Differential activation of Ca2+ influx channels modulate stem cell potency, their proliferation/viability and tissue regeneration

AbstractStem cells have indefinite self-renewable capability; however, factors that modulate their pluripotency/function are not fully identified. Here we show that store-dependent Ca2+ entry is essential for modulating the function of bone marrow-derived mesenchymal stem cells (MSCs). Increasing external Ca2+ modulated cell cycle progression that was critical for MSCs survival. Additionally, Ca2+ was critical for stem proliferation, its differentiation, and maintaining stem cell potential. Ca2+ channel characterization, including gene silencing, showed two distinct Ca2+ entry channels (through Orai1/TRPC1 or via Orai3) that differentially regulate the proliferation and viability of MSCs. Importantly, NFκB translocation, but not JNK/ERK into the nucleus, was observed upon store depletion, which was blocked by the addition of Ca2+ channel inhibitors. Radiation lead to a decrease in saliva secretion, decrease in acinar cell number, and enlarged ducts were observed, which were restored by the transplantation of stem cells that were propagated in higher Ca2+. Finally radiation showed a decrese in TRPC1 expression along with a decrese in AQP5, which was again restored upon MSC tranplantation. Together these results suggest that Ca2+ entry is essential for stem cell function that could be critical for regenerative medicine.

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Cell size is a determinant of stem cell potential during aging

10.1101/2020.10.27.355388 ◽

2020 ◽

Author(s):

Jette Lengefeld ◽

Chia-Wei Cheng ◽

Pema Maretich ◽

Marguerite Blair ◽

Hannah Hagen ◽

...

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Cell Size ◽

Cell Function ◽

Cell Aging ◽

Proliferative Potential ◽

Cell Potential ◽

Hematopoietic Stem ◽

Stem Cell Potential

AbstractStem cells are remarkably small in size. Whether small size is important for stem cell function is unknown. We find that murine hematopoietic stem cells (HSCs) enlarge under conditions known to decrease stem cell function. This decreased fitness of large HSCs is due to reduced proliferative potential. Preventing HSC enlargement by inhibiting macromolecule biosynthesis or reducing large HSCs size by shortening G1 averts the loss of stem cell potential under conditions causing stem cell exhaustion. Finally, we show that a fraction of murine and human HSCs enlarge during aging. Preventing this age-dependent enlargement improves HSC function. We conclude that small cell size is important for stem cell function in vivo and propose that stem cell enlargement contributes to their functional decline during aging.One Sentence SummarySize increase drives stem cell aging.

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Cell cycle exit and stem cell differentiation are coupled through regulation of mitochondrial activity in the Drosophila testis

10.1101/2021.01.12.426342 ◽

2021 ◽

Author(s):

Diego Sainz de la Maza ◽

Silvana Hof-Michel ◽

Lee Phillimore ◽

Christian Bökel ◽

Marc Amoyel

Keyword(s):

Cell Cycle ◽

Stem Cells ◽

Stem Cell ◽

Cell Cycle Progression ◽

Stem Cell Differentiation ◽

Mitochondrial Activity ◽

Self Renewal ◽

Cycle Progression ◽

Cell Identity ◽

Drosophila Testis

AbstractStem cells maintain tissue homeostasis by proliferating to replace cells lost to damage or natural turnover. Whereas stem and progenitor cells proliferate, fully differentiated cells exit the cell cycle. How cell identity and cell cycle state are coordinated during this process is still poorly understood. The Drosophila testis niche supports germline stem cells and somatic cyst stem cells (CySCs), which are the only proliferating somatic cells in the testis. CySCs give rise to post-mitotic cyst cells and therefore provide a tractable model to ask how stem cell identity is linked to proliferation. We show that the G1/S cyclin, Cyclin E, is required for CySC self-renewal; however, its canonical transcriptional regulator, a complex of the E2f1 and Dp transcription factors is dispensable for self-renewal and cell cycle progression. Nevertheless, we demonstrate that E2f1/Dp activity must be silenced to allow CySCs to differentiate. We show that E2f1/Dp activity inhibits the expression of genes important for mitochondrial activity. Furthermore, promoting mitochondrial activity or biogenesis is sufficient to rescue the differentiation of CySCs with ectopic E2f1/Dp activity but not their exit from the cell cycle. Our findings together indicate that E2f1/Dp coordinates cell cycle progression with stem cell identity by regulating the metabolic state of CySCs.

