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1.
Environ Res ; 243: 117748, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38036205

RESUMO

The mpox epidemic had spread worldwide and become an epidemic of international concern. Before the emergence of targeted vaccines and specific drugs, it is necessary to numerically simulate and predict the epidemic. In order to better understand and grasp its transmission situation, and take some countermeasures accordingly when necessary, we predicted and simulated mpox transmission, vaccination and control scenarios using model developed for COVID-19 predictions. The results show that the prediction model can also achieve good results in predicting the mpox epidemic based on modified SEIR model. The total number of people infected with mpox on Dec 31, 2022 reached 83878, while the prediction of the model was 96456 with a relative error of 15%. The United States, Brazil, Spain, France, the United Kingdom and Germany are six countries with serve mpox epidemic. The predictions of their epidemic are 30543, 11191, 7447, 5945, 5606 and 4291 cases respectively, with an average relative error of 20%. If 30% of the population is vaccinated using a vaccine that is 78% effective, the number of infected people will drop by 29%. This shows that the system can be practically applied to the prediction of mpox epidemic and provide corresponding decision-making reference.


Assuntos
COVID-19 , Epidemias , Mpox , Humanos , Brasil , COVID-19/epidemiologia , França/epidemiologia
2.
Photochem Photobiol ; 99(2): 787-792, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-35857390

RESUMO

As a tumor photodiagnostic agent, 5-aminolevulinic acid (ALA) is metabolized in the heme biosynthesis pathway to produce protoporphyrin IX (PpIX) with fluorescence. ALA-PpIX fluorescence was evaluated in human renal cell carcinoma (RCC) cell lines and non-tumor HK-2 cell lines. We found that extracellular PpIX level was correlated with ABCG2 activity, illustrating its importance as a PpIX efflux transporter. Extracellular PpIX was also related to the Km of ferrochelatase (FECH) that chelates PpIX with ferrous iron to form heme. The Vmax of FECH was higher in all RCC cell lines tested than in the HK-2 cell line. TCGA dataset analysis indicates a positive correlation between FECH expression and RCC patient survival. These findings suggest FECH as an important biomarker in RCC. Effects of iron chelator deferoxamine (DFO) on the enhancement of PpIX fluorescence were assessed. DFO increased intracellular PpIX in both tumor and non-tumor cells, resulting in no gain in tumor/non-tumor fluorescence ratios. DFO appeared to increase ALA-PpIX more at 1-h than at 4-h treatment. There was an inverse correlation between ALA-PpIX fluorescence and the enhancement effect of DFO. These results suggest that enhancement of ALA-PpIX by DFO may be limited by the availability of ferrous iron in mitochondria following ALA administration.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Fotoquimioterapia , Humanos , Ácido Aminolevulínico/farmacologia , Ácido Aminolevulínico/metabolismo , Desferroxamina/farmacologia , Carcinoma de Células Renais/tratamento farmacológico , Fluorescência , Protoporfirinas/farmacologia , Protoporfirinas/metabolismo , Ferro , Heme , Neoplasias Renais/tratamento farmacológico , Quelantes de Ferro/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Linhagem Celular Tumoral , Fotoquimioterapia/métodos
3.
BMC Ecol Evol ; 22(1): 63, 2022 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-35550012

RESUMO

BACKGROUND: Social wasps Polistes, Ropalidia, and Parapolybia, belonging to the subfamily Polistinae, have obviously different distribution patterns, yet the factors leading to this difference remain unknown. RESULTS: The 17 newly sequenced mitogenomes of Polistes, Ropalidia, and Parapolybia contain 37 genes, and there are obvious differences among the compositions of the three genera. The monophyly of the genus Polistes and a monophyletic Ropalidiini: (Ropalidia + Parapolybia) are concordant with previous morphological analysis of the subfamily Polistinae. Our inferred divergence time demonstrates Polistes (at around 69 Ma) was diverged earlier than Ropalidia and Parapolybia (at around 61 Ma). The rearrangement of both trnY and trnL1 are shared by all the Polistinae. In addition, the unique rearrangement of TDRL derived at 69 Ma is detected in Polistes, and Ropalidia contains a Reversal which may derive at 61 Ma. Hereafter, the possibility is elaborated that Polistes originated in Aisa and then dispersed from Africa to South America, and Polistes and Ropalidia spread from Southeast Asia to Australia. At last, continental drift and Quaternary Ice Ages are inferred to be two main limiting factors in the current distributions of the three genera. CONCLUSIONS: Obvious differences occur in the mitochondrial composition of Polistes, Ropalidia, and Parapolybia. According to the reconstructed time-calibrated framework, it is inquired that the continental drifts and the climate are mainly diffusion limiting factors of the three genera.


