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1.
Nanoscale ; 11(43): 20884-20892, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31660556

RESUMO

In elderly people particularly in postmenopausal women, inadequate bone formation by osteoblasts originating from bone marrow mesenchymal stem cells (BMSCs) for compensation of bone resorption by osteoclasts is a major reason for osteoporosis. Enhancing osteoblastic differentiation of BMSCs is a feasible therapeutic strategy for osteoporosis. Here, bone marrow stromal cell (ST)-derived exosomes (STExos) are found to remarkably enhance osteoblastic differentiation of BMSCs in vitro. However, intravenous injection of STExos is inefficient in ameliorating osteoporotic phenotypes in an ovariectomy (OVX)-induced postmenopausal osteoporosis mouse model, which may be because STExos are predominantly accumulated in the liver and lungs, but not in bone. Hereby, the STExo surface is conjugated with a BMSC-specific aptamer, which delivers STExos into BMSCs within bone marrow. Intravenous injection of the STExo-Aptamer complex enhances bone mass in OVX mice and accelerates bone healing in a femur fracture mouse model. These results demonstrate the efficiency of BMSC-specific aptamer-functionalized STExos in targeting bone to promote bone regeneration, providing a novel promising approach for the treatment of osteoporosis and fracture.

2.
Math Biosci Eng ; 16(5): 4122-4134, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31499654

RESUMO

In this study, NaNbO3 with average grain size of ~50 nm and KNbO3 with average grain size of ~300 nm nanocrystals are prepared by the water-based citrate precursor sol-gel process. However, the KNbO3 sample exhibits better photocatalytic performance than that of the NaNbO3 sample by Rh B degradation experiment. By Rietveld refinements and piezoelectric displacement measurements, the KNbO3 with the space group of Bmm2 is ferroelectric while the NaNbO3 with the space group of Pbma is antiferroelectric. The polarization-modulated built-in electric fields in the ferroelectric KNbO3 nanoparticles can efficiently enhance the separation of photo-generated charge carries and thus improve the photocatalytic activity. However, there is no internal electric field in the antiferroelectric grain because of the antiparallel spontaneous polarization in the adjacent unit cell. Therefore, KNbO3 exhibits better oxidizing ability of organic dyes than NaNbO3. The ferroelectric KNbO3 nanoparticles exhibit an optimum photocatalytic performance for a complete degradation of Rh B in 100 min under UV-Vis light irradiation with auxiliary ultrasonic excitation. This study demonstrates that the perovskite-type ferroelectric nanocrystals are potentially to design high-performance catalysts for degradation of contaminant.

3.
Zhongguo Zhong Yao Za Zhi ; 44(13): 2753-2761, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31359687

RESUMO

Chlorophyll content,leaf mass to per area,net photosynthetic rate and bioactive ingredients of Asarum heterotropoides var. mandshuricum,a skiophyte grown in four levels of solar irradiance were measured and analyzed in order to investigate the response of photosynthetic capability to light irradiance and other environmental factors. It suggested that the leaf mass to per area of plant was greatest value of four kinds of light irradiance and decreasing intensity of solar irradiance resulted in the decrease of leaf mass to per area at every phenological stage. At expanding leaf stage,the rate of Chla and Chlb was 3. 11 when A. heterotropoides var. mandshuricum grew in full light irradiance which is similar to the rate of heliophytes,however,the rate of Chla and Chlb was below to 3. 0 when they grew in shading environment. The content of Chla,Chlb and Chl( a+b) was the greatest value of four kinds of light irradiance and decreasing intensity of solar irradiance resulted in its decreasing remarkably( P<0. 05). The rate of Chla and Chlb decreased but the content of Chla,Chlb and Chl( a+b) increased gradually with continued shading. The maximum value of photosynthetically active radiation appeared at 10: 00-12: 00 am in a day. The maximum value of net photosynthetic rate appeared at 8: 30-9: 00 am and the minimum value appeared at 14: 00-14: 30 pm at each phenological stage if plants grew in full sunlight. However,when plants grew in shading,the maximum value of net photosynthetic rate appeared at about 10: 30 am and the minimum value appeared at 12: 20-12: 50 pm at each phenological stage. At expanding leaf stage and flowering stage,the average of net photosynthetic rate of leaves in full sunlight was remarkably higher than those in shading and it decreased greatly with decreasing of irradiance gradually( P < 0. 05). However,at fruiting stage,the average of net photosynthetic rate of leaves in full sunlight was lower than those in 50% and 28% full sunlight but higher than those in 12% full sunlight. All photosynthetic diurnal variation parameters of plants measured in four kinds of different irradiance at three stages were used in correlation analysis. The results suggested that no significant correlation was observed between net photosynthetic rate and photosynthetically active radiation,and significant negative correlation was observed between net photosynthetic rate and environmental temperature as well as vapor pressure deficit expect for 12% full sunlight. Positive correlation was observed between net photosynthestic rate and relative humidity expect for 12% full sunlight. Significant positive correlation was observed between net photosynthetic rate and stomatal conductance in the four light treatments. Only,in 12% full sunlight,the net photosynthetic rate was significantly related to photosynthetically active radiation rather than related to environmental temperature,vapor pressure deficit and relative humidity. In each light treatment,a significant positive correlation was observed between environmental temperature and vapor pressure deficit,relative humidity as well as stomatal conductance. Volatile oil content was 1. 46%,2. 16%,1. 56%,1. 30% respectively. ethanol extracts was 23. 44%,22. 45%,22. 18%,21. 12% respectively. Asarinin content was 0. 281%,0. 291%,0. 279% and 0. 252% respectively. The characteristic components of Asarum volatile oil of plant in different light treatments did not change significantly among different groups.


