scholarly journals Coupled Transcriptional and Translational Control of Cyclin-Dependent Kinase Inhibitor p18INK4cExpression during Myogenesis

1998 ◽  
Vol 18 (4) ◽  
pp. 2334-2343 ◽  
Author(s):  
Dawn E. Phelps ◽  
Kuang-Ming Hsiao ◽  
Yan Li ◽  
Nanpin Hu ◽  
David S. Franklin ◽  
...  
Keyword(s):  
Translational Control ◽  
Kinase Inhibitor ◽  
Myogenic Differentiation ◽  
Protein A ◽  
Terminal Differentiation ◽  
C2c12 Cells ◽  
Cdk Inhibitor ◽  
Cyclin Dependent Kinase ◽  
C2c12 Myoblasts ◽  
Exon 1

ABSTRACT Terminal differentiation of many cell types involves permanent withdrawal from the cell division cycle. The p18 INK4c protein, a member of the p16/INK4 cyclin-dependent kinase (CDK) inhibitor family, is induced more than 50-fold during myogenic differentiation of mouse C2C12 myoblasts to become the predominant CDK inhibitor complexed with CDK4 and CDK6 in terminally differentiated myotubes. We have found that the p18 INK4c gene expresses two mRNA transcripts—a 2.4-kb transcript, p18(L), and a 1.2-kb transcript, p18(S). In proliferating C2C12 myoblasts, only the larger p18(L) transcript is expressed from an upstream promoter. As C2C12 cells are induced to differentiate into permanently arrested myotubes, the abundance of the p18(L) transcript decreases. The smaller p18(S) transcript expressed from a downstream promoter becomes detectable by 12 h postinduction and is the predominant transcript expressed in terminally differentiated myotubes. Both transcripts contain coding exons 2 and 3, but p18(L) uniquely contains an additional noncoding 1.2-kb exon, exon 1, corresponding exclusively to the 5′ untranslated region (5′ UTR). The expression pattern of the shorter p18(S) transcript, but not that of the longer p18(L) transcript, correlates with terminal differentiation of muscle, lung, liver, thymus, and eye lens cells during mouse embryo development. The presence of the long 5′ UTR in exon 1 attenuated the translation of p18(L) transcript, while its absence from the shorter p18(S) transcript resulted in significantly more efficient translation of the p18 protein. Our results demonstrate that during terminal muscle cell differentiation, induction of the p18 protein is regulated by promoter switching coupled with translational control.

Interleukin-6 promotes myogenic differentiation of mouse skeletal muscle cells: role of the STAT3 pathway

2013 ◽  
Vol 304 (2) ◽  
pp. C128-C136 ◽  
Author(s):  
Miriam Hoene ◽  
Heike Runge ◽  
Hans Ulrich Häring ◽  
Erwin D. Schleicher ◽  
Cora Weigert
Keyword(s):  
Skeletal Muscle ◽  
Mrna Expression ◽  
Myogenic Differentiation ◽  
Muscle Cells ◽  
C2c12 Cells ◽  
Skeletal Muscle Cells ◽  
Wild Type ◽  
C2c12 Myoblasts ◽  
Sequence Of Events ◽  
Primary Mouse

Myogenic differentiation of skeletal muscle cells is characterized by a sequence of events that include activation of signal transducer and activator of transcription 3 (STAT3) and enhanced expression of its target gene Socs3. Autocrine effects of IL-6 may contribute to the activation of the STAT3-Socs3 cascade and thus to myogenic differentiation. The importance of IL-6 and STAT3 for the differentiation process was studied in C2C12 cells and in primary mouse wild-type and IL-6−/− skeletal muscle cells. In differentiating C2C12 myoblasts, the upregulation of IL-6 mRNA expression and protein secretion started after increased phosphorylation of STAT3 on tyrosine 705 and increased mRNA expression of Socs3 was observed. Knockdown of STAT3 and IL-6 mRNA in differentiating C2C12 myoblasts impaired the expression of the myogenic markers myogenin and MyHC IIb and subsequently myotube fusion. However, the knockdown of IL-6 did not prevent the induction of STAT3 tyrosine phosphorylation. The IL-6-independent activation of STAT3 was verified in differentiating primary IL-6−/− myoblasts. The phosphorylation of STAT3 and the expression levels of STAT3, Socs3, and myogenin during differentiation were comparable in the primary myoblasts independent of the genotype. However, IL-6−/− cells failed to induce MyHC IIb expression to the same level as in wild-type cells and showed reduced myotube formation. Supplementation of IL-6 could partially restore the fusion of IL-6−/− cells. These data demonstrate that IL-6 depletion during myogenic differentiation does not reduce the activation of the STAT3-Socs3 cascade, while IL-6 and STAT3 are both necessary to promote myotube fusion.

