Myogenic differentiation during regrowth of atrophied skeletal muscle is associated with inactivation of GSK-3β

2007 ◽  
Vol 292 (5) ◽  
pp. C1636-C1644 ◽  
Author(s):  
Jos L. J. van der Velden ◽  
Ramon C. J. Langen ◽  
Marco C. J. M. Kelders ◽  
Jodil Willems ◽  
Emiel F. M. Wouters ◽  
...  
Keyword(s):  
Muscle Atrophy ◽  
Glycogen Synthase ◽  
Myogenic Differentiation ◽  
Hindlimb Suspension ◽  
Akt Phosphorylation ◽  
Proliferation And Differentiation ◽  
Igf I ◽  
Myoblast Proliferation ◽  
Gsk 3Β ◽  
First Time

Muscle atrophy contributes to morbidity and mortality in aging and chronic disease, emphasizing the need to gain understanding of the mechanisms involved in muscle atrophy and (re)growth. We hypothesized that the magnitude of muscle regrowth during recovery from atrophy determines whether myonuclear accretion and myogenic differentiation are required and that insulin-like growth factor (IGF)-I/Akt/glycogen synthase kinase (GSK)-3β signaling differs between regrowth responses. To address this hypothesis we subjected mice to hindlimb suspension (HS) to induce atrophy of soleus (−40%) and plantaris (−27%) muscle. Reloading-induced muscle regrowth was complete after 14 days and involved an increase in IGF-IEa mRNA expression that coincided with Akt phosphorylation in both muscles. In contrast, phosphorylation and inactivation of GSK-3β were observed during soleus regrowth only. Furthermore, soleus but not plantaris regrowth involved muscle regeneration based on a transient increase in expression of histone 3.2 and myosin heavy chain-perinatal, which are markers of myoblast proliferation and differentiation, and a strong induction of muscle regulatory factor (MRF) expression. Experiments in cultured muscle cells showed that IGF-I-induced MRF expression is facilitated by inactivation of GSK-3β and selectively occurs in the myoblast population. This study suggests that induction of IGF-I expression and Akt phosphorylation during recovery from muscle atrophy is independent of the magnitude of muscle regrowth. Moreover, our data demonstrate for the first time that the regenerative response characterized by myoblast proliferation, differentiation, and increased MRF expression in recovering muscle is associated with the magnitude of regrowth and may be regulated by inactivation of GSK-3β.

Inhibition of glycogen synthase kinase-3β activity is sufficient to stimulate myogenic differentiation

2006 ◽  
Vol 290 (2) ◽  
pp. C453-C462 ◽  
Author(s):  
Jos L. J. van der Velden ◽  
Ramon C. J. Langen ◽  
Marco C. J. M. Kelders ◽  
Emiel F. M. Wouters ◽  
Yvonne M. W. Janssen-Heininger ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Glycogen Synthase ◽  
Muscle Growth ◽  
Glycogen Synthase Kinase ◽  
Skeletal Muscle Atrophy ◽  
Glycogen Synthase Kinase 3Β ◽  
Igf I ◽  
Gsk 3Β ◽  
Stimulation Of

Skeletal muscle atrophy is a prominent and disabling feature of chronic wasting diseases. Prevention or reversal of muscle atrophy by administration of skeletal muscle growth (hypertrophy)-stimulating agents such as insulin-like growth factor I (IGF-I) could be an important therapeutic strategy in these diseases. To elucidate the IGF-I signal transduction responsible for muscle formation (myogenesis) during muscle growth and regeneration, we applied IGF-I to differentiating C2C12 myoblasts and evaluated the effects on phosphatidylinositol 3-kinase (PI3K)/Akt/glycogen synthase kinase-3β (GSK-3β) signaling and myogenesis. IGF-I caused phosphorylation and inactivation of GSK-3β activity via signaling through the PI3K/Akt pathway. We assessed whether pharmacological inhibition of GSK-3β with lithium chloride (LiCl) was sufficient to stimulate myogenesis. Addition of IGF-I or LiCl stimulated myogenesis, evidenced by increased myotube formation, muscle creatine kinase (MCK) activity, and troponin I (TnI) promoter transactivation during differentiation. Moreover, mRNAs encoding MyoD, Myf-5, myogenin, TnI-slow, TnI-fast, MCK, and myoglobin were upregulated in myoblasts differentiated in the presence of IGF-I or LiCl. Importantly, blockade of GSK-3β inhibition abrogated IGF-I- but not LiCl-dependent stimulation of myogenic mRNA accumulation, suggesting that the promyogenic effects of IGF-I require GSK-3β inactivation and revealing an important negative regulatory role for GSK-3β in myogenesis. Therefore, this study identifies GSK-3β as a potential target for pharmacological stimulation of muscle growth.

