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1.
Aging Cell ; 18(6): e13024, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31389140

RESUMO

Prolonging the ovarian lifespan is attractive and challenging. An optimal clinical strategy must be safe, long-acting, simple, and economical. Allotransplantation of brown adipose tissue (BAT), which is most abundant and robust in infants, has been utilized to treat various mouse models of human disease. Could we use BAT to prolong the ovarian lifespan of aging mice? Could we try BAT xenotransplantation to alleviate the clinical need for allogeneic BAT due to the lack of voluntary infant donors? In the current study, we found that a single rat-to-mouse (RTM) BAT xenotransplantation did not cause systemic immune rejection but did significantly increase the fertility of mice and was effective for more than 5 months (equivalent to 10 years in humans). Next, we did a series of analysis including follicle counting; AMH level; estrous cycle; mTOR activity; GDF9, BMP15, LHR, Sirt1, and Cyp19a level; ROS and annexin V level; IL6 and adiponectin level; biochemical blood indices; body temperature; transcriptome; and DNA methylation studies. From these, we proposed that rat BAT xenotransplantation rescued multiple indices indicative of follicle and oocyte quality; rat BAT also improved the metabolism and general health of the aging mice; and transcriptional and epigenetic (DNA methylation) improvement in F0 mice could benefit F1 mice; and multiple KEGG pathways and GO classified biological processes the differentially expressed genes (DEGs) or differentially methylated regions (DMRs) involved were identical between F0 and F1. This study could be a helpful reference for clinical BAT xenotransplantation from close human relatives to the woman.

2.
Mater Sci Eng C Mater Biol Appl ; 99: 1021-1034, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30889634

RESUMO

In order to develop a biodegradable guided bone regeneration membrane with the required mechanical properties and high corrosion resistance, Zn-0.8%Li(wt), Zn-0.8%Li-0.2%Mg(wt), and Zn-0.8%Li-0.2%Ag(wt) alloys were cast and hot rolled into 0.1-mm thick sheets. The main secondary phase in Zn-0.8%Li-(Mg, Ag) alloys was the LiZn4 nanoprecipitate. Following the addition of minimal amounts of Mg, the tensile strength of the Zn-0.8%Li-0.2%Mg alloy improved, albeit with a greatly reduced elongation and corrosion resistance. The addition of minimal amounts of Ag refined the microstructure, producing fine equiaxed grains (2.3 µm) in the Zn-0.8%Li-0.2%Ag alloy, and promoted a uniform distribution of LiZn4 nanoprecipitates with increased density and refined size. Therefore, the Zn-0.8%Li-0.2%Ag alloy exhibited optimal tensile strength and the highest corrosion resistance, with its elongation reaching 97.9 ±â€¯8.7%. The corrosion products of Zn-0.8%Li-(Mg, Ag) alloys immersed in Ringer's solution for 35 days mainly consisted of zinc oxide and zinc carbonate. In addition, the cytotoxicity test using L929 cells and the evaluation of bone marrow mesenchymal stem cell proliferation indicated that the Zn-0.8%Li-0.2%Ag alloy had good biocompatibility.


Assuntos
Ligas/farmacologia , Materiais Biocompatíveis/farmacologia , Regeneração Óssea/efeitos dos fármacos , Regeneração Tecidual Guiada , Lítio/farmacologia , Fenômenos Mecânicos , Prata/farmacologia , Zinco/farmacologia , Animais , Morte Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Corrosão , Técnicas Eletroquímicas , Concentração de Íons de Hidrogênio , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Camundongos , Espectroscopia de Infravermelho com Transformada de Fourier , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração , Difração de Raios X
3.
Aging (Albany NY) ; 11(4): 1110-1128, 2019 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-30786262

RESUMO

Tight control of energy metabolism is essential for normal cell function and organism survival. PKM (pyruvate kinase, muscle) isoforms 1 and 2 originate from alternative splicing of PKM pre-mRNA. They are key enzymes in oxidative phosphorylation and aerobic glycolysis, respectively, and are essential for ATP generation. The PKM1:PKM2 expression ratio changes with development and differentiation, and may also vary under metabolic stress and other conditions. Until now, there have been no reports about the function and regulation of PKM isozymes in oocytes. Here, we demonstrate that PKM1 or PKM2 depletion significantly disrupts ATP levels and mitochondrial integrity, and exacerbates free-radical generation and apoptosis in mouse oocytes. We also show that KBTBD8, a female fertility factor in the KBTBD ubiquitin ligase family, selectively regulates PKM1 levels through a signaling cascade that includes Erk1/2 and Aurora A kinases as intermediates. Finally, using RNA sequencing and protein network analysis, we identify several regulatory proteins that may be govern generation of mature PKM1 mRNA. These results suggest KBTBD8 affects PKM1 levels in oocytes via a KBTBD8→Erk1/2→Aurora A axis, and may also affect other essential processes involved in maintaining oocyte quality.

