Pulmonary arterial hypertension (PAH) is a chronic disease that is characterized as mean pulmonary artery hypertension (mPAP) > 25 mmHg. PAH is caused by progressive obliteration of small pulmonary arteries due to known or unknown etiologies. The effect of traditional therapy is suboptimal because it can only improve symptoms but cannot cure the disease, and therefore, scientists have turned their attention to stem cell therapy for efficacious treatments. In recent years, accumulating evidences have demonstrated that endothelial progenitor cells (EPCs) and mesenchymal stem cells (MSCs) are closely related with the occurrence of PAH and have the ability to prevent and reverse this disease. In this review, we turn our attention to a novel therapy for PAH, stem cell therapy, through comparing effect of preclinical research on cells and animals and evaluating the feasibility and potential difficulties of clinical application.

Background and Purpose As of 5 March 2021, coronavirus disease 2019 (COVID-19) has infected more than 116 million people worldwide, with over 91 million convalescent patients. A decrease in function of multiple organs has been reported in recovering patients. In China, traditional Chinese medicine (TCM) is recommended to treat patients in the rehabilitation period; however, its efficacy and safety still need to be confirmed. Experimental Approach We conducted a multicentre, double-blind, randomised controlled trial that recruited patients with COVID-19 during the rehabilitation period. In total, 131 patients were randomly divided into two groups: 66 in the Bufei Huoxue capsules (BFHX)-treated group and 65 in the control group. BFHX was administered orally three times a day (1.4g/dose) for 90 days, and the control group was administered placebo for 90 days. The primary endpoint was to evaluate improvements in fatigue symptoms and exercise tolerance. Key Results After three months of treatment, the six-minute walk distance (6MWD) of the BFHX-treated group was significantly longer than that of the control group, compared to baseline. The Fatigue Assessment Inventory (FAI) was lower in the BFHX-treated group than in the control group. Adverse event rates were higher in the BFHX-treated group, but there was no statistical difference between groups. Conclusions and Implications BFHX may have strong rehabilitative effects on patients recovering from COVID-19 in terms of improvements in physiological activities, such as fatigue symptoms and exercise tolerance. The drug has proven to have favourable safety and effectiveness profiles.

Background and Purpose: Piezo1 is a crucial mechanical sensitive channel involved in vascular remodeling. However, the role of Piezo1 in different types of vascular cells during the development of pulmonary hypertension (PH) induced by high flow is largely unknown. Experimental Approach: Based on previously established protocols, we established a rat PH model by left pulmonary artery ligation (LPAL) for 2 and 5 weeks to mimic the high flow and hemodynamic stress. Key Results: Results showed that right ventricular systolic pressure (RVSP) and right ventricular wall thickness were significantly increased in the LPAL groups compared with the SHAM group. Rats in LPAL-5w groups developed remarkable pulmonary vascular remodeling, resulting in decreased phenylephrine-induced contraction and acetylcholine-induced relaxation. On the one hand, in pulmonary arterial smooth muscle cells (PASMCs), upregulation of Piezo1 was observed in association with the elevation of [Ca2+]cyt in the PASMCs from both LPAL-2w and LPAL-5w groups versus respective SHAM groups. Notably, Piezo1 expression was directly upregulated by YAP/TEAD4. On the other hand, significantly upregulated Piezo1 expression was also presented in the lung tissues, mostly composed of pulmonary endothelial cells (ECs), from rats of LPAL-2w and -5ws groups, which can be transcriptionally regulated by RELA (p65) and contributes to the lung inflammation. Conclusion and Implications: Our results suggested the upregulation of Piezo1 in both PASMCs and ECs, coordinate together and contribute to the pulmonary vascular remodeling and dysfunction in LPAL-PH rats, providing novel insights into the cell type-specific effects of Piezo1 in the pulmonary vasculature during high flow-related PH.

Pulmonary hypertension (PH) is a severe pathophysiological condition characterized by pulmonary artery remodeling and continuous increase in pulmonary artery pressure, which eventually develops to right heart failure and death. Though newly discovered and incredible treatment strategies in recent years have improved the prognosis of PH, the fact that limited types of effective and economical drugs for PH is available still makes it as a life-threatening disease. Some drugs from Chinese Materia Medica are traditionally applied in treating lung diseases. Accumulating evidence suggests the active pharmaceutical ingredients (APIs) derived from those medicines have brought prospective future for prevention and treatment of PH. In this review, we summarized the pharmacological effects of APIs derived from CMM which is potent in treating PH, aiming at bringing new ideas in initial drug discovery and identification of potential therapeutic strategies in alternative medicine for PH.