scholarly journals Periodic Expression of the Cyclin-dependent Kinase Inhibitor p57Kip2 in Trophoblast Giant Cells Defines a G2-like Gap Phase of the Endocycle

2000 ◽  
Vol 11 (3) ◽  
pp. 1037-1045 ◽  
Author(s):  
Naka Hattori ◽  
Tyler C. Davies ◽  
Lynn Anson-Cartwright ◽  
James C. Cross
Keyword(s):  
Dna Replication ◽  
Protein Targeting ◽  
Kinase Inhibitor ◽  
Phosphorylation Site ◽  
Giant Cells ◽  
S Phase ◽  
Stable Form ◽  
Cdk Inhibitor ◽  
Cyclin Dependent Kinase ◽  
Trophoblast Giant Cells

Endoreduplication is an unusual form of cell cycle in which rounds of DNA synthesis repeat in the absence of intervening mitoses. How G1/S cyclin-dependent kinase (Cdk) activity is regulated during the mammalian endocycle is poorly understood. We show here that expression of the G1/S Cdk inhibitor p57Kip2 is induced coincidentally with the transition to the endocycle in trophoblast giant cells.Kip2 mRNA is constitutively expressed during subsequent endocycles, but the protein level fluctuates. In trophoblast giant cells synchronized for the first few endocycles, the p57Kip2 protein accumulates only at the end of S-phase and then rapidly disappears a few hours before the onset of the next S-phase. The protein becomes stabilized by mutation of a C-terminal Cdk phosphorylation site. As a consequence, introduction of this stable form of p57Kip2 into giant cells blocks S-phase entry. These data imply that p57Kip2 is subject to phosphorylation-dependent turnover. Surprisingly, although this occurs in endoreduplicating giant cells, p57Kip2 is stable when ectopically expressed in proliferating trophoblast cells, indicating that these cells lack the mechanism for protein targeting and/or degradation. These data show that the appearance of p57Kip2punctuates the completion of DNA replication, whereas its turnover is subsequently required to initiate the next round of endoreduplication in trophoblast giant cells. Cyclical expression of a Cdk inhibitor, by terminating G1/S Cdk activity, may help promote the resetting of DNA replication machinery.

scholarly journals Simultaneous overexpression of Oct4 and Nanog abrogates terminal myogenesis

2009 ◽  
Vol 297 (1) ◽  
pp. C43-C54 ◽  
Author(s):  
Kuan Chih Lang ◽  
I. Hsuan Lin ◽  
Han Fang Teng ◽  
Yi Cheng Huang ◽  
Chung Leung Li ◽  
...  
Keyword(s):  
Myogenic Differentiation ◽  
Severe Combined Immunodeficiency ◽  
Embryonic Stem ◽  
Terminal Differentiation ◽  
C2c12 Cells ◽  
Es Cell ◽  
Nonobese Diabetic ◽  
Nanog Expression ◽  
Myogenic Markers ◽  
Lineage Specific Genes

Oct4 and Nanog are two embryonic stem (ES) cell-specific transcription factors that play critical roles in the maintenance of ES cell pluripotency. In this study, we investigated the effects of Oct4 and Nanog expression on the differentiation state of myogenic cells, which is sustained by a strong positive feedback loop. Oct4 and Nanog, either independently or simultaneously, were overexpressed in C2C12 myoblasts, and the expression of myogenic lineage-specific genes and terminal differentiation was observed by RT-PCR. Overexpression of Oct4 in C2C12 cultures repressed, while exogenous Nanog did not significantly alter C2C12 terminal differentiation. The expression of Pax7 was reduced in all Oct4-overexpressing myoblasts, and we identified a major Oct4-binding site in the Pax7 promoter. Simultaneous expression of Oct4 and Nanog in myoblasts inhibited the formation of myotubes, concomitant with a reduction in the endogenous levels of hallmark myogenic markers. Furthermore, overexpression of Oct4 and Nanog induced the expression of their endogenous counterparts along with the expression of Sox2. Using mammalian two-hybrid assays, we confirmed that Oct4 functions as a transcriptional repressor whereas Nanog functions as a transcriptional activator during muscle terminal differentiation. Importantly, in nonobese diabetic (NOD) severe combined immunodeficiency (SCID) mice, the pluripotency of C2C12 cells was conferred by overexpression of Oct4 and Nanog. These results suggest that Oct4 in cooperation with Nanog strongly suppresses the myogenic differentiation program and promotes pluripotency in myoblasts.

scholarly journals Inhibition of Cyclin-Dependent Kinases Improves CA1 Neuronal Survival and Behavioral Performance after Global Ischemia in the Rat

