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1.
Stem Cells ; 41(1): 93-104, 2023 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-36368017

RESUMO

While supplemental angiopoietin-1 (Ang1) improves hematopoiesis, excessive Ang1 induces bone marrow (BM) impairment, hematopoietic stem cell (HSC) senescence, and erythropoietic defect. Here, we examined how excessive Ang1 disturbs hematopoiesis and explored whether hematopoietic defects were related to its level using K14-Cre;c-Ang1 and Col2.3-Cre;c-Ang1 transgenic mice that systemically and locally overexpress cartilage oligomeric matrix protein-Ang1, respectively. We also investigated the impacts of Tie2 inhibitor and AMD3100 on hematopoietic development. Transgenic mice exhibited excessive angiogenic phenotypes, but K14-Cre;c-Ang1 mice showed more severe defects in growth and life span with higher presence of Ang1 compared with Col2.3-Cre;c-Ang1 mice. Dissimilar to K14-Cre;c-Ang1 mice, Col2.3-Cre;c-Ang1 mice did not show impaired BM retention or senescence of HSCs, erythropoietic defect, or disruption of the stromal cell-derived factor 1 (SDF-1)/CXCR4 axis. However, these mice exhibited a defect in platelet production depending on the expression of Tie2 and globin transcription factor 1 (GATA-1), but not GATA-2, in megakaryocyte progenitor (MP) cells. Treatment with Tie2 inhibitor recovered GATA-1 expression in MP cells and platelet production without changes in circulating RBC in transgenic mice. Consecutive AMD3100 administration not only induced irrecoverable senescence of HSCs but also suppressed formation of RBC, but not platelets, via correlated decreases in number of erythroblasts and their GATA-1 expression in B6 mice. Our results indicate that genetic overexpression of Ang1 impairs hematopoietic development depending on its level, in which megakaryopoiesis is preferentially impaired via activation of Ang1/Tie2 signaling, whereas erythropoietic defect is orchestrated by HSC senescence, inflammation, and disruption of the SDF-1/CXCR4 axis.


Assuntos
Anemia , Trombocitopenia , Camundongos , Animais , Proteína de Matriz Oligomérica de Cartilagem/genética , Angiopoietina-1/genética , Angiopoietina-1/metabolismo , Quimiocina CXCL12/genética , Quimiocina CXCL12/metabolismo , Camundongos Transgênicos , Anemia/genética , Receptor TIE-2/genética , Receptor TIE-2/metabolismo
2.
Stem Cells ; 39(1): 103-114, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33038284

RESUMO

Although functional association between Wnt signaling and bone homeostasis has been well described through genetic ablation of Wntless (Wls), the mechanisms of how osteoblastic Wls regulates the fate of bone marrow stromal cells (BMSCs) and hematopoietic stem cells (HSCs) in relation to age are not yet understood. Here, we generated Col2.3-Cre;Wlsfl/fl mice that were free from premature lethality and investigated age-related impacts of osteoblastic Wls deficiency on hematopoiesis, BM microenvironment, and maintenance of BMSCs (also known as BM-derived mesenchymal stem/stromal cells) and HSCs. Ablation of osteoblastic Wls deteriorated BM microenvironment and bone mass accrual along with age-independent effects on functions of BMSCs. Osteoblastic Wls deletion impaired HSC repopulation and progeny with skewing toward myeloid lineage cells only at old stage. As proven by hallmarks of stem cell senescence, osteoblastic Wls ablation differentially induced senescence of BMSCs and HSCs in relation to age without alteration in their BM frequency. Our findings support that deletion of Wls in Col2.3-expressing cells induces senescence of BMSCs and impairs BM microenvironment in age-independent manner. Overall, long-term deterioration in BM microenvironment contributes to age-related HSC senescence with impaired progeny and hematopoiesis, which also suggests possible roles of osteoblastic Wls on the maintenance of BM HSCs.


Assuntos
Envelhecimento/metabolismo , Células da Medula Óssea/metabolismo , Deleção de Genes , Osteoblastos/metabolismo , Receptores Acoplados a Proteínas G/deficiência , Células-Tronco/metabolismo , Animais , Camundongos , Camundongos Transgênicos , Receptores Acoplados a Proteínas G/metabolismo
3.
J Periodontal Res ; 54(6): 690-701, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31328274

