Baicalin inhibits PDGF-BB-stimulated vascular smooth muscle cell proliferation through suppressing PDGFRβ-ERK signaling and increase in p27 accumulation and prevents injury-induced neointimal hyperplasia

Pharmacological mechanisms by which baicalin ameliorates cardiovascular disease

Baicalin is a flavonoid glycoside obtained from the dried root of Scutellaria baicalensis Georgi, which belongs to the Labiatae family. Accumulating evidence indicates that baicalin has favorable therapeutic effects on cardiovascular diseases. Previous studies have revealed the therapeutic effects of baicalin on atherosclerosis, myocardial ischemia/reperfusion injury, hypertension, and heart failure through anti-inflammatory, antioxidant, and lipid metabolism mechanisms. In recent years, some new ideas related to baicalin in ferroptosis, coagulation and fibrinolytic systems have been proposed, and new progress has been made in understanding the mechanism by which baicalin protects cardiomyocytes. However, many relevant underlying mechanisms remain unexplained, and much experimental data is lacking. Therefore, further research is needed to determine these mechanisms. In this review, we summarize the mechanisms of baicalin, which include its anti-inflammatory and antioxidant effects; inhibition of endothelial cell apoptosis; modulation of innate immunity; suppression of vascular smooth muscle cells proliferation, migration, and contraction; regulation of coagulation and fibrinolytic systems; inhibition of myocardial hypertrophy; prevention of myocardial fibrosis; and anti-apoptotic effects on cardiomyocytes.

PDZK1 confers sensitivity to sunitinib in clear cell renal cell carcinoma by suppressing the PDGFR-β pathway

BACKGROUND

Sunitinib has emerged as the primary treatment for advanced or metastatic clear cell renal cell carcinoma (ccRCC) due to its significant improvement in patients' average survival time. However, drug resistance and adverse effects of sunitinib pose challenges to its clinical benefits.

METHODS

The differentially expressed genes (DEGs) associated with sunitinib sensitivity and resistance in ccRCC were investigated. Cell counting kit-8, plate colony formation, flow cytometry and subcutaneous xenograft tumor model assays were employed to explore the effects of PDZK1 on ccRCC. Further research on the molecular mechanism was conducted through western blot, co-immunoprecipitation, immunofluorescence co-localization and immunohistochemical staining.

RESULTS

We elucidated that PDZK1 is significantly downregulated in sunitinib-resistant ccRCC specimens, and PDZK1 negatively regulates the phosphorylation of PDGFR-β and the activation of its downstream pathways through interaction with PDGFR-β. The dysregulated low levels of PDZK1 contribute to inadequate inhibition of cell proliferation, tumor growth, and insensitivity to sunitinib treatment. Notably, our preclinical investigations showed that miR-15b antagomirs enhance sunitinib cytotoxic effects against ccRCC cells by upregulating PDZK1 levels, suggesting their potential in overcoming sunitinib resistance.

CONCLUSIONS

Our findings establish the miR-15b/PDZK1/PDGFR-β axis as a promising therapeutic target and a novel predictor for ccRCC patients' response to sunitinib treatment.

Manuka honey's anti-metastatic impact on colon cancer stem-like cells: unveiling its effects on epithelial-mesenchymal transition, angiogenesis and telomere length

Colorectal cancer often leads to metastasis, with cancer stem cells (CSCs) playing a pivotal role in this process. Two closely linked mechanisms, epithelial-mesenchymal transition and angiogenesis, contribute to metastasis and recent research has also highlighted the impact of telomere replication on this harmful tumor progression. Standard chemotherapy alone can inadvertently promote drug-resistant CSCs, posing a challenge. Combining chemotherapy with other compounds, including natural ones, shows promise in enhancing effectiveness while minimizing side effects. This study investigated the anti-metastatic potential of Manuka honey, both alone and in combination with 5-fluorouracil, using a 3D model of colonospheres enriched with CSC-like cells. In summary, it was observed that the treatment reduced migration ability by downregulating the transcription factors Slug, Snail, and Twist, which are key players in epithelial-mesenchymal transition. Additionally, Manuka honey downregulated pro-angiogenic factors and shortened CSC telomeres by downregulating c-Myc - demonstrating an effective anti-metastatic potential. This study suggests new research opportunities for studying the impact of natural compounds when combined with pharmaceuticals, with the potential to enhance effectiveness and reduce side effects.

Dual-Specificity Phosphatase 6 Deficiency Attenuates Arterial-Injury-Induced Intimal Hyperplasia in Mice

In response to injury, vascular smooth muscle cells (VSMCs) of the arterial wall dedifferentiate into a proliferative and migratory phenotype, leading to intimal hyperplasia. The ERK1/2 pathway participates in cellular proliferation and migration, while dual-specificity phosphatase 6 (DUSP6, also named MKP3) can dephosphorylate activated ERK1/2. We showed that DUSP6 was expressed in low baseline levels in normal arteries; however, arterial injury significantly increased DUSP6 levels in the vessel wall. Compared with wild-type mice, Dusp6-deficient mice had smaller neointima. In vitro, IL-1β induced DUSP6 expression and increased VSMC proliferation and migration. Lack of DUSP6 reduced IL-1β-induced VSMC proliferation and migration. DUSP6 deficiency did not affect IL-1β-stimulated ERK1/2 activation. Instead, ERK1/2 inhibitor U0126 prevented DUSP6 induction by IL-1β, indicating that ERK1/2 functions upstream of DUSP6 to regulate DUSP6 expression in VSMCs rather than downstream as a DUSP6 substrate. IL-1β decreased the levels of cell cycle inhibitor p27 and cell-cell adhesion molecule N-cadherin in VSMCs, whereas lack of DUSP6 maintained their high levels, revealing novel functions of DUSP6 in regulating these two molecules. Taken together, our results indicate that lack of DUSP6 attenuated neointima formation following arterial injury by reducing VSMC proliferation and migration, which were likely mediated via maintaining p27 and N-cadherin levels.

Traditional Chinese medicine monomers: Targeting pulmonary artery smooth muscle cells proliferation to treat pulmonary hypertension

Pulmonary hypertension (PH) is a complex multifactorial disease characterized by increased pulmonary vascular resistance and pulmonary vascular remodeling (PVR), with high morbidity, disability, and mortality. The abnormal proliferation of pulmonary artery smooth muscle cells (PASMCs) is the main pathological change causing PVR. At present, clinical treatment drugs for PH are limited, which can only improve symptoms and reduce hospitalization but cannot delay disease progression and reduce survival rate. In recent years, numerous studies have shown that traditional Chinese medicine monomers (TCMs) inhibit excessive proliferation of PASMCs resulting in alleviating PVR through multiple channels and multiple targets, which has attracted more and more attention in the treatment of PH. In this paper, the experimental evidence of inhibiting PASMCs proliferation by TCMs was summarized to provide some directions for the future development of these mentioned TCMs as anti-PH drugs in clinical.

Multi-functional plant flavonoids regulate pathological microenvironments for vascular stent surface engineering

In-stent restenosis (ISR) and late thrombosis, usually caused by excessive smooth muscle cell (SMC) proliferation and delayed endothelial layer repair, respectively, are the main risks for the failure of vascular stent implantation. For years, modification of stents with biomolecules that could selectively inhibit SMC proliferation and support endothelial cell (EC) growth had drawn extensive attention. However, the modulatory effect of these biomolecules faces the impact of oxidative stress, inflammation, and hyperlipidemia of the pathological vascular microenvironment, which is caused by the stent implantation injury and atherosclerosis lesions. Here, we modified stents with a natural and multi-functional flavonoid, baicalin (BCL), using poly-dopamine (PDA) coating technology to combat the harmful impact of the pathological microenvironment. Stent with an appropriate BCL immobilization density (approximately 2.03 μg/cm2) successfully supported ECs growth while inhibited SMC proliferation. Furthermore, baicalin-modified surfaces regulated the oxidative stress, inflammation, and high-lipid of the pathological microenvironment to inhibit endothelial dysfunction and the oxidized low-density lipoprotein (ox-LDL)-induced macrophage foam cells formation. In vivo results showed that baicalin-modified stents exhibited significant anti-ISR, anti-inflammatory, and endothelialization-promoting functions. Our study suggests that the multi-functional baicalin with pathological microenvironment-regulation (PMR) effect has potential use in the surface engineering of cardiovascular devices. STATEMENT OF SIGNIFICANCE: Empowering vascular stents with selective modulation of smooth muscle cells and endothelial cells by surface technology has become an important research direction for stent surface engineering. However, stent coatings that can furthermodulate the pathological microenvironment of blood vessels have been rarely reported. In this study, we constructed a multifunctional coating based on a flavonoid, baicalin, which can selectively modulate vascular wall cells and improve the pathological microenvironment. This study may provide a reference for developing advanced vascular stents.