Glycogen synthase kinase-3β is required for the induction of skeletal muscle atrophy

2011 ◽  
Vol 301 (5) ◽  
pp. C995-C1007 ◽  
Author(s):  
Koen J. P. Verhees ◽  
Annemie M. W. J. Schols ◽  
Marco C. J. M. Kelders ◽  
Céline M. H. Op den Kamp ◽  
Jos L. J. van der Velden ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Glycogen Synthase ◽  
Akt Signaling ◽  
Myofibrillar Protein ◽  
Skeletal Muscle Atrophy ◽  
Glycogen Synthase Kinase 3Β ◽  
Protein Loss ◽  
Igf I ◽  
Gsk 3Β

Skeletal muscle atrophy commonly occurs in acute and chronic disease. The expression of the muscle-specific E3 ligases atrogin-1 (MAFbx) and muscle RING finger 1 (MuRF1) is induced by atrophy stimuli such as glucocorticoids or absence of IGF-I/insulin and subsequent Akt signaling. We investigated whether glycogen synthase kinase-3β (GSK-3β), a downstream molecule in IGF-I/Akt signaling, is required for basal and atrophy stimulus-induced expression of atrogin-1 and MuRF1, and myofibrillar protein loss in C2C12 skeletal myotubes. Abrogation of basal IGF-I signaling, using LY294002, resulted in a prominent induction of atrogin-1 and MuRF1 mRNA and was accompanied by a loss of myosin heavy chain fast (MyHC-f) and myosin light chains 1 (MyLC-1) and -3 (MyLC-3). The synthetic glucocorticoid dexamethasone (Dex) also induced the expression of both atrogenes and likewise resulted in the loss of myosin protein abundance. Genetic ablation of GSK-3β using small interfering RNA resulted in specific sparing of MyHC-f, MyLC-1, and MyLC-3 protein levels after Dex treatment or impaired IGF-I/Akt signaling. Interestingly, loss of endogenous GSK-3β suppressed both basal and atrophy stimulus-induced atrogin-1 and MuRF1 expression, whereas pharmacological GSK-3β inhibition, using CHIR99021 or LiCl, only reduced atrogin-1 mRNA levels in response to LY294002 or Dex. In conclusion, our data reveal that myotube atrophy and myofibrillar protein loss are GSK-3β dependent, and demonstrate for the first time that basal and atrophy stimulus-induced atrogin-1 mRNA expression requires GSK-3β enzymatic activity, whereas MuRF1 expression depends solely on the physical presence of GSK-3β.

GSK-3β negatively regulates skeletal myotube hypertrophy

2002 ◽  
Vol 283 (2) ◽  
pp. C545-C551 ◽  
Author(s):  
Dharmesh R. Vyas ◽  
Espen E. Spangenburg ◽  
Tsghe W. Abraha ◽  
Thomas E. Childs ◽  
Frank W. Booth
Keyword(s):  
Kinase Activity ◽  
Glycogen Synthase ◽  
Gene Activity ◽  
Luciferase Reporter ◽  
Activated T Cells ◽  
Reporter Activity ◽  
Igf I ◽  
Nfat Activation ◽  
Gsk 3Β ◽  
Myotube Hypertrophy

To determine whether changes in glycogen synthase kinase-3β (GSK-3β) phosphorylation contribute to muscle hypertrophy, we delineated the effects of GSK-3β activity on C2C12 myotube size. We also examined possible insulin-like growth factor I (IGF-I) signaling of NFAT (nuclear factors of activated T cells)-inducible gene activity and possible modulation of NFAT activation by GSK-3β. Application of IGF-I (250 ng/ml) or LiCl (10 mM) alone (i.e., both inhibit GSK-3β activity) increased the area of C2C12 myotubes by 80 and 85%, respectively. The application of IGF-I (250 ng/ml) elevated GSK-3β phosphorylation and reduced GSK-3β kinase activity by ∼800% and ∼25%, respectively. LY-294002 (100 μM) and wortmannin (150 μM), specific inhibitors of phosphatidylinositol 3′-kinase, attenuated IGF-I-induced GSK-3β phosphorylation by 67 and 92%, respectively. IGF-I suppressed the kinase activity of GSK-3β. IGF-I (250 ng/ml), but not LiCl (10 mM), induced an increase in NFAT-activated luciferase reporter activity. Cotransfection of a constitutively active GSK-3β (cGSK-3β) inhibited the induction by IGF-I of NFAT-inducible reporter activity. LiCl, which inhibits GSK-3β, removed the block by cGSK-3β on IGF-I-inducible NFAT-responsive reporter gene activity. These data suggest that the IGF-I-induced increase in skeletal myotube size is signaled, in part, through the inhibition of GSK-3β.

