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1.
J Biol Chem ; 296: 100635, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33823156

RESUMO

The methyltransferases MLL3 and MLL4 primarily catalyze the monomethylation of histone H3 lysine 4 (H3K4) on enhancers to regulate cell-type-specific gene expression and cell fate transition. MLL3 and MLL4 share almost identical binding partners and biochemical activities, but perform specific and nonredundant functions. The features and functions that distinguish MLL3 and MLL4 remain elusive. Here, we characterize the kinetic mechanisms of MLL3 and MLL4 ternary complexes containing the catalytic SET domain from MLL3 or MLL4 (MLL3SET or MLL4SET), the SPRY domain of ASH2L (ASH2LSPRY), and a short fragment of RBBP5 (RBBP5AS-ABM) to search for possible explanations. Steady-state kinetic analyses and inhibition studies reveal that the MLL3 complex catalyzes methylation in a random sequential bi-bi mechanism. In contrast, the MLL4 complex adopts an ordered sequential bi-bi mechanism, in which the cofactor S-adenosylmethionine (AdoMet) binds to the enzyme prior to the H3 peptide, and the methylated H3 peptide dissociates from the enzyme before S-adenosylhomocysteine (AdoHcy) detaches after methylation. Substrate-binding assays using fluorescence polarization (FP) confirm that AdoMet binding is a prerequisite for H3 binding for the MLL4 complex but not for the MLL3 complex. Molecular dynamic simulations reveal that the binding of AdoMet exclusively induces conformational constraints on the AdoMet-binding groove and the H3 substrate-binding pocket of MLL4, therefore stabilizing a specific active conformation to ease entry of the substrate H3. The distinct kinetic mechanisms and conformational plasticities provide important insights into the differential functions of MLL3 and MLL4 and may also guide the development of selective inhibitors targeting MLL3 or MLL4.


Assuntos
Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Histona-Lisina N-Metiltransferase/química , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Processamento de Proteína Pós-Traducional , Catálise , Proteínas de Ligação a DNA/genética , Histona-Lisina N-Metiltransferase/genética , Histonas/química , Humanos , Cinética , Metilação , Ligação Proteica
2.
Gen Comp Endocrinol ; 225: 61-70, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26407501

RESUMO

In pregnancy, placenta can be exposed to glucocorticoids (GCs) via several ways, which may disturb placentation and adversely affect pregnancy. Preeclampsia (PE) is thought to be attributed, in part, to impaired trophoblast development. The purpose of the present study was to confirm that GC exposure in early placentation could lead to PE in rats, with the mechanisms involving dysregulated trophoblast development. In the study, pregnant rats were administered with 2.5mg/kg Dex subcutaneously once per day from gestational day 7 to 13. Maternal systolic blood pressure and urinary albumin were increased, while both fetus and placenta were restricted after GC exposure relative to the control group. GC exposure also contributed to placental abnormalities and renal impairment. Moreover, placental oxidative damage was increased along with placental hypoxia-inducible factor 1-alpha (HIF1A) overexpression after GC treatment. Mechanically, GC induced PE in rat partially through inhibiting trophoblast proliferation, migration, invasion and epithelial-mesenchymal transition (EMT), which involved phospho-extracellular signal regulated kinase (p-ERK) downregulation. Furthermore, GC receptor was required for the inhibition of GC on trophoblast proliferation, migration, invasion and EMT in vitro. These findings suggest that GC exposure in early placentation could contribute to PE in pregnant rats, with the mechanisms involving inhibition of trophoblast proliferation, migration, invasion and EMT by GC.


Assuntos
Dexametasona/farmacologia , Glucocorticoides/farmacologia , Placenta/efeitos dos fármacos , Placentação/efeitos dos fármacos , Pré-Eclâmpsia/induzido quimicamente , Trofoblastos/efeitos dos fármacos , Animais , Regulação para Baixo/efeitos dos fármacos , Feminino , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Estresse Oxidativo/efeitos dos fármacos , Placenta/metabolismo , Placenta/patologia , Pré-Eclâmpsia/metabolismo , Pré-Eclâmpsia/patologia , Gravidez , Ratos , Trofoblastos/metabolismo , Trofoblastos/patologia
3.
Biol Reprod ; 90(4): 74, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24571985

RESUMO

Inflammation dysregulation in placenta is implicated in the pathogenesis of numerous pregnancy complications. Glucocorticoids (GCs), universally considered anti-inflammatory, can also exert proinflammatory actions under some conditions, whereas whether and how GCs promote placental inflammation have not been intensively investigated. In this paper we report the opposing regulation of rat placental inflammation by synthetic GC dexamethasone (Dex). When Dex was subcutaneously injected 1 h after we administered an intraperitoneal lipopolysaccharide (LPS) challenge, neutrophil infiltration and proinflammatory Il1b, Il6, and Tnfa expression in rat placenta were significantly reduced. In contrast, Dex pretreatment for 24 h potentiated rat placental proinflammatory response to LPS and delayed inflammation resolution, which involved MAPKs and NF-kappaB activation. Mechanically, Dex pretreatment promoted 5-lipoxygenase (ALOX5) activation and increased leukotriene B4 production, whereas it inhibited the anti-inflammatory and proresolving lipid mediator lipoxin A4 (LXA4) biosynthesis in rat placenta via downregulating ALOX15 and ALOX15B expression. Moreover, LXA4 supplementation dampened Dex-potentiated placental inflammation and suppressed Dex-mediated ALOX5 activation in vivo and in vitro. Taken together, these findings suggest that GCs exposure could promote placental inflammation initiation and delay resolution via disrupting LXA4 biosynthesis.


