scholarly journals In vitro Assessment of the DNA Damage Response in Dental Mesenchymal Stromal Cells Following Low Dose X-ray Exposure

2021 ◽  
Vol 9 ◽  
Author(s):  
Niels Belmans ◽  
Liese Gilles ◽  
Jonas Welkenhuysen ◽  
Randy Vermeesen ◽  
Bjorn Baselet ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Cell Cycle Progression ◽  
Deciduous Teeth ◽  
Low Doses ◽  
Cycle Progression ◽  
X Ray

Stem cells contained within the dental mesenchymal stromal cell (MSC) population are crucial for tissue homeostasis. Assuring their genomic stability is therefore essential. Exposure of stem cells to ionizing radiation (IR) is potentially detrimental for normal tissue homeostasis. Although it has been established that exposure to high doses of ionizing radiation (IR) has severe adverse effects on MSCs, knowledge about the impact of low doses of IR is lacking. Here we investigated the effect of low doses of X-irradiation with medical imaging beam settings (<0.1 Gray; 900 mGray per hour), in vitro, on pediatric dental mesenchymal stromal cells containing dental pulp stem cells from deciduous teeth, dental follicle progenitor cells and stem cells from the apical papilla. DNA double strand break (DSB) formation and repair kinetics were monitored by immunocytochemistry of γH2AX and 53BP1 as well as cell cycle progression by flow cytometry and cellular senescence by senescence-associated β-galactosidase assay and ELISA. Increased DNA DSB repair foci, after exposure to low doses of X-rays, were measured as early as 30 min post-irradiation. The number of DSBs returned to baseline levels 24 h after irradiation. Cell cycle analysis revealed marginal effects of IR on cell cycle progression, although a slight G2/M phase arrest was seen in dental pulp stromal cells from deciduous teeth 72 h after irradiation. Despite this cell cycle arrest, no radiation-induced senescence was observed. In conclusion, low X-ray IR doses (< 0.1 Gray; 900 mGray per hour), were able to induce significant increases in the number of DNA DSBs repair foci, but cell cycle progression seems to be minimally affected. This highlights the need for more detailed and extensive studies on the effects of exposure to low IR doses on different mesenchymal stromal cells.

scholarly journals Stroma-Derived Connective Tissue Growth Factor Maintains Cell Cycle Progression and Repopulation Activity of Hematopoietic Stem Cells In Vitro

2015 ◽  
Vol 5 (5) ◽  
pp. 702-715 ◽  
Author(s):  
Rouzanna Istvánffy ◽  
Baiba Vilne ◽  
Christina Schreck ◽  
Franziska Ruf ◽  
Charlotta Pagel ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Growth Factor ◽  
Connective Tissue ◽  
Hematopoietic Stem Cells ◽  
Cell Cycle Progression ◽  
Tissue Growth ◽  
Cycle Progression ◽  
Hematopoietic Stem

Connective Tissue Growth Factor (Ctgf/Ccn2) Is a Novel Extrinsic Niche-Derived Regulator Of Hematopoietic Stem Cells

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3688-3688
Author(s):  
Baiba Vilne ◽  
Rouzanna Istvanffy ◽  
Christina Eckl ◽  
Franziska Bock ◽  
Sandra Grziwok ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Wnt Signaling ◽  
Stromal Cells ◽  
Cell Cycle Progression ◽  
Tissue Growth ◽  
Cycle Progression ◽  
Hematopoietic Stem ◽  
Canonical Wnt