Deciphering the Mechanism of Wogonin, a Natural Flavonoid, on the Proliferation of Pulmonary Arterial Smooth Muscle Cells by Integrating Network Pharmacology and In Vitro Validation

Wogonin is one of the main active components of Scutellaria baicalensis, which has anti-inflammatory, anti-angiogenesis, and anti-fibrosis effects. Nevertheless, the effect of wogonin on pulmonary hypertension (PH) still lacks systematic research. This study aims to elucidate the potential mechanism of wogonin against PH through network pharmacology and further verify it through biological experiments in pulmonary arterial smooth muscle cells (PASMCs). The potential targets and pathways of wogonin against PH were predicted and analyzed by network pharmacology methods and molecular docking technology. Subsequently, the proliferation of PASMCs was induced by platelet-derived growth factor-BB (PDGF-BB). Cell viability and migration ability were examined. The method of Western blot was adopted to analyze the changes in related signaling pathways. Forty potential targets related to the effect of wogonin against PH were obtained. Based on the protein-protein interaction (PPI) network, gene-ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment, and molecular docking, it was shown that the effect of wogonin against PH is closely related to the proliferation of PASMCs and the hypoxia-inducible factor-1α (HIF-1α) pathway. A variety of results from biological experiments verified that wogonin can effectively inhibit the proliferation, migration, and phenotypic transformation of PDGF-BB-mediated PASMCs. In addition, the anti-proliferation effect of wogonin may be achieved by regulating HIF-1/ NADPH oxidase 4 (NOX4) pathway.

Role of hsa_circ_0000280 in regulating vascular smooth muscle cell function and attenuating neointimal hyperplasia via ELAVL1

The pathological proliferation of cells in vascular smooth muscle underlies neointimal hyperplasia (NIH) development during atherosclerosis. Circular RNAs (circRNAs), which represent novel functional biomarkers and RNA-binding proteins, contribute to multiple cardiovascular diseases; however, their roles in regulating the vascular smooth muscle cell cycle remain unknown. Thus, we aimed to identify the roles of circRNAs in vascular smooth muscle during coronary heart disease (CHD). Through circRNA sequencing of CHD samples and human antigen R (ELAVL1) immunoprecipitation, we identified circRNAs that are associated with CHD and interact with ELAVL1. Our results suggested that the hsa_circ_0000280 associated with CHD inhibits cell proliferation and induces ELAVL1-dependent cell cycle arrest. Gain/loss-of-function experiments and assays in vivo indicated that hsa_circ_0000280 facilitates interactions between ELAVL1 and cyclin-dependent kinase suppressor 1 (CDKN1A) mRNA and stabilization of this complex and leads to cell cycle arrest at the G1/S checkpoint, inhibiting cell proliferation of vascular smooth muscle cells in vitro and NIH in vivo. Importantly, hsa_circ_0000280 reduced neointimal thickness and smooth muscle cell proliferation in vivo. Taken together, these findings reveal a novel pathway in which hsa_circ_0000280 facilitates the regulation of ELAVL1 on CDKN1A mRNA to inhibit NIH. Therefore, measuring and modulating their expression might represent a potential diagnostic or therapeutic strategy for CHD.

Exploring the protective mechanism of baicalin in treatment of atherosclerosis using endothelial cells deregulation model and network pharmacology

Background

Baicalin is a generally available flavonoid with potent biological activity. The present study aimed to assess the underlying mechanism of baicalin in treatment of atherosclerosis (AS) with the help of network pharmacology, molecular docking and experimental validation.

Methods

The target genes of baicalin and AS were identified from public databases, and the overlapping results were considered to be baicalin-AS targets. Core target genes of baicalin were obtained through the PPI network and validated by a clinical microarray dataset (GSE132651). Human aortic endothelial cells (HAECs) were treated with Lipopolysaccharide (LPS) to construct an endothelial injury model. The expression of NOX4 was examined by real-time qPCR and western blot. Flow cytometry was used to detect intracellular levels of reactive oxygen species (ROS). Furthermore, HAECs were transfected with NOX4-specific siRNA and then co-stimulated with baicalin and LPS to investigate whether NOX4 was involved in the anti-oxidative stress effects of baicalin.

Results

In this study, baicalin had 45 biological targets against AS. Functional enrichment analysis demonstrated that most targets were involved in oxidative stress. Using the CytoHubba plug-in, we obtained the top 10 genes in the PPI network ranked by the EPC algorithm. Molecular docking and microarray dataset validation indicated that NOX4 may be an essential target of baicalin, and its expression was significantly suppressed in AS samples compared to controls. In endothelial injury model, intervention of HAECs with baicalin increased the expression levels of NOX4 and NOS3 (eNOS), and decreased LPS-induced ROS generation. After inhibition of NOX4, the anti-ROS-generating effect of baicalin was abolished.

Conclusion

Collectively, we combined network pharmacology and endothelial injury models to investigate the anti-AS mechanism of baicalin. The results demonstrate that baicalin may exert anti-oxidative stress effects by targeting NOX4, providing new mechanisms and insights to baicalin for the treatment of AS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03738-3.

Bves maintains vascular smooth muscle cell contractile phenotype and protects against transplant vasculopathy via Dusp1-dependent p38MAPK and ERK1/2 signaling

BACKGROUND AND AIMS

Vascular smooth muscle cell (VSMC) plasticity is tightly associated with the pathological process of vasculopathy. Blood vessel epicardial substance (Bves) has emerged as an important regulator of intracardiac vasculogenesis and organ homeostasis. However, the involvement and role of Bves in VSMC plasticity and neointimal lesion development remain unclear.

METHODS

We used an in vivo rat model of graft arteriosclerosis and in vitro PDGF-treated VSMCs and identified the novel VSMC contractile phenotype-related gene Bves using a transcriptomic analysis and literature search. In vitro knockdown and overexpression approaches were used to investigate the mechanisms underlying VSMC phenotypic plasticity. In vivo, VSMC-specific Bves overexpression in rat aortic grafts was generated to assess the physiological function of Bves in neointimal lesion development.

RESULTS

Here, we found that Bves expression was negatively regulated in aortic allografts in vivo and PDGF-treated VSMCs in vitro. The genetic knockdown of Bves dramatically inhibited, whereas Bves overexpression markedly promoted, the VSMC contractile phenotype. Furthermore, RNA sequencing unraveled a positive correlation between Bves and dual-specificity protein phosphatase 1 (Dusp1) expression in VSMCs. We found that Bves knockdown restrained Dusp1 expression, but enhanced p38MAPK and ERK1/2 activation, resulting in the loss of the VSMC contractile phenotype. In vivo, an analysis of a rat graft model confirmed that VSMC-specific Bves and Dusp1 overexpression in aortic allografts significantly attenuated neointimal lesion formation.

CONCLUSIONS

Bves maintains the VSMC contractile phenotype through Dusp1-dependent p38MAPK and ERK1/2 signaling, and protects against neointimal formation, underscoring the important role of Bves in preventing transplant vasculopathy.

Engineering Bioactive M2 Macrophage-Polarized, Anti-inflammatory, miRNA-Based Liposomes for Functional Muscle Repair: From Exosomal Mechanisms to Biomaterials

Severe inflammation and myogenic differentiation disorder are the major obstacles to skeletal muscle healing after injury. MicroRNAs (miRNAs) play an important role as regulatory molecules during the process of muscle healing, but the detailed mechanism of miRNA-mediated intercellular communication between myoblasts and macrophages remains unclear. Here, it is reported that myoblasts secrete miRNAs-enriched exosomes in the inflammatory environment, through which miR-224 is transferred into macrophages to inhibit M2 polarization. Further data demonstrate that WNT-9a may be a direct target of miR-224 for macrophage polarization. In turn, the secretome of M1 macrophages impairs myogenic differentiation and promotes proliferation. Single-cell integration analysis suggests that the elevation of exosome-derived miR-224 is caused by the activation of the key factor E2F1 in myoblasts and demonstrates the RB/E2F1/miR-224/WNT-9a axis. In vivo results show that treatment with antagomir-224 or liposomes containing miR-224 inhibitors suppresses fibrosis and improves muscle recovery. These findings indicate the importance of the crosstalk between myoblasts and macrophages via miRNA-containing exosomes in the regulation of macrophage polarization and myogenic differentiation/proliferation during muscle healing. This study provides a strategy for treating muscle injury through designing an M2 polarization-enabling anti-inflammatory and miRNA-based bioactive material.

The Etiology and Molecular Mechanism Underlying Smooth Muscle Phenotype Switching in Intimal Hyperplasia of Vein Graft and the Regulatory Role of microRNAs

Mounting evidence suggests that the phenotypic transformation of venous smooth muscle cells (SMCs) from differentiated (contractile) to dedifferentiated (proliferative and migratory) phenotypes causes excessive proliferation and further migration to the intima leading to intimal hyperplasia, which represents one of the key pathophysiological mechanisms of vein graft restenosis. In recent years, numerous miRNAs have been identified as specific phenotypic regulators of vascular SMCs (VSMCs), which play a vital role in intimal hyperplasia in vein grafts. The review sought to provide a comprehensive overview of the etiology of intimal hyperplasia, factors affecting the phenotypic transformation of VSMCs in vein graft, and molecular mechanisms of miRNAs involved in SMCs phenotypic modulation in intimal hyperplasia of vein graft reported in recent years.

Mechanistic and therapeutic perspectives of baicalin and baicalein on pulmonary hypertension: A comprehensive review

Pulmonary hypertension (PH) is a chronic and fatal disease, for which new therapeutic drugs and approaches are needed urgently. Baicalein and baicalin, the active compounds of the traditional Chinese medicine, Scutellaria baicalensis Georgi, exhibit a wide range of pharmacological activities. Numerous studies involving in vitro and in vivo models of PH have revealed that the treatment with baicalin and baicalein may be effective. This review summarizes the potential mechanisms driving the beneficial effects of baicalin and baicalein treatment on PH, including anti-inflammatory response, inhibition of pulmonary smooth muscle cell proliferation and endothelial-to-mesenchymal transformation, stabilization of the extracellular matrix, and mitigation of oxidative stress. The pharmacokinetics of these compounds have also been reviewed. The therapeutic potential of baicalin and baicalein warrants their continued study as natural treatments for PH.