Assuntos
Dexametasona/farmacologia , Glucocorticoides/farmacologia , Inflamação/imunologia , Lipoxinas/imunologia , Placenta/efeitos dos fármacos , Placenta/imunologia , Animais , Araquidonato 5-Lipoxigenase/imunologia , Araquidonato 5-Lipoxigenase/metabolismo , Ácido Araquidônico/imunologia , Linhagem Celular , Dexametasona/imunologia , Dinoprostona/imunologia , Dinoprostona/metabolismo , Feminino , Glucocorticoides/imunologia , Humanos , Inflamação/metabolismo , Leucotrieno B4/imunologia , Leucotrieno B4/metabolismo , Lipopolissacarídeos/imunologia , Lipopolissacarídeos/farmacologia , Lipoxinas/antagonistas & inibidores , Lipoxinas/biossíntese , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/imunologia , NF-kappa B/imunologia , NF-kappa B/metabolismo , Placenta/citologia , Gravidez , Ratos , Ratos Sprague-Dawley
4.
Reprod Biol Endocrinol ; 12: 77, 2014 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-25108313

RESUMO

BACKGROUND: Cadmium (Cd) is a major environmental pollutant that causes multiple adverse health effects in humans and animals. In this study, we investigated Cd-mediated toxic effects in rats during pregnancy and endocrine intervention in the placenta. METHODS: We exposed pregnant rats to intraperitoneal Cd (CdCl2) at various doses (0, 0.25, and 0.5 mg/kg BW/day) from days 5 to 19 of pregnancy and evaluated the maternal-placental-fetal parameters linked to preeclampsia. We measured the corticosterone level in rat serum and placental tissue by sensitive ELISA and also analyzed the expression of glucocorticoid synthesis enzymes in the placenta. RESULTS: Key features of preeclampsia (PE), including hypertension, proteinuria, glomerular endotheliosis, placental abnormalities and small fetal size, appeared in pregnant rats after injection with 0.5 mg/kg BW/day Cd. The placental corticosterone production and maternal and fetal plasma corticosterone levels were increased in rats treated with 0.5 mg/kg BW/day Cd (P <0.01). The expression of 21-hydroxylase (CYP21) and 11beta-hydroxylase (CYP11B1), enzymes essential for corticosteroid synthesis, were increased in Cd-exposed placenta (P <0.01). 11beta-hydroxysteroid dehydrogenase (11beta-HSD2), a dominant negative regulator of local glucocorticoid levels, was decreased in Cd-exposed placenta (P <0.01). CONCLUSIONS: Our study demonstrates for the first time that changes in placental glucocorticoid synthesis induced by Cd exposure during pregnancy could contribute to preeclamptic conditions in rats.


Assuntos
Intoxicação por Cádmio/fisiopatologia , Glucocorticoides/metabolismo , Placenta/efeitos dos fármacos , Pré-Eclâmpsia/etiologia , Complicações na Gravidez/fisiopatologia , Regulação para Cima/efeitos dos fármacos , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/antagonistas & inibidores , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/biossíntese , Animais , Cloreto de Cádmio/administração & dosagem , Cloreto de Cádmio/metabolismo , Cloreto de Cádmio/farmacocinética , Cloreto de Cádmio/toxicidade , Intoxicação por Cádmio/sangue , Intoxicação por Cádmio/metabolismo , Intoxicação por Cádmio/patologia , Corticosterona/sangue , Corticosterona/metabolismo , Relação Dose-Resposta a Droga , Poluentes Ambientais/administração & dosagem , Poluentes Ambientais/metabolismo , Poluentes Ambientais/farmacocinética , Poluentes Ambientais/toxicidade , Indução Enzimática/efeitos dos fármacos , Repressão Enzimática/efeitos dos fármacos , Feminino , Glucocorticoides/sangue , Injeções Intraperitoneais , Placenta/enzimologia , Placenta/metabolismo , Placenta/patologia , Gravidez , Complicações na Gravidez/sangue , Complicações na Gravidez/metabolismo , Complicações na Gravidez/patologia , Distribuição Aleatória , Ratos Sprague-Dawley , Esteroide 11-beta-Hidroxilase/biossíntese , Esteroide 21-Hidroxilase/biossíntese , Distribuição Tecidual
5.
ScientificWorldJournal ; 11: 1056-67, 2011 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-21552771

RESUMO

Excessive oxidative stress, decreased antioxidant capacity, and enhanced cellular calcium levels are initial factors that cause endothelial cell (EC) hyperpermeability, which represents a crucial event in the pathogenesis of pre-eclampsia. Lipoxin A4 (LXA4) strongly attenuated lipopolysaccharide (LPS)-induced hyperpermeability through maintaining the normal expression of VE-cadherin and â-catenin. This effect was mainly mediated by a specific LXA4 receptor. LXA4 could also obviously inhibit LPS-induced elevation of the cellular calcium level and up-regulation of the transient receptor potential protein family C 1, an important calcium channel in ECs. At the same time, LXA4 strongly blocked LPS-triggered reactive oxidative species production, while it promoted the expression of the NF-E2 related factor 2 (Nrf2) protein. Our findings demonstrate that LXA4 could prevent the EC hyperpermeability induced by LPS in human umbilical vein endothelial cells (HUVECs), under which the possible mechanism is through Nrf2 as well as Ca2+-sensitive pathways.


Assuntos
Permeabilidade da Membrana Celular , Células Endoteliais/efeitos dos fármacos , Lipoxinas/metabolismo , Pré-Eclâmpsia/fisiopatologia , Caderinas/metabolismo , Cálcio/metabolismo , Células Cultivadas , Células Endoteliais/metabolismo , Feminino , Humanos , Lipopolissacarídeos/efeitos adversos , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Pré-Eclâmpsia/metabolismo , Gravidez , Espécies Reativas de Oxigênio/metabolismo , Veias Umbilicais/citologia , beta Catenina/metabolismo
6.
Zhonghua Fu Chan Ke Za Zhi ; 46(3): 199-204, 2011 Mar.
Artigo em Zh | MEDLINE | ID: mdl-21575454

