Cardamonin inhibits angiotensin II-induced vascular smooth muscle cell proliferation and migration by downregulating p38 MAPK, Akt, and ERK phosphorylation

Zingiberaceae in Cardiovascular Health: A review of adipokine modulation and endothelial protection via adipocyte-endothelial crosstalk mechanism

PURPOSE OF THE REVIEW

Although adipose tissue controls metabolism and protects vital organs, its importance to general health is being highlighted by the rise in type 2 diabetes and cardiovascular disease. Adipokines produced by adipose cells are essential regulators of metabolism, glucose homeostasis, and inflammatory response. It also protects vascular endothelial cells for its potential implications for cardiovascular protection. Understanding its intricate involvement in adipose tissue-endothelial communication is critical in developing targeted therapeutics to treat cardiovascular conditions linked with obesity and metabolic dysregulation. Spices from the Zingiberaceae family, such as cardamom, turmeric, and ginger, have anti-inflammatory and anti-oxidant properties that help reduce oxidative stress, vascular dysfunction, and adipocyte-endothelial crosstalk which are all linked to the etiology of CVD. Comprehensive molecular insights into how they modulate adipokine signalling, inflammatory pathways, and ROS-induced adipocyte-vascular interactions remain unexplored, demanding additional translational and clinical validation. With an emphasis on patients with obesity and metabolic dysregulation, the investigation aims to elucidate the mechanisms by which the spice as whole/bioactive constituents of the Zingiberaceae family may provide protection against CVD by integrating previous studies.

RECENT FINDINGS

Current research continues to support the use of spices from the Zingiberaceae family, such as ginger, turmeric, cardamom, and pepper, as potential therapeutic agents for addressing metabolic complications like obesity, type II diabetes, and CVDs. These natural remedies may modulate adipocyte-endothelial crosstalk and inflammation by modulating important signalling pathways such as AMPK, AKT, PPAR, and NF-κB..

CONCLUSION

This review provides a complete summary of existing knowledge, opening the way for future research and prospective therapeutic applications of Zingiberaceae spices in cardiovascular health management.

The multifaceted anti-atherosclerotic properties of herbal flavonoids: A comprehensive review

Atherosclerosis (AS) is a major etiological factor underpinning a spectrum of cardiovascular diseases, leading to cerebral infarction, coronary artery disease, and peripheral vascular disease. The chronic progression of AS, spanning from initial plaque formation to the occurrence of acute cardiovascular events, underscores the complexity of AS and the challenges it presents in terms of treatment. Currently, the clinical management of AS relies predominantly on statins and proprotein convertase subtilisin/kexin type 9 inhibitors, which primarily aim to reduce low-density lipoprotein levels and have demonstrated some therapeutic efficacy. Nevertheless, due to their potential side effects, there is a pressing need to actively investigate alternative treatment approaches. Researches on natural compounds derived from herbal medicines, such as flavonoids, hold significant promise in combating AS by regulating lipid metabolism, reducing oxidative stress and inflammation, inhibiting the proliferation of vascular smooth muscle cells, modulating autophagy and additional pathways. Various targets participate in these physiological processes, encompassing acyl-CoA: cholesterol acyltransferase (ACAT), ATP citrate lyase (ACLY), nuclear factor erythroid 2-related factor 2 (Nrf2), krüppel-like factor 2 (KLF2), NOD-like receptor protein 3 (NLRP3), transcription factor EB (TFEB) and so on. This comprehensive review endeavors to synthesize and analyse the most recent findings on herbal flavonoids, shedding light on their anti-atherosclerotic potential and the underlying protective mechanisms and related-targets, which might pave the way for the development of novel drug candidates or the optimization of flavonoid-based therapies.

Exendin-4, a glucagon-like peptide-1 receptor agonist, regulates ductus arteriosus by vasodilation and anti-remodeling through the PKA pathway

The mechanisms of ductus arteriosus (DA) closure involve vasoconstriction and vascular remodeling. Previous findings indicate that the glucagon-like peptide-1 receptor agonist (GLP-1RA) exhibits antihypertensive and anti-remodeling effects in the pulmonary circulation. However, its role in the DA remains unknown. This study aimed to investigate whether exendin-4 (Ex-4), a GLP-1RA, can regulate DA patency and elucidate its mechanisms. After confirming the presence of GLP-1R in neonatal rat DA tissue in vivo, the effects of Ex-4 on DA patency in neonatal rats were sequentially examined. Two hours after birth, we observed spontaneous closure of the DA in control rats. In contrast, Ex-4 prevented the closure of DA, accompanied by reduced intimal thickening. Ex-4 attenuated oxygen-induced vasoconstriction in isolated DA rings ex vivo. This effect was diminished in the presence of H89, a PKA inhibitor. In vitro, Ex-4 inhibited platelet-derived growth factor (PDGF)-BB-induced proliferation and migration of DA smooth muscle cells. Additionally, Ex-4 inhibited PDGF-BB-induced reactive oxygen species (ROS) production, calcium mobilization, and signal transduction of MAPK and Akt pathways. Furthermore, Ex-4 preserved the nuclear expression of Nrf2 attenuated by PDGF-BB. Similarly, all these in vitro effects of Ex-4 were blunted by H89. In conclusion, Ex-4 maintains postnatal DA patency through vasodilatation and anti-remodeling via the PKA pathway. The GLP-1R/PKA pathway emerges as a promising target of DA patency in clinical management.

Hexahydrocurcumin mitigates angiotensin II-induced proliferation, migration, and inflammation in vascular smooth muscle cells

The proliferation and migration of vascular smooth muscle cells (VSMCs) play vital roles in the pathogenesis of atherosclerosis and hypertension. It has been proposed and verified that hexahydrocurcumin (HHC), a metabolite form of curcumin, has cardiovascular protective effects. This study examined the effect of HHC on angiotensin II (Ang II)-induced proliferation, migration, and inflammation in rat aortic VSMCs and explored the molecular mechanisms related to the processes. The results showed that HHC significantly suppressed Ang II-induced proliferation, migration, and inflammation in VSMCs. HHC inhibited Ang II-induction of the increase in cyclin D1 and decrease in p21 expression in VSMCs. Moreover, HHC attenuated the generation of reactive oxygen species (ROS), and the expression of nuclear factor kappa B (NF-κB), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and matrix metalloproteinases-9 (MMP9) in Ang II-induced VSMCs. The proliferation, migration, inflammation, and ROS production were also inhibited by GKT137831 (NADPH oxidase, NOX1/4 inhibitor) and the combination of HHC and GKT137831. In addition, HHC restored the Ang-II inhibited expression of peroxisome proliferator-activated receptor-γ (PPAR-γ) and peroxisome proliferator activated receptor-γ coactivator-1α (PGC-1α). These findings indicate that HHC may play a protective role in Ang II-promoted proliferation, migration, and inflammation by suppressing NADPH oxidase mediated ROS generation and elevating PPAR-γ and PGC-1α expression. See also Figure 1(Fig. 1).

