Magnobovatol inhibits smooth muscle cell migration by suppressing PDGF-Rβ phosphorylation and inhibiting matrix metalloproteinase-2 expression

The extract of concentrated growth factor enhances osteogenic activity of osteoblast through PI3K/AKT pathway and promotes bone regeneration in vivo

BACKGROUND

Concentrated growth factor (CGF) is a third-generation platelet concentrate product; the major source of growth factors in CGF is its extract; however, there are few studies on the overall effects of the extract of CGF (CGF-e). The aim of this study was to investigate the effect and mechanism of CGF-e on MC3T3-E1 cells in vitro and to explore the effect of combination of CGF-e and bone collagen (Bio-Oss Collagen, Geistlich, Switzerland) for bone formation in cranial defect model of rats in vivo.

METHODS

The cell proliferation, ALP activity, mineral deposition, osteogenic-related gene, and protein expression were evaluated in vitro; the newly formed bone was evaluated by histological and immunohistochemical analysis through critical-sized cranial defect rat model in vivo.

RESULTS

The cell proliferation, ALP activity, mineral deposition, osteogenic-related gene, and protein expression of CGF-e group were significantly increased compared with the control group. In addition, there was significantly more newly formed bone in the CGF-e + bone collagen group, compared to the blank control group and bone collagen only group.

CONCLUSIONS

CGF-e activated the PI3K/AKT signaling pathway to enhance osteogenic differentiation and mineralization of MC3T3-E1 cells and promoted the bone formation of rat cranial defect model.

Glossogyne tenuifolia Attenuates Proliferation and Migration of Vascular Smooth Muscle Cells

The proliferation and migration of vascular smooth muscle cells (VSMCs) are essential in the pathogenesis of various vascular diseases, such as atherosclerosis and restenosis. Among the mediators of VSMC during atherosclerosis development, platelet-derived growth factor (PDGF)-BB is a potent mitogen for VSMCs and greatly contributes to the intimal accumulation of VSMCs. Glossogyne tenuifolia (GT, Xiang-Ru) is a traditional antipyretic and hepatoprotective herb from Penghu Island, Taiwan. This study evaluated the inhibitory effect of GT ethanol extract (GTE) and GT water extract (GTW) on proliferative and migratory activities in PDGF-BB-induced VSMCs. The experimental results demonstrated that GTE significantly inhibited the PDGF-BB-stimulated VSMC proliferation and migration, as shown by MTT, wound healing, and Boyden chamber assays. GTE was found to have a much more potent inhibitory activity than GTW. Based on the Western blot analysis, GTE significantly blocked the PDGF-BB-induced phosphorylation of NF-κB and mitogen-activated protein kinase (MAPK) pathways, including extracellular signal-regulated kinase (ERK), p38, and JNK, in VSMCs. In addition, GTE retarded the PDGF-BB-mediated migration through the suppression of matrix metalloproteinase (MMP)-2 and MMP-9 expression in VSMCs. Three main ingredients of GT-chlorogenic acid, luteolin-7-glucoside, and luteolin-all showed significant anti-proliferative effects on PDGF-BB-induced VSMCs. As a whole, our findings indicated that GTE has the potential to be a therapeutic agent to prevent or treat restenosis or atherosclerosis.

Heat shock protein 90 inhibitor AUY922 attenuates platelet-derived growth factor-BB-induced migration and proliferation of vascular smooth muscle cells

Luminespib (AUY922), a heat shock proteins 90 inhibitor, has anti-neoplastic and antitumor effects. However, it is not clear whether AUY922 affects events in vascular diseases. We investigated the effects of AUY922 on the platelet-derived growth factor (PDGF)-BB-stimulated proliferation and migration of vascular smooth muscle cells (VSMC). VSMC viability was detected using the XTT (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) reagent. To detect the attenuating effects of AUY922 on PDGF-BB-induced VSMCs migration in vitro, we performed the Boyden chamber and scratch wound healing assays. To identify AUY922-mediated changes in the signaling pathway, the phosphorylation of protein kinase B (Akt) and extracellular signal-regulated kinase (ERK) 1/2 was analyzed by immunoblotting. The inhibitory effects of AUY922 on migration and proliferation ex vivo were tested using an aortic ring assay. AUY922 was not cytotoxic at concentrations up to 5 nM. PDGF-BB-induced VSMC proliferation, migration, and sprout outgrowth were significantly decreased by AUY922 in a dose-dependent manner. AUY922 significantly reduced the PDGF-BB-stimulated phosphorylation of Akt and ERK1/2. Furthermore, PD98059 (a selective ERK1/2 inhibitor) and LY294002 (a selective Akt inhibitor) decreased VSMC migration and proliferation by inhibiting phosphorylation of Akt and ERK1/2. Greater attenuation of PDGF-BB-induced cell viability and migration was observed upon treatment with PD98059 or LY294002 in combination with AUY922. AUY922 showed anti-proliferation and anti-migration effects towards PDGF-BBinduced VSMCs by regulating the phosphorylation of ERK1/2 and Akt. Thus, AUY922 is a candidate for the treatment of atherosclerosis and restenosis.

