Supplementary MaterialsSupplementary Figures. promoting effect of SG-Tang on TBP/Q79 SH-SY5Y cells. Furthermore, SG-Tang inhibited aggregation RO9021 and rescued motor-deficits in SCA17 mouse model. The study results suggest the potential of SG-Tang in treating SCA17 and probable other RO9021 polyQ diseases. [11,12] and [13,14]. Antioxidants have been shown to attenuate aggregation and cell death in SCA1, SCA3, and HD models [15C18]. The nuclear factor erythroid 2-related factor 2 (NRF2) and the antioxidant response elements (AREs) signaling pathway is regarded as the major response in the cell to protect against oxidative stress . NRF2 binds to AREs and recruits the general transcriptional machinery for ARE-dependent gene expression when cells respond to oxidative stress. The target genes upregulated by NRF2 including heme oxygenase (decycling) 1 (HMOX1), NAD(P)H dehydrogenase, quinone 1 (NQO1), glutamate-cysteine ligase catalytic subunit (GCLC), and glutathione S-transferase pi 1 (GSTP1) are belonging to the endogenous phase II antioxidative enzymes. Mutant huntingtin and ataxin 3 impaired NRF2 activation and decreased the ARE binding activity, which contributed to mitochondrial dysfunction and enhanced susceptibility to RO9021 oxidative stress in HD and SCA3 cell models [18,20]. Peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (PGC-1) is a known regulator of mitochondrial biogenesis and antioxidative response genes Rabbit Polyclonal to KNG1 (H chain, Cleaved-Lys380) including superoxide dismutase 2, mitochondrial (SOD2) and cytochrome c, somatic (CYCS). PGC-1 null mice developed spongiform neurodegeneration in selective brain areas, which suggests the direct role of PGC-1 in neuronal survival . PGC-1 was recently found also to upregulate the NRF2 transcription . Transcriptional repression of PGC-1 by mutant huntingtin resulting in mitochondrial abnormality and neurodegeneration has also been shown in a HD mouse model, suggesting that agents enhancing the transcriptional activity of PGC-1 may be potential therapeutics for HD [23,24]. Indeed, previously we have shown that herb extract and its constituents, licochalcone A and ammonium glycyrrhizinate, activated PGC-1 activity and NRF2-ARE signaling to increase mitochondrial biogenesis, decrease oxidative stress, and reduce aggregate formation in SCA3 cellular models . Therefore, we propose that PGC-1 and NRF2 pathways may be also compromised in SCA17 and compounds that enhance PGC-1 and/or NRF2 expression may have potential to treat SCA17. Shaoyao and Gancao are Chinese herbal medicines (CHMs) prepared from herbs ((and at a 1:1 ratio. SG-Tang inhibits the production of inflammatory cytokines in serum and brain tissue after cerebral ischemia-reperfusion in rats . We have also shown the antioxidative and aggregation-inhibitory effects of SG-Tang in a tauopathy cell model . We therefore examined the effects of SG-Tang on human Tet-On cells with inducible SCA17 TBP/Q79-GFP expression, which we have established previously . We also explored if SG-Tang exerts its effect via targeting the PGC-1/SOD2/CYCS, NRF2/GCLC/ NQO1, and NFYA/HSPA5 pathways. Furthermore, neuroprotective effect of SG-Tang on a previously established SCA17 TBP/Q109 transgenic mouse model  was investigated. RESULTS SG-Tang reduced TBP/Q79 aggregation and oxidative stress in SCA17 293 cell model Firstly, TBP/Q79-GFP 293 cells were used to evaluate cytotoxicity of SG-Tang. MTT viability test revealed no significant toxic effect on cell survival during 24-h incubation of SG-Tang (97%C93% for 0.1C100 g/ml treatment) (Figure 1A). To further test the polyQ aggregation-inhibitory and ROS-reducing effects of the SG-Tang, the TBP/Q79-GFP cells were treated with SG-Tang (0.001C1000 g/ml) or histone deacetylase inhibitor SAHA (0.1 M, as a positive control)  for 8 h and induced TBP/Q79-GFP expression (by doxycycline) under cell division inhibition (by oxaliplatin) for 6 days (Figure 1B). Representative microscopy images of TBP/Q79-GFP aggregation in untreated or SAHA (0.1 M) or SG-Tang (100 g/ml) treated cells were shown in Figure 1C. SAHA at 0.1 M significantly reduced the TBP/Q79-GFP aggregation to 81% (= 0.001) compared with untreated cells (100%) (Figure 1D). Treatment of SG-Tang at 0.001C100 g/ml also significantly reduced.