Inhibitors of dimerized translationally controlled tumor protein, a histamine releasing factor, may serve as anti-allergic drug candidates

It has been established that translationally controlled tumor protein (TCTP), also called histamine releasing factor (HRF), exhibits cytokine-like activities associated with initiation of allergic responses only after forming dimers (dTCTP). Agents that inhibit dTCTP by preventing its dimerization or otherwise block its function, also block development of allergic reactions, thereby serving as potential drugs to treat allergic diseases. Several lines of evidence have proven that peptides and antibodies that specifically inhibit the interactions between dTCTP and either its putative receptor or immunoglobulins exhibit significant in vivo efficacy as potential anti-inflammatory agents in murine models of allergic inflammatory diseases. This review highlights the development of several inhibitors targeting dTCTP and discusses how they affect the pathophysiologic processes of allergic and inflammatory diseases in several animal models and offers new perspectives on anti-allergic drug discovery.

The Neuroprotective Effects and Therapeutic Potential of the Chalcone Cardamonin for Alzheimer's Disease

Neurodegenerative diseases (ND) include a wide range of conditions that result from progressive damage to the neurons. Alzheimer's disease (AD) is one of the most common NDs, and neuroinflammation and oxidative stress (OS) are the major factors in the development and progression of the disease. Many naturally occurring phytochemical compounds exhibit antioxidant and anti-inflammatory activities with potential neuroprotective effects. Several plant species, including Alpinia katsumadai and Alpinia conchigera, contain cardamonin (CD). CD (2',4'-dihydroxy-6'methoxychalcone) has many therapeutic properties, including anticancer, anti-inflammatory, antioxidant, antiviral, and antibiotic activities. CD is a potent compound that can reduce OS and modulate the inflammatory processes that play a significant part in developing neurodegenerative diseases. CD has been shown to modulate a variety of signaling molecules involved in the development and progression of ND, including transcription factors (NF-kB and STAT3), cytokines (TNF-α, IL-1, and IL-6), enzymes (COX-2, MMP-9, and ALDH1), and other proteins and genes (Bcl-2, XIAP, and cyclin D1). Additionally, CD effectively modulates miRNA levels and autophagy-related CD-protective mechanisms against neurodegeneration. In summary, this review provides mechanistic insights into CD's ability to modify multiple oxidative stress-antioxidant system pathways, Nrf2, and neuroinflammation. Additionally, it points to the possible therapeutic potential and preventive utilization of CD in neurodegenerative diseases, most specifically AD.

Cardamonin inhibits LPS-induced inflammatory responses and prevents acute lung injury by targeting myeloid differentiation factor 2

BACKGROUND

Acute lung injury (ALI) is a systemic inflammatory process, which has no pharmacological therapy in clinic. Accumulating evidence has demonstrated that natural compounds from herbs have potent anti-inflammatory efficacy in several disease models, which could be the potential candidates for the treatment of ALI.

HYPOTHESIS/PURPOSE

Anti-inflammatory screening from natural product bank may provide new anti-inflammatory compounds for therapeutic target discovery and ALI treatment.

METHODS

165 natural compounds were screened for their anti-inflammatory activity in LPS-stimulated macrophages. PCR array, SPR and ELISA were used to determine the potential target of the most active compound, Cardamonin (CAR). The pharmacological effect of CAR was further evaluated in both LPS-stimulated macrophages and ALI mice model.

RESULTS

Out of the screened 165 compounds, CAR significantly inhibited LPS-induced inflammatory cytokine secretion in macrophages. We further showed that CAR significantly inhibited NF-κB and JNK signaling activation, and thereby inflammatory cytokine production via directly interacting with MD2 in vitro. In vivo, our data show that CAR treatment inhibited LPS-induced lung damage, systemic inflammatory cytokine production, and reduced macrophage infiltration in the lungs, accompanied with reduced TLR4/MD2 complex in lung tissues, Treatment with CAR also dose-dependently increased survival in the septic mice induced by DH5α bacterial infection.

CONCLUSION

We demonstrate that a natural product, CAR, attenuates LPS-induced lung injury and sepsis by inhibiting inflammation via interacting with MD2, leading to the inactivation of the TLR4/MD2-MyD88-MAPK/NF-κB pathway.

Anticancer Effect of Heparin-Taurocholate Conjugate on Orthotopically Induced Exocrine and Endocrine Pancreatic Cancer

Simple Summary

Pancreatic cancer has a less than 9% 5-year survival rate among patients because it is very difficult to detect and diagnose early. Combinatorial chemotherapy with surgery or radiotherapy is a potential remedy to treat pancreatic cancer. However, these strategies still have side effects such as hair loss, skin soreness and fatigue. To overcome these side effects, angiogenesis inhibitors such as sunitinib are used to deliver targeted blood vessels around tumor tissues, including pancreatic cancer tumors. It is still controversial whether antiangiogenesis therapy is sufficient to treat pancreatic cancer. So far, many scientists have not been focused on the tumor types of pancreatic cancer when they have developed antipancreatic cancer medication. Here, we used heparin–taurocholate (LHT) as an anticancer drug to treat pancreatic cancer through inhibition of angiogenic growth factors. In this study, we examined the anticancer efficacy of LHT on various types of pancreatic cancer in an orthotopic model.

Abstract

Pancreatic cancers are classified based on where they occur, and are grouped into those derived from exocrine and those derived from neuroendocrine tumors, thereby experiencing different anticancer effects under medication. Therefore, it is necessary to develop anticancer drugs that can inhibit both types. To this end, we developed a heparin–taurocholate conjugate, i.e., LHT, to suppress tumor growth via its antiangiogenic activity. Here, we conducted a study to determine the anticancer efficacy of LHT on pancreatic ductal adenocarcinoma (PDAC) and pancreatic neuroendocrine tumor (PNET), in an orthotopic animal model. LHT reduced not only proliferation of cancer cells, but also attenuated the production of VEGF through ERK dephosphorylation. LHT effectively reduced the migration, invasion and tube formation of endothelial cells via dephosphorylation of VEGFR, ERK1/2, and FAK protein. Especially, these effects of LHT were much stronger on PNET (RINm cells) than PDAC (PANC1 and MIA PaCa-2 cells). Eventually, LHT reduced ~50% of the tumor weights and tumor volumes of all three cancer cells in the orthotopic model, via antiproliferation of cancer cells and antiangiogenesis of endothelial cells. Interestingly, LHT had a more dominant effect in the PNET-induced tumor model than in PDAC in vivo. Collectively, these findings demonstrated that LHT could be a potential antipancreatic cancer medication, regardless of pancreatic cancer types.

