Open Access

A spleen tyrosine kinase inhibitor attenuates the proliferation and migration of vascular smooth muscle cells

  • Hyang-Hee Seo1,
  • Sang Woo Kim2,
  • Chang Youn Lee3,
  • Kyu Hee Lim4,
  • Jiyun Lee1,
  • Eunhyun Choi2,
  • Soyeon Lim2,
  • Seahyoung Lee2Email author and
  • Ki-Chul Hwang2Email author
Biological Research201750:1

https://doi.org/10.1186/s40659-016-0106-3

Received: 19 September 2016

Accepted: 9 December 2016

Published: 18 January 2017

Abstract

Background

Pathologic vascular smooth muscle cell (VSMC) proliferation and migration after vascular injury promotes the development of occlusive vascular disease. Therefore, an effective chemical agent to suppress aberrant proliferation and migration of VSMCs can be a potential therapeutic modality for occlusive vascular disease such as atherosclerosis and restenosis. To find an anti-proliferative chemical agent for VSMCs, we screened an in-house small molecule library, and the selected small molecule was further validated for its anti-proliferative effect on VSMCs using multiple approaches, such as cell proliferation assays, wound healing assays, transwell migration assays, and ex vivo aortic ring assay.

Results

Among 43 initially screened small molecule inhibitors of kinases that have no known anti-proliferative effect on VSMCs, a spleen tyrosine kinase (Syk) inhibitor (BAY61-3606) showed significant anti-proliferative effect on VSMCs. Further experiments indicated that BAY61 attenuated the VSMC proliferation in both concentration- and time-dependent manner, and it also significantly suppressed the migration of VSMCs as assessed by both wound healing assays and transwell assays. Additionally, BAY61 suppressed the sprouting of VSMCs from endothelium-removed aortic rings.

Conclusion

The present study identified a Syk kinase inhibitor as a potent VSMC proliferation and migration inhibitor and warrants further studies to elucidate its underlying molecular mechanisms, such as its primary target, and to validate its in vivo efficacy as a therapeutic agent for restenosis and atherosclerosis.

Keywords

Syk kinase inhibitor BAY61-3606 VSMC Proliferation Migration

Background

Normal vascular smooth muscle cells (VSMCs) maintain a minimal proliferation rate and active contractility [1]. However, non-physiologic stimuli, such as excessive cytokines, shear stress, vascular injury, or inflammation, can promote the phenotypic switch of VSMCs from a contractile type to a synthetic phenotype [2, 3], leading to the development of occlusive vascular diseases [4, 5]. Such aberrant proliferation and migration of VSMCs limit the long-term efficacy of the clinical interventions such as angioplasty, stents, and coronary bypass [6]. To overcome this problem of excessive VSMC proliferation, advanced approaches (i.e., drug-eluting stents) have been tried and produced some promising results [7]. Nevertheless, the incidence of drug-eluding stent failure still remains at approximately 10%, [7, 8]. Furthermore, although different modalities, including calcium channel blockers, antiplatelet drugs, and angiotensin converting enzyme inhibitors, have been tried to control occlusive vascular disease, the results were not consistent [9]. Therefore, searching alternative means to control the aberrant proliferation and migration of VSMCs is still an important task for developing an optimized therapeutics to treat occlusive disease.

In the present study, we screened number of small molecule inhibitors of six major kinase subfamilies, to find an alternative therapeutic agent for suppressing VSMC proliferation and migration based on the results of multiple experiments, such as cell proliferation assays, wound healing assays, and transwell migration assays, that assessed the anti-proliferative and migratory effect on in vitro. The effect of the selected small molecule on the sprouting of VSMCs from endothelium-denuded aortic rings was also examined. The results indicated that the selected small molecule, a spleen tyrosine kinase (Syk) inhibitor (BAY61-3606), is an effective agent for suppressing proliferation and migration of VSMCs in vitro and ex vivo and that has therapeutic potential for treating occlusive vascular disease involving aberrant proliferation and migration of VSMCs.