Assuntos
Asarum/fisiologia , Asarum/efeitos da radiação , Fotossíntese , Luz Solar , Clorofila/análise , Folhas de Planta/efeitos da radiação
4.
J Nanosci Nanotechnol ; 19(12): 7967-7973, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31196317

RESUMO

Using a mixed self-assembly method, this research utilized modified Mb-functionalized gold nanoparticles (Mb-AuNPs-MPA) on the gold electrode surface to prepare a biosensor which was applied to detect superoxide anion-free electron mediators. Together with the study on the performance of the sensor, the characteristics of modified nanoclusters were investigated by UV-Vis and FTIR and the electrochemical characteristics of the electrode surface were investigated using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), respectively. It was demonstrated that the charge transfer resistance (Rct) of the modified electrode (Mb-MPA-AuNPs/Au) was 7862 Ω, the exchange current density (i0) was 32.7 µA/cm-2. And a pair of reversible and symmetrical redox peaks appeared after the coordination of Cu2+, and the electrical signal response of Cu2+/Mb-AuNPs-MPA/Au reached the highest. The superoxide anion generated in the basic DMSO system was determined by CV using the modified electrode Cu2+/Mb-AuNPs-MPA/Au. It was discovered that the superoxide anion had a strong disproportionation effect.

5.
Theranostics ; 9(9): 2678-2693, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31131061

RESUMO

Poor wound healing affects millions of people worldwide each year and needs better therapeutic strategies. Synechococcus elongatus PCC 7942 is a naturally occurring photoautotrophic cyanobacterium that can be easily obtained and large-scale expanded. Here, we investigated the therapeutic efficacy of this cyanobacterium in a mouse model of acute burn injury and whether the secretion of extracellular vesicles (EVs), important mediators of cell paracrine activity, is a key mechanism of the cyanobacterium-induced regulation of wound healing. Methods: The effects of Synechococcus elongatus PCC 7942 on burn wound healing in mice under light or dark conditions were evaluated by measuring wound closure rates, histological and immunofluorescence analyses. A series of assays in vivo and in vitro were conducted to assess the impact of the cyanobacterium on angiogenesis. GW4869 was used to interfere with the secretion of EVs by the cyanobacterium and the abilities of the GW4869-pretreated and untreated Synechococcus elongatus PCC 7942 to regulate endothelial angiogenesis were compared. The direct effects of the cyanobacterium-derived EVs (S. elongatus-EVs) on angiogenesis, wound healing and expressions of a class of pro-inflammatory factors that have regulatory roles in wound healing were also examined. Results: Synechococcus elongatus PCC 7942 treatment under light and dark conditions both significantly promoted angiogenesis and burn wound repair in mice. In vitro, the cyanobacterium enhanced angiogenic activities of endothelial cells, but the effects were markedly blocked by GW4869 pretreatment. S. elongatus-EVs were capable of augmenting endothelial angiogenesis in vitro, and stimulating new blood vessel formation and burn wound healing in mice. The expression of interleukin 6 (IL-6), which has an essential role in angiogenesis during skin wound repair, was induced in wound tissues and wound healing-related cells by S. elongatus-EVs and Synechococcus elongatus PCC 7942. Conclusion: Synechococcus elongatus PCC 7942 has the potential as a promising strategy for therapeutic angiogenesis and wound healing primarily by the delivery of functional EVs, not by its photosynthetic activity. The promotion of IL-6 expression may be a mechanism of the cyanobacterium and its EVs-induced pro-angiogenic and -wound healing effects.