RESUMO

OBJECTIVE: Dietary bioactive materials having anti-inflammatory and antioxidant potentials are able to inhibit diabetes-associated periodontal complications. Although numerous studies indicate that administration of p-coumaric acid (p-CA) ameliorates diabetes and diabetes-related complications, the roles of p-CA on periodontal tissue destruction in diabetic mice and the possible mechanisms therein are not completely understood. In this study, we evaluated whether supplementation with p-CA protects mice against diabetes-associated spontaneous periodontal destruction and also explored the associated mechanism therein using in vivo and in vitro experimental systems. MATERIALS AND METHODS: C57BL/6 male mice were divided into sham, streptozotocin (STZ), and STZ+CA groups (n = 5/group). Sham group was intraperitoneally injected with sodium buffer, whereas other two groups were injected with the buffer containing 160 mg/kg of STZ. STZ-induced diabetic mice received oral gavage with p-CA (50 mg/kg) (STZ+CA group) or with buffer only (STZ group) daily for 6 weeks. The effect of p-CA on diabetes-associated spontaneous periodontal destruction was evaluated using µCT analysis, hematoxylin and eosin staining, tartrate-resistant acid phosphatase staining, and immunohistochemical staining methods. The efficacies of p-CA on cell proliferation, osteoblast differentiation, reactive oxygen species (ROS) accumulation, and antioxidant-related marker expression were examined using human periodontal ligament fibroblasts (hPLFs) cultured under high glucose condition. RESULTS: Streptozotocin group exhibited periodontal tissue destruction along with increased inflammation, oxidative stress, and osteoclast formation, as well as with decreased osteogenesis. However, oral administration with p-CA protected mice against STZ-induced periodontal destruction by inhibiting inflammation and osteoclastic activation. STZ+CA group also showed higher expression of antioxidant and osteogenic markers in periodontal tissue than did STZ group. Treatment with high glucose concentration (30 mmol/L) impaired proliferation and osteoblast differentiation of hPLFs along with cellular ROS accumulation, whereas these impairments were almost completely disappeared by supplementation with p-CA. CONCLUSION: These findings demonstrate that supplementation with p-CA inhibits diabetes-associated spontaneous destruction of periodontal tissue by enhancing anti-inflammatory, anti-osteoclastogenic, and antioxidant defense systems in STZ-treated mice.


Assuntos
Diabetes Mellitus Experimental/complicações , Suplementos Nutricionais , Estresse Oxidativo , Doenças Periodontais/tratamento farmacológico , Propionatos/farmacologia , Administração Oral , Animais , Antioxidantes/metabolismo , Células Cultivadas , Ácidos Cumáricos , Fibroblastos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Doenças Periodontais/etiologia , Ligamento Periodontal/citologia , Estreptozocina
4.
Biochem Biophys Res Commun ; 499(3): 669-674, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29604278

RESUMO

Supplemental Angiopoietin 1 (Ang1) exerts its therapeutic potential on microvascular regression-associated diseases, and this potential is linked with the function of hematopoietic stem cells (HSCs). However, the underlying mechanisms of the effect of enhanced angiogenesis on the modulation of HSCs are not yet defined. Here, we generated transgenic mice expressing Cartilage Oligomeric Matrix Protein (COMP)-Ang1 in keratin 14-expressing cells. The mutant animals expressed excessive angiogenic characteristics in the skin and bone marrow (BM) along with redder skin with more numerous and branched vessels compared with their wild-type (WT) littermates. The mutants displayed reduced long bone formation and osteoclast activity than did WT littermates and had fewer CD150+CD48-Lineage-Sca-1+c-Kit+ (LSK) cells in the BM. The mutants also exhibited greater senescence-associated (SA) ß-gal activity, p16INK4a protein expression, and superoxide anion levels in CD150+CD48-LSK cells in the BM. Furthermore, transplantation assay revealed that the mutant-derived LSK cells were inferior to the cells derived from WT littermate in inducing competitive repopulating capacity in the recipients. Collectively, our results demonstrate that persistent and prolonged administration of COMP-Ang1 by inducible transgenic expression mediates excessive angiogenesis in the body and impairs BM microenvironment, eventually leading to senescence of BM HSCs.


Assuntos
Angiopoietina-1/genética , Medula Óssea/metabolismo , Proteína de Matriz Oligomérica de Cartilagem/genética , Microambiente Celular , Senescência Celular , Expressão Gênica , Células-Tronco Hematopoéticas/metabolismo , Proteínas Recombinantes de Fusão/genética , Animais , Proteína de Matriz Oligomérica de Cartilagem/metabolismo , Células-Tronco Hematopoéticas/citologia , Humanos , Camundongos Transgênicos , Mutação/genética , Neovascularização Fisiológica , Osteoclastos , Proteínas Recombinantes de Fusão/metabolismo
5.
Stem Cells ; 34(10): 2601-2607, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27300755

RESUMO

Osteoclasts form a bone marrow (BM) cavity serving as a hematopoietic niche for the maintenance of hematopoietic stem cells (HSCs). However, the role of osteoclasts in the BM has been controversially reported and remains to be further understood. In the present study, we investigated how osteoclasts affect the modulation of hematopoietic stem/progenitor cells in the BM by administering bisphosphate alendronate (ALN) to B6 mice for 21 consecutive days to inhibit osteoclast activity. ALN treatment caused a reduction in the number of tartrate-resistant acid phosphate (TRAP)-positive osteoclast cells and an increase in bone mineral density, particularly in the trabecular zone, but not in the cortical zone of the BM. Osteoclast inhibition caused by ALN treatment decreased mitochondrial reactive oxygen species (ROS) generation and SA-ß-gal activity of CD150+ CD48- Lineage-Sca-1+ c-Kit+ (LSK) cells, eventually leading to an improvement in the engraftment potential and self-renewal activity of HSCs. Moreover, ALN-treated mice exhibited an enhanced resistance of HSCs in response to the genotoxic stress of 5-fluorouracil, as determined by mitochondrial ROS generation, SA-ß-gal activity, and p16INK4a expression in subsets of LSK and CD150+ CD48- LSK cells as well as competitive assay. Collectively, our findings indicate that inhibition of osteoclast activity improves the long-term engraftment potential and stress resistance of HSCs. Stem Cells 2016;34:2601-2607.