Assuntos
Vespas , África , Animais , Austrália , América do Sul , Vespas/genética
4.
Ann Hepatol ; 21: 100279, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33157267

RESUMO

INTRODUCTION: Coronavirus disease 2019 (COVID-19) has brought great challenges to global public health. However, a comprehensive analysis of the relationship between liver biochemical parameters and COVID-19 mortality is quite limited. METHODS: We searched the following electronic databases: PubMed, Embase, Cochrane Library, Web of Science, Scopus, Wanfang and China National Knowledge Infrastructure database until May 5, 2020. STATA software was used for the statistical analyses. RESULTS: A total of 25 studies involving 5971 COVID-19 patients were included in our analysis. Compared with non-survivors, survivors had lower levels of aspartate aminotransferase (AST) (weighted mean difference [WMD]=-16.71U/L, 95%CI=[-21.03,-12.40], P<0.001), alanine transaminase (ALT) (WMD=-5.20U/L, 95%CI=[-8.00,-2.41], P<0.001), total bilirubin (TBIL) (WMD=4.40µmol/L, 95%CI=[-5.11,-3.70], P<0.001) and lactic dehydrogenase (LDH) (WMD=-252.44U/L, 95%CI=[-289.57,-215.30], P<0.001), and higher albumin (ALB) level (WMD=4.47g/L, 95%CI=[3.47,5.47], P<0.001). Besides, survivors had lower proportions of these abnormally increased parameters (AST: OR=0.25, 95%CI=[0.15,0.41], P<0.001; ALT: OR=0.49, 95%CI=[0.37,0.64], P<0.001; TBIL: (OR=0.20, 95%CI=[0.12,0.34], P<0.001; LDH, OR=0.09, 95%CI=[0.06,0.14], P<0.001), and lower proportion of abnormally decreased ALB (OR=0.16, 95%CI=[0.07,0.38], P<0.001). Meta-analysis based on standard mean difference and sensitivity analysis did not change the conclusions. Egger test did not detect the presence of publication bias. CONCLUSIONS: Liver biochemical parameters were strongly correlated with COVID-19 mortality. Measurement of these liver biochemical parameters might assist clinicians to evaluate the prognosis of COVID-19.


Assuntos
Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , COVID-19/mortalidade , Prognóstico , SARS-CoV-2 , Biomarcadores/sangue , COVID-19/enzimologia , Saúde Global , Humanos , Pandemias , Taxa de Sobrevida/tendências
5.
Photochem Photobiol ; 96(2): 358-364, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31769520

RESUMO

Photodynamic therapy (PDT) with photosensitizer verteporfin is a clinically approved vascular disrupting modality that is currently in clinical trial for cancer treatment. In this study, we evaluated PDT in combination with either mTORC1 inhibitor rapamycin or mTORC1/C2 dual inhibitor AZD2014 for therapeutic enhancement in SVEC endothelial cells. Verteporfin-PDT alone induced cell apoptosis by activating the intrinsic apoptotic pathway. However, it increased the expression of anti-apoptotic protein MCL-1 and the phosphorylation of S6, a downstream molecule of mTOR signaling. In contrast, mTOR inhibitors rapamycin and AZD2014 did not induce apoptosis in SVEC cells. They suppressed MCL-1 expression and S6 phosphorylation and imposed a potent inhibition on cell proliferation. PDT in combination with mTOR inhibitors activated the intrinsic apoptotic pathway and resulted in increased apoptosis. Combination treatments also led to sustained inhibition of cell proliferation. Although AZD2014 was more effective for cell growth inhibition and PDT enhancement than rapamycin at the higher concentrations examined in the study, both inhibitors effectively enhanced PDT response, suggesting that inhibition of mTORC1 is crucial for PDT enhancement. Our results indicate that mTOR inhibitors mechanistically cooperate with PDT for enhanced cell death and sustained growth inhibition, supporting a combination approach for therapeutic enhancement.