RESUMO

OBJECTIVE: To explore whether lipoxin A(4) (LXA(4))could prevent lipopolysaccharide (LPS)-induced human umbilical vein endothelial cells (HUVEC) monolayer hyperpermeability and its possible mechanism. METHODS: Human umbilical cords were obtained from women with normal pregnancy immediately after delivery from Tongji Hospital Affiliated of Tongji Medical College. Primary HUVEC were isolated from umbilical veins and subcultured, then, HUVEC were divided into four groups:control group; LPS group (10 mg/L of LPS); LPS + LXA(4) group(10 mg/L of LPS and 100 nmol/L of LXA(4)); LPS + LXA(4) + BOC-2 group [10 µmol/L of BOC-2, an effective antagonist of formyl peptide receptor like 1 (FPRL-1)]. All expriments were performed after cells were treated for 24 hours. Endothelial permeability was measured by fluorescein isothiocyan-ate labelled bovine serum albumin (FITC-BSA) clearance across the monolayer; tumor necrosis factor α (TNF-α) mRNA and secretion were detected by reverse transcriplase (RT)-PCR and ELISA assay respectively, and nuclear factor κB (NF-κB) protein change was determined by western blot. RESULTS: (1) LPS induced a significant increase in the permeability [Pa value of LPS group was (183.1 ± 1.7)%], while co-administrating with LXA(4) obviously attenuated this LPS-induced hyperpermeability, Pa value of LPS + LXA(4) group was (103.1 ± 2.2)%, LPS + LXA(4) + BOC-2 group was (162.2 ± 2.8)%, control group was 100%, the permeability of HUVEC monolayer was significantly increased by LPS which was (83.1 ± 1.7)% of control (P < 0.01), however, it was notably inhibited by LXA(4) (P < 0.05); the blockade of FPRL-1 could attenuate the effect of LXA(4), that is, there was no difference between the LPS + LXA(4) + BOC-2 group and the LPS group. (2) After treatment with different concentration of LPS(0, 0.1, 1, 10 mg/L), the mRNA expressions of TNF-α were increased (1.11 ± 0.11, 1.27 ± 0.03, 1.60 ± 0.06, 1.82 ± 0.04, respectively), compared with the control group, at the concentration of 1, 10 mg/L LPS, the difference was statistically significant (P < 0.05). (3) The increased levels of NF-κB and inflammatory mediator TNF-α in the LPS group were both inhibited by LXA(4). Levels of NF-κB protein and TNF-α mRNA secretion in LPS treated group (0.53 ± 0.06 and 0.81 ± 0.09, respectively) were both inhibited by LXA(4)(0.19 ± 0.05 and 0.41 ± 0.07, respectively, and both had significant difference, P < 0.05). (4) Levels of TNF-α in HUVEC culture medium of LPS group [(31.94 ± 0.01) ng/L] was significantly higher than the control group [(18.17 ± 0.03) ng/L, P < 0.05], LPS + LXA(4) group [(15.72 ± 0.07) ng/L] was significantly lower than the LPS group (P < 0.05). CONCLUSION: Our findings demonstrated that LXA(4) could prevent the endothelial cell hyperpermeability induced by LPS in HUVEC under which the possible mechanism was through inhibiting the expression of NF-κB and its related cytokines through receptor-dependent.


Assuntos
Permeabilidade Capilar/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Lipoxinas/farmacologia , NF-kappa B/metabolismo , Células Cultivadas , Feminino , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Lipopolissacarídeos/efeitos adversos , Lipopolissacarídeos/antagonistas & inibidores , Lipoxinas/administração & dosagem , NF-kappa B/genética , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
7.
Environ Toxicol Pharmacol ; 81: 103512, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33096234

RESUMO

Ultraviolet (UV) radiation-induced chronic inflammation contributes to all stages of skin tumor development. In addition, gender plays an important role in inflammatory diseases or cancer. In this study, histopathology changes, hematology, oxidative stress and inflammatory response were used to evaluate sex differences in UV-induced chronic inflammation-associated cancer development. The results showed that the male and female mice had photoaging damage at the 9th week. However, skin tumors only appeared in male mice at 31st week. Furthermore, UV increased ROS production, p65, p-p65, IL-6 and TNF-α protein expressions in skin, and these factors elevated more in male mouse model. Hematology results showed that the parameters of blood systemic inflammation were changed in different degrees in model groups, while the pathological results showed inflammatory cell infiltration in the internal organs of both model groups in varying degrees. These results indicate that there are gender differences in UV-induced skin inflammation, carcinogenesis and systemic damage. Moreover, male mice are more sensitive to UV irradiation, which may be responsible to greater oxidative stress and inflammatory damage.


Assuntos
Neoplasias Cutâneas/etiologia , Pele/efeitos da radiação , Raios Ultravioleta/efeitos adversos , Animais , Carcinogênese , Feminino , Inflamação/etiologia , Inflamação/imunologia , Inflamação/patologia , Interleucina-6/imunologia , Rim/patologia , Rim/efeitos da radiação , Fígado/patologia , Fígado/efeitos da radiação , Masculino , Camundongos , Estresse Oxidativo/efeitos da radiação , Espécies Reativas de Oxigênio/imunologia , Caracteres Sexuais , Pele/imunologia , Pele/patologia , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/patologia , Baço/patologia , Baço/efeitos da radiação , Timo/patologia , Timo/efeitos da radiação , Fator de Necrose Tumoral alfa/imunologia
8.
J Huazhong Univ Sci Technolog Med Sci ; 30(6): 767-70, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21181369

RESUMO

This study examined in vitro effect of lipoxin A(4) (LXA(4)) on interleukin-1ß (IL-1ß) production of monocytes and its possible mechanism in severe preeclampsia (PE). Peripheral venous blood was drawn from 15 patients with severe preeclampsia (PE group) and 20 normal pregnant women (control group) to prepare monocytes which were then treated with LXA(4) at different concentrations of 0, 10, 100 nmol/L respectively. IL-1ß level in the supernatant of monocytes was detected by enzyme linked immunoassay. The [Ca(2+)](i) of monocytes was measured by laser scanning confocal microscopy. The results showed that the IL-1ß level and the [Ca(2+)](i) of monocytes in the PE group were significantly higher than those in the control group. LXA(4) significantly decreased the generation of IL-1ß in a dose-dependent manner in the PE group. After treatment with 100-nmol/L LXA(4), in the PE group, the [Ca(2+)](i) concentration of monocytes was significantly reduced. It was concluded that LXA(4) may inhibit the IL-1ß production of monocytes from severe preeclampsia women by inhibiting extracellular calcium influx.


