Inhibition of insulin signaling and adipogenesis by rapamycin: effect on phosphorylation of p70 S6 kinase vs eIF4E-BP1

El-Chaâr, Darine; Gagnon, AnneMarie; Sorisky, Alexander

doi:10.1038/sj.ijo.0802554

Cited by 57 publications

(48 citation statements)

References 36 publications

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“…In an early experiment, it was shown that the addition of rapamycin to the differentiation mixture impairs adipogenesis in mouse and human mesenchymal stem cells (18). In fact, rapamycin inhibits the activity and expression of transcription factor peroxisome proliferator-activated receptor γ (PPARγ) (19), which is the master regulator of adipogenesis. The central importance of mTORC1 in the signaling network of adipocyte stem cell differentiation was fueled by the accumulating knowledge that mTORC1 integrates and transduces signals regulating energy balance (20).…”

mentioning

confidence: 99%

In situ characterization of the mTORC1 during adipogenesis of human adult stem cells on chip

Schneider

Platen

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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Mammalian target of rapamycin (mTOR) is a central kinase integrating nutrient, energy, and metabolite signals. The kinase forms two distinct complexes: mTORC1 and mTORC2. mTORC1 plays an essential but undefined regulatory function for regeneration of adipose tissue. Analysis of mTOR in general is hampered by the complexity of regulatory mechanisms, including protein interactions and/or phosphorylation, in an ever-changing cellular microenvironment. Here, we developed a microfluidic large-scale integration chip platform for culturing and differentiating human adiposederived stem cells (hASCs) in 128 separated microchambers under standardized nutrient conditions over 3 wk. The progression of the stem cell differentiation was measured by determining the lipid accumulation rates in hASC cultures. For in situ protein analytics, we developed a multiplex in situ proximity ligation assay (mPLA) that can detect mTOR in its two complexes selectively in single cells and implemented it on the same chip. With this combined technology, it was possible to reveal that the mTORC1 is regulated in its abundance, phosphorylation state, and localization in coordination with lysosomes during adipogenesis. High-content image analysis and parameterization of the in situ PLA signals in over 1 million cells cultured on four individual chips showed that mTORC1 and lysosomes are temporally and spatially coordinated but not in its composition during adipogenesis.microfluidics | stem cell differentiation | adipogenesis | mTORC1 regulation | multiplexed PLA

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mentioning

confidence: 99%

In situ characterization of the mTORC1 during adipogenesis of human adult stem cells on chip

Schneider

Platen

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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“…Acivation of p70S6K1 p70S6 protein kinase is an insulin-sensitive serin/threonin kinase, located downstream to protein kinase B (PKB), although indirectly as PKB substrate. PKB may phosphorylate mTORC1, and then mTORC1 regulated p70S6K activity [6]. mTORC1 phosphorylated p70S6K1 on Thr 389, allowing phosphoinositide-dependent protein kinase 1 (PDK1) bound and phosphorylated S6K1 on Thr229, therefore, it fully activated S6K1.…”

Section: Discussionmentioning

confidence: 99%

“…In preadipocyte, expression of C/EBPβ dan C/EBPδ is upregulated by the activation of prostacyclin receptor which induces the binding of CREB and/or ATF-1 (activation transcription factor 1) to C/EBP promoter [5]. De Groot et al in El-Charr et al [6] reported that CREB was regulated by p70S6K. However, there has been no studies which evaluate the mTORC1  p70S6K1  CREB  CEBPδ pathway extensively.…”

Section: Introductionmentioning

confidence: 99%

The Role of Creb in Adipogenesis through Mammalian Target of Rapamycin of Complex 1 (mTORC1) Pathyway

Triawanti¹,

Indra²,

Tjokroprawiro³

et al. 2014

IJCEA

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Abstract-One of the tissues taking the biggest part in the pathogenesis of obesity is adipose tissue mainly formed by white fat cells. Recently, the processes adipogenesis become a treatment target for obesity. One of the pathway that allegedly participated in the process of adipogenesis is activated via CREB. The upstream pathway is by means of protein of mammalian targets of rapamycin (mTOR). This study was aimed to determine the role of CREB in adipogenesis through the activation of p70S6K1 by mTORC1.This was an experimental study. Subjects were primary cultured preadipocytes taken from visceral fat of white rats (Rattus norvegicus). Cell cultures were classified into 4 groups: (K) Control of adipogenesis: without rapamycin and RNAi CREB, (A): was given rapamycin 10 nM, (B): was given RNAi CREB 100 nM, (C): was given rapamycin 10 nM and RNAi CREB 100 nM. p70S6K1, CREB activation, and expression of C/EBPδ measured on day 2, 4, and 6, and the morphology of adipocytes on day 6. Data were analyzed with Anova test, LSD test, and Pearson correlation test with 95% confidence level.The data showed that rapamycin activated p70S6K1 and caused lower CREB compared with control group during adipogenesis. These results indicated that adipogenesis was blocked, which resulted from the inhibition of p70S6K1 and CREB activation by rapamycin and RNAi CREB. The inhibition was stronger in rapamycin + RNAi CREB group. Statistically, there was significant correlation between p70S6K1 and CREB; and between CREB and C/EBPδ.It was concluded that the role of CREB in adipogenesis was mediated by the activation of p706K1 by mTORC1.Index Terms-Obesity, adipogenesis, mTORC1, p70S6K1, CREB, C/EBPδ.

