The Role of Mitochondria in Stem Cell Biology

2007 ◽  
Vol 27 (1-3) ◽  
pp. 165-171 ◽  
Author(s):  
Claudia Nesti ◽  
Livia Pasquali ◽  
Francesca Vaglini ◽  
Gabriele Siciliano ◽  
Luigi Murri

This mini-review summarizes the current literature on the role of mitochondrial DNA mutations and mitochondrial metabolism in stem cell biology. The possible uses of stem cells as a therapeutic tool in mitochondrial disorders are also reported.

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Muhammad Nawaz ◽  
Farah Fatima ◽  
Krishna C. Vallabhaneni ◽  
Patrice Penfornis ◽  
Hadi Valadi ◽  
...  

Stem cells are proposed to continuously secrete trophic factors that potentially serve as mediators of autocrine and paracrine activities, associated with reprogramming of the tumor microenvironment, tissue regeneration, and repair. Hitherto, significant efforts have been made to understand the level of underlying paracrine activities influenced by stem cell secreted trophic factors, as little is known about these interactions. Recent findings, however, elucidate this role by reporting the effects of stem cell derived extracellular vesicles (EVs) that mimic the phenotypes of the cells from which they originate. Exchange of genetic information utilizing persistent bidirectional communication mediated by stem cell-EVs could regulate stemness, self-renewal, and differentiation in stem cells and their subpopulations. This review therefore discusses stem cell-EVs as evolving communication factors in stem cell biology, focusing on how they regulate cell fates by inducing persistent and prolonged genetic reprogramming of resident cells in a paracrine fashion. In addition, we address the role of stem cell-secreted vesicles in shaping the tumor microenvironment and immunomodulation and in their ability to stimulate endogenous repair processes during tissue damage. Collectively, these functions ensure an enormous potential for future therapies.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 95-95 ◽  
Author(s):  
Keisuke Ito ◽  
Paolo Sportoletti ◽  
John G Clohessy ◽  
Grisendi Silvia ◽  
Pier Paolo Pandolfi

Abstract Abstract 95 Myelodysplastic syndrome (MDS) is an incurable stem cell disorder characterized by ineffective hematopoiesis and an increased risk of leukemia transformation. Nucleophosmin (NPM) is directly implicated in primitive hematopoiesis, the pathogenesis of hematopoietic malignancies and more recently of MDS. However, little is known regarding the molecular role and function of NPM in MDS pathogenesis and in stem cell biology. Here we present data demonstrating that NPM plays a critical role in the maintenance of hematopoietic stem cells (HSCs) and the transformation of MDS into leukemia. NPM is located on chromosome 5q and is frequently lost in therapy-related and de novo MDS. We have previously shown that Npm1 acts as a haploinsufficient tumor suppressor in the hematopoietic compartment and Npm1+/− mice develop a hematologic syndrome with features of human MDS, including increased susceptibility to leukemogenesis. As HSCs have been demonstrated to be the target of the primary neoplastic event in MDS, a functional analysis of the HSC compartment is essential to understand the molecular mechanisms in MDS pathogenesis. However, the role of NPM in adult hematopoiesis remains largely unknown as Npm1-deficiency leads to embryonic lethality. To investigate NPM function in adult hematopoiesis, we have generated conditional knockout mice of Npm1, using the Cre-loxP system. Analysis of Npm1 conditional mutants crossed with Mx1-Cre transgenic mice reveals that Npm1 plays a crucial role in adult hematopoiesis and ablation of Npm1 in adult HSCs leads to aberrant cycling and followed by apoptosis. Analysis of cell cycle status revealed that HSCs are impaired in their ability to maintain quiescence after Npm1-deletion and are rapidly depleted in vivo as well as in vitro. Competitive reconstitution assay revealed that Npm1 acts cell-autonomously to maintain HSCs. Conditional inactivation of Npm1 leads to an MDS phenotype including a profoundly impaired ability to differentiate into cells of the erythroid lineage, megakaryocyte dyspoiesis and centrosome amplification. Furthermore, Npm1 loss evokes a p53-dependent response and Npm1-deleted HSCs undergo apoptosis in vivo and in vitro. Strikingly, transfer of the Npm1 mutation into a p53-null background rescued the apoptosis of Npm1-ablated HSCs and resulted in accelerated transformation to an aggressive and lethal form of acute myeloid leukemia. Our findings highlight the crucial role of NPM in stem cell biology and identify a new mechanism by which MDS can progress to leukemia. This has important therapeutic implications for de novo MDS as well as therapy-related MDS, which is known to rapidly evolve to leukemia with frequent loss or mutation of TRP53. Disclosures: No relevant conflicts of interest to declare.