Assuntos
Interleucina-1beta/biossíntese , Lipoxinas/farmacologia , Monócitos/metabolismo , Pré-Eclâmpsia/fisiopatologia , Adulto , Anti-Inflamatórios não Esteroides/farmacologia , Cálcio/metabolismo , Células Cultivadas , Feminino , Humanos , Monócitos/citologia , Pré-Eclâmpsia/sangue , Gravidez
9.
Zhonghua Fu Chan Ke Za Zhi ; 45(11): 848-53, 2010 Nov.
Artigo em Zh | MEDLINE | ID: mdl-21211285

RESUMO

OBJECTIVE: To explore the effects of lipoxin A(4) (LXA(4)) on lipopolysaccharide (LPS)-induced oxidative stress in human umbilical veins endothelial cells (HUVEC) and the possible mechanism. METHODS: Neonatal umbilical cords were obtained from normal term pregnant women with cesarean section within 4 hours and then were used to isolate HUVEC for subculture. HUVEC were divided into four groups:control group; LPS group (10 µg/ml of LPS); LPS + LXA(4) group (10 µg/ml of LPS and 100 nmol/L of LXA(4)); LXA(4) group (100 nmol/L of LXA(4)). All expriments were performed after cells treated for 12 and 24 hours respectively. Immunofluorescence was used to detect the expression of VIII foctor and nuclear translocation of nuclear factor-erythroid-2-related factor 2 (Nrf2); the mRNA expression of Nrf2, heme oxygenase 1 (HO-1) and reduced form of nicotinamide-adenine dinucleotide quinone oxidoreductase-1 (NQO1) were evaluated by reverse transcription-PCR. RESULTS: (1) The flavovirens fluorescence was observed in the cytoplasm under fluorescence microscope, which confirmed the existence of VIII factor which specifically expressed in endothelial cells, especially in HUVEC. (2) Immunofluorescent results showed that in control group, Nrf2 protein expressed in the cytosol rather than in the nucleus. In LPS group, the expression of Nrf2 protein obviously increased in the nucleus while decreased in the cytosol after 12 hours. However, after LPS treatment for 24 hours, Nrf2 expression reduced in the cytosol and nucleus. In co-treatment with LPS and LXA(4) group, the expression of Nrf2 protein was much higher than that in LPS group after 12 hours or 24 hours. Furthermore, Nrf2 protein also mostly expressed in the cytosol in LXA(4) group. (3) After stimulation for 12 hours, compared with control group, the gene expression of Nrf2 and HO-1 were significantly enhanced in LPS group (0.581 ± 0.019 and 0.081 ± 0.009, P < 0.05) and in LPS + LXA(4) group (0.692 ± 0.048 and 0.136 ± 0.018, P < 0.05), the level of NQO1 mRNA in LPS group and LPS + LXA(4) group were 0.381 ± 0.009 (P > 0.05) and 0.574 ± 0.034 (P < 0.05). After treatment for 24 hours, compared with control goup, the gene expressions of Nrf2 and NQO1 were down-regulated in LPS group (0.180 ± 0.017 and 0.472 ± 0.064, P < 0.05). But in LPS + LXA(4) group the expression of Nrf2 and NQO1 were upregulated (0.532 ± 0.051 and 0.830 ± 0.068, P < 0.05, compared with treatment for LPS group). The mRNA expressions of Nrf2, HO-1 and NQO1 were increased in LPS + LXA(4) group compared with LPS group (P < 0.05). In addition, there was no markedly difference in the expressions of Nrf2, HO-1 and NQO1 between control and LXA(4) group after 12 hours and 24 hours (P > 0.05). CONCLUSION: Through activating nuclear translocation of Nrf2 protein from cytoplasm, LXA(4) upregulates the Nrf2 downstream enzymes, such as NQO1 and HO-1 to protect HUVEC against the oxidative stress induced by LPS.


Assuntos
Células Endoteliais da Veia Umbilical Humana/metabolismo , Lipoxinas/farmacologia , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Células Cultivadas , Feminino , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Lipopolissacarídeos/antagonistas & inibidores , Lipoxinas/administração & dosagem , NAD(P)H Desidrogenase (Quinona)/genética , NAD(P)H Desidrogenase (Quinona)/metabolismo , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
10.
Pharmacology ; 84(1): 17-23, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19478549

RESUMO

Lipoxin A(4) (LXA(4)), a 'stop signal' for inflammation, is endogenously produced by eicosanoids, mainly via cell-to-cell interactions. At present, its influence on hypoxic angiogenesis, which is responsible for tumor growth and metastasis, has not been determined. Hypoxia regulates a variety of transcription factors including hypoxia-inducible factor (HIF)-1alpha, which plays a role in the expression of vascular endothelial growth factor (VEGF) and is considered a target for anti-angiogenic therapy. In this study, we utilized cobalt chloride (CoCl(2)) to mimic hypoxia in vitro. Data suggested that LXA(4) decreased the expression and nucleus translocation of HIF-1alpha in a dose-dependent manner in CoCl(2)-treated human umbilical vein endothelial cells (HUVEC). Furthermore, we confirmed that LXA(4) suppressed VEGF expression, tube formation and migration activity of HUVEC under hypoxia induced by CoCl(2). These results suggest that LXA(4) may have inhibitory effects on tumor angiogenesis through downregulation of the expression and nucleus translocation of HIF-1alpha. In summary, this study provides the first evidence for the anti-angiogenic role of LXA(4) on hypoxic human endothelial cells, which may have therapeutic value for cancer and other angiogenesis-associated diseases.