Lignans and Neolignans: Plant secondary metabolites as a reservoir of biologically active substances

Lignans and neolignans are plant secondary metabolites derived from the oxidative coupling of phenylpropanoids. Biological activity of these phenolic compounds ranges from antioxidant, antitumor (terminaloside P, IC₅₀ = 10 nM), anti-inflammatory, anti-neurodegenerative (schibitubin B, IC₅₀ = 3.2 nM) and antiviral (patentiflorin A, IC₅₀ = 14-23 nM) to antimicrobial. In addition, it was observed that several members of this group, namely enterolactone and its biochemical precursors also known as phytoestrogens, possess important protective properties. Most of these lignans and neolignans are presented in reasonable amounts in one's diet and thus the protection they provide against the colon and breast cancer, to name a few, is even more important to note. Similarly, neuroprotective properties were observed (schisanwilsonin G, IC₅₀ = 3.2 nM) These structural motives also serve as an important starting point in the development of anticancer drugs. Presumably the most famous members of this family, etoposide and teniposide, synthetic derivatives of podophyllotoxin, are used in the clinical treatment of lymphocytic leukemia, certain brain tumors, and lung tumors already for nearly 20 years. This review describes 413 lignans and neolignans which have been isolated between 2016 and mid-2018 being reported in more than 300 peer-reviewed articles. It covers their source, structure elucidation, and bioactivity. Within the review, the structure-based overview of compounds as well as the bioactivity-based overview of compounds are described.

A review of the phytochemistry and pharmacological activities of Magnoliae officinalis cortex

ETHNOPHARMACOLOGICAL RELEVANCE

Magnoliae Officinalis Cortex (the dried bark of Magnolia officinalis), a widely used traditional Chinese medicine, is also known as 'Houpo' (Chinese: ). Magnoliae Officinalis Cortex has a wide range of pharmacological effects and has been used to treat conditions such as abdominal distention, vomiting, diarrhea, food accumulation, Qi stagnation, constipation, phlegm and fluid retention and cough resulting from asthma.

AIMS OF THE REVIEW

The present paper reviews advances in research relating to the botany, ethnopharmacology, phytochemistry, pharmacology and toxicology of Magnoliae Officinalis Cortex. Prospects for future investigation and application of this herb are also discussed.

MATERIALS AND METHODS

Information on Magnoliae Officinalis Cortex was obtained from published materials, including ancient and modern books; PhD and MSc dissertations; monographs on medicinal plants; the pharmacopoeia of different countries and electronic databases, such as SCI finder, PubMed, Web of Science, ACS, Science Direct, Wiley, Springer, Taylor, AGRIS, Europe PMC, EBSCO host, CNKI, WanFang DATA, J-STAGE and Google Scholar.

RESULTS

More than 200 chemical compounds have been isolated from Magnoliae Officinalis Cortex, including lignans, phenylethanoid glycosides, phenolic glycosides, alkaloids, steroids and essential oils. The plant has been reported to have pharmacological effects on the digestive system, nervous system and cardiovascular and cerebrovascular systems, as well as antibacterial, anti-tumour, analgesic, anti-inflammatory and anti-oxidative effects.

CONCLUSIONS

Magnoliae Officinalis Cortex is an essential traditional Chinese medicine with pharmacological activities that mainly affect the digestive system, nervous system and cardiovascular and cerebrovascular systems. This review summarises its botany, ethnopharmacology, phytochemistry, pharmacology and toxicology. These information suggest that we should focus on the development of new drugs related to Magnoliae Officinalis Cortex, including specific constituents, so that Magnoliae Officinalis Cortex can exert greater therapeutic potential. Meanwhile, it is important to pay attention to the rational use of Magnolia resources, avoiding over-harvesting which could lead to lack of resources. We should also pursue research on Magnolia substitutes and develop resources such as Magnoliae Officinalis Flos and Magnolia Leaf.

PDGF‑BB promotes the differentiation and proliferation of MC3T3‑E1 cells through the Src/JAK2 signaling pathway