Abstract Hematopoietic stem cells (HSC) are regulated by an interplay of intrinsic and extrinsic signals, the latter of which are mostly transmitted by the niche. The processes involved and their interactions are largely unknown. We studied the dynamic interaction of HSC and niche stromal cells, using co-cultures of HSC (lineage-negative Sca-1+ c-Kit+: LSK) cells and HSC-maintaining UG26-1B6 stromal cells. Microarray analyses from cells prior to co-culture and cells sorted separately from the cultures revealed that most changes in gene expression take place in the first 24 hours of co-culture. Analyses using STEM clustering, LIMMA, and ToppGene databases showed early activation of cell cycle progression In LSK cells and extensive remodeling of chomatin structure and transcriptional activation in both LSK and stromal cells. Interestingly, connective tissue growth factor (Ctgf/Ccn2), which is involved in TGFb, BMP and Wnt signaling, was strongly upregulated in both stromal and LSK cells. To study the role of Ctgf as a stromal mediator, LSK cells were co-cultured with siCTGF knockdown stromal cells. We showed that although short-term HSC activity was unchanged, siCtgf-stromal cells were unable to sustain long-term repopulating ability. To study underlying mechanisms, a Boolean model simulating possible signaling mechanisms leading to cell cycle activation was extracted from the data. We validated this model by co-cultures of LSK cells with control and Ctgf-knockdown stroma, separating LSK and stromal cells and assessing protein levels and phosphorylation using immunocytofluorescence in LSK cells. We found that in the absence of extrinsic Ctgf, expression of Pten was increased in LSK cells. However, phosphorylation of Akt (both p308, and p473) and Erk was unchanged. In contrast, both canonical Wnt (LRP6, Gsk3b, b-catenin) and Tgfb (Smad2/3) signaling were significantly affected in that Wnt signaling was turned off, whereas Tgf signaling was turned on, by the lack of extrinsic Ctgf. This resulted in a downregulation of G1 transition, as was exemplified by downregulation of Cyclin D1, upregulation of p27Kip1 and modulations in the phosphoryalation of both Rb and p53. Equally interestingly, we could show that extrinsic Ctgf deficiency also downregulates induction of Ctgf in HSC, suggesting the existence of intrinsic-extrinsic feedback signaling. In summary, co-culture of LSK cells with stromal cells results in cellular activation of both stromal cells and LSK cells, involving Tgf and canonical Wnt signaling pathways. Furthermore, reduced expression of extrinsic Ctgf, regulates mediators of G1 cell cycle progression in LSK cells an a biochemical level and functionally results in an increased production of myeloid progenitors and decreased long-term repopulating ability. Our studies show the dynamics of reciprocal signaling between HSC and niche stromal cells and give insights how the niche regulates early regenerative responses in hematopoiesis. Disclosures: No relevant conflicts of interest to declare.

scholarly journals LMNB2 promotes the progression of colorectal cancer by silencing p21 expression

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Chen-Hua Dong ◽  
Tao Jiang ◽  
Hang Yin ◽  
Hu Song ◽  
Yi Zhang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Progression ◽  
Molecular Mechanisms ◽  
Gene Set Enrichment Analysis ◽  
Molecular Therapy ◽  
Cycle Progression ◽  
Cancer Tissues

AbstractColorectal cancer is the second common cause of death worldwide. Lamin B2 (LMNB2) is involved in chromatin remodeling and the rupture and reorganization of nuclear membrane during mitosis, which is necessary for eukaryotic cell proliferation. However, the role of LMNB2 in colorectal cancer (CRC) is poorly understood. This study explored the biological functions of LMNB2 in the progression of colorectal cancer and explored the possible molecular mechanisms. We found that LMNB2 was significantly upregulated in primary colorectal cancer tissues and cell lines, compared with paired non-cancerous tissues and normal colorectal epithelium. The high expression of LMNB2 in colorectal cancer tissues is significantly related to the clinicopathological characteristics of the patients and the shorter overall and disease-free cumulative survival. Functional analysis, including CCK8 cell proliferation test, EdU proliferation test, colony formation analysis, nude mouse xenograft, cell cycle, and apoptosis analysis showed that LMNB2 significantly promotes cell proliferation by promoting cell cycle progression in vivo and in vitro. In addition, gene set enrichment analysis, luciferase report analysis, and CHIP analysis showed that LMNB2 promotes cell proliferation by regulating the p21 promoter, whereas LMNB2 has no effect on cell apoptosis. In summary, these findings not only indicate that LMNB2 promotes the proliferation of colorectal cancer by regulating p21-mediated cell cycle progression, but also suggest the potential value of LMNB2 as a clinical prognostic marker and molecular therapy target.

871 In vitro immunoregulatory effect from cervical cancer derived mesenchymal stromal cells over molecules expression in monocyte derived macrophage polarization

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A923-A923
Author(s):  
Víctor Cortés-Morales ◽  
Juan Montesinos ◽  
Luis Chávez-Sánchez ◽  
Sandra Espíndola-Garibay ◽  
Alberto Monroy-García ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Stem Cells ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Macrophage Polarization ◽  
Induction Medium ◽  
M2 Macrophage ◽  
List Type ◽  
M2 Phenotype

