Scriptaid

Scriptaid/exercise-induced lysine acetylation is another type of posttranslational modification occurring in titin

Titin serves important functions in skeletal muscle during exercise, and posttranslational modifications of titin participate in the regulation of titin-based sarcomeric functions. Scriptaid has exercise-like effects through the inhibition of HDAC and regulatory acetylation of proteins. However, it remains mostly unclear if exercise could result in titin's acetylation and whether Scriptaid could regulate acetylation of titin. We treated C57BL/6 mice with 6-wk treadmill exercise and 6-wk Scriptaid administration to explore Scriptaid's effects on mice exercise capacity and whether Scriptaid administration/exercise could induce titin's acetylation modification. An exercise endurance test was conducted to explore their effects on mice exercise capacity, and proteomic studies were conducted with gastrocnemius muscle tissue of mice from different groups to explore titin's acetylation modification. We found that Scriptaid and exercise did not change titin's protein expression, but they did induce acetylation modification changes of titin. In total, 333 acetylated lysine sites were identified. Exercise changed the acetylation levels of 33 lysine sites of titin, whereas Scriptaid changed acetylation levels of 31 titin lysine sites. Exercise treatment and Scriptaid administration shared 11 lysine sites. In conclusion, Scriptaid increased exercise endurance of mice by increasing the time mice spent running to fatigue. Acetylation is a common type of posttranslational modification of titin, and exercise/Scriptaid changed the acetylation levels of titin and titin-interacting proteins. Most importantly, titin may be a mediator through which Scriptaid and exercise modulate the properties and functions of exercise-induced skeletal muscle at the molecular level.NEW & NOTEWORTHY Scriptaid administration increased mouse exercise endurance. Acetylation is another type of posttranslational modification of titin. Scriptaid/exercise changed acetylation levels of titin and titin-interacting proteins. Titin may mediate exercise-induced skeletal muscle properties and functions.

Anti-Cancer Effects of Epigenetics Drugs Scriptaid and Zebularine in Human Breast Adenocarcinoma Cells

Background: High relapse and metastasis progression in breast cancer patients have prompted the need to explore alternative treatments. Epigenetic therapy has emerged as an attractive therapeutic strategy due to the reversibility of epigenome structures.
Objective: This study investigated the anti-cancer effects of epigenetic drugs scriptaid and zebularine in human breast adenocarcinoma MDA-MB-231 and MCF-7 cells.
Methods: First, the half maximal Inhibitory Concentration (IC₅₀) of scriptaid and zebularine, and the combination of both drugs on human breast adenocarcinoma MDA-MB-231 cells were determined. Next, MDA-MB-231 and MCF-7 cells were treated with IC₅₀ of scriptaid, zebularine and the combination of both. After IC₅₀ treatments, the anti-cancer effects were evaluated via cell migration assay, cell cycle analysis and apoptotic studies which included histochemical staining and reverse-transcriptase polymerase chain reaction (RT-PCR) of the apoptotic genes.
Results: Both epigenetic drugs inhibited cell viability in a dose-dependent manner with IC₅₀ of 2 nM scriptaid, 8 μM zebularine and a combination of 2 nM scriptaid and 2 μM zebularine. Both MDA-MB-231 and MCF-7 cells exhibited a reduction in cell migration after the treatments. In particular, MDA-MB-231 cells exhibited a significant reduction in cell migration (p < 0.05) after the treatments of zebularine and the combination of scriptaid and zebularine. Besides, cell cycle analysis demonstrated that scriptaid and the combination of both drugs could induce cell cycle arrest at the G₀/G₁ phase in both MDA-MB-231 and MCF-7 cells. Furthermore, histochemical staining allowed the observation of apoptotic features, such as nuclear chromatin condensation, cell shrinkage, membrane blebbing, nuclear chromatin fragmentation and cytoplasmic extension, in both MDA-MB-231 and MCF-7 cells after the treatments. Further, apoptotic studies revealed the upregulation of pro-apoptotic Bax, downregulation of anti-apoptotic Bcl-2 and elevation of Bax/Bcl-2 ratio in MDA-MB-231 cells treated with zebularine and MCF-7 cells treated with all drug regimens.
Conclusion: Collectively, these findings suggest that scriptaid and zebularine are potential anti-cancer drugs, either single or in combination, for the therapy of breast cancer. Further investigations of the gene regulatory pathways directed by scriptaid and zebularine are definitely warranted in the future.