Assuntos
Alendronato/administração & dosagem , Alendronato/farmacologia , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/citologia , Osteoclastos/metabolismo , Estresse Fisiológico , Animais , Antineoplásicos/efeitos adversos , Densidade Óssea/efeitos dos fármacos , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Osso Esponjoso/efeitos dos fármacos , Osso Esponjoso/fisiologia , Autorrenovação Celular/efeitos dos fármacos , Feminino , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Camundongos Endogâmicos C57BL , Osteoclastos/efeitos dos fármacos , Células-Tronco de Sangue Periférico/citologia , Baço/citologia , Estresse Fisiológico/efeitos dos fármacos , Fatores de Tempo
6.
J Bone Miner Metab ; 35(5): 485-496, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27766421

RESUMO

Fibroblast growth factor 7 (FGF7) plays an important role in regulating the proliferation, migration, and differentiation of cells. However, the role of FGF7 in bone formation is not yet fully understood. We examined the effect of FGF7 on bone formation using a rat model of mandible defects. Rats underwent mandible defect surgery and then either scaffold treatment alone (control group) or FGF7-impregnated scaffold treatment (FGF7 group). Micro-CT and histological analyses revealed that the FGF7 group exhibited greater bone formation than did the control group 10 weeks after surgery. With the exception of total porosity (%), all bone parameters had higher values in the FGF7 group than in the control group at each follow-up after surgery. The FGF7 group showed greater expression of osteogenic markers, such as runt-related transcription factor 2, osterix, osteocalcin, bone morphogenetic protein 2, osteopontin, and type I collagen in newly formed bone than did the control group. The delivery of FGF7 also increased the messenger RNA expression of stromal-cell-derived factor 1 (SDF-1) and CXCR4 in newly formed bone in the FGF7 group compared with the control group. Further, addition of exogenous FGF7 induced migration of rat bone marrow stromal cells and increased the expression of SDF-1 and CXCR4 in the cells. Furthermore, the addition of FGF7 augmented mineralization in the cells with increased expression of osteogenic markers, and this augmentation was significantly suppressed by an inhibitor specific for c-Jun N-terminal kinase (SP600125) or extracellular-signal-regulated kinase (PD98059). Collectively, these results suggest that local delivery of FGF7 increases bone formation in a mandible defect with enhanced osteogenesis and chemoattraction.

7.
Mol Cell Biochem ; 416(1-2): 157-68, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27107990

RESUMO

Recombinant COMP-Ang1, a chimera of angiopoietin-1 (Ang1), and a short coiled-coil domain of cartilage oligomeric matrix protein (COMP) can stimulate multiple cellular processes. Proliferative capacity of periodontal ligament (PDL) fibroblasts (PLFs) is important for maintaining PDL integrity and homeostasis. In this study, we explored whether exogenous COMP-Ang1 addition enhances proliferation of human PLFs and the cellular mechanisms therein. We initially isolated and characterized PLFs, where the cells showed highly positive staining for surface markers, CD90, CD105, and CD146. COMP-Ang1 treatment increased proliferation of PLFs by stimulating migration of cells into S and G2/M phases. This increase was coupled with decreased p21(Cip) and p27(Kip) levels and enhanced cyclin D1, cyclin-dependent kinase (CDK) 2, and CDK4 induction. Transfection with si-Tie2 near completely blocked COMP-Ang1-stimulated cell cycle progression in PLFs. Tie2 knockdown also inhibited COMP-Ang1-induced phosphorylation of mitogen-activated protein kinases (MAPKs). In addition, COMP-Ang1-mediated activation of Akt and c-Jun was suppressed by treating each of pharmacological inhibitors specific to phosphoinositide 3-kinase (PI3K) (LY294002 and Wortmannin) or MAPKs (PD98059, SB203580, and SP600125). Similarly, COMP-Ang1-mediated increases in DNA synthesis and cyclin D1 induction were prevented by treating inhibitor of MAPKs and PI3K or by c-Jun knockdown. These results suggest that COMP-Ang1 enhances survival and proliferation of human PLFs through the activation of Tie2-mediated signaling, where PI3K/Akt and MAPK-c-Jun signaling pathways act as downstream effectors. Collectively, COMP-Ang1 may be a useful as a stimulator of human PLFs and therefore improves PDL integrity and homeostasis.


Assuntos
Angiopoietina-1/farmacologia , Proteína de Matriz Oligomérica de Cartilagem/farmacologia , Ciclo Celular/efeitos dos fármacos , DNA/biossíntese , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Ligamento Periodontal/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor TIE-2/metabolismo , Proteínas Recombinantes de Fusão/farmacologia , Adulto , Angiopoietina-1/genética , Proteína de Matriz Oligomérica de Cartilagem/genética , Células Cultivadas , Humanos , Masculino , Proteínas Recombinantes de Fusão/genética
8.
Mol Cell Biochem ; 419(1-2): 157-63, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27431005

