Research and Findings

2010 ◽  
Vol 14 (02) ◽  
pp. 36-39

Singapore Scientists Discover New Concoction to Reprogram Differentiated Cells into Pluripotent Stem Cells. NTU Researchers Complete the World's First in-depth Study of the Malaria Parasite Genome. Cause of Islet Cell Rejection Discovered. Scientist Develops Anti-Cancer Derivative of Vitamin E. Destructive Clover Root Weevils Found.

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1078
Author(s):  
Tae Won Ha ◽  
Ji Hun Jeong ◽  
HyeonSeok Shin ◽  
Hyun Kyu Kim ◽  
Jeong Suk Im ◽  
...  

Human pluripotent stem cells (hPSCs), such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), have a well-orchestrated program for differentiation and self-renewal. However, the structural features of unique proteostatic-maintaining mechanisms in hPSCs and their features, distinct from those of differentiated cells, in response to cellular stress remain unclear. We evaluated and compared the morphological features and stress response of hPSCs and fibroblasts. Compared to fibroblasts, electron microscopy showed simpler/fewer structures with fewer networks in the endoplasmic reticulum (ER) of hPSCs, as well as lower expression of ER-related genes according to meta-analysis. As hPSCs contain low levels of binding immunoglobulin protein (BiP), an ER chaperone, thapsigargin treatment sharply increased the gene expression of the unfolded protein response. Thus, hPSCs with decreased chaperone function reacted sensitively to ER stress and entered apoptosis faster than fibroblasts. Such ER stress-induced apoptotic processes were abolished by tauroursodeoxycholic acid, an ER-stress reliever. Hence, our results revealed that as PSCs have an underdeveloped structure and express fewer BiP chaperone proteins than somatic cells, they are more susceptible to ER stress-induced apoptosis in response to stress.


2015 ◽  
Vol 27 (1) ◽  
pp. 260
Author(s):  
D. A. Anzalone ◽  
D. Iuso ◽  
P. Toschi ◽  
F. Zacchini ◽  
G. E. Ptak ◽  
...  

Pluripotency is the ability of one cell to generate every cell type of the 3 germ layers, a property typically owned by embryonic stem cells (ESC) and induced pluripotent stem cells (iPSC), with some exceptions; multilineage-differentiating stress-enduring (Muse) cells are an example. Muse cells, described as pre-existing pluripotent stem cells in mesenchymal tissues (Kuroda et al. 2010) are able to form clusters from single cells in suspension culture, express pluripotency factors and differentiate into cell types of the 3 germ layers, like ESC and iPSC. In addition, Muse cells are proposed to be the only source of cells capable to generate iPSC by current methodologies (Wakao et al. 2011). However, it is unclear whether they are normally present in adult tissue, derive from precursors stem or differentiated cells, or are induced by the in vitro conditions. In our work, we tested the hypothesis that the transition from a committed (tissue) to an uncommitted (in vitro culture) environment triggers in the cells the activation of a default gene circuitry leading to pluripotency. Adult skin fibroblasts were obtained from sheep ear biopsy (n = 3) and expanded in vitro (A) or cultured in suspension in hanging drops (B) or in nonadherent dishes (C) in MEM with 10% FBS. In a subsequent experiment, clonal expansion was attempted by culturing single suspension cells in drops of medium (D). Pluripotency was assessed analysing Oct4 and Nanog expression, using real-time PCR (mRNA) and Western blotting (protein), in cultured fibroblasts compared to whole ear biopsy (30-day-old fetus was used as positive control, CTR). Furthermore, in adherent cells (A) and in clusters obtained from suspension culture (B, C, D), Oct4 and Nanog expression was compared by immunofluorescence. We found that while in the ear biopsy not one of these pluripotency markers was expressed, in in vitro-expanded fibroblasts both mRNA and protein expression was detected; mRNA expression value (mean ± s.e.m. relative to CTR) was 0.59 ± 0.18 for Nanog and 0.2 ± 0.07 for Oct4. Moreover, fibroblasts in suspension (B, C, D) were able to form clusters [obtained from 32% (16/50) of single cells, D] similar to those normally obtained with ESC, iPSC. and Muse cells. All the clusters (B, C, D) showed a more intensive signal of Oct4 and Nanog protein compared to adherent cells by immunofluorescence. In the present work we demonstrate that adult somatic cells (skin fibroblasts) express key pluripotency factors, such as OCT4 and Nanog, in both adherent and suspension culture, after removal from the tissue (ear). We can conclude that the simple in vitro culture switches on the expression of pluripotency markers in adult somatic cells. Removal from the context of the tissue probably leads the cells to lose their tissue-specific identity and acquire a new undifferentiated one, which in an optimal condition culture could result in pluripotency. Our interpretation is that reprogramming must be an automatic, default response when differentiated cells are removed from the constraints imposed by a multicellular environment.


eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Ricardo Antonio Rosselló ◽  
Chun-Chun Chen ◽  
Rui Dai ◽  
Jason T Howard ◽  
Ute Hochgeschwender ◽  
...  