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Cell-Intrinsic Heterogeneity Plays An Important Role in the Development of Clonal Dominance after Retroviral Gene Transfer into Hematopoietic Stem Cells

Blood ◽

10.1182/blood.v112.11.819.819 ◽

2008 ◽

Vol 112 (11) ◽

pp. 819-819

Author(s):

Olga S. Kustikova ◽

Bernhard Schiedlmeier ◽

Martijn H. Brugman ◽

Maike Stahlhut ◽

Zhixiong Li ◽

...

Keyword(s):

Stem Cells ◽

Gene Therapy ◽

Stem Cell ◽

Hematopoietic Stem Cells ◽

Insertional Mutagenesis ◽

Cell Potential ◽

Hematopoietic Stem ◽

Long Term Follow Up ◽

Stem Cell Potential

Abstract The development of clonal imbalance after transplantation of genetically modified hematopoietic cells is a cause of concern in the long-term follow-up of patients undergoing gene therapy for the treatment of severe or acquired hematopoietic disorders. We and others have previously described how insertional proto-oncogene dysregulation by transgene integration may provoke clonal restriction and leukemia, thus becoming a dose-limiting toxicity of gene therapy. When targeting populations enriched for or depleted from hematopoietic stem cells (HSC) in the C57Bl6 CD45 chimerism model, we found that intrinsic stem cell potential is a conditio sine qua non for the establishment of expanding insertional mutants. Mice observed for 6–7 months after co-transplantation of gene-modified cells and non-transduced fresh competitor cells were monitored in regular intervals of 6 weeks and the emergence of dominant clones was assessed by flow cytometry in combination with an LM-PCR procedure validated on mixtures of polyclonal and oligoclonal DNA. Dominant clones originating after gammaretroviral insertion in the Evi1 locus reproducibly occurred with a frequency of 1:10,000 when targeting multipotent LSK cells or short-term repopulating HSC (LSK CD34+ CD135−), but no such events were detected in the progeny of >1 million Sca1- Lin- c-Kit+ (LK) cells or ~75,000 multipotent progenitor cells (MPP, LSK CD34+ CD135+). Dominant clones originating from multipotent cells and displaying insertional upregulation of Evi1 showed greatly diminished T lymphopoiesis in vivo, formally demonstrating transforming events. Residual progeny of MPP or LK cells was detected in transplanted animals with insertional events in proto-oncogenes, but these clones were unable to expand to significant levels of hematopoiesis (>1%). Targeting HSC-enriched cell populations (LSK CD34+ CD135− or LSK CD34− CD135−), a comparison of gamma-retroviral transduction conditions in a 5 days serum-free culture period and lentiviral transduction in a 20h protocol revealed that the latter conditions significantly improved chimerism with a greatly increased clonal diversity in the first 8 weeks of repopulation. However, after lentiviral transduction clonal dominance progressively developed over an observation time of 6 months, although there was no evidence for insertional proto-oncogene upregulation as the underlying cause even when using a lentiviral vector with a strong internal enhancer-promoter capable of insertional long-distance effects. Our study suggests two important conclusions: (1) Insertional mutagenesis in gene therapy is unlikely to endow differentiating progenitor cells with (leukemogenic) stem cell potential and (2) clonal restriction developing in the long-term follow-up after transplantation of gene-modified hematopoietic stem cells is not necessarily a side effect of insertional mutagenesis, but may also reflect classical “gene marking” of a stem cell clone with a strong intrinsic potential for competitive dominance.

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The Stem Cell Potential and Multipotency of Human Adipose Tissue-Derived Stem Cells Vary by Cell Donor and Are Different from Those of Other Types of Stem Cells

Cells Tissues Organs ◽

10.1159/000369969 ◽

2014 ◽

Vol 199 (5-6) ◽

pp. 373-383 ◽

Cited By ~ 28

Author(s):

Hyun Jin Yang ◽

Ki-Joo Kim ◽

Min Kyoung Kim ◽

Su Jin Lee ◽

Yeon Hee Ryu ◽

...