Assuntos
Inibidores da Angiogênese/farmacologia , Cobalto/farmacologia , Células Endoteliais/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Lipoxinas/farmacologia , Veias Umbilicais/citologia , Hipóxia Celular , Células Cultivadas , Células Endoteliais/citologia , Endotélio Vascular/citologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/metabolismo
11.
Zhonghua Fu Chan Ke Za Zhi ; 44(4): 281-4, 2009 Apr.
Artigo em Zh | MEDLINE | ID: mdl-19570467

RESUMO

OBJECTIVE: To investigate protective effects and mechanisms of lipoxinA(4) (LXA(4)) on human umbilical vein endothelial cells (HUVEC) under hypoxia in vitro. METHODS: The HUVEC culture were divided into groups as followed: added M199 culture medium as normal control groups, added CoCl2 to mimic hypoxia in vitro as hypoxia group and added different concentrations of LXA(4) (1, 10, 100 nmol/L) were added to the induced hypoxial HUVEC as agents intervention group. Morphological changes of HUVEC were observed by using inverted phase contrast microscope. The influence of LXA(4) on cell survival was investigated by methyl thiazolyl tetrazolium (MTT) assaying method after the treatment with different concentrations of LXA(4) and 100 nmol/L lipoxinA(4) according to different time (4, 8, 12 and 24 hours). The expression of von-willebrand factor (vWF) was detected by immunocytochemistry method. The changes of cytosolic Ca(2+) were measured by laser scanning confocal microscope. RESULTS: (1) Morphological changes:the cells under hypoxia lost its normal shapes and showed necrosis, while the cells cocultured with 100 nmol/L LXA(4) were normal appropriately. (2) Survival rate: the survival rates of HUVEC under hypoxia was (40.1 +/- 3.9)% and increased to (52.9 +/- 1.4)%, (64.1 +/- 3.3)%, (76.6 +/- 1.6)% respectively when added with LXA(4) with concentration of 1, 10, 100 nmol/L into culture medium. There was significant different survival rate when compared with that of hypoxia group. (3) The level of vWF: The expression of vWF was decreased with the increasing concentrations of LXA(4) added into culture medium, the gray values were 203.9 +/- 0.7 in 1 nmol/L, 204.6 +/- 0.9 in 10 nmol/L, 191.8 +/- 0.5 in 100 nmol/L respectively, which reached statistical difference in comparison with that of hypoxia groups (P < 0.05). (4) Confocal analysis: the intracellular free Ca(2+) concentrations of HUVEC were intensified with LXA(4) treatment. CONCLUSIONS: LXA(4) plays an important role in keeping the normal shape of HUVEC under hypoxia, can enhance survival of hypoxial HUVEC and decrease the level of vWF in cytoplasm. The protective mechanism might be via decreasing mitochondria Ca(2+) overload and increasing cytoplasm Ca(2+) by nucleus Ca(2+) transference.


Assuntos
Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Lipoxinas/farmacologia , Cálcio/metabolismo , Hipóxia Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cobalto/farmacologia , Colorimetria , Relação Dose-Resposta a Droga , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Imuno-Histoquímica , Lipoxinas/administração & dosagem , Fatores de Tempo , Fator de von Willebrand/metabolismo
12.
AJP Rep ; 9(3): e201-e208, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31281736

RESUMO

Aim This article determines the optimal time and dose of cadmium chloride (CdCl 2 ) injected to pregnant rat to establish experimental preeclampsia (PE) model. In addition, the therapeutic potential of BML-111, a lipoxin A4 analogue, in the CdCl 2 -induced PE model was also evaluated. Methods Peritoneal injection of two dose of CdCl 2 for successive 6 days was tested in the pregnant rats starting from various gestational days (GDs). During this process, the systolic blood pressure and the body weight of pregnant rats and neonatal rats were monitored. The pathological changes of the placenta and kidney were evaluated by hematoxylin and eosin staining. The phosphorylation of extracellular signal-regulated kinase 1/2 and signal transducer and activator of transcription 3 in the placentas was detected by Western blot, and the messenger ribonucleic acid expression of interleukin (IL)-6, tumor necrosis factor-α, and IL-10 in the placentas were detected by real-time polymerase chain reaction. BML-111 at the dose of 1 mg/kg/day was peritoneally injected into the rat after establishing the PE model to test its therapeutic potential. Results In the present study, we successfully established the PE model in pregnant rats by intraperitoneally injection of CdCl 2 at the dose of 0.125 mg/kg/day from GD 9 to 14. We recapitulated multiple features of clinical PE in CdCl 2 -induced rat, including high blood pressure, renal dysfunction, and inflammatory response in placenta. Furthermore, treatment with BML-111 significantly relieved multiple features in our PE rat model. Conclusions BML-111 has a potential therapeutic effect in pregnant rats with CdCl 2 -induced PE, which appears to be mediated through inhibition of inflammatory processes in the placenta.

13.
Am J Reprod Immunol ; 81(5): e13107, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30811719

RESUMO

PROBLEM: To test whether lipoxin A4 (LXA4) interferes with embryo implantation via suppression of epithelial-mesenchymal transition (EMT). METHOD OF STUDY: We developed a mouse model of LXA4 blocking embryo implantation and detected the indicators of EMT to confirm that LXA4 inhibits EMT might be a mechanism of interfering with the embryo implantation. We detected integrin-linked kinase (ILK), N-formylpeptide receptor 2 (FPR2), vascular endothelial growth factor, matrix metalloproteinases (MMPs), Akt, GSK3ß, NF-ĸB, twist, vimentin, fibronectin, and ß-catenin mRNA expression using reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time RT-PCR; localized protein expression using immunohistochemistry and Western blotting assay; MMPs activity assay by gelatin zymography; and the status of implantation in pregnant animals assessed by pontamine blue reaction test. RESULTS: Preimplantation administration of LXA4 resulted in implantation failure. LXA4 has a time- and dose-dependent effect on embryo implantation. Day 0.5 after fertilization is the most effective time to use LXA4 to block embryo implantation. (a) LXA4 reduced endometrial stroma edema; (b) LXA4 inhibited the activity of MMP9 and significantly upregulated the expression of ß-catenin, and downregulated the expression of vimentin, fibronectin, twist, NF-κB, Akt, and Gsk-3ß in the endometrium and TEV-1 cells; (c) LXA4 upregulated the expression of FPR2, and downregulated the expression of ILK; FPR2-overexpressing had an inhibitory effect on ILK in TEV-1 cells. CONCLUSION: LXA4 inhibits EMT which attenuates ILK action by enhancing FPR2; therefore, this might be a mechanism of interfering with embryo implantation.


