Galangin Inhibits Thrombin-Induced MMP-9 Expression in SK-N-SH Cells via Protein Kinase-Dependent NF-κB Phosphorylation.

Chien-Chung Yang,Chien-Chung Yang,Chien-Chung Yang,Chih-Chung Lin,Chih-Chung Lin,Chuen-Mao Yang,Li-Der Hsiao,Li-Der Hsiao

doi:10.3390/ijms19124084

Abstract

Galangin, a member of the flavonol compounds of the flavonoids, could exert anti-inflammatory effects in various cell types. It has been used for the treatment of arthritis, airway inflammation, stroke, and cognitive impairment. Thrombin, one of the regulators of matrix metalloproteinase (MMPs), has been known as a vital factor of physiological and pathological processes, including cell migration, the blood–brain barrier breakdown, brain edema formation, neuroinflammation, and neuronal death. MMP-9 especially may contribute to neurodegenerative diseases. However, the effect of galangin in combating thrombin-induced MMP-9 expression is not well understood in neurons. Therefore, we attempted to explore the molecular mechanisms by which galangin inhibited MMP-9 expression and cell migration induced by thrombin in SK-N-SH cells (a human neuroblastoma cell line). Gelatin zymography, western blot, real-time PCR, and cell migration assay were used to elucidate the inhibitory effects of galangin on the thrmbin-mediated responses. The results showed that galangin markedly attenuated the thrombin-stimulated phosphorylation of proto-oncogene tyrosine-protein kinase (c-Src), proline-rich tyrosine kinase 2 (Pyk2), protein kinase C (PKC)α/β/δ, protein kinase B (Akt), mammalian target of rapamycin (mTOR), p42/p44 mitogen-activated protein kinase (MAPK), Jun amino-terminal kinases (JNK)1/2, p38 MAPK, forkhead box protein O1 (FoxO1), p65, and c-Jun and suppressed MMP-9 expression and cell migration in SK-N-SH cells. Our results concluded that galangin blocked the thrombin-induced MMP-9 expression in SK-N-SH cells via inhibiting c-Src, Pyk2, PKCα/βII/δ, Akt, mTOR, p42/p44 MAPK, JNK1/2, p38 MAPK, FoxO1, c-Jun, and p65 phosphorylation and ultimately attenuated cell migration. Therefore, galangin may be a potential candidate for the management of brain inflammatory diseases.

Highlights

Matrix metalloproteinases (MMPs), a series of zinc-dependent endopeptidases, consist of more than 20 members, including the MMPs of humans and other species
Thwereeffuorrteh,ewr eexfpulrothreedr wexhpeltohreerdgwalhanetghinerrgedaluacnegdinthreedMuAcePdKsth-deeMpeAnPdKenst-dpeapthewndayens taspsaotchiwataedyswaistshotchiaeted wiatthtenthueataiottnenouf athtiroonmboifnt-hinrdoumcbedinM-inMdPu-c9edexpMreMssPio-9n.eWxperefosusinodn.thW at eprfeoturenadtmthenatt wpritehtrgeaaltamnegnint (w3 ith galangin (3 μM) attenuated the thrombin-stimulated phosphorylation of p44/p42 mitogen-activated protein kinase (MAPK) (Figure 5A), p38 MAPK (Figure 5B), and JNK1/2 (Figure 5C) in SK-N-SH cells. These results indicated that galangin-reduced thrombin-induced MMP-9 expression is mediated via suppressing the MAPKs activation in SK-N-SH cells
We extended the inhibitory effects of galangin on thrombin-induced MMP-9 expression and cell migration through the suppression of the activation of different protein kinases, including non-receptor tyrosine receptor kinases (nRTKs), protein kinase C (PKC), Akt, mammalian target of rapamycin (mTOR), MAPKs, and transcription factors, such as nuclear factor-κB (NF-κB), activator protein 1 (AP-1), and forkhead box protein O1 (FoxO1), in human SK-N-SH cells

Summary

Introduction

Matrix metalloproteinases (MMPs), a series of zinc-dependent endopeptidases, consist of more than 20 members, including the MMPs of humans and other species They are typically secreted or anchored to the cell surface; thereby, they can catalyze the degradation of proteins within the secretory pathway or the extracellular matrix (ECM). It has been shown for decades that the upregulation of MMP-9 has played a vital role in neuroinflammatory and neurodegenerative disorders [7,8]. These links have been made by the finding of BBB damage leading to cerebral edema, excitotoxicity, neuronal damage, apoptosis, and hemorrhagic transformation by MMP-9 in brain insults [9,10,11]. It can be speculated that adjuvant intervention with gelatinases inhibitors might diminish the disease severity and brain injury by stabilizing the BBB in cases of acute stages of stroke or demyelination disorder

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