4.
ACS Appl Mater Interfaces ; 10(44): 38032-38041, 2018 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-30360054

RESUMO

The development of an efficient, robust, and low-cost catalyst for water electrolysis is critically important for renewable energy conversion. Herein, we achieve a significant improvement in electrocatalytic activity for both the oxygen-evolution reaction (OER) and the hydrogen-evolution reaction (HER) by constructing a novel hierarchical PrBa0.5Sr0.5Co2O5+δ (PBSC)@FeOOH catalyst. The optimized PBSC@FeOOH-20 catalyst consisted of layered perovskite PBSC nanorods and 20 nm thick amorphous FeOOH nanoflakes exhibiting an excellent electrocatalytic activity for the OER and the HER in 0.1 M KOH media, delivering a current density of 10 mA cm-2 at overpotentials of 390 mV for the OER and 280 mV for the HER, respectively. The substantially enhanced performance is probably attributed to the hierarchical nanostructure, the good charge-transfer capability, and the strong electronic interactions of FeOOH and PBSC. Importantly, an alkaline electrolyzer-integrated PBSC@FeOOH-20 catalyst as both the anode and cathode shows a highly active overall water splitting with a low voltage of 1.638 V at 10 mA cm-2 and high stability during continuous operation. This study provides new insights into exploring efficient bifunctional catalysts for overall water splitting, and it suggests that the rational design of the oxyhydroxide/perovskite heterostructure shows great potential as a promising type of electrocatalysts.

5.
FASEB J ; 32(10): 5483-5494, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29723063

RESUMO

Placenta-specific 1 (Plac1) has been found to be essential for placentation, and abnormal Plac1 expression and distribution is highly correlated with preeclampsia and implantation failure; however, its function in mammalian oocytes has not been elucidated. Here, we report that Plac1 was more prominent in mouse oocytes and enriched at the membrane region throughout meiosis. On the one hand, Plac1 knockdown severely disrupted microvillus organization; however, on the other hand, Plac1 significantly decreased oocyte maturation and increased aneuploidy, consequently disrupting normal fertilization. On the basis of immunoprecipitate matrix-assisted laser desorption/ionization, we established a working model, then verified and suggested that, at the germinal vesicle stage, Plac1 enriches the membrane to activate furin, and active furin subsequently activates IGF-1 receptor to maintain regular microvillus organization. Upon meiosis onset, active furin/IGF-1 receptor relocates into the cytoplasm to activate (phosphorylate) Akt to promote meiosis. In summary, our finding suggests that Plac1, a protein that is crucial for placentation, is also essential for oocyte meiosis and fertilization.-Shi, L.-Y., Ma, Y., Zhu, G.-Y., Liu, J.-W., Zhou, C.-X., Chen, L.-J., Wang, Y., Li, R.-C., Yang, Z.-X., Zhang, D. Placenta-specific 1 regulates oocyte meiosis and fertilization through furin.


Assuntos
Fertilização/fisiologia , Furina/metabolismo , Meiose/fisiologia , Oócitos/metabolismo , Proteínas da Gravidez/metabolismo , Animais , Ativação Enzimática/fisiologia , Feminino , Furina/genética , Camundongos , Camundongos Endogâmicos ICR , Oócitos/citologia , Proteínas da Gravidez/genética , Transporte Proteico/fisiologia , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor IGF Tipo 1/genética , Receptor IGF Tipo 1/metabolismo
6.
Artigo em Inglês | MEDLINE | ID: mdl-26916052