Scriptaid improves the reprogramming of donor cells and enhances canine-porcine interspecies embryo development

Histone methylation, histone acetylation, and DNA methylation are the important factors for somatic cell nuclear transfer (SCNT). Histone deacetylase inhibitors (HDACi) and DNA methyltransferase inhibitors (DNMTi) have been used to improve cloning efficiency. In particular, scriptaid, an HDACi, has been shown to improve SCNT efficiency. However, no studies have been performed on canines. Here, we evaluated the effects of scriptaid on histone modification in canine ear fibroblasts (cEFs) and cloned canine embryos derived from cEFs. The early development of cloned canine-porcine interspecies SCNT (iSCNT) embryos was also examined. cEFs were treated with scriptaid (0, 100, 250, 500, 750, and 1000nM) in a medium for 24h. Scriptaid treatment (all concentrations) did not significantly affect cell apoptosis. Treatment with 500nM scriptaid caused a significant increase in the acetylation of H3K9, H3K14, and H4K5. cEFs treated with 500nM scriptaid showed significantly decreased Gcn5, Hat1, Hdac6, and Bcl2 and increased Oct4 and Sox2 expression levels. After SCNT with canine oocytes, H3K14 acetylation was significantly increased in the one- and two-cell cloned embryos from scriptaid-treated cEFs. In iSCNT, the percentage of embryos in the 16-cell stage was significantly higher in the scriptaid-treated group (21.6±2.44%) than in the control (7.5±2.09%). The expression levels of Oct4, Sox2, and Bcl2 were significantly increased in 16-cell iSCNT embryos, whereas that of Hdac6 was decreased. These results demonstrated that scriptaid affected the reprogramming of canine donor and cloned embryos, as well as early embryo development in canine-porcine iSCNT, by regulating reprogramming and apoptotic genes.

Scriptaid enhances skeletal muscle insulin action and cardiac function in obese mice

Aim: To determine the effect of Scriptaid, a compound that can replicate aspects of the exercise adaptive response through disruption of the class IIa histone deacetylase (HDAC) corepressor complex, on muscle insulin action in obesity.
Materials and methods: Diet-induced obese mice were administered Scriptaid (1 mg/kg) via daily intraperitoneal injection for 4 weeks. Whole-body and skeletal muscle metabolic phenotyping of mice was performed, in addition to echocardiography, to assess cardiac morphology and function.
Results: Scriptaid treatment had no effect on body weight or composition, but did increase energy expenditure, supported by increased lipid oxidation, while food intake was also increased. Scriptaid enhanced the expression of oxidative genes and proteins, increased fatty acid oxidation and reduced triglycerides and diacylglycerides in skeletal muscle. Furthermore, ex vivo insulin-stimulated glucose uptake by skeletal muscle was enhanced. Surprisingly, heart weight was reduced in Scriptaid-treated mice and was associated with enhanced expression of genes involved in oxidative metabolism in the heart. Scriptaid also improved indices of both diastolic and systolic cardiac function.
Conclusion: These data show that pharmacological targeting of the class IIa HDAC corepressor complex with Scriptaid could be used to enhance muscle insulin action and cardiac function in obesity.

Scriptaid inhibits cell survival, cell cycle, and promotes apoptosis in multiple myeloma via epigenetic regulation of p21

Multiple myeloma (MM) is an extremely serious plasma cell malignancy. Despite the recent introduction of chemotherapies such as bortezomib and lenalidomide, it remains an incurable disease due to the high rate of relapse and the development of drug resistance. Epigenetic regulation is closely related to MM progression, but the epigenetic modification mechanism of MM cell apoptosis has remained unclear. As a novel histone deacetylase inhibitor (HDACi), Scriptaid's possible roles in MM progression have not been explored. Herein, we found that Scriptaid decreased several human MM cell viabilities in a dose-dependent manner. Scriptaid was also able to dose dependently and significantly induce MM cell cycle arrest at the G₂/M phase. Moreover, Scriptaid facilitates p21 transcriptional activities by mediating H3Ac gene-activated modification, eventually leading to MM cell apoptosis. Overall, our results show that Scriptaid is an inducer of MM cell death, suggesting the possibility for Scriptaid-mediated therapeutics to cure refractory/relapsed MM.