scholarly journals Role of MiR-325-3p in the Regulation of CFL2 and Myogenic Differentiation of C2C12 Myoblasts

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2725
Author(s):  
Mai Thi Nguyen ◽  
Wan Lee

Skeletal myogenesis is required to maintain muscle mass and integrity, and impaired myogenesis is causally linked to the etiology of muscle wasting. Recently, it was shown that excessive uptake of saturated fatty acids (SFA) plays a significant role in the pathogenesis of muscle wasting. Although microRNA (miRNA) is implicated in the regulation of myogenesis, the molecular mechanism whereby SFA-induced miRNAs impair myogenic differentiation remains largely unknown. Here, we investigated the regulatory roles of miR-325-3p on CFL2 expression and myogenic differentiation in C2C12 myoblasts. PA impeded myogenic differentiation, concomitantly suppressed CFL2 and induced miR-325-3p. Dual-luciferase analysis revealed that miR-325-3p directly targets the 3′UTR of CFL2, thereby suppressing the expression of CFL2, a crucial factor for actin dynamics. Transfection with miR-325-3p mimic resulted in the accumulation of actin filaments (F-actin) and nuclear Yes-associated protein (YAP) in myoblasts and promoted myoblast proliferation and cell cycle progression. Consequently, miR-325-3p mimic significantly attenuated the expressions of myogenic factors and thereby impaired the myogenic differentiation of myoblasts. The roles of miR-325-3p on CFL2 expression, F-actin modulation, and myogenic differentiation suggest a novel miRNA-mediated regulatory mechanism of myogenesis and PA-inducible miR-325-3p may be a critical mediator between obesity and muscle wasting.

2021 ◽  
Vol 22 (20) ◽  
pp. 10972
Author(s):  
Mai Thi Nguyen ◽  
Kyung-Ho Min ◽  
Wan Lee

MicroRNAs are known to play a critical role in skeletal myogenesis and maintenance, and cofilin-2 (CFL2) is necessary for actin cytoskeleton dynamics and myogenic differentiation. Nonetheless, target molecules and the modes of action of miRNAs, especially those responsible for the inhibitory mechanism on the myogenesis by saturated fatty acids (SFA) or obesity, still remain unclear. Here, we reported the role played by miR-429-3p on CFL2 expression, actin filament dynamics, myoblast proliferation, and myogenic differentiation in C2C12 cells. Palmitic acid (PA), the most abundant SFA in diet, inhibited the myogenic differentiation of myoblasts, accompanied by CFL2 reduction and miR-429-3p induction. Interestingly, miR-429-3p suppressed the expression of CFL2 by targeting the 3′UTR of CFL2 mRNA directly. Transfection of miR-429-3p mimic in myoblasts increased F-actin formation and augmented nuclear YAP level, thereby promoting cell cycle progression and myoblast proliferation. Moreover, miR-429-3p mimic drastically suppressed the expressions of myogenic factors, such as MyoD, MyoG, and MyHC, and impaired myogenic differentiation of C2C12 cells. Therefore, this study unveiled the crucial role of miR-429-3p in myogenic differentiation through the suppression of CFL2 and provided implications of SFA-induced miRNA in the regulation of actin dynamics and skeletal myogenesis.


2020 ◽  
Vol 21 (24) ◽  
pp. 9445
Author(s):  
Mai Thi Nguyen ◽  
Kyung-Ho Min ◽  
Wan Lee

Skeletal myogenesis is a multi-stage process that includes the cell cycle exit, myogenic transcriptional activation, and morphological changes to form multinucleated myofibers. Recent studies have shown that saturated fatty acids (SFA) and miRNAs play crucial roles in myogenesis and muscle homeostasis. Nevertheless, the target molecules and myogenic regulatory mechanisms of miRNAs are largely unknown, particularly when myogenesis is dysregulated by SFA deposition. This study investigated the critical role played by miR-96-5p on the myogenic differentiation in C2C12 myoblasts. Long-chain SFA palmitic acid (PA) significantly reduced FHL1 expression and inhibited the myogenic differentiation of C2C12 myoblasts but induced miR-96-5p expression. The knockdown of FHL1 by siRNA stimulated cell proliferation and inhibited myogenic differentiation of myoblasts. Interestingly, miR-96-5p suppressed FHL1 expression by directly targeting the 3’UTR of FHL1 mRNA. The transfection of an miR-96-5p mimic upregulated the expressions of cell cycle-related genes, such as PCNA, CCNB1, and CCND1, and increased myoblast proliferation. Moreover, the miR-96-5p mimic inhibited the expressions of myogenic factors, such as myoblast determination protein (MyoD), myogenin (MyoG), myocyte enhancer factor 2C (MEF2C), and myosin heavy chain (MyHC), and dramatically impeded differentiation and fusion of myoblasts. Overall, this study highlights the role of miR-96-5p in myogenesis via FHL1 suppression and suggests a novel regulatory mechanism for myogenesis mediated by miRNA in a background of obesity.


