scholarly journals Palmitic Acid Treatment Decreases C2C12 Myoblasts Proliferation Rates through a G2 cell cycle shift

2008 ◽  
Vol 22 (S1) ◽  
Author(s):  
Jonathan M Peterson ◽  
Randy W Bryner ◽  
Stephen E Alway
Keyword(s):  
Cell Cycle ◽  
Palmitic Acid ◽  
Acid Treatment ◽  
C2c12 Myoblasts

scholarly journals MiR-96-5p Induced by Palmitic Acid Suppresses the Myogenic Differentiation of C2C12 Myoblasts by Targeting FHL1

2020 ◽  
Vol 21 (24) ◽  
pp. 9445
Author(s):  
Mai Thi Nguyen ◽  
Kyung-Ho Min ◽  
Wan Lee
Keyword(s):  
Cell Cycle ◽  
Palmitic Acid ◽  
Transcriptional Activation ◽  
Morphological Changes ◽  
Myogenic Differentiation ◽  
Saturated Fatty Acids ◽  
Critical Role ◽  
C2c12 Myoblasts ◽  
Multi Stage ◽  
Myogenic Factors

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.

scholarly journals Palmitic acid promotes resistin-induced insulin resistance and inflammation in SH-SY5Y human neuroblastoma

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hamza Amine ◽  
Yacir Benomar ◽  
Mohammed Taouis
Keyword(s):  
Insulin Resistance ◽  
Fatty Acids ◽  
Palmitic Acid ◽  
Lipid Rafts ◽  
Acid Treatment ◽  
Protective Action ◽  
Saturated Fatty Acids ◽  
Membrane Lipid ◽  
Human Neuroblastoma ◽  
Peripheral Tissues

AbstractSaturated fatty acids such as palmitic acid promote inflammation and insulin resistance in peripheral tissues, contrasting with the protective action of polyunsaturated fatty acids such docosahexaenoic acid. Palmitic acid effects have been in part attributed to its potential action through Toll-like receptor 4. Beside, resistin, an adipokine, also promotes inflammation and insulin resistance via TLR4. In the brain, palmitic acid and resistin trigger neuroinflammation and insulin resistance, but their link at the neuronal level is unknown. Using human SH-SY5Yneuroblastoma cell line we show that palmitic acid treatment impaired insulin-dependent Akt and Erk phosphorylation whereas DHA preserved insulin action. Palmitic acid up-regulated TLR4 as well as pro-inflammatory cytokines IL6 and TNFα contrasting with DHA effect. Similarly to palmitic acid, resistin treatment induced the up-regulation of IL6 and TNFα as well as NFκB activation. Importantly, palmitic acid potentiated the resistin-dependent NFkB activation whereas DHA abolished it. The recruitment of TLR4 to membrane lipid rafts was increased by palmitic acid treatment; this is concomitant with the augmentation of resistin-induced TLR4/MYD88/TIRAP complex formation mandatory for TLR4 signaling. In conclusion, palmitic acid increased TLR4 expression promoting resistin signaling through TLR4 up-regulation and its recruitment to membrane lipid rafts.

338. METHYL BINDING DOMAIN PROTEIN (MBD1) IN THE NUCLEUS OF THE MOUSE ZYGOTE

2010 ◽  
Vol 22 (9) ◽  
pp. 138
Author(s):  
Y. Li ◽  
X. L. Jin ◽  
C. O'Neill
Keyword(s):  
Cell Cycle ◽  
Acid Treatment ◽  
Metaphase Chromosomes ◽  
Methylated Dna ◽  
Stage Of Development ◽  
Genome Methylation ◽  
Mouse Zygote ◽  
Domain Protein ◽  
Proxy Measurement ◽  
Current Paradigm

MBD1 is one of five proteins which bind methylated DNA and regulate gene transcription. The binding of these proteins, particularly MBD1, is commonly used as a proxy measurement of global CpG methylation. Since methylation is reported to be highly dynamic during the first cell-cycle, with reported asymmetric global demethylation of the paternal and maternal genomes by the time of syngamy, we were interested to assess the pattern of staining of the MBD1 during this stage of development. A specific antibody to MBD1 was shown by Western analysis to detect in zygotes a protein of predicted mass. Using immunolocalization, however, we found no staining in pronuclei. Brief acid treatment (10min, 4M HCl) followed by immunolabelling revealed strong pronuclear MBD1 staining throughout the maturation of the zygote and on metaphase chromosomes, indicative of epitope masking under normal staining conditions. Upon unmasking by acid treatment zygotes collected fresh from the oviduct did not show consistent differences in MBD1 staining between the maternal or paternal chromosomes or pronuclei, but for those embryos produced by IVF we found more MBD1 staining in the male paternal pronucleus. Brief treatment with trypsin caused a marked loss of MBD1 staining and this treatment increased the extent of staining of 5-methylcytosine. These results show that MBD1 antigen persists on DNA after treatments normally used for the detection of 5-methylcytosine. MBD1 at least partially masks methylcytosine from immunological detection and the results therefore raise the possibility that the reported changes in genome methylation in the zygote are a consequence of the binding of MBD1. If MBD1 binding is truly a proxy for methylation, the persistence of high levels of MBD1 throughout the first cell-cycle questions the current paradigm of global demethylation during zygote maturation.

