Inhibiting IL-6 in medicine: a new twist to sustain inhibition of his cytokine tin the therapy of Pulmonary Arterial Hypertension

Potential Role of Hesperidin in Improving Experimental Pulmonary Arterial Hypertension in Rats via Modulation of the NF-κB Pathway

This study was designed to evaluate the therapeutic effects of hesperidin, an anti-inflammatory compound, on pulmonary arterial hypertension (PAH). A PAH rat model was established using monocrotaline (MCT, 60 mg/kg). Next, the experimental animals were assigned into the following four groups (n = 6 per group): Control group, MCT group, MCT + H20 group (20 mg/kg hesperidin), and MCT + H40 group (40 mg/kg hesperidin). According to the experimental outcomes, the PAH rat model was built successfully. In PAH animals, hesperidin significantly reduced right ventricular systolic pressure, Fulton index, and mean pulmonary arterial pressure. Concurrently, it improved pulmonary artery velocity-time integral and acceleration time, as well as alleviated pulmonary artery and right ventricular remodeling. On a molecular level, hesperidin inhibited the expression of vascular endothelial-cadherin, alpha-smooth muscle actin, matrix metalloproteinase-9, and transforming growth factor beta. Also, hesperidin downregulated pro-inflammatory cytokines such as interleukin (IL)-6, IL-1β, IL-18, chemokine C-C motif ligand 2, and C-X-C motif chemokine ligand 1 levels, and reduced the number of CD68+ cells in tissue samples. Further analysis revealed that hesperidin could inhibit the activation of p-IκB-α and p-p65 in samples induced by MCT. Collectively, these findings suggest that hesperidin may inhibit inflammation through the NF-κB pathway, thereby improving experimental PAH in rats induced by MCT.

Cannabidiol may prevent the development of congestive hepatopathy secondary to right ventricular hypertrophy associated with pulmonary hypertension in rats

BACKGROUND

Pulmonary hypertension (PH) can cause right ventricular (RV) failure and subsequent cardiohepatic syndrome referred to as congestive hepatopathy (CH). Passive blood stasis in the liver can affect inflammation, fibrosis, and ultimately cirrhosis. Cannabidiol (CBD) has many beneficial properties including anti-inflammatory and reduces RV systolic pressure and RV hypertrophy in monocrotaline (MCT)-induced PH in rats. Thus, it suggests that CBD may have the potential to limit CH development secondary to RV failure. The present study aimed to determine whether chronic administration of CBD can inhibit the CH secondary to RV hypertrophy associated with MCT-induced PH.

METHODS

The experiments involved rats with and without MCT-induced PH. CBD (10 mg/kg) or its vehicle was administered once daily for 3 weeks after MCT injection (60 mg/kg).

RESULTS

Monocrotaline administration increased the liver/body weight ratio. In histology examinations, we observed necrosis and vacuolar degeneration of hepatocytes as well as sinusoidal congestion. In biochemical studies, we observed increased levels of nuclear factor-κappa B (NF-κB), tumour necrosis factor-alpha (TNA-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6). CBD administration to PH rats reduced the liver/body weight ratio, improved the architecture of the liver, and inhibited the formation of necrosis. Cannabidiol also decreased the level of NF-κB, TNF-α, IL-1β and IL-6.

CONCLUSIONS

The studies show that CBD can protect the liver from CH probably through attenuating PH, protective effects on the RV, and possibly direct anti-inflammatory effects on liver tissue through regulation of the NF-κB pathway.

Targeting IL-11 system as a treatment of pulmonary arterial hypertension

IL-11 is linked to fibrotic diseases, but its role in pulmonary hypertension is unclear. We examined IL-11's involvement in idiopathic pulmonary arterial hypertension (iPAH). Using samples from control (n = 20) and iPAH (n = 6) subjects, we assessed IL-11 and IL-11Rα expression and localization through RT-qPCR, ELISA, immunohistochemistry, and immunofluorescence. A monocrotaline-induced PAH model helped evaluate the impact of siRNA-IL-11 on pulmonary artery remodeling and PH. The effects of recombinant human IL-11 and IL-11Rα on human pulmonary artery smooth muscle cell (HPASMC) proliferation, pulmonary artery endothelial cell (HPAEC) mesenchymal transition, monocyte interactions, endothelial tube formation, and precision cut lung slice (PCLS) pulmonary artery remodeling and contraction were evaluated. IL-11 and IL-11Rα were over-expressed in pulmonary arteries (3.2-fold and 75-fold respectively) and serum (1.5-fold and 2-fold respectively) of patients with iPAH. Therapeutic transient transfection with siRNA targeting IL-11 resulted in a significant reduction in pulmonary artery remodeling (by 98%), right heart hypertrophy (by 66%), and pulmonary hypertension (by 58%) in rats exposed to monocrotaline treatment. rhIL-11 and soluble rhIL-11Rα induce HPASMC proliferation and HPAEC to monocyte interactions, mesenchymal transition, and tube formation. Neutralizing monoclonal IL-11 and IL-11Rα antibodies inhibited TGFβ1 and EDN-1 induced HPAEC to mesenchymal transition and HPASMC proliferation. In 3D PCLS, rhIL-11 and soluble rhIL-11Rα do not promote pulmonary artery contraction but sensitize PCLS pulmonary artery contraction induced by EDN-1. In summary, IL-11 and IL-11Rα are more highly expressed in the pulmonary arteries of iPAH patients and contribute to pulmonary artery remodeling and the development of PH.