Correlation between Histone Deacetylase 9 and Regulatory T Cell in Patients with Chronic Heart Failure

Summary Heart failure (HF) is the end stage of various kinds of cardiovascular diseases and leads to a high mortality worldwide. Numerous studies have demonstrated that frequencies of CD4+CD25+Foxp3+ regulatory T cells (Tregs) are reduced in HF patients and properly expanding Tregs attenuates HF progression. Histone deacetylase (HDAC) 9 has been revealed to contribute to several cardiovascular and cerebrovascular diseases. Plenty of studies showed that HDAC9 negatively regulated the number and function of Tregs. Thus, we aim to investigate the expression of HDAC 9 in patients with chronic heart failure (CHF) and the relationship among HDAC9, Tregs and CHF. Our research showed a reduced number of Tregs and an increased expression of HDAC9 mRNA in CHF patients. Patients with CHF were divided into two groups by heart function grade of New York Heart Association (NYHA), we found that the HDAC9 mRNA expression level in NYHA grade II–III group were lower than that in NYHA grade IV group. More importantly, the correlation study suggested that the expression of HDAC9 mRNA was negatively correlated to Tregs frequency and left ventricular ejection fraction (LVEF), whereas positively correlated to larger left ventricular end-diastolic dimension (LVEDD) and B-type natriuretic peptide (BNP) in patients with CHF. The correlation studies also showed a positive correlation between HDAC9 and the severity of CHF. Our research suggests that HDAC9 may be a new indicator for assessing CHF and it may offer a new direction for research of CHF.