RESUMO

Nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/heme oxygenase-1 (HO-1) signal is known to play important roles in controlling bone homeostasis. This study examined how oxidative stress affects the mineralization of embryonic stem (ES) cells by exposing them to glucose oxidase (GO), which continuously generates H2O2 at low concentrations. The roles of Nrf2/HO-1 and mitogen-activated protein kinases on osteogenesis in GO-exposed ES cells were also investigated. GO treatment at relatively low concentrations did not change the viability of ES cells, whereas it enhanced osteogenic differentiation and mineralization in the cells. GO treatment (1 mU/ml) augmented the induction of runt-related transcription factor 2 (Runx2), Nrf2, and HO-1 in ES cells. GO-mediated acceleration of Runx2 expression and mineralization was inhibited either by Nrf2 knockdown or by treating with 5 µM PD98059, an inhibitor of phospho-extracellular signal-regulated kinase (p-ERK). The GO-stimulated mineralization was also suppressed by treating the cells with reduced glutathione or catalase, but not by superoxide dismutase or N-acetyl-cysteine. Collectively, our results demonstrate that a mild oxidative stress activates Nrf2/HO-1 signaling and an ERK-mediated pathway, and facilitates the mineralization of ES cells with a corresponding increase in Runx2.


Assuntos
Calcificação Fisiológica/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Glucose Oxidase/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Células-Tronco Embrionárias Murinas/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Osteogênese/efeitos dos fármacos , Animais , Linhagem Celular , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Camundongos , Células-Tronco Embrionárias Murinas/citologia , Estresse Oxidativo/efeitos dos fármacos
9.
Mol Cell Biochem ; 411(1-2): 83-94, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26369531

RESUMO

Human periodontal ligament fibroblasts (hPLFs) are exposed to oxidative stress during periodontal inflammation and dental treatments. It is hypothesized that hydrogen peroxide (H2O2)-mediated oxidative stress decreases survival and osteogenic differentiation of hPLFs, whereas these decreases are prevented by activation of the Wnt pathway. However, there has been a lack of reports that define the exact roles of canonical Wnt/ß-catenin signaling in H2O2-exposed hPLFs. Treatment with H2O2 reduced viability and proliferation in hPLFs in a dose- and time-dependent manner and led to mitochondria-mediated apoptosis. Pretreatment with lithium chloride (LiCl) or Wnt1 inhibited the oxidative damage that occurred in H2O2-exposed hPLFs. However, knockout of ß-catenin or treatment with DKK1 facilitated the H2O2-induced decreases in viability, mitochondrial membrane potential, and Bcl-2 induction. Osteoblastic differentiation of hPLFs was also inhibited by combined treatment with 100 µM H2O2, as evidenced by the decreases in alkaline phosphatase (ALP) activity and mineralization. H2O2-mediated inhibition of osteoblast differentiation in hPLFs was significantly attenuated in the presence of 500 ng/ml Wnt1 or 20 mM LiCl. In particular, H2O2 stimulated the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) at protein and mRNA levels in hPLFs, whereas the induction was almost completely suppressed in the presence of Wnt1 or LiCl. Furthermore, siRNA-mediated silencing of Nrf2 blocked H2O2-induced decreases in ALP activity and mineralization of hPLFs with the concomitant restoration of runt-related transcription factor 2 and osteocalcin mRNA expression and ALP activity. Collectively, these results suggest that activation of the Wnt/ß-catenin pathway improves proliferation and mineralization in H2O2-exposed hPLFs by downregulating Nrf2.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Peróxido de Hidrogênio/farmacologia , Ligamento Periodontal/efeitos dos fármacos , Transdução de Sinais , Proteínas Wnt/metabolismo , beta Catenina/metabolismo , Adulto , Fosfatase Alcalina/metabolismo , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Humanos , Masculino , Ligamento Periodontal/citologia , Ligamento Periodontal/enzimologia , Adulto Jovem , beta Catenina/genética
10.
Mol Cell Biochem ; 402(1-2): 213-23, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25618247

RESUMO

Canonical Wnt signaling is thought to enhance osteogenic differentiation of human periodontal ligament fibroblasts (hPLFs). However, the mechanism of this enhancement has not yet been defined. We investigated the effects of Wnt1 on osteoblast differentiation of hPLFs and explored the mechanisms of the effects. Treating hPLFs with Wnt1 induced cytosolic accumulation and nuclear translocation of ß-catenin with concomitant increases in alkaline phosphatase (ALP) activity and calcium content in a time-dependent and dose-dependent manner. Wnt1-stimulated differentiation of hPLFs was accompanied by augmented phosphorylation of glycogen synthase kinase (GSK)-3ß and expression of the bone-specific factors runt-related transcription factor 2 (Runx2), osterix2 (Osx2), ALP, type I collagen, osteopontin, and osteocalcin. Pretreatment with Dickkopf-1 inhibited Wnt1-stimulated differentiation of hPLFs by suppressing GSK-3ß phosphorylation, nuclear translocation of ß-catenin, and expression of the bone-specific factors. Small interfering (si) RNA-mediated knockdown of ß-catenin, or pretreatment with FH535, markedly prevented Wnt1-stimulated differentiation of cells by blocking Runx2 and its downstream factors at the mRNA and protein levels. siRNA-mediated silencing of Runx2 also inhibited Wnt1-stimulated mineralization of cells, accompanied by a reduction in the levels of Osx2 and other early and late bone-formation regulatory factors. However, Wnt1-mediated nuclear translocation of ß-catenin and GSK-3ß phosphorylation were not inhibited by knockdown of Runx2 or FH535. Collectively, our findings suggested that Wnt1 stimulates osteogenic differentiation and mineralization of hPLFs, mainly by activating the canonical Wnt/ß-catenin pathway, in which Runx2 is a key downstream regulator.