2012 ◽  
Vol 27 ◽  
pp. 167-184 ◽  
Author(s):  
Ceren Aksoy ◽  
Feride Severcan

Recent researches have mainly displayed the significant role of stem cells in tissue renewal and homeostasis with their unique capacity to develop different cell types. These findings have clarified the importance of stem cells to improve the effectiveness of any cell therapy for regenerative medicine. Identification of purity and differentiation stages of stem cells are the greatest challenges of stem cell biology and regenerative medicine. The existing methods to carefully monitor and characterize the stem cells have some unwanted effects on the properties of stem cells, and these methods also do not provide real-time information about cellular conditions. These challenges enforce the usage of nondestructive, rapid, sensitive, high quality, label-free, cheep, and innovative chemical monitoring methods. In this context, vibrational spectroscopy provides promissing alternative to get new information into the field of stem cell biology for chemical analysis, quantification, and imaging of stem cells. Raman and infrared spectroscopy and imaging can be used as a new complimentary spectroscopic approaches to gain new insight into stem cell reseaches for future therapeutic and regenerative medicines. In this paper, recent developments in applications of vibrational spectroscopy techniques for stem cell characterization and identification are presented.


2010 ◽  
Vol 138 (5) ◽  
pp. S-499
Author(s):  
Masahiko Tsujii ◽  
Jumpei Kondo ◽  
Tomofumi Akasaka ◽  
Ying Jin ◽  
Yoshito Hayashi ◽  
...  

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Mina Elahy ◽  
Swati Baindur-Hudson ◽  
Crispin R. Dass

Encoded by a single gene, PEDF is a 50 kDa glycoprotein that is highly conserved and is widely expressed among many tissues. Most secreted PEDF deposits within the extracellular matrix, with cell-type-specific functions. While traditionally PEDF is known as a strong antiangiogenic factor, more recently, as this paper highlights, PEDF has been linked with stem cell biology, and there is now accumulating evidence demonstrating the effects of PEDF in a variety of stem cells, mainly in supporting stem cell survival and maintaining multipotency.


Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1002
Author(s):  
Fabiola Marino ◽  
Mariangela Scalise ◽  
Eleonora Cianflone ◽  
Luca Salerno ◽  
Donato Cappetta ◽  
...  

Over the years strong evidence has been accumulated showing that aerobic physical exercise exerts beneficial effects on the prevention and reduction of cardiovascular risk. Exercise in healthy subjects fosters physiological remodeling of the adult heart. Concurrently, physical training can significantly slow-down or even reverse the maladaptive pathologic cardiac remodeling in cardiac diseases, improving heart function. The underlying cellular and molecular mechanisms of the beneficial effects of physical exercise on the heart are still a subject of intensive study. Aerobic activity increases cardiovascular nitric oxide (NO) released mainly through nitric oxidase synthase 3 activity, promoting endothelium-dependent vasodilation, reducing vascular resistance, and lowering blood pressure. On the reverse, an imbalance between increasing free radical production and decreased NO generation characterizes pathologic remodeling, which has been termed the “nitroso-redox imbalance”. Besides these classical evidence on the role of NO in cardiac physiology and pathology, accumulating data show that NO regulate different aspects of stem cell biology, including survival, proliferation, migration, differentiation, and secretion of pro-regenerative factors. Concurrently, it has been shown that physical exercise generates physiological remodeling while antagonizes pathologic remodeling also by fostering cardiac regeneration, including new cardiomyocyte formation. This review is therefore focused on the possible link between physical exercise, NO, and stem cell biology in the cardiac regenerative/reparative response to physiological or pathological load. Cellular and molecular mechanisms that generate an exercise-induced cardioprotective phenotype are discussed in regards with myocardial repair and regeneration. Aerobic training can benefit cells implicated in cardiovascular homeostasis and response to damage by NO-mediated pathways that protect stem cells in the hostile environment, enhance their activation and differentiation and, in turn, translate to more efficient myocardial tissue regeneration. Moreover, stem cell preconditioning by and/or local potentiation of NO signaling can be envisioned as promising approaches to improve the post-transplantation stem cell survival and the efficacy of cardiac stem cell therapy.