Allergic Inflammation Caused by Dimerized Translationally Controlled Tumor Protein is Attenuated by Cardamonin

We demonstrated in our previous reports that dimeric form of translationally controlled tumor protein (dTCTP) initiates a variety of allergic phenomena. In the present study, we examined whether and how dTCTP's role in allergic inflammation can be modulated or negated. The possible potential of cardamonin as an anti-allergic agent was assessed by ELISA using BEAS-2B cells and OVA-challenged allergic mouse model. The interaction between cardamonin and dTCTP was confirmed by SPR assay. Cardamonin was found to reduce the secretion of IL-8 caused by dTCTP in BEAS-2B cells by interacting with dTCTP. This interaction between dTCTP and cardamonin was confirmed through kinetic analysis (K_D = 4.72 ± 0.07 μM). Also, cardamonin reduced the migration of various inflammatory cells in the bronchoalveolar lavage fluid (BALF), inhibited OVA specific IgE secretion and bronchial remodeling. In addition, cardamonin was observed to have an anti-allergic response by inhibiting the activity of NF-κB. Cardamonin exerts anti-allergic anti-inflammatory effect by inhibiting dTCTP, suggesting that it may be useful in the therapy of allergic diseases.

Angiotensin (1-7) Inhibits Ang II-mediated ERK1/2 Activation by Stimulating MKP-1 Activation in Vascular Smooth Muscle Cells

The renin–angiotensin system (RAS) exerts profound physiological effects on blood pressure regulation and fluid homeostasis, mainly by modulating renal, cardiovascular, and central nervous systems. Angiotensin (Ang)-(1-7), an end-product of RAS, is recognized by its cardiovascular protective properties through stimulation of the Mas receptor, including vasodilation, anti-inflammatory, and antihypertensive actions, and consequently, counter-regulating the well-known Ang II-elicited actions. The overall hypothesis of this study is that Ang-(1-7) inhibits Ang II-induced ERK1/2 activation in vascular smooth muscle cells (VSMCs), via regulation of mitogen-activated protein phosphatase-1 (MKP-1) activity. Aortas from male Wistar rats were incubated with Ang-(1-7) or vehicle. Concentration-response curves to Ang II were performed in endothelium-denuded aortas, in the presence or absence of ERK1/2 (PD98059) inhibitor or Mas receptor (A-779) antagonist. Expression of proteins was assessed by western blot, and immunohistochemistry was conducted in VSMCs. Ang-(1-7) incubation decreased Ang II-induced contractile response in aortas, and this effect was not observed in the presence of PD98059 or A-779. Stimulation of VSMCs with Ang-(1-7) prevented Ang II-induced ERK1/2 phosphorylation, but not C-Raf-activation. Furthermore, Ang II decreased MKP-1 phosphorylation in VSMCs. Interestingly, simultaneous incubation of Ang-(1-7) with Ang II favored MKP-1 phosphorylation, negatively modulating ERK1/2 activation in VSMCs. The results suggest that Ang-(1-7) counter-regulates actions evoked by Ang II overproduction, as observed in cardiovascular diseases, mainly by modulating MKP-1 activity. This evidence suggests that the role of Ang-(1-7) in MKP-1-regulation represents a target for new therapeutic development.

The CX3CL1/CX3CR1 axis is upregulated in chronic kidney disease and contributes to angiotensin II-induced migration of vascular smooth muscle cells

BACKGROUND

The role of the chemokine axis, CX3CL1/CX3CR1, in the development of cardiovascular diseases has been widely speculated. Angiotensin II (Ang II) is a pivotal factor promoting cardiovascular complications in patients with chronic kidney disease (CKD). Whether there is a link between the two in CKD remains unclear.

METHODS

The uremic mice were treated with losartan for 8 weeks, and the expression of aortic CX3CL1/CX3CR1 was detected. Cultured mouse aortic vascular smooth muscle cells (VSMCs) were stimulated with Ang II, and then CX3CR1 expression was assessed by western blot. After the targeted disruption of CX3CR1 by transfection with siRNA, the migration of VSMCs was detected by transwell assay. Finally, both the activation of Akt pathway and the expression of IL-6 were detected by western blot.

RESULTS

Losartan treatment reduced the upregulation of aortic CX3CL1/CX3CR1 expression in uremic mice. In vitro, Ang II significantly upregulated CX3CR1 expression in VSMCs. Targeted disruption of CX3CR1 attenuated Ang II-induced migration of VSMCs. In addition, the use of CX3CR1-siRNA suppressed Akt phosphorylation and IL-6 production in VSMCs stimulated by Ang II.

CONCLUSIONS

The aortic CX3CL1/CX3CR1 is upregulated by Ang II in CKD, and it contributes to Ang II-induced migration of VSMCs in vitro.

Cardamonin protects against doxorubicin-induced cardiotoxicity in mice by restraining oxidative stress and inflammation associated with Nrf2 signaling

The clinical application of doxorubicin (DOX) for cancer treatment is limited due to its cardiotoxicity. However, the basic pathophysiological molecular mechanisms underlying DOX-induced cardiomyopathy have not yet been completely clarified, and the disease-specific therapeutic strategies are lacking. The aim of the present study was to investigate the potential cardioprotective effect of cardamonin (CAR), a flavone found in Alpinia plant, on DOX-induced cardiotoxicity in a mouse model. At first, in DOX-treated mouse cardiomyocytes, CAR showed significantly cytoprotective effects through elevating nuclear factor erythroid-2 related factor 2 (Nrf2) signaling, and reducing the degradation of Nrf2. This process then improved the anti-oxidant system, as evidenced by the up-regulated expression levels of haem oxygenase-1 (HO1), NAD(P)H:quinone oxidoreductase 1 (NQO1), glutamate-cysteine ligase modifier subunit (GCLM), superoxide dismutase (SOD), glutathione (GSH) and catalase (CAT). In contrast, DOX-induced increases in malondialdehyde (MDA) and reactive oxygen species (ROS) were highly inhibited by CAR treatments. Additionally, DOX-induced apoptosis and inflammatory response in cardiomyocytes were diminished by CAR through reducing the Caspase-3 and nuclear factor-κB (NF-κB) signaling pathways, respectively. Then, in the DOX-induced animal model with cardiotoxicity, we confirmed that through improving Nrf2 signaling, CAR markedly suppressed oxidative stress, apoptosis and inflammatory response in hearts of mice, improving cardiac function eventually. Together, our findings demonstrated that CAR activated Nrf2-related cytoprotective system, and protected the heart from oxidative damage, apoptosis and inflammatory injury, suggesting that CAR might be a potential therapeutic strategy in the prevention of DOX-associated myocardiopathy.

[Daxx overexpression inhibits AngⅡ-induced proliferation and migration in vascular smooth muscle cells]

OBJECTIVE

To construct a recombinant lentiviral expression vector pCDH-Daxx-EGFP to investigate the effect of Daxx on the proliferation of vascular smooth muscle cells (VSMCs).