Cells are fundamental units of life, but little is known about evolution of cell states. Induced pluripotent stem cells (iPSCs) are once differentiated cells that have been re-programmed to an embryonic stem cell-like state, providing a powerful platform for biology and medicine. However, they have been limited to a few mammalian species. Here we found that a set of four mammalian transcription factor genes used to generate iPSCs in mouse and humans can induce a partially reprogrammed pluripotent stem cell (PRPSCs) state in vertebrate and invertebrate model organisms, in mammals, birds, fish, and fly, which span 550 million years from a common ancestor. These findings are one of the first to show cross-lineage stem cell-like induction, and to generate pluripotent-like cells for several of these species with in vivo chimeras. We suggest that the stem-cell state may be highly conserved across a wide phylogenetic range.


2017 ◽  
Vol 21 (1) ◽  
pp. 144-148 ◽  
Author(s):  
Prajna Guha ◽  
John W. Morgan ◽  
Gustavo Mostoslavsky ◽  
Neil P. Rodrigues ◽  
Ashleigh S. Boyd

2016 ◽  
Vol 11 (3) ◽  
pp. 695-702 ◽  
Author(s):  
WIKTORIA MARIA SUCHORSKA ◽  
EWELINA AUGUSTYNIAK ◽  
MAGDALENA ŁUKJANOW

Author(s):  
Eszter Posfai ◽  
John Paul Schell ◽  
Adrian Janiszewski ◽  
Isidora Rovic ◽  
Alexander Murray ◽  
...  

AbstractTotipotency is the ability of a single cell to give rise to all the differentiated cells that build the conceptus, yet how to capture this property in vitro remains incompletely understood. Defining totipotency relies upon a variety of assays of variable stringency. Here we describe criteria to define totipotency. We illustrate how distinct criteria of increasing stringency can be used to judge totipotency by evaluating candidate totipotent cell types in the mouse, including early blastomeres and expanded or extended pluripotent stem cells. Our data challenge the notion that expanded or extended pluripotent states harbor increased totipotent potential relative to conventional embryonic stem cells under in vivo conditions.


2018 ◽  
Vol 92 (4) ◽  
pp. 1507-1524 ◽  
Author(s):  
Harshal Nemade ◽  
Umesh Chaudhari ◽  
Aviseka Acharya ◽  
Jürgen Hescheler ◽  
Jan Georg Hengstler ◽  
...  

2017 ◽  
Author(s):  
◽  
M. M. Mata-Miranda

Two of the greatest challenges in Stem Cells (SCs) biology and regenerative medicine, are differentiation control of SCs and ensuring the purity of differentiated cells. In this sense, fast, efficient and accurate techniques for SCs characterization and their differentiation into different cell lineages are needed. The aim of this study was to analyse Pluripotent Stem Cells (PSCs) and Differentiated Pancreatic Cells (DPCs) by Fourier Transform Infrared (FTIR) spectroscopy and Principal Component Analysis (PCA). For this purpose, we differentiated PSCs toward DPCs, characterizing the differentiation process at different stages (0, 11, 17 and 21 days) through light microscopy and vibrational spectroscopy. FTIR spectra were analysed with the multivariate method of PCA, using the second derivatives in the protein, carbohydrate and ribose regions. The results indicate that the PCA allows to characterize and discriminate PSCs and DPCs at different stages of differentiation in the analysed spectral regions. From these results, we concluded that the PCA allows the chemically and structural characterization of PSCs and the different stages of their differentiation in a fast, accurate and non-invasive way.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Tackla S. Winston ◽  
Kantaphon Suddhapas ◽  
Chenyan Wang ◽  
Rafael Ramos ◽  
Pranav Soman ◽  
...  

Combination of stem cell technology and 3D biofabrication approaches provides physiological similarity to in vivo tissues and the capability of repairing and regenerating damaged human tissues. Mesenchymal stem cells (MSCs) have been widely used for regenerative medicine applications because of their immunosuppressive properties and multipotent potentials. To obtain large amount of high-quality MSCs without patient donation and invasive procedures, we differentiated MSCs from human-induced pluripotent stem cells (hiPSC-MSCs) using serum-free E6 media supplemented with only one growth factor (bFGF) and two small molecules (SB431542 and CHIR99021). The differentiated cells showed a high expression of common MSC-specific surface markers (CD90, CD73, CD105, CD106, CD146, and CD166) and a high potency for osteogenic and chondrogenic differentiation. With these cells, we have been able to manufacture MSC tissue rings with high consistency and robustness in pluronic-coated reusable PDMS devices. The MSC tissue rings were characterized based on inner diameter and outer ring diameter and observed cell-type-dependent tissue contraction induced by cell-matrix interaction. Our approach of simplified hiPSC-MSC differentiation, modular fabrication procedure, and serum-free culture conditions has a great potential for scalable manufacturing of MSC tissue rings for different regenerative medicine applications.


Sign in / Sign up

Export Citation Format

Share Document