2002 ◽  
Vol 22 (2) ◽  
pp. 171-182 ◽  
Author(s):  
Fuhu Wang ◽  
Dale Corbett ◽  
Hitoshi Osuga ◽  
Sachiko Osuga ◽  
Joh-E Ikeda ◽  
...  
Keyword(s):  
Kinase Inhibitor ◽  
Core Body Temperature ◽  
Protein A ◽  
Extended Period ◽  
Global Ischemia ◽  
Cyclin Dependent Kinase ◽  
Kinase Inhibition ◽  
Cyclin Dependent Kinases

Increasing evidence suggests that cyclin-dependent kinases participate in neuronal death induced by multiple stresses in vitro. However, their role in cell death paradigms in vivo is not well characterized. Accordingly, the authors examined whether cyclin-dependent kinase inhibition resulted in functionally relevant and sustained neuroprotection in a model of global ischemia. Intracerebroventricular administration of the cyclin-dependent kinase inhibitor flavopiridol, immediately or at 4 hours postreperfusion after a global insult, reduced injury in the CA1 of the hippocampus when examined 7 days after reperfusion. No significant protection was observed when flavopiridol was administered 8 hours after reperfusion. The tumor-suppressor retinoblastoma protein, a substrate of cyclin-dependent kinase, was phosphorylated on a cyclin-dependent kinase consensus site after the global insult; this phosphorylation was inhibited by flavopiridol administration. Importantly, flavopiridol had no effect on core body temperature, suggesting that the mechanism of neuroprotection was through cyclin-dependent kinase inhibition but not through hypothermia. Furthermore, inhibition of cyclin-dependent kinases improved spatial learning behavior as assessed by the Morris water maze 7 to 9 days after reperfusion. However, the histologic protection observed at day 7 was absent 28 days after reperfusion. These results indicate that cyclin-dependent kinase inhibition provides an extended period of morphologic and functional neuroprotection that may allow time for other neuroprotective modalities to be introduced.

scholarly journals Ganoderma microsporum immunomodulatory protein, GMI, promotes C2C12 myoblast differentiation in vitro via upregulation of Tid1 and STAT3 acetylation

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244791
Author(s):  
Wan-Huai Teo ◽  
Jeng-Fan Lo ◽  
Yu-Ning Fan ◽  
Chih-Yang Huang ◽  
Tung-Fu Huang
Keyword(s):  
Myogenic Differentiation ◽  
Atp Synthesis ◽  
C2c12 Cells ◽  
Myoblast Differentiation ◽  
C2c12 Myoblast ◽  
Muscle Loss ◽  
C2c12 Myoblasts ◽  
Immunomodulatory Protein ◽  
Pre Treatment

Ageing and chronic diseases lead to muscle loss and impair the regeneration of skeletal muscle. Thus, it’s crucial to seek for effective intervention to improve the muscle regeneration. Tid1, a mitochondrial co-chaperone, is important to maintain mitochondrial membrane potential and ATP synthesis. Previously, we demonstrated that mice with skeletal muscular specific Tid1 deficiency displayed muscular dystrophy and postnatal lethality. Tid1 can interact with STAT3 protein, which also plays an important role during myogenesis. In this study, we used GMI, immunomodulatory protein of Ganoderma microsporum, as an inducer in C2C12 myoblast differentiation. We observed that GMI pretreatment promoted the myogenic differentiation of C2C12 myoblasts. We also showed that the upregulation of mitochondria protein Tid1 with the GMI pre-treatment promoted myogenic differentiation ability of C2C12 cells. Strikingly, we observed the concomitant elevation of STAT3 acetylation (Ac-STAT3) during C2C12 myogenesis. Our study suggests that GMI promotes the myogenic differentiation through the activation of Tid1 and Ac-STAT3.

scholarly journals Biomechanical signals upregulate myogenic gene induction in the presence or absence of inflammation

2007 ◽  
Vol 293 (1) ◽  
pp. C267-C276 ◽  
Author(s):  
Ravi Chandran ◽  
Thomas J. Knobloch ◽  
Mirela Anghelina ◽  
Sudha Agarwal
Keyword(s):  
Cell Differentiation ◽  
Muscle Cell ◽  
Kinase Inhibitor ◽  
Cell Damage ◽  
Myogenic Differentiation ◽  
C2c12 Cell ◽  
Gene Induction ◽  
C2c12 Cells ◽  
Proinflammatory Mediators ◽  
Tnf Α

