scholarly journals Estrogen-induced breast cancer is the result of disruption of asymmetric cell division of the stem cell

2010 ◽  
Vol 1 (2) ◽  
Author(s):  
Jose Russo ◽  
Kara Snider ◽  
Julia S. Pereira ◽  
Irma H. Russo
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Type I Collagen ◽  
Asymmetric Cell Division ◽  
Type I ◽  
In Vivo Models ◽  
Pregnancy And Lactation ◽  
In Vitro Systems

AbstractStem cells have the unique potential to divide asymmetrically to generate daughters with distinct fates, one which remains a stem cell and the other which turns into a cell committed to differentiation. By dividing asymmetrically, stem cells maintain the stem cell pool and simultaneously generate committed cells that reconstitute the organ, for example, to prepare the breast for a new pregnancy after involution from a previous pregnancy and lactation process. In addition to the in vivo models of mammary morphogenesis, there are in vitro systems that make the ductulogenic pattern of breast epithelia growth more amenable to study in critically determined conditions. The human breast epithelial cells MCF-10F formed tubules when grown in type I collagen and we demonstrated that treatment of these cells with 17β-estradiol (E

Accept or Reject: The Role of Immune Tolerance in the Development of Stem Cell Therapies and Possible Future Approaches

2020 ◽  
pp. 019262332091824
Author(s):  
Richard Haworth ◽  
Michaela Sharpe
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Embryonic Stem ◽  
Immune Recognition ◽  
Cell Of Origin ◽  
In Vivo Models ◽  
Cell Product ◽  
A Cell

In 2011, Goldring and colleagues published a review article describing the potential safety issues of novel stem cell-derived treatments. Immunogenicity and immunotoxicity of the administered cell product were considered risks in the light of clinical experience of transplantation. The relative immunogenicity of mesenchymal stem cells, embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs) was being addressed through in vitro and in vivo models. But the question arose as to whether the implanted cells needed to be identical to the recipient in every respect, including epigenetically, to evade immune recognition? If so, this set a high bar which may preclude use of many cells derived from iPSCs which have vestiges of a fetal phenotype and epigenetic memory of their cell of origin. However, for autologous iPSCs, the immunogenicity reduces once the surface antigen expression profile becomes close to that of the parent somatic cells. Therefore, a cell product containing incompletely differentiated cells could be more immunogenic. The properties of the administered cells, the immune privilege of the administration site, and the host immune status influence graft success or failure. In addition, the various approaches available to characterize potential immunogenicity of a cell therapy will be discussed.

scholarly journals Human Stem Cell Derived Osteocytes in Bone-on-Chip

MRS Advances ◽  
2018 ◽  
Vol 3 (26) ◽  
pp. 1443-1455
Author(s):  
E. Budyn ◽  
N. Gaci ◽  
S. Sanders ◽  
M. Bensidhoum ◽  
E. Schmidt ◽  
...  
Keyword(s):  
Stem Cell ◽  
Type I Collagen ◽  
Mechanical Load ◽  
Human Bone ◽  
Type I ◽  
Native Bone ◽  
On Chip

ABSTRACTHuman mesenchymal stem cells were reseeded in decellularized human bone subject to a controlled mechanical loading to create a bone-on-chip that was cultured for over 26 months. The cell morphology and their secretome were characterized using immunohistochemistry and in situ immunofluorescence under confocal microscopy. The presence of stem cell derived osteocytes was confirmed at 547 days. Different cell populations were identified. Some cells were connected by long processes and formed a network. Comparison of the MSCs in vitro reorganization and calcium response to in situ mechanical stimulation were compared to MLOY4 cells reseeded on human bone. The bone-on-chip produced an ECM of which the strength was nearly a quarter of native bone after 109 days and that contained calcium minerals at 39 days and type I collagen at 256 days. The cytoplasmic calcium concentration variations seemed to adapt to the expected in vivo mechanical load at the successive stages of cell differentiation in agreement with studies using fluid shear flow stimulation. Some degree of bone-like formation over a long period of time with the formation of a newly formed matrix was observed.