METHODS

The recombinant lentiviral expression vector pCDHDaxx-EGFP was constructed using PCR-based accurate synthesis method. After identification by sequencing and enzyme digestion, the recombinant lentiviral vector was contransfected into 293T cells with lentivirus packaging vector. The recombinant lentivirus particles were collected and purified to infect VSMCs, whose expression of Daxx was detected with Western boltting. The cells infected with the empty vector pCDH-EGFP or pCDH-Daxx-EGFP were incubated in serum-free medium or in the presence of angiotensin Ⅱ (AngⅡ). The cell viability was determined with MTT assay, and the cell cycle changes were analyzed with flow cytometry. The cell migration ability was assessed using a scratch wound healing assay. The expression of p-Akt protein in the cells was detected using Western blotting.

RESULTS

Double enzyme digestion and sequencing confirmed successful construction of the recombinant plasmid. Compared with the cells infected with the empty vector, the cells infected with pCDH-Daxx-EGFP exhibited significantly increased expressions of Daxx protein (P < 0.05). AngⅡ treatment of the cells infected with the pCDH-Daxx-EGFP, as compared with the cells infected with the empty vector, significantly lowered the cell viability, S phase cell ratio and cell migration ability (P < 0.05), and significantly decreased the expression level of p-Akt protein (P < 0.05).

CONCLUSIONS

We successfully constructed the recombinant lentiviral vector pCDH-Daxx-EGFP and overexpressed Daxx in primary cultured VSMCs using this vector. Daxx overexpression can inhibit AngⅡ-induced proliferation and migration in VSMCs probably by regulating p-Akt protein.

Cortistatin exerts antiproliferation and antimigration effects in vascular smooth muscle cells stimulated by Ang II through suppressing ERK1/2, p38 MAPK, JNK and ERK5 signaling pathways

Background

Vascular remodeling, that contributes to cardiovascular diseases such as hypertension develops by anomalous proliferation and migration of vascular smooth muscle cells (VSMCs). Cortistatin (CST), a newly discovered biological peptide, has been acknowledged for its protective effects against cardiovascular diseases. Whether CST has an inhibitory regulation role in angiotensin II (Ang II)-induced proliferation and migration of VSMCs and what molecular mechanisms may participate in the CST inhibition process are still unknown.

Methods

VSMCs were divided into control group, Ang II (10^-7 M) group, Ang II + PD98059 (5×10^-5 M) group, Ang II + SB203580 (10^-5 M) group, Ang II + SP600125 (10^-5 M) group, Ang II + XMD17-109 (10^-6 M) group, Ang II + CST (10^-8 M) group and Ang II + CST (10^-7 M) group. Cell proliferation was detected by western blotting and cell counting kit-8 (CCK8) analysis. Migration of VSMCs was measured by Transwell assay.

Results

Compared with control group, Ang II upregulated the expression levels of proliferating cell nuclear antigen (PCNA) and osteopontin (OPN) and downregulated that of α-smooth muscle actin (α-SMA), increased the proliferation rate as shown by CCK8 and VSMC migration as shown by Transwell assay in cultured VSMCs of the Ang II group. Meanwhile, in Ang II-cultured VSMCs, we found activation of extracellular signal-regulated kinase (ERK) 1/2, p38 MAP kinase (p38 MAPK), c-Jun N-terminal kinase (JNK), and ERK5 pathways by western blotting at different time points. However, the proliferation and migration stimulated by Ang II were partly reversed by drug inhibitors of the four pathways, namely, PD98059, SB203580, SP600125 and XMD17-109. When Ang II-stimulated VSMCs were cultured with CST pretreatment, we found that proliferation and migration were greatly suppressed as well as that the ERK1/2, p38 MAPK, JNK and ERK5 pathways were deactivated by CST.

Conclusions

The accumulated data suggest that CST may play a protective role in Ang II-promoted proliferation and migration of VSMCs via inhibiting the mitogen-activated protein kinase (MAPK) family pathways, providing a new orientation of CST in protecting against cardiovascular diseases.

microRNA-21 regulates astrocytic reaction post-acute phase of spinal cord injury through modulating TGF-β signaling

Astrogliosis following spinal cord injury (SCI) was considered as a negative factor for neural regeneration. We found that miR-21 was significantly upregulated after SCI. So, we aim to determine whether miR-21 acts in a positive manner post SCI. In vitro, we measured the proliferation, apoptosis and cytokine secretion of primary cultured astrocytes after modulating the expression of miR-21 by western blot, RT-PCR and immunofluorescence. In vivo, we performed a modified Allen's weight drop model. Manipulation of the miR-21 expression level was achieved by interfering with antagomir and agomir. Clinic score was evaluated and recorded every day. Then, western blot, immunohistochemistry, TUNEL assay and ELISA were performed to detect pathological and functional alterations. Our results demonstrate that miR-21 can modulate the secretion, proliferation and apoptosis of astrocytes to promote recovery after SCI both in vivo and in vitro. These effects are likely mediated through transforming growth factor beta mediated targeting of the PI3K/Akt/mTOR pathway. These data suggest that miR-21 can regulate astrocytic function, then promote the functional recovery after SCI. We therefore highlight the positive effects of miR-21 after SCI.

CX3CL1/CX3CR1 Axis Contributes to Angiotensin II-Induced Vascular Smooth Muscle Cell Proliferation and Inflammatory Cytokine Production

Angiotensin II (Ang II) dysregulation has been determined in many diseases. The CX3CL1/CX3CR1 axis, which has a key role in cardiovascular diseases, is involved in the proliferation and inflammatory cytokine production of vascular smooth muscle cells (VSMCs). In this study, we aim to explore whether Ang II has a role in the expression of CX3CL1/CX3CR1, thus contributing to the proliferation and pro-inflammatory status of VSMCs. Cultured mouse aortic VSMCs were stimulated with 100 nmol/L of Ang II, and the expression of CX3CR1 was assessed by western blot. The results demonstrated that Ang II significantly up-regulated CX3CR1 expression in VSMCs and induced the production of reactive oxygen species (ROS) and the phosphorylation of p38 MAPK. Inhibitors of NADPH oxidase, ROS, and AT1 receptor significantly reduced Ang II-induced CX3CR1 expression. Targeted disruption of CX3CR1 by transfection with siRNA significantly attenuated Ang II-induced VSMC proliferation as well as down-regulated the expression of proliferating cell nuclear antigen (PCNA). Furthermore, CX3CR1-siRNA suppressed the effect of Ang II on stimulating Akt phosphorylation. Besides, the use of CX3CR1-siRNA decreased inflammatory cytokine production induced by Ang II treatment. Our results indicate that Ang II up-regulates CX3CR1 expression in VSMCs via NADPH oxidase/ROS/p38 MAPK pathway and that CX3CL1/CX3CR1 axis contributes to the proliferative and pro-inflammatory effects of Ang II in VSMCs.

Klotho Inhibits Proliferation and Migration of Angiotensin II-Induced Vascular Smooth Muscle Cells (VSMCs) by Modulating NF-κB p65, Akt, and Extracellular Signal Regulated Kinase (ERK) Signaling Activities

Background

It has been proven that phenotype shifting, from the contractile phenotype to the synthetic phenotype, of vascular smooth muscle cells (VSMCs), plays an important role in vascular diseases such as atherosclerosis, restenosis, and hypertension. Recently, accumulating evidence suggests that Klotho is associated with many cardiovascular diseases or damage. Through the estimation of the proliferation and migration of Ang II-induced VSMCs and the related intracellular signal transduction pathways, we researched the effects of Klotho on phenotype modulation in this study.