2019 ◽  
Vol 26 (11) ◽  
pp. 800-818
Author(s):  
Zujian Xiong ◽  
Xuejun Li ◽  
Qi Yang

Pituitary Tumor Transforming Gene (PTTG) of human is known as a checkpoint gene in the middle and late stages of mitosis, and is also a proto-oncogene that promotes cell cycle progression. In the nucleus, PTTG works as securin in controlling the mid-term segregation of sister chromatids. Overexpression of PTTG, entering the nucleus with the help of PBF in pituitary adenomas, participates in the regulation of cell cycle, interferes with DNA repair, induces genetic instability, transactivates FGF-2 and VEGF and promotes angiogenesis and tumor invasion. Simultaneously, overexpression of PTTG induces tumor cell senescence through the DNA damage pathway, making pituitary adenoma possessing the potential self-limiting ability. To elucidate the mechanism of PTTG in the regulation of pituitary adenomas, we focus on both the positive and negative function of PTTG and find out key factors interacted with PTTG in pituitary adenomas. Furthermore, we discuss other possible mechanisms correlate with PTTG in pituitary adenoma initiation and development and the potential value of PTTG in clinical treatment.


Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 995
Author(s):  
Xiaoyan Hou ◽  
Lijun Qiao ◽  
Ruijuan Liu ◽  
Xuechao Han ◽  
Weifang Zhang

Persistent infection of high-risk human papillomavirus (HR-HPV) plays a causal role in cervical cancer. Regulator of chromosome condensation 1 (RCC1) is a critical cell cycle regulator, which undergoes a few post-translational modifications including phosphorylation. Here, we showed that serine 11 (S11) of RCC1 was phosphorylated in HPV E7-expressing cells. However, S11 phosphorylation was not up-regulated by CDK1 in E7-expressing cells; instead, the PI3K/AKT/mTOR pathway promoted S11 phosphorylation. Knockdown of AKT or inhibition of the PI3K/AKT/mTOR pathway down-regulated phosphorylation of RCC1 S11. Furthermore, S11 phosphorylation occurred throughout the cell cycle, and reached its peak during the mitosis phase. Our previous data proved that RCC1 was necessary for the G1/S cell cycle progression, and in the present study we showed that the RCC1 mutant, in which S11 was mutated to alanine (S11A) to mimic non-phosphorylation status, lost the ability to facilitate G1/S transition in E7-expressing cells. Moreover, RCC1 S11 was phosphorylated by the PI3K/AKT/mTOR pathway in HPV-positive cervical cancer SiHa and HeLa cells. We conclude that S11 of RCC1 is phosphorylated by the PI3K/AKT/mTOR pathway and phosphorylation of RCC1 S11 facilitates the abrogation of G1 checkpoint in HPV E7-expressing cells. In short, our study explores a new role of RCC1 S11 phosphorylation in cell cycle regulation.


2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Yiming He ◽  
Mingxi Gan ◽  
Yanan Wang ◽  
Tong Huang ◽  
Jianbin Wang ◽  
...  

AbstractGrainyhead-like 1 (GRHL1) is a transcription factor involved in embryonic development. However, little is known about the biological functions of GRHL1 in cancer. In this study, we found that GRHL1 was upregulated in non-small cell lung cancer (NSCLC) and correlated with poor survival of patients. GRHL1 overexpression promoted the proliferation of NSCLC cells and knocking down GRHL1 inhibited the proliferation. RNA sequencing showed that a series of cell cycle-related genes were altered when knocking down GRHL1. We further demonstrated that GRHL1 could regulate the expression of cell cycle-related genes by binding to the promoter regions and increasing the transcription of the target genes. Besides, we also found that EGF stimulation could activate GRHL1 and promoted its nuclear translocation. We identified the key phosphorylation site at Ser76 on GRHL1 that is regulated by the EGFR-ERK axis. Taken together, these findings elucidate a new function of GRHL1 on regulating the cell cycle progression and point out the potential role of GRHL1 as a drug target in NSCLC.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anastasia Ricci ◽  
Sara Orazi ◽  
Federica Biancucci ◽  
Mauro Magnani ◽  
Michele Menotta