6.
Metabolism ; 95: 93-101, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30668962

RESUMO

OBJECTIVE: Senile osteoporosis is one of the most common age-related diseases worldwide. Accumulating evidences have indicated that young blood can reverse age-related impairments. Extracellular vesicles (EVs) exert therapeutic effects in a variety of diseases by delivering bioactive molecules such as microRNAs (miRNAs). The aim of the study is to evaluate the therapeutic potential of EVs from human umbilical cord blood plasma (UCB-EVs) on senile osteoporosis and to preliminarily clarify the underlying mechanism. METHODS: UCB-EVs were injected into the tail vein of aged (16 months old) male C57BL/6 mice. Microcomputed tomography was performed to evaluate bone mass and microarchitecture of mice. The osteogenic and osteoclastic activities were determined by quantitative real-time PCR (qRT-PCR), histological examination and western blot analysis. In vitro, qRT-PCR assay was undertaken to explore the enrichment levels of a number of miRNAs that have positive effects in reducing bone loss. The efficacy of UCB-EVs on osteoblastic differentiation of bone marrow mesenchymal stromal cells (BMSCs) and osteoclastogenesis of RAW264.7 cells were assessed by cytochemical staining. Gene and protein expression changes were detected by qRT-PCR and western blotting respectively. Meanwhile, the roles of the selected miRNA in the regulatory effects of UCB-EVs on BMSCs and RAW264.7 cells were evaluated by using specific miRNA inhibitor. RESULTS: The intravenous injection of UCB-EVs for two months attenuated bone loss in old mice, as defined by increased trabecular and cortical bone mass, enhanced osteoblast formation and reduced osteoclast formation compared to the control mice. In vitro, UCB-EVs could promote the osteogenic differentiation of BMSCs and inhibit the osteoclastogenesis of RAW264.7 cells. Moreover, it was confirmed that miR-3960 was highly enriched in UCB-EVs and miR-3960 inhibitor reversed the stimulatory effect of UCB-EVs on osteoblastic differentiation of BMSCs. CONCLUSION: Our findings indicate that UCB-EVs ameliorate age-related bone loss by stimulating bone formation and inhibiting bone resorption, and miR-3960 mediated the osteogenic effect of UCB-EVs on BMSCs. Thus, UCB-EVs may represent a promising agent for prevention of senile osteoporosis.

7.
Dalton Trans ; 48(5): 1686-1692, 2019 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-30617366

RESUMO

A 3d-4f heterometallic metallacrown with formula of [EuCu5(quinha)5(sal)2(py)5]CF3SO3·py·3H2O (1) (H2quinha = quinaldichydroxamic acid; Hsal = salicylaldehyde) has been synthesized. This complex shows field-induced slow magnetic relaxation via a Raman-like process, where studies of the isostructural {LuCu5} (2) and {YCu5} (3) complexes show that the slow dynamics mainly arise from the {Cu5} S = 1/2 ground state rather than the EuIII ion. However, the EuIII ion enhances the relaxation rates of the {Cu5} unit which likely arises from second-order effects in the formally diamagnetic 7F0 ground state of EuIII.

8.
Chem Sci ; 9(41): 7986-7991, 2018 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-30450182

RESUMO

The on-off switching of spin-crossover (SCO) and single-molecule magnetism (SMM) remains highly attractive, especially if it involves dynamic crystal-to-crystal transformation. Herein we report the first molecule, a mononuclear cobalt(ii) complex, that exhibits on-off switching between SCO and SMM reversibly during crystal-to-crystal transformation. Subtle structural transformation triggered by a simple dehydration-rehydration process induces significant geometrical changes of the CoII center and modification of the supramolecular interactions and switches its colour and magnetic properties (dark red/SCO-on/SMM-off ↔ orange/SCO-off/SMM-on). This work suggests that modification of the weak supramolecular interactions could be very effective in achieving switchable materials involving both SCO and SMM properties.