Assuntos
Diferenciação Celular , Subunidade alfa 1 de Fator de Ligação ao Core/fisiologia , Fibroblastos/fisiologia , Osteoblastos/fisiologia , Ligamento Periodontal/citologia , Proteína Wnt1/fisiologia , Adulto , Fosfatase Alcalina/metabolismo , Calcificação Fisiológica , Células Cultivadas , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Masculino , Via de Sinalização Wnt , Adulto Jovem , beta Catenina/genética , beta Catenina/metabolismo
11.
Mol Cell Biochem ; 410(1-2): 255-66, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26346162

RESUMO

Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) regulates the induction of antioxidant gene expression and protects cells against oxidative injury. However, there are controversial findings regarding the roles of Nrf2 on bone metabolism under oxidative stress. The role of Nrf2 on the differentiation of radiation-exposed osteoblasts is also unclear. We investigated whether Nrf2 negatively or positively affects osteoblast differentiation in response to irradiation. Irradiation inhibited osteoblast differentiation of MC3T3-E1 cells in a dose-dependent manner. This inhibition was evidenced by the irradiation-mediated decreases in bone-like nodule formation, alkaline phosphatase (ALP) activity, calcium accumulation, and expression of osteoblast markers, such as ALP, osteocalcin, osteopontin, bone sialoprotein, osterix, and Runx2. These reductions were accompanied by increased induction of Nrf2 and heme oxygenase-1 (HO-1), accumulation of cellular oxidants, and depletion of antioxidant defense enzymes. siRNA-mediated silencing of Nrf2 markedly reversed the negative effect of irradiation on osteoblast differentiation of the cells, leading to a decrease in HO-1 and an increase in Runx2 levels. Irradiation-mediated decreases in the levels of Runx2 and osteocalcin mRNA, but not of Nrf2 protein, were also significantly inhibited by HO-1 inhibitor, zinc protoporphyrin IX. Furthermore, N-acetyl cysteine restored all of the changes induced by irradiation to near-normal levels in the cells. These results demonstrate that irradiation inhibits osteoblast differentiation and mineralization of MC3T3-E1 cells through the oxidative stress-mediated activation of Nrf2/HO-1 pathway.


Assuntos
Calcificação Fisiológica/efeitos da radiação , Diferenciação Celular/efeitos da radiação , Heme Oxigenase-1/biossíntese , Proteínas de Membrana/biossíntese , Fator 2 Relacionado a NF-E2/metabolismo , Osteoblastos/efeitos da radiação , Osteogênese/efeitos da radiação , Células 3T3 , Animais , Antioxidantes/farmacologia , Biomarcadores/metabolismo , Calcificação Fisiológica/efeitos dos fármacos , Cálcio/metabolismo , Diferenciação Celular/efeitos dos fármacos , Relação Dose-Resposta à Radiação , Indução Enzimática , Inibidores Enzimáticos/farmacologia , Heme Oxigenase-1/antagonistas & inibidores , Heme Oxigenase-1/genética , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/genética , Camundongos , Fator 2 Relacionado a NF-E2/genética , Osteoblastos/efeitos dos fármacos , Osteoblastos/enzimologia , Osteoblastos/patologia , Osteogênese/efeitos dos fármacos , Estresse Oxidativo/efeitos da radiação , Interferência de RNA , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos da radiação , Transfecção
12.
J Cell Biochem ; 115(11): 1877-87, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24905050

RESUMO

Because irradiation may cause osteoradionecrosis, antioxidant supplementation is often used to suppress irradiation-mediated injury. This study examined whether a synthetic phenethyl urea compound, (E)-1-(3,4-dihydroxyphenethyl)-3-(3,4-dihydroxystyryl)urea (DPDS-U), prevents irradiation-mediated cellular damage in MC3T3-E1 osteoblastic cells. A relatively high dose of irradiation (>4 Gy) decreased cell viability and proliferation and induced DNA damage and cell cycle arrest at the G(2)/M phase with the attendant increase of cyclin B1. Irradiation with 8 Gy induced intracellular reactive oxygen species (ROS) production and lipid peroxidation, and reduced glutathione content and superoxide dismutase activity in the cells. These events were significantly suppressed by treatment with 200 µM DPDS-U or 5 mM N-acetyl cysteine (NAC). DPDS-U or irradiation alone significantly increased heme oxygenase-1 (HO-1) expression and nuclear factor E2 p45-related factor-2 (Nrf2) nuclear translocation. Interestingly, pretreatment with DPDS-U facilitated irradiation-induced activation of the Nrf2/HO-1 pathway. The potential of DPDS-U to mediate HO-1 induction and protect against irradiation-mediated cellular damage was almost completely attenuated by transient transfection with Nrf2-specific siRNA or treatment with a pharmacological HO-1 inhibitor, zinc protoporphyrin IX. Additional experiments revealed that DPDS-U induced a radioprotective mechanism that differs from that induced by NAC through activation of Nrf2/HO-1 signaling. Collectively, our data suggest that DPDS-U-induced radioprotection is due to its dual function as an antioxidant to remove directly excessive intracellular ROS and as a prooxidant to stimulate intracellular redox-sensitive survival signal.