TGF-β signaling–deficient hematopoietic stem cells have normal self-renewal and regenerative ability in vivo despite increased proliferative capacity in vitro

Blood ◽  
2003 ◽  
Vol 102 (9) ◽  
pp. 3129-3135 ◽  
Author(s):  
Jonas Larsson ◽  
Ulrika Blank ◽  
Hildur Helgadottir ◽  
Jon Mar Björnsson ◽  
Mats Ehinger ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Hematopoietic Stem Cells ◽  
Negative Regulator ◽  
Type I ◽  
Hematopoietic Stem ◽  
Knock Out

Abstract Studies in vitro implicate transforming growth factor β (TGF-β) as a key regulator of hematopoiesis with potent inhibitory effects on progenitor and stem cell proliferation. In vivo studies have been hampered by early lethality of knock-out mice for TGF-β isoforms and the receptors. To directly assess the role of TGF-β signaling for hematopoiesis and hematopoietic stem cell (HSC) function in vivo, we generated a conditional knock-out model in which a disruption of the TGF-β type I receptor (TβRI) gene was induced in adult mice. HSCs from induced mice showed increased proliferation recruitment when cultured as single cells under low stimulatory conditions in vitro, consistent with an inhibitory role of TGF-β in HSC proliferation. However, induced TβRI null mice show normal in vivo hematopoiesis with normal numbers and differentiation ability of hematopoietic progenitor cells. Furthermore HSCs from TβRI null mice exhibit a normal cell cycle distribution and do not differ in their ability long term to repopulate primary and secondary recipient mice following bone marrow transplantation. These findings challenge the classical view that TGF-β is an essential negative regulator of hematopoietic stem cells under physiologic conditions in vivo.

scholarly journals STEM-26. SMALL MOLECULE DRUG CBL0137 INHIBITS THE FACT COMPLEX AND SENSITIZES GLIOBLASTOMA CANCER STEM CELLS TO RADIOTHERAPY

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii201-ii202
Author(s):  
Miranda Tallman ◽  
Abigail Zalenski ◽  
Amanda Deighen ◽  
Morgan Schrock ◽  
Sherry Mortach ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
High Rate ◽  
Orthotopic Model ◽  
In Vivo Models ◽  
Specific Cytotoxicity ◽  
Treatment Paradigm ◽  
Cancer Agent

Abstract Glioblastoma (GBM) is a malignant brain tumor with nearly universal recurrence. GBM cancer stem cells (CSCs), a subpopulation of radio- and chemo-resistant cancer cells capable of self-renewal, contribute to the high rate of recurrence. The anti-cancer agent, CBL0137, inhibits the FACT (facilitates chromatin transcription) complex leading to cancer cell specific cytotoxicity. Here, we show that CBL0137 sensitized GBM CSCs to radiotherapy using both in vitro and in vivo models. Treatment of CBL0137 combined with radiotherapy led to increased DNA damage in GBM patient specimens and failure to resolve the damage led to decreased cell viability. Using clonogenic assays, we confirmed that CBL0137 radiosensitized the CSCs. To validate that combination therapy impacted CSCs, we used an in vivo subcutaneous model and showed a decrease in the frequency of cancer stem cells present in tumors as well as decreased tumor volume. Using an orthotopic model of GBM, we confirmed that treatment with CBL0137 followed by radiotherapy led to significantly increased survival compared to either treatment alone. Radiotherapy remains a critical component of patient care for GBM, even though there exists a resistant subpopulation. Radio-sensitizing agents, including CBL0137, pose an exciting treatment paradigm to increase the efficacy of irradiation, especially by inclusively targeting CSCs.

scholarly journals Effects of chitosan-collagen dressing on wound healing in vitro and in vivo assays

2021 ◽  
Vol 19 ◽  
pp. 228080002198969
Author(s):  
Min-Xia Zhang ◽  
Wan-Yi Zhao ◽  
Qing-Qing Fang ◽  
Xiao-Feng Wang ◽  
Chun-Ye Chen ◽  
...  
Keyword(s):  
Wound Healing ◽  
Wound Dressing ◽  
Type I Collagen ◽  
Inhibition Zone ◽  
Negative Control ◽  
Type I ◽  
Nih3t3 Cells ◽  
Post Operation