Material/Methods

A rat vascular smooth muscle cell line was grown in vitro with or without Ang II or Klotho, and cell proliferation and migration were evaluated.

Results

The dose-dependent inhibition of Ang II-induced proliferation and migration by Klotho was shown in VSMCs. The phenotype modulation was inhibited by Klotho co-treatment; this co-treatment promoted the expression of contractile phenotype marker proteins, including SM22α, and also the proliferation phenotype marker protein PCNA compared with Ang II alone, which was suppressed, and activated VSMCs. Furthermore, by reducing the expression of G0/G1-specific regulatory proteins such as cyclin D1, cyclin-dependent kinase (CDK) 4, cyclin E, and CDK2, cell cycle arrest was induced by Klotho at G0/G1 phase. Although Ang II strongly stimulated NF-κB, p65, Akt, and ERK phosphorylation, these activation events were diminished by co-treatment with Ang II and Klotho.

Conclusions

Phenotype modulation of Ang II-induced VSMCs and stimulation of the NF-κB, p65, Akt, and ERK signaling pathways were inhibited by Klotho, which suggests that Klotho may play an important role in the phenotype modulation of VSMCs.

Docosahexaenoic acid suppresses angiotensin II-induced A7r5 vascular smooth muscle cell proliferation and migration under pulsatile pressure stress

Elevated mechanical stress applied to vascular walls is well known to modulate vascular remodeling and plays a part in the pathogenesis of atherosclerosis. On the other hand, docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid, has been shown to protect against several types of cardiovascular diseases including atherosclerosis and hypertension. The aim of this study was to clarify the effect of pulsatile pressure stress and DHA on angiotensin II-induced proliferation and migration in A7r5 vascular smooth muscle cells (VSMCs). Pulsatile pressure of between 80 and 160 mmHg was repeatedly applied to VSMCs at a frequency of 4 cycles per min using an apparatus that we developed. Cell proliferation and migration were evaluated using a live cell movie analyzer. Application of pulsatile pressure stress for 24 h significantly increased cell proliferation. Angiotensin II also significantly increased cell proliferation in the presence or absence of pressure stress. DHA significantly inhibited angiotensin II-induced cell proliferation regardless of the pressure load. Angiotensin II significantly induced cell migration regardless of the pulsatile pressure load. Pulsatile pressure stress alone slightly, but not significantly, induced cell migration. DHA inhibited angiotensin II-induced VSMC proliferation and migration under abnormal pressure conditions. Pressure stress tended to induce extracellular signal-regulated kinase (ERK) phosphorylation in the absence of angiotensin II, whereas it significantly induced ERK phosphorylation in the presence of angiotensin II. However, the pressure-induced ERK phosphorylation was not observed in the DHA-treated VSMCs. Our findings may contribute to the understanding of the beneficial effect of DHA on various cardiovascular disorders.

AAV-Mediated angiotensin 1-7 overexpression inhibits tumor growth of lung cancer in vitro and in vivo

Ang-(1-7) inhibits lung cancer cell growth both in vitro and in vivo. However, the molecular mechanism of action is unclear and also the rapid degradation of Ang-(1-7) in vivo limits its clinical application. Here, we have demonstrated that Ang- (1-7) inhibits lung cancer cell growth by interrupting pre-replicative complex assembly and restrains epithelial-mesenchymal transition via Cdc6 inhibition. Furthermore, we constructed a mutant adeno-associated viral vector AAV8 (Y733F) that produced stable and high efficient Ang-(1-7) expression in a xenograft tumor model. The results show that AAV8-mediated Ang-(1-7) over-expression can remarkably suppress tumor growth in vivo by down-regulating Cdc6 and anti-angiogenesis. Ang-(1-7) over-expression via the AAV8 method may be a promising strategy for lung cancer treatment.

Gene expression profiles and signaling mechanisms in α2B-adrenoceptor-evoked proliferation of vascular smooth muscle cells

BACKGROUND

α2-adrenoceptors are important regulators of vascular tone and blood pressure. Regulation of cell proliferation is a less well investigated consequence of α2-adrenoceptor activation. We have previously shown that α2B-adrenoceptor activation stimulates proliferation of vascular smooth muscle cells (VSMCs). This may be important for blood vessel development and plasticity and for the pathology and therapeutics of cardiovascular disorders. The underlying cellular mechanisms have remained mostly unknown. This study explored pathways of regulation of gene expression and intracellular signaling related to α2B-adrenoceptor-evoked VSMC proliferation.

RESULTS

The cellular mechanisms and signaling pathways of α2B-adrenoceptor-evoked proliferation of VSMCs are complex and include redundancy. Functional enrichment analysis and pathway analysis identified differentially expressed genes associated with α2B-adrenoceptor-regulated VSMC proliferation. They included the upregulated genes Egr1, F3, Ptgs2 and Serpine1 and the downregulated genes Cx3cl1, Cav1, Rhoa, Nppb and Prrx1. The most highly upregulated gene, Lypd8, represents a novel finding in the VSMC context. Inhibitor library screening and kinase activity profiling were applied to identify kinases in the involved signaling pathways. Putative upstream kinases identified by two different screens included PKC, Raf-1, Src, the MAP kinases p38 and JNK and the receptor tyrosine kinases EGFR and HGF/HGFR. As a novel finding, the Src family kinase Lyn was also identified as a putative upstream kinase.

CONCLUSIONS

α2B-adrenoceptors may mediate their pro-proliferative effects in VSMCs by promoting the activity of bFGF and PDGF and the growth factor receptors EGFR, HGFR and VEGFR-1/2. The Src family kinase Lyn was also identified as a putative upstream kinase. Lyn is known to be expressed in VSMCs and has been identified as an important regulator of GPCR trafficking and GPCR effects on cell proliferation. Identified Ser/Thr kinases included several PKC isoforms and the β-adrenoceptor kinases 1 and 2. Cross-talk between the signaling mechanisms involved in α2B-adrenoceptor-evoked VSMC proliferation thus appears to involve PKC activation, subsequent changes in gene expression, transactivation of EGFR, and modulation of kinase activities and growth factor-mediated signaling. While many of the identified individual signals were relatively small in terms of effect size, many of them were validated by combining pathway analysis and our integrated screening approach.