Platelet-derived growth factor-BB (PDGF-BB) serves a critical function in human osteoblast differentiation and proliferation. Src and Janus kinase 2 (JAK2) are involved in these processes. In our previous study, it was identified that Src could promote the phosphorylation of JAK2. However, it has yet to be determined whether the Src/JAK2 signaling pathway affects PDGF-BB-mediated osteoblast differentiation and proliferation. In the present study, western blotting, polymerase chain reaction, alizarin red staining, alkaline phosphatase and Cell Counting kit-8 were employed to explore these questions. Firstly, it was demonstrated that PDGF-BB activates the Src/JAK2 signaling pathway in MC3T3-E1 cells in a time-dependent manner. Furthermore, it was demonstrated that PDGF-BB expression promoted MC3T3-E1 cell differentiation and proliferation; this process was suppressed by AG1295, SU6656 and AG490, which are inhibitors of PDGFR-β, Src and JAK2, respectively. SU6656 downregulated the activity of Src and JAK2, while AG490 only downregulated JAK2 activity. Therefore, it was concluded that Src is upstream of JAK2. PDGF-BB also upregulated the expression of osteogenesis-associated genes, and the formation of mineral nodules. However, these effects were markedly inhibited by treatment with SU6656. This indicated that PDGF-BB promoted MC3T3-E1 cell differentiation and proliferation by activating the Src/JAK2 signaling pathway. These results suggested that PDGF-BB may have potential applications in the treatment of osteoporosis and bone fractures.

Rubiarbonone C inhibits platelet-derived growth factor-induced proliferation and migration of vascular smooth muscle cells through the focal adhesion kinase, MAPK and STAT3 Tyr705 signalling pathways

BACKGROUND AND PURPOSE

The proliferation and migration of vascular smooth muscle cells (VSMCs) induced by platelet-derived growth factor (PDGF) are important steps in cardiovascular diseases, including neointimal lesion formation, myocardial infarction and atherosclerosis. Here, we evaluated the rubiarbonone C-mediated signalling pathways that regulate PDGF-induced VSMC proliferation and migration.

EXPERIMENTAL APPROACH

Cell proliferation and migration were measured in cells treated with rubiarbonone C followed by PDGF BB using the MTT assay, [³ H]-thymidine incorporation, flow cytometry and wound-healing migration assay, MMP gelatin zymography, a fluorescence assay for F-actin. Western blotting of molecules including MAPK, focal adhesion kinase (FAK) and STAT3 and an immunofluorescence assay using anti-PCNA and -STAT3 antibodies were performed to evaluate rubiarbonone C signalling pathway(s). The medial thickness of the carotid artery was evaluated using a mouse carotid ligation model.

KEY RESULTS

Rubiarbonone C inhibited PDGF-induced VSMC proliferation and migration and diminished the ligation-induced increase in medial thickness of the carotid artery. In PDGF-stimulated VSMCs rubiarbonone C decreased the following: (i) levels of cyclin-dependent kinases, cyclins, PCNA and hyperphosphorylated retinoblastoma protein; (ii) levels and activity of MMP2 and MMP9; (iii) activation of MAPK; (iv) F-actin reorganization, by reducing FAK activation; (v) activation of STAT3.

CONCLUSIONS AND IMPLICATIONS

These findings suggest that rubiarbonone C inhibits the proliferation and migration of VSMCs by inhibiting the FAK, MAPK and STAT3 signalling pathways. Therefore, rubiarbonone C could be a good candidate for the treatment of cardiovascular disease.

Chebulinic acid inhibits smooth muscle cell migration by suppressing PDGF-Rβ phosphorylation and inhibiting matrix metalloproteinase-2 expression

Excessive migration of vascular smooth muscle cells (VSMCs) after vascular injury contributes to the development of occlusive vascular disease. Inhibition of VSMC migration is a validated therapeutic modality for occlusive vascular diseases, such as atherosclerosis and restenosis. We investigated the inhibitory effect of chebulinic acid (CBA) on cell migration and matrix metalloproteinase (MMP)-2 activation in platelet-derived growth factor (PDGF)-BB-induced mouse and human VSMCs. CBA significantly inhibited PDGF-BB-induced migration in mouse and human VSMCs, without inducing cell death. Additionally, CBA significantly blocked PDGF-BB-induced phosphorylation of the PDGF receptor (PDGF-R), Akt, and extracellular signal-regulated kinase (ERK)1/2 by inhibiting the activation of the PDGF-BB signalling pathway. In both mouse and human VSMCs, CBA inhibited PDGF-induced MMP-2 mRNA and protein expression as well as the proteolytic activity of MMP-2. Moreover, CBA suppressed sprout outgrowth formation of VSMCs from endothelium-removed aortic rings as well as neointima formation following rat carotid balloon injury. Taken together, our findings indicated that CBA inhibits VSMC migration by decreasing MMP-2 expression through PDGF-R and the ERK1/2 and Akt pathways. Our data may improve the understanding of the antiatherogenic effects of CBA in VSMCs.

Shear Stress in Autophagy and Its Possible Mechanisms in the Process of Atherosclerosis

Autophagy can eliminate harmful components and maintain cellular homeostasis in response to a series of extracellular insults in eukaryotes. More and more studies show that autophagy plays vital roles in the development of atherosclerosis. Atherosclerosis is a multifactorial disease and shear stress acts as a key role in its process. Understanding the role of shear stress in autophagy may offer insight into atherosclerosis therapies, especially emerging targeted therapy. In this article, we retrospect related studies to summarize the present comprehension of the association between autophagy and atherosclerosis onset and progression.