Assuntos
Apoptose/efeitos dos fármacos , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/uso terapêutico , Serina-Treonina Quinases TOR/antagonistas & inibidores , Verteporfina/uso terapêutico , Animais , Benzamidas/farmacologia , Linhagem Celular Transformada , Humanos , Camundongos , Morfolinas/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Pirimidinas/farmacologia , Sirolimo/farmacologia , Verteporfina/farmacologia
6.
Clin Transl Oncol ; 22(3): 401-410, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31172445

RESUMO

PURPOSE: Hepatitis B core antibody (HBcAb) positivity is regarded as a sensitive marker for occult and prior hepatitis B virus (HBV) infection. However, the prognosis of patients with HBcAb-positive in non-B, non-C hepatocellular carcinoma (NBNC-HCC) remains unclear. The study aimed to compare the clinicopathological characteristics of patients with HBcAb-positive NBNC-HCC to those with overt HBV (hepatitis B surface antigen positive) HCC. METHODS: 306 HCC patients underwent hepatectomy were divided into two groups: an overt HBV-HCC group and HBcAb-positive NBNC-HCC group. Then patients were analyzed using propensity score matching (PSM) to reduce selection bias. Clinicopathological characteristics and survival outcomes were compared between the two groups. Univariate and multivariate analysis for risk factors were also evaluated. RESULTS: HBcAb-positive NBNC-HCC group showed comparable survival outcomes to the overt HBV-HCC group (3-year overall survival rates 66% vs 62%, 69% vs 53%; 3-year recurrence-free survival rates 49% vs 40%, 47% vs 37%; P > 0.05) before and after PSM. Patients with HBcAb-positive NBNC-HCC were older, had more complications, higher proportions of vascular invasion, and larger tumor sizes but lower proportions of cirrhosis, elevated alanine aminotransferase and prothrombin time. CONCLUSIONS: HBcAb-positive NBNC-HCC group had more advanced tumors, but their prognosis was relatively comparable to that of the other group. Therefore, we believe that screening is also necessary in HBcAb-positive patients for early detection of HCC, especially in the elderly.


Assuntos
Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/virologia , Vírus da Hepatite B/isolamento & purificação , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/virologia , Adulto , Idoso , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/cirurgia , Feminino , Hepatectomia , Hepatite B/complicações , Anticorpos Anti-Hepatite B/sangue , Antígenos do Núcleo do Vírus da Hepatite B/imunologia , Antígenos de Superfície da Hepatite B/sangue , Vírus da Hepatite B/imunologia , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Prognóstico , Pontuação de Propensão , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida , Resultado do Tratamento
7.
Photochem Photobiol ; 95(4): 1052-1059, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30767226

RESUMO

Aminolevulinic acid (ALA) is a prodrug that is metabolized in the heme biosynthesis pathway to produce protoporphyrin IX (PpIX) for tumor fluorescence detection and photodynamic therapy (PDT). The iron chelator deferoxamine (DFO) has been widely used to enhance PpIX accumulation by inhibiting the iron-dependent bioconversion of PpIX to heme, a reaction catalyzed by ferrochelatase (FECH). Tumor response to DFO treatment is known to be highly variable, and some tumors even show no response. Given the fact that tumors often exhibit reduced FECH expression/enzymatic activity, we examined how reducing FECH level affected the DFO enhancement effect. Our results showed that reducing FECH level by silencing FECH in SkBr3 breast cancer cells completely abrogated the enhancement effect of DFO. Although DFO enhanced ALA-PpIX fluorescence and PDT response in SkBr3 vector control cells, it caused a similar increase in MCF10A breast epithelial cells, resulting in no net gain in the selectivity toward tumor cells. We also found that DFO treatment induced less increase in ALA-PpIX fluorescence in tumor cells with lower FECH activity (MDA-MB-231, Hs 578T) than in tumor cells with higher FECH activity (MDA-MB-453). Our study demonstrates that FECH activity is an important determinant of tumor response to DFO treatment.