CFTR Suppresses Neointimal Formation Through Attenuating Proliferation and Migration of Aortic Smooth Muscle Cells

ABSTRACT

Cystic fibrosis transmembrane conductance regulator (CFTR) plays important roles in arterial functions and the fate of cells. To further understand its function in vascular remodeling, we examined whether CFTR directly regulates platelet-derived growth factor-BB (PDGF-BB)-stimulated vascular smooth muscle cells (VSMCs) proliferation and migration, as well as the balloon injury-induced neointimal formation. The CFTR adenoviral gene delivery was used to evaluate the effects of CFTR on neointimal formation in a rat model of carotid artery balloon injury. The roles of CFTR in PDGF-BB-stimulated VSMC proliferation and migration were detected by mitochondrial tetrazolium assay, wound healing assay, transwell chamber method, western blot, and qPCR. We found that CFTR expression was declined in injured rat carotid arteries, while adenoviral overexpression of CFTR in vivo attenuated neointimal formation in carotid arteries. CFTR overexpression inhibited PDGF-BB-induced VSMC proliferation and migration, whereas CFTR silencing caused the opposite results. Mechanistically, CFTR suppressed the phosphorylation of PDGF receptor β, serum and glucocorticoid-inducible kinase 1, JNK, p38 and ERK induced by PDGF-BB, and the increased mRNA expression of matrix metalloproteinase-9 and MMP2 induced by PDGF-BB. In conclusion, our results indicated that CFTR may attenuate neointimal formation by suppressing PDGF-BB-induced activation of serum and glucocorticoid-inducible kinase 1 and the JNK/p38/ERK signaling pathway.

Evening Primrose Extracts Inhibit PDGF-BB-Induced Vascular Smooth Muscle Cell Proliferation and Migration by Regulating Cell-Cycle-Related Proteins

The proliferation and migration of vascular smooth muscle cells (VSMCs) are important factors in the occurrence of cardiovascular diseases, such as blood flow abnormalities, stroke and atherosclerosis. Evening primrose, known as Oenothera biennis, is a plant native to Korea that exerts physiological activities, such as antioxidant effects, the inhibition of lipid accumulation and the prevention of muscle atrophy. However, the function of evening primrose stem (EVP) in the regulation of VSMC proliferation and migration and the underlying mechanisms have not been identified. In this study, the effect of EVP on the platelet-derived growth factor (PDGF)-induced proliferation and migration of VSMCs was investigated. The results show that PDGF-BB-induced proliferation of VSMCs was inhibited by EVP at concentrations of 25, 50 or 100 μg/mL in a concentration-dependent manner, and a migration assay showed that EVP inhibited cell migration. Cell cycle analysis was performed to confirm the mechanism by which cell proliferation and migration was inhibited. The results indicate that proteins involved in the cell cycle, such as cyclin, CDK and phosphorylated Rb, were downregulated by EVP at concentrations of 100 μg/mL, thereby increasing the proportion of cells in the G0/G1 phase and inhibiting cell cycle progression. In the PDGF receptor (PDGFR) signaling pathway, phosphorylation of the PDGFR was inhibited by EVP at concentrations of 100 μg/mL, and PLCγ phosphorylation was also decreased. The PDGF-BB-induced effect of EVP on the proliferation of VSMCs involved the inhibition of Akt phosphorylation and the reduction in the phosphorylation of MAPK proteins such as ERK, P38 and JNK. In conclusion, the results demonstrate that EVP inhibited PDGF-BB-induced VSMC proliferation and migration by regulating cell-cycle-related proteins.

Kisspeptins inhibit human airway smooth muscle proliferation

Sex/gender disparity in asthma is recognized, and suggests a modulatory role for sex-steroids, particularly estrogen. However, studies including our own show a dichotomous role for estrogen in airway remodeling, making it unclear whether sex hormones are protective or detrimental in asthma, and suggesting a need to explore mechanisms upstream or independent of estrogen. We hypothesize that Kisspeptin (Kp)/KISS1R signaling serves this role. Airway smooth muscle (ASM) is a key structural cell type that contributes to remodeling in asthma. We explored the role of Kp/KISS1R in regulating ASM proliferation. We report novel data that Kp and KISS1R are expressed in human airways, especially ASM, with lower expression in ASM from females compared to males, and asthmatics showing lowest expression compared to non-asthmatics. Proliferation studies showed that cleaved forms of Kp, particularly Kp-10 mitigates PDGF-induced ASM proliferation. Pharmacological inhibition and shRNA knockdown of KISS1R increased basal ASM proliferation, further amplified by PDGF. The anti-proliferative effect of Kp-10 in ASM was found to be mediated by inhibition of MAPK-ERK-Akt pathways, with altered expression of PCNA, C/EBP-alpha, Ki-67, Cyclin-D1, and Cyclin-E leading to cell-cycle arrest at G0/G1 phase. Overall, we demonstrate the importance of Kp/KISS1R signaling in regulating ASM proliferation and a potentially novel therapeutic avenue to blunt remodeling in asthma.

Dynamics and Functional Interplay of Nonhistone Lysine Crotonylome and Ubiquitylome in Vascular Smooth Muscle Cell Phenotypic Remodeling

Background

The crotonylation of histones is discovered of late as one of the post-translational modifications (PTMs) that can regulate gene expression. However, the function of crotonylation on nonhistone proteins in vascular smooth muscle cells (VSMCs) is unclear. Here, we aim to find the cellular characteristics of crotonylated nonhistone proteins and the cross talk with ubiquitinated proteins in VSMC phenotypic remodeling using the modified omics and proteomic analysis.

Methods

We performed the modified omics and proteomic analysis of VSMCs before and after the stimulation with platelet-derived growth factor-BB (PDGF-BB). The crotonylated and ubiquitinated pan-antibody was used to enrich proteins and then subjected to a high-throughput mass spectrometry analysis. The enrichment analysis was performed within differentially modified proteins in regard to GO terms, KEGG, and protein domains.

Results

As a result, there were 2,138 crotonylation sites in 534 proteins and 1,359 ubiquitination sites corresponding to 657 proteins. These crotonylated proteins detected after PDGF-BB stimulation might be involved in various vital cellular pathways and carry out important functions in VSMCs. Some of them closely took part in significant physiological processes of VSMC phenotypic remodeling, including glycolysis/gluconeogenesis, vascular smooth muscle contraction, and the PI3K-Akt signaling pathway. Furthermore, the KEGG pathway enrichment analysis showed the involvement of ubiquitinated proteins in the physiological processes of VSMC phenotypic remodeling, including glycolysis/gluconeogenesis, vascular smooth muscle contraction, RAS signaling pathway, or the PI3K-Akt signaling pathway. A cross talk analysis showed that there were 199 sites within the 177 proteins modified by crotonylation and ubiquitination simultaneously. Protein–protein interaction (PPI) network analysis indicated that crotonylated and ubiquitinated proteins play an important role in cellular bioprocess commonly and possibly have a synergistic effect.

Conclusion

In summary, our bioinformatics analysis shows that the crotonylation and ubiquitination of nonhistone proteins play an essential role in VSMC phenotypic transformation induced by PDGF-BB stimulation. The cross talk between crotonylation and ubiquitination in glycolysis is possibly a novel mechanism during VSMC phenotypic remodeling.

Sulfiredoxin-1 Inhibits PDGF-BB-Induced Vascular Smooth Muscle Cell Proliferation and Migration by Enhancing the Activation of Nrf2/ARE Signaling

Sulfiredoxin1 (Srxn1), an endogenous antioxidant protein, is involved in cardiovascular diseases. In this study, we aimed to investigate the role of Srxn1 in VSMCs and its molecular mechanism. The murine vascular smooth muscle cells MOVAS were treated with different doses of platelet-derived growth factor-BB (PDGF-BB); then, Srxn1 expression was detected using reverse transcription-quantitative polymerase chain reaction and western blot analysis. MTT and wound healing assay were used to examine the effect of Srxn1 on MOVAS cell proliferation and migration. Reactive oxygen species (ROS) production, malondialdehyde (MDA) level, and superoxide dismutase (SOD) activity in MOVAS cells were detected using corresponding commercial kits. Moreover, the expression of proliferating cell nuclear antigen (PCNA), matrix metalloproteinase 2 (MMP-2), and nuclear factor erythroid-2-related factor 2 (Nrf2) /antioxidant response element (ARE) signaling-related proteins was detected using western blot analysis. In our study, PDGF-BB dose-dependently increased Srxn1 expression in MOVAS cells, and Srxn1 expression was increased with time dependence in PDGF-BB-treated MOVAS cells. The knockdown of Srxn1 increased PDGF-BB-induced the proliferation, migration, ROS production, MDA level, and the protein expression of PCNA and MMP-2, as well as decreased SOD activity and the expression of Nrf2/ARE signaling-related proteins in PDGF-BB-stimulated MOVAS cells. However, the overexpression of Srxn1 showed the opposite results to those of knockdown of Srxn1. Moreover, the inhibitory effects of Srxn1 overexpression on PDGF-BB induced proliferation, migration, ROS production, and MDA level and the promotion of Srxn1 overexpression on PDGF-BB induced SOD activity were partially reversed by the knockdown of Nrf2. Srxn1 inhibited PDGF-BB-induced proliferation, migration, and oxidative stress through activating Nrf2/ARE signaling.