IP-10/CXCR3 Axis Promotes the Proliferation of Vascular Smooth Muscle Cells through ERK1/2/CREB Signaling Pathway

Excessive proliferation of vascular smooth muscle cells is one of the main pathological processes leading to atherosclerosis and intimal hyperplasia after vascular interventional therapy. Our previous study has shown that interferon-γ inducible protein-10 contributes to the proliferation of vascular smooth muscle cell. However, the underlying mechanisms remain unclear. Extracellular signal-regulated kinase 1/2, serine/threonine kinase Akt, and cAMP response element binding protein are signaling pathways, which are considered to play important roles in the processes of vascular smooth muscle cell proliferation. Moreover, chemokine receptor 3 and Toll-like receptor 4 are potential receptors of inducible protein-10 in this process. In the present study, IP-10 was found to directly induce vascular smooth muscle cell proliferation, and exposure to inducible protein-10 activated extracellular signal-regulated kinase 1/2, serine/threonine kinase, and cAMP response element binding protein signaling. Inhibitor of extracellular signal-regulated kinase 1/2, rather than inhibitor of serine/threonine kinase, inhibited the phosphorylation of cAMP response element binding protein and reduced inducible protein-10-stimulated vascular smooth muscle cell proliferation. Knockdown of cAMP response element binding protein by siRNA inhibited inducible protein-10-induced vascular smooth muscle cell proliferation. Moreover, anti-CXCR3 IgG, instead of anti-Toll-like receptor 4 IgG, reduced inducible protein-10-induced vascular smooth muscle cell proliferation and inducible protein-10-stimulated extracellular signal-regulated kinase 1/2 and cAMP response element binding protein activation. Together, these results indicate that inducible protein-10 promotes vascular smooth muscle cell proliferation via chemokine receptor 3 and activation of extracellular signal-regulated kinase 1/2 inducible protein-10-induced vascular smooth muscle cell proliferation. These data provide important targets for future studies to modulate atherosclerosis and restenosis after vascular interventional therapy.

Microvesicles Derived from Inflammation-Challenged Endothelial Cells Modulate Vascular Smooth Muscle Cell Functions

Purpose: Microvesicles (MV) can modulate the function of recipient cells by transferring their contents. Our previous study highlighted that MV released from tumor necrosis factor-α (TNF-α) plus serum deprivation (SD)-stimulated endothelial progenitor cells, induce detrimental effects on endothelial cells. In this study, we investigated the potential effects of endothelial MV (EMV) on proliferation, migration, and apoptosis of human brain vascular smooth cells (HBVSMC).

Methods: EMV were prepared from human brain microvascular endothelial cells (HBMEC) cultured in a TNF-α plus SD medium. RNase-EMV were made by treating EMV with RNase A for RNA depletion. The proliferation, apoptosis and migration abilities of HBVSMC were determined after co-culture with EMV or RNase-EMV. The Mek1/2 inhibitor, PD0325901, was used for pathway analysis. Western blot was used for analyzing the proteins of Mek1/2, Erk1/2, phosphorylation Erk1/2, activated caspase-3 and Bcl-2. The level of miR-146a-5p was measured by qRT-PCR.

Results: (1) EMV significantly promoted the proliferation and migration of HBVSMC. The effects were accompanied by an increase in Mek1/2 and p-Erk1/2, which could be abolished by PD0325901; (2) EMV decreased the apoptotic rate of HBVSMC by approximately 35%, which was accompanied by cleaved caspase-3 down-regulation and Bcl-2 up-regulation; (3) EMV increased miR-146a-5p level in HBVSMC by about 2-folds; (4) RNase-treated EMV were less effective than EMV on HBVSMC activities and miR-146a-5p expression.

Conclusion: EMV generated under inflammation challenge can modulate HBVSMC function and fate via their carried RNA. This is associated with activation of theMek1/2/Erk1/2 pathway and caspase-3/Bcl-2 regulation, during which miR-146a-5p may play an important role. The data suggest that EMV derived from inflammation-challenged endothelial cells are detrimental to HBVSMC homeostatic functions, highlighting potential novel therapeutic targets for vascular diseases.

Icariin Attenuates High-cholesterol Diet Induced Atherosclerosis in Rats by Inhibition of Inflammatory Response and p38 MAPK Signaling Pathway

Icariin is a flavonoid isolated from the traditional Chinese herbal medicine Epimedium brevicornum Maxim and has been reported to be effective for the treatment of a variety of cardiovascular diseases. The aim of the present study was to investigate the effect and mechanism of icariin on atherosclerosis (AS) using a high-cholesterol diet (HCD)-induced rat model. Seventy male Wistar rats were divided into five groups: 20 in the control group, 20 in the AS group, 10 in the simvastatin group, 10 in the low-dose icariin group, and 10 in the high-dose icariin group. A HCD and vitamin D3 were administered to establish AS rat model. The five groups of rats received daily intragastric administration of normal saline, simvastatin, or icariin (30 mg/kg/d, 60 mg/kg/d) for 4 weeks. The levels of blood lipids, superoxide dismutase (SOD), and malonaldehyde (MDA) were measured. The mRNA levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α were analyzed by real-time RT-PCR, and the serum levels of IL-6 and TNF-α were measured using ELISA kit. In addition, the expression of phosphorylated p38 (p-p38) MAPK was detected by Western blot analysis. The results indicated that AS rat models were successfully constructed. In the AS group, the levels of blood lipids including total cholesterol (TC), triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C), and MDA were significantly increased, while high-density lipoprotein-cholesterol (HDL-C) and SOD were significantly decreased, compared with those in the control group. However, icariin succeeded in improving these biochemical parameters towards the normal values in the control group. In the simvastatin group and the icariin groups, the serum levels of IL-6 and TNF-α and the related tissue mRNA levels, as well as the expression of p-p38 MAPK, were markedly reduced compared with the AS group. In conclusion, the present study indicated that icariin inhibited the HCD-induced dyslipidemia in rats, the mechanisms may be associated with the anti-inflammation, anti-oxidative stress, and downregulation of p-p38 MAPK by icariin.

Influence of crocetin on high-cholesterol diet induced atherosclerosis in rats via anti-oxidant activity together with inhibition of inflammatory response and p38 MAPK signaling pathway

The present study aimed to investigate the effect and possible mechanism of action of crocetin on the high cholesterol diet (HCD) induced atherosclerosis rat. The Wistar rats were used in the current investigation. The rats were divided into following group, Group I: control, Group II: HCD induced AS, Group III: AS + crocetin (25 mg/kg), Group IV: AS + crocetin (50 mg/kg) and Group V: AS + Simvastatin, respectively. AS was induced in the rats using the vitamin D₃ and HCD. The rats received the pre-determined treatment for the 10 weeks. After the study period, the level of lipid profile, malonaldehyde (MDA) and superoxide dismutase (SOD) were also estimated. The proinflammatory cytokines viz., tumor necrosis factor (TNF)-α and interleukin (IL)-6 were scrutinized using the ELISA kits. We also estimated the expression of phosphorylated p38 (p-p38) MAPK using the Western blot techniques. The results revealed that the AS was successfully induced in the rats. The AS control group rats showed the modulated level of lipid profile, and decreased the level of the SOD and boost the level of the MDA as compared with the normal control. However, crocetin thrived in enhancing the lipid profile toward the standard value in the normal control group rats. The crocetin and simvastatin group rats significantly inhibited the expression of the p-p38 MAPK as compared to the AS group rats. In conclusion, the current investigation revealed that the crocetin reduced the HCD induced dyslipidemia in the Wistar rats, the possible mechanism of action may be connected to the antioxidative, down regulating of p-p38 MAPK and antiinflammatory effect by crocetin.