scholarly journals cGMP-dependent protein kinase II determines β-catenin accumulation that is essential for uterine decidualization in mice

2019 ◽  
Vol 317 (6) ◽  
pp. C1115-C1127
Author(s):  
Yang Zhang ◽  
Lu Yan ◽  
Jiali Liu ◽  
Sheng Cui ◽  
Jingtao Qiu
Keyword(s):  
Protein Kinase ◽  
Stromal Cells ◽  
Glycogen Synthase ◽  
Regulatory Function ◽  
Dependent Protein Kinase ◽  
Cgmp Dependent Protein Kinase ◽  
Decidual Cells ◽  
Proliferation And Differentiation ◽  
Dependent Protein ◽  
Gsk 3Β

In the early phase of pregnancy, decidualization is an indispensable event after mammal embryo implantation, accompanied by proliferation and differentiation of uterine stromal cells. Type II cGMP-dependent protein kinase (Prkg2) belongs to the family of serine/threonine kinase, which plays multiple roles in cellular signaling pathways to control proliferation and differentiation. However, the regulatory function and molecular mechanism of Prkg2 in decidualization are still unknown. In this study, we show that Prkg2 has a gradually increased expression pattern during peri-implantation and artificial decidualization, and the expression of Prkg2 is induced by estrogen and progesterone in the ovariectomized mouse uteri and primary cultured uterine stromal cells, the process of which is blocked by treating with estrogen receptor (ER) antagonist (ICI-182,780) and progesterone receptor (PR) antagonist (RU-486). Inhibition of Prkg2 activity by HA-100 promotes uterine stromal cell proliferation but compromises decidualization with decreased expression of prolactin family 8, subfamily a, member 2. In addition, the functional regulation of decidualization by Prkg2 is accomplished by its induced phosphorylation of glycogen synthase kinase-3β (GSK-3β) at serine-9, which results in accumulation of β-catenin in the decidual cells. Taken together, our findings demonstrate that estrogen and progesterone upregulate the expression of Prkg2 in uterine stromal cells depending on ER and PR; Prkg2 promotes phosphorylation of GSK-3β at serine-9 and inactivates it, leading to the accumulation of β-catenin and promoting the process of decidualization. In addition to revealing the regulatory mechanism of Prkg2 that ensures the success of uterine decidualization, our findings will contribute to the understanding in the maintenance of early pregnancy.

scholarly journals JAK1–STAT1–STAT3, a key pathway promoting proliferation and preventing premature differentiation of myoblasts

2007 ◽  
Vol 179 (1) ◽  
pp. 129-138 ◽  
Author(s):  
Luguo Sun ◽  
Kewei Ma ◽  
Haixia Wang ◽  
Fang Xiao ◽  
Yan Gao ◽  
...  
Keyword(s):  
Myogenic Differentiation ◽  
Muscle Growth ◽  
Janus Kinase ◽  
Myoblast Differentiation ◽  
Muscle Stem Cell ◽  
Janus Kinase 1 ◽  
Binding Factor ◽  
Proliferation And Differentiation ◽  
Myoblast Proliferation ◽  
Concomitant Reduction

Skeletal muscle stem cell–derived myoblasts are mainly responsible for postnatal muscle growth and injury-induced muscle regeneration. However, the cellular signaling pathways controlling the proliferation and differentiation of myoblasts are not fully understood. We demonstrate that Janus kinase 1 (JAK1) is required for myoblast proliferation and that it also functions as a checkpoint to prevent myoblasts from premature differentiation. Deliberate knockdown of JAK1 in both primary and immortalized myoblasts induces precocious myogenic differentiation with a concomitant reduction in cell proliferation. This is caused, in part, by an accelerated induction of MyoD, myocyte enhancer–binding factor 2 (MEF2), p21Cip1, and p27Kip1, a faster down-regulation of Id1, and an increase in MEF2-dependent gene transcription. Downstream of JAK1, of all the signal transducer and activator of transcriptions (STATs) present in myoblasts, we find that only STAT1 knockdown promotes myogenic differentiation in both primary and immortalized myoblasts. Leukemia inhibitory factor stimulates myoblast proliferation and represses differentiation via JAK1–STAT1–STAT3. Thus, JAK1–STAT1–STAT3 constitutes a signaling pathway that promotes myoblast proliferation and prevents premature myoblast differentiation.