An overview of pharmacological activities of baicalin and its aglycone baicalein: New insights into molecular mechanisms and signaling pathways

The flavonoids, baicalin, and its aglycone baicalein possess multi-fold therapeutic properties and are mainly found in the roots of Oroxylum indicum (L.) Kurz and Scutellaria baicalensis Georgi. These flavonoids have been reported to possess various pharmacological properties, including antibacterial, antiviral, anticancer, anticonvulsant, anti-oxidant, hepatoprotective, and neuroprotective effects. The pharmacological properties of baicalin and baicalein are due to their abilities to scavenge reactive oxygen species (ROS) and interaction with various signaling molecules associated with apoptosis, inflammation, autophagy, cell cycle, mitochondrial dynamics, and cytoprotection. In this review, we summarized the molecular mechanisms underlying the chemopreventive and chemotherapeutic applications of baicalin and baicalein in the treatment of cancer and inflammatory diseases. In addition, the preventive effects of baicalin and baicalein on mitochondrial dynamics and functions were highlighted with a particular emphasis on their anti-oxidative and cytoprotective properties. The current review highlights could be useful for future prospective studies to further improve the pharmacological applications of baicalein and baicalin. These studies should define the threshold for optimal drug exposure, dose optimization and focus on therapeutic drug monitoring, objective disease markers, and baicalin/baicalein drug levels.

Baicalin attenuates angiotensin II-induced blood pressure elevation and modulates MLCK/p-MLC signaling pathway

Scutellaria baicalensis Georgi is an extensively used medicinal herb for the treatment of hypertension in traditional Chinese medicine. Baicalin, is an important flavonoid in Scutellaria baicalensis Georgi extracts, which exhibits therapeutic effects on anti-hypertension, but its underlying mechanisms remain to be further explored. Therefore, we investigated the effects and molecular mechanisms of Baicalin on anti-hypertension. In vivo studies revealed that Baicalin treatment significantly attenuated the elevation in blood pressure, the pulse propagation and thickening of the abdominal aortic wall in C57BL/6 mice infused with Angiotensin II (Ang II). Moreover, RNA-sequencing and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses identified 537 differentially expressed transcripts and multiple enriched signaling pathways (including vascular smooth muscle contraction and calcium signaling pathway). Consistently, we found that Baicalin pretreatment significantly alleviated the Ang II induced constriction of abdominal aortic ring, while promoted NE pre-contracted vasodilation of abdominal aortic ring at least partly dependent on L-type calcium channel. In addition, Ang II stimulation significantly increased cell viability and PCNA expression, while were attenuated after Baicalin treatment. Moreover, Baicalin pretreatment attenuated Ang II-induced intracellular Ca2+ release, Angiotensin II type 1 receptor (AT1R) expression and activation of MLCK/p-MLC pathway in vascular smooth muscle cells (VSMCs). The present work further addressed the pharmacological and mechanistic insights on anti-hypertension of Baicalin, which may help better understand the therapeutic effect of Scutellaria baicalensis Georgi on anti-hypertension.

BOP1 Knockdown Attenuates Neointimal Hyperplasia by Activating p53 and Inhibiting Nascent Protein Synthesis

The rate of ribosome biogenesis plays a vital role in cell cycle progression and proliferation and is strongly connected with coronary restenosis and atherosclerosis. Blocking of proliferation 1 (BOP1) has been found as an evolutionarily conserved gene and a pivotal regulator of ribosome biogenesis and cell proliferation. However, little is known about its role in neointimal formation and its relationship with vascular smooth muscle cell (VSMC) proliferation and migration. The present study mainly explores the effect of BOP1 on VSMCs, the progression of neointimal hyperplasia, and the pathogenic mechanism. The expression of BOP1 was found to be significantly elevated during neointimal formation in human coronary samples and the rat balloon injury model. BOP1 knockdown inspires the nucleolus stress, which subsequently activates the p53-dependent stress response pathway, and inhibits the nascent protein synthesis, which subsequently inhibits the proliferation and migration of VSMCs. Knockdown ribosomal protein L11 (RPL11) by transfecting with siRNA or inhibiting p53 by pifithrin-α (PFT-α) partly reserved the biological effects induced by BOP1 knockdown. The present study revealed that BOP1 deletion attenuates VSMC proliferation and migration by activating the p53-dependent nucleolus stress response pathway and inhibits the synthesis of nascent proteins. BOP1 may become a novel biological target for neointimal hyperplasia.

Shuxuetong injection simultaneously ameliorates dexamethasone-driven vascular calcification and osteoporosis

Osteoporosis (OP) and vascular calcification (VC) share a number of common risk factors, pathophysiological mechanisms and etiology, which are known as bone-vascular axis. The present study aimed to investigate the effects of Shuxuetong (SXT) injection on VC and osteoporosis. A rat model of VC and osteoporosis was induced by dexamethasone (DEX; 1 mg/kg/day for 4 weeks, intramuscularly). Simultaneously, 0.6 ml/kg/day SXT was intraperitoneally injected. Compared with control rats, DEX induced significantly more VC and OP, as determined by increased calcium deposition and alkaline phosphatase activity in the aorta, disturbed structure, decreased levels of cortical bone thickness and trabecular bone area, and increased apoptosis in the bone. SXT injection ameliorated DEX-induced VC and osteoporosis; furthermore, the osteoblastic differentiation of vascular smooth muscle cells and the activation of endoplasmic reticulum stress in the DEX group was also prevented by SXT injection. Compared with control rats, protein expression levels of sclerostin, a crucial crosslink of the bone-vascular axis, were significantly increased in the aorta and bone of rats with DEX, which was also attenuated by SXT injection. Thus, the present study suggested that SXT injection could ameliorate both VC and OP, and may be mediated by the regulation of sclerostin. The present study may provide the basis a novel strategy for the prevention and treatment of VC and OP, which emerge as side-effects of glucocorticoids.

Antitumor Activity In Vivo and Vitro of New Chiral Derivatives of Baicalin and Induced Apoptosis via the PI3K/Akt Signaling Pathway

In this study, a pair of chiral baicalin (BA) derivatives were synthesized by combining BA with phenylalanine methyl ester based on molecular docking technology, namely BAD and BAL. Cell cytotoxicity trails showed that the cell growth inhibitory effects of both BAD and BAL were increased by 8- to 12-fold compared with BA on A549 cells. Flow cytometry showed that the apoptotic rates of 50 μg/mL BA, BAD, and BAL to A549 cells for 48 h were 17.94%, 24.32%, and 39.69%, respectively. Western blotting analysis showed that BAD and BAL could promote Bax, caspase-3, and caspase-9 expression and inhibit Bcl-2 expression by inhibiting the expression of p-Akt. The tumor inhibition rates of BA, BAD, and BAL in nude mice of tumor-bearing experiment lasting for 24 days were 35.01%, 53.30%, and 59.35%, respectively. These results in vitro and in vivo showed that BAL had higher antitumor activity than did BAD and BA, which were related to promotion of the apoptosis of tumor cells by inhibiting the expression of p-Akt on PI3K/Akt pathway. This study provides an experimental basis for the development of a new configuration of BA for the treatment of cancer.

Uterine decidual niche modulates the progressive dedifferentiation of spiral artery vascular smooth muscle cells during human pregnancy†

Uterine spiral artery (SPA) remodeling is a crucial event during pregnancy to provide enough blood supply to maternal-fetal interface and meet the demands of the growing fetus. Along this process, the dynamic change and the fate of spiral artery vascular smooth muscle cells (SPA-VSMCs) have long been debatable. In the present study, we analyzed the cell features of SPA-VSMCs at different stages of vascular remodeling in human early pregnancy, and we demonstrated the progressively morphological change of SPA-VSMCs at un-remodeled (Un-Rem), remodeling, and fully remodeled (Fully-Rem) stages, indicating the extravillous trophoblast (EVT)-independent and EVT-dependent phases of SPA-VSMC dedifferentiation. In vitro experiments in VSMC cell line revealed the efficient roles of decidual stromal cells, decidual natural killer cells (dNK), decidual macrophages, and EVTs in inducing VSMCs dedifferentiation. Importantly, the potential transformation of VSMC toward CD56+ dNKs was displayed by immunofluorescence-DNA in-situ hybridization-proximity ligation and chromatin immunoprecipitation assays for H3K4dime modification in the myosin heavy chain 11 (MYH11) promoter region. The findings clearly illustrate a cascade regulation of the progressive dedifferentiation of SPA-VSMCs by multiple cell types in uterine decidual niche and provide new evidences to reveal the destination of SPA-VSMCs during vascular remodeling.

Medicinal Plants and Phytochemicals for the Treatment of Pulmonary Hypertension

Background

Pulmonary hypertension (PH) is a progressive disease that is associated with pulmonary arteries remodeling, right ventricle hypertrophy, right ventricular failure and finally death. The present study aims to review the medicinal plants and phytochemicals used for PH treatment in the period of 1994 – 2019.

Methods

PubMed, Cochrane and Scopus were searched based on pulmonary hypertension, plant and phytochemical keywords from August 23, 2019. All articles that matched the study based on title and abstract were collected, non-English, repetitive and review studies were excluded.