Inflammation of the muscle invariably leads to muscle cell damage and impaired regeneration. Biomechanical signals play a vital role in the regulation of myogenesis in healthy and inflamed muscle. We hypothesized that biomechanical signals counteract the actions of proinflammatory mediators and upregulate the basic helix-loop-helix and MADS box transcription enhancer factor 2 (MEF2) families of transcription factors, leading to increased myogenesis in inflamed muscle cells. For this purpose, C2C12 cells plated on collagenized silastic membranes were subjected to equibiaxial cyclic tensile strain (CTS) in the presence or absence of TNF-α, and the myogenic gene induction was examined over a period of 72 h. Exposure of cells to CTS resulted in a significant upregulation of mRNA expressions and synthesis of myogenic regulatory factors, MYOD1, myogenin (MYOG), MEF2A, and cyclin-dependent kinase inhibitor 1A (CDKN1A; p21) as well as muscle structural proteins like myosin heavy chain (MYHC) isoforms (MYH1, MYH2, and MYH4) and α-tropomyosin (TPM1), eventually leading to an increase in myotube formation. Contrarily, TNF-α suppressed the expression of all of the above differentiation-inducing factors in C2C12 cells. Further results revealed that simultaneous exposure of C2C12 cells to CTS and TNF-α abrogated the TNF-α-mediated downregulation of myogenic differentiation. In fact, the mRNA expression and protein synthesis of all myogenic factors ( Myod1, Myog, Mef2a, Cdkn1a, Myh1, Myh2, Myh4, and Tpm1) were increased in stretched C2C12 cells despite the sustained presence of TNF-α. These results demonstrate that mechanotransduction regulates multiple signaling molecules involved in C2C12 cell differentiation. On one hand, these signals are potent transducers of myotube phenotype in myoblasts; on the other, these signals counteract catabolic actions of proinflammatory cytokines like TNF-α and allow the expression of myogenic genes to upregulate muscle cell differentiation.

scholarly journals p27Kip1 Acts Downstream of N-Cadherin-mediated Cell Adhesion to Promote Myogenesis beyond Cell Cycle Regulation

2005 ◽  
Vol 16 (3) ◽  
pp. 1469-1480 ◽  
Author(s):  
Graziella Messina ◽  
Cristiana Blasi ◽  
Severina Anna La Rocca ◽  
Monica Pompili ◽  
Attilio Calconi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Myogenic Differentiation ◽  
Cell Cycle Control ◽  
C2c12 Cell ◽  
Terminal Differentiation ◽  
Active Role ◽  
C2c12 Cells ◽  
Low Density

It is widely acknowledged that cultured myoblasts can not differentiate at very low density. Here we analyzed the mechanism through which cell density influences myogenic differentiation in vitro. By comparing the behavior of C2C12 myoblasts at opposite cell densities, we found that, when cells are sparse, failure to undergo terminal differentiation is independent from cell cycle control and reflects the lack of p27Kip1 and MyoD in proliferating myoblasts. We show that inhibition of p27Kip1 expression impairs C2C12 cell differentiation at high density, while exogenous p27Kip1 allows low-density cultured C2C12 cells to enter the differentiative program by regulating MyoD levels in undifferentiated myoblasts. We also demonstrate that the early induction of p27Kip1 is a critical step of the N-cadherin-dependent signaling involved in myogenesis. Overall, our data support an active role of p27Kip1 in the decision of myoblasts to commit to terminal differentiation, distinct from the regulation of cell proliferation, and identify a pathway that, reasonably, operates in vivo during myogenesis and might be part of the phenomenon known as “community effect”.

scholarly journals Alsterpaullone, a Cyclin-Dependent Kinase Inhibitor, Mediated Toxicity in HeLa Cells through Apoptosis-Inducing Effect

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Chunying Cui ◽  
Yuji Wang ◽  
Yaonan Wang ◽  
Ming Zhao ◽  
Shiqi Peng
Keyword(s):  
Cell Cycle ◽  
Hela Cells ◽  
Cell Cycle Progression ◽  
Caspase 3 ◽  
Kinase Inhibitor ◽  
Cdk Inhibitor ◽  
Cyclin Dependent Kinase ◽  
Cycle Progression ◽  
Cyclin Dependent Kinase Inhibitor ◽  
Dose Dependent

Alsterpaullone, a small molecule cyclin-dependent kinase (CDK) inhibitor, regulates the cell cycle progression. Beyond death-inducing properties, we identified the effect of alsterpaullone on cycle procedure and apoptosis of HeLa cell. It was found that alsterpaullone inhibited HeLa cells in a time-dependent (0–72 h) and dose-dependent (0–30 μM) manner. In the presence of alsterpaullone, HeLa cells were arrested in G2/M prior to undergoing apoptosis via a mechanism that is involved in the regulation of various antiapoptotic genes, DNA-repair, transcription, and cell cycle progression. Compared to controls, alsterpaullone effectively prevented HeLa cells from entering S-phase. These potential therapeutic efficacies could be correlated with the activation of caspase-3.

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