Abstract 1019: Intracellular Calcium Cycling Mediates Proliferation and Differentiation of Human Cardiac Stem Cells

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Roberto Rizzi ◽  
Michael L Arcarese ◽  
Grazia Esposito ◽  
Claudia Bearzi ◽  
Justin A Korn ◽  
...  

Human cardiac stem cells (hCSCs) are self-renewing, clonogenic and have the ability to differentiate into myocytes, smooth muscle and endothelial cells in vitro and in vivo. Since Ca 2+ plays a crucial role in mechanotransduction and activation of signalling pathways in mature cardiac cells, intracellular Ca 2+ cycling was studied in hCSCs to determine the function of this cation in cell division and commitment to the myocyte lineage. For this purpose, hCSCs were exposed to conditions favouring proliferation and differentiation and affecting intracellular Ca 2+ homeostasis. Moreover, hCSCs were loaded with Fluo-3 and intracellular Ca 2+ levels were monitored by 2-photon microscopy. hCSCs presented spontaneous Ca 2+ spikes mediated by Ca 2+ release from the endoplasmic reticulum (ER). ATP and histamine, which stimulate InsP 3 R-mediated ER Ca 2+ release, increased the occurrence of spikes leading to oscillations in intracellular Ca 2+ . 2-APB, an antagonist of InsP 3 R, inhibited spike formation and oscillatory events. Ryanodine, which acts on the ryanodine receptors, did not alter intracellular Ca 2+ and thapsigargin, a Ca 2+ pump blocker, prevented spontaneous and induced ER Ca 2+ release. Store operated capacitative Ca 2+ entry was evoked by increasing extracellular Ca 2+ after depletion of the ER. Ca 2+ entry was blocked by lanthanum. Additionally, patch-clamp experiments indicated the absence of the voltage-activated L-type Ca 2+ current in hCSCs. Exposure of hCSCs to IGF-1 triggered acutely Ca 2+ spikes and increased chronically their occurrence. Over a period of 24 hours, IGF-1 resulted in more than 100% increase in the proliferation of hCSCs measured by BrdU labelling. Similarly, ATP enhanced proliferation of hCSC by ~60%. Importantly, incubation with 2-APB reduced by ~50% BrdU incorporation and abolished the effect of IGF-1 and ATP on both Ca 2+ spikes and cell proliferation. In the presence of differentiating medium, the frequency of Ca 2+ spikes in active hCSCs increased significantly. Additionally, enhanced Ca 2+ cycling increased the number of hCSCs committed to the myocyte lineage, while attenuations in this phenomenon blunted hCSC differentiation. Thus, InsP 3 R-mediated Ca 2+ spikes play an obligatory role in hCSC growth and differentiation.

2021 ◽  
Vol 22 (4) ◽  
pp. 1824
Author(s):  
Matthias Mietsch ◽  
Rabea Hinkel

With cardiovascular diseases affecting millions of patients, new treatment strategies are urgently needed. The use of stem cell based approaches has been investigated during the last decades and promising effects have been achieved. However, the beneficial effect of stem cells has been found to being partly due to paracrine functions by alterations of their microenvironment and so an interesting field of research, the “stem- less” approaches has emerged over the last years using or altering the microenvironment, for example, via deletion of senescent cells, application of micro RNAs or by modifying the cellular energy metabolism via targeting mitochondria. Using autologous muscle-derived mitochondria for transplantations into the affected tissues has resulted in promising reports of improvements of cardiac functions in vitro and in vivo. However, since the targeted treatment group represents mainly elderly or otherwise sick patients, it is unclear whether and to what extent autologous mitochondria would exert their beneficial effects in these cases. Stem cells might represent better sources for mitochondria and could enhance the effect of mitochondrial transplantations. Therefore in this review we aim to provide an overview on aging effects of stem cells and mitochondria which might be important for mitochondrial transplantation and to give an overview on the current state in this field together with considerations worthwhile for further investigations.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Lihua Yin ◽  
Wenxiao Cheng ◽  
Zishun Qin ◽  
Hongdou Yu ◽  
Zhanhai Yu ◽  
...  

This study is to explore the osteogenesis potential of the human periodontal ligament stem cells (hPDLSCs) induced by naringin in vitro and in vitro. The results confirmed that 1 μM naringin performs the best effect and a collection of bone-related genes (RUNX2,COL1A2, OPN, and OCN) had significantly higher expression levels compared to the control group. Furthermore, a typical trabecular structure was observed in vivo, surrounded by a large amount of osteoblasts. These results demonstrated that naringin, at a concentration of 1 μM, can efficiently promote the proliferation and differentiation of hPDLSCs both in vitro and in vivo.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Andrew J Smith ◽  
Iolanda Aquila ◽  
Beverley J Henning ◽  
Mariangela Scalise ◽  
Bernardo Nadal-Ginard ◽  
...  

