Sodium tanshinone IIA sulfonate inhibits canonical transient receptor potential expression in pulmonary arterial smooth muscle from pulmonary hypertensive rats

Sodium tanshinone IIA sulfonate protects vascular relaxation in ApoE-knockout mice by inhibiting the SYK-NLRP3 inflammasome-MMP2/9 pathway

BACKGROUND

Hyperlipidemia damages vascular wall and serves as a foundation for diseases such as atherosclerosis, hypertension and stiffness. The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is implicated in vascular dysfunction associated with hyperlipidemia-induced vascular injury. Sodium tanshinone IIA sulfonate (STS), a well-established cardiovascular protective drug with recognized anti-inflammatory, antioxidant, and vasodilatory properties, is yet to be thoroughly investigated for its impact on vascular relaxant imbalance induced by hyperlipidemia.

METHODS

In this study, we treated ApoE-knockout (ApoE-/-) mouse with STS and assessed the activation of the NLRP3 inflammasome, expression of MMP2/9, integrity of elastic fibers, and vascular constriction and relaxation.

RESULTS

Our findings reveal that STS intervention effectively preserves elastic fibers, significantly restores aortic relaxation function in ApoE-/- mice, and reduces their excessive constriction. Furthermore, STS inhibits the phosphorylation of spleen tyrosine kinase (SYK), suppresses NLRP3 inflammasome activation, and reduces MMP2/9 expression.

CONCLUSIONS

These results demonstrate that STS protects vascular relaxation against hyperlipidemia-induced damage through modulation of the SYK-NLRP3 inflammasome-MMP2/9 pathway. This research provides novel insights into the mechanisms underlying vascular relaxation impairment in a hyperlipidemic environment and uncovers a unique mechanism by which STS preserves vascular relaxation, offering valuable foundational research evidence for its clinical application in promoting vascular health.

A systematic review and meta-analysis on sodium tanshinone IIA sulfonate injection for the adjunctive therapy of pulmonary heart disease

AIMS

Sodium tanshinone IIA sulfonate (STS) injection has been widely used as adjunctive therapy for pulmonary heart disease (PHD) in China. Nevertheless, the efficacy of STS injection has not been systematically evaluated so far. Hence, the efficacy of STS injection as adjunctive therapy for PHD was explored in this study.

METHODS

Randomized controlled trials (RCTs) were screened from China Science and Technology Journal Database, China National Knowledge Infrastructure, Wanfang Database, PubMed, Sino-Med, Google Scholar, Medline, Chinese Biomedical Literature Database, Cochrane Library, Embase and Chinese Science Citation Database until 20 January 2024. Literature searching, data collection and quality assessment were independently performed by two investigators. The extracted data was analyzed with RevMan 5.4 and STATA 14.0. Basing on the methodological quality, dosage of STS injection, control group measures and intervention time, sensitivity analysis and subgroup analysis were performed.

RESULTS

19 RCTs with 1739 patients were included in this study. Results showed that as adjunctive therapy, STS injection combined with Western medicine showed better therapeutic efficacy than Western medicine alone for PHD by increasing the clinical effective rate (RR = 1.22; 95% CI, 1.17 to 1.27; p < 0.001), partial pressure of oxygen (MD = 10.16; 95% CI, 5.07 to 15.24; p < 0.001), left ventricular ejection fraction (MD = 8.66; 95% CI, 6.14 to 11.18; p < 0.001) and stroke volume (MD = 13.10; 95% CI, 11.83 to 14.38; p < 0.001), meanwhile decreasing the low shear blood viscosity (MD = -1.16; 95% CI, -1.57 to -0.74; p < 0.001), high shear blood viscosity (MD = -0.64; 95% CI, -0.86 to -0.42; p < 0.001), plasma viscosity (MD = -0.23; 95% CI, -0.30 to -0.17; p < 0.001), hematokrit (MD = -8.52; 95% CI, -11.06 to -5.98; p < 0.001), fibrinogen (MD = -0.62; 95% CI, -0.87 to -0.37; p < 0.001) and partial pressure of carbon dioxide (MD = -8.56; 95% CI, -12.09 to -5.02; p < 0.001).

CONCLUSION

STS injection as adjunctive therapy seemed to be more effective than Western medicine alone for PHD. However, due to low quality of the included RCTs, more well-designed RCTs were necessary to verify the efficacy of STS injection.

Screening of rosmarinic acid from Salvia miltiorrhizae acting on the novel target TRPC1 based on the 'homology modelling-virtual screening-molecular docking-affinity assay-activity evaluation' method

CONTEXT

Salvia miltiorrhizae Bunge (Lamiaceae) is a traditional Chinese medicine (TCM) for the treatment of 'thoracic obstruction'. Transient receptor potential canonical channel 1 (TRPC1) is a important target for myocardial injury treatment.

OBJECTIVE

This work screens the active component acting on TRPC1 from Salvia miltiorrhizae.

MATERIALS AND METHODS

TCM Systems Pharmacology Database and Analysis Platform (TCMSP) was used to retrieve Salvia miltiorrhiza compounds for preliminary screening by referring to Lipinski's rule of five. Then, the compound group was comprehensively scored by AutoDock Vina based on TRPC1 protein. Surface plasmon resonance (SPR) was used to determine the affinity of the optimal compound to TRPC1 protein. Western blot assay was carried out to observe the effect of the optimal compound on TRPC1 protein expression in HL-1 cells, and Fura-2/AM detection was carried out to observe the effect of the optimal compound on calcium influx in HEK293 cells.

RESULTS

Twenty compounds with relatively good characteristic parameters were determined from 202 compounds of Salvia miltiorrhiza. Rosmarinic acid (RosA) was obtained based on the molecular docking scoring function. RosA had a high binding affinity to TRPC1 protein (KD value = 1.27 µM). RosA (50 μM) could reduce the protein levels (417.1%) of TRPC1 after oxygen-glucose deprivation/reperfusion (OGD/R) in HL-1 cells and it could inhibit TRPC1-mediated Ca²⁺ influx injury (0.07 ΔRatio340/380) in HEK293 cells.

DISCUSSION AND CONCLUSIONS

We obtained the potential active component RosA acting on TRPC1 from Salvia miltiorrhizae, and we speculate that RosA may be a promising clinical candidate for myocardial injury therapy.

Unleashing the Potential of Nrf2: A Novel Therapeutic Target for Pulmonary Vascular Remodeling

Pulmonary vascular remodeling, characterized by the thickening of all three layers of the blood vessel wall, plays a central role in the pathogenesis of pulmonary hypertension (PH). Despite the approval of several drugs for PH treatment, their long-term therapeutic effect remains unsatisfactory, as they mainly focus on vasodilation rather than addressing vascular remodeling. Therefore, there is an urgent need for novel therapeutic targets in the treatment of PH. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a vital transcription factor that regulates endogenous antioxidant defense and emerges as a novel regulator of pulmonary vascular remodeling. Growing evidence has suggested an involvement of Nrf2 and its downstream transcriptional target in the process of pulmonary vascular remodeling. Pharmacologically targeting Nrf2 has demonstrated beneficial effects in various diseases, and several Nrf2 inducers are currently undergoing clinical trials. However, the exact potential and mechanism of Nrf2 as a therapeutic target in PH remain unknown. Thus, this review article aims to comprehensively explore the role and mechanism of Nrf2 in pulmonary vascular remodeling associated with PH. Additionally, we provide a summary of Nrf2 inducers that have shown therapeutic potential in addressing the underlying vascular remodeling processes in PH. Although Nrf2-related therapies hold great promise, further research is necessary before their clinical implementation can be fully realized.

Identification of tanshinone I as cap-dependent endonuclease inhibitor with broad-spectrum antiviral effect

IMPORTANCE

The spread of avian-borne, tick-borne, and rodent-borne pathogens has the potential to pose a serious threat to human health, and candidate vaccines as well as therapeutics for these pathogens are urgently needed. Tanshinones, especially tanshinone I, were identified as a cap-dependent endonuclease inhibitor with broad-spectrum antiviral effects on negative-stranded, segmented RNA viruses including bandavirus, orthomyxovirus, and arenavirus from natural products, implying an important resource of candidate antivirals from the traditional Chinese medicines. This study supplies novel candidate antivirals for the negative-stranded, segmented RNA virus and highlights the endonuclease involved in the cap-snatching process as a reliable broad-spectrum antiviral target.