Keyword(s):

Stem Cells ◽

Adipose Tissue ◽

Stem Cell ◽

Human Adipose Tissue ◽

Cell Potential ◽

Cell Donor ◽

Stem Cell Potential

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Bub1 is required for maintaining cancer stem cells in breast cancer cell lines

Scientific Reports ◽

10.1038/srep15993 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 22

Author(s):

Jeong Yoon Han ◽

Yu Kyeong Han ◽

Ga-Young Park ◽

Sung Dae Kim ◽

Chang Geun Lee

Keyword(s):

Breast Cancer ◽

Stem Cells ◽

Stem Cell ◽

Cancer Stem Cells ◽

Cancer Stem Cell ◽

Cancer Cell ◽

Breast Cancer Cell ◽

Mitotic Checkpoint ◽

Cell Potential ◽

Stem Cell Potential

Abstract Breast cancer is a leading cause of death among women worldwide due to therapeutic resistance and cancer recurrence. Cancer stem cells are believed to be responsible for resistance and recurrence. Many efforts to overcome resistance and recurrence by regulating cancer stem cells are ongoing. Bub1 (Budding uninhibited by benzimidazoles 1) is a mitotic checkpoint serine/threonine kinase that plays an important role in chromosome segregation. Bub1 expression is correlated with a poor clinical prognosis in patients with breast cancer. We identified that depleting Bub1 using shRNAs reduces cancer stem cell potential of the MDA-MB-231 breast cancer cell line, resulting in inhibited formation of xenografts in immunocompromised mice. These results suggest that Bub1 may be associated with cancer stem cell potential and could be a target for developing anti-breast cancer stem cell therapies.

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PLZF mutation alters mouse hematopoietic stem cell function and cell cycle progression

Blood ◽

10.1182/blood-2015-09-666974 ◽

2016 ◽

Vol 127 (15) ◽

pp. 1881-1885 ◽

Cited By ~ 17

Author(s):

Christelle Vincent-Fabert ◽

Nadine Platet ◽

Amelle Vandevelde ◽

Mathilde Poplineau ◽

Myriam Koubi ◽

...

Keyword(s):

Cell Cycle ◽

Stem Cell ◽

Hematopoietic Stem Cell ◽

Cell Cycle Progression ◽

Cell Function ◽

Cycle Progression ◽

Hematopoietic Stem ◽

Key Points ◽

Mouse Hematopoietic Stem Cell

Key Points Inactivation of PLZF promotes phenotype of HSC aging. PLZF controls HSC cell cycle.

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Establishing cell-intrinsic limitations in cell cycle progression controls graft growth and promotes differentiation of pancreatic endocrine cells

10.1101/2020.03.13.990812 ◽

2020 ◽

Author(s):

Lina Sui ◽

Yurong Xin ◽

Daniela Georgieva ◽

Giacomo Diedenhofen ◽

Leena Haataja ◽

...

Keyword(s):

Cell Cycle ◽

Stem Cells ◽

Stem Cell ◽

Endocrine Cells ◽

Cell Cycle Progression ◽

S Phase ◽

Growth Potential ◽

Proliferative Potential ◽

G1 Arrest ◽

Cycle Progression

AbstractLimitations in cell proliferation are a key barrier to reprogramming differentiated cells to pluripotent stem cells, and conversely, acquiring these limitations may be important to establish the differentiated state. The pancreas, and beta cells in particular have a low proliferative potential, which limits regeneration, but how these limitations are established is largely unknown. Understanding proliferation potential is important for the safty of cell replacement therapy with cell products made from pluripotent stem cell which have unlimited proliferative potential. Here we test a novel hypothesis, that these limitations are established through limitations in S-phase progression. We used a stem cell-based system to expose differentiating stem cells to small molecules that interfere with cell cycle progression either by inducing G1 arrest, impairing S-phase entry, or S-phase completion. Upon release from these molecules, we determined growth potential, differentiation and function of insulin-producing endocrine cells both in vitro and after grafting in vivo. We found that the combination of G1 arrest with a compromised ability to complete DNA replication promoted the differentiation of pancreatic progenitor cells towards insulin-producing cells, improved the stability of the differentiated state, and protected mice from diabetes without the formation of cystic growths. Therefore, a compromised ability to enter S-phase and replicate the genome is a functionally important property of pancreatic endocrine differentiation, and can be exploited to generate insulin-producing organoids with predictable growth potential after transplantation.

