The Role of MicroRNAs in the Induction of Pancreatic Differentiation

Author(s):  
Elham Sabouri ◽  
Alireza Rajabzaseh ◽  
Seyedeh Elnaz Enderami ◽  
Ehsan Saburi ◽  
Fatemeh Soleimanifar ◽  
...  

: Stem cell-based therapy is one of the therapeutic options with promising results in the treatment of diabetes. Stem cells from various sources are expanded and induced to generate the cells capable of secreting insulin. These insulinproducing cells [IPCs] could be used as an alternative to islets in the treatment of patients with diabetes. Soluble growth factors, small molecules, gene-encoding transcription factors, and microRNAs [miRNAs] are commonly used for the induction of stem cell differentiation. MiRNAs are small non-coding RNAs with 21-23 nucleotides that are involved in the regulation of gene expression by targeting multiple mRNA targets. Studies have shown the dynamic expression of miRNAs during pancreatic development and stem cell differentiation. MiR-7 and miR-375 are the most abundant miRNAs in pancreatic islet cells and play key roles in pancreatic development and islet cell functions. Some studies have tried to use these small RNAs for the induction of pancreatic differentiation. This review focuses on the miRNAs used in the induction of stem cells into IPCs and discusses their functions in pancreatic β-cells.

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Chintan Kikani ◽  
Michael Xiao ◽  
Xiaoying Wu ◽  
Jared Rutter

Abstract Objectives To determine how nutrient signaling impacts stem cell functions Methods PASK phosphorylation: We measured in situ phosphorylation of PASK by metabolic 32P labeling of stem cells expressing WT or mutant versions of PASK. PASK Activation: PASK activation was measured using in vitro kinase assay using radio-labeled ATP. Myogenesis: Myogenesis was measured by immunohistological, and immunofluorescent analysis of differentiating muscle stem cells. Antibodies used were: Myogenin (F5D-Developmental Hybridoma), MF20 (Myosin heavy chain), Pax7 and MyoD. Results Stem cell fate in the tissue niche is intimately connected with intracellular metabolic state and the extracellular hormonal stimulations. We have identified PAS domain containing Kinase (PASK) as a stem cell enriched protein kinase that is required for establishment of the differentiation program in many stem cell paradigms. For this function, PASK phosphorylates Wdr5, a member of the COMPASS family of histone methyltransferases, to activate the epigenetic processes required for the stem cell differentiation (eLife, 2016). Here we show that a master nutrient sensor, mTOR complex 1 (mTORC1) activates PASK via multi-site phosphorylation during stem cell differentiation. This phosphorylation of PASK by mTORC1 is required for epigenetic activation of the Myogenin transcription, exit from the self-renewal and induction of the myogenesis program. Our data suggest that mTORC1-PASK signaling generates MyoG + committed myoblasts (epigenetically - an early stage of myogenesis), whereas mTORC1-S6K1 signaling is required for myoblast fusion (translationally - later stage of myogenesis). Conclusions Our discoveries show that nutrient signaling can partition stem cell fates during different stages of the myogenesis program downstream of mTOR signaling via activation of two distinct protein kinases. Funding Sources NIH R01 (Chintan Kikani), HHMI (Jared Rutter) Supporting Tables, Images and/or Graphs


2021 ◽  
Vol 22 (8) ◽  
pp. 4011
Author(s):  
Brianna Chen ◽  
Dylan McCuaig-Walton ◽  
Sean Tan ◽  
Andrew P. Montgomery ◽  
Bryan W. Day ◽  
...  

Glioblastoma display vast cellular heterogeneity, with glioblastoma stem cells (GSCs) at the apex. The critical role of GSCs in tumour growth and resistance to therapy highlights the need to delineate mechanisms that control stemness and differentiation potential of GSC. Dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) regulates neural progenitor cell differentiation, but its role in cancer stem cell differentiation is largely unknown. Herein, we demonstrate that DYRK1A kinase is crucial for the differentiation commitment of glioblastoma stem cells. DYRK1A inhibition insulates the self-renewing population of GSCs from potent differentiation-inducing signals. Mechanistically, we show that DYRK1A promotes differentiation and limits stemness acquisition via deactivation of CDK5, an unconventional kinase recently described as an oncogene. DYRK1A-dependent inactivation of CDK5 results in decreased expression of the stemness gene SOX2 and promotes the commitment of GSC to differentiate. Our investigations of the novel DYRK1A-CDK5-SOX2 pathway provide further insights into the mechanisms underlying glioblastoma stem cell maintenance.


2015 ◽  
Vol 35 (10) ◽  
pp. 1700-1711 ◽  
Author(s):  
Fenfang Chen ◽  
Xia Lin ◽  
Pinglong Xu ◽  
Zhengmao Zhang ◽  
Yanzhen Chen ◽  
...  

Bone morphogenetic proteins (BMPs) play vital roles in regulating stem cell maintenance and differentiation. BMPs can induce osteogenesis and inhibit myogenesis of mesenchymal stem cells. Canonical BMP signaling is stringently controlled through reversible phosphorylation and nucleocytoplasmic shuttling of Smad1, Smad5, and Smad8 (Smad1/5/8). However, how the nuclear export of Smad1/5/8 is regulated remains unclear. Here we report that the Ran-binding protein RanBP3L acts as a nuclear export factor for Smad1/5/8. RanBP3L directly recognizes dephosphorylated Smad1/5/8 and mediates their nuclear export in a Ran-dependent manner. Increased expression of RanBP3L blocks BMP-induced osteogenesis of mouse bone marrow-derived mesenchymal stem cells and promotes myogenic induction of C2C12 mouse myoblasts, whereas depletion of RanBP3L expression enhances BMP-dependent stem cell differentiation activity and transcriptional responses. In conclusion, our results demonstrate that RanBP3L, as a nuclear exporter for BMP-specific Smads, plays a critical role in terminating BMP signaling and regulating mesenchymal stem cell differentiation.


2015 ◽  
Vol 3 (16) ◽  
pp. 3150-3168 ◽  
Author(s):  
Sunil Kumar Boda ◽  
Greeshma Thrivikraman ◽  
Bikramjit Basu

Substrate magnetization as a tool for modulating the osteogenesis of human mesenchymal stem cells for bone tissue engineering applications.


2012 ◽  
Vol 287 (44) ◽  
pp. 36777-36791 ◽  
Author(s):  
Hiroaki Fujimori ◽  
Mima Shikanai ◽  
Hirobumi Teraoka ◽  
Mitsuko Masutani ◽  
Ken-ichi Yoshioka

Physiology ◽  
2018 ◽  
Vol 33 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Lucas R. Smith ◽  
Sangkyun Cho ◽  
Dennis E. Discher

Stem cells mechanosense the stiffness of their microenvironment, which impacts differentiation. Although tissue hydration anti-correlates with stiffness, extracellular matrix (ECM) stiffness is clearly transduced into gene expression via adhesion and cytoskeleton proteins that tune fates. Cytoskeletal reorganization of ECM can create heterogeneity and influence fates, with fibrosis being one extreme.


2016 ◽  
Vol 8 (41) ◽  
pp. 7437-7444 ◽  
Author(s):  
Hongjun Song ◽  
Jenna M. Rosano ◽  
Yi Wang ◽  
Charles J. Garson ◽  
Balabhaskar Prabhakarpandian ◽  
...  

A dual-micropore-based microfluidic electrical impedance flow cytometer for non-invasive identification of the differentiation state of mesenchymal stem cells.


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