Results

Finally 41 studies remained from a total of 1290. The results show that many chemical treatments considered to this disease are ineffective in the long period because they have a controlling role, not a therapeutic one. On the other hand, plants and phytochemicals could be more effective due to their action on many mechanisms that cause the progression of PH.

Conclusion

Studies have shown that herbs and phytochemicals used to treat PH do their effects from six mechanisms. These mechanisms include antiproliferative, antioxidant, antivascular remodeling, anti-inflammatory, vasodilatory and apoptosis inducing actions. According to the present study, many of these medicinal plants and phytochemicals can have effects that are more therapeutic than chemical drugs if used appropriately.

Baicalin relieves TNF-α-evoked injury in human aortic endothelial cells by up-regulation of miR-145

Hypertension is recognized to be associated with low-grade inflammation. Baicalin (BAI) is reported to possess various pharmacological including anti-inflammatory activities. This research explored the molecular mechanism by which BAI functions in human aortic endothelial cells (HAECs). HAECs were pretreated with BAI. Cell viability, apoptosis, and expressions of crucial proteins were respectively evaluated using cell counting kit-8 assay, flow cytometry, and western blot. Productions of cytokines were respectively assessed employing quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Cell transfection was utilized to alter miR-145 expression. The expressions of proteins participated in JNK and p38MAPK pathways were analyzed utilizing western blot. TNF-α inducement successfully evoked inflammatory injury in HAECs, exhibiting as prominently suppressed viability, while facilitated apoptosis and productions of cytokines. However, BAI pretreatment significantly ameliorated TNF-α-triggered inflammatory injuries. Besides, miR-145 expression was markedly inhibited by TNF-α inducement, while notably elevated by BAI pretreatment. Although miR-145 overexpression had no significant influence on apoptosis, miR-145 silence observably reversed BAI pretreatment-evoked protective influences on TNF-α-induced HAECs, as well as the inhibited impacts on the levels of key proteins involved in JNK and p38MAPK pathways. This investigation illustrated that BAI relieved TNF-α-triggered injuries through upregulating miR-145 via suppressing JNK and p38MAPK pathways.

Baicalin inhibits growth and induces apoptosis of human osteosarcoma cells by suppressing the AKT pathway

Osteosarcoma (OS) is one of the most prevalent types of bone malignancies with poor overall prognosis, and is reported mainly in children and adolescents. Therefore, the investigation of novel and efficient treatment strategies for patients with OS is required. Baicalin exhibits potential anticancer effects, including in OS. However, its therapeutic effect against OS and the underlying mechanisms have not been fully evaluated. In the present study, the effect of baicalin on the proliferation and apoptosis of OS cells and its underlying mechanism of AKT pathway activation was explored. Cell confluence and cell number counts revealed suppressed the growth of OS cells that were treated with baicalin. Analysis of cell viability, cell survival and cell cycle, as well as cell apoptosis revealed decreased cell viability and survival, induced cell cycle arrest and apoptosis of treated cells. Western blot analysis demonstrated significantly decreased ratios of phosphorylated-AKT/AKT and Bcl-2/Bax, and decreased protein levels of cyclin D1 and CDK4 in cells treated with baicalin. Thus, the findings from the present study suggest that the suppression of the AKT pathway may be the underlying mechanism of the antitumor effect of baicalin in OS cells.

RTA 408 Inhibits Interleukin-1β-Induced MMP-9 Expression via Suppressing Protein Kinase-Dependent NF-κB and AP-1 Activation in Rat Brain Astrocytes

Neuroinflammation is characterized by the elevated expression of various inflammatory proteins, including matrix metalloproteinases (MMPs), induced by various pro-inflammatory mediators, which play a critical role in neurodegenerative disorders. Interleukin-1β (IL-1β) has been shown to induce the upregulation of MMP-9 through nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX)-reactive oxygen species (ROS)-dependent signaling pathways. N-(2-cyano-3,12-dioxo-28-noroleana-1,9(11)-dien-17-yl)-2-2-difluoropropanamide (RTA 408), a novel synthetic triterpenoid, has been shown to possess anti-oxidant and anti-inflammatory properties in various types of cells. Here, we evaluated the effects of RTA 408 on IL-1β-induced inflammatory responses by suppressing MMP-9 expression in a rat brain astrocyte (RBA-1) line. IL-1β-induced MMP-9 protein and mRNA expression, and promoter activity were attenuated by RTA 408. The increased level of ROS generation in RBA-1 cells exposed to IL-1β was attenuated by RTA 408, as determined by using 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) and CellROX. In addition, the inhibitory effects of RTA 408 on MMP-9 expression resulted from the suppression of the IL-1β-stimulated activation of Pyk2 (proline-rich tyrosine kinase), platelet-derived growth factor receptor β (PDGFRβ), Akt, ROS, and mitogen-activated protein kinases (MAPKs). Pretreatment with RTA 408 attenuated the IL-1β-induced c-Jun phosphorylation, mRNA expression, and promoter activity. IL-1β-stimulated nuclear factor-κB (NF-κB) p65 phosphorylation, translocation, and promoter activity were also attenuated by RTA 408. Furthermore, IL-1β-induced glial fibrillary acidic protein (GFAP) protein and mRNA expression, and cell migration were attenuated by pretreatment with RTA 408. These results provide new insights into the mechanisms by which RTA 408 attenuates IL-1β-mediated inflammatory responses and exerts beneficial effects for the management of brain diseases.

Anti-proliferative and anti-migratory effects of Scutellaria strigillosa Hemsley extracts against vascular smooth muscle cells

ETHNOPHARMACOLOGICAL RELEVANCE

The abnormal increase in vascular smooth muscle cell (VSMC) proliferation and migration are critical events in the pathogenesis of cardiovascular diseases (CVDs) including restenosis and atherosclerosis. The dried roots of Scutellaria baicalensis Georgi (common name: Huangqin in China) have been confirmed to possess beneficial effects on CVD by clinical and modern pharmacological studies. Flavonoids in Huangqin exert anti-proliferative and anti-migratory effects. Similar to Huangqin, Scutellaria strigillosa Hemsley (SSH) has been used to clear heat and damp and is especially rich in flavonoids including wogonin, wogonoside, baicalein, and baicalin. However, there have been few of reports about pharmacological activities of SSH.

AIM OF THE STUDY

To investigate the anti-proliferative and anti-migratory properties of Scutellaria strigillosa Hemsley extract (SSHE) in vitro and in vivo and explore its possible mechanism of action.

MATERIALS AND METHODS

The chemical constituents of SSHE were analyzed by ultra-high performance liquid chromatography coupled with triple time-of-flight mass spectrometry (UPLC-Triple-TOF-MS/MS). Cell proliferation and migration were investigated using BrdU incorporation assay and cell scratch test, respectively. The protein expression was determined by western blotting. In vivo, we established an artery ligation model of C57BL/6 mice and orally administered them with 50 or 100 mg/kg/day of SSHE. The carotid arteries were harvested and the intima-media thickness was examined 28 days post-ligation.

RESULTS

Twelve compounds were identified and tentatively characterized. SSHE significantly inhibited the VSMC proliferation and migration stimulated by PDGF-BB and decreased the relative protein expression of regulatory signaling intermediates. Furthermore, the expression of SM22α was significantly elevated in SSHE-pretreated VSMCs, whereas knockdown of SM22α impaired the PDGF-BB-induced proliferation and migration arrest. Meanwhile, both ROS generation and the phosphorylation of ERK decreased in SSHE-pretreated VSMCs. In carotid artery ligation mice model, SSHE treatment significantly inhibited neointimal hyperplasia.

CONCLUSIONS

SSHE significantly inhibited the PDGF-BB-induced VSMC proliferation, migration, and neointimal hyperplasia of carotid artery caused by ligation. Upregulation of SM22α expression, inhibition of ROS generation and ERK phosphorylation were, at least, partly responsible for the effects of SSHE on VSMCs.

Semaphorin-3A protects against neointimal hyperplasia after vascular injury

BACKGROUND

Neointimal hyperplasia is a prominent pathological event during in-stent restenosis. Phenotype switching of vascular smooth muscle cells (VSMCs) from a differentiated/contractile to a dedifferentiated/synthetic phenotype, accompanied by migration and proliferation of VSMCs play an important role in neointimal hyperplasia. However, the molecular mechanisms underlying phenotype switching of VSMCs have yet to be fully understood.

METHODS

The mouse carotid artery ligation model was established to evaluate Sema3A expression and its role during neointimal hyperplasia in vivo. Bioinformatics analysis, chromatin immunoprecipitation (ChIP) assays and promoter-luciferase reporter assays were used to examine regulatory mechanism of Sema3A expression. SiRNA transfection and lentivirus infection were performed to regulate Sema3A expression. EdU assays, Wound-healing scratch experiments and Transwell migration assays were used to assess VSMC proliferation and migration.

FINDINGS

In this study, we found that semaphorin-3A (Sema3A) was significantly downregulated in VSMCs during neointimal hyperplasia after vascular injury in mice and in human atherosclerotic plaques. Meanwhile, Sema3A was transcriptionally downregulated by PDGF-BB via p53 in VSMCs. Furthermore, we found that overexpression of Sema3A inhibited VSMC proliferation and migration, as well as increasing differentiated gene expression. Mechanistically, Sema3A increased the NRP1-plexin-A1 complex and decreased the NRP1-PDGFRβ complex, thus inhibiting phosphorylation of PDGFRβ. Moreover, we found that overexpression of Sema3A suppressed neointimal hyperplasia after vascular injury in vivo.