Angiotensin-(1-7) abrogates angiotensin II-induced proliferation, migration and inflammation in VSMCs through inactivation of ROS-mediated PI3K/Akt and MAPK/ERK signaling pathways

The proliferation, migration and inflammation of vascular smooth muscle cells (VSMCs) contribute to the pathogenesis and progression of several cardiovascular diseases such as atherosclerosis and hypertension. Angiotensin (Ang)-(1–7) and Ang II are identified to be involved in regulating cardiovascular activity. The present study is designed to determine the interaction between Ang-(1–7) and Ang II on VSMCs proliferation, migration and inflammation as well as their underlying mechanisms. We found that Ang-(1–7) significantly suppressed the positive effects of Ang II on VSMCs proliferation, migration and inflammation, as well as on induction of the phosphorylation of Akt and ERK1/2 and increase of superoxide anion level and NAD(P)H oxidase activity in VSMCs, whereas Ang-(1–7) alone had no significant effects. This inhibitory effects of Ang-(1–7) were abolished by Mas receptor antagonist A-779. In addition, Ang II type 1 (AT₁) receptor antagonist losartan, but not A-779, abolished Ang II induced VSMCs proliferation, migration and inflammation responses. Furthermore, superoxide anion scavenger N-acetyl-L-cysteine (NAC) or NAD(P)H oxidase inhibitor apocynin inhibited Ang II-induced activation of Akt and ERK1/2 signaling. These results indicate that Ang-(1–7) antagonizes the Ang II-induced VSMC proliferation, migration and inflammation through activation of Mas receptor and then suppression of ROS-dependent PI3K/Akt and MAPK/ERK signaling pathways.

Uric acid stimulates proliferative pathways in vascular smooth muscle cells through the activation of p38 MAPK, p44/42 MAPK and PDGFRβ

Hyperuricemia and angiotensin II (Ang II) may have a pathogenetic role in the development of hypertension and atherosclerosis as well as cardiovascular disease (CVD) and its prognosis. The purpose of this study was to investigate whether uric acid can induce proliferative pathways of vascular smooth muscle cell (VSMC) that are thought to be responsible for the development of CVD. The phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK), p44/42 mitogen-activated protein kinase (p44/42 MAPK) and platelet-derived growth factor receptor β (PDGFRβ) was measured by Elisa and Western blot techniques to determine the activation of proliferative pathways in primary cultured VSMCs from rat aorta. Results demonstrated that uric acid can stimulate p38 MAPK, p44/42 MAPK and PDGFRβ phosphorylation in a time- and concentration-dependent manner. Furthermore, treatment of VSMCs with the angiotensin II type I receptor (AT1R) inhibitor losartan suppressed p38 MAPK and p44/42 MAPK induction by uric acid. The stimulatory effect of uric acid on p38 MAPK was higher compared to that of Ang II. The results of this study show for the first time that uric acid-induced PDGFRβ phosphorylation plays a crucial role in the development of CVDs and that elevated uric acid levels could be a potential therapeutical target in CVD patients.

Paeoniflorin inhibits human pancreatic cancer cell apoptosis via suppression of MMP-9 and ERK signaling

Paeoniflorin exhibits anticancer, anti-inflammatory and antioxidation effects, as well as specific pharmacological effects on smooth muscle and the immune, cardiovascular and central nervous systems. The present study aimed to investigate the anticancer effects of paeoniflorin on pancreatic cancer cells and to elucidate the mechanisms by which these effects occur. In the present study, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assays were performed to assess cell viability and cell cytotoxicity of BXPC-3 human pancreatic cancer cells, respectively. Cellular apoptosis and caspase-3/9 activities were analyzed using an Annexin V-fluorescein isothiocyanate/propidium iodide Apoptosis Detection kit, a DAPI staining assay and colorimetric kits, respectively. Matrix metalloproteinase-9 (MMP-9) and extracellular signal-regulated kinases (ERK) protein expression in BXPC-3 cells were also investigated using gelatin zymography assays and western blot analysis, respectively. In the present study, paeoniflorin was found to inhibit the cell viability and increase cell cytotoxicity of BXPC-3 cells in a dose- and time-dependent manner. In addition, cellular apoptosis, as well as caspase-3 and -9 activity of BXPC-3 cells was increased following paeoniflorin treatment. Notably, paeoniflorin reduced MMP-9 and ERK protein expression in BXPC-3 cells. These results indicate that paeoniflorin exhibits a potential anticancer effect by enhancing human pancreatic cancer cell apoptosis via the suppression of MMP-9 and ERK signaling.

Systems-Pharmacology Dissection of Traditional Chinese Medicine Compound Saffron Formula Reveals Multi-scale Treatment Strategy for Cardiovascular Diseases

Cardiovascular diseases (CVDs) have been regarding as “the world’s first killer” of human beings in recent years owing to the striking morbidity and mortality, the involved molecular mechanisms are extremely complex and remain unclear. Traditional Chinese medicine (TCM) adheres to the aim of combating complex diseases from an integrative and holistic point of view, which has shown effectiveness in CVDs therapy. However, system-level understanding of such a mechanism of multi-scale treatment strategy for CVDs is still difficult. Here, we developed a system pharmacology approach with the purpose of revealing the underlying molecular mechanisms exemplified by a famous compound saffron formula (CSF) in treating CVDs. First, by systems ADME analysis combined with drug targeting process, 103 potential active components and their corresponding 219 direct targets were retrieved and some key interactions were further experimentally validated. Based on this, the network relationships among active components, targets and diseases were further built to uncover the pharmacological actions of the drug. Finally, a “CVDs pathway” consisted of several regulatory modules was incorporated to dissect the therapeutic effects of CSF in different pathological features-relevant biological processes. All this demonstrates CSF has multi-scale curative activity in regulating CVD-related biological processes, which provides a new potential way for modern medicine in the treatment of complex diseases.

Angiotensin-(1-7) Decreases Cell Growth and Angiogenesis of Human Nasopharyngeal Carcinoma Xenografts

Angiotensin-(1-7) [Ang-(1-7)] is an endogenous, heptapeptide hormone acting through the Mas receptor (MasR), with antiproliferative and antiangiogenic properties. Recent studies have shown that Ang-(1-7) has an antiproliferative action on lung adenocarcinoma cells and prostate cancer cells. In this study, we report that MasR levels were significantly upregulated in nasopharyngeal carcinoma (NPC) specimens and NPC cell lines. Viral vector-mediated expression of Ang-(1-7) dramatically suppressed NPC cell proliferation and migration in vitro. These effects were completely blocked by the specific Ang-(1-7) receptor antagonist A-779, suggesting that they are mediated by the Ang-(1-7) receptor Mas. In this study, Ang-(1-7) not only caused a significant reduction in the growth of human nasopharyngeal xenografts, but also markedly decreased vessel density, suggesting that the heptapeptide inhibits angiogenesis to reduce tumor size. Mechanistic investigations revealed that Ang-(1-7) inhibited the expression of the proangiogenic factors VEGF and PlGF. Taken together, the data suggest that upregulation of MasR could be used as a diagnostic marker of NPC and Ang-(1-7) may be a novel therapeutic agent for nasopharyngeal cancer therapy because it exerts significant antiangiogenic activity.