RESUMO

Design of prosthetic implants to ensure rapid and stable osseointegration remains a significant challenge, and continuous efforts have been directed to new implant materials, structures and morphology. This paper aims to develop and characterise a porous titanium dental implant fabricated by metallic powder injection-moulding. The surface morphology of the specimens was first examined with a scanning electron microscope (SEM), followed by microscopic computerised tomography (µ-CT) scanning to capture its 3D microscopic features non-destructively. The nature of porosity and pore sizes were determined statistically. A homogenisation technique based on the Hills-energy theorem was adopted to evaluate its directional elastic moduli, and the conservation of mass theorem was employed to quantify the oxygen diffusivity for bio-transportation feature. This porous medium was found to have pore sizes varying from 50 to 400 µm and the average porosity of 46.90 ± 1.83%. The anisotropic principal elastic moduli were found fairly close to the upper range of cortical bone, and the directional diffusivities could potentially enable radial osseous tissue ingrowth and vascularisation. This porous titanium successfully reduces the elastic modulus mismatch between implant and bone for dental and orthopaedic applications, and provides improved capacity for transporting oxygen, nutrient and waste for pre-vascular network formation. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Implantes Dentários , Titânio , Microtomografia por Raio-X/métodos , Difusão , Módulo de Elasticidade , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Osseointegração , Oxigênio/metabolismo , Porosidade , Propriedades de Superfície
7.
Mater Sci Eng C Mater Biol Appl ; 61: 8-14, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26838817

RESUMO

Osteoblasts growing into bone substitute is an important step of bone regeneration. This study prepared porous hydroxyapatite (HA)/BaTiO3 piezoelectric composites with porosity of 40%, 50% and 60% by ice-templating method. Effects of HA/BaTiO3 composites with different porosities, with and without polarizing treatment on adhesion, proliferation and differentiation of osteoblasts were investigated in vitro. Results revealed that cell densities of the porous groups were significantly higher than those of the dense group (p<0.05), so did the alkaline phosphate (ALP) and bone gla protein (BGP) activities. Porosity of 50% group exhibited higher ALP activity and BGP activity than those of the 40% and 60% groups. Scanning electron microscopy (SEM) observations revealed that osteoblasts adhered and stretched better on porous HA/BaTiO3 than on the dense one, especially HA/BaTiO3 with porosity of 50% and 60%. However, there was no significant difference in the cell morphology, cell densities, ALP and BGP activities between the polarized group and the non-polarized group (p>0.05). The absence of mechanical loading on the polarized samples may account for this. The results indicated that hierarchically porous HA/BaTiO3 played a favorable part in osteoblasts proliferation, differentiation and adhesion process and is a promising bone substitute material.


Assuntos
Compostos de Bário , Materiais Biomiméticos , Substitutos Ósseos , Durapatita , Osteoblastos/metabolismo , Compostos de Bário/química , Compostos de Bário/farmacologia , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Substitutos Ósseos/química , Substitutos Ósseos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Durapatita/química , Durapatita/farmacologia , Humanos , Osteoblastos/citologia
8.
Biointerphases ; 9(3): 031004, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25280845

RESUMO

A Mg-Zn-tricalcium phosphate composite with a chitosan coating was prepared in this investigation to study its biodegradation performance both in vitro and in vivo conditions. The in vitro test results show that the immersion corrosion rate, the pH values of the simulated body fluids and the released metal ion concentration of the chitosan coated composite are all lower than those of the uncoated composite. The in vitro cytotoxicity test shows that the chitosan coated specimens is safe for cellular applications. When the chitosan coated composite is tested in vivo, the concentration of metal ions from the composite observed in the venous blood of Zelanian rabbits is less than the uncoated composite specimens. The chitosan coating slows down the in vivo degradation of the composite after surgery. In vivo testing also indicates that the chitosan coated composite is harmless to important visceral organs, including the heart, kidneys, and liver of the rabbits. The new bone formation surrounding the chitosan coated composite implant shows that the composite improves the concrescence of the bone tissues. The chitosan coating is an effective corrosion resistant layer that reduces the hydrogen release of the implant composite, thereby decreasing the subcutaneous gas bubbles formed.