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“…PPARγ yang merupakan regulator utama adipogenesis Selain itu, meskipun homeostasis energi tubuh secara (17,18). keseluruhan dipelihara oleh berbagai jalur, kebanyakan…”

Section: Pendahuluanunclassified

“…PKB dapat memfosforilasi sering pula disebut signal transduction and transcription mTORC1 dan kemudian mTORC1 meregulasi aktivitas protein meregulasi berbagai aspek pada proses seluler p70S6K (17 korelasi positif antara aktivitas GPDH dan asam lemak seluler terutama MUFA C16:1 dan C18:1 (28). Pada penelitian ini kelompok yang diberi kombinasi rapamycin dan inhibitor STAT3 menunjukkan aktivasi Pada penelitian ini, oleh karena terjadi penghambatan STAT3 yang paling rendah dibandingkan dengan yang pada jalur upstream dari proses adipogenesis yaitu dengan hanya diberi inhibitor STAT3 saja atau rapamycin saja.…”

Section: Aktivitas Enzim Glisero-3-fosfodehidrogenase (Gpdh)unclassified

Regulasi Adipogenesis oleh mTORC1 melalui Jalur ST A T3

Triawanti

Indra

Tjokroprawiro

et al. 2013

JKB

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ABSTRAKObesitas merupakan suatu penyakit kelebihan massa lemak tubuh yang mempunyai efek merugikan bagi kesehatan. Pada saat ini proses adipogenesis menjadi salah satu target terapi obesitas. Salah satu jalur yang diduga teraktivasi pada proses adipogenesis adalah melalui aktivasi STAT3 yang salah satu jalur hulunya melalui protein mammalian target of rapamycin complex 1 (mTOR). Penelitian ini bertujuan untuk membuktikan proses adipogenesis melalui jalur STAT3 yang diaktivasi oleh mTORC1. Penelitian ini merupakan penelitian eksperimental dengan rancangan post test only control. Untuk penghambatan mTORC1 digunakan rapamycin dan penghambatan STAT3 digunakan inhibitor STAT3 peptide. Subjek penelitian adalah kultur primer sel preadiposit yang diambil dari lemak viseral tikus putih Rattus norvegicus. Setelah kultur sel preadiposit dinilai konfluen minimal 70-80% dilakukan induksi diferensiasi dan dibagi menjadi 4 kelompok yakni (K) kontrol (A): diberi rapamycin 10 nM, (B): diberi inhibitor STAT3 100 µM (C): diberi inhibitor STAT3 100 µM dan rapamycin 10 nM. Parameter yang diukur adalah aktivasi p70S6K1, STAT3, ekspresi C/EBPδ, aktivitas enzim Glyserol-3-fosfodehidrogenase (GPDH) pada hari ke-2, ke-4 dan ke-6 serta gambaran morfologis sel adiposit. Analisis statistik menggunakan uji ANOVA, Duncan dan korelasi Pearson dengan tingkat kepercayaan 95%. Hasil penelitian membuktikan terjadi penghambatan proses adipogenesis karena penghambatan aktivasi p70S6K1, dan STAT3 oleh rapamycin dan inhibitor STAT3. Penghambatan akan lebih kuat pada pemberian kombinasi rapamycin dengan inhibitor STAT3. Secara statistik terdapat hubungan antara p70S6K1 dengan STAT3 serta antara STAT3 dengan enzim GPDH. Dapat disimpulkan bahwa proses adipogenesis dapat diregulasi oleh mTORC1 melalui aktivasi p70S6K1 dan STAT3.Kata Kunci: Adiposit, obesitas, mTORC1, p70S6K1, STAT3 ABSTRACT Recently, the processes of adipogenesis become a treatment target for obesity. One of the pathways that allegedly participated in the process of adipogenesis is activated via STAT3. The upstream line of is protein of mammalian targets of rapamycin complex 1 (mTOR). This study aimed to determine the role of STAT3 in adipogenesis through activation of p70S6K1 by mTORC1. This was an experimental study with a post test only with control group design. Subjects were primary cultured preadipocytes taken from visceral fat white rat (Rattus norvegicus). As cell cultured were at least 70-80% confluent, the induction of differentiation of preadipocytes were initiated. Cell cultures were divided into 4 groups: (K) Control of adipogenesis (

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Inhibition of insulin signaling and adipogenesis by rapamycin: effect on phosphorylation of p70 S6 kinase vs eIF4E-BP1

Cited by 57 publications

References 36 publications

In situ characterization of the mTORC1 during adipogenesis of human adult stem cells on chip

In situ characterization of the mTORC1 during adipogenesis of human adult stem cells on chip

The Role of Creb in Adipogenesis through Mammalian Target of Rapamycin of Complex 1 (mTORC1) Pathyway

Regulasi Adipogenesis oleh mTORC1 melalui Jalur ST A T3

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