BackgroundMacrophages are immunological cells that sense microenvironmental signals that may result in the polarized expression of either proinflammatory (M1) or anti-inflammatory (M2) phenotype.1 Macrophages M2 are present in tumoral microenvironment and their presence in patients with cervical cancer (CeCa) is related with less survival.2Mesenchymal Stromal Cells (MSCs) are also present in tumor microenvironment of cervical cancer (CeCa-MSC), which have shown immunoregulatory effects over CD8 T cells, decreasing their cytotoxic effect against tumoral cells.3 Interestingly, MSCs from bone marrow (BM-MSC) decrease M1 and increase M2 macrophage polarization in an in vitro coculture system.4 Macrophages and MSCs are present in microenvironment of cervical cancer, however it is unknown if MSCs play a role in macrophage polarization. In the present study, we have evaluated the immunoregulatory capacity of CeCa-MSCs to induce macrophage polarization.MethodsCD14 monocytes were isolated from peripheral blood and cultivated in the absence or presence of MSCs from BM, normal cervix (NCx) and CeCa. Two culture conditions were included, in the presence of induction medium to favors M1 (GM-CSF, LPS and IFNg) or M2 (M-CSF, IL-4 and IL-13) macrophage polarization. M1 (HLA-DR, CD80, CD86 and IFNg) or M2 (CD14, CD163, CD206, IDO and IL-10) macrophage molecular markers were evaluated by flow cytometry. Finally, we evaluated concentration of IL-10 and TNFa in conditioned medium form all coculture conditions.ResultsWe observed that CeCa-MSCs and BM-MSCs in presence of M1 induction medium, decreased M1 macrophage markers (HLA-II, CD80, CD86 and IFNg), and increase the expression of CD14 (M2 macrophage marker). Interestingly, in presence of M2 induction medium, BM-MSCs and CaCe-MSCs but not CxN-MSC increased CD163, CD206, IDO and IL-10 (M2 macrophage markers). We observed a decreased concentration of TNFa in the supernatant medium from all cocultures with MSCs, but only in presence of CeCa-MSCs, increased IL-10 concentration was detected in such cocultures.ConclusionsIn contrast to NCx-MSCs, CeCa-MSCs similarly to BM-MSCs have in vitro capacity to decrease M1 and increase M2 macrophage phenotype.AcknowledgementsAcknowledgments The authors are indebted to gratefully acknowledge to CONACYT (Grant No. 272793) and IMSS (Grant no. 1731) for support to Juan J. Montesinos research.ReferencesMartinez FO, Gordon S. The M1 and M2 paradigm of macrophage activation: time for reassessment. F1000Prime Rep 2014;6-13.Petrillo M, Zannoni GF, Martinelli E, et al. Polarization of tumor-associated macrophages toward M2 phenotype correlates with poor response to chemoradiation and reduced survival in patients with locally advanced cervical cancer. PLoS One 2015;10: e0136654.Montesinos JJ, Mora-García Mde L, et al. In vitro evidence of the presence of mesenchymal stromal cells in cervical cancer and their role in protecting cancer cells from cytotoxic T cell activity. Stem Cells Dev 2013;22:2508-2519.Vasandan AB, Jahnavi S, Shashank C. Human mesenchymal stem cells program macrophage plasticity by altering their metabolic status via a PGE 2-dependent mechanism. Sci Rep 2016;6:38308.

scholarly journals Molecular cloning of a novel mitogen-inducible nuclear protein with a Ran GTPase-activating domain that affects cell cycle progression.

1995 ◽  
Vol 15 (1) ◽  
pp. 552-560 ◽  
Author(s):  
M Hattori ◽  
N Tsukamoto ◽  
M S Nur-e-Kamal ◽  
B Rubinfeld ◽  
K Iwai ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Nuclear Protein ◽  
Interleukin 2 ◽  
Quiescent State ◽  
Cycle Progression ◽  
Ran Gtpase ◽  
G0 Phase ◽  
Nih 3T3

We have cloned a novel cDNA (Spa-1) which is little expressed in the quiescent state but induced in the interleukin 2-stimulated cycling state of an interleukin 2-responsive murine lymphoid cell line by differential hybridization. Spa-1 mRNA (3.5 kb) was induced in normal lymphocytes following various types of mitogenic stimulation. In normal organs it is preferentially expressed in both fetal and adult lymphohematopoietic tissues. A Spa-1-encoded protein of 68 kDa is localized mostly in the nucleus. Its N-terminal domain is highly homologous to a human Rap1 GTPase-activating protein (GAP), and a fusion protein of this domain (SpanN) indeed exhibited GAP activity for Rap1/Rsr1 but not for Ras or Rho in vitro. Unlike the human Rap1 GAP, however, SpanN also exhibited GAP activity for Ran, so far the only known Ras-related GTPase in the nucleus. In the presence of serum, stable Spa-1 cDNA transfectants of NIH 3T3 cells (NIH/Spa-1) hardly overexpressed Spa-1 (p68), and they grew as normally as did the parental cells. When NIH/Spa-1 cells were serum starved to be arrested in the G1/G0 phase of the cell cycle, however, they, unlike the control cells, exhibited progressive Spa-1 p68 accumulation, and following the addition of serum they showed cell death resembling mitotic catastrophes of the S phase during cell cycle progression. The results indicate that the novel nuclear protein Spa-1, with a potentially active Ran GAP domain, severely hampers the mitogen-induced cell cycle progression when abnormally and/or prematurely expressed. Functions of the Spa-1 protein and its regulation are discussed in the context of its possible interaction with the Ran/RCC-1 system, which is involved in the coordinated nuclear functions, including cell division.