Results

Initial screening of small molecules for anti-proliferative effect on VSMCs

For initial screening, through a literature search, 43 small molecules (Table 1), whose effects on VSMC proliferation and migration had not been reported, were selected from an in-house small molecule library mainly composed of commercially available inhibitors of six kinase subfamilies [10]. The effect of those 43 small molecules on VSMC proliferation was then examined. VSMCs were treated with each small molecule (10 μM) for 24 h, and cellular proliferation was determined by using a cell proliferation assay kit (CCK-8). The results indicated that the small molecule number 129 most significantly inhibited the proliferation of VSMCs, compared to the vehicle groups (DMSO 2%, v/v) (Fig. 1). The identity of compound 129 was BAY 61-3606 hydrochloride, a Syk inhibitor [11].
Table 1

List of small molecules used for initial screening

D2

p-Aminoclonidine hydrochloride

D3

Isoetharine mesylate salt

D6

N6-2-(4-aminophenyl) ethyladenosine

D7

ABT-702 dihydrochloride

D9

9-Cyclopentyladenine monomethansulfonate

D14

(−)-p-Bromolevamisole oxalate

D23

TBBz

D24

A3 hydrochloride

D29

Kenpaullone

D35

TG003

D42

DMNB (4,5-dimethoxy-2-nitrobenzaldehyde)

D43

R(+)-6-Bromo-APB hydrobromide

D44

S-(−)-Eticlopride hydrochloride

D45

BP897

D46

GW2974

D50

SCH-202676 hydrobromide

D58

I-OMe-Tyrphostin AG 538

D59

IRAK-1/4 inhibitor-1

D60

ZM 39923 hydrochloride

D64

Pinacidil monohydrate

D66

NS 8593 hydrochloride

D68

PD 98059

D74

CGP 57380

D75

Triamterene

D78

Amiloride hydrochloride hydrate

D80

Prilocaine hydrochloride

D85

N-p-Tosyl-l-phenylalanine chloromethyl ketone

D87

N-(3,3-Diphenylprophyl)glycinamide

D88

JX401

D89

SD-169

D94

Enoximone, >99% HPLC

D95

4-(3-Butoxy-4-methoxybenzyl)imidazolidin-2-one

D97

YM 976

D101

AS604850

D104

7,8-Dihydroxycoumarin

D105

8-(4-chlorophenylthio) adenosine 3ʹ,5ʹ-cyclic monophosphate sodium salt

D110

Hispidin

D119

BTO-1

D129

BAY 61-3606 hydrochloride

D134

Tyrphostin AG879

D135

SU4321

D143

Tetracaine hydrochloride

D144

Vanillic acid diethylamide

Fig. 1

Initial screening of small molecules for VSMC proliferation suppression. A total of 43 small molecule inhibitors of various kinases with no reported anti-proliferative effect on VSMC were screened. Rat VSMCs were treated with 10 μM of each small molecule for 24 h, and the cellular proliferation was evaluated by cell counting kits (CCK-8). Un (vehicle): 10% FBS supplemented DMSO containing DMSO 2%, v/v, indicated as white box with oblique pattern. Blue arrow indicates the most effective small molecule. The quantitative data were expressed as the mean ± SEM of at least three independent experiments. Full names of each small molecule are listed in Table 1

BAY61 inhibits VSMC proliferation in a concentration and time-dependent manner

To examine the concentration-dependent effect of the Syk inhibitor (BAY61), VSMCs were treated with increasing concentrations of BAY61 (1, 5, 10, and 20 μM) for 24 h. The cellular proliferation results indicated that BAY61 had a significant anti-proliferative effect at all concentrations tested, although the effect was more profound with concentrations of 5 μM or higher (Fig. 2a, b). At the concentration of 10 μM, BAY61 showed a significant anti-proliferative effect without any prominent morphological changes. On the other hand, at a concentration of 20 μM, the cells started to detach from the culture plate and to clump together. Therefore, for further experiments, 10 μM was used to examine the anti-proliferative effects of BAY61. To further examine the time-dependent effect of BAY61, VSMCs were treated with 10 μM of BAY61 for up to 48 h, and the cellular proliferation was decreased by BAY61 in a time-dependent manner (Fig. 2c).
Fig. 2

