Catheter-based therapies for patients with medication-refractory pulmonary arterial hypertension

High-intensity Focused Ultrasound-A New Choice to Conduct Pulmonary Artery Denervation

This research aimed to explore whether high-intensity focused ultrasound (HIFU) could conduct pulmonary artery denervation (PADN). HIFU was performed in pulmonary arteries of 6 normotensive rabbits at dose of 250W, 6 times for each rabbit, and an additional 6 rabbits served as controls. Then ATEPH was induced in both groups by intravenous infusion of autogeneic thrombus. Hemodynamics and ultrasonography parameters were measured by right heart catheter and echocardiography pre- and post-establishment of ATEPH models in both groups. Histological analysis and immunohistochemistry of tyrosine hydroxylase (TH) were also performed. After PADN procedures, 5 rabbits were successfully conducted PADN, of which ablation zone was also observed in right auricle or right lung in 4 rabbits. Ablation zone was detected only in right lung in 1 rabbit. Compared with control group, milder right heart hemodynamic changes were found in PADN group, accompanied by improved ultrasound parameters in PADN group. HIFU can acutly damage SNs around pulmonary artery successfully, which may be a new choice to conduct PADN. However, the accuracy of HIFU with PADN needs to be improved.

Computer simulation of surgical interventions for the treatment of refractory pulmonary hypertension

This paper describes computer models of three interventions used for treating refractory pulmonary hypertension (RPH). These procedures create either an atrial septal defect, a ventricular septal defect or, in the case of a Potts shunt, a patent ductus arteriosus. The aim in all three cases is to generate a right-to-left shunt, allowing for either pressure or volume unloading of the right side of the heart in the setting of right ventricular failure, while maintaining cardiac output. These shunts are created, however, at the expense of introducing de-oxygenated blood into the systemic circulation, thereby lowering the systemic arterial oxygen saturation. The models developed in this paper are based on compartmental descriptions of human hemodynamics and oxygen transport. An important parameter included in our models is the cross-sectional area of the surgically created defect. Numerical simulations are performed to compare different interventions and various shunt sizes and to assess their impact on hemodynamic variables and oxygen saturations. We also create a model for exercise and use it to study exercise tolerance in simulated pre-intervention and post-intervention RPH patients.

Knockdown of Long Noncoding RNA (lncRNA) AK094457 Relieved Angiotensin II Induced Vascular Endothelial Cell Injury

Background

Hypertension could induce many serious diseases, including damage to vascular endothelial cells. As a non-coding RNA, long noncoding RNA (lncRNA) has received much attention in scientific research and has a regulating efficacy on many critical life activities in human body. The level of lncRNA AK094457 is thought to be elevated in hypertensive rats. However, there is no research indicating the relationship between the level of lncRNA AK094457 and vascular endothelial injury.

Material/Methods

In our study, we used lentiviral to knockdown lncRNA AK094457, and the human umbilical vein endothelial cells (HUVECs) were stimulated by the Ang II to imitate the vascular endothelial cell damage caused by hypertension. The Cell Counting Kit-8 assays were used to detect the cells viability. Western blotting was performed to detect the endothelial nitric oxide synthase (eNOS), p-eNOS and endothelin-1 (ET-1). After that the production of the NO was monitored. At last, the reactive oxygen species (ROS) levels and apoptosis rates were detected in this study.

Results

According to the results, we found that knockdown lncRNA AK094457 could alleviate the decrease of vascular endothelial cell viability induced by angiotensin II (Ang II). The knockdown of lncRNA AK094457 also relieved the downregulation of eNOS and p-eNOS, and the decreasing of NO release. At the same time, the knockdown of lncRNA inhibited the levels of Ang II-induced proinflammatory cytokines (tumor necrosis factor [TNF]-α, interleukin [IL]-1, and IL-6) and cell adhesion molecules (vascular cell adhesion molecule 1 [VCAM-1], intercellular adhesion molecule 1 [ICAM-1], and monocyte chemoattractant protein-1 [MCP-1]). The levels of ROS and apoptosis rates also decreased after the knockdown of lncRNA AK094457.

Conclusions

All these results indicated that lncRNA AK094457 could promote Ang II-induced vascular endothelial cell injury. On the contrary, knockdown of lncRNA AK094457 could alleviate this damage.