Aloperine protects pulmonary hypertension via triggering PPARγ signaling and inhibiting calcium regulatory pathway in pulmonary arterial smooth muscle cells

Previous studies have reported the beneficial role of Aloperine (ALO), an active vasodilator purified from the seeds and leaves of the herbal plant Sophora alopecuroides L., on experimental pulmonary hypertension (PH); however, detailed mechanisms remain unclear. In this study, monocrotaline-induced PH (MCT-PH) rat model and primarily cultured rat distal pulmonary arterial smooth muscle cells (PASMCs) were used to investigate the mechanisms of ALO on experimental PH, pulmonary vascular remodeling, and excessive proliferation of PASMCs. Results showed that first, ALO significantly prevented the disease development of MCT-PH by inhibiting right ventricular systolic pressure (RVSP) and right ventricular hypertrophy indexed by the Fulton Index, normalizing the pulmonary arterials (PAs) remodeling and improving the right ventricular function indexed by transthoracic echocardiography. ALO inhibited the excessive proliferation of both PAs and PASMCs. Then, isometric tension measurements showed vasodilation of ALO on precontracted PAs isolated from both control and MCT-PH rats via activating the KCNQ channel, which was blocked by specific KCNQ potassium channel inhibitor linopirdine. Moreover, by using immunofluorescence staining and nuclear/cytosol fractionation, we further observed that ALO significantly enhanced the PPARγ nuclear translocation and activation in PASMCs. Transcriptome analyses also revealed activated PPARγ signaling and suppressed calcium regulatory pathway in lungs from MCT-PH rats treated with ALO. In summary, ALO could attenuate MCT-PH through both transient vasodilation of PAs and chronic activation of PPARγ signaling pathway, which exerted antiproliferative roles on PASMCs and remodeled PAs.NEW & NOTEWORTHY Aloperine attenuates monocrotaline-induced pulmonary hypertension (MCT-PH) in rats by inhibiting the pulmonary vascular remodeling and proliferation of pulmonary arterial smooth muscle cells (PASMCs). In mechanism, Aloperine not only exerts a transient KCNQ-dependent vasodilation in precontracted pulmonary arteries (PAs) from both control and MCT-PH rats but also activates PPARγ nuclear translocation and signaling transduction in PASMCs, which chronically inhibits the calcium regulatory pathway and proliferation of PASMCs.

Natural Products for the Treatment of Pulmonary Hypertension: Mechanism, Progress, and Future Opportunities

Pulmonary hypertension (PH) is a lethal disease due to the remodeling of pulmonary vessels. Its pathophysiological characteristics include increased pulmonary arterial pressure and pulmonary vascular resistance, leading to right heart failure and death. The pathological mechanism of PH is complex and includes inflammation, oxidative stress, vasoconstriction/diastolic imbalance, genetic factors, and ion channel abnormalities. Currently, many clinical drugs for the treatment of PH mainly play their role by relaxing pulmonary arteries, and the treatment effect is limited. Recent studies have shown that various natural products have unique therapeutic advantages for PH with complex pathological mechanisms owing to their multitarget characteristics and low toxicity. This review summarizes the main natural products and their pharmacological mechanisms in PH treatment to provide a useful reference for future research and development of new anti-PH drugs and their mechanisms.

Preparation and performance of random- and oriented-fiber membranes with core-shell structures via coaxial electrospinning

The cells and tissue in the human body are orderly and directionally arranged, and constructing an ideal biomimetic extracellular matrix is still a major problem to be solved in tissue engineering. In the field of the bioresorbable vascular grafts, the long-term functional prognosis requires that cells first migrate and grow along the physiological arrangement direction of the vessel itself. Moreover, the graft is required to promote the formation of neointima and the development of the vessel walls while ensuring that the whole repair process does not form a thrombus. In this study, poly (l-lactide-co-ε-caprolactone) (PLCL) shell layers and polyethylene oxide (PEO) core layers with different microstructures and loaded with sodium tanshinone IIA sulfonate (STS) were prepared by coaxial electrospinning. The mechanical properties proved that the fiber membranes had good mechanical support, higher than that of the human aorta, as well as great suture retention strengths. The hydrophilicity of the oriented-fiber membranes was greatly improved compared with that of the random-fiber membranes. Furthermore, we investigated the biocompatibility and hemocompatibility of different functional fiber membranes, and the results showed that the oriented-fiber membranes containing sodium tanshinone IIA sulfonate had an excellent antiplatelet adhesion effect compared to other fiber membranes. Cytological analysis confirmed that the functional fiber membranes were non-cytotoxic and had significant cell proliferation capacities. The oriented-fiber membranes induced cell growth along the orientation direction. Degradation tests showed that the pH variation range had little change, the material mass was gradually reduced, and the fiber morphology was slowly destroyed. Thus, results indicated the degradation rate of the oriented-fiber graft likely is suitable for the process of new tissue regeneration, while the random-fiber graft with a low degradation rate may cause the material to reside in the tissue for too long, which would impede new tissue reconstitution. In summary, the oriented-functional-fiber membranes possessing core-shell structures with sodium tanshinone IIA sulfonate/polyethylene oxide loading could be used as tissue engineering materials for applications such as vascular grafts with good prospects, and their clinical application potential will be further explored in future research.

Network Pharmacology and Molecular Docking Analysis of Shufeiya Recipe in the Treatment of Pulmonary Hypertension

Objective

This study is aimed at exploring the molecular mechanism of Shufeiya recipe in the treatment of pulmonary hypertension (PH) using network pharmacology and molecular docking analysis.

Methods

Active components and their target proteins in the recipe were screened using the TCMSP database. PH-related core proteins were screened using GeneCards, STRING database, and Cytoscape-v3.8.2. Common proteins were obtained by intersection of the target proteins of these recipe active components and pH-related core proteins. Rx64 4.0.2 software was used to perform GO functional enrichment analysis and KEGG pathway enrichment analysis on the common proteins to obtain pathway-enriched proteins, and then core enriched proteins were further screened. We analyzed the relationship between the active components and pathway-enriched proteins using Cytoscape-v3.8.2. AutoDock Vina was used to dock their core proteins into the components.

Results

Shufeiya recipe contained 67 active components. 61 common proteins of the target proteins of the active components and PH-related core proteins were obtained. The treatment involved both functional and pathway regulations. The core pathway-enriched proteins were prostaglandin G/H synthase 2 (PTGS2), epidermal growth factor receptor (EGFR), and RAC-alpha serine/threonine-protein kinase (AKT1), and their binding energies to the corresponding components were all less than -5 kJ•mol-1.

Conclusion

It was found that the main mechanism might be the active components acting on the core pathway-enriched proteins to regulate related signaling pathways, thereby playing roles in anticoagulation, vasodilation, anti-PASMC proliferation, promotion of PAECs apoptosis, inhibition of oxidative stress, and anti-inflammatory effects.

Deletion of classical transient receptor potential 1, 3 and 6 alters pulmonary vasoconstriction in chronic hypoxia-induced pulmonary hypertension in mice

Chronic hypoxia-induced pulmonary hypertension (CHPH) is a severe disease that is characterized by increased proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs) leading to pulmonary vascular remodeling. The resulting increase in pulmonary vascular resistance (PVR) causes right ventricular hypertrophy and ultimately right heart failure. In addition, increased PVR can also be a consequence of hypoxic pulmonary vasoconstriction (HPV) under generalized hypoxia. Increased proliferation and migration of PASMCs are often associated with high intracellular Ca²⁺ concentration. Recent publications suggest that Ca²⁺-permeable nonselective classical transient receptor potential (TRPC) proteins-especially TRPC1 and 6-are crucially involved in acute and sustained hypoxic responses and the pathogenesis of CHPH. The aim of our study was to investigate whether the simultaneous deletion of TRPC proteins 1, 3 and 6 protects against CHPH-development and affects HPV in mice. We used a mouse model of chronic hypoxia as well as isolated, ventilated and perfused mouse lungs and PASMC cell cultures. Although right ventricular systolic pressure as well as echocardiographically assessed PVR and right ventricular wall thickness (RVWT) were lower in TRPC1, 3, 6-deficient mice, these changes were not related to a decreased degree of pulmonary vascular muscularization and a reduced proliferation of PASMCs. However, both acute and sustained HPV were almost absent in the TRPC1, 3, 6-deficient mice and their vasoconstrictor response upon KCl application was reduced. This was further validated by myographical experiments. Our data revealed that 1) TRPC1, 3, 6-deficient mice are partially protected against development of CHPH, 2) these changes may be caused by diminished HPV and not an altered pulmonary vascular remodeling.

Sodium tanshinone IIA sulfonate enhances the BMP9-BMPR2-Smad1/5/9 signaling pathway in rat pulmonary microvascular endothelial cells and human embryonic stem cell-derived endothelial cells

BACKGROUND

Recent studies have demonstrated the beneficial effects of STS in treating pulmonary hypertension by inhibiting the pulmonary vascular remodeling and suppressing the abnormally elevated proliferation and migration of PASMCs. However, the roles of STS on pulmonary vascular endothelium remain largely known.

METHODS

In this study, we investigated the effects and mechanisms of STS on pulmonary vascular endothelial dysfunction by using a chronic hypoxia-induced pulmonary hypertension (HPH) rat model, as well as in primarily cultured rat PMVECs and human ESC-ECs cell models.

RESULTS

Firstly, a 21-day treatment of STS significantly prevents the disease development of HPH by normalizing the right ventricular systolic pressure and right ventricular hypertrophy, improving the cardiac output. Then, STS treatment markedly inhibits the hypoxia-induced medial wall thickening of the distal intrapulmonary arteries. Notably, STS significantly inhibits the hypoxia-induced apoptosis in both the pulmonary endothelium of HPH rats and primarily cultured PMVECs, through the stabilization of BMPR2 protein and protection of the diminished BMP9-BMPR2-Smad1/5/9 signaling pathway. In mechanism, STS treatment retrieves the hypoxic downregulation of BMPR2 by stabilizing the BMPR2 protein, inhibiting the BMPR2 protein degradation via lysosome system, and promoting the plasma membrane localization of BMPR2, all of which together reinforcing the BMP9-induced signaling transduction in both PMVECs and human ESC-ECs. However, these effects are absent in hESC-ECs expressing heterozygous dysfunctional BMPR2 protein (BMPR2^+/R899X).

