JOURNAL OF CELLULAR AND MOLECULAR MEDICINE
·
2021
·Vol. 25
·期 13
·6082-6093
·
IF 5.31
Pin Wang,Juan Zhao,Xiulian Sun
Myocyte enhancer factor 2D (MEF2D) is predominantly expressed in the nucleus and associated with cell growth, differentiation, survival and apoptosis. Previous studies verified that phosphorylation at different amino acids determined MEF2's transcriptional activity which was essential in regulating downstream target genes expression. What regulates phosphorylation of MEF2D and affects its function has not been fully elucidated. Here, we uncovered that dual-specificity tyrosine phosphorylation regulated kinase 1A (DYRK1A), a kinase critical in Down's syndrome pathogenesis, directly bound to and phosphorylated MEF2D at Ser251 in vitro. Phosphorylation of MEF2D by DYRK1A significantly increased MEF2D protein level but attenuated its transcriptional activity, which resulted in decreased transcriptions of MEF2D target genes. Phosphorylation mutated Ser251A MEF2D exhibited enhanced transcriptional activity compared with wild type MEF2D. MEF2D and DYRK1A were observed co-localized in HEK293 and U87MG cells. Moreover, DYRK1A-mediated MEF2D phosphorylation in vitro might influence its nuclear export upon subcellular fractionation, which partially explained the reduction of MEF2D transcriptional activity by DYRK1A. Our results indicated that DYRK1A might be a regulator of MEF2D transcriptional activity and indirectly get involved in regulation of MEF2D target genes.
研究领域:
分子生物学
·
细胞生物学
·
神经生物学
✓ 已验证
DOI
PubMed
高影响因子
MOLECULAR NEUROBIOLOGY
·
2016
·Vol. 54
·期 3
·2209-2222
·
IF 5.397
Chen Zi-wei,Liu Anmin,Liu Qingyu,Chen Jingkao,Li Wen-ming,Chao Xiao-juan,Yang Qian,Liu Pei-qing,Mao Zi-xu,Pi Rong-biao
Methylene blue (MB) can ameliorate behavioral, neurochemical, and neuropathological impairments in animal models of acute and chronic neurodegenerative disorders, but the underlying mechanism remains unclear. Myocyte enhancer factor 2 (MEF2D) is known to promote neuronal survival in several models, and several survival and death signals converge on MEF2D and regulate its activity. Here, we investigated the role of MEF2D in the neuroprotective effect of MB against glutamate-induced toxicity in HT22 neuronal cells. Our results showed that MB, event at less than 100 nM, improved the viability of HT22 cells exposed to 2 mM glutamate. MB attenuated the mitochondrial impairment and quenches the reactive oxygen species (ROS) induced by glutamate. Surprisingly, MB at 50–200 nM did not affect the Nrf2/HO-1 pathway, an important endogenous anti-oxidative system. Further study showed that MB increased the transcription and translation of MEF2D. In addition, MB upregulated the expression of mitochondrial NADH dehydrogenase 6 (ND6) in a MEF2D-dependent manner. Knockdown of MEF2D abolished both MB-medicated increase of ND6 and MB-induced neuroprotection against glutamate-induced toxicity. Moreover, we showed that MB promoted Akt function activity, suppressed GSK-3β activity, and increased MEF2D level in hippocampus of mice and HT22 cells. These findings for the first time demonstrate that MB protects HT22 neuronal cells against glutamate-induced cell death partially via the regulation of MEF2D-associated survival pathway.
研究领域:
神经科学
·
细胞生物学
·
药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACTA PHARMACOLOGICA SINICA
·
2025
·
IF 8.4
Lu Bin,Sun Yi-yun,Zhou Jia-hao,Chen Dan-ni,Guo Yue,Chen Yu-lu,Pan Cheng-hao,Chen Zheng-yang,He Qiao-jun,Yuan Meng,Cao Ji,Jiang Li,Yang Bo
Ubiquitin-specific protease 14 (USP14) is a crucial modulator of proteasomal function and cellular proteostasis, which plays an important role in the development and progression of various cancers including colorectal cancer (CRC). In this study we screened 670 covalent compounds using the in vitro Ub-AMC hydrolysis assay, and identified AKOS, initially a Chikungunya virus inhibitor, as a novel small-molecule inhibitor of USP14. We showed that AKOS inhibiting USP14 deubiquitinase activity with an IC 50 value of 0.98 μM. AKOS directly bound to USP14, covalently modifying the active-site cysteine residue (Cys 114 ), thereby effectively inhibiting its deubiquitinase activity. We demonstrated that inhibition of USP14 by AKOS might destabilize MEF2D, a critical substrate, resulting in downregulation of the expression and translation of ECM-related transcription factors such as ITGB4 . AKOS exhibited potent anti-cancer effects: the USP14 inhibitor significantly inhibited the proliferation and metastasis of CRC cells in vitro with IC 50 values of 9.88 and 16.57 μM, respectively, in SW620 cells and HCT116 cells. Intratumoral injection of AKOS (15, 30 mg/kg, every 5 days) effectively suppressed the tumor growth in HCT116 xenograft mouse models in vivo. Collectively, we demonstrate that AKOS is a promising chemical probe for targeting USP14 in CRC, offering a novel strategy for disrupting the malignant progression of CRC.
研究领域:
癌症生物学
·
生物化学
·
病毒学
·
药理学
·
细胞生物学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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