scholarly journals Loss of IGF-IEa or IGF-IEb Impairs Myogenic Differentiation

Endocrinology ◽  
2011 ◽  
Vol 152 (5) ◽  
pp. 1923-1934 ◽  
Author(s):  
Ronald W. Matheny ◽  
Bradley C. Nindl
Keyword(s):  
Splice Variants ◽  
Myogenic Differentiation ◽  
Horse Serum ◽  
Myoblast Differentiation ◽  
Proliferation And Differentiation ◽  
Igf I ◽  
Simultaneous Loss ◽  
Functional Relevance ◽  
Free Media ◽  
The Impact

Actions of protein products resulting from alternative splicing of the Igf1 gene have received increasing attention in recent years. However, the significance and functional relevance of these observations remain poorly defined. To address functions of IGF-I splice variants, we examined the impact of loss of IGF-IEa and IGF-IEb on the proliferation and differentiation of cultured mouse myoblasts. RNA interference-mediated reductions in total IGF-I, IGF-IEa alone, or IGF-IEb alone had no effect on cell viability in growth medium. However, cells deficient in total IGF-I or IGF-IEa alone proliferated significantly slower than control cells or cells deficient in IGF-IEb in serum-free media. Simultaneous loss of both or specific loss of either splice variant significantly inhibited myosin heavy chain (MyHC) immunoreactivity by 70–80% (P < 0.01) under differentiation conditions (48 h in 2% horse serum) as determined by Western immunoblotting. This loss in protein was associated with reduced MyHC isoform mRNAs, because reductions in total IGF-I or IGF-IEa mRNA significantly reduced MyHC mRNAs by approximately 50–75% (P < 0.05). Loss of IGF-IEb also reduced MyHC isoform mRNA significantly, with the exception of Myh7, but to a lesser degree (∼20–40%, P < 0.05). Provision of mature IGF-I, but not synthetic E peptides, restored Myh3 expression to control levels in cells deficient in IGF-IEa or IGF-IEb. Collectively, these data suggest that IGF-I splice variants may regulate myoblast differentiation through the actions of mature IGF-I and not the E peptides.

scholarly journals Modulation of Muscle Atrophy, Fatigue and MLC Phosphorylation by MuRF1 as Indicated by Hindlimb Suspension Studies on MuRF1-KO Mice

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Siegfried Labeit ◽  
Christine H. Kohl ◽  
Christian C. Witt ◽  
Dittmar Labeit ◽  
Jeong Jung ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Muscle Atrophy ◽  
Soleus Muscle ◽  
Coiled Coil ◽  
Hindlimb Suspension ◽  
Twitch Potentiation ◽  
Muscle Tissues ◽  
Mlc Phosphorylation ◽  
First Time ◽  
Muscle Unloading

MuRF1 is a member of the TRIM/RBCC superfamily, a gene family that encompasses a large variety of proteins, all sharing the conserved TRIM (TripartiteMotive) sequential array ofRING,B-box, and coiled-coil domains. Within this family, MuRF1(also named TRIM63) is a specialized member that contributes to the development of muscle atrophy and sarcopenia. Here we studied MuRF1's role in muscle atrophy during muscle unloading induced by hindlimb suspension. Consistent with previous studies, we found that MuRF1 inactivation leads to an attenuated muscle atrophy response. The amount of protection was higher as compared to the denervation model, and within the 10 day-suspension period the soleus muscle was spared from atrophy in MuRF1-KO mice. Contractility studies on hindlimb suspended muscle tissues suggested that MuRF1's functions extend beyond muscle trophicity and implicate MuRF1 in muscle fatigue and MLC phosphorylation control: soleus muscle from MuRF1-KO mice fatigued significantly faster and in addition showed a reduced posttetanic twitch potentiation. Thus the present work further established the role of MuRF1 in muscle atrophy and for the first time shows that MuRF1 plays a role in muscle fatigue and twitch potentiation.