CONCLUSION

STS may exert anti-apoptotic roles, at least partially, via induction of the BMP9-BMPR2-Smad1/5/9 signaling transduction in pulmonary endothelium and PMVECs.

Traditional Herbal Medicine Discovery for the Treatment and Prevention of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is characterized by pulmonary artery remodeling that may subsequently culminate in right heart failure and premature death. Although there are currently both non-pharmacological (lung transplantation, etc.) and pharmacological (Sildenafil, Bosentan, and new oral drugs on trial) therapies available, PAH remains a serious and fatal pulmonary disease. As a unique medical treatment, traditional herbal medicine (THM) treatment has gradually exerted its advantages in treating PAH worldwide through a multi-level and multi-target approach. Additionally, the potential mechanisms of THM were deciphered, including suppression of proliferation and apoptosis of pulmonary artery smooth muscle cells, controlling the processes of inflammation and oxidative stress, and regulating vasoconstriction and ion channels. In this review, the effects and mechanisms of the frequently studied compound THM, single herbal preparations, and multiple active components from THM are comprehensively summarized, as well as their related mechanisms on several classical preclinical PAH models. It is worth mentioning that sodium tanshinone IIA sulfonate sodium and tetramethylpyrazine are under clinical trials and are considered the most promoting medicines for PAH treatment. Last, reverse pharmacology, a strategy to discover THM or THM-derived components, has also been proposed here for PAH. This review discusses the current state of THM, their working mechanisms against PAH, and prospects of reverse pharmacology, which are expected to facilitate the natural anti-PAH medicine discovery and development and its bench-to-bedside transformation.

NF-κB/p65 Competes With Peroxisome Proliferator-Activated Receptor Gamma for Transient Receptor Potential Channel 6 in Hypoxia-Induced Human Pulmonary Arterial Smooth Muscle Cells

Objective: Peroxisome proliferator-activated receptor gamma (PPARγ) has an anti-proliferation effect on pulmonary arterial smooth muscle cells (PASMCs) via the transient receptor potential channel (TRPC) and protects against pulmonary artery hypertension (PAH), whereas nuclear factor-kappa B (NF-κB) has pro-proliferation and pro-inflammation effects, which contributes to PAH. However, the association between them in PAH pathology remains unclear. Therefore, this study aimed to investigate this association and the mechanisms underlying TRPC1/6 signaling-mediated PAH.

Methods: Human pulmonary arterial smooth muscle cells (hPASMCs) were transfected with p65 overexpressing (pcDNA-p65) and interfering plasmids (shp65) and incubated in normal and hypoxic conditions (4% O₂ and 72 h). The effects of hypoxia and p65 expression on cell proliferation, invasion, apoptosis, [Ca²⁺]i, PPARγ, and TRPC1/6 expression were determined using Cell Counting Kit-8 (CCK-8), Transwell, Annexin V/PI, Fura-2/AM, and western blotting, respectively. In addition, the binding of p65 or PPARγ proteins to the TRPC6 promoter was validated using a dual-luciferase report assay, chromatin-immunoprecipitation-polymerase chain reaction (ChIP-PCR), and electrophoretic mobility shift assay (EMSA).

Results: Hypoxia inhibited hPASMC apoptosis and promoted cell proliferation and invasion. Furthermore, it increased [Ca²⁺]i and the expression of TRPC1/6, p65, and Bcl-2 proteins. Moreover, pcDNA-p65 had similar effects on hypoxia treatment by increasing TRPC1/6 expression, [Ca²⁺]i, hPASMC proliferation, and invasion. The dual-luciferase report and ChIP-PCR assays revealed three p65 binding sites and two PPARγ binding sites on the promoter region of TRPC6. In addition, hypoxia treatment and shPPARγ promoted the binding of p65 to the TRPC6 promoter, whereas shp65 promoted the binding of PPARγ to the TRPC6 promoter.

Conclusion: Competitive binding of NF-κB p65 and PPARγ to TRPC6 produced an anti-PAH effect.

Natural ingredients from Chinese materia medica for pulmonary hypertension

Pulmonary hypertension (PH) is a severe pathophysiological condition characterized by pulmonary artery remodeling and continuous increases in pulmonary artery pressure, which may eventually develop to right heart failure and death. Although newly discovered and incredible treatment strategies in recent years have improved the prognosis of PH, limited types of effective and economical drugs for PH still makes it as a life-threatening disease. Some drugs from Chinese materia medica (CMM) have been traditionally applied in the treatment of lung diseases. Accumulating evidence suggests active pharmaceutical ingredients (APIs) derived from those medicines brings promising future for the prevention and treatment of PH. In this review, we summarized the pharmacological effects of APIs derived from CMM which are potent in treating PH, so as to provide new thoughts for initial drug discovery and identification of potential therapeutic strategies in alternative medicine for PH.

The effects of iloprost and beta3 receptor agonist on TRPA1 and TRPC1 immunreactivity in an experimental lower extremty ischemia-reperfusion injury model

BACKGROUND

In this study, we aimed to investigate the effects of antioxidant iloprost (ILO) and ß3 adrenergic receptor agonist (BRL) on transient receptor potential ankyrin 1 (TRPA1) and transient receptor potential canonical 1 (TRPC1) ion channels on an experimental ischemia and reperfusion injury model in 30 male Wistar albino rats aged 8-10 weeks.

METHODS

Wistar Albino rats aged were divided into 5 equal groups. Group I Sham operation, Group II IR (ischemiareperfusion) procedure, Group III IR + intravenous ILO administration, Group IV IR + intraperitoneal BRL administration, and Group V IR + intravenous ILO + intraperitoneal BRL administration group. Two ng/kg/min ILO intravenous infusion was applied to the ILO group. A single dose of 5 mcg/kg BRL intraperitoneal was applied to BRL group. TOS (total oxidant status), TRPA1, and TRPC1 levels were measured with ELISA (enzyme linked immunosorbent assay) in serum, immunohistochemical staining in musculus quadriceps femoris tissue.

RESULTS

Compared with the sham group, the IR group had a statistically significant increase in serum levels of TOS (p = 0.004), TRPA1 (p = 0.002), and TRPC1 (p = 0.008) along with TRPA1- and TRPC1-immunoreactivity (p = 0.005, each) in the tissue. When compared with the IR group in terms of serum levels of TRPA1 and tissue TRPA1-immunoreactivity, although there was no statistically significant difference in the IR+Ilo (p = 0.257 and p = 0.429, respectively), IR+Brl (p = 0.024 and p = 0.177, respectively), and IR+Ilo+Brl (p = 0.024 and p = 0.329, respectively) groups, serum levels of TOS and TRPC1 along with tissue TRPC1-immunoreactivity were statistically significantly reduced in the IR+Ilo (p = 0.002, p = 0.008, and p = 0.004, respectively), IR+Brl (p = 0.004, p = 0.008, and p = 0.004, respectively), and IR+Ilo+Brl groups (p = 0.002, p = 0.008, and p = 0.004, respectively).

DISCUSSION

In IR group serum TOS, TRPA1 and TRPC1 levels ,and tissue TRPA1 and TRPC1 immunoreactivity were statistically significant increase when compared to the sham group. In IR+ILO, IR+BRL and IR+ILO+BRL groups serum TRPA1 and tissue TRPA1 immunoreactivity did not change when compared to IR group. Serum TOS and TRPC1 levels, tissue TRPC1 immunoreactivty were statistically significant decreased when compared to IR group. More detailed and expanded population studies are needed to discuss our results.

Mechanosensitivity in Pulmonary Circulation: Pathophysiological Relevance of Stretch-Activated Channels in Pulmonary Hypertension

A variety of cell types in pulmonary arteries (endothelial cells, fibroblasts, and smooth muscle cells) are continuously exposed to mechanical stimulations such as shear stress and pulsatile blood pressure, which are altered under conditions of pulmonary hypertension (PH). Most functions of such vascular cells (e.g., contraction, migration, proliferation, production of extracellular matrix proteins, etc.) depend on a key event, i.e., the increase in intracellular calcium concentration ([Ca²⁺]_i) which results from an influx of extracellular Ca²⁺ and/or a release of intracellular stored Ca²⁺. Calcium entry from the extracellular space is a major step in the elevation of [Ca²⁺]_i, involving a variety of plasmalemmal Ca²⁺ channels including the superfamily of stretch-activated channels (SAC). A common characteristic of SAC is that their gating depends on membrane stretch. In general, SAC are non-selective Ca²⁺-permeable cation channels, including proteins of the TRP (Transient Receptor Potential) and Piezo channel superfamily. As membrane mechano-transducers, SAC convert physical forces into biological signals and hence into a cell response. Consequently, SAC play a major role in pulmonary arterial calcium homeostasis and, thus, appear as potential novel drug targets for a better management of PH.