INTERPRETATION

These results suggest that local delivery of Sema3A may act as a novel therapeutic option to prevent in-stent restenosis.

Baicalin inhibits proliferation and promotes apoptosis of vascular smooth muscle cells by regulating the MEG3/p53 pathway following treatment with ox‑LDL

Atherosclerosis (AS) is a systemic disease associated with lipid metabolic disorders and abnormal proliferation of smooth muscle cells. Baicalin is a flavonoid compound isolated from the dry roots of Scutellaria baicalensis Georgi and exerts anti-proliferative effects in various types of cells. However, the effect of baicalin on AS remains unclear. In the present study, serum samples were collected from patients with AS and an in vitro model of AS was established using oxidized low-density lipoprotein (ox-LDL)-treated human aorta vascular smooth muscle cells (HA-VSMCs). The siRNA transfection and overexpression efficiency of endogenous maternally expressed gene 3 (MEG3) and the expression level of MEG3 were analyzed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The effects of alterations in expression levels of MEG3 were assessed by MTT assay, bromodeoxyuridine incorporation assay, 5-ethynyl-2′-deoxyuridine staining, wound healing assay, immunofluorescence and western blotting in HA-VSMCs. qPCR indicated that the expression of MEG3 was reduced in serum samples from patients with AS and ox-LDL-treated HA-VSMCs, compared with serum samples from healthy patients and untreated HA-VSMCs, respectively. Further experiments indicated that ox-LDL-induced decrease of MEG3 expression was reversed by treatment with baicalin in a concentration-dependent manner. Following treatment with ox-LDL, decreased expression of MEG3 promoted proliferation and migration, and suppressed apoptosis in HA-VSMCs. Furthermore, treatment with baicalin reversed these effects on proliferation and apoptosis in ox-LDL-treated HA-VSMCs. The current study indicated that downregulated expression of MEG3 increased cell cycle-associated protein expression. However, treatment with baicalin inhibited the expression of cell-cycle associated proteins in HA-VSMCs with MEG3 knockdown. In addition, baicalin activated the p53 signaling pathway and promoted the expression and transport of p53 from the cytoplasm to nucleus following MEG3 knockdown in ox-LDL-treated HA-VSMCs. Baicalin inhibited proliferation and promoted apoptosis by regulating the expression of MEG3/p53, indicating that baicalin may serve a role in AS by activating the MEG3/p53 signaling pathway. The present study suggested a potential mechanism underlying the protective role of baicalin in the in vitro model of AS, and these results may be used to develop novel therapeutic approaches for the affected patients.

Estrogen receptor beta signaling inhibits PDGF induced human airway smooth muscle proliferation

Airway smooth muscle (ASM) cell hyperplasia driven by persistent inflammation is a hallmark feature of remodeling in asthma. Sex steroid signaling in the lungs is of considerable interest, given epidemiological data showing more asthma in pre-menopausal women and aging men. Our previous studies demonstrated that estrogen receptor (ER) expression increases in asthmatic human ASM; however, very limited data are available regarding differential roles of ERα vs. ERβ isoforms in human ASM cell proliferation. In this study, we evaluated the effect of selective ERα and ERβ modulators on platelet-derived growth factor (PDGF)-stimulated ASM proliferation and the mechanisms involved. Asthmatic and non-asthmatic primary human ASM cells were treated with PDGF, 17β-estradiol, ERα-agonist and/or ERβ-agonist and/or G-protein-coupled estrogen receptor 30 (GPR30/GPER) agonist and proliferation was measured using MTT and CyQuant assays followed by cell cycle analysis. Transfection of small interfering RNA (siRNA) ERα and ERβ significantly altered the human ASM proliferation. The specificity of siRNA transfection was confirmed by Western blot analysis. Gene and protein expression of cell cycle-related antigens (PCNA and Ki67) and C/EBP were measured by RT-PCR and Western analysis, along with cell signaling proteins. PDGF significantly increased ASM proliferation in non-asthmatic and asthmatic cells. Treatment with PPT showed no significant effect on PDGF-induced proliferation, whereas WAY interestingly suppressed proliferation via inhibition of ERK1/2, Akt, and p38 signaling. PDGF-induced gene expression of PCNA, Ki67 and C/EBP in human ASM was significantly lower in cells pre-treated with WAY. Furthermore, WAY also inhibited PDGF-activated PCNA, C/EBP, cyclin-D1, and cyclin-E. Overall, we demonstrate ER isoform-specific signaling in the context of ASM proliferation. Activation of ERβ can diminish remodeling in human ASM by inhibiting pro-proliferative signaling pathways, and may point to a novel perception for blunting airway remodeling.

SFRP5 serves a beneficial role in arterial aging by inhibiting the proliferation, migration and inflammation of smooth muscle cells

Secreted frizzled-related protein 5 (SFRP5) is one of the anti-inflammatory adipokines secreted from white adipose tissue. However, little is known about the effect of SFRP5 on the cardiovascular system. The aim of the present study was to determine the effect of SFRP5 on smooth muscle cell (SMC) proliferation, migration and inflammation. The plasma levels of SFRP5 were evaluated in a cohort‑based elderly population using ELISA, and the expression of SFRP5 in Sprague‑Dawley rat aortas was detected using immunohistochemistry. SMC proliferation and migration were evaluated in vitro using 5‑ethynyl‑2'‑deoxyuridine cell proliferation and wound‑healing assays, respectively, while reactive oxygen species (ROS) production and cell signaling were assessed using a 2',7'‑dichlorodihydrofluorescein diacetate assay and immunoblotting, respectively. The results revealed that plasma levels of SFRP5 were positively correlated with age in the elderly Chinese cohort. Similarly, aorta SFRP5 expression was significantly higher in 15‑month‑old rats compared with 6‑month‑old rats. In vitro, SFRP5 significantly inhibited rat aortic SMC proliferation and migration that were induced by platelet‑derived growth factor (PDGF)‑BB, as well as inhibiting ROS generation. Compared with the effect of PDGF‑BB on SMCs, SFRP5 at 100 and 200 ng/ml significantly decreased SMC proliferation by 31.5 and 34.8%, respectively (P<0.05). SFRP5 at 100 and 200 ng/ml also inhibited the migration of SMCs by 24.9 and 28.4%, respectively, when compared with the effects of PDGF‑BB. SFRP5 attenuated the PDGF‑BB‑induced expression of β‑catenin and proliferating cell nuclear antigen, while p38 phosphorylation was significantly attenuated. Together, the present results suggested that SFRP5 may inhibit SMC proliferation, migration and inflammation by suppressing the Wnt/β‑catenin and p38/mitogen‑activated protein kinase signaling pathways.

The Signaling Pathways Involved in the Antiatherosclerotic Effects Produced by Chinese Herbal Medicines

Cardiovascular diseases (CVDs) are considered to be the predominant cause of death in the world. Chinese herb medicines (CHMs) have been widely used for the treatment of CVDs in Asian countries for thousands of years. One reason of high efficacy of CHMs in treating CVDs is attributed to their inhibition in atherosclerosis (AS) development, a critical contributor to CVDs occurrence. Cumulative studies have demonstrated that CHMs alleviate atherogenesis via mediating pathophysiologic events involved in AS. However, there is deficiency in the summaries regarding antiatherogenic signal pathways regulated by CHMs. In this review, we focus on the signal cascades by which herb medicines and relevant extractives, derivatives, and patents improve proatherogenic processes including endothelium dysfunction, lipid accumulation, and inflammation. We mainly elaborate the CHMs-mediated signaling pathways in endothelial cells, macrophages, and vascular smooth muscle cells of each pathogenic event. Moreover, we briefly describe the other AS-related factors such as thrombosis, autophagy, immune response, and noncoding RNAs and effects of CHMs on them in the way of cascade regulation, which is helpful to further illustrate the molecular mechanisms of AS initiation and progression and discover newly effective agents for AS management.

MicroRNA-24 regulates vascular remodeling via inhibiting PDGF-BB pathway in diabetic rat model

PURPOSE

Hyperglycemia is the high risk factor of vascular remodeling induced by angioplasty, and neointimal hyperplasia is strongly implicated in the pathogenesis of vascular remodeling caused by carotid artery balloon injury. Studies have shown that MicroRNA 24 (miR-24) plays an important role in angiocardiopathy, However, the role of miR-24 is far from thorough research. In this study, we investigate whether up-regulation of miR-24 by using miR-24 recombinant adenovirus (Ad-miR-24-GFP) can inhibit PDGF-BB signaling pathway and attenuate vascular remodeling in the diabetic rat model.

METHODS

Male Sprague-Dawley rats (n = 60) were randomly divided into 5 groups and fed with high sugar and high fat diet (Sham, Saline, Scramble, Ad-miR-24 groups), or ordinary diet (Control group). The front four groups were treated with streptozotocin (STZ) four weeks later and the blood glucose level was closely monitored. After the successful establishment of diabetic rats, the external carotid artery was injured by pressuring balloon 1.5 after internal carotid artery ligation, then the blood vessels were harvested 14 days later and indexes were detected including the following: HE staining for the level of vascular intima thickness, immunohistochemical detection for PCNA and P27 to test the proliferative degree of vascular smooth muscle cells (VSMCs), qRT-PCR for the level of miR-24, RAS,PDGF-R, western blot for the protein levels of JNK1/2, p- JNK1/2, ERK1/2, p-ERK1/2, RAS, PDGF-R, AP-1,P27 and PCNA. Serological detection was conducted for TNF-α, IL-6, IL-8.