The identification of resident, endogenous cardiac stem cells (eCSCs) has re-shaped our understanding of cardiac cellular physiology, while offering a significant potential therapeutic avenue. The biology of these cells must be better understood to harness their potential benefits. We used an acute dose (s.c.; 5mgkg-1) of isoproterenol (ISO) to induce diffuse cardiac injury, with associated eCSC activation, in rats. As peak eCSC activation was at 24 hours post ISO-injury, c-kitpos eCSCs were isolated, characterised and their potential for growth and regenerative potential was assessed in vitro and in vivo, respectively. Activated eCSCs showed increased cell cycling activity (51+1% in S- or G2/M phases vs. 9+2% of quiescent), Ki67 expression (56+7% vs. 10+1%) and TERT expression (14-fold increase vs. quiescent). When directly harvested in culture, activated eCSCs showed augmented proliferation, clonogenicity and cardiosphere formation compared to quiescent eCSCs. Activated eCSCs showed increases in expression of numerous growth factors, particularly HGF, IGF-1, TGF-β, periostin, PDGF-AA and VEGF-A. Furthermore, significant alterations were found in the miRnome, notably increased miR-146b and -221, and decreased miR-192 and -351. ISO+5FU was administrated to mice to induce a model of chronic dilated cardiomyopathy, which is characterized by the ablation of eCSCs and the absence of cardiomyocyte replenishment. In these mice with chronic heart failure, freshly isolated quiescent eCSCs or activated eCSCs (2d post-ISO) were injected through the tail vein. 28 days after injection, activated but not quiescent eCSCs re-populated the resident CSC pool, promoted robust new cardiomyocyte formation and improved cardiac function when compared to saline-treated mice. Dual-labelling with BrdU and EdU at selected stages after ISO injury determined that activated eCSCs returned to a quiescent level by 10 weeks post-injury. In conclusion, CSCs rapidly switch from a quiescent to an activated state to match the myocardial needs for myocyte replacement after injury and then spontaneously go back to quiescence. Harnessing the molecules regulating this process may open up future novel approaches for effective myocardial regeneration.


1977 ◽  
Vol 145 (6) ◽  
pp. 1612-1616 ◽  
Author(s):  
T M Dexter ◽  
M A Moore ◽  
A P Sheridan

A culture system is described in which bone marrow-derived adherent cells can support prolonged proliferation and differentiation of genetically incompatible stem cells and precursor cells. The results suggest that the reactive cells responsible in vivo for host transplantation resistance and for graft-versus-host disease are selectively lost or inhibited in such cultures, which may provide a vehicle for studying some of the cellular mechanisms involved in transplantation resistance.


2019 ◽  
Vol 20 (17) ◽  
pp. 4083
Author(s):  
Xing Yu Li ◽  
Shang Ying Wu ◽  
Po Sing Leung

Pancreatic progenitor cells (PPCs) are the primary source for all pancreatic cells, including beta-cells, and thus the proliferation and differentiation of PPCs into islet-like cell clusters (ICCs) opens an avenue to providing transplantable islets for diabetic patients. Meanwhile, mesenchymal stem cells (MSCs) can enhance the development and function of different cell types of interest, but their role on PPCs remains unknown. We aimed to explore the mechanism-of-action whereby MSCs induce the in vitro and in vivo PPC/ICC development by means of our established co-culture system of human PPCs with human fetal bone marrow-derived MSCs. We examined the effect of MSC-conditioned medium on PPC proliferation and survival. Meanwhile, we studied the effect of MSC co-culture enhanced PPC/ICC function in vitro and in vivo co-/transplantation. Furthermore, we identified IGF1 as a critical factor responsible for the MSC effects on PPC differentiation and proliferation via IGF1-PI3K/Akt and IGF1-MEK/ERK1/2, respectively. In conclusion, our data indicate that MSCs stimulated the differentiation and proliferation of human PPCs via IGF1 signaling, and more importantly, promoted the in vivo engraftment function of ICCs. Taken together, our protocol may provide a mechanism-driven basis for the proliferation and differentiation of PPCs into clinically transplantable islets.


1973 ◽  
Vol 62 (6) ◽  
pp. 756-772 ◽  
Author(s):  
Antonio Scarpa ◽  
Pierpaolo Graziotti

