Triptolide increases transcript and protein levels of survival motor neurons in human SMA fibroblasts and improves survival in SMA‐like mice

Abstract

BACKGROUND AND PURPOSE Spinal muscular atrophy (SMA) is a progressive neuromuscular disease. Since disease severity is related to the amount of survival motor neuron (SMN) protein, up‐regulated functional SMN protein levels from the SMN2 gene are considered a major SMA drug‐discovery strategy. In this study, we investigated the possible effects of triptolide, a diterpene triepoxide purified from Tripterygium wilfordii Hook. F., as a new compound for increasing SMN protein. EXPERIMENTAL APPROACH The effects and mechanisms of triptolide on the production of SMA protein were determined by cell‐based assays using the motor neuronal cell line NSC34 and skin fibroblasts from SMA patients. Wild‐type (Smn+/+SMN2−/−, C57BL/6) and SMA‐like (Smn−/−SMN2) mice were injected with triptolide (0.01 or 0.1 mg·kg−1·day−1, i.p.) and their survival rate and level of change in SMN protein in neurons and muscle tissue measured. KEY RESULTS In NSC34 cells and human SMA fibroblasts, pM concentrations of triptolide significantly increased SMN protein expression and the levels of SMN complex component (Gemin2 and Gemin3). In human SMA fibroblasts, triptolide increased SMN‐containing nuclear gems and the ratio of full‐length transcripts (FL‐SMN2) to SMN2 transcripts lacking exon 7 (SMN2Δ7). Furthermore, in SMA‐like mice, triptolide significantly increased SMN protein levels in the brain, spinal cord and gastrocnemius muscle. Furthermore, triptolide treatment increased survival and reduced weight loss in SMA‐like mice. CONCLUSION AND IMPLICATIONS Triptolide enhanced SMN protein production by promoting SMN2 activation, exon 7 inclusion and increasing nuclear gems, and increased survival in SMA mice, which suggests triptolide might be a potential candidate for SMA therapy.

Investigating gene expression differences in two chicken groups with variable propensity to feather pecking

“…; Hsu et al . ). Moreover, SIP1 may play an important role in migraine and the restless leg syndrome in humans (Sabayan et al .…”

Loganin possesses neuroprotective properties, restores SMN protein and activates protein synthesis positive regulator Akt/mTOR in experimental models of spinal muscular atrophy

“…qPCR was performed on the ABI PRISM 7500 Sequence Detector System (Applied Biosystems, Foster City, CA, USA) using Power SYBR Green PCR Master Mix (Applied Biosystems). All primers used were performed as previously described [16]. SMN versus GAPDH transcripts were calculated to obtain the relative threshold cycle (Ct), and the Ct were then related to the Ct of standard sample to obtain 2 -Ct .…”

“…Candidates with enhancing effects on SMN protein and SMN gems in SMA fibroblasts have also been reported for their benefits in lifespan and motor function of SMA mice [16,17].…”

High effectiveness of triptolide, an active diterpenoid triepoxide, in suppressing Kir-channel currents from human glioma cells

“…Sustained membrane depolarization (e.g., in the presence of Trip) is noted to create apparent changes in excitation-transcript coupling found in many types of cells (Dolmetsch, 2003;Franklin et al, 1992;Hsu et al, 2012). Trip has indeed been demonstrated to arrest cancer cells in G 0 -G 1 phase at the concentrations similar to those shown in this study (Zhang et al, 2012).…”

“…Therefore, the pharmacological actions of Trip as described recently Hsu et al, 2012;Lin et al, 2007;Su et al, 2010;Zhang et al, 2012;Zheng et al, 2013) could be partly, if not entirely, connected with its inhibition of Kir-channel activity in glial or glioma cells. However, it also needs to note that mRNA expression for other Kir channels may occur in U373 cells.…”