Sodium Tanshinone IIA Sulfonate Attenuates Tumor Oxidative Stress and Promotes Apoptosis in an Intermittent Hypoxia Mouse Model

Objective:

Intermittent hypoxia, a significant feature of obstructive sleep apnea, has pro-tumorigenic effects. Here, we investigated the effect of sodium tanshinone IIA sulfonate on oxidative stress and apoptosis in a mouse model of Lewis lung carcinoma with intermittent hypoxia.

Methods:

Mice were randomly assigned to normoxia (control), normoxia plus sodium tanshinone IIA sulfonate (control + sodium tanshinone IIA sulfonate), intermittent hypoxia, and intermittent hypoxia + sodium tanshinone IIA sulfonate groups. Intermittent hypoxia administration lasted 5 weeks in the intermittent hypoxia groups. Lewis lung carcinoma cells were injected into the right flank of each mouse after 1 week of intermittent hypoxia exposure. Sodium tanshinone IIA sulfonate was injected intraperitoneally in the control + sodium tanshinone IIA sulfonate and intermittent hypoxia + sodium tanshinone IIA sulfonate groups. Tumor oxidative stress was evaluated by detection of malondialdehyde and superoxide dismutase. The apoptosis of tumor cells was evaluated by the terminal deoxynucleotidyl transferase dUTP nick-end labeling assay as well as by Western blot analysis of B-cell lymphoma 2-associated X protein and cleaved caspase-3 expression. Additionally, the expression of hypoxia-induced factor-1α, nuclear factor erythroid 2-related factor 2, and nuclear factor kappa B was also evaluated by Western blot.

Results:

Compared with the control group, the intermittent hypoxia treatment significantly increased Lewis lung carcinoma tumor growth and oxidative stress (serum malondialdehyde) but decreased serum levels of SOD and pro-apoptotic markers (terminal deoxynucleotidyl transferase dUTP nick-end labeling staining, B-cell lymphoma 2-associated X protein, and cleaved caspase-3). These changes were significantly attenuated by intraperitoneal injection of sodium tanshinone IIA sulfonate. Lower nuclear factor erythroid 2-related factor 2 and higher nuclear factor kappa B levels in the intermittent hypoxia group were clearly reversed by sodium tanshinone IIA sulfonate treatment. In addition, sodium tanshinone IIA sulfonate administration decreased the high expression of hypoxia-induced factor-1α induced by intermittent hypoxia.

Conclusion:

Intermittent hypoxia treatment resulted in high oxidative stress and low apoptosis in Lewis lung carcinoma–implanted mice, which could be attenuated by sodium tanshinone IIA sulfonate administration possibly through a mechanism mediated by the nuclear factor erythroid 2-related factor 2/nuclear factor kappa B signaling pathway.

Targeted Drugs for Treatment of Pulmonary Arterial Hypertension: Past, Present, and Future Perspectives

Pulmonary arterial hypertension (PAH) is a devastating disease that can lead to right ventricular failure and premature death. Although approved drugs have been shown to be safe and effective, PAH remains a severe clinical condition, and the long-term survival of patients with PAH is still suboptimal. Thus, potential therapeutic targets and new agents to treat PAH are urgently needed. In recent years, a variety of related pathways and potential therapeutic targets have been found, which brings new hope for PAH therapy. In this perspective, not only are the marketed drugs used to treat PAH summarized but also the recently developed novel pharmaceutical therapies currently in clinical trials are discussed. Furthermore, the advances in natural products as potential treatment for PAH are also updated.

Mechanism Study of the Protective Effects of Sodium Tanshinone IIA Sulfonate Against Atorvastatin-Induced Cerebral Hemorrhage in Zebrafish: Transcriptome Analysis

Hemorrhage stroke is a severe vascular disease of the brain with a high mortality rate in humans. Salvia miltiorrhiza Bunge (Danshen) is a well-known Chinese Materia Medica for treating cerebral vascular and cardiovascular diseases in traditional Chinese medicine. Sodium tanshinone IIA sulfonate (STS) is a water-soluble derivative of tanshinone IIA, which is the main active ingredient of Danshen. In our previous study, we established a zebrafish model of cerebral hemorrhage and found that STS dramatically decreased both the hemorrhage rate and hemorrhage area, although the underlying mechanism was not fully elucidated. We conducted a transcriptome analysis of the protective effect of STS against atorvastatin (Ator)-induced cerebral hemorrhage in zebrafish using RNA-seq technology. RNA-seq revealed 207 DEGs between the Ator-treated group and control group; the expression levels of 53 DEGs between the Ator-treated group and control group were reversed between the STS + Ator-treated group and Ator-treated group. GO enrichment analysis indicated that these 53 DEGs encode proteins with roles in hemoglobin complexes, oxygen carrier activity and oxygen binding, etc. KEGG analysis suggested that these 53 DEGs were most enriched in three items, namely, porphyrin and chlorophyll metabolism, ferroptosis, and the HIF-1 signaling pathway. The PPI network analysis identified 12 hub genes, and we further verified that Ator elevated the mRNA expression levels of hemoglobin (hbae1.3, hbae3, hbae5, hbbe2, and hbbe3), carbonic anhydrase (cahz), HIF-1 (hif1al2) and Na+/H+ exchanger (slc4a1a and slc9a1) genes, while STS significantly suppressed these genes. In addition, we found that pharmacological inhibition of PI3K/Akt, MAPKs, and mTOR signaling pathways by specific inhibitors partially attenuated the protective effect of STS against Ator-induced cerebral hemorrhage in zebrafish, regardless of mTOR inhibition. We concluded that hemoglobin, carbonic anhydrase, Na+/H+ exchanger and HIF-1 genes might be potential biomarkers of Ator-induced cerebral hemorrhage in zebrafish, as well as pharmacological targets of STS. Moreover, HIF-1 and its regulators, i.e., the PI3K/Akt and MAPK signaling pathways, were involved in the protective effect of STS against Ator-induced cerebral hemorrhage. This study also provided evidence of biomarkers involved in hemorrhage stroke and improved understanding of the effects of HMG-COA reductase inhibition on vascular permeability and cerebral hemorrhage.

Carboxyl terminus of Hsc70-interacting protein (CHIP) promotes pulmonary artery smooth muscle cell (PASMC) proliferation via enhancement of intracellular Ca2+ concentration ([Ca2+]i)

AIMS OF THE STUDY

To investigate the effect of carboxyl terminus of Hsc70-interacting protein (CHIP) on pulmonary arterial smooth muscle cell (PASMC) proliferation and the underlying mechanism. Materials and Methods: PASMCs were harvested from distal PAs isolated from SD rat lungs and cultured. After CHIP overexpression, PASMCs were exposed to normoxia or hypoxia for 60 h. Then, PASMC proliferation, store-operated Ca²⁺ entry (SOCE), [Ca²⁺]_i and the expression of TRPC1, TRPC4, and TRPC6 in PASMCs were measured. Results: CHIP overexpression promoted PASMC proliferation, SOCE, [Ca²⁺]_i and the expression of TRPC1, TRPC4, and TRPC6. Conclusions: CHIP stimulates PASMC proliferation likely by targeting the TRPC1,4,6-SOCE-[Ca²⁺]_i signaling pathway.

Sodium Tanshinone II Sulfonate A Ameliorates Hypoxia-Induced Pulmonary Hypertension

Background

Pulmonary hypertension (PH) remains a prevalent disease globally. Sodium tanshinone II sulfonate A (STS) has been used in clinical treatment of PH.

Aims

The aim of the present study was to investigate the effect of sodium STS treatment on hypoxia-induced PH and related mechanisms.

Methods

Male Sprague-Dawley rats were housed in a hypoxic chamber with an oxygen concentration of 10 ± 1% for 8 h a day over 21 days. Rats were treated with either STS (low-dose: 10 mg/kg or high-dose: 30 mg/kg) or LY294002 (which is an inhibitor of PI3K). Pulmonary arterial pressure (PAP) was measured, right ventricular hypertrophy parameters were monitored, lung edema parameters were measured, and pathological changes were observed by hematoxylin-eosin (HE) staining. Protein expressions of apoptosis, and PI3K/AKT/mTOR/autophagy pathways in rat lung tissue were examined by western blot. Levels of the pro-inflammatory factors IL-6, IL-8, TNF-α in lung tissues of rats were measured using an enzyme linked immunosorbent assay (ELISA).

Results

Results of our study demonstrate that persistent exposure to hypoxic conditions increased PAP, right ventricular hypertrophy, lung edema, parameters of lung vascular proliferation and decreased the ratio of Bax/Bcl-2. Furthermore, hypoxic conditions activated the PI3K/Akt/mTOR pathway, inhibited autophagy, and elevated abundance of inflammatory factors in rat lung tissue. Treatment with STS resulted in a dose-dependent decrease in PAP, right ventricular hypertrophy, lung edema, lung vascular proliferation and reversed hypoxia induced lung tissue protein expression and pro-inflammatory factors in rat lung tissue. In addition, hypoxia-induced increases in PAP, cardiac hypertrophy, and lung expression of the proteins PI3K/Akt/mTOR/autophagy pathway were partially reversed by treatment with LY294002.

Conclusions

STS alleviates hypoxia-induced PH by promoting apoptosis, inhibiting PI3K/AKT/mTOR pathway, up-regulating autophagy, and inhibiting inflammatory responses.