Initial velocities of energy-dependent Ca++ uptake were measured by stopped-flow and dual-wavelength techniques in mitochondria isolated from hearts of rats, guinea pigs, squirrels, pigeons, and frogs. The rate of Ca++ uptake by rat heart mitochondria was 0.05 nmol/mg/s at 5 µM Ca++ and increased sigmoidally to 8 nmol/mg/s at 200 µM Ca++. A Hill plot of the data yields a straight line with slope n of 2, indicating a cooperativity for Ca++ transport in cardiac mitochondria. Comparable rates of Ca++ uptake and sigmoidal plots were obtained with mitochondria from other mammalian hearts. On the other hand, the rates of Ca++ uptake by frog heart mitochondria were higher at any Ca++ concentrations. The half-maximal rate of Ca++ transport was observed at 30, 60, 72, 87, 92 µM Ca++ for cardiac mitochondria from frog, squirrel, pigeon, guinea pig, and rat, respectively. The sigmoidicity and the high apparent Km render mitochondrial Ca++ uptake slow below 10 µM. At these concentrations the rate of Ca++ uptake by cardiac mitochondria in vitro and the amount of mitochondria present in the heart are not consistent with the amount of Ca++ to be sequestered in vivo during heart relaxation. Therefore, it appears that, at least in mammalian hearts, the energy-linked transport of Ca++ by mitochondria is inadequate for regulating the beat-to-beat Ca++ cycle. The results obtained and the proposed cooperativity for mitochondrial Ca++ uptake are discussed in terms of physiological regulation of intracellular Ca++ homeostasis in cardiac cells.


2019 ◽  
Vol 29 (5) ◽  
pp. 727-735 ◽  
Author(s):  
Yuhang Cao ◽  
Yingliang Zhuang ◽  
Junchen Chen ◽  
Weize Xu ◽  
Yikai Shou ◽  
...  

Abstract N 6-methyladenosine (m6A) modification of RNA is deposited by the methyltransferase complex consisting of Mettl3 and Mettl14 and erased by demethylase Fto and Alkbh5 and is involved in diverse biological processes. However, it remains largely unknown the specific function and mechanism of Fto in regulating adult neural stem cells (aNSCs). In the present study, utilizing a conditional knockout (cKO) mouse model, we show that the specific ablation of Fto in aNSCs transiently increases the proliferation of aNSCs and promotes neuronal differentiation both in vitro and in vivo, but in a long term, the specific ablation of Fto inhibits adult neurogenesis and neuronal development. Mechanistically, Fto deficiency results in a significant increase in m6A modification in Pdgfra and Socs5. The increased expression of Pdgfra and decreased expression of Socs5 synergistically promote the phosphorylation of Stat3. The modulation of Pdgfra and Socs5 can rescue the neurogenic deficits induced by Fto depletion. Our results together reveal an important function of Fto in regulating aNSCs through modulating Pdgfra/Socs5-Stat3 pathway.


2018 ◽  
Vol 46 (5) ◽  
pp. 2114-2126 ◽  
Author(s):  
Meng Wu ◽  
Jiaqiang Xiong ◽  
Lingwei Ma ◽  
Zhiyong Lu ◽  
Xian Qin ◽  
...  

Background/Aims: The isolation and establishment of female germline stem cells (FGSCs) is controversial because of questions regarding the reliability and stability of the isolation method using antibody targeting mouse vasa homologue (MVH), and the molecular mechanism of FGSCs self-renewal remains unclear. Thus, there needs to be a simple and reliable method for sorting FGSCs to study them. Methods: We applied the differential adhesion method to enrich FGSCs (DA-FGSCs) from mouse ovaries. Through four rounds of purification and 7-9 subsequent passages, DA-FGSC lines were established. In addition, we assessed the role of the phosphoinositide-3 kinase (PI3K)-AKT pathway in regulating FGSC self-renewal. Results: The obtained DA-FGSCs spontaneously differentiated into oocyte-like cells in vitro and formed functional eggs in vivo that were fertilized and produced healthy offspring. AKT was rapidly phosphorylated when the proliferation rate of FGSCs increased after 10 passages, and the addition of a chemical PI3K inhibitor prevented FGSCs self-renewal. Furthermore, over-expression of AKT-induced proliferation and differentiation of FGSCs, c-Myc, Oct-4 and Gdf-9 levels were increased. Conclusions: The differential adhesion method provides a more feasible approach and is an easier procedure to establish FGSC lines than traditional methods. The AKT pathway plays an important role in regulation of the proliferation and maintenance of FGSCs. These findings could help promote stem cell studies and provide a better understanding of causes of ovarian infertility, thereby providing potential treatments for infertility.


2020 ◽  
Vol 7 (3) ◽  
pp. 92
Author(s):  
Mariana A. Branco ◽  
Joaquim M.S. Cabral ◽  
Maria Margarida Diogo

The knowledge acquired throughout the years concerning the in vivo regulation of cardiac development has promoted the establishment of directed differentiation protocols to obtain cardiomyocytes (CMs) and other cardiac cells from human pluripotent stem cells (hPSCs), which play a crucial role in the function and homeostasis of the heart. Among other developments in the field, the transition from homogeneous cultures of CMs to more complex multicellular cardiac microtissues (MTs) has increased the potential of these models for studying cardiac disorders in vitro and for clinically relevant applications such as drug screening and cardiotoxicity tests. This review addresses the state of the art of the generation of different cardiac cells from hPSCs and the impact of transitioning CM differentiation from 2D culture to a 3D environment. Additionally, current methods that may be employed to generate 3D cardiac MTs are reviewed and, finally, the adoption of these models for in vitro applications and their adaptation to medium- to high-throughput screening settings are also highlighted.


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