Assuntos
Infertilidade Feminina/imunologia , Lipoxinas/metabolismo , Receptores de Formil Peptídeo/metabolismo , Receptores de Lipoxinas/metabolismo , Animais , Células Cultivadas , Implantação do Embrião , Transição Epitelial-Mesenquimal , Feminino , Humanos , Metaloproteinases da Matriz/genética , Metaloproteinases da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Modelos Animais , Gravidez , Receptores de Formil Peptídeo/genética , Receptores de Lipoxinas/genética , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
14.
Arch Biochem Biophys ; 478(1): 110-8, 2008 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-18652801

RESUMO

In electrically non-excitable cells, one major source of Ca(2+) influx is through the store-operated (or Ca(2+) release-activated Ca(2+)) channel by which the process of emptying the intracellular Ca(2+) stores results in the activation of Ca(2+) channels in the plasma membrane. Using both whole-cell patch-clamp and Ca(2+) imaging technique, we describe the electrophysiology mechanism underlying formyl-peptide receptor like 1 (FPRL1) linked to intracellular Ca(2+) mobilization. The FPRL1 agonists induced Ca(2+) release from the endoplasmic reticulum and subsequently evoked I(CRAC)-like currents displaying fast inactivation in K562 erythroleukemia cells which expresses FPRL1, but had almost no effect in K562 cells treated with FPRL1 RNA-interference and HEK293 cells which showed no FPRL1 expression. The currents were impaired after either complete store depletion by the sarco/endoplasmic reticulum Ca(2+)-ATPase inhibitor thapsigargin, or after inhibition of PLC by U73122. Our results present the first evidence that FPRL1 is a potent mediator in the activation of CRAC channels.


Assuntos
Canais de Cálcio/química , Cálcio/metabolismo , Regulação da Expressão Gênica , Receptores de Formil Peptídeo/metabolismo , Receptores de Lipoxinas/metabolismo , Anexinas/metabolismo , Canais de Cálcio/metabolismo , Linhagem Celular , Citosol/metabolismo , Humanos , Células K562 , Lipoxinas/metabolismo , Modelos Biológicos , Técnicas de Patch-Clamp , Sódio/metabolismo , Tapsigargina/farmacologia
15.
Zhonghua Fu Chan Ke Za Zhi ; 43(4): 266-8, 2008 Apr.
Artigo em Zh | MEDLINE | ID: mdl-18843966

RESUMO

OBJECTIVE: To investigate the clinical feature, treatment and prognosis of both the mother and the fetus with gestational diabetes insipidus. METHODS: A total of 7 cases of gestational diabetes insipidus collected in the First Affiliated Hospital of Wenzhou Medical College, Wenzhou Combination of Traditional Chinese Medicine with Western Medicine Hospital, and Zhejiang Taizhou Hospital from June 1993 to June 2006 were analyzed retrospectively. RESULTS: Seven cases symptoms all characterized by excessive thirst polydipsia and polyuria. The average 24 h urinary output was between 11 L to 13 L and manifested of hypobaricuria. After effective treatment (three cases were treated with 1-deamino-8-D-arginine vasopressin, another three patients were managed with hydrochlorothiazide, and the last one was cured with antisterone), seven patients with gestational diabetes insipidus did not have any severe consequences. Their symptoms of excessive thirst, polyuria, and polydypsia disappeared from 7 days to 3 months after parturition. Urinary volume returned to normal standard of 1000-2000 ml during 24 hours. Specific gravity of urine recovered normally between a range 1.015-1.025 and serum sodium recovered between 135-147 mmol/L. The average duration of illness was 52 days. Eight newborn infants survived. Two of them were sent to neonatal intensive care unit for treatment. One was because of premature delivery caused by antepartum eclampsia, and the other case was one of the twins who had hydronephrosis. The baby of the first case left hospital after 3 weeks' treatment. The latter one's symptom disappeared 2 weeks after delivery. No obvious symptom was discovered among all the babies through follow-up telephone calls 42 days after childbirth. CONCLUSION: Gestational diabetes insipidus is a rare endocrinopathy complicating pregnancy. This disorder is characterized by excessive thirst, polydypsia, polyuria, hypobaric urine and electrolyte disturbances usually manifesting in the third trimester of pregnancy or puerperium. This is a transient syndrome. The first treatment of choice in patients with gestational diabetes insipidus is 1-deamino-8-D-arginine vasopressin and the second-choice is hydrochlorothiazide. Early diagnosis and appropriate management of the disease may reduce the hazard for both the mother and the fetus during perinatal period.


Assuntos
Desamino Arginina Vasopressina/uso terapêutico , Diabetes Insípido/tratamento farmacológico , Diabetes Insípido/patologia , Hidroclorotiazida/uso terapêutico , Complicações na Gravidez/tratamento farmacológico , Complicações na Gravidez/patologia , Adulto , Diabetes Insípido/etiologia , Feminino , Humanos , Recém-Nascido , Poliúria/tratamento farmacológico , Poliúria/patologia , Gravidez , Complicações na Gravidez/etiologia , Resultado da Gravidez , Prognóstico , Estudos Retrospectivos , Sódio/sangue , Vasopressinas/sangue , Vasopressinas/metabolismo , Adulto Jovem
16.
Zhonghua Fu Chan Ke Za Zhi ; 43(5): 325-8, 2008 May.
Artigo em Zh | MEDLINE | ID: mdl-18953862