Tetramethylpyrazine: A promising drug for the treatment of pulmonary hypertension

BACKGROUND AND PURPOSE

Tetramethylpyrazine (TMP) was originally isolated from the traditional Chinese herb ligusticum and the fermented Japanese food natto and has since been synthesized. TMP has a long history of beneficial effects in the treatment of many cardiovascular diseases. Here we have evaluated the therapeutic effects of TMP on pulmonary hypertension (PH) in animal models and in patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH).

EXPERIMENTAL APPROACH

Three well-defined models of PH -chronic hypoxia (10% O₂ )-induced PH (HPH), monocrotaline-induced PH (MCT-PH) and Sugen 5416/hypoxia-induced PH (SuHx-PH) - were used in Sprague-Dawley rats, and assessed by echocardiography, along with haemodynamic and histological techniques. Primary cultures of rat distal pulmonary arterial smooth muscle cells (PASMCs) were used to study intracellular calcium levels. Western blots and RT-qPCR assays were also used. In the clinical cohort, patients with PAH or CTEPH were recruited. The effects of TMP were evaluated in all systems.

KEY RESULTS

TMP (100 mg·kg^-1 ·day^-1 ) prevented rats from developing experimental PH and ameliorated three models of established PH: HPH, MCT-PH and SuHx-PH. The therapeutic effects of TMP were accompanied by inhibition of intracellular calcium homeostasis in PASMCs. In a small cohort of patients with PAH or CTEPH, oral administration of TMP (100 mg, t.i.d. for 16 weeks) increased the 6-min walk distance and improved the 1-min heart rate recovery.

CONCLUSION AND IMPLICATIONS

Our results suggest that TMP is a novel and inexpensive medication for treatment of PH. Clinical trial is registered with www.chictr.org.cn (ChiCTR-IPR-14005379).

TRPC channels: Structure, function, regulation and recent advances in small molecular probes

Transient receptor potential canonical (TRPC) channels constitute a group of receptor-operated calcium-permeable nonselective cation channels of the TRP superfamily. The seven mammalian TRPC members, which can be further divided into four subgroups (TRPC1, TRPC2, TRPC4/5, and TRPC3/6/7) based on their amino acid sequences and functional similarities, contribute to a broad spectrum of cellular functions and physiological roles. Studies have revealed complexity of their regulation involving several components of the phospholipase C pathway, G_i and G_o proteins, and internal Ca²⁺ stores. Recent advances in cryogenic electron microscopy have provided several high-resolution structures of TRPC channels. Growing evidence demonstrates the involvement of TRPC channels in diseases, particularly the link between genetic mutations of TRPC6 and familial focal segmental glomerulosclerosis. Because TRPCs were discovered by the molecular identity first, their pharmacology had lagged behind. This is rapidly changing in recent years owning to great efforts from both academia and industry. A number of potent tool compounds from both synthetic and natural products that selective target different subtypes of TRPC channels have been discovered, including some preclinical drug candidates. This review will cover recent advancements in the understanding of TRPC channel regulation, structure, and discovery of novel TRPC small molecular probes over the past few years, with the goal of facilitating drug discovery for the study of TRPCs and therapeutic development.

Structural and functional definition of the pulmonary vein system in a chronic hypoxia-induced pulmonary hypertension rat model

Unlike the pulmonary artery (PA), the pathophysiological changes of the pulmonary vein (PV) in the development of pulmonary hypertension (PH) remain largely unknown. In this study, we comprehensively investigated the structural and functional changes in the PV isolated from the chronic hypoxia (CH; 10% O₂, 21 days)-induced PH rat model (CHPH). Results showed that CH caused an increase in right ventricular pressure but did not affect the mean pulmonary venous pressure and the left atrial pressure. Similar to the PA, vascular lumen stenosis and medial thickening were also observed in the intrapulmonary veins isolated from the CHPH rats. Notably, CH induced more severe loss in the endothelium of intrapulmonary veins than the arteries. Then, the contractile response to 5-HT and U46619 was significantly greater in the intrapulmonary small veins (ISPV) and arteries (ISPA) isolated from CHPH rats than those from normoxic rats but not in the extrapulmonary and intrapulmonary large veins. Treatment with nifedipine (Nif), SKF96365 (SKF), or ryanodine and caffeine either partially attenuated (Nif) or dramatically abolished (SKF or ryanodine and caffeine) 5-HT-induced maximal contraction in ISPV from both normoxic and CHPH rats. Because of the severe loss of endothelium in the PV of CHPH rats, the decrease in acetylcholine (ACh)-induced endothelium-dependent relaxation was significantly larger in ISPV than ISPA, whereas the sodium nitroprusside-induced endothelium-independent relaxation was not altered in both ISPA and ISPV. In conclusion, our results provide fundamental data to comprehensively define the PV system in CHPH rat model.

Sodium tanshinone IIA sulfonate: A review of pharmacological activity and pharmacokinetics

Sodium tanshinone IIA sulfonate (STS) is a water-soluble derivate of tanshinone IIA (Tan IIA) which is an active lipophilic constitute of Chinese Materia Medica Salvia miltiorrhiza Bge. (Danshen). STS presents multiple pharmacological activities, including anti-oxidant, anti-inflammation and anti-apoptosis, and has been approved for treatment of cardiovascular diseases by China State Food and Drug Administration (CFDA). In this review, we comprehensively summarized the pharmacological activities and pharmacokinetics of STS, which could support the further application and development of STS. In the recent decades, numerous experimental and clinical studies have been conducted to investigate the potential treatment effects of STS in various diseases, such as heart diseases, brain diseases, pulmonary diseases, cancers, sepsis and so on. The underlying mechanisms were most related to anti-oxidative and anti-inflammatory effects of STS via regulating various transcription factors, such as NF-κB, Nrf2, Stat1/3, Smad2/3, Hif-1α and β-catenin. Iron channels, including Ca²⁺, K⁺ and Cl^- channels, were also the important targets of STS. Additionally, we emphasized the differences between STS and Tan IIA despite the interchangeable use of Tan IIA and STS in many previous studies. It is promising to improve the efficacy and reduce side effects of chemotherapeutic drug by the combination use of STS in canner treatment. The application of STS in pregnancy needs to be seriously considered. Moreover, the drug-drug interactions between STS and other drugs needs to be further studied as well as the complications of STS.

Salvia miltiorrhiza in Treating Cardiovascular Diseases: A Review on Its Pharmacological and Clinical Applications

Bioactive chemical constitutes from the root of Salvia miltiorrhiza classified in two major groups, viz., liposoluble tanshinones and water-soluble phenolics. Tanshinone IIA is a major lipid-soluble compound having promising health benefits. The in vivo and in vitro studies showed that the tanshinone IIA and salvianolate have a wide range of cardiovascular and other pharmacological effects, including antioxidative, anti-inflammatory, endothelial protective, myocardial protective, anticoagulation, vasodilation, and anti-atherosclerosis, as well as significantly help to reduce proliferation and migration of vascular smooth muscle cells. In addition, some of the clinical studies reported that the S. miltiorrhiza preparations in combination with Western medicine were more effective for treatment of various cardiovascular diseases including angina pectoris, myocardial infarction, hypertension, hyperlipidemia, and pulmonary heart diseases. In this review, we demonstrated the potential applications of S. miltiorrhiza, including pharmacological effects of salvianolate, tanshinone IIA, and its water-soluble derivative, like sodium tanshinone IIA sulfonate. Moreover, we also provided details about the clinical applications of S. miltiorrhiza preparations in controlling the cardiovascular diseases.

Natural plant products in treatment of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a severe disease characterized by progressive remodeling of distal pulmonary arteries and persistent elevation of pulmonary vascular resistance (PVR), which leads to right ventricular dysfunction, heart failure, and eventually death. Although treatment responsiveness for this disease is improving, it continues to be a life-threatening condition. With the clinical efficacy of natural plant products being fully confirmed by years of practice, more and more recognition and attention have been obtained from the international pharmaceutical industry. Moreover, studies over the past decades have demonstrated that drugs derived from natural plants show unique advantages and broad application prospects in PAH treatment, not to mention the historical application of Chinese traditional medicine in cardiopulmonary diseases. In this review, we focus on summarizing natural plant compounds with therapeutic properties in PAH, according to the extracts, fractions, and pure compounds from plants into categories, hoping it to be helpful for basic research and clinical application.

Salvia miltiorrhiza: A Potential Red Light to the Development of Cardiovascular Diseases

Salvia miltiorrhiza Bunge, also known as Danshen in Chinese, has been widely used to treat cardiovascular diseases (CVD) in China and other Asia countries. Here, we summarize literatures of the historical traditional Chinese medicine (TCM) interpretation of the action of Salvia miltiorrhiza, its use in current clinical trials, its main phytochemical constituents and its pharmacological findings by consulting Pubmed, China Knowledge Resource Integrated, China Science and Technology Journal, and the Web of Science Databases. Since 2000, 39 clinical trials have been identified that used S. miltiorrhiza in TCM prescriptions alone or with other herbs for the treatment of patients with CVD. More than 200 individual compounds have been isolated and characterized from S. miltiorrhiza, which exhibited various pharmacological activities targeting different pathways for the treatment of CVD in various animal and cell models. The isolated compounds may provide new perspectives in alternative treatment regimes and reveal novel chemical scaffolds for the development of anti-CVD drugs. Meanwhile, there are also some rising concerns of the potential side effects and drug-drug interactions of this plant. The insights gained from this study will help us to better understanding of the actions of this herb for management of cardiovascular disorders. As an herb of red root, S. miltiorrhiza will act as a potential red light to prevent the development of CVD.