Cardamonin Regulates miR-21 Expression and Suppresses Angiogenesis Induced by Vascular Endothelial Growth Factor

Cardamonin has promising potential in cancer prevention and therapy by interacting with proteins and modifying the expressions and activities, including factors of cell survival, proliferation, and angiogenesis. In our precious study, we have demonstrated that cardamonin suppressed vascular endothelial growth factor- (VEGF-) induced angiogenesis as evaluated in the mouse aortic ring assay. It is also known that microRNAs (miRNAs) play important roles in angiogenesis. Herein, we hypothesized whether antiangiogenesis effect of cardamonin in human umbilical vein endothelial cells (HUVECs) triggered by VEGF was associated with miRNAs. We found that cardamonin reduced the miR-21 expression induced by VEGF in HUVECs. Treatment with miR-21 mimics abolished the effects of cardamonin on VEGF-induced cell proliferation, migration, and angiogenesis in HUVECs. However, treatment with miR-21 inhibitors presented the opposite effects, indicating the vital role of miR-21 in this process. Our study provides a new insight of the preliminary mechanism of anti-VEGF-induced angiogenesis by cardamonin in HUVECs.

MicroRNA-1298 is regulated by DNA methylation and affects vascular smooth muscle cell function by targeting connexin 43

AIMS

Growing evidence links microRNA to the process of peripheral vascular disease. Recently, we have found that microRNA-1298(miR-1298) is one of the most significantly down-regulated microRNAs in human arteries with arteriosclerosis obliterans (ASO) of the lower extremities. However, little is known regarding its role in the process of ASO. The present study aimed to investigate the expression, regulatory mechanisms, and functions of miR-1298 in the process of ASO.

METHODS AND RESULTS

Using quantitative reverse-transcription PCR and in situ hybridization assays, miR-1298 was observed predominantly expressed in the vascular smooth muscle cells (VSMCs) and was significantly down-regulated in ASO compared with normal arteries. Pyrosequencing analysis revealed that the miR-1298 DNA upstream of CpG sites were hypermethylated in ASO compared with normal arteries. Next, the luciferase reporter assay revealed that miR-1298 down-regulation is related with upstream DNA CpG site hypermethylation. Introducing a miR-1298 mimic into cultured VSMCs significantly attenuated cell proliferation and migration. Connexin 43 (Cx43) was validated to be a functional target of miR-1298 that was involved in the miR-1298-mediated cellular effects. Finally, lentivirus-mediated delivery of miR-1298 and its target Cx43 into a rat carotid balloon injury model indicated that re-overexpression of miR-1298 significantly decreased neointimal formation by targeting connexin 43.

CONCLUSION

Our data demonstrate a specific role of the upstream DNA methylation/miR-1298/Cx43 pathway in regulating VSMC function and suggest that modulation of miR-1298 levels may offer a novel therapeutic approach for ASO.

Activation of the D4 dopamine receptor attenuates proliferation and migration of vascular smooth muscle cells through downregulation of AT1a receptor expression

Angiotensin (Ang) II has an important role in the vascular smooth muscle cell (VSMC) proliferation and migration and subsequently in the development of vascular diseases, whereas dopamine has the opposite effect. Previous studies have shown an interaction between dopamine and AT(1) receptors in the kidney. The dopamine D(4) receptor is expressed in arteries and has an inhibitory effect on VSMC proliferation. We hypothesized that the D(4) receptor, through its interaction with the AT(1a) receptor, may have an inhibitory effect on Ang II-mediated VSMC proliferation and migration, which could have a pivotal role in hypertension-induced vascular remodeling. In the current study, we found that Ang II markedly induced the proliferation and migration of A10 cells, which was inhibited by the D(4) receptor agonist PD168077. The activation of the D(4) receptor by PD168077 inhibited AT(1a) receptor expression in a concentration- and time-dependent manner. These effects were attenuated by silencing the D(4) receptor with a D(4) receptor-targeting small interfering RNA. The D(4) receptor-mediated inhibition of AT(1) receptor function involved protein kinase A (PKA). The activation of the D(4) receptor by PD168077 increased PKA activity in A10 cells, and the presence of a PKA inhibitor (PKA inhibitor 14-22, 10(-7) mol l(-1) per 24 h) blocked the inhibitory effect of the D(4) receptor on AT(1) receptor expression and function. The inhibitory effect of the D(4) receptor on AT(1) receptor expression and function was preserved in VSMCs (primary culture) from spontaneously hypertensive rats relative to VSMCs from Wistar-Kyoto rats. In conclusion, our data provide insight into the regulatory role of the D(4) receptor on AT(1a) receptor expression and function in VSMCs and suggest that targeting the action of the D(4) receptor may represent an effective therapeutic approach for the treatment of cardiovascular diseases.

Ras ssDNA aptamer inhibits vascular smooth muscle cell proliferation and migration through MAPK and PI3K pathways

Proliferation and migration of vascular smooth muscle cells (VSMCs) mediated by Ras proteins are crucial in restenosis following percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG). In this study, a novel, single-stranded DNA (ssDNA) aptamer designated as Ras-a1 with high affinity and specificity to human Ras protein was isolated using systematic evolution of ligands by exponential enrichment. Ras-a1 was delivered into VSMCs by electroporation using one square waveform of 200 V for 20 msec. Proliferation of VSMCs was determined using a cell counting kit‑8 assay, which revealed the maximal inhibitory rate (40%) was obtained at 24 h after Ras-a1 transfection. The migration of VSMCs, determined using a Transwell assay, was significantly inhibited in Rasa1 cells in a time-dependent manner. To investigate the potential mechanisms of transfected Ras-a1 on the migration and proliferation of VSMCs, the phosphorylation of MEK1/2, ERK1/2, and Akt was determined using western blot analysis, which showed that a marked downregulation was observed in the phosphorylation of MEK1/2, ERK1/2, and Akt following the delivery of Ras-a1. This result demonstrated that Ras-a1 inhibits the proliferation and migration of VSMCs by inhibiting the phosphorylation of Ras and interrupting signal transduction in the Ras‑MEK1/2‑ERK1/2 and phosphoinositide-3 kinase/Akt pathways. The novel Ras protein-targeted ssDNA aptamer selected may be applicable for the prevention of restenosis after PCI and CABG.