RESUMO

OBJECTIVE: To study the effect of lipoxins on the proliferation and secretion of peritoneal macrophages from patients with preeclampsia in vitro. METHODS: Peritoneal macrophages were obtained from 24 patients with preeclampsia (preeclampsia group) and 24 normal pregnant women (normal pregnant group) who were treated in the First Affiliated Hospital of Wenzhou Medical College from March to July 2007. Enzyme linked immunosorbent assay (ELISA) was used to detect the concentration of tumor necrosis factor-alpha (TNF-alpha) in the supernatant of macrophages which were pulsed with lipoxins at different concentrations (0, 10, 100 nmol/L) in both groups after 48 hours. Methyl thiazolyl tetrazolium (MMTT) assay was used to detect the inhibition rate of cell proliferation of macrophages which were pulsed with lipoxins at different concentrations (0, 10, 100 nmol/L) in both groups after 24 hours. RESULTS: (1) The concentration of TNF-alpha: the levels of TNF-alpha were (1867.5 +/- 47.3), (1836.9 +/- 4.5) and (1800.5 +/- 2.7) ng/L after treatment with different concentrations of lipoxins (0, 10, 100 nmol/L) in preeclampsia group vs normal pregnant group [(791.3 +/- 62.2), (789.4 +/- 2.3), (781.5 +/- 1.9) ng/L]. The levels of TNF-alpha in preeclampsia group were significantly higher than that in normal pregnant group (P < 0.05). Lipoxins significantly inhibited the concentration of TNF-alpha in a dose-dependent manner in preeclampsia group (P < 0.05), while it had no significant effect in normal pregnant group (P > 0.05). (2) Cell proliferation inhibition: Incubation with lipoxins produced a dose-dependent (0, 10, 100 nmol/L) inhibitory effect on proliferation in preeclampsia group, [ 14. +/-6. )% , (32. +/-3.6)%, ( 6. ++/-3. )% vs normal pregnant group [(16.8 +/- 6.9)%, (16.7 +/- 5.4)%, (15.9 +/- 2.1 )%]. The rate of cell proliferation in preeclampsia group was significantly higher than that in normal pregnant group. Lipoxins significantly inhibited this growth (P < 0.05) , while it had no significant effect in normal pregnant group (P > 0.05). CONCLUSION: Lipoxins can inhibit the proliferation of macrophage and secretion of TNF-alpha in preeclampsia in a dose-dependent manner. Lipoxins may be potentially useful in prevention and treatment of preeclampsia.


Assuntos
Proliferação de Células/efeitos dos fármacos , Lipoxinas/farmacologia , Macrófagos Peritoneais/metabolismo , Pré-Eclâmpsia/patologia , Fator de Necrose Tumoral alfa/metabolismo , Adulto , Células Cultivadas , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Lipoxinas/administração & dosagem , Macrófagos Peritoneais/efeitos dos fármacos , Pré-Eclâmpsia/imunologia , Pré-Eclâmpsia/metabolismo , Gravidez , Estudos Retrospectivos
17.
Placenta ; 62: 16-24, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29405962

RESUMO

INTRODUCTION: Preeclampsia is associated with the presence of pathogenic angiotensin-receptor-activating autoantibodies. Cadmium is an increasingly prevalent environmental pollutant that can mimic oestrogens, which may enhance immunoglobulin production. Progesterone exerts opposite effects to oestrogen. METHODS: We measured the levels of cadmium and progesterone in preeclamptic patients and controls. Pregnant rats exposed to cadmium (0.125 mg/kg body weight) from gestational day 9-12 were treated with/without progesterone (3 mg/kg) beginning from gestational day 9 to delivery. We analysed the main features of preeclampsia and circulating level of the angiotensin II type 1 receptor agonistic autoantibody. We also measured the expression of activation-induced cytosine deaminase in B cells. RESULTS: There were higher cadmium levels and lower progesterone levels in the blood of preeclamptic women than in the blood of those with a healthy pregnancy. Based on this finding, a rat model of preeclampsia was established by intraperitoneally administrating low-dose cadmium on gestational days 9-12. Rats were then treated with/without progesterone. Key features of preeclampsia, including hypertension, proteinuria and placental abnormalities, appeared in pregnant rats after cadmium injection and improved after treatment with progesterone. Cadmium increased immunoglobulin production, mainly angiotensin II type 1-receptor-agonistic autoantibodies, by increasing the expression of activation-induced cytosine deaminase in B cells; progesterone exerted an opposite effect. CONCLUSION: Cadmium induced immune abnormalities that may be a key pathogenic contributor to preeclampsia. Progesterone supplementation to correct hormonal imbalance may be a viable strategy for preeclampsia management.


Assuntos
Autoanticorpos/sangue , Cádmio/farmacologia , Hipertensão/tratamento farmacológico , Pré-Eclâmpsia/sangue , Progesterona/uso terapêutico , Receptor Tipo 1 de Angiotensina/imunologia , Adulto , Animais , Cádmio/sangue , Feminino , Humanos , Hipertensão/sangue , Imunoglobulinas/sangue , Gravidez , Progesterona/sangue , Progesterona/farmacologia , Ratos
18.
Zhonghua Fu Chan Ke Za Zhi ; 42(10): 662-5, 2007 Oct.
Artigo em Zh | MEDLINE | ID: mdl-18241539