A study on blocking store-operated Ca2+ entry in pulmonary arterial smooth muscle cells with xyloketals from marine fungi

In this study, the effect of four xyloketals 1-4 on store-operated calcium entry (SOCE) was investigated in primary distal pulmonary arterial smooth muscle cells (PASMCs) isolated from mice. The results showed that xyloketal A (1), an unusual ketal with C-3 symmetry, exhibited strong SOCE blocking activity. Secretion of interleukin-8 (IL-8) was also inhibited by xyloketal A. The parallel artificial membrane permeability assay (PAMPA) of 1-4 suggested that these xyloketals penetrated easily through the cell membrane. Moreover, the molecular docking study of xyloketal A with activation region of the stromal interaction molecule (STIM) 1 and the calcium release-activated calcium modulator (ORAI) 1 (STIM1-ORAI1) protein complex, the key domain of SOCE, revealed that xyloketal A exhibited a noncovalent interaction with the key residue lysine 363 (LYS363) in the identified cytosolic regions in STIM1-C. These findings provided useful information about xyloketal A as a SOCE inhibitor for further evaluation.

Canonical Transient Receptor Potential Channels and Their Link with Cardio/Cerebro-Vascular Diseases

The canonical transient receptor potential channels (TRPCs) constitute a series of nonselective cation channels with variable degrees of Ca²⁺ selectivity. TRPCs consist of seven mammalian members, TRPC1, TRPC2, TRPC3, TRPC4, TRPC5, TRPC6, and TRPC7, which are further divided into four subtypes, TRPC1, TRPC2, TRPC4/5, and TRPC3/6/7. These channels take charge of various essential cell functions such as contraction, relaxation, proliferation, and dysfunction. This review, organized into seven main sections, will provide an overview of current knowledge about the underlying pathogenesis of TRPCs in cardio/cerebrovascular diseases, including hypertension, pulmonary arterial hypertension, cardiac hypertrophy, atherosclerosis, arrhythmia, and cerebrovascular ischemia reperfusion injury. Collectively, TRPCs could become a group of drug targets with important physiological functions for the therapy of human cardio/cerebro-vascular diseases.

The Role of Transient Receptor Potential Channel 6 Channels in the Pulmonary Vasculature

Canonical or classical transient receptor potential channel 6 (TRPC6) is a Ca²⁺-permeable non-selective cation channel that is widely expressed in the heart, lung, and vascular tissues. The use of TRPC6-deficient (“knockout”) mice has provided important insights into the role of TRPC6 in normal physiology and disease states of the pulmonary vasculature. Evidence indicates that TRPC6 is a key regulator of acute hypoxic pulmonary vasoconstriction. Moreover, several studies implicated TRPC6 in the pathogenesis of pulmonary hypertension. Furthermore, a unique genetic variation in the TRPC6 gene promoter has been identified, which might link the inflammatory response to the upregulation of TRPC6 expression and ultimate development of pulmonary vascular abnormalities in idiopathic pulmonary arterial hypertension. Additionally, TRPC6 is critically involved in the regulation of pulmonary vascular permeability and lung edema formation during endotoxin or ischemia/reperfusion-induced acute lung injury. In this review, we will summarize latest findings on the role of TRPC6 in the pulmonary vasculature.

Atheroprotective Effects and Molecular Targets of Tanshinones Derived From Herbal Medicine Danshen

Medicinal plant-derived bioactive compounds modulate multiple therapeutic targets in cardiovascular diseases (CVDs), rendering herb-derived phytochemicals effective against one of the major CVDs-atherosclerosis. Danshen (Salvia milthiorriza Bunge) is a Chinese medicine that has been used in cardio- and cerebro-vascular therapeutic remedies in Asian countries for many years. Emerging evidence from cellular, animal, and clinical studies suggests that major lipophilic tanshinones from Danshen can treat atherosclerotic CVDs. In this review, we highlight recent advances in understanding the molecular mechanisms of tanshinones in treating atherosclerosis, ranging from endothelial dysfunction to chronic inflammation. We also overview new molecular targets of tanshinones, including endothelial nitric oxide synthase, AMP-activated protein kinase, ABC transporter A1, heme oxygenase 1, soluble epoxide hydrolase, 11β-hydroxysteroid dehydrogenase, estrogen receptor, and proprotein convertase subtilisin/kexin type 9. Thus, this review provides a new perspective for advancing our understanding of the "ancient" herb Danshen from "modern" biomedical perspectives, supporting the possibility of exploiting tanshinones and derivatives as effective therapeutics against atherosclerosis-related cardiovascular and metabolic diseases.

Tanshinone IIA suppresses gastric cancer cell proliferation and migration by downregulation of FOXM1

Tanshinone IIA (TSN) exhibits a variety of anticancer effects. However, whether it inhibits gastric cancer (GC) cell proliferation and migration and the mechanism remain unclear. In the present study, different concentrations of TSN were co-incubated with SGC-7901 cells. The pcDNA-FOXM1 or FOXM1-siRNA plasmid was transfected into cells before treatment with 5 µg/l TSN. The proliferation and migration abilities of the SGC-7901 cells were tested by MTT and wound healing assays. Western blotting was used to investigate the expression levels of P21, Ki-67, PCNA, MMP-2, MMP-9 and FOXM1. We found that compared with the control, the proliferation and migration abilities of the SGC-7901 cells were decreased after incubation with different concentrations of TSN in a dose-dependent manner (p<0.01). Moreover, the expression levels of Ki-67, PCAN, MMP-2, MMP-9 and FOXM1 were decreased, and P21 was increased in the TSN-treated SGC-7901 cells (p<0.01). In addition, downregulation of FOXM1 by FOXM1-siRNA had the same effect as TSN on SGC-7901 cells, and overexpression of FOXM1 partly abrogated TSN-mediated inhibition of SGC-7901 cell proliferation and migration. These results suggested that TSN inhibits SGC-7901 cell proliferation and migration by downregulation of FOXM1.

Sodium tanshinone IIA sulfonate inhibits hypoxia-induced enhancement of SOCE in pulmonary arterial smooth muscle cells via the PKG-PPAR-γ signaling axis

Our laboratory previously showed that sodium tanshinone IIA sulfonate (STS) inhibited store-operated Ca(2+) entry (SOCE) through store-operated Ca(2+) channels (SOCC) via downregulating the expression of transient receptor potential canonical proteins (TRPC), which contribute to the formation of SOCC (Wang J, Jiang Q, Wan L, Yang K, Zhang Y, Chen Y, Wang E, Lai N, Zhao L, Jiang H, Sun Y, Zhong N, Ran P, Lu W. Am J Respir Cell Mol Biol 48: 125-134, 2013). The detailed molecular mechanisms by which STS inhibits SOCE and downregulates TRPC, however, remain largely unknown. We have previously shown that, under hypoxic conditions, inhibition of protein kinase G (PKG) and peroxisome proliferator-activated receptor-γ (PPAR-γ) signaling axis results in the upregulation of TRPC (Wang J, Yang K, Xu L, Zhang Y, Lai N, Jiang H, Zhang Y, Zhong N, Ran P, Lu W. Am J Respir Cell Mol Biol 49: 231-240, 2013). This suggests that strategies targeting the restoration of this signaling pathway may be an effective treatment strategy for pulmonary hypertension. In this study, our results demonstrated that STS treatment can effectively prevent the hypoxia-mediated inhibition of the PKG-PPAR-γ signaling axis in rat distal pulmonary arterial smooth muscle cells (PASMCs) and distal pulmonary arteries. These effects of STS treatment were blocked by pharmacological inhibition or specific small interfering RNA knockdown of either PKG or PPAR-γ. Moreover, targeted PPAR-γ agonist markedly enhanced the beneficial effects of STS. These results comprehensively suggest that STS treatment can prevent hypoxia-mediated increases in intracellular calcium homeostasis and cell proliferation, by targeting and restoring the hypoxia-inhibited PKG-PPAR-γ signaling pathway in PASMCs.