BAY61 inhibits VSMC proliferation in a concentration and time-dependent manner. a Representative images of VSMCs cultured with increasing concentrations of BAY61 for 24 h. Scale bar 200 μm. b The concentration-dependent effect of BAY61 on VSMC proliferation was determined after 24 h of BAY61 treatment as indicated using cell counting kit (CCK-8). *p < 0.05, **p < 0.01 compared to 10% FBS control. c To examine the time-dependent effect of BAY61, VSMCs were cultured in 10% FBS supplemented DMEM containing either vehicle (DMSO 2%, v/v) or 10 μM of BAY61 for up to 48 h. Cellular proliferation was determined by using CCK-8. *p < 0.05, **p < 0.01 compared to 10% FBS control. The quantitative data were expressed as the mean ± SEM of at least three independent experiments

Anti-migratory effect of the Syk inhibitor

To evaluate the anti-migratory effect of BAY61, wound healing assays and transwell migration assays were conducted. According to the data, when the cells were stimulated with 10% FBS, the scratching wound produced with a yellow pipet tip was approximately 90% closed at 24 h, but the wound treated with BAY61 (10 μM) remained about 50% unclosed (Fig. 3a). Furthermore, BAY61 apparently decreased the number of cells that migrated through the transwell even in the presence of 10% serum (Fig. 3b).
Fig. 3

BAY61 suppresses migration of VSMCs. a Representative images of VSMC wound healing with or without BAY61 treatment. The cells were treated with either vehicle (DMSO 2%) or BAY61 (10 μM) after wound was generated by scratching with a yellow pipette tip. The cellular migration was monitored for 24 h. Dotted line indicates leading edge. Scale bar 200 μm. *p < 0.05. The quantitative data were expressed as the mean ± SEM of at least three independent experiments. b The anti-migratory effect of BAY61 (10 μM, 24 h) was evaluated by using transwell migration assay. Scale bar 200 μm

BAY61 suppresses VSMC sprouting from aortic rings ex vivo

To further investigate the effect of BAY61 on VSMC proliferation, an ex vivo aortic ring assay was performed. The endothelium-denuded thoracic aortas of rats were cut to prepare aortic rings with thickness of 1 mm. Matrigel-embedded aortic rings were cultured in 10% FBS-supplemented DMEM with either vehicle (DMSO 2%, v/v) or BAY61 (10 μM) for 7 days. VSMC sprouting from the endothelium-denuded aortic rings was inhibited by BAY61 even in the presence of 10% FBS in the culture medium (Fig. 4).
Fig. 4

BAY61 attenuates VSMC outgrowth from endothelium denuded aortic ring. To examine the effect of BAY61 on the outgrowth of VSMCs from blood vessel, segments of endothelium-denuded aortic rings embedded in Matrigel were treated with either vehicle (DMSO 2%, v/v) or BAY61 (10 μM) for 7 days. On day 7, the pictures of VSMC sprouting from the aortic ring were taken. White arrows indicate the sprouting of VSMCs from the aortic rings. *p < 0.05. The quantitative data were expressed as the mean ± SEM of at least three independent experiments

Discussion

In the present study, through a screening of small molecule inhibitors of kinase subfamilies, we identified a Syk inhibitor as a potent anti-proliferative and migratory small molecule for VSMCs. Protein kinases are known to play critical roles in signaling pathways implicated in development, differentiation, death and proliferation of cells [12]. Therefore, it is reasonable to hypothesize that a certain kinase inhibitor can suppress proliferation and migration of VSMCs. Regarding the effect of BAY61 on cellular proliferation and migration, it has been reported that BAY61 significantly reduced the proliferation and migration of multiple myeloma cells [13] and it prevented airway epithelial cell proliferation and migration [14]. However, to our best knowledge, no previous study had reported anti-proliferative and migratory effects of this particular small molecule on VSMCs. Therefore, the present study is the first study to examine the effect of BAY61 on VSMC proliferation and migration.