Assuntos
Acetilcisteína/farmacologia , Antioxidantes/farmacologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/efeitos da radiação , Protetores contra Radiação/farmacologia , Ureia/análogos & derivados , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos da radiação , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos da radiação , Camundongos , Osteoblastos/citologia , Espécies Reativas de Oxigênio/metabolismo , Estirenos/farmacologia , Ureia/farmacologia
13.
Biochem Biophys Res Commun ; 455(3-4): 371-7, 2014 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-25446117

RESUMO

Recombinant COMP-Ang1, a chimera of angiopoietin-1 (Ang1) and a short coiled-coil domain of cartilage oligomeric matrix protein (COMP), is under consideration as a therapeutic agent capable of inducing the homing of cells with increased angiogenesis. However, the potentials of COMP-Ang1 to stimulate migration of mesenchymal stem cells (MSCs) and the associated mechanisms are not completely understood. We examined the potential of COMP-Ang1 on bone marrow (BM)-MSCs, human periodontal ligament stem cells (PDLSCs), and calvarial osteoblasts. COMP-Ang1 augmented Tie-2 induction at protein and mRNA levels and increased proliferation and expression of runt-related transcription factor 2 (Runx2), osterix, and CXCR4 in BMMSCs, but not in osteoblasts. The COMP-Ang1-mediated increases were inhibited by Tie-2 knockdown and by treating inhibitors of phosphoinositide 3-kinase (PI3K), LY294002, or p38 mitogen-activated protein kinase (MAPK), SB203580. Phosphorylation of p38 MAPK and Akt was prevented by siRNA-mediated silencing of Tie-2. COMP-Ang1 also induced in vitro migration of BMMSCs and PDLSCs. The induced migration was suppressed by Tie-2 knockdown and by CXCR4-specific peptide antagonist or LY294002, but not by SB203580. Furthermore, COMP-Ang1 stimulated the migration of PDLSCs into calvarial defect site of rats. Collectively, our results demonstrate that COMP-Ang1-stimulated proliferation, differentiation, and migration of progenitor cells may involve the Tie-2-mediated activation of p38 MAPK and PI3K/Akt pathways.


Assuntos
Angiopoietina-1/metabolismo , Proteína de Matriz Oligomérica de Cartilagem/metabolismo , Receptor TIE-2/metabolismo , Transdução de Sinais , Adolescente , Adulto , Animais , Diferenciação Celular , Movimento Celular , Proliferação de Células , Inibidores Enzimáticos/química , Fêmur/patologia , Inativação Gênica , Humanos , Masculino , Células-Tronco Mesenquimais/citologia , Osteoblastos/citologia , Osteoblastos/metabolismo , Estrutura Terciária de Proteína , RNA Interferente Pequeno/metabolismo , Ratos , Ratos Sprague-Dawley , Tíbia/patologia , Adulto Jovem , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
14.
Stem Cells ; 31(3): 511-25, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23097336

RESUMO

Daily, cells incur tens of thousands of DNA lesions caused by endogenous processes. Due to their long-lived nature, adult stem cells may be particularly susceptible to the negative impact of this constant genotoxic stress. Indeed, in murine models of DNA repair deficiencies, there is accumulation of DNA damage in hematopoietic stem cells and premature loss of function. Herein, we demonstrate that mice expressing reduced levels of ERCC1-XPF DNA repair endonuclease (Ercc1-/Δ mice) spontaneously display a progressive decline in the number and function of hematopoietic stem/progenitor cells (HSPCs). This was accompanied by increased cell death, expression of senescence markers, reactive oxygen species, and DNA damage in HSPC populations, illustrating cell autonomous mechanisms that contribute to loss of function. In addition, the bone marrow microenvironment of Ercc1-/Δ mice was not permissive for the engraftment of transplanted normal stem cells. Bones from Ercc1-/Δ mice displayed excessive osteoclastic activity, which alters the microenvironment in a way that is unfavorable to HSPC maintenance. This was accompanied by increased proinflammatory cytokines in the bone marrow of Ercc1-/Δ mice. These data provide novel evidence that spontaneous, endogenous DNA damage, if not repaired, promotes progressive attrition of adult stem cells via both cell autonomous and nonautonomous mechanisms.