Assuntos
Biotransformação , Fosfatos de Cálcio/metabolismo , Quitosana/metabolismo , Materiais Revestidos Biocompatíveis/metabolismo , Magnésio/metabolismo , Próteses e Implantes/efeitos adversos , Zinco/metabolismo , Animais , Líquidos Corporais/química , Líquidos Corporais/metabolismo , Fosfatos de Cálcio/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Quitosana/toxicidade , Materiais Revestidos Biocompatíveis/efeitos adversos , Corrosão , Concentração de Íons de Hidrogênio , Magnésio/toxicidade , Camundongos , Coelhos , Zinco/toxicidade
9.
Mater Sci Eng C Mater Biol Appl ; 39: 143-9, 2014 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-24863210

RESUMO

It was proposed that the piezoelectric effect played an important physiological role in bone growth, remodelling and fracture healing. An aligned porous piezoelectric composite scaffold was fabricated by freeze casting hydroxyapatite/barium titanate (HA/BT) suspensions. The highest compressive strength and lowest porosity of 14.5MPa and 57.4% with the best parallelism of the pore channels were achieved in the HA10/BT90 composite. HA30/BT70 and HA10/BT90 composites exhibited piezoelectric coefficient d33 of 1.2 and 2.8pC/N, respectively, both of which were higher than the piezoelectric coefficient of natural bone. Increase of the solid loading of the suspension and solidification velocity led to the improvement of piezoelectric coefficient d33. Meanwhile, double-templates resulted in the coexistence of lamellar pores and aligned macro-pores, exhibiting the ability to produce an oriented long-range ordered architecture. The manipulation flexibility of this method indicated the potential for customized needs in the application of bone substitute. An MTT assay indicated that the obtained scaffolds had no cytotoxic effects on L929 cells.


Assuntos
Compostos de Bário/química , Osso e Ossos/química , Hidroxiapatitas/química , Engenharia Tecidual/métodos , Animais , Materiais Biocompatíveis/química , Substitutos Ósseos/química , Linhagem Celular , Força Compressiva , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Teste de Materiais , Camundongos , Microscopia Eletrônica de Varredura , Porosidade , Tecidos Suporte/química , Difração de Raios X
10.
Acta Biomater ; 8(7): 2845-55, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22503951

RESUMO

In this study 5, 10 and 15% ß-Ca(3)(PO(4))(2)/Mg-Zn composites were prepared through powder metallurgy methods, and their corrosion behavior and mechanical properties were studied in simulated body fluid (SBF) at 37°C. The 10% ß-Ca(3)(PO(4))(2)/Mg-Zn composite was selected for cytocompatibility assessment and in vivo biodegradation testing. The results identified the α-Mg, MgZn and ß-Ca(3)(PO(4))(2) phases in these sintered composites. The density and elastic modulus of the ß-Ca(3)(PO(4))(2)/Mg-6% Zn composite match those of natural bone, and the strength is approximately double that of natural bone. The 10% ß-Ca(3)(PO(4))(2)/Mg-6% Zn composites exhibit good corrosion resistance, as determined by a 30 day immersion test and electrochemical measurements in SBF at 37°C. The 10% ß-Ca(3)(PO(4))(2)/Mg-6% Zn composite is safe for cellular applications, with a cytotoxicity grade of ∼0-1 against L929 cells in in vitro testing. The ß-Ca(3)(PO(4))(2)/Mg-6% Zn composite also exhibits good biocompatibility with the tissue and the important visceral organs the heart, kidney and liver of experimental rabbits. The composite has a suitable degradation rate and improves the concrescence of a pre-broken bone. The corrosion products, such as Mg(OH)(2) and Ca(5)(PO(4))(6)(OH)(2), can improve the biocompatibility of the ß-Ca(3)(PO(4))(2)/Mg-Zn composite.


Assuntos
Materiais Biocompatíveis/farmacologia , Fosfatos de Cálcio/farmacologia , Magnésio/farmacologia , Teste de Materiais/métodos , Tecidos Suporte/química , Zinco/farmacologia , Animais , Líquidos Corporais/efeitos dos fármacos , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/cirurgia , Linhagem Celular , Corrosão , Hidrogênio/análise , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Magnésio/sangue , Masculino , Fenômenos Mecânicos/efeitos dos fármacos , Especificidade de Órgãos/efeitos dos fármacos , Implantação de Prótese , Coelhos , Microtomografia por Raio-X , Zinco/sangue
11.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 35(7): 662-72, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20693706