RESULTS

The delivery of Ad-miR-24 into balloon injury site has significantly increased the level of miR-24. Up-regulation of miR-24 could regulate vascular remodeling effectively, lower the level of inflammatory factors, inhibit the expression of mRNA and protein levels of JNK1/2, ERK1/2, RAS, PDGF-R, AP-1, P27, PCNA.

CONCLUSION

miR-24 can inhibit the expression of AP-1 via the inhibition of PDGF-BB signaling pathway, thus inhibit VSMCs proliferation and vascular remodeling.

Antitumor effects of baicalin on ovarian cancer cells through induction of cell apoptosis and inhibition of cell migration in vitro

Baicalin, an active flavone isolated from Scutellaria baicalensis Georgi, has been demonstrated to induce various beneficial biochemical effects such as anti‑inflammatory, anti‑viral, and antitumor effects. However, the antitumor mechanism of baicalin is not well understood. In the present study, baicalin was demonstrated to inhibit the viability and migration of a widely used ovarian cancer cell line, A2780, in a dose‑dependent manner. MTT assays revealed that cell viability significantly decreased in ovarian cancer cells treated with baicalin compared with untreated cells, without effect on normal ovarian cells. Flow cytometric analysis indicated that baicalin suppressed cell proliferation by inducing apoptosis. The underlying mechanisms involved were indicated to be downregulation of the anti‑apoptotic protein B‑cell lymphoma 2 apoptosis regulator and activation of caspase‑3 and ‑9. In addition, wound healing and transwell assays revealed that cell migratory potential and expression of matrix metallopeptidase (MMP)‑2 and MMP‑9 were significantly inhibited when cells were exposed to baicalin, compared with untreated cells. The present study therefore suggested that baicalin has the potential to be used in novel anti‑cancer therapeutic formulations for treatment of ovarian cancer.

Baicalein inhibits tumor progression by inhibiting tumor cell growth and tumor angiogenesis

Baicalein, a herbal medicine, is a natural flavonoid isolated from the roots of Scutellaria baicalensis Georgi. It is known for its anticancer, anti-inflammatory and neuroprotective properties. Despite these well-known properties, it is not yet clear what effect baicalein has on tumor progression. Therefore, in the present study, we used B16F10 cells, Lewis lung carcinoma (LLC) cells, and human umbilical vein endothelial cells (HUVECs) to investigate the effect of baicalein on cell proliferation and viability, migration and tube formation in vitro. In addition, an experimental animal model was used to observe the growth rate and metastasis of tumors and tumor vessel formation in vivo. Our results showed that baicalein decreased the proliferation and migration and induced tumor cell death via caspase-3 activation in the B16F10 and LLC cells, and strongly inhibited tube formation and cell migration in HUVECs. Furthermore, mouse models showed that baicalein reduced the tumor volume and greatly reduced the tumor growth rate in the early stages of tumor progression, and the baicalein-treated groups had significantly reduced expression of CD31 (endothelial cell marker) and α-SMA (mural cell marker) in the tumors, indicating that baicalein inhibits tumor angiogenesis by disrupting tumor vasculature development. Comparison of the lymph node and lung samples collected from the baicalein-treated group, and the untreated group showed that baicalein reduced metastasis of the tumor to these tissues. In summary, baicalein reduced tumor progression and metastasis, directly induced tumor cell death, and inhibited tumor angiogenesis. Our results strongly demonstrate that baicalein is a potential chemotherapeutic agent.

Baicalin attenuates chronic hypoxia-induced pulmonary hypertension via adenosine A2A receptor-induced SDF-1/CXCR4/PI3K/AKT signaling

Background

Baicalin, an important flavonoid in Scutellaria baicalensis Georgi extracts, exerts a variety of pharmacological effects. In this study, we explored the effects of baicalin on chronic hypoxia-induced pulmonary arterial hypertension (PAH) and investigated the mechanism underlying these effects. Moreover, we examined whether the inflammatory response was mediated by the A_2A receptor (A_2AR) and stromal cell-derived factor-1 (SDF-1)/C-X-C chemokine receptor type 4 (CXCR4)-induced phosphatidyl inositol-3-kinase (PI3K) signaling in vivo.

Methods

We established a hypoxia-induced pulmonary hypertension (HPH) mouse model by subjecting wild-type (WT) and A_2AR knockout (A_2AR^−/−) animals to chronic hypoxia, and we examined the effects of a 4-week treatment with baicalin or the A_2AR agonist CGS21680 in these animals. Invasive hemodynamic parameters, the right ventricular hypertrophy index, pulmonary congestion, the pulmonary arterial remodeling index, blood gas parameters, A_2AR expression, and the expression of SDF-1/CXCR4/PI3K/protein kinase B (PKB; AKT) signaling components were measured.

Results

Compared with WT mice, A_2AR^−/− mice exhibited increased right ventricular systolic pressure (RVSP), right ventricle-to-left ventricle plus septum [RV/(LV + S)] ratio, RV weight-to-body weight (RV/BW) ratio, and lung wet weight-to-body weight (Lung/BW) ratio in the absence of an altered mean carotid arterial pressure (mCAP). These changes were accompanied by increases in pulmonary artery wall area and thickness and reductions in arterial oxygen pressure (P_aO₂) and hydrogen ion concentration (pH). In the HPH model, A_2AR^−/− mice displayed increased CXCR4, SDF-1, phospho-PI3K, and phospho-AKT expression compared with WT mice. Treating WT and A_2AR^−/− HPH mice with baicalin or CGS21680 attenuated the hypoxia-induced increases in RVSP, RV/(LV + S) and Lung/BW, as well as pulmonary arterial remodeling. Additionally, baicalin or CGS21680 alone could reverse the hypoxia-induced increases in CXCR4, SDF-1, phospho-PI3K, and phospho-AKT expression. Moreover, baicalin improved the hypoxemia induced by 4 weeks of hypoxia. Finally, we found that A_2AR levels in WT lung tissue were enhanced by hypoxia and that baicalin up-regulated A_2AR expression in WT hypoxic mice.

Conclusions

Baicalin exerts protective effects against clinical HPH, which are partly mediated through enhanced A_2AR activity and down-regulated SDF-1/CXCR4-induced PI3K/AKT signaling. Therefore, the A_2AR may be a promising target for baicalin in treating HPH.

Baicalin attenuates monocrotaline-induced pulmonary hypertension through bone morphogenetic protein signaling pathway

Baicalin, a flavonoid compound extracted from roots of Scutellaria baicalensis Georgi (huang qin), it has been shown to effectively attenuates pulmonary hypertension (PH), however, the potential mechanism remains unexplored. In this study, we investigated the potential mechanism of baicalin on monocrotaline (MCT)-induced PH in rats. The results showed that baicalin attenuated lung damage in PH rat model through inhibiting the pulmonary arterial smooth muscle cell proliferation and induction of cells apoptosis. Furthermore, we demonstrated that baicalin inhibition the expression of nuclear factor-κB (NF-κB) p65 and bone morphogenetic protein (BMP) antagonists gremlin-1, but increased the expression of inhibitor of NF-κB (I-κBα), BMPR2, BMP-4, BMP-9 and Smad1/5/8. Additionally, baicalin suppression endothelial-to-mesenchymal transition in PH lung tissue. Collectively, we confirmed that baicalin via inhibition of NF-κB signaling to further activation of BMP signaling to have a therapeutic effect on PH and providing a promising therapeutic strategy for PH.

Therapeutic potentials of baicalin and its aglycone, baicalein against inflammatory disorders

The flavonoids, baicalin (5,6-dihydroxy-2-phenyl-4H-1-benzopyran-4-one-7-O-d-β-glucuronic acid) 1 and its aglycone, baicalein 2 are found in edible medicinal plants, Scutellaria baicalensis Georgi and Oroxylum indicum (L.) Kurz in abundant quantities. The antioxidant and anti-inflammatory effects of these flavonoids have been demonstrated in various disease models, including diabetes, cardiovascular diseases, inflammatory bowel diseases, gout and rheumatoid arthritis, asthma, neurodegenerative-, liver- and kidney diseases, encephalomyelitis, and carcinogenesis. These flavonoids have almost no toxicity to human normal epithelial, peripheral and myeloid cells. Their antioxidant and anti-inflammatory activities are largely due to their abilities to scavenge the reactive oxygen species (ROS) and improvement of antioxidant status by attenuating the activity of NF-κB and suppressing the expression of several inflammatory cytokines and chemokines including monocyte chemotactic protein-1 (MCP-1), nitric oxide synthase, cyclooxygenases, lipoxygenases, cellular adhesion molecules, tumor necrosis factor and interleukins. In this review, we summarize the antioxidant and anti-inflammatory effects of baicalin and baicalein with molecular mechanisms for their chemopreventive and chemotherapeutic applications in the treatment of inflammatory-related diseases.

