating and resident renal cells a tandem dye Tomato-C5aR2 knock-in reporter mouse was used. Human C5aR2 expression was analyzed in a single-cell RNAseq data set from the kidneys of hypertensive patients. Finally, we examined the effect of angiotensin II-induced hypertension in C5aR2-deficient mice.

Results: Flow cytometric analysis of leukocytes isolated from kidneys of the reporter mice showed that dendritic cells are the major C5aR2-expressing population (34%) followed by monocyte/macrophages (30%) and neutrophils (14%). Using confocal microscopy C5aR2 was not detected in resident renal or cardiac cells. In the human kidney, C5aR2 was also mainly found in monocytes, macrophages, and dendritic cells with a significantly higher expression in hypertension (P < 0.05). Unilateral nephrectomy was performed followed by infusion of Ang II (0.75 ng/g/min) and a high salt diet in wildtype (n = 18) and C5aR2-deficient mice (n = 14). Blood pressure, renal injury (albuminuria, glomerular filtration rate, glomerular and tubulointerstitial injury, inflammation), and cardiac injury (cardiac fibrosis, heart weight, gene expression) did not differ between hypertensive wildtype and C5aR2-/- mice.

Conclusions: In summary, C5aR2 is mainly expressed in myeloid cells in the kidney in mice and humans but its deficiency has no effect on Ang II-induced hypertensive injury.

Background: Previous studies with several limitations have comparatively analyzed the relationship between ambulatory blood pressure (BP) and self-measured BP and biomarkers of organ damage. This study extends this line of research by examining the relationship between ambulatory and self-measured BP and cardiac, renal, and atherosclerotic biomarkers in outpatients at cardiovascular risk.

Methods: In 1,440 practice outpatients who underwent office, ambulatory, and self-measured BP monitoring, we assessed the relationships of each BP with organ damage biomarkers including b-type natriuretic peptide (BNP), echocardiographic left ventricular mass index (LVMI), urine albumin-creatinine ratio (UACR), and brachial-ankle pulse wave velocity (baPWV).

Results: In the comparison of correlation, self-measured systolic BP (SBP) was more strongly correlated to log-transformed (Ln) BNP (n = 1,435; r = 0.123 vs. r = -0.093, P < 0.001), LVMI (n = 1,278; r = 0.223 vs. r = 0.094, P < 0.001), Ln-UACR (n = 1,435; r = 0.244 vs. r = 0.154, P = 0.010), and baPWV (n = 1,360; r = 0.327 vs. r = 0.115, P < 0.001) than daytime ambulatory SBP. In the linear regression models including office, ambulatory, and self-measured SBP, only self-measured SBP was significantly related to Ln-BNP (P = 0.016) and LVMI (P < 0.001). In the logistic regression models for the top quartile of LVMI, adding self-measured SBP improved the model predictability (P = 0.027), but adding daytime ambulatory SBP did not. However, adding daytime ambulatory SBP improved the model predictability in the logistic model for the top quartile of baPWV including office and self-measured SBP (P = 0.030).

Conclusions: Our study findings suggested that self-measured BP was associated with cardiac biomarkers independent of ambulatory BP.

Background: This study aims to explore the association between a healthy lifestyle and abnormal ambulatory blood pressure (ABP) in Chinese youths.

Methods: A school-based sample of 1,296 college students was investigated. A lifestyle score was calculated by synthesizing 5 lifestyle factors, including smoking, alcohol consumption, diet, physical activity, and sleeping. The total score ranged from 0 to 5, with a higher score indicating a healthier lifestyle. This score was then divided into 3 categories representing low adherence to a healthy lifestyle (0-2), medium adherence (3), and high adherence (4-5). Abnormal 24-hour blood pressure (BP) was defined as systolic BP (SBP) ≥ 130 mm Hg and/or diastolic BP (DBP) ≥ 80 mm Hg. Abnormal daytime BP was determined as daytime SBP ≥ 135 mm Hg and/or DBP ≥ 85 mm Hg, while abnormal nighttime BP was characterized as nighttime SBP ≥ 120 mm Hg and/or DBP ≥ 70 mm Hg. We assessed the associations using the binomial regression model.

Results: Mean age was 18.81 years, and 74.5% were women. The prevalence of abnormal 24-hour BP, daytime BP, and nighttime BP are 4.2%, 3.7%, and 9.0%, respectively. We found that participants with a high level of adherence to a healthy lifestyle had a significantly lower prevalence of abnormal 24-hour BP [prevalence ratios (PR) = 0.15, 95% CI: 0.05, 0.48] and abnormal daytime BP (PR = 0.16, 95%CI: 0.05, 0.52), when compared to those with a low level of adherence and after adjusting for the potential covariates.

Conclusions: A healthier lifestyle is associated with a better ambulatory BP profile among youths.

Background: In the hypothalamic paraventricular nucleus (PVN) of spontaneously hypertensive rats (SHRs), the expression of the testis-specific protein, Y-encoded-like 2 (TSPYL2) and the phosphorylation level of Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) are higher comparing with the normotensive Wistar Kyoto rats (WKY). But how they are involved in hypertension remains unclear. TSPYL2 may interact with JAK2/STAT3 in PVN to sustain high blood pressure during hypertension.

Methods: Knockdown of TSPYL2 via adeno-associated virus (AAV) carrying shRNA was conducted through bilateral microinjection into the PVN of SHR and WKY rats. JAK2/STAT3 inhibition was achieved by intraperitoneally or PVN injection of AG490 into the SHRs. Blood pressure (BP), plasma norepinephrine (NE), PVN inflammatory response, and PVN oxidative stress were measured.

Results: TSPYL2 knock-down in the PVN of SHRs but not WKYs led to reduced BP and plasma NE, deactivation of JAK2/STAT3, decreased expression of pro-inflammatory cytokine IL-1β, and increased expression of anti-inflammatory cytokine IL-10 in the PVN. Meanwhile, AG490 administrated in both ways reduced the BP in the SHRs and deactivated JAK2/STAT3 but failed to change the expression of TSPYL2 in PVN. AG490 also downregulated expression of IL-1β and upregulated expression of IL-10. Both knockdown of TSPYL2 and inhibition of JAK2/STAT3 can reduce the oxidative stress in the PVN of SHRs.

Conclusion: JAK2/STAT3 is regulated by TSPYL2 in the PVN of SHRs, and PVN TSPYL2/JAK2/STAT3 is essential for maintaining high BP in hypertensive rats, making it a potential therapeutic target for hypertension.