Assuntos
Reparo do DNA , Células-Tronco Hematopoéticas/fisiologia , Animais , Processos de Crescimento Celular/fisiologia , Microambiente Celular/genética , Dano ao DNA , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Endonucleases/deficiência , Endonucleases/genética , Endonucleases/metabolismo , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Mutação
15.
Front Public Health ; 12: 1302175, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38481847

RESUMO

Introduction: This study aimed to investigate the potential of short-term aerobic exercise to mitigate skeletal muscle mitochondrial damage following ambient PM2.5 exposure, and how 12 weeks of endurance training can enhance aerobic fitness to protect against such damage. Methods: Twenty-four male C57BL/6 J mice were split into sedentary (SED, n = 12) and endurance training (ETR, n = 12) groups. The ETR group underwent 12 weeks of training (10-15 m/min, 60 min/day, 4 times/week), confirmed by an Endurance Exercise Capacity (EEC) test. Post-initial training, the SED group was further divided into SSED (SED and sedentary, n = 6) and SPE (SED and PM2.5 + Exercise, n = 6). Similarly, the ETR group was divided into EEX (ETR and Exercise, n = 6) and EPE (ETR and PM2.5 + Exercise, n = 6). These groups underwent 1 week of atmospherically relevant artificial PM2.5 exposure and treadmill running (3 times/week). Following treatments, an EEC test was conducted, and mice were sacrificed for blood and skeletal muscle extraction. Blood samples were analyzed for oxidative stress indicators, while skeletal muscles were assessed for mitochondrial oxidative metabolism, antioxidant capacity, and mitochondrial damage using western blot and transmission electron microscopy (TEM). Results: After 12 weeks of endurance training, the EEC significantly increased (p < 0.000) in the ETR group compared to the SED group. Following a one-week comparison among the four groups with atmospherically relevant artificial PM2.5 exposure and exercise treatment post-endurance training, the EEX group showed improvements in EEC, oxidative metabolism, mitochondrial dynamics, and antioxidant functions. Conversely, these factors decreased in the EPE group compared to the EEX. Additionally, within the SPE group, exercise effects were evident in HK2, LDH, SOD2, and GPX4, while no impact of short-term exercise was observed in all other factors. TEM images revealed no evidence of mitochondrial damage in both the SED and EEX groups, while the majority of mitochondria were damaged in the SPE group. The EPE group also exhibited damaged mitochondria, although significantly less than the SPE group. Conclusion: Atmospherically relevant artificial PM2.5 exposure can elevate oxidative stress, potentially disrupting the benefits of short-term endurance exercise and leading to mitochondrial damage. Nonetheless, increased aerobic fitness through endurance training can mitigate PM2.5-induced mitochondrial damage.


Assuntos
Treino Aeróbico , Condicionamento Físico Animal , Humanos , Masculino , Camundongos , Animais , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Condicionamento Físico Animal/métodos , Condicionamento Físico Animal/fisiologia , Resistência Física/fisiologia , Camundongos Endogâmicos C57BL , Mitocôndrias , Mitocôndrias Musculares/metabolismo , Músculo Esquelético/metabolismo , Material Particulado/efeitos adversos
16.
Exp Mol Med ; 56(1): 118-128, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38200155

RESUMO

The harmful effects of fine particulate matter ≤2.5 µm in size (PM2.5) on human health have received considerable attention. However, while the impact of PM2.5 on the respiratory and cardiovascular systems has been well studied, less is known about the effects on stem cells in the bone marrow (BM). With an emphasis on the invasive characteristics of PM2.5, this review examines the current knowledge of the health effects of PM2.5 exposure on BM-residing stem cells. Recent studies have shown that PM2.5 enters the circulation and then travels to distant organs, including the BM, to induce oxidative stress, systemic inflammation and epigenetic changes, resulting in the reduction of BM-residing stem cell survival and function. Understanding the broader health effects of air pollution thus requires an understanding of the invasive characteristics of PM2.5 and its direct influence on stem cells in the BM. As noted in this review, further studies are needed to elucidate the underlying processes by which PM2.5 disturbs the BM microenvironment and inhibits stem cell functionality. Strategies to prevent or ameliorate the negative effects of PM2.5 exposure on BM-residing stem cells and to maintain the regenerative capacity of those cells must also be investigated. By focusing on the complex relationship between PM2.5 and BM-resident stem cells, this review highlights the importance of specific measures directed at safeguarding human health in the face of rising air pollution.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Células-Tronco Mesenquimais , Humanos , Material Particulado/efeitos adversos , Poluentes Atmosféricos/efeitos adversos , Medula Óssea , Poluição do Ar/efeitos adversos , Exposição Ambiental
17.
Aging Dis ; 15(2): 755-766, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37548936

RESUMO

One of the most important strategies for successful aging is exercise. However, the effect of exercise can differ among individuals, even with exercise of the same type and intensity. Therefore, this study aims to confirm whether endurance training (ETR) has the same health-promoting effects on the musculoskeletal and hematopoietic systems regardless of age. Ten weeks of ETR improved endurance exercise capacity, with increased skeletal muscle mitochondrial enzymes in both young and old mice. In addition, age-related deterioration of muscle fiber size and bone microstructure was improved. The expression levels of myostatin, muscle RING-finger protein-1, and muscle atrophy F-box in skeletal muscle and peroxisome proliferator-activated receptor-γ in the femur increased with age but decreased after ETR. ETR differentially modulated hematopoietic stem cells (HSCs) depending on age; ETR induced HSC quiescence in young mice but caused HSC senescence in old mice. ETR has differential effects on modulation of the musculoskeletal and hematopoietic systems in old mice. In other words, endurance exercise is a double-edged sword for successful aging, and great effort is required to establish exercise strategies for healthy aging.