A potential risk factor of essential hypertension in case-control study: MicroRNAs miR-10a-5p

Background: Essential hypertension is a multifactorial disease with high morbidity. The researches on the influence of genes on the disease are still in its infancy, and the mechanism of gene regulation is not clear. MiRNAs are key molecules that regulate the expression control of protein-coding or protein-non-coding RNA. It may be an important biological molecule risk factor for essential hypertension.Methods: A case-control study with 98 EH and 98 non-EH was conducted in our experiment. The candidate miRNAs including miR-10a-5p and miR-497-5p were detected and verified by qRT-PCR.Results: The expression level of miRNA in EH cases was significantly lower than the healthy control (P = 0.005). In addition, the relative expression of miR-10a-5p was closely positive correlated with DBP (r = 0.162, P = 0.023) and SBP (r = 0.223, P = 0.002). After adjusting confound factors, the result of the logistic regression indicated that hypo-expression of miR-10a-5p is a risk factor for EH (OR(95%CI) = 1.676(1.302,2.157), adjusted P < 0.0001). And the ROC analysis shows that the combined line with BMI and miR-10a-5p was a values marker for EH (AUC: 0.728, P < 0.0001).Conclusions: Lower expression of miR-10a-5p, as the key role, is significantly related to the risk of EH and maybe as a potential biomolecule for EH.

Interventional Therapies in Pulmonary Hypertension

Despite advances in drug therapy, pulmonary hypertension-particularly arterial hypertension (PAH)-remains a fatal disease. Untreatable right heart failure (RHF) from PAH eventually ensues and remains a significant cause of death in these patients. Lowering pulmonary input impedance with different PAH-specific drugs is the obvious therapeutic target in RHF due to chronically increased afterload. However, potential clinical gain can also be expected from attempts to unload the right heart and increase systemic output. Atrial septostomy, Potts anastomosis, and pulmonary artery denervation are interventional procedures serving this purpose. Percutaneous balloon pulmonary angioplasty, another interventional therapy, has re-emerged in the last few years as a clear alternative for the management of patients with distal, inoperable, chronic thromboembolic pulmonary hypertension. The current review discusses the physiological background, experimental evidence, and potential clinical and hemodynamic benefits of all these interventional therapies regarding their use in the setting of RHF due to severe pulmonary hypertension.

Overexpression of microRNA-506-3p aggravates the injury of vascular endothelial cells in patients with hypertension by downregulating Beclin1 expression

The aim of the present study was to measure the expression of microRNA (miRNA)-506-3p in the peripheral blood of patients with hypertension and to determine the biological functions and mechanisms of action of miR-506-3p. A total of 61 patients with primary hypertension were included in the present study. Peripheral blood was collected from all patients, as well as 31 healthy subjects who were included in a control group. The expression of miR-506-3p in peripheral blood was determined by reverse transcription-quantitative polymerase chain reaction. Human umbilical vein endothelial cells (HUVECs) were transfected with miR-506-3p mimics or miR-506-3p inhibitor. The proliferation and migration of HUVECs were determined using cell-counting kit 8 and Transwell assays, respectively. The cell cycle and apoptosis of HUVECs were detected by flow cytometry. The expression of Beclin1 (BECN1) protein, a potential target of miR-506-3p, was measured using western blotting. A dual-luciferase reporter assay was performed to determine the interaction between BECN1 and miR-506-3p. It was demonstrated that miR-506-3p expression in the peripheral blood of patients with patients was upregulated and dependent on the severity of hypertension. miR-506-3p overexpression inhibited the proliferation and migration of HUVECs. In addition, miR-506-3p inhibited the transition from the G1 phase to the S-phase in HUVECs. Overexpression of miR-506-3p promoted the apoptosis of HUVECs. Notably, miR-506-3p downregulated the expression of BECN1 by directly binding to its 3′-untranslated region. The present study demonstrated that miR-506-3p expression is elevated in the peripheral blood of patients with hypertension and is associated with the severity of hypertension. By downregulating BECN1 expression, miR-506-3p aggravates injury in vascular endothelial cells by inhibiting the proliferation and migration of HUVECs, as well as promoting their apoptosis.

Molecular mechanisms in vascular injury induced by hypertension: Expression and role of microRNA-34a

The aim of the present study was to investigate the expression and function of microRNA (miR)-34a in patients with primary hypertension. The expression of miR-34a was measured in the peripheral blood of 50 patients with primary hypertension and 28 normal controls by reverse transcription quantitative polymerase chain reaction. In addition, human umbilical vein endothelial cells (HUVECs) were transfected with an miR-34a inhibitor to suppress the expression of miR-34a, and the proliferation, migration and cell cycle distribution of HUVECs were measured by Cell Counting Kit-8, Transwell and flow cytometry assays. The target of miR-34a was also predicted by bioinformatics analysis and verified by a dual-luciferase reporter gene assay and western blot analysis. miR-34a was significantly upregulated in the peripheral blood of patients with hypertension when compared with controls (P<0.05), and upregulation of miR-34a was associated with a higher clinical stage of hypertension (phase III; P<0.05). In vitro experiments demonstrated that inhibition of miR-34a promoted the proliferation, migration and G1/S transition of HUVECs, relative to scramble-miR controls (P<0.05). Furthermore, transforming growth factor β-induced factor homeobox 2 (TIGF2) was predicted and verified to be a direct target of miR-34a. Collectively, these data suggested that miR-34a was upregulated in the peripheral blood of patients with hypertension, and that upregulated miR-34a may promote vascular endothelial injury by targeting TIGF2.