9.
Cell Physiol Biochem ; 50(3): 1068-1083, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30355920

RESUMO

BACKGROUND/AIMS: Recently, we and others showed that the relative abundance of a specific vessel subtype, strongly positive for CD31 and Endomucin (CD31hiEmcnhi), is associated with bone formation and bone loss, and platelet-derived growth factor-BB (PDGF-BB) secreted by preosteoclasts induces the formation of the specific vessels and thereby stimulates osteogenesis. Inhibition of Src homology 2 domain-containing protein tyrosine phosphatase-2 (SHP-2) has been shown to block the fusion of preosteoclasts into mature osteoclasts. However, it is unclear whether inhibition of SHP-2 could promote preosteoclast-induced angiogenesis and then enhance bone formation. This study aimed to determine the effects of a specific SHP-2 inhibitor (NSC-87877) on CD31 hiEmcnhi vessel and bone formation. METHODS: 3-month-old C57BL/6 mice were subjected to either ovariectomy (OVX) or sham operation. OVX mice were intraperitoneally injected with NSC-87877 and the control (sham) mice were treated with an equal volume of diluents (PBS). Two months later, bone samples from mice were collected for µCT, histological, immunohistochemical and immunofluorescent analyses to assess bone mass, osteogenic and osteoclastic acitivities, as well as the densities of CD31hiEmcnhi vessels. A series of angiogenesis- related assays were performed to test the effects of NSC-87877 on the pro-angiogenic activities of preosteoclasts in vitro. RESULTS: We found that NSC-87877 is sufficient to induce bone-sparing effects in OVX-induced osteoporotic mouse model. We also found that NSC-87877 induces higher numbers of preosteoclasts and CD31hiEmcnhi vessels and higher levels of PDGF-BB in bone marrow of osteoporotic mice. In vitro assays showed that NSC-87877 prevents preosteoclast fusion, increases PDGF-BB production, and augments the pro-angiogenic abilities of preosteoclasts. CONCLUSION: Our results suggest that NSC-87877 can be used as a promising therapeutic agent for osteoporosis by inhibiting osteoclast formation and promoting preosteoclast-induced angiogenesis.


Assuntos
Osteogênese/efeitos dos fármacos , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Quinolinas/farmacologia , Animais , Becaplermina , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/patologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Neovascularização Fisiológica/efeitos dos fármacos , Osteoporose/patologia , Osteoporose/prevenção & controle , Osteoporose/veterinária , Ovariectomia , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 11/antagonistas & inibidores , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Proteínas Proto-Oncogênicas c-sis/metabolismo , Quinolinas/uso terapêutico , Ligante RANK/metabolismo , Células RAW 264.7 , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Microtomografia por Raio-X
10.
Theranostics ; 8(9): 2435-2446, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29721090

RESUMO

Recently, researchers identified a distinct vessel subtype called type H vessels that couple angiogenesis and osteogenesis. We previously found that type H vessels are reduced in ovariectomy (OVX)-induced osteoporotic mice, and preosteoclasts are able to secrete platelet-derived growth factor-BB (PDGF-BB) to stimulate type H vessel formation and thereby to promote osteogenesis. This study aimed to explore whether harmine, a ß-carboline alkaloid, is capable of preventing bone loss in OVX mice by promoting preosteoclast PDGF-BB-induced type H vessel formation. METHODS: The impact of harmine on osteoclastogenesis of RANKL-stimulated RAW264.7 cells was verified by gene expression analysis and tartrate-resistant acid phosphatase (TRAP) staining. Enzyme-linked immunosorbent assay (ELISA) was conducted to test PDGF-BB production by preosteoclasts. A series of angiogenesis-related assays in vitro were performed to assess the pro-angiogenic effects of the conditioned media from RANKL-stimulated RAW264.7 cells treated with or without harmine. Meanwhile, the role of PDGF-BB in this process was determined. In vivo, OVX mice were intragastrically administrated with harmine emulsion or an equal volume of vehicle. 2 months later, bone samples were collected for µCT, histological, immunohistochemical and immunofluorescent analyses to evaluate bone mass, osteogenic and osteoclastic activities, as well as the numbers of type H vessels. Bone marrow PDGF-BB concentrations were assessed by ELISA. RESULTS: Exposure of RANKL-stimulated RAW264.7 cells to harmine enhanced the formation of preosteoclasts and the production of PDGF-BB. Harmine augmented the ability of RANKL-stimulated RAW264.7 cells to promote angiogenesis of endothelial cells, whereas the effect was blocked by PDGF-BB inhibition. In vivo, the oral administration of harmine emulsion to OVX mice resulted in enhanced trabecular bone mass and osteogenic responses, increased numbers of preosteoclasts, as well as reduced numbers of osteoclasts and fat cells. Moreover, OVX mice treated with harmine exhibited higher levels of bone marrow PDGF-BB and much more type H vessels in bone. CONCLUSION: Harmine may exert bone-sparing effects by suppression of osteoclast formation and promotion of preosteoclast PDGF-BB-induced angiogenesis.