Assuntos
Músculo Esquelético , Fatores de Transcrição , Camundongos , Animais , Fatores de Transcrição/metabolismo , Músculo Esquelético/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Mitocôndrias/metabolismo , Envelhecimento/fisiologia
18.
Mol Cell Biochem ; 382(1-2): 37-45, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24026476

RESUMO

Fibroblast growth factor-7 (FGF7) is known to regulate proliferation and differentiation of cells; however, little information is available on how FGF7 affects the differentiation of embryonic stem cells (ESCs). We examined the effects of FGF7 on proliferation and osteogenic differentiation of mouse ESCs. Exogenous FGF7 addition did not change the proliferation rate of mouse ESCs. In contrast, the addition of FGF7 facilitated the dexamethasone, ascorbic acid, and ß-glycerophosphate (DAG)-induced increases in bone-like nodule formation and calcium accumulation. FGF7 also augmented mRNA expression of runt-related transcription factor-2 (Runx2), osterix, bone sialoprotein (BSP), and osteocalcin (OC) in the presence of DAG. FGF7-mediated increases in the mineralization and bone-specific gene expression were almost completely attenuated by pretreating with anti-FGF7 antibody. FGF7 treatment accelerated the DAG-induced activation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) in the cells. A pharmacological inhibitor specific to ERK, but not to JNK or p38 kinase, dramatically suppressed FGF7-mediated mineralization and accumulation of collagen and OC in the presence of DAG. This suppression was accompanied by the reduction in Runx2, osterix, BSP, and OC mRNA levels, which were increased by FGF7 in the presence of DAG. Collectively, our results suggest that FGF7 stimulates osteogenic differentiation, but not proliferation, in ESCs, by activating ERK/Runx2 signaling.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fator 7 de Crescimento de Fibroblastos/farmacologia , Osteogênese/efeitos dos fármacos , Fosfatase Alcalina/metabolismo , Animais , Biomarcadores/metabolismo , Calcificação Fisiológica/efeitos dos fármacos , Calcificação Fisiológica/genética , Diferenciação Celular/genética , Linhagem Celular , Células-Tronco Embrionárias/efeitos dos fármacos , Células-Tronco Embrionárias/enzimologia , Regulação da Expressão Gênica/efeitos dos fármacos , Glicerofosfatos/farmacologia , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Camundongos , Especificidade de Órgãos/efeitos dos fármacos , Especificidade de Órgãos/genética , Osteogênese/genética , Inibidores de Proteínas Quinases/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
19.
Cells ; 12(19)2023 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-37830627

RESUMO

Prion diseases are neurodegenerative disorders that are progressive, incurable, and deadly. The prion consists of PrPSc, the misfolded pathogenic isoform of the cellular prion protein (PrPC). PrPC is involved in a variety of physiological functions, including cellular proliferation, adhesion, differentiation, and neural development. Prion protein is expressed on the membrane surface of a variety of stem cells (SCs), where it plays an important role in the pluripotency and self-renewal matrix, as well as in SC differentiation. SCs have been found to multiply the pathogenic form of the prion protein, implying their potential as an in vitro model for prion diseases. Furthermore, due to their capability to self-renew, differentiate, immunomodulate, and regenerate tissue, SCs are prospective cell treatments in many neurodegenerative conditions, including prion diseases. Regenerative medicine has become a new revolution in disease treatment in recent years, particularly with the introduction of SC therapy. Here, we review the data demonstrating prion diseases' biology and molecular mechanism. SC biology, therapeutic potential, and its role in understanding prion disease mechanisms are highlighted. Moreover, we summarize preclinical studies that use SCs in prion diseases.


Assuntos
Doenças Neurodegenerativas , Doenças Priônicas , Príons , Humanos , Proteínas Priônicas , Doenças Priônicas/metabolismo , Príons/metabolismo , Células-Tronco/metabolismo
20.
J Hazard Mater ; 452: 131293, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37002998

RESUMO

Research on the negative impacts of PM2.5 have been focused on lung, brain, immune, and metabolism-related diseases. However, little is known about the mechanism underlying the effects of PM2.5 on the modulation of hematopoietic stem cell (HSC) fate. Maturation of the hematopoietic system and differentiation of hematopoietic stem progenitor cells (HSPCs) occurs soon after birth when infants are susceptible to external stresses. We investigated how exposure to atmospherically relevant artificial particulate matter of diameter < 2.5 µm (termed, PM2.5) affects HSPCs in newborns. The lungs of newborn mice exposed to PM2.5 exhibited higher levels of oxidative stress and inflammasome activation, which continued during aging. PM2.5 also stimulated oxidative stress and inflammasome activation in bone marrow (BM). PM2.5-exposed infant mice at 12 months but not at 6 months displayed progressive senescence of HSCs accompanied by preferential impairment of the BM microenvironment with age-related phenotypes, as evidenced by colony-forming assay and serial transplantation and animal survival experiments. Further, PM2.5-exposed middle-aged mice did not exhibit radioprotective potential. Collectively, exposure of newborns to PM2.5 causes progressive senescence of HSCs. These findings revealed a novel mechanism by which PM2.5 affects the fate of HSCs, highlighting the crucial role of early life exposure to air pollution in determining human health outcomes.


Assuntos
Inflamassomos , Material Particulado , Humanos , Camundongos , Animais , Material Particulado/toxicidade , Células-Tronco Hematopoéticas , Estresse Oxidativo , Diferenciação Celular
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