scholarly journals High Mobility Group A1 Chromatin Regulators Function As Critical Drivers of Leukemogenesis in Preclinical Models of Relapsed, Pediatric B-Cell ALL

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3946-3946
Author(s):  
Liping Li ◽  
Katharina Hayer ◽  
Lingling Xian ◽  
Li Luo ◽  
Leslie Cope ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Lines ◽  
Cell Cycle Progression ◽  
High Mobility ◽  
Transcriptional Networks ◽  
Rna Seq ◽  
Cycle Progression ◽  
Short Hairpin ◽  
Reh Cells

Introduction: Acute B-cell lymphoblastic leukemia (B-ALL) is the most common form of childhood leukemia and the leading cause of death in children with cancer. While therapy is often curative, about 10-15% of children will relapse with recurrent disease and abysmal outcomes. Actionable mechanisms that mediate relapse remain largely unknown. The gene encoding the High Mobility Group A1(HMGA1) chromatin regulator is overexpressed in diverse malignancies where high levels portend poor outcomes. In murine models, we discovered thatHmga1 overexpression is sufficient for clonal expansion and progression to aggressive acute lymphoid leukemia (Cancer Res 2008,68:10121, 2018,78:1890; Nature Comm 2017,8:15008). Further, HMGA1 is overexpressed in pediatric B-ALL (pB-ALL) blasts with highest levels in children who relapse early compared to those who achieve chronic remissions. Together, these findings suggest that HMGA1 is required for leukemogenesis and may foster relapse in B-ALL. We therefore sought to: 1) test the hypothesis that HMGA1 is a key epigenetic regulator required for leukemogenesis and relapse in pB-ALL, and, 2) elucidate targetable mechanisms mediated by HMGA1 in leukemogenesis. Methods: We silenced HMGA1 via lentiviral delivery of short hairpin RNAs targeting 2 different sequences in cell lines derived from relapsed pB-ALL (REH, 697). REH cells harbor the TEL-AML1 fusion; 697 cells express BCL2, BCL3, and cMYC. Next, we assessed leukemogenic phenotypes in vitro (proliferation, cell cycle progression, apoptosis, and clonogenicity) and leukemogenesis invivo. To dissect molecular mechanisms underlying HMGA1, we performed RNA-Seq and applied in silico pathway analysis. Results: There is abundant HMGA1 mRNA and protein in both pB-ALL cell lines and HMGA1 was effectively silenced by short hairpin RNA. Further, silencing HMGA1 dramatically halts proliferation in both cell lines, leading to a decrease in cells in S phase with a concurrent increase in G0/S1. Apoptosis also increased by 5-10% after HMGA1 silencing based on flow cytometry for Annexin V. In colony forming assays, silencing HMGA1 impaired clonogenicity in both pB-ALL cell lines. To assess HMGA1 function in leukemogenesis in vivo, we implanted control pB-ALL cells (transduced with control lentivirus) or those with HMGA1 silencing via tail vein injection into immunosuppressed mice (NOD/SCID/IL2 receptor γ). All mice receiving control REH cells succumbed to leukemia with a median survival of only 29 days. At the time of death, mice had marked splenomegaly along with leukemic cells circulating in the peripheral blood and infiltrating both the spleen and bone marrow. In contrast, mice injected with REH cells with HMGA1 silencing survived for >40 days (P<0.001) and had a significant decrease in tumor burden in the peripheral blood, spleen, and bone marrow. Similar results were obtained with 697 cells, although this model was more fulminant with control mice surviving for a median of only 17 days. To determine whether the leukemic blasts found in mice injected with ALL cells after HMGA1 silencing represented a clone that expanded because it escaped HMGA1 silencing, we assessed HMGA1 levels and found that cells capable of establishing leukemia had high HMGA1 expression, with levels similar to those observed in control cells without HMGA1 silencing. RNA-Seq analyses from REH and 697 cell lines with and without HMGA1 silencing revealed that HMGA1 up-regulates transcriptional networks involved in RAS/MAPK/ERK signaling while repressing the IDH1 metabolic gene, the latter of which functions in DNA and histone methylation. Studies are currently underway to identify effective agents to target HMGA1 pathways. Conclusions: Silencing HMGA1 dramatically disrupts leukemogenic phenotypes in vitro and prevents the development of leukemia in mice. Mechanistically, RNA-Seq analyses revealed that HMGA amplifies transcriptional networks involved cell cycle progression and epigenetic modifications. Our findings highlight the critical role for HMGA1 as a molecular switch required for leukemic transformation in pB-ALL and a rational therapeutic target that may be particularly relevant for relapsed B-ALL. Disclosures No relevant conflicts of interest to declare.

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