Syk, along with zeta-chain associated kinase of 70 kDa (Zap-70), is a member of the Syk family of kinases that are activated downstream of Src kinases [15]. Syk is known to be mainly expressed in hematopoietic cells, but its expression has been also reported in epithelial cells and endothelial cells [16, 17]. The reported roles of Syk include, but not limited to, relaying adaptive immune receptor signaling, cellular adhesion, innate immune recognition, platelet activation, and vascular development [18]. Pertaining to the role of Syk in VSMC proliferation, it has been reported that inhibition or knockdown of Syk significantly prevented platelet-derived growth factor (PDGF)-induced proliferation and migration [19].

Our data also clearly demonstrated that the Syk inhibitor BAY61 significantly suppressed VSMC proliferation and migration. Previous study had reported that suppression of Syk activation led to subsequent inhibition of extracellular signal-regulated kinas (ERK) 1/2 signaling and p38 mitogen-activated protein kinase signaling [20]. Therefore, it is highly possible that BAY61 also inhibited VSMC proliferation and migration via suppression of ERK and p38 pathways. Although we did not examined detailed mechanisms of BAY61 and it is a major limitation of the present study, we are currently conducting a further study evaluating the in vivo efficacy of BAY61 in comparison to other well-known SMC proliferation inhibitor such as paclitaxel and the underlying mechanism of BAY61 will be also examined in detail.

Our ex vivo aortic ring assay result showed that BAY61 prevented sprouting of VSMCs, and furthermore, suppression of Syk has been suggested to be an effective way to control atherosclerosis via subsequent suppression of endothelin-1 production from endothelial cells [21]. Therefore, BAY61 is a strong candidate for an effective therapeutic agent targeting occlusive vascular diseases, such as restenosis, and it deserves further investigation to prove its in vivo efficacy and safety.

Conclusions

In summary, as an effort to identify anti-proliferative agent to control occlusive vascular disease, this paper describes the anti-proliferative and migratory effects of BAY61, a Syk inhibitor, on VSMCs for the first time. The selected Syk inhibitor significantly suppressed VSMC proliferation and migration in vitro and ex vivo. These data suggest that the BAY61 may be a potent therapeutic agent for the treatment of occlusive vascular disease and warrants further studies to evaluate its in vivo efficacy and detailed underlying mechanism.

Methods

Isolation and culture of rat aortic VSMCs

All experimental procedures for animal studies were approved by the Committee for the Care and Use of Laboratory Animals, Yonsei University College of Medicine, and were performed in accordance with the Committee’s guidelines and regulations for animal care. Rat aortic VSMCs were isolated and cultured using methods previously published [22]. The thoracic aortas from 6- to 8-week-old Sprague–Dawley rats were removed and transferred to serum-free Dulbecco’s modified Eagle’s medium (DMEM; Invitrogen, USA) containing 100 units/ml penicillin and 100 mg/ml streptomycin. The connective tissues were removed, and the aorta was transferred to a petri dish containing 5 ml of an enzyme dissociation mixture containing DMEM with 1 mg/ml collagenase type I (Sigma, USA) and 0.5 mg/ml elastase (USB Bioscience, USA) and was incubated for 30 min at 37 °C. The adventitia was stripped with forceps under a microscope. The aorta was transferred to a plastic tube containing 5 ml enzyme dissociation mixture and incubated for 2 h at 37 °C. The suspension was centrifuged (1500 rpm for 10 min), and the pellet was re-suspended with 10% fetal bovine serum (FBS) containing DMEM with. Rat aortic SMCs were cultured in DMEM supplemented with 10% FBS, 100 IU/ml penicillin and 100 mg/ml streptomycin in 75 cm2 flasks at 37 °C in a humidified atmosphere of 95% air and 5% CO2 (Forma Scientific, USA).

Primary screening of small molecules

From an in-house small molecule library mainly composed of inhibitors of six major kinase subfamilies, 43 candidate small molecules with no known anti-proliferative effects on VSMCs were selected based on a published literature search using Pubmed (http://www.ncbi.nlm.nih.gov/pubmed). For primary screening, VSMCs were seeded in 48-well culture plates using DMEM with 10% FBS and then treated with 10 μM of each candidate compound for 24 h. The anti-proliferative effects of the candidate compounds were determined by a cell proliferation assay.