Peroxisome Proliferator-Activated Receptor γ-Mediated Inhibition on Hypoxia-Triggered Store-Operated Calcium Entry. A Caveolin-1-Dependent Mechanism

Our previous publication demonstrated that peroxisome proliferator-activated receptor γ (PPARγ) inhibits the pathogenesis of chronic hypoxia (CH)-induced pulmonary hypertension by targeting store-operated calcium entry (SOCE) in rat distal pulmonary arterial smooth muscle cells (PASMCs). In this study, we aim to determine the role of a membrane scaffolding protein, caveolin-1, during the suppressive process of PPARγ on SOCE. Adult (6-8 weeks) male Wistar rats (200-250 g) were exposed to CH (10% O2) for 21 days to establish CH-induced pulmonary hypertension. Primary cultured rat distal PASMCs were applied for the molecular biological experiments. First, hypoxic exposure led to 2.5-fold and 1-fold increases of caveolin-1 protein expression in the distal pulmonary arteries and PASMCs, respectively. Second, effective knockdown of caveolin-1 significantly reduced hypoxia-induced SOCE for 58.2% and 41.5%, measured by Mn(2+) quenching and extracellular Ca(2+) restoration experiments, respectively. These results suggested that caveolin-1 acts as a crucial regulator of SOCE, and hypoxia-up-regulated caveolin-1 largely accounts for hypoxia-elevated SOCE in PASMCs. Then, by using a high-potency PPARγ agonist, GW1929, we detected that PPARγ activation inhibited SOCE and caveolin-1 protein for 62.5% and 59.8% under hypoxia, respectively, suggesting that caveolin-1 also acts as a key target during the suppressive process of PPARγ on SOCE in PASMCs. Moreover, by using effective small interfering RNAs against PPARγ and caveolin-1, and PPARγ antagonist, T0070907, we observed that PPARγ plays an inhibitory role on caveolin-1 protein by promoting its lysosomal degradation, without affecting the messenger RNA level. PPARγ inhibits SOCE, at least partially, by suppressing cellular caveolin-1 protein in PASMCs.

Hypoxic pulmonary hypertension in chronic lung diseases: novel vasoconstrictor pathways

Pulmonary hypertension is a well recognised complication of chronic hypoxic lung diseases, which are among the most common causes of death and disability worldwide. Development of pulmonary hypertension independently predicts reduced life expectancy. In chronic obstructive pulmonary disease, long-term oxygen therapy ameliorates pulmonary hypertension and greatly improves survival, although the correction of alveolar hypoxia and pulmonary hypertension is only partial. Advances in understanding of the regulation of vascular smooth muscle tone show that chronic vasoconstriction plays a more important part in the pathogenesis of hypoxic pulmonary hypertension than previously thought, and that structural vascular changes contribute less. Trials of existing vasodilators show that pulmonary hypertension can be ameliorated and systemic oxygen delivery improved in carefully selected patients, although systemic hypotensive effects limit the doses used. Vasoconstrictor pathways that are selective for the pulmonary circulation can be blocked to reduce hypoxic pulmonary hypertension without causing systemic hypotension, and thus provide potential targets for novel therapeutic strategies.

Chinese Herbal Medicine Treatment Improves the Overall Survival Rate of Individuals with Hypertension among Type 2 Diabetes Patients and Modulates In Vitro Smooth Muscle Cell Contractility

Type 2 diabetes (T2D) is a chronic, multifactorial, and metabolic disorder accounting for 90% diabetes cases worldwide. Among them, almost half of T2D have hypertension, which is responsible for cardiovascular disease, morbidity, and mortality in these patients. The Chinese herbal medicine (CHM) prescription patterns of hypertension individuals among T2D patients have yet to be characterized. This study, therefore, aimed to determine their prescription patterns and evaluate the CHM effect. A cohort of one million randomly sampled cases from the National Health Insurance Research Database (NHIRD) was used to investigate the overall survival rate of CHM users, and prescription patterns. After matching CHM and non-CHM users for age, gender and date of diagnosis of hypertension, 980 subjects for each group were selected. The CHM users were characterized with slightly longer duration time from diabetes to hypertension, and more cases for hyperlipidaemia. The cumulative survival probabilities were higher in CHM users than in non-CHM users. Among these top 12 herbs, Liu-Wei-Di-Huang-Wan, Jia-Wei-Xiao-Yao-San, Dan-Shen, and Ge-Gen were the most common herbs and inhibited in vitro smooth muscle cell contractility. Our study also provides a CHM comprehensive list that may be useful in future investigation of the safety and efficacy for individuals with hypertension among type 2 diabetes patients.

Serum-glucocorticoid regulated kinase 1 regulates macrophage recruitment and activation contributing to monocrotaline-induced pulmonary arterial hypertension

Sustained inflammation is associated with pulmonary vascular remodeling and arterial hypertension (PAH). Serum-glucocorticoid regulated kinase 1 (SGK1) has been shown to participate in vascular remodeling, but its role in inflammation-associated PAH remains unknown. In this study, the importance of SGK1 expression and activation was investigated on monocrotaline (MCT)-induced PAH, an inflammation-associated experimental model of PAH used in mice and rats. The expression of SGK1 in the lungs of rats with MCT-induced PAH was significantly increased. Furthermore, SGK1 knockout mice were resistant to MCT-induced PAH and showed less elevation of right ventricular systolic pressure and right ventricular hypertrophy and showed reduced pulmonary vascular remodeling in response to MCT injection. Administering the SGK1 inhibitor, EMD638683, to rats also prevented the development of MCT-induced PAH. The expression of SGK1 was shown to take place primarily in alveolar macrophages. EMD638683 treatment suppressed macrophage infiltration and inhibited the proliferation of pulmonary arterial smooth muscle cells (PASMCs) in the lungs of rats with MCT-induced PAH. Co-culture of bone marrow-derived macrophages (BMDMs) from wild-type (WT) mice promoted proliferation of PASMC in vitro, whereas BMDMs from either SGK1 knockout mice or WT mice with EMD638683 treatment failed to induce this response. Collectively, the present results demonstrated that SGK1 is important to the regulation of macrophage activation that contributes to the development of PAH; thus, SGK1 may be a potential therapeutic target for the treatment of PAH.

Chronic hypoxia increases TRPC6 expression and basal intracellular Ca2+ concentration in rat distal pulmonary venous smooth muscle

BACKGROUND

Hypoxia causes remodeling and contractile responses in both pulmonary artery (PA) and pulmonary vein (PV). Here we explore the effect of hypoxia on PV and pulmonary venous smooth muscle cells (PVSMCs).

METHODS

Chronic hypoxic pulmonary hypertension (CHPH) model was established by exposing rats to 10% O2 for 21 days. Rat distal PVSMCs were isolated and cultured for in vitro experiments. The fura-2 based fluorescence calcium imaging was used to measure the basal intracellular Ca2+ concentration ([Ca2+]i) and store-operated Ca2+ entry (SOCE). Quantitative RT-PCR and western blotting were performed to measure the expression of mRNA and levels of canonical transient receptor potential (TRPC) protein respectively.

RESULTS

Hypoxia increased the basal [Ca2+]i and SOCE in both freshly dissociated and serum cultured distal PVSMCs. Moreover, hypoxia increased TRPC6 expression at mRNA and protein levels in both cultured PVSMCs exposed to prolonged hypoxia (4% O2, 60 h) and distal PV isolated from CHPH rats. Hypoxia also enhanced proliferation and migration of rat distal PVSMCs.

CONCLUSIONS

Hypoxia induces elevation of SOCE in distal PVSMCs, leading to enhancement of basal [Ca2+]i in PVSMCs. This enhancement is potentially correlated with the increased expression of TRPC6. Hypoxia triggered intracellular calcium contributes to promoted proliferation and migration of PVSMCs.

Blocking macrophage leukotriene b4 prevents endothelial injury and reverses pulmonary hypertension

Pulmonary hypertension (PH) is a serious condition that affects mainly young and middle-aged women, and its etiology is poorly understood. A prominent pathological feature of PH is accumulation of macrophages near the arterioles of the lung. In both clinical tissue and the SU5416 (SU)/athymic rat model of severe PH, we found that the accumulated macrophages expressed high levels of leukotriene A4 hydrolase (LTA4H), the biosynthetic enzyme for leukotriene B4 (LTB4). Moreover, macrophage-derived LTB4 directly induced apoptosis in pulmonary artery endothelial cells (PAECs). Further, LTB4 induced proliferation and hypertrophy of human pulmonary artery smooth muscle cells. We found that LTB4 acted through its receptor, BLT1, to induce PAEC apoptosis by inhibiting the protective endothelial sphingosine kinase 1 (Sphk1)-endothelial nitric oxide synthase (eNOS) pathway. Blocking LTA4H decreased in vivo LTB4 levels, prevented PAEC apoptosis, restored Sphk1-eNOS signaling, and reversed fulminant PH in the SU/athymic rat model of PH. Antagonizing BLT1 similarly reversed established PH. Inhibition of LTB4 biosynthesis or signal transduction in SU-treated athymic rats with established disease also improved cardiac function and reopened obstructed arterioles; this approach was also effective in the monocrotaline model of severe PH. Human plexiform lesions, one hallmark of PH, showed increased numbers of macrophages, which expressed LTA4H, and patients with connective tissue disease-associated pulmonary arterial hypertension exhibited significantly higher LTB4 concentrations in the systemic circulation than did healthy subjects. These results uncover a possible role for macrophage-derived LTB4 in PH pathogenesis and identify a pathway that may be amenable to therapeutic targeting.