2016 ◽  
Author(s):  
Αθανάσιος Στεργιόπουλος

Το δυναμικό και η ικανότητα αυτο-ανανέωσης και διαφοροποίησης των νευρικών βλαστικών κυττάρων (ΝΒΚ) ελέγχονται από τη δράση διαφόρων μεταγραφικών παραγόντων και πυρηνικών υποδοχέων, επηρεάζοντας μ ’αυτόν τον τρόπο την ανάπτυξη και τη λειτουργία του κεντρικού νευρικού συστήματος (ΚΝΣ). Στην παρούσα μελέτη χαρακτηρίσαμε τον ορφανό πυρηνικό υποδοχέα NR5A2 (LRH1), ως ένα νέο μόριο το οποίο κατέχει κεντρικό αναπτυξιακό ρόλο στο ΚΝΣ. Με πειράματα υπερ-έκφρασης και αποσιώπησης γονιδίων σε πρωτογενή ΝΒΚ καθώς και με ανάλυση εμβρύων ποντικών στα οποία έχει επιτραπεί η ιστο-ειδική και χρονική εξάλειψη του NR5A2, δείξαμε πως ο NR5A2 είναι ικανός να διακόπτει τον πολλαπλασιασμό των ΝΒΚ, οδηγώντας τα προς τη νευρωνική διαφοροποίηση με την παράλληλη απώλεια των αστροκυττάρων. Σε μηχανιστική βάση, ο NR5A2 ελέγχει αυτούς τους φαινοτύπους μέσω της άμεσης επίδρασής του στον γενετικό τόπο του Ink4/Arf, στο Prox1, το οποίο αποτελεί καθοδικό στόχο των προ-νευρικών γονιδίων, καθώς επίσης και στα σηματοδοτικά μονοπάτια του Notch1 και του JAK/STAT. Αντιθέτως, ο NR5A2 ρυθμίζεται ανοδικά από προ-νευρικά γονίδια και από τα Notch1 και JAK/STAT μονοπάτια. Συμπερασματικά, οι παρατηρήσεις μας προτείνουν τον NR5A2 σαν ένα νέο υποδοχέα-ρυθμιστή της ανάπτυξης του ΚΝΣ, και, σε συνδυασμό με την ανακάλυψη αγωνιστών/ανταγωνιστών του, τον καθιστούν υποψήφιο στόχο στην ανάπτυξη θεραπευτικών στρατηγικών αναγεννητικής ιατρικής του ΚΝΣ.


2015 ◽  
Author(s):  
◽  
Jason Neville Sterrenberg

The therapeutic potential of stem cells is already being harnessed in clinical trails. Of even greater therapeutic potential has been the discovery of mechanisms to reprogram differentiated cells into a pluripotent stem cell-like state known as induced pluripotent stem cells (iPSCs). Stem cell nature is governed and maintained by a hierarchy of transcription factors, the apex of which is OCT4. Although much research has elucidated the transcriptional regulation of OCT4, OCT4 regulated gene expression profiles and OCT4 transcriptional activation mechanisms in both stem cell biology and cellular reprogramming to iPSCs, the fundamental biochemistry surrounding the OCT4 transcription factor remains largely unknown. In order to analyze the biochemical relationship between HSP90 and human OCT4 we developed an exogenous active human OCT4 expression model with human OCT4 under transcriptional control of a constitutive promoter. We identified the direct interaction between HSP90 and human OCT4 despite the fact that the proteins predominantly display differential subcellular localizations. We show that HSP90 inhibition resulted in degradation of human OCT4 via the ubiquitin proteasome degradation pathway. As human OCT4 and HSP90 did not interact in the nucleus, we suggest that HSP90 functions in the cytoplasmic stabilization of human OCT4. Our analysis suggests HSP90 inhibition inhibits the transcriptional activity of human OCT4 dimers without affecting monomeric OCT4 activity. Additionally our data suggests that the HSP90 and human OCT4 complex is modulated by phosphorylation events either promoting or abrogating the interaction between HSP90 and human OCT4. Our data suggest that human OCT4 displays the characteristics describing HSP90 client proteins, therefore we identify human OCT4 as a putative HSP90 client protein. The regulation of the transcription factor OCT4 by HSP90 provides fundamental insights into the complex biochemistry of stem cell biology. This may also be suggestive that HSP90 not only regulates stem cell biology by maintaining routine cellular homeostasis but additionally through the direct regulation of pluripotency factors.


2010 ◽  
Vol 134 (12) ◽  
pp. 1740-1749
Author(s):  
Yunyi Kong ◽  
Suresh M. Kumar ◽  
Xiaowei Xu

Abstract Recent advances in molecular genetics and cancer stem cell biology have shed some light on the molecular basis of melanomagenesis. In this review, we will focus on major genetic alterations in the melanoma, particularly pathways involved in cell proliferation, apoptosis, and tumor suppression. The potential role of melanoma-initiating cells during melanomagenesis and progression will also be discussed. Understanding pathogenesis of melanoma may uncover new diagnostic clues and therapeutic targets for this increasingly prevalent disease.


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