The present study was designed to fabricate a new chitosan-collagen sponge (CCS) for potential wound dressing applications. CCS was fabricated by a 3.0% chitosan mixture with a 1.0% type I collagen (7:3(w/w)) through freeze-drying. Then the dressing was prepared to evaluate its properties through a series of tests. The new-made dressing demonstrated its safety toward NIH3T3 cells. Furthermore, the CCS showed the significant surround inhibition zone than empty controls inoculated by E. coli and S. aureus. Moreover, the moisture rates of CCS were increased more rapidly than the collagen and blank sponge groups. The results revealed that the CCS had the characteristics of nontoxicity, biocompatibility, good antibacterial activity, and water retention. We used a full-thickness excisional wound healing model to evaluate the in vivo efficacy of the new dressing. The results showed remarkable healing at 14th day post-operation compared with injuries treated with collagen only as a negative control in addition to chitosan only. Our results suggest that the chitosan-collagen wound dressing were identified as a new promising candidate for further wound application.

scholarly journals Regulation of sarcomagenesis by the empty spiracles homeobox genes EMX1 and EMX2

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Manuel Pedro Jimenez-García ◽  
Antonio Lucena-Cacace ◽  
Daniel Otero-Albiol ◽  
Amancio Carnero
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Transcription Factors ◽  
Neural Crest ◽  
Tumor Suppressors ◽  
Homeobox Genes ◽  
Neuronal Cell ◽  
Cell Gene Expression

AbstractThe EMX (Empty Spiracles Homeobox) genes EMX1 and EMX2 are two homeodomain gene members of the EMX family of transcription factors involved in the regulation of various biological processes, such as cell proliferation, migration, and differentiation, during brain development and neural crest migration. They play a role in the specification of positional identity, the proliferation of neural stem cells, and the differentiation of certain neuronal cell phenotypes. In general, they act as transcription factors in early embryogenesis and neuroembryogenesis from metazoans to higher vertebrates. The EMX1 and EMX2’s potential as tumor suppressor genes has been suggested in some cancers. Our work showed that EMX1/EMX2 act as tumor suppressors in sarcomas by repressing the activity of stem cell regulatory genes (OCT4, SOX2, KLF4, MYC, NANOG, NES, and PROM1). EMX protein downregulation, therefore, induced the malignance and stemness of cells both in vitro and in vivo. In murine knockout (KO) models lacking Emx genes, 3MC-induced sarcomas were more aggressive and infiltrative, had a greater capacity for tumor self-renewal, and had higher stem cell gene expression and nestin expression than those in wild-type models. These results showing that EMX genes acted as stemness regulators were reproduced in different subtypes of sarcoma. Therefore, it is possible that the EMX genes could have a generalized behavior regulating proliferation of neural crest-derived progenitors. Together, these results indicate that the EMX1 and EMX2 genes negatively regulate these tumor-altering populations or cancer stem cells, acting as tumor suppressors in sarcoma.

scholarly journals “Empowering” Cardiac Cells via Stem Cell Derived Mitochondrial Transplantation- Does Age Matter?

2021 ◽  
Vol 22 (4) ◽  
pp. 1824
Author(s):  
Matthias Mietsch ◽  
Rabea Hinkel
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Treatment Strategies ◽  
Cardiac Cells ◽  
Aging Effects ◽  
Beneficial Effects ◽  
Micro Rnas ◽  
New Treatment

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.

P-EP013. Superior migration propensity of dental pulp stem cells in in vitro and in vivo models of excitotoxic neurodegeneration

2021 ◽  
Vol 132 (8) ◽  
pp. e82-e83
Author(s):  
Sivapriya Senthilkumar ◽  
Chaitra Venugopal ◽  
K. Shobha ◽  
Bindu M. Kutty ◽  
Anandh Dhanushkodi
Keyword(s):  
Stem Cells ◽  
Dental Pulp ◽  
Dental Pulp Stem Cells ◽  
In Vivo Models ◽  
Migration Propensity

Vitamin K promotes mineralization, osteoblast-to-osteocyte transition, and an anticatabolic phenotype by γ-carboxylation-dependent and -independent mechanisms

2009 ◽  
Vol 297 (6) ◽  
pp. C1358-C1367 ◽  
Author(s):  
Gerald J. Atkins ◽  
Katie J. Welldon ◽  
Asiri R. Wijenayaka ◽  
Lynda F. Bonewald ◽  
David M. Findlay
Keyword(s):  
Bone Formation ◽  
Vitamin K ◽  
Type I Collagen ◽  
Vitamin K2 ◽  
Type I ◽  
Vitamin K1 ◽  
Vitamin K3 ◽  
Positive Effect