RESUMO

OBJECTIVE: To investigate the stress distributions on implant-bone interface and fatigue behaviors of biomimetic titanium implant under static and dynamic loading conditions to provide theoretical basis for a new implant which may effectively transfer the stress to surrounding bones. METHODS: A 3-D finite element model of a posterior mandible segment with an implant bone was constructed by a CAD (Pro/E Widefire 2.0) software. Two different implant models (a dense implant No.1 and a biomimetic implant No.2) were designed. The stress distributions on bone-implant interface under dynamic and static loading conditions were analyzed by Ansys Workbench 10.0 software, as well as the fatigue behavior of the biomimetic implant. RESULTS: The cervical cortical bones in the 2 implants were all high stress region under the same loading condition. The maximum von Mises stress on the interface and high-stress region in the cancellous bone region, and the maximum stress in the root region of the biomimetic implant were lower than those of the dense implant. The stress on the implant-bone interface decreased from the top to the bottom. The stress in the cervical cortical bone under the dynamic loading was 17.15% higher than that of the static loading. There was no significant difference in maximum stress at the cortical bone region between the dynamic and static loading conditions. The maximum stress of the dense implant in the cancellous bone region was 75.97% higher and that in the root region was 22.46% higher than that of the biomimetic implant. The maximum stress on the implant-bone interface was far less than the yield strength of pure titanium. The stress distribution in the cortical region of the biomimetic implant was 7.85% higher than that of the dense implant, and the maximum stress in the cortical bone was smaller than the yield stress of cortical bone. Within the dynamic loading of 50-300 N, the safety coefficient was all higher than 10, and with the increase of loading pressure, interface stress in the cancellous region increased linearly. Under the loading of 300 N in the axial and 25 N in the lingual 45:, the maximum stress was 11.38 MPa. CONCLUSION: Biomimetic style implant can effectively transfer the implant-bone interface stress to surrounding bones in the cancellous bone and root region, and the structure with the improved design is safe under normal loading pressure.


Assuntos
Materiais Biomiméticos , Implantes Dentários , Análise do Estresse Dentário , Análise de Elementos Finitos , Mandíbula/fisiologia , Titânio , Materiais Biocompatíveis , Fenômenos Biomecânicos , Materiais Biomiméticos/química , Simulação por Computador , Desenho Assistido por Computador , Humanos , Modelos Biológicos , Próteses e Implantes , Estresse Mecânico , Propriedades de Superfície , Titânio/química
12.
Hunan Yi Ke Da Xue Xue Bao ; 28(4): 385-7, 2003 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-14653124

RESUMO

OBJECTIVE: To investigate the effect of cast post-core porcelain fused to metal crown on the restoration of residual root and crown of molars. METHODS: One hundred and sixty-four residual roots and crowns of molars were treated with root canal therapy and restored by cast core porcelain fused to metal crown. The restoration effect was assessed at the 3rd, 6th, 12th and 24th month. RESULTS: The strength of dental prosthesis retention, marginal fitness, and strength of crowns were satisfactory. The effective rate reached 95.12% during the 2 year follow-up. CONCLUSION: The cast post-core porcelain fused to metal crown is a better method in treating the residual root and crown of molars.


Assuntos
Coroas , Ligas Metalo-Cerâmicas , Preparo Prostodôntico do Dente , Adulto , Retenção em Prótese Dentária , Restauração Dentária Permanente , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dente Molar , Preparo Prostodôntico do Dente/métodos , Raiz Dentária
13.
Hunan Yi Ke Da Xue Xue Bao ; 27(3): 282-4, 2002 Jun 28.
Artigo em Chinês | MEDLINE | ID: mdl-12575319

RESUMO

OBJECTIVE: To investigate telomerase activity in human salivary cancer and corresponding adjacent tissues and to explore the possibility of telomerase as a tumor marker and its clinical significance. METHODS: Twenty-eight salivary cancers, 28 adjacent peritumoral tissues, 10 mixed tumors, 6 adenolymphomas, and 5 normal salivary tissues were examined for telomerase activity by the silver-staining TRAP assay based on PCR. RESULTS: Twenty-five of the 28 salivary cancers and 2 of the 28 adjacent peritumoral tissue specimens were positive for telomerase activity with a positive rate of 89.3% and 6.3%, respectively. Telomerase activity was negative in the 10 mixed tumors, 6 adenolymphomas, and 5 normal salivary tissues. There was no correlation between the clinical stage of salivary cancer and its expression of telomerase activity (P > 0.05). CONCLUSION: Positive telomerase activity occurs in the majority of salivary cancers examined. It can be used as a tumor marker in the diagnosis of salivary cancer. Detection of telomerase activity in the adjacent peritumoral tissues can be used as a monitoring marker after treatment.


Assuntos
Adenoma Pleomorfo/enzimologia , Neoplasias das Glândulas Salivares/enzimologia , Telomerase/metabolismo , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/enzimologia , Humanos
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