AbstractAtaxia telangiectasia (AT) is a rare genetic neurodegenerative disease. To date, there is no available cure for the illness, but the use of glucocorticoids has been shown to alleviate the neurological symptoms associated with AT. While studying the effects of dexamethasone (dex) in AT fibroblasts, by chance we observed that the nucleoplasmic Lamin A/C was affected by the drug. In addition to the structural roles of A-type lamins, Lamin A/C has been shown to play a role in the regulation of gene expression and cell cycle progression, and alterations in the LMNA gene is cause of human diseases called laminopathies. Dex was found to improve the nucleoplasmic accumulation of soluble Lamin A/C and was capable of managing the large chromatin Lamin A/C scaffolds contained complex, thus regulating epigenetics in treated cells. In addition, dex modified the interactions of Lamin A/C with its direct partners lamin associated polypeptide (LAP) 2a, Retinoblastoma 1 (pRB) and E2F Transcription Factor 1 (E2F1), regulating local gene expression dependent on E2F1. These effects were differentially observed in both AT and wild type (WT) cells. To our knowledge, this is the first reported evidence of the role of dex in Lamin A/C dynamics in AT cells, and may represent a new area of research regarding the effects of glucocorticoids on AT. Moreover, future investigations could also be extended to healthy subjects or to other pathologies such as laminopathies since glucocorticoids may have other important effects in these contexts as well.


1991 ◽  
Vol 11 (12) ◽  
pp. 6177-6184
Author(s):  
B Ducommun ◽  
P Brambilla ◽  
G Draetta

suc1+ encodes an essential cell cycle regulator of the fission yeast Schizosaccharomyces pombe. Its product, a 13-kDa protein, interacts with the Cdc2 protein kinase. Both positive and negative effects on cell cycle progression have been attributed to Suc1. To date, the exact mechanisms and the physiological role of the interaction between Suc1 and Cdc2 remain unclear. Here we have studied the molecular basis of this association. We show that Cdc2 can bind Suc1 or its mammalian homolog directly in the absence of any additional protein component. Using an alanine scanning mutagenesis method, we analyzed the interaction between Cdc2 and Suc1. We show that the integrity of several domains on the Cdc2 protein, including sites directly involved in catalytic activity, is required for binding to Suc1. Furthermore, Cdc2 mutant proteins unable to bind Suc1 (but able to bind cyclins) are nonfunctional when overexpressed in S. pombe, indicating that a specific interaction with Suc1 is required for Cdc2 function.


PLoS ONE ◽  
2018 ◽  
Vol 13 (11) ◽  
pp. e0208022 ◽  
Author(s):  
Changfu Yao ◽  
Chao Wang ◽  
Yeran Li ◽  
Michael Zavortink ◽  
Vincent Archambault ◽  
...  

2012 ◽  
pp. 235-243 ◽  
Author(s):  
Norman Balcazar Morales ◽  
Cecilia Aguilar de Plata

Growth factors, insulin signaling and nutrients are important regulators of β-cell mass and function. The events linking these signals to regulation of β-cell mass are not completely understood. Recent findings indicate that mTOR pathway integrates signals from growth factors and nutrients with transcription, translation, cell size, cytoskeleton remodeling and mitochondrial metabolism. mTOR is a part of two distinct complexes; mTORC1 and mTORC2. The mammalian TORC1 is sensitive to rapamycin and contains Raptor, deptor, PRAS40 and the G protein β-subunit-like protein (GβL). mTORC1 activates key regulators of protein translation; ribosomal S6 kinase (S6K) and eukaryote initiation factor 4E-binding protein 1. This review summarizes current findings about the role of AKT/mTORC1 signaling in regulation of pancreatic β cell mass and proliferation. mTORC1 is a major regulator of β-cell cycle progression by modulation of cyclins D2, D3 and cdk4/cyclin D activity. These studies uncovered key novel pathways controlling cell cycle progression in β-cells in vivo. This information can be used to develop alternative approaches to expand β-cell mass in vivo and in vitro without the risk of oncogenic transformation. The acquisition of such knowledge is critical for the design of improved therapeutic strategies for the treatment and cure of diabetes as well as to understand the effects of mTOR inhibitors in β-cell function.


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