ERK Signaling Pathway Plays a Key Role in Baicalin Protection Against Acetaminophen-Induced Liver Injury

Acetaminophen (APAP) overdose causes hepatocytes necrosis and acute liver failure. Baicalin (BA), a major flavonoid of Scutellariae radix, has potent hepatoprotective properties in traditional medicine. In the present study, we investigated the protective effects of BA on a APAP-induced liver injury in a mouse model. The mice received an intraperitoneal hepatotoxic dose of APAP (300[Formula: see text]mg/kg) and after 30[Formula: see text]min, were treated with BA at concentrations of 0, 15, 30, or 60[Formula: see text]mg/kg. After 16[Formula: see text]h of treatment, the mice were sacrificed for further analysis. APAP administration significantly elevated the serum alanine transferase (ALT) enzyme levels and hepatic myeloperoxidase (MPO) activity when compared with control animals. Baicalin treatment significantly attenuated the elevation of liver ALT levels, as well as hepatic MPO activity in a dose- dependent manner (15–60[Formula: see text]mg/kg) in APAP-treated mice. The strongest beneficial effects of BA were seen at a dose of 30[Formula: see text]mg/kg. BA treatment at 30[Formula: see text]mg/kg after APAP overdose reduced elevated hepatic cytokine (TNF-[Formula: see text] and IL-6) levels, and macrophage recruitment around the area of hepatotoxicity in immunohistochemical staining. Significantly, BA treatment can also decrease hepatic phosphorylated extracellular signal-regulated kinase (ERK) expression, which is induced by APAP overdose. Our data suggests that baicalin treatment can effectively attenuate APAP-induced liver injury by down-regulating the ERK signaling pathway and its downstream effectors of inflammatory responses. These results support that baicalin is a potential hepatoprotective agent.

α-Iso-Cubebene Inhibits PDGF-Induced Vascular Smooth Muscle Cell Proliferation by Suppressing Osteopontin Expression

α-Iso-cubebene (ICB) is a dibenzocyclooctadiene lignin contained in Schisandra chinensis (SC), a well-known medicinal herb that ameliorates cardiovascular symptoms. Thus, we examined the effect of ICB on vascular smooth muscle cell (VSMC) proliferation, a key feature of diverse vascular diseases. When VSMCs primary cultured from rat thoracic aorta were stimulated with PDGF (1-10 ng/ml), cell proliferation and osteopontin (OPN) expression were concomitantly up-regulated, but these effects were attenuated when cells were treated with MPIIIB10, a neutralizing monoclonal antibody for OPN. In aortic tissues exposed to PDGF, sprouting VSMC numbers increased, which was attenuated in tissues from OPN-deficient mice. Furthermore, VSMC proliferation and OPN expression induced by PDGF were attenuated dose-dependently by ICB (10 or 30 μg/ml). Reporter assays conducted using OPN promoter-luciferase constructs showed that the promoter region 538-234 bp of the transcription start site was responsible for transcriptional activity enhancement by PDGF, which was significantly inhibited by ICB. Putative binding sites for AP-1 and C/EBPβ in the indicated promoter region were suggested by TF Search, and increased binding of AP-1 and C/EBPβ in PDGF-treated VSMCs was demonstrated using a ChIP assay. The increased bindings of AP-1 and C/EBPβ into OPN promoter were attenuated by ICB. Moreover, the PDGF-induced expression of OPN was markedly attenuated in VSMCs transfected with siRNA for AP-1 and C/EBPβ. These results indicate that ICB inhibit VSMC proliferation by inhibiting the AP-1 and C/EBPβ signaling pathways and thus downregulating OPN expression.

SM22α inhibits lamellipodium formation and migration via Ras-Arp2/3 signaling in synthetic VSMCs

We previously demonstrated that smooth muscle (SM) 22α promotes the migration activity in contractile vascular smooth muscle cells (VSMCs). Based on the varied functions exhibited by SM22α in different VSMC phenotypes, we investigated the effect of SM22α on VSMC migration under pathological conditions. The results demonstrated that SM22α overexpression in synthetic VSMCs inhibited platelet-derived growth factor (PDGF)-BB-induced cell lamellipodium formation and migration, which was different from its action in contractile cells. The results indicated two distinct mechanisms underlying inhibition of lamellipodium formation by SM22α, increased actin dynamic stability and decreased Ras activity via interference with interactions between Ras and guanine nucleotide exchange factor. The former inhibited actin cytoskeleton rearrangement in the cell cortex, while the latter significantly disrupted actin nucleation activation of the Arp2/3 complex. Baicalin, a herb-derived flavonoid compound, inhibited VSMC migration via upregulation of SM22α expression in vitro and in vivo. These data suggest that SM22α regulates lamellipodium formation and cell migration in a phenotype-dependent manner in VSMCs, which may be a new therapeutic target for vascular lesion formation.

Inhibitory effect of NBL1 on PDGF-BB-induced human PASMC proliferation through blockade of PDGFβ-p38MAPK pathway

Pulmonary artery remodelling is a key feature in the pathological progress of pulmonary arterial hypertension (PAH). Moreover, excessive proliferation of pulmonary arterial smooth muscle cells (PASMCs) plays a critical role in the pathogenesis of pulmonary artery remodelling. Neuroblastoma suppressor of tumorigenicity 1 (NBL1) has been previously shown to induce growth inhibition in tumour cells. However, the effect of NBL1 in the regulation of human PASMC proliferation remains unclear. In cultured human PASMCs, we observed a dose-dependent inhibitory effect of NBL1 on platelet derived growth factor (PDGF)-BB-induced cell growth, DNA synthesis and proliferating cell nuclear antigen (PCNA) expression, as measured by MTS assay, 5-ethynil-2-deoxyuridine (EdU) analysis and western blots respectively. We also detected the expression and activities of cell-cycle positive regulators (cyclin D1, cyclin E, CDK2, CDK4 and CDK6) and negative regulators (p21 and p27) in human PASMCs by western blots and co-immuoprecipitation (IP). Our results show that NBL1-induced growth suppression is associated with the decreased activity of cyclin D1–CDK4 and the decreased phosphorylation of p27 in PDGF-BB-treated human PASMCs. By western blots using the phosphor-specific antibodies, we further demonstrated that NBL1 induced growth suppression is mediated by blockade of the up-stream PDGF-receptor β (PDGFRβ)-p38 mitogen-activated protein kinase (MAPK). In conclusion, our results suggest that NBL1 could inhibit PDGF-BB-induced human PASMC proliferation, and the underlying mechanism is associated with the decreased cyclin D1–CDK4 activity and up-regulated p27 by decreasing the phosphorylation of p27 via blockade of PDGFRβ-p38MAPK signal cascade. Our findings may provide a potential therapeutic target for PAH.

Hydrogen sulfide promotes cell proliferation of oral cancer through activation of the COX2/AKT/ERK1/2 axis

Hydrogen sulfide, the third gaseous transmitter, is one of the main causes of halitosis in the oral cavity. It is generally considered as playing a deleterious role in many oral diseases including oral cancer. However, the regulatory mechanisms involved in the effects of hydrogen sulfide on oral cancer growth remain largely unknown. In the present study, we investigated the underlying mechanisms through CCK-8 assay, EdU incorporation, real-time PCR, western blot and pathway blockade assays. Our results showed that hydrogen sulfide promoted oral cancer cell proliferation through activation of the COX2, AKT and ERK1/2 pathways in a dose-dependent manner. Blocking any of the three above pathways inhibited hydrogen sulfide-induced oral cancer cell proliferation. Meanwhile, blockade of COX2 by niflumic acid downregulated NaHS-induced p-ERK and p-AKT expression. Inactivation of the AKT pathway by GSK690693 significantly decreased NaHS‑induced p-ERK1/2 expression, and inhibition of the ERK1/2 pathway by U0126 markedly increased NaHS-induced p-AKT expression. Either the AKT or ERK1/2 inhibitor did not significantly alter the COX2 expression level. Our data revealed, for the first time, that hydrogen sulfide promotes oral cancer cell proliferation through activation of the COX2/AKT/ERK1/2 axis, suggesting new potential targets to eliminate the effect of hydrogen sulfide on the development of oral cancer.

Prevention of vascular smooth muscle cell proliferation and injury-induced neointimal hyperplasia by CREB-mediated p21 induction: An insight from a plant polyphenol

Cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/cAMP response element (CRE)-binding protein (CREB) signaling cascade negatively regulates platelet-derived growth factor BB (PDGF-BB)-induced smooth muscle cell (SMC) proliferation, which is a critical event in the initiation and development of restenosis and atherosclerotic lesions. Salvianolic acid A (SAA) is one of the most abundant polyphenols extracted from salvia. The aim of this study is to investigate whether SAA exerts an action on PDGF-BB-induced proliferation via cAMP/PKA/CREB mechanism. SAA blunts PDGF-BB-induced human umbilical artery smooth muscle cell (hUASMC) proliferation via p21 induction, as evidenced by its increased mRNA and protein expression levels. The SAA-induced upregulation of p21 involves the cAMP/PKA signaling pathway; a cAMP analog mimicked the effects of SAA and a specific cAMP/PKA inhibitor opposed these effects. SAA also activated CREB, including phosphorylation at Ser133, and induced its nuclear translocation. Deletion and mutational analysis of p21 promoters, co-immunoprecipitation, and western blot analysis showed that CRE is essential for SAA-induced p21 protein expression. Transfection of dominant-negative CREB (mutated Ser133) plasmids into hUASMCs attenuated SAA-stimulated p21 expression. SAA upregulated p21 expression and activated CREB in the neointima of balloon-injured arteries in vivo. Our results indicate that SAA promotes p21 expression in SMCs through the cAMP/PKA/CREB signaling cascade in vitro and prevents injury-induced neointimal hyperplasia.