Cell proliferation assay (cell counting kit 8, CCK 8)

To determine cell proliferation, cell proliferation assay using a WST-8 [2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt] solution (CCK-8, Dojindo, Japan) was conducted following protocol previously published [23]. Briefly, WST-8 solution was added to each well [10% (v/v)] and incubated at 37 °C for 2 h to allow for the formation of WST-8 formazan. The absorbance of a water soluble formazan dye was measured at 450 nm using a microplate reader (Molecular Devices, USA).

Wound healing assay

Wound healing assay, also as known as in vitro scratch assay, was conducted according to the protocol previously published [24]. VSMCs were plated at a density of 8 × 104 cells/well in six-well plates. After the cells had reached 90% confluence, wounds were produced by scratching with 200 μl pipette tips. The leading edge of the wounds was marked as a baseline. The medium was replaced with or without the chemical compound, and the cells were incubated for up to 48 h. Images were captured using an Axiovert 40C inverted microscope (Carl Zeiss, Germany) equipped with a Powershot A640 digital camera (Canon, Japan). The percent area remained unclosed (area between the leading edges at a given time point/area between the leading edges at baseline × 100) was measured.

Transwell migration assay

Transwell migration assay was performed according to the protocol previously published [25]. VSMCs (8 × 103 cells) were seeded onto the upper chamber of a transwell filter with 8 μm pores (Costar Corning, USA). The cells were deprived of serum for 24 h, and a candidate chemical compound was added to the lower chamber. Transwell chambers were incubated at 37 °C for 24 h. After incubation, the cells that migrated through the pores of the filter were stained with 0.25% crystal violet. Non-migrating cells on the upper side of the filter were removed with cotton swabs.

Western Blot analysis

VSMCs cultured in 60-mm dishes were treated with or without the selected chemical compound. Proteins were separated in a 10% SDS–polyacrylamide gel and transferred to PVDF membranes (Millipore, USA). After blocking the membrane with TBS-T (TBS-tween 20, 0.1% tween 20) containing 5% (w/v) non-fat dried skimmed milk powder for 1 h at room temperature, the membranes were washed twice with TBS-T and incubated with primary antibodies for 1 h at room temperature or overnight at 4 °C. The membranes were washed three times with TBS-T for 5 min and incubated with horseradish peroxidase (HRP)-conjugated secondary antibody for 1 h at room temperature. After extensive washing, the bands were detected using enhanced chemiluminescence (ECL®) reagent (AbClon, Republic of Korea). The band intensities were detected using a Photo-Image System (Molecular Dynamics, Canada). The primary antibodies were from Cell Signaling (cyclin D1:2978, p-ERK:9101, ERK:9102, p-Akt:9271, Akt:9272), Santa Cruz [PCNA (proliferating cell nuclear antigen):sc-56, p-Rb:sc-16670-R, Rb:sc-50], and Abcam (β-actin:ab8227).

Ex vivo aortic ring assay

Aortic ring assay to monitor the outgrowth of VSMCs was conducted following a published protocol with modifications [26]. Briefly, the thoracic aortas from 6- to 8-week-old Sprague–Dawley rats were removed and transferred to serum-free DMEM. The lining endothelium was denuded using a 2-Fr Fogarty balloon catheter (Baxter, USA) to minimize the possibility of endothelial cell sprouting during the ring assay. The aortas were washed by gradually passing through PBS three times. After removing perivascular adipose tissue, each aorta was cut into segments of aortic rings 1 mm in length that were placed in Matrigel (BD Biosciences, USA). The aortic rings were incubated with or without the selected chemical compound. Over the next 7 days, the aorta rings were monitored daily for the sprouting of VSMCs using a microscope.

Statistical analysis

Quantitative data were expressed as the mean ± SEM (standard error of measurement). For statistical analysis, one-way ANOVA with Bonferroni correction was performed using OriginPro 8 SR4 software (ver. 8.0951, OriginLab Corporation, USA) if there were more than three groups. A p value of less than 0.05 was considered statistically significant.