11.
Bone Res ; 6: 9, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29619269

RESUMO

Osteoporosis is a frequent complication of chronic inflammatory diseases and increases in the pro-inflammatory cytokines make an important contribution to bone loss by promoting bone resorption and impairing bone formation. Omentin-1 is a newly identified adipocytokine that has anti-inflammatory effects, but little is known about the role of omentin-1 in inflammatory osteoporosis. Here we generated global omentin-1 knockout (omentin-1-/-) mice and demonstrated that depletion of omentin-1 induces inflammatory bone loss-like phenotypes in mice, as defined by abnormally elevated pro-inflammatory cytokines, increased osteoclast formation and bone tissue destruction, as well as impaired osteogenic activities. Using an inflammatory cell model induced by tumor necrosis factor-α (TNF-α), we determined that recombinant omentin-1 reduces the production of pro-inflammatory factors in the TNF-α-activated macrophages, and suppresses their anti-osteoblastic and pro-osteoclastic abilities. In the magnesium silicate-induced inflammatory osteoporosis mouse model, the systemic administration of adenoviral-delivered omentin-1 significantly protects from osteoporotic bone loss and inflammation. Our study suggests that omentin-1 can be used as a promising therapeutic agent for the prevention or treatment of inflammatory bone diseases by downregulating the pro-inflammatory cytokines.

12.
Theranostics ; 8(6): 1607-1623, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29556344

RESUMO

Chronic non-healing wounds represent one of the most common complications of diabetes and need advanced treatment strategies. Exosomes are key mediators of cell paracrine action and can be directly utilized as therapeutic agents for tissue repair and regeneration. Here, we explored the effects of exosomes from human urine-derived stem cells (USC-Exos) on diabetic wound healing and the underlying mechanism. Methods: USCs were characterized by flow cytometry and multipotent differentiation potential analyses. USC-Exos were isolated from the conditioned media of USCs and identified by transmission electron microscopy and flow cytometry. A series of functional assays in vitro were performed to assess the effects of USC-Exos on the activities of wound healing-related cells. Protein profiles in USC-Exos and USCs were examined to screen the candidate molecules that mediate USC-Exos function. The effects of USC-Exos on wound healing in streptozotocin-induced diabetic mice were tested by measuring wound closure rates, histological and immunofluorescence analyses. Meanwhile, the role of the candidate protein in USC-Exos-induced regulation of angiogenic activities of endothelial cells and diabetic wound healing was assessed. Results: USCs were positive for CD29, CD44, CD73 and CD90, but negative for CD34 and CD45. USCs were able to differentiate into osteoblasts, adipocytes and chondrocytes. USC-Exos exhibited a cup- or sphere-shaped morphology with a mean diameter of 51.57 ± 2.93 nm and positive for CD63 and TSG101. USC-Exos could augment the functional properties of wound healing-related cells including the angiogenic activities of endothelial cells. USC-Exos were enriched in the proteins that are involved in regulation of wound healing-related biological processes. Particularly, a pro-angiogenic protein called deleted in malignant brain tumors 1 (DMBT1) was highly expressed in USC-Exos. Further functional assays showed that DMBT1 protein was required for USC-Exos-induced promotion of angiogenic responses of cultured endothelial cells, as well as angiogenesis and wound healing in diabetic mice. Conclusion: Our findings suggest that USC-Exos may represent a promising strategy for diabetic soft tissue wound healing by promoting angiogenesis via transferring DMBT1 protein.