Classical transient receptor potential 1 and 6 contribute to hypoxic pulmonary hypertension through differential regulation of pulmonary vascular functions

Hypoxic pulmonary hypertension is characterized by increased vascular tone, altered vasoreactivity, and vascular remodeling, which are associated with alterations in Ca(2+) homeostasis in pulmonary arterial smooth muscle cells. We have previously shown that classical transient receptor potential 1 and 6 (TRPC1 and TRPC6) are upregulated in pulmonary arteries (PAs) of chronic hypoxic rats, but it is unclear whether these channels are essential for the development of pulmonary hypertension. Here we found that pulmonary hypertension was suppressed in TRPC1 and TRPC6 knockout (Trpc1(-/-) and Trpc6(-/-)) mice compared with wild-type after exposure to 10% O(2) for 1 and 3 weeks. Muscularization of pulmonary microvessels was inhibited, but rarefaction was unaltered in hypoxic Trpc1(-/-) and Trpc6(-/-) mice. Small PAs of normoxic wild-type mice exhibited vasomotor tone, which was significantly enhanced by chronic hypoxia. Similar vasomotor tone was found in normoxic Trpc1(-/-) PAs, but the hypoxia-induced enhancement was blunted. In contrast, there was minimal vascular tone in normoxic Trpc6(-/-) PAs, but the hypoxia-enhanced tone was preserved. Chronic hypoxia caused significant increase in serotonin-induced vasoconstriction; the augmented vasoreactivity was attenuated in Trpc1(-/-) and eliminated in Trpc6(-/-) PAs. Moreover, the effects of 3-week hypoxia on pulmonary arterial pressure, right ventricular hypertrophy, and muscularization of microvessels were further suppressed in TRPC1-TRPC6 double-knockout mice. Our results, therefore, provide clear evidence that TRPC1 and TRPC6 participate differentially in various pathophysiological processes, and that the presence of TRPC1 and TRPC6 is essential for the full development of hypoxic pulmonary hypertension in the mouse model.

Sildenafil inhibits hypoxia-induced transient receptor potential canonical protein expression in pulmonary arterial smooth muscle via cGMP-PKG-PPARγ axis

Transient receptor potential canonical (TRPC) proteins play important roles in chronically hypoxic pulmonary hypertension (CHPH). Previous results indicated that sildenafil inhibited TRPC1 and TRPC6 expression in rat distal pulmonary arteries (PAs). However, the underlying mechanisms remain unknown. We undertook this study to investigate the downstream signaling of sildenafil's regulation on TRPC1 and TRPC6 expression in pulmonary arterial smooth muscle cells (PASMCs). Hypoxia-exposed rats (10% O2 for 21 d) and rat distal PASMCs (4% O2 for 60 h) were taken as models to mimic CHPH. Real-time PCR, Western blotting, and Fura-2-based fluorescent microscopy were performed for mRNA, protein, and Ca(2+) measurements, respectively. The cellular cyclic guanosine monophosphate (cGMP) analogue 8-(4-chlorophenylthio)-guanosine 3',5'-cyclic monophosphate sodium salt (CPT-cGMP) (100 μM) inhibited TRPC1 and TRPC6 expression, store-operated Ca(2+) entry (SOCE), and the proliferation and migration of PASMCs exposed to prolonged hypoxia. The inhibition of CPT-cGMP on TRPC1 and TRPC6 expression in PASMCs was relieved by either the inhibition or knockdown of cGMP-dependent protein kinase (PKG) and peroxisome proliferator-activated receptor γ (PPARγ) expression. Under hypoxic conditions, CPT-cGMP increased PPARγ expression. This increase was abolished by the PKG antagonists Rp8 or KT5823. PPARγ agonist GW1929 significantly decreased TRPC1 and TRPC6 expression in PASMCs. Moreover, hypoxia exposure decreased, whereas sildenafil treatment increased, PKG and PPARγ expression in PASMCs ex vivo, and in rat distal PAs in vivo. The suppressive effects of sildenafil on TRPC1 and TRPC6 in rat distal PAs and on the hemodynamic parameters of CHPH were inhibited by treatment with the PPARγ antagonist T0070907. We conclude that sildenafil inhibits TRPC1 and TRPC6 expression in PASMCs via cGMP-PKG-PPARγ-dependent signaling during CHPH.

Proteomic analysis reveals that proteasome subunit beta 6 is involved in hypoxia-induced pulmonary vascular remodeling in rats

Background

Chronic hypoxia (CH) is known to be one of the major causes of pulmonary hypertension (PH), which is characterized by sustained elevation of pulmonary vascular resistance resulting from vascular remodeling. In this study, we investigated whether the ubiquitin proteasome system (UPS) was involved in the mechanism of hypoxia-induced pulmonary vascular remodeling. We isolated the distal pulmonary artery (PA) from a previously defined chronic hypoxic pulmonary hypertension (CHPH) rat model, performed proteomic analyses in search of differentially expressed proteins belonging to the UPS, and subsequently identified their roles in arterial remodeling.

Results

Twenty-two proteins were differently expressed between the CH and normoxic group. Among them, the expression of proteasome subunit beta (PSMB) 1 and PSMB6 increased after CH exposure. Given that PSMB1 is a well-known structural subunit and PSMB6 is a functional subunit, we sought to assess whether PSMB6 could be related to the multiple functional changes during the CHPH process. We confirmed the proteomic results by real-time PCR and Western blot. With the increase in quantity of the active subunit, proteasome activity in both cultured pulmonary artery smooth muscle cells (PASMCs) and isolated PA from the hypoxic group increased. An MTT assay revealed that the proteasome inhibitor MG132 was able to attenuate the hypoxia-induced proliferation of PASMC in a dose-dependent manner. Knockdown of PSMB6 using siRNA also prevented hypoxia-induced proliferation.

Conclusion

The present study revealed the association between increased PSMB6 and CHPH. CH up-regulated proteasome activity and the proliferation of PASMCs, which may have been related to increased PSMB6 expression and the subsequently enhanced functional catalytic sites of the proteasome. These results suggested an essential role of the proteasome during CHPH development, a novel finding requiring further study.

Promising therapeutic effects of sodium tanshinone IIA sulfonate towards pulmonary arterial hypertension in patients

BACKGROUND

Pulmonary hypertension (PH) is a lethal disease with no cure currently available. Sodium Tanshinone IIA sulfonate (STS) is a water-soluble derivative of tanshinone IIA isolated as the major active component from salvia miltiorrhiza, a kind of Chinese herbal medicine. We investigate the efficacy of STS towards treatment of PH patients.

METHODS AND RESULTS

Five hospitalized patients were randomly enrolled for this study. These patients were suffering from various types of serious PH without getting sufficient benefits from sildenafil treatment (20 mg tid) for at least three months. The efficacy of STS on PH was evaluated by measuring the pulmonary arterial systolic pressure (PASP), RV size by echocardiography, 6-minute walking distance (6MWD), Borg dyspnea score, and WHO functional class of PH. Patients aged from 17 to 46 (average 33±11) years old, pulmonary arterial systolic pressure (PASP) ranged from 60 to 140 mmHg, RV size ranged from 25 to 39 mm were included in study. At the endpoint of observation for 8 weeks of STS infusion, they obtained reduction of PASP in the range of 14-45 (average 28.6±12.5) mmHg, RV size in the range of 0-10 (average 4.2±1.6). All patients exhibited improved exercise capacity with an increase of 6MWD from 63 to 268 (average 138.4±40.7) meters, significantly reduced Borg dyspnea score from maximum 9 down to 1 or 0, and reduced WHO functional class of PH from III or IV down to II.

CONCLUSIONS

These results indicate that STS exhibits remarkable beneficiary effects on treating PH patients either alone or in concert with sildenafil.

Bone morphogenetic protein 2 decreases TRPC expression, store-operated Ca(2+) entry, and basal [Ca(2+)]i in rat distal pulmonary arterial smooth muscle cells

Recent studies indicate that multiple bone morphogenetic protein (BMP) family ligands and receptors are involved in the development of pulmonary arterial hypertension, yet the underlying mechanisms are incompletely understood. Although BMP2 and BMP4 share high homology in amino acid sequence, they appear to exert divergent effects on chronic hypoxic pulmonary hypertension (CHPH). While BMP4 promotes vascular remodeling, BMP2 prevents CHPH. We previously demonstrated that BMP4 upregulates the expression of canonical transient receptor potential channel (TRPC) proteins and, thereby, enhances store-operated Ca(2+) entry (SOCE) and elevates intracellular Ca(2+) concentration ([Ca(2+)]i) in pulmonary arterial smooth muscle cells (PASMCs). In this study, we investigated the effects of BMP2 on these variables in rat distal PASMCs. We found that treatment with BMP2 (50 ng/ml, 60 h) inhibited TRPC1, TRPC4, and TRPC6 mRNA and protein expression. Moreover, BMP2 treatment led to reduced SOCE and decreased basal [Ca(2+)]i in PASMCs. These alterations were associated with decreased PASMC proliferation and migration. Conversely, knockdown of BMP2 with specific small interference RNA resulted in increased cellular levels of TRPC1, TRPC4, and TRPC6 mRNA and protein, enhanced SOCE, elevated basal [Ca(2+)]i, and increased proliferation and migration of PASMCs. Together, these results indicate that BMP2 participates in regulating Ca(2+) signaling in PASMCs by inhibiting TRPC1, TRPC4, and TRPC6 expression, thus leading to reduced SOCE and basal [Ca(2+)]i and inhibition of cell proliferation and migration.