Declarations

Authors’ contributions

HS participated in the study design, carried out cell culture including cell preparation, and revised the manuscript. SK drafted the manuscript and carried out small molecule screening. CL, KL, and JL participated in cell preparation and cell culture. SLim provided technical support. SLee conceived the study, drafted the manuscript, and revised the manuscript. KH conceived the study and edited the manuscript. All authors read and approved the final manuscript.

Acknowledgements

This study was supported by grants funded by the Korea Ministry of Science, ICT and Future Planning (NRF-2015M3A9E6029519, and NFR-2015M3A9E6029407).

Competing interests

The authors declare that they have no competing interests.

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Authors’ Affiliations

(1)
Brain Korea 21 PLUS Project for Medical Science, Yonsei University
(2)
Institute for Bio-Medical Convergence, College of Medicine, Catholic Kwandong University
(3)
Department of Integrated Omics for Biomedical Sciences, Yonsei University
(4)
Department of Veterinary Physiology, College of Veterinary Medicine, Chonbuk National University

References

  1. Rensen SS, Doevendans PA, van Eys GJ. Regulation and characteristics of vascular smooth muscle cell phenotypic diversity. Neth Heart J. 2007;15(3):100–8.View ArticlePubMedPubMed CentralGoogle Scholar
  2. Gomez D, Owens GK. Smooth muscle cell phenotypic switching in atherosclerosis. Cardiovasc Res. 2012;95(2):156–64.View ArticlePubMedPubMed CentralGoogle Scholar
  3. Louis SF, Zahradka P. Vascular smooth muscle cell motility: from migration to invasion. Exp Clin Cardiol. 2010;15(4):e75–85.PubMedPubMed CentralGoogle Scholar
  4. Owens GK, Kumar MS, Wamhoff BR. Molecular regulation of vascular smooth muscle cell differentiation in development and disease. Physiol Rev. 2004;84(3):767–801.View ArticlePubMedGoogle Scholar
  5. Rzucidlo EM, Martin KA, Powell RJ. Regulation of vascular smooth muscle cell differentiation. J Vasc Surg. 2007;45(Suppl A):A25–32.View ArticlePubMedGoogle Scholar
  6. Clowes AW, Reidy MA. Prevention of stenosis after vascular reconstruction: pharmacologic control of intimal hyperplasia—a review. J Vasc Surg. 1991;13(6):885–91.View ArticlePubMedGoogle Scholar
  7. Farooq V, Gogas BD, Serruys PW. Restenosis: delineating the numerous causes of drug-eluting stent restenosis. Circ Cardiovasc Interv. 2011;4(2):195–205.View ArticlePubMedGoogle Scholar
  8. Garg S, Serruys PW. Coronary stents: current status. J Am Coll Cardiol. 2010;56(10 Suppl):S1–42.View ArticlePubMedGoogle Scholar
  9. Schomig A, Kastrati A, Wessely R. Prevention of restenosis by systemic drug therapy: back to the future? Circulation. 2005;112(18):2759–61.View ArticlePubMedGoogle Scholar
  10. Hwang KC, Kim JY, Chang W, Kim DS, Lim S, Kang SM, et al. Chemicals that modulate stem cell differentiation. Proc Natl Acad Sci USA. 2008;105(21):7467–71.View ArticlePubMedPubMed CentralGoogle Scholar
  11. Yamamoto N, Takeshita K, Shichijo M, Kokubo T, Sato M, Nakashima K, et al. The orally available spleen tyrosine kinase inhibitor 2-[7-(3,4-dimethoxyphenyl)-imidazo[1,2-c]pyrimidin-5-ylamino]nicotinamide dihydrochloride (BAY 61-3606) blocks antigen-induced airway inflammation in rodents. J Pharmacol Exp Ther. 2003;306(3):1174–81.View ArticlePubMedGoogle Scholar