13.
Theranostics ; 8(1): 169-184, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29290800

RESUMO

The application of blood plasma for soft tissue wound healing is receiving much more attention recently. Exosomes are critical paracrine mediators that can be obtained from biological fluids including plasma and be able to induce regenerative effects by transferring bioactive molecules such as microRNAs (miRNAs). This study aimed to investigate the effects of exosomes from human umbilical cord blood plasma (UCB-Exos) on wound healing and to elucidate the underlying mechanism. Methods: UCB-Exos were isolated by ultracentrifugation and subcutaneously injected into full-thickness skin wounds in mice. The efficacy of UCB-Exos on wound healing was evaluated by measuring wound closure rates, histological analysis and immunofluorescence examinations. In vitro, quantitative real-time PCR (qRT-PCR) analysis was performed to detect the expression levels of a class of miRNAs that have positive roles in regulating wound healing. The scratch wound assay, transwell assay and cell counting kit-8 analysis were conducted to assess the effects of UCB-Exos on migration and proliferation of human skin fibroblasts and endothelial cells. Tube formation assay was carried out to test the impact of UCB-Exos on angiogenic tube formation ability of endothelial cells. Meanwhile, by using specific RNA inhibitors or siRNAs, the roles of the candidate miRNA and its target genes in UCB-Exos-induced regulation of function of fibroblasts and endothelial cells were assessed. Results: The local transplantation of UCB-Exos into mouse skin wounds resulted in accelerated re-epithelialization, reduced scar widths, and enhanced angiogenesis. In vitro, UCB-Exos could promote the proliferation and migration of fibroblasts, and enhance the angiogenic activities of endothelial cells. Notably, miR-21-3p was found to be highly enriched in UCB-Exos and served as a critical mediator in UCB-Exos -induced regulatory effects through inhibition of phosphatase and tensin homolog (PTEN) and sprouty homolog 1 (SPRY1). Conclusion: Our results suggest that UCB-Exos are important effectors of plasma activity and can be used as a novel promising strategy for soft tissue wound healing.


Assuntos
Exossomos/fisiologia , Sangue Fetal/metabolismo , MicroRNAs/metabolismo , Animais , Movimento Celular/genética , Movimento Celular/fisiologia , Proliferação de Células/genética , Proliferação de Células/fisiologia , Células Cultivadas , Exossomos/metabolismo , Fibroblastos/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Neovascularização Fisiológica , Cicatrização/genética , Cicatrização/fisiologia
14.
Cell Biol Int ; 42(5): 580-588, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29323455

RESUMO

Osteosarcoma represents the most common primary malignant bone tumor in children and adolescents, which shows severe resistance toward standard chemotherapy because of high invasive capacity and growing incidence. Selenocysteine (SeC) is a naturally available Se-containing amino acid that displays splendid anticancer activities against several human tumors. However, little information about SeC-induced growth inhibition against human osteosarcoma is available. Herein, the anticancer efficiency and underlying mechanism of SeC against human osteosarcoma were evaluated in vitro and in vivo. The results revealed that SeC significantly inhibited MG-63 human osteosarcoma cells growth in vitro through induction of S-phase arrest and apoptosis, as reflected by the decrease of cyclin A and CDK-2, PARP cleavage, and caspases activation. SeC treatment also resulted in mitochondrial dysfunction through affecting Bcl-2 family expression. Moreover, SeC triggered p53 phosphorylation by inducing reactive oxygen species (ROS) overproduction. ROS inhibition effectively blocked SeC-induced cytotoxicity and p53 phosphorylation. Importantly, MG-63 human osteosarcoma xenograft growth in nude mice was significantly suppressed in vivo through triggering apoptosis and p53 phosphorylation. These results indicated that SeC had the potential to inhibit human osteosarcoma cells growth in vitro and in vivo through triggering mitochondrial dysfunction and ROS-mediated p53 phosphorylation, which validated the potential application of Se-containing compounds in treatment of human osteosarcoma.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Ósseas/tratamento farmacológico , Mitocôndrias/efeitos dos fármacos , Osteossarcoma/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo , Selenocisteína/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Animais , Antineoplásicos/uso terapêutico , Apoptose , Neoplasias Ósseas/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Camundongos Nus , Mitocôndrias/metabolismo , Osteossarcoma/patologia , Fosforilação , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Pontos de Checagem da Fase S do Ciclo Celular/efeitos dos fármacos , Selenocisteína/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Environ Sci Pollut Res Int ; 24(35): 27573-27586, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28980103

RESUMO

In recent years, international research on the toxicity of the heavy metal, antimony, has gradually changed focus from early medical and pharmacological toxicology to environmental toxicology and ecotoxicology. However, little research has been conducted for sources identification and risk management of heavy metals pollution by long-term antimony mining activities. In this study, a large number of investigations were conducted on the temporal and spatial distribution of antimony and related heavy metal contaminants (lead, zinc, and arsenic), as well as on the exposure risks for the population for the Yuxi river basin in the Hunan province, China. The scope of the investigations included mine water, waste rock, tailings, agricultural soil, surface water, river sediments, and groundwater sources of drinking water. Health and ecological risks from exposure to heavy metal pollution were evaluated. The main pollution sources of heavy metals in the Yuxi River basin were analyzed. Remediation programs and risk management strategies for heavy metal pollution were consequently proposed. This article provides a scientific basis for the risk assessment and management of heavy metal pollution caused by antimony basin ore mining.


