Home Blog of Signal Transduction Immunology & Inflammation TLR Chronic Inhibition of Toll-Like Receptor 9 Ameliorates Pulmonary Hypertension in Rats

Category

Archives

Popular Post

ESKM, a novel therapeutic agent for sensitive and resistant PH+ leukemias

The mechanism of resistance to JAK2 inhibitor in myeloproliferative neoplasms patients

Effects of PARP inhibitors in BRCA gene-mutated ovarian cancer

DASATINIB; An inhibitor of Receptor Tyrosine Kinase

GP130/JAK/STAT3 signaling pathway induces multiple myeloma

Chronic Inhibition of Toll-Like Receptor 9 Ameliorates Pulmonary Hypertension in Rats

Background Recent accumulating evidence suggests that toll-like receptor 9 (TLR9) is involved in the pathogenesis of cardiovascular diseases. However, its role in pulmonary hypertension remains uncertain. We hypothesized that TLR9 is involved in the development of pulmonary hypertension. Methods and Results A rat model of monocrotaline-induced pulmonary hypertension was used to investigate the effects of TLR9 on hemodynamic parameters, vascular remodeling, and survival. Monocrotaline-exposed rats significantly showed increases in plasma levels of mitochondrial DNA markers, which are recognized by TLR9, TLR9 activation in the lung, and interleukin-6 mRNA level in the lung on day 14 after monocrotaline injection. Meanwhile, monocrotaline-exposed rats showed elevated right ventricular systolic pressure, total pulmonary vascular resistance index and vascular remodeling, together with macrophage accumulation on day 21. In the preventive protocol, administration (days -3 to 21 after monocrotaline injection) of selective (E6446) or nonselective TLR9 inhibitor (chloroquine) significantly ameliorated the elevations of right ventricular systolic pressure and total pulmonary vascular resistance index as well as vascular remodeling and macrophage accumulation on day 21. These inhibitors also significantly reduced NF-κB activation and interleukin-6 mRNA levels to a similar extent. In the short-term reversal protocol, E646 treatment (days 14-17 after monocrotaline injection) almost normalized NF-κB activation and interleukin-6 mRNA level, and reduced macrophage accumulation. In the prolonged reversal protocol, E6446 treatment (days 14-24 after monocrotaline injection) reversed total pulmonary vascular resistance index and vascular remodeling, and improved survival in monocrotaline-exposed rats. Conclusions TLR9 is involved in the development of pulmonary hypertension concomitant via activation of the NF-κB‒IL-6 pathway. Inhibition of TLR9 may be a novel therapeutic strategy for pulmonary hypertension.

 

Comments：

The study investigated the role of toll-like receptor 9 (TLR9) in the development of pulmonary hypertension using a rat model of monocrotaline-induced pulmonary hypertension. The findings suggest that TLR9 is involved in the development of pulmonary hypertension via activation of the NF-κB‒IL-6 pathway. The study also found that administration of selective or nonselective TLR9 inhibitors significantly ameliorated the elevations of right ventricular systolic pressure and total pulmonary vascular resistance index as well as vascular remodeling and macrophage accumulation. The study concludes that inhibition of TLR9 may be a novel therapeutic strategy for pulmonary hypertension.

Related Products

Cat.No. Product Name Information
S6719 E6446 dihydrochloride E6446 dihydrochloride is a specific Toll-like receptor 9 inhibitor.

Related Targets

TLR