Assuntos
Ácido Aminolevulínico/farmacologia , Desferroxamina/farmacologia , Ferroquelatase/metabolismo , Fármacos Fotossensibilizantes/farmacologia , Protoporfirinas/farmacologia , Ácido Aminolevulínico/administração & dosagem , Neoplasias da Mama , Linhagem Celular Tumoral , Células Epiteliais , Feminino , Ferroquelatase/genética , Inativação Gênica , Humanos , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/administração & dosagem , Protoporfirinas/administração & dosagem , Sideróforos/farmacologia
8.
Hepatology ; 67(3): 1056-1070, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29059701

RESUMO

The role and regulators of extracellular vesicle (EV) secretion in hepatic ischemia/reperfusion (IR) injury have not been defined. Rab27a is a guanosine triphosphatase known to control EV release. Interferon regulatory factor 1 (IRF-1) is a transcription factor that plays an important role in liver IR and regulates certain guanosine triphosphatases. However, the relationships among IRF-1, Rab27a, and EV secretion are largely unknown. Here, we show induction of IRF-1 and Rab27a both in vitro in hypoxic hepatocytes and in vivo in warm IR and orthotopic liver transplantation livers. Interferon γ stimulation, IRF-1 transduction, or IR promoted Rab27a expression and EV secretion. Meanwhile, silencing of IRF-1 decreased Rab27a expression and EV secretion. Rab27a silencing decreased EV secretion and liver IR injury. Ten putative IRF-1 binding motifs in the 1,692-bp Rab27a promoter region were identified. Chromatin immunoprecipitation and electrophoretic mobility shift assay verified five functional IRF-1 binding motifs, which were confirmed by a Rab27a promoter luciferase assay. IR-induced EVs contained higher oxidized phospholipids (OxPL). OxPLs on the EV surface activated neutrophils through the toll-like receptor 4 pathway. OxPL-neutralizing E06 antibody blocked the effect of EVs and decreased liver IR injury. CONCLUSION: These findings provide a novel mechanism by which IRF-1 regulates Rab27a transcription and EV secretion, leading to OxPL activation of neutrophils and subsequent hepatic IR injury. (Hepatology 2018;67:1056-1070).


Assuntos
Vesículas Extracelulares/metabolismo , Fator Regulador 1 de Interferon/metabolismo , Fígado/patologia , Traumatismo por Reperfusão/metabolismo , Proteínas rab27 de Ligação ao GTP/metabolismo , Animais , Técnicas de Cultura de Células , Regulação da Expressão Gênica , Hepatócitos/metabolismo , Humanos , Fígado/metabolismo , Transplante de Fígado , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
9.
J Virol ; 91(3)2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-27852852

RESUMO

The alphaviruses Venezuelan equine encephalitis virus (VEEV), eastern equine encephalitis virus (EEEV), and western equine encephalitis virus (WEEV) are arthropod-borne positive-strand RNA viruses that are capable of causing acute and fatal encephalitis in many mammals, including humans. VEEV was weaponized during the Cold War and is recognized as a select agent. Currently, there are no FDA-approved vaccines or therapeutics for these viruses. The spread of VEEV and other members of this family due to climate change-mediated vector range expansion underscores the need for research aimed at developing medical countermeasures. These viruses utilize programmed -1 ribosomal frameshifting (-1 PRF) to synthesize the viral trans-frame (TF) protein, which has previously been shown to be important for neuropathogenesis in the related Sindbis virus. Here, the alphavirus -1 PRF signals were characterized, revealing novel -1 PRF stimulatory structures. -1 PRF attenuation mildly affected the kinetics of VEEV accumulation in cultured cells but strongly inhibited its pathogenesis in an aerosol infection mouse model. Importantly, the decreased viral titers in the brains of mice infected with the mutant virus suggest that the alphavirus TF protein is important for passage through the blood-brain barrier and/or for neuroinvasiveness. These findings suggest a novel approach to the development of safe and effective live attenuated vaccines directed against VEEV and perhaps other closely related -1 PRF-utilizing viruses. IMPORTANCE: Venezuelan equine encephalitis virus (VEEV) is a select agent that has been weaponized. This arthropod-borne positive-strand RNA virus causes acute and fatal encephalitis in many mammals, including humans. There is no vaccine or other approved therapeutic. VEEV and related alphaviruses utilize programmed -1 ribosomal frameshifting (-1 PRF) to synthesize the viral trans-frame (TF) protein, which is important for neuropathogenesis. -1 PRF attenuation strongly inhibited VEEV pathogenesis in mice, and viral replication analyses suggest that the TF protein is critical for neurological disease. These findings suggest a new approach to the development of safe and effective live attenuated vaccines directed against VEEV and other related viruses.


Assuntos
Vírus da Encefalite Equina Venezuelana/genética , Encefalomielite Equina Venezuelana/virologia , Mudança da Fase de Leitura do Gene Ribossômico , Animais , Linhagem Celular , Feminino , Genoma Viral , Cavalos , Humanos , Conformação de Ácido Nucleico , Fases de Leitