Author(s): Coppo M, Bandinelli M, Berni A, Galastri S, Abbate R,
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Abstract BACKGROUND: Low-grade inflammation facilitates the development of essential hypertension and target organ damage (TOD). Recently, human T-lymphocytes were shown to be endowed with a functional active renin-angiotensin system (RAS). We investigated whether in hypertensive patients a selective angiotensin (Ang) II-driven upregulation of T-cell RAS occurs and whether it is differently modulated in presence of low-grade inflammation. METHODS: T-lymphocytes were obtained from 21 hypertensives (I-II World Health Organization class; 16 males, 5 females; 56 ± 11 years). Low-grade inflammation was defined for high sensitive C-reactive protein (hsCRP) > 2 mg/l. Ten healthy subjects formed the age- and sex-matched control group. After T-lymphocytes isolation, mRNAs for angiotensin-converting enzyme (ACE) and angiotensin type 1 receptor (AT1-R) were quantified by reverse-transcriptase PCR with or without 0.1 pmol/l Ang II in addition to T-cells cultures. Cell pellet and supernatant ACE activity and Ang II content were measured. Cardiac and renal TOD-indexes were evaluated. RESULTS: Both in controls and hypertensives, Ang II-stimulation significantly increased ACE and AT1-R mRNA levels (P < 0.05). In patients, the increase was earlier and higher than controls, with the highest values in hypertensives with > 2 mg/l hsCRP. Peak Ang II-induced ACE and AT1-R mRNA levels were positively related to hsCRP, systolic blood pressure and body mass index (BMI) at the univariate analyses. The stepwise regression analyses selected hsCRP (r = 0.47) and left ventricular mass index (LVMI) (r = 0.50) as the variables independently related to peak ace-gene expression, while BMI resulted independently related to peak AT1-R gene expression (P < 0.001). CONCLUSIONS: In hypertension, an Ang II-driven activation of T-cell RAS, further amplified by low-grade inflammation, does occur and is associated to worse TOD. New therapeutic approaches aimed at this specific target might be proposed to control hypertension and hypertensive damage.
This article was published in Am J Hypertens
and referenced in Journal of Clinical & Cellular Immunology