Assuntos
Antimônio , Monitoramento Ambiental/métodos , Metais Pesados/análise , Mineração , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , China , Água Subterrânea/química , Humanos , Medição de Risco , Rios/química , Solo/química
16.
Cell Physiol Biochem ; 43(1): 320-330, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28854422

RESUMO

BACKGROUND/AIMS: This study aimed to explore the effects of the long non-coding RNA HOST2 (lnc-HOST2) on the proliferation, migration, invasion and apoptosis of osteosarcoma cells. METHODS: Osteosarcoma tissues and adjacent normal tissues from 52 patients were selected. Human osteosarcoma cell lines (SaOS2, HOS, U2OS and MG-63) were collected and cultured; MG-63 cells had the highest lnc-HOST2 expression and thus were used in subsequent experiments. Then, MG-63 cells were transfected and divided into the blank (no transfection), si-CON (transfected with negative control siRNA) and si-lnc-HOST2 (transfected with small interference lnc-HOST2 siRNA) groups. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to determine the expression of lnc-HOST2 in primary tissues and cells. Cell growth was detected using the CCK-8 and colony formation assays. Cell doubling time was detected. Cell migration and invasion were observed using the scratch test and Transwell assays. Cell apoptosis and cell cycle progression of osteosarcoma cells were detected using flow cytometry with annexin V/PI double staining and PI staining, respectively. RESULTS: The level of lnc-HOST2 expression in the si-lnc-HOST2 group was significantly decreased compared to that in the blank and si-CON groups. The OD values in the si-lnc-HOST2 group were significantly lower than those in the blank and si-CON groups. Compared to the blank and si-CON groups, the si-lnc-HOST2 group presented significant decreases in the colony number and healing rates after scratching. The number of invasive cells in the si-lnc-HOST2 group was significantly less than that in the blank and si-CON groups. In the si-lnc-HOST2 group, the cell cycle was mainly halted in the G1 phase, and the apoptosis rate and doubling time in this group were significantly higher than those in the blank group and si-CON group. CONCLUSIONS: Inhibition of lnc-HOST2 could suppress the proliferation, migration, and invasion and promote the apoptosis of osteosarcoma cells.


Assuntos
Neoplasias Ósseas/patologia , Osteossarcoma/patologia , RNA Longo não Codificante/metabolismo , Adolescente , Apoptose , Neoplasias Ósseas/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Criança , Feminino , Pontos de Checagem da Fase G1 do Ciclo Celular , Humanos , Masculino , Osteossarcoma/metabolismo , Interferência de RNA , RNA Longo não Codificante/antagonistas & inibidores , RNA Longo não Codificante/genética , RNA Interferente Pequeno/metabolismo
17.
Food Chem ; 234: 303-313, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28551240

RESUMO

Jackfruit (Artocarpus heterophyllus Lam.) peel is an underutilized by-product in both, the production and processing of jackfruit. This research compared the antioxidant and hypoglycemic potential of jackfruit peel with jackfruit pulp, flake and seed for the first time. The phytochemical profile of peel extract was characterized with HPLC-QTOF-MS/MS. Results revealed that peel extract exhibited the highest total phenolic and total flavonoid content, and the phenolics was 4.65, 4.12 and 4.95 times higher than that of pulp, flake and seed extract, respectively. The strongest DPPH and ABTS+ scavenging ability, α-glucosidase inhibition were also found in peel extract, and the α-glucosidase inhibition was about 11.8-fold of that of acarbose. The HPLC-QTOF-MS/MS analysis led to the tentative identification of 53 compounds, prenylflavonoids, hydroxycinnamic acids and glycosides are the predominant bioactive compounds. Above results reveal promising potential of jackfruit peel as a new source of natural antioxidants and hypoglycemic agents.