scholarly journals Alternative splicing of pericentrin contributes to cell cycle control in cardiomyocytes

2021 ◽  
Author(s):  
Jakob Steinfeldt ◽  
Robert Becker ◽  
Silvia Vergarajauregui ◽  
Felix B Engel
Keyword(s):  
Cell Cycle ◽  
Alternative Splicing ◽  
Cell Cycle Arrest ◽  
Cell Cycle Control ◽  
Ectopic Expression ◽  
Cell Number ◽  
Cardiomyocyte Proliferation ◽  
C2c12 Myoblasts ◽  
Cycle Arrest ◽  
Heterologous System

Induction of cardiomyocyte proliferation is a promising option to regenerate the heart. Thus, it is important to elucidate mechanisms that contribute to the cell cycle arrest of mammalian cardiomyocytes. Here, we assessed the contribution of the pericentrin (Pcnt) S isoform to the cell cycle arrest in postnatal cardiomyocytes. Immunofluorescence staining of Pcnt isoforms combined with siRNA-mediated depletion indicates that Pcnt S preferentially localizes to the nuclear envelope, while the Pcnt B isoform is enriched at centrosomes. This is further supported by the localization of ectopically expressed FLAG-tagged Pcnt S and Pcnt B in postnatal cardiomyocytes. Analysis of centriole configuration upon Pcnt depletion revealed that Pcnt B but not Pcnt S is required for centriole cohesion. Importantly, ectopic expression of Pcnt S induced centriole splitting in a heterologous system, ARPE-19 cells, and was sufficient to impair DNA synthesis in C2C12 myoblasts. Moreover, Pcnt S depletion enhanced serum-induced cell cycle re-entry in postnatal cardiomyocytes. Analysis of mitosis, binucleation rate, and cell number suggests that Pcnt S depletion promotes progression of postnatal cardiomyocytes through the cell cycle resulting in cell division. Collectively, our data indicate that alternative splicing of Pcnt contributes to the establishment of cardiomyocyte cell cycle arrest shortly after birth.

Distinct changes in intranuclear lamin A/C organization during myoblast differentiation

2001 ◽  
Vol 114 (22) ◽  
pp. 4001-4011 ◽  
Author(s):  
Bh. Muralikrishna ◽  
Jyotsna Dhawan ◽  
Nandini Rangaraj ◽  
Veena K. Parnaik
Keyword(s):  
Cell Cycle ◽  
Rna Splicing ◽  
Cell Types ◽  
Immunoblot Analysis ◽  
Splicing Factor ◽  
Myoblast Differentiation ◽  
Structural Reorganization ◽  
C2c12 Myoblasts ◽  
Muscle Cell Differentiation ◽  
And Migration

Intranuclear lamin foci or speckles have been observed in various cell types. In order to explore the possibility of changes in internal lamin organization during muscle differentiation, we have examined the appearance of A-type lamin speckles that associate with RNA splicing factor speckles in C2C12 myoblasts and myotubes. Lamin speckles were observed in dividing myoblasts but disappeared early during the course of differentiation in postmitotic myocytes, and were absent in myotubes and muscle fibers. However, no changes were seen in the typical peripheral organization of lamins A/C or B1 or in RNA splicing factor speckles. Lamin speckles were also absent in quiescent myoblasts but reappeared as cells were reactivated to enter the cell cycle. These changes were not observed in other quiescent cell types. Immunoblot analysis indicated that the abundance and migration of lamins A and C was not altered in differentiated myoblasts. When myotube or quiescent myoblast nuclei were extracted with nucleases and detergent, a uniformly stained internal lamina was revealed, indicating that lamins A/C were antigenically masked in these cells, probably owing to structural reorganization of the lamina during differentiation or quiescence. Our results suggest that muscle cell differentiation is accompanied by regulated rearrangements in the organization of the A-type lamins.

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