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G1-phase progression in pluripotent stem cells

Cellular and Molecular Life Sciences ◽

10.1007/s00018-021-03797-8 ◽

2021 ◽

Author(s):

Menno ter Huurne ◽

Hendrik G. Stunnenberg

Keyword(s):

Cell Cycle ◽

Stem Cells ◽

Cell Cycle Progression ◽

Embryonic Stem ◽

Cell Number ◽

Molecular Networks ◽

Cell Cycle Regulators ◽

Cycle Progression ◽

Expression Of Genes ◽

Promote Cell Cycle Progression

AbstractDuring early embryonic development both the rapid increase in cell number and the expression of genes that control developmental decisions are tightly regulated. Accumulating evidence has indicated that these two seemingly independent processes are mechanistically intertwined. The picture that emerges from studies on the cell cycle of embryonic stem cells is one in which proteins that promote cell cycle progression prevent differentiation and vice versa. Here, we review which transcription factors and signalling pathways play a role in both maintenance of pluripotency as well as cell cycle progression. We will not only describe the mechanism behind their function but also discuss the role of these regulators in different states of mouse pluripotency. Finally, we elaborate on how canonical cell cycle regulators impact on the molecular networks that control the maintenance of pluripotency and lineage specification.

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Host marrow stem cell potential and engraftability at varying times after low-dose whole-body irradiation

Blood ◽

10.1182/blood.v98.4.1246 ◽

2001 ◽

Vol 98 (4) ◽

pp. 1246-1251 ◽

Cited By ~ 25

Author(s):

F. Marc Stewart ◽

Suju Zhong ◽

Jean-François Lambert ◽

Gerald A. Colvin ◽

Mehrdad Abedi ◽

...

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Allogeneic Transplantation ◽

Whole Body ◽

Cell Potential ◽

Stem Cell Expansion ◽

Accessory Cells ◽

Previously Treated ◽

Stem Cell Potential ◽

Predominant Effect

High levels of chimerism in syngeneic BALB/c transplants were reported when hosts were exposed to 1 Gy (100 cGy) whole body irradiation (WBI) and infused with 40 × 106 marrow cells. The recovery of host stem cells and alterations of enhanced host engraftability at varying times after 1 Gy WBI have now been evaluated in this study. Male BALB/c marrow (40 × 106 cells) was infused into female BALB/c hosts immediately or at 6, 12, and 24 weeks after 1 Gy WBI of host female BALB/c mice; engraftment percentages 8 weeks after cell injection at week 0, 6, 12, or 24 were 68% ± 12%, 45% ± 15%, 51% ± 12%, or 20% ± 8%, respectively. Eight-week engraftment levels in nonirradiated hosts average 7.7%. Conversely, engraftable stem cells measured at 8 weeks postengraftment in 1 Gy– exposed hosts were reduced to 8.6% ± 3% of nonirradiated mice at time 0, 35% ± 12% 6 weeks later, 49% ± 10% at 3 months, and 21% ± 7% at 6 months. Engraftment was still increased and stem cell decreased 1 year after 1 Gy. Furthermore, the primary cells transplanted into 1 Gy hosts can be serially transplanted, and the predominant effect of 1 Gy is directly on engrafting stem cells and not through accessory cells. These data show that transplantation in 1 Gy mice may be delayed until recovery of hematopoiesis, suggesting strategies in allogeneic transplantation to avoid the adverse effects of cytokine storm. The incomplete recovery of engraftable stem cells out to 12 months indicates that stem cell expansion, especially in patients previously treated with radiomimetic drugs, may not be feasible.

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The challenges of stem cell therapy

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y2012-016 ◽

2012 ◽

Vol 90 (3) ◽

pp. 273-274 ◽

Cited By ~ 2

Author(s):

Paolo Di Nardo ◽

Dinender Singla ◽

Ren-Ke Li

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Cell Therapy ◽

Stem Cell Therapy ◽

Clinical Setting ◽

Cell Potential ◽

Stem Cell Potential ◽

Insufficient Knowledge

The actual repairing power of stem cells has yet to be fully realized because of insufficient knowledge about the basic mechanisms regulating their fate and unsuitable protocols to implant them in injured tissues. Novel strategies must be formulated to fully exploit stem cell potential in the clinical setting.

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