Assuntos
Antioxidantes/química , Artocarpus/química , Frutas/química , Inibidores de Glicosídeo Hidrolases/química , Compostos Fitoquímicos/química , Cromatografia Líquida de Alta Pressão , Extratos Vegetais/química , Sementes/química , Espectrometria de Massas em Tandem , alfa-Glucosidases
18.
J Am Chem Soc ; 139(1): 373-380, 2017 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-27936686

RESUMO

The pursuit of single-molecule magnets (SMMs) with better performance urges new molecular design that can endow SMMs larger magnetic anisotropy. Here we report that two-coordinate cobalt imido complexes featuring highly covalent Co═N cores exhibit slow relaxation of magnetization under zero direct-current field with a high effective relaxation barrier up to 413 cm-1, a new record for transition metal based SMMs. Two theoretical models were carried out to investigate the anisotropy of these complexes: single-ion model and Co-N coupling model. The former indicates that the pseudo linear ligand field helps to preserve the first-order orbital momentum, while the latter suggests that the strong ferromagnetic interaction between Co and N makes the [CoN]+ fragment a pseudo single paramagnetic ion, and that the excellent performance of these cobalt imido SMMs is attributed to the inherent large magnetic anisotropy of the [CoN]+ core with |MJ = ± 7/2⟩ ground Kramers doublet.

19.
Heart Lung Circ ; 26(1): 94-100, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27425182

RESUMO

BACKGROUND: Degradable collagen-chitosan composite materials have been used to fabricate tissue engineered heart valves. The aims of this study were to demonstrate that the collagen-chitosan composite scaffolds are cytocompatible, and endothelial cells can be differentiated from bone marrow mesenchymal stem cells (BMSCs) when seeded onto the scaffolds. The adhesion and biological activities of the seeded cells were also investigated. METHODS: Collagen-chitosan composite material was used as the cell matrix, and smooth muscle cells, fibroblasts and BMSCs were used as seed cells. After four weeks of in vitro culture, the smooth muscle cells, fibroblasts, and BMSCs were sequentially seeded into the collagen-chitosan composite material. After four weeks in culture, the cellular density and activity were assessed on segments of the tissue engineered heart valve scaffolds to determine the cell viability and proliferation in the collagen-chitosan composite material. RESULTS: The tissue engineered heart valves stained positively for both smooth muscle actin and endothelial cell factor VIII, suggesting that the seeded cells were in fact smooth muscle cells, fibroblasts, and endothelial cells. The 6-ketone prostaglandin content, as measured by radioimmunoassay, of the collagen-chitosan cell culture fluid was higher than that of the serum-free medium (P <0.01). Light and electron microscopy showed that the seeded cells had shapes similar to the morphology of smooth muscle cells, fibroblasts, and endothelial cells. CONCLUSIONS: Endothelial cells can be differentiated from BMSCs when seeded onto the collagen-chitosan composite scaffolds. The seeded cells retained their biological activity after being cultured in vitro and seeded into the collagen-chitosan composite material.


Assuntos
Implantes Absorvíveis , Quitosana/química , Colágeno/química , Fibroblastos/metabolismo , Valvas Cardíacas , Miócitos de Músculo Liso/metabolismo , Engenharia Tecidual , Animais , Células Cultivadas , Fibroblastos/classificação , Miócitos de Músculo Liso/citologia , Coelhos
20.
Huan Jing Ke Xue ; 38(10): 4141-4150, 2017 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-29965197

RESUMO

Large-scale cyanobacteria bloom occurred in the summer of 2014 in the Guishi Reservoir that is an important drinking water source for Hezhou City. The dynamic change regularity, external pollution sources, and the phytoplankton community characteristics during the bloom were investigated to evaluate the eutrophication in the reservoir and to present effective prevention and control measures. The results showed that nitrogen and phosphorus concentrations increased year by year; water quality on some sites has been out of class Ⅱ of national water quality standards; and the main pollution source was the agricultural non-point sources. Phytoplankton cell density was in the range of 8.60×106-5.36×108 cells·L-1 and chlorophyll a concentrations reached 74.48 µg·L-1 during the bloom. The dominant species was Microcystis wesenbergii whose density reached 5.36×108 cells·L-1. The cell density decreased over time and concentrated on the surface and at the depth of 2 m underwater. The total phytoplankton cell density was strongly correlated to total phosphorus, total nitrogen, nitrate nitrogen, and the permanganate index, and was inversely correlated to transparency. The water in the Guishi Reservoir was not polluted by microcystic toxins. Moreover, Guishi Reservoir is in a meso-eutrophic state; therefore, the prevention and control of the cyanobacteria bloom should focus on weather conditions and on reducing the input of nitrogen and phosphorus to keep the nutrient levels low.

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