RESUMO

OBJECTIVE: To explore the perinatal outcomes of women with pulmonary hypertension complicating congenital heart disease (CHD). METHODS: Clinical data of 45 cases of pregnant women with pulmonary hypertension complicating CHD from Apr 1995 to May 2007 were analyzed and they were divided into three groups: 29 cases of slight group [pulmonary hypertension of 30 mm Hg (1 mm Hg = 0.133 kPa) to 49 mm Hg], 8 cases of moderate group (pulmonary hypertension of 50 mm Hg to 79 mm Hg) and 8 cases of severe group (pulmonary hypertension equal to or higher than 80 mm Hg). The types of CHD, cardiac functional status (New York heart association, NYHA), gestational weeks of pregnancy termination, mode of delivery, pregnancy after CHD operation and outcomes of infants were compared between the groups. RESULTS: (1) The highest incidence of CHD were atrial septal defect and ventricular septal defect (58%, 26/45). The rate of pregnant women after CHD operation was 29% (13/45), they were mainly in slight group and their NYHA class were in I - II. (2) The occurrence rate of NYHA class III - IV was 7 /8 in severe group. The rate of NYHA class I - II was 6/8 in moderate group. The rate of NYHA class I - II was 97% (28/29) in slight group. (3) The rate of term delivery was 93% (27/29), preterm labor 3% (1/29), abortion 3% (1/29), and the birth weight was (3153 +/- 399) g on average in slight group. The rate of term delivery was 5/8, preterm labor occurred in 3 cases in moderate group. The rate of term delivery was 5/8, preterm labor occurred in 2 cases, and iatrogenic abortion in 1 case in severe group. The average birth weight between slight group and moderate or severe group had a significant difference. (4) Caesarean section rate was 78% (35/45) among all patients. The rate of cesarean section delivery was 76% (22/29) in slight group, 6/8 in moderate group, and 7/8 in severe group. (5) The rate of pregnant women who had portent heart failure or heart failure was 24% (11/45), overall maternal mortality was 4% (2/45). CONCLUSIONS: The higher the pulmonary hypertension, the worse the outcome of the mother and fetus; The pregnant women with good heart function after cardiac operation would have a good perinatal outcome. Cesarean section is more suitable for those women.


Assuntos
Cardiopatias Congênitas/patologia , Hipertensão Pulmonar/patologia , Complicações Cardiovasculares na Gravidez/patologia , Resultado da Gravidez , Aborto Induzido/métodos , Adulto , Cesárea , Feminino , Idade Gestacional , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/fisiopatologia , Humanos , Hipertensão Pulmonar/complicações , Hipertensão Pulmonar/fisiopatologia , Recém-Nascido , Gravidez , Complicações Cardiovasculares na Gravidez/fisiopatologia , Estudos Retrospectivos , Índice de Gravidade de Doença
19.
Mater Sci Eng C Mater Biol Appl ; 70(Pt 1): 763-771, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27770953

RESUMO

Monodispersed SPIONs (superparamagnetic iron oxide nanoparticles) co-coated with PEG and PEI polymers were prepared by an improved polyol method. To accomplish cancer-specific targeting properties, FA (folic acid) was then modified on the SPIONs via EDC/NHS method (FA-SPIONs). Doxorubicin (DOX) as an example anticancer drug was loaded within FA-SPIONs (DOX@FA-SPIONs), the DOX release rate of DOX@FA-SPIONs was much high in low pH PBS. The SPIONs, FA-SPIONs and DOX@FA-SPIONs with mean hydrodynamic diameters of 23, 40 and 67nm, respectively, performed excellent colloidal stability in PBS. Confocal laser scanning microscope (CLSM) study implicates that the DOX@FA-SPIONs target MCF-7 cells efficiently through the FA receptor-mediated endocytosis. DOX@FA-SPIONs were tested in nude mice with xenograft MCF-7 breast tumor though tail intravenous injection and were found inhibiting tumor growth more efficiently. The application of a magnetic field (MF) greatly improved the growth inhibiting efficiencies of DOX@FA-SPIONs on MCF-7 cells in vitro and on xenograft MCF-7 breast tumor of nude mice in vivo. The aggregation of SPIONs in tumor was monitored by magnetic resonance imaging (MRI) as the DOX@FA-SPIONs exhibited high r2 relaxivity (81.77mM-1S-1). Histology on liver, Lung, kidney and heart in mice showed no significant toxicity of DOX@FA-SPIONs on mice organs after 35-day treatment. The FA-SPIONs are a high efficient drug delivery nanoplatform for advanced cancer theranostics.


Assuntos
Dextranos/química , Sistemas de Liberação de Medicamentos , Ácido Fólico/química , Imageamento por Ressonância Magnética , Nanopartículas de Magnetita/química , Nanopartículas/química , Neoplasias/diagnóstico , Neoplasias/terapia , Nanomedicina Teranóstica/métodos , Animais , Antineoplásicos/farmacologia , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/farmacologia , Feminino , Humanos , Hidrodinâmica , Concentração de Íons de Hidrogênio , Células MCF-7 , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanopartículas/ultraestrutura , Tamanho da Partícula , Propriedades de Superfície , Distribuição Tecidual/efeitos dos fármacos
20.
Mater Sci Eng C Mater Biol Appl ; 81: 400-406, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28887991

RESUMO

The subcellular distributions of nanoparticles in the brain are important for their biological application. We synthesized and characterized the superparamagnetic iron oxide nanoparticles (SPIONs) modified with poly (ethylene glycol) (PEG) and polyethylenimine (PEI) (PEG/PEI-SPIONs), and with dimyristoylphosphatidylcholine (DMPC) (DMPC-SPIONs). The nanoparticles were unilaterally injected into the left substantia nigra of rat brains. The distributions of the nanoparticles in the left brains of the rats were examined by ICP-OES (inductively coupled plasma optical emission spectrometer) and TEM (transmission electron microscopy) at 24h after the injection. Iron was found in the olfactory bulb, temporal lobe, frontal cortex, thalamus and brain stem at 24h after the injection of DMPC-SPIONs and PEG/PEI-SPIONs. In the rat substantia nigra, most DMPC-SPIONs were distributed in and on the myelin sheath around axons or on cell membranes, some were in cells. As a comparison, less iron was found in the rat brains at 24h after the injection of PEG/PEI-SPIONs. Our experiments suggest DMPC modification on SPIONs be a safe and effective method for increasing SPIONs distribution on the cell membranes. This work is encouraging for further study on using DMPC-SPIONs for efficient drug delivery or for deep brain stimulation of neurons in a magnetic field.


Assuntos
Nanopartículas de Magnetita , Substância Negra , Animais , Dimiristoilfosfatidilcolina , Nanopartículas Metálicas , Polietilenoglicóis , Ratos
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