A narrative review of prehypertension and the cardiovascular system: effects and potential pathogenic mechanisms

Puerarin Alleviates Blood Pressure via Inhibition of ROS/TLR4/NLRP3 Inflammasome Signaling Pathway in the Hypothalamic Paraventricular Nucleus of Salt-Induced Prehypertensive Rats

BACKGROUND

Puerarin is an isoflavone compound isolated from the roots of a leguminous plant, the wild kudzu. Various functional activities of this compound in multiple diseases have been reported. However, the effect and mechanism of puerarin in improving blood pressure remain non-elucidated.

PURPOSE

The current study was designed to assess the preventive effects of puerarin on the onset and progression of hypertension and to verify the hypothesis that puerarin alleviates blood pressure by inhibiting the ROS/TLR4/NLRP3 inflammasome signaling pathway in the hypothalamic paraventricular nucleus (PVN) of salt-induced prehypertensive rats.

METHODS

Male Dahl salt-sensitive rats were fed low NaCl salt (3% in drinking water) for the control (NS) group or 8% (HS) to induce prehypertension. Each batch was divided into two group and treated by bilateral PVN microinjection with either artificial cerebrospinal fluid or puerarin through a micro-osmotic pump for 6 weeks. The mean arterial pressure (MAP) was recorded, and samples were collected and analyzed.

RESULTS

We concluded that puerarin significantly prevented the elevation of blood pressure and effectively alleviated the increase in heart rate caused by high salt. Norepinephrine (NE) in the plasma of salt-induced prehypertensive rats also decreased upon puerarin chronic infusion. Additionally, analysis of the PVN sample revealed that puerarin pretreatment decreased the positive cells and gene level of TLR4 (Toll-like receptor 4), NLRP3, Caspase-1 p10, NOX2, MyD88, NOX4, and proinflammatory cytokines in the PVN. Puerarin pretreatment also decreased NF-κBp65 activity, inhibited oxidative stress, and alleviated inflammatory responses in the PVN.

CONCLUSION

We conclude that puerarin alleviated blood pressure via inhibition of the ROS/TLR4/NLRP3 inflammasome signaling pathway in the PVN, suggesting the therapeutic potential of puerarin in the prevention of hypertension.

Improved arterial stiffness after combined aerobic and resistance training: correlation with heart rate variability change in prehypertensive offspring of hypertensive parents

Prehypertensive offspring of hypertensive parents are strongly linked to pathological processes of hypertension in later life. It is observed that young adults with high blood pressure (BP) have increased arterial stiffness, which is linked to autonomic anomalies. The purpose of the present study was to assess the effect of combined resistance and aerobic exercise training on BP, brachial-ankle pulse wave velocity (baP-WV), and heart rate variability (HRV) in prehypertensive young men with hypertensive parents. Thirty prehypertensive males aged 19.6±1.2 years were randomly assigned to either a combined exercise training group (CBT, n=15) or no exercise group (CON, n=15). The CBT group performed combined exercise for 8 weeks, 3 times per week. BP, baP-WV, HRV, peak oxygen consumption (VO_2peak), and muscle strength were measured before and after the exercise intervention. Systolic BP (-5.1 mmHg, 3.9% decrease, P<0.05), diastolic BP (-3.9 mmHg, 6.1% decrease, P<0.01), mean arterial pressure (-4.2 mmHg, 4.7% decrease, P<0.05), baPWV (-0.4 m/sec, 3.5% decrease, P<0.01), standard deviation of all RR intervals (+58.5% increase, P<0.05) and very low frequency (VLF) (+34.6% increase, P<0.01), VO_2peak (+11.7% increase, P<0.01) and one-repetition maximum leg press (+30.3% increase, P<0.01) were significantly improved in the CBT group after 8 weeks of training versus the CON group. Additionally, a reduction in baPWV was associated with an increase in the VLF power of HRV (r=0.72, P<0.01). These findings indicate that the combined training improves BP, arterial stiffness, vagal activity, cardiorespiratory fitness, and lower-body muscle strength in prehypertensive offspring of hypertensive parents.

Fluid Shear Stress Ameliorates Prehypertension-Associated Decline in Endothelium-Reparative Potential of Early Endothelial Progenitor Cells

This study investigated the effects of prehypertension and shear stress on the reendothelialization potential of human early EPCs and explored its potential mechanisms. Early EPCs from the prehypertensive patients showed reduced migration and adhesion in vitro and demonstrated a significantly impaired in vivo reendothelialization capacity. Shear stress pretreatment markedly promoted the in vivo reendothelialization capacity of EPCs. Although basal CXCR4 expression in early EPCs from prehypertensive donors was similar to that from healthy control, SDF-1-induced phosphorylation of CXCR4 was lower in prehypertensive EPCs. Shear stress up-regulated CXCR4 expression and increased CXCR4 phosphorylation, and restored the SDF-1/CXCR4-dependent JAK-2 phosphorylation in prehypertensive EPCs. CXCR4 knockdown or JAK-2 inhibitor treatment prevents against shear stress-induced increase in the migration, adhesion and reendothelialization capacity of the prehypertensive EPCs. Collectively, CXCR4 receptor profoundly modulates the reendothelialization potential of early EPCs. The abnormal CXCR4-mediated JAK-2 signaling may contribute to impaired functions of EPCs from patients with prehypertension.