Sophora flavescens Aiton Decreases MPP+-Induced Mitochondrial Dysfunction in SH-SY5Y Cells.

Hee-Young Kim,Seungtae Kim,Hyongjun Jeon,Sungtae Koo,Hyungwoo Kim

doi:10.3389/fnagi.2018.00119

Abstract

Sophora flavescens Aiton (SF) has been used to treat various diseases including fever and inflammation in China, South Korea and Japan. Several recent reports have shown that SF has anti-inflammatory and anti-apoptotic effects, indicating that it is a promising candidate for treatment of Parkinson’s disease (PD). We evaluated the protective effect of SF against neurotoxin 1-methyl-4-phenylpyridinium ion (MPP+)-induced mitochondrial dysfunction in SH-SY5Y human neuroblastoma cells, an in vitro PD model. SH-SY5Y cells were incubated with SF for 24 h, after which they were treated with MPP+. MPP+-induced cytotoxicity and apoptosis were confirmed by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling assay. MitoSOX red mitochondrial superoxide indicator, tetramethylrhodamine methyl ester perchlorate and Parkin, PTEN-induced putative kinase 1 (PINK1), and DJ-1 immunofluorescent staining were conducted to confirm the mitochondrial function. In addition, western blot was performed to evaluate apoptosis factors (Bcl-2, Bax, caspase-3 and cytochrome c) and mitochondrial function-related factors (Parkin, PINK1 and DJ-1). SF suppressed MPP+-induced cytotoxicity, apoptosis and collapse of mitochondrial membrane potential by inhibiting the increase of reactive oxidative species (ROS) and DNA fragmentation, and controlling Bcl-2, Bax, caspase-3 and cytochrome c expression. Moreover, it attenuated Parkin, PINK1 and DJ-1 expression from MPP+-induced decrease. SF effectively suppressed MPP+-induced cytotoxicity, apoptosis and mitochondrial dysfunction by regulating generation of ROS, disruption of mitochondrial membrane potential, mitochondria-dependent apoptosis and loss or mutation of mitochondria-related PD markers including Parkin, PINK1 and DJ-1.

Highlights

Parkinson’s disease (PD) is an incurable neurodegenerative disorder characterized by bradykinesia, muscle rigidity, tremor and postural instability (Olanow and Tatton, 1999)
When the cells were exposed to MPP+ for 24 h, cell viability was significantly decreased in a dose-dependent manner
The dose of 1 mM MPP+ was used in previous studies (Lee et al, 2011; Janhom and Dharmasaroja, 2015); a dose of 1 mM MPP+ was used for further experiments (Figure 1A)

Summary

Introduction

Parkinson’s disease (PD) is an incurable neurodegenerative disorder characterized by bradykinesia, muscle rigidity, tremor and postural instability (Olanow and Tatton, 1999) These features of PD are associated with the appearance of Lewy bodies in the neuronal cytoplasm and progressive degeneration and death of dopaminergic neurons (DA) in the substantia nigra pars compacta (Moore et al, 2005). MPTP is metabolized into 1-methyl-4-phenylpyridinium ion (MPP+) by monoamine oxidase B in the brain, and MPP+ disturbs mitochondrial respiration by inhibiting mitochondrial complex I. This process leads to abnormal mitochondrial metabolism and generation of reactive oxygen species (ROS) like pathogenesis of PD (Cleeter et al, 1992). Several PD-related substances, such as α-Synuclein, Parkin, PTEN-induced putative kinase 1 (PINK1), DJ-1 and Leucine-rich repeat kinase 2 (LRRK2), are involved in mitochondrial function in DA; loss or mutation of these substances causes cell death (Um et al, 2009; Fernández-Moriano et al, 2015; RequejoAguilar and Bolaños, 2016)

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Conclusion