The vitamin K family members phylloquinone (vitamin K1) and the menaquinones (vitamin K2) are under study for their roles in bone metabolism and as potential therapeutic agents for skeletal diseases. We have investigated the effects of two naturally occurring homologs, phytonadione (vitamin K1) and menatetrenone (vitamin K2), and those of the synthetic vitamin K, menadione (vitamin K3), on human primary osteoblasts. All homologs promoted in vitro mineralization by these cells. Vitamin K1-induced mineralization was highly sensitive to warfarin, whereas that induced by vitamins K2 and K3 was less sensitive, implying that γ-carboxylation and other mechanisms, possibly genomic actions through activation of the steroid xenobiotic receptor, are involved in the effect. The positive effect on mineralization was associated with decreased matrix synthesis, evidenced by a decrease from control in expression of type I collagen mRNA, implying a maturational effect. Incubation in the presence of vitamin K2 or K3 in a three-dimensional type I collagen gel culture system resulted in increased numbers of cells with elongated cytoplasmic processes resembling osteocytes. This effect was not warfarin sensitive. Addition of calcein to vitamin K-treated cells revealed vitamin K-dependent deposition of mineral associated with cell processes. These effects are consistent with vitamin K promoting the osteoblast-to-osteocyte transition in humans. To test whether vitamin K may also act on mature osteocytes, we tested the effects of vitamin K on MLO-Y4 cells. Vitamin K reduced receptor activator of NF-κB ligand expression relative to osteoprotegerin by MLO-Y4 cells, an effect also seen in human cultures. Together, our findings suggest that vitamin K promotes the osteoblast-to-osteocyte transition, at the same time decreasing the osteoclastogenic potential of these cells. These may be mechanisms by which vitamin K optimizes bone formation and integrity in vivo and may help explain the net positive effect of vitamin K on bone formation.

Cells in regenerating deer antler cartilage provide a microenvironment that supports osteoclast differentiation

2001 ◽  
Vol 204 (3) ◽  
pp. 443-455
Author(s):  
C. Faucheux ◽  
S. Nesbitt ◽  
M. Horton ◽  
J. Price
Keyword(s):  
Type I Collagen ◽  
Mononuclear Cells ◽  
Osteoclast Differentiation ◽  
Cathepsin K ◽  
Collagen Matrix ◽  
Tartrate Resistant Acid Phosphatase ◽  
Type I ◽  
Deer Antler

Deer antlers are a rare example of mammalian epimorphic regeneration. Each year, the antlers re-grow by a modified endochondral ossification process that involves extensive remodelling of cartilage by osteoclasts. This study identified regenerating antler cartilage as a site of osteoclastogenesis in vivo. An in vitro model was then developed to study antler osteoclast differentiation. Cultured as a high-density micromass, cells from non-mineralised cartilage supported the differentiation of large numbers of osteoclast-like multinucleated cells (MNCs) in the absence of factors normally required for osteoclastogenesis. After 48 h of culture, tartrate-resistant acid phosphatase (TRAP)-positive mononuclear cells (osteoclast precursors) were visible, and by day 14 a large number of TRAP-positive MNCs had formed (783+/−200 per well, mean +/− s.e.m., N=4). Reverse transcriptase/polymerase chain reaction (RT-PCR) showed that receptor activator of NF κ B ligand (RANKL) and macrophage colony stimulating factor (M-CSF) mRNAs were expressed in micromass cultures. Antler MNCs have the phenotype of osteoclasts from mammalian bone; they expressed TRAP, vitronectin and calcitonin receptors and, when cultured on dentine, formed F-actin rings and large resorption pits. When cultured on glass, antler MNCs appeared to digest the matrix of the micromass and endocytose type I collagen. Matrix metalloproteinase-9 (MMP-9) may play a role in the resorption of this non-mineralised matrix since it is highly expressed in 100 % of MNCs. In contrast, cathepsin K, another enzyme expressed in osteoclasts from bone, is only highly expressed in resorbing MNCs cultured on dentine. This study identifies the deer antler as a valuable model that can be used to study the differentiation and function of osteoclasts in adult regenerating mineralised tissues.

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