  12. Bononi A, Agnoletto C, De Marchi E, Marchi S, Patergnani S, Bonora M, et al. Protein kinases and phosphatases in the control of cell fate. Enzyme Res. 2011;2011:329098.View ArticlePubMedPubMed CentralGoogle Scholar
  13. Koerber RM, Held SA, Heine A, Kotthoff P, Daecke SN, Bringmann A, et al. Analysis of the anti-proliferative and the pro-apoptotic efficacy of Syk inhibition in multiple myeloma. Exp Hematol Oncol. 2015;4:21.View ArticlePubMedPubMed CentralGoogle Scholar
  14. Wang X, Mychajlowycz M, Lau C, Gutierrez C, Scott JA, Chow CW. Spleen tyrosine kinase mediates BEAS-2B cell migration and proliferation and human rhinovirus-induced expression of vascular endothelial growth factor and interleukin-8. J Pharmacol Exp Ther. 2012;340(2):277–85.View ArticlePubMedGoogle Scholar
  15. Bradshaw JM. The Src, Syk, and Tec family kinases: distinct types of molecular switches. Cell Signal. 2010;22(8):1175–84.View ArticlePubMedGoogle Scholar
  16. Kurosaki T. Functional dissection of BCR signaling pathways. Curr Opin Immunol. 2000;12(3):276–81.View ArticlePubMedGoogle Scholar
  17. Inatome R, Yanagi S, Takano T, Yamamura H. A critical role for Syk in endothelial cell proliferation and migration. Biochem Biophys Res Commun. 2001;286(1):195–9.View ArticlePubMedGoogle Scholar
  18. Mocsai A, Ruland J, Tybulewicz VL. The SYK tyrosine kinase: a crucial player in diverse biological functions. Nat Rev Immunol. 2010;10(6):387–402.View ArticlePubMedPubMed CentralGoogle Scholar
  19. Gao Z, Cao L, Luo Q, Wang X, Yu L, Wang T, et al. Spleen tyrosine kinase modulates the proliferation and phenotypes of vascular smooth muscle cells induced by platelet-derived growth factor. DNA Cell Biol. 2011;30(3):149–55.View ArticlePubMedGoogle Scholar
  20. Lee CK, Lee HM, Kim HJ, Park HJ, Won KJ, Roh HY, et al. Syk contributes to PDGF-BB-mediated migration of rat aortic smooth muscle cells via MAPK pathways. Cardiovasc Res. 2007;74(1):159–68.View ArticlePubMedGoogle Scholar
  21. Kim YJ, Koo TY, Yang WS, Han NJ, Jeong JU, Lee SK, et al. Activation of spleen tyrosine kinase is required for TNF-alpha-induced endothelin-1 upregulation in human aortic endothelial cells. FEBS Lett. 2012;586(6):818–26.View ArticlePubMedGoogle Scholar
  22. Kim MH, Ham O, Lee SY, Choi E, Lee CY, Park JH, et al. MicroRNA-365 inhibits the proliferation of vascular smooth muscle cells by targeting cyclin D1. J Cell Biochem. 2014;115(10):1752–61.View ArticlePubMedGoogle Scholar
  23. Ishiyama M, Miyazono Y, Sasamoto K, Ohkura Y, Ueno K. A highly water-soluble disulfonated tetrazolium salt as a chromogenic indicator for NADH as well as cell viability. Talanta. 1997;44(7):1299–305.View ArticlePubMedGoogle Scholar
  24. Liang CC, Park AY, Guan JL. In vitro scratch assay: a convenient and inexpensive method for analysis of cell migration in vitro. Nat Protoc. 2007;2(2):329–33.View ArticlePubMedGoogle Scholar
  25. Marshall J. Transwell((R)) invasion assays. Methods Mol Biol. 2011;769:97–110.View ArticlePubMedGoogle Scholar
  26. Baker M, Robinson SD, Lechertier T, Barber PR, Tavora B, D’Amico G, et al. Use of the mouse aortic ring assay to study angiogenesis. Nat Protoc. 2011;7(1):89–104.View ArticlePubMedGoogle Scholar

Copyright

© The Author(s) 2017