Abstract 330: Metallothionein Preservation Of Cardiac Akt2 Signaling By Down-regulating Trb3 Prevents Diabetic Cardiomyopathy

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
YI TAN ◽  
Xiaoqing Yan ◽  
Shanshan Zhou ◽  
Yong Li ◽  
Yan Li ◽  
...  
Keyword(s):  
Diabetic Cardiomyopathy ◽  
Insulin Signaling ◽  
Glycogen Synthase ◽  
Critical Role ◽  
Negative Regulator ◽  
H9c2 Cells ◽  
Akt Phosphorylation ◽  
Gsk 3Β

Cardiac insulin resistance is a key pathogenic factor for diabetic cardiomyopathy, but its mechanism remains largely unclear. Here we demonstrated that diabetes significantly inhibited cardiac Akt phosphorylation from 2 weeks to 2 months in wide-type (WT) mice, but not in cardiac-specific metallothionein-transgenic (MT-TG) mice. Cardiac Akt2 expression and phosphorylation was decreased and insulin-induced cardiac Akt2 and GSK-3β phosphorylation and glycogen synthase dephosphorylation were also decreased in WT, but not MT-TG, diabetic mice. Deletion of the Akt2 gene either in vitro H9c2 cells or in vivo significantly impaired cardiac glucose metabolic signaling. In addition, diabetes significantly increased cardiac Akt negative regulator tribbles (TRB)3 expression only in WT mice, suggesting the possible contribution of MT inhibition of diabetic up-regulation of TRB3 to Akt2 function preservation. Cardiac H9c2 cells with and without forced MT-overexpression (MT-H9c2) were treated with tert-butyl hydroperoxide (tBHP), which significantly reduced Akt2 phosphorylation in both basal and insulin-stimulating conditions only in H9c2 cells. Silencing TRB3 expression with SiRNA completely prevented tBHP’s inhibition of insulin-stimulated Akt2 phosphorylation in H9c2 cells, while overexpression of TRB3 in MT-H9c2 cells completely abolished MT preservation of insulin-stimulated Akt2 phosphorylation. Forced-overexpression of TRB3 by adenovirus-mediated gene delivery in MT-TG hearts also abolished MT’s preservation of cardiac insulin signaling and prevention of diabetic cardiomyopathy. These results suggest that diabetes-attenuated cardiac Akt2 function via up-regulating TRB3 plays a critical role in diabetic inhibition of insulin signaling in the heart. MT preserved cardiac Akt2-mediated insulin signaling by inhibiting TRB3, leading to the prevention of diabetic cardiomyopathy.

Effects of the cAMP-elevating agents cilostamide, cilostazol and forskolin on the phosphorylation of Akt and GSK-3β in platelets

2009 ◽  
Vol 102 (08) ◽  
pp. 327-335 ◽  
Author(s):  
Hideki Hayashi ◽  
Toshiki Sudo
Keyword(s):  
Platelet Function ◽  
Kinase Inhibitor ◽  
Glycogen Synthase ◽  
Inhibitory Effect ◽  
Intracellular Camp ◽  
Akt Phosphorylation ◽  
Pi3k Signalling ◽  
Dependent Protein ◽  
Aggregation Inhibition ◽  
Gsk 3Β

SummaryElevating intracellular cAMP has been shown to inhibit platelet function. cAMP interferes with platelet-activating signals which lead to aggregation inhibition, but the precise mechanism is unclear.The present study examined if cAMP-elevating agents inhibited phosphatidylinositol 3-kinase (PI3-kinase) signaling in rat platelets by immunoblotting. Akt is one of the key molecules downstream of PI3K, and is phosphorylated by collagen stimulation. The phosphodiesterase-3 (PDE3) inhibitors cilostamide and cilostazol, and the adenylate cyclase activator forskolin, inhibited collagen-induced Akt phosphorylation at Ser473.The inhibitory effects of these cAMP-elevating agents on Akt phosphorylation were unchanged in the presence of the PKA (cyclic AMP-dependent protein kinase) inhibitor H-89. These effects were consistent with inhibition of platelet aggregation. It is known that inhibition of Akt phosphorylation leads to inhibition of phosphorylation of glycogen synthase kinase 3-beta (GSK-3β), which is an effector of Akt, but cAMP-elevating agents stimulated GSK-3βphosphorylation at Ser9.The PKA inhibitor H-89 attenuated GSK-3βphosphorylation.The cAMP-elevating agents cilostamide, cilostazol and forskolin did not directly affect the enzyme activity of PI3-kinase.These results suggested that cAMP-elevating agents have two effects on PI3K signalling: inhibition of Akt phosphorylation independent of PKA; and stimulation of GSK-3β phosphorylation dependent on PKA. Our results provide new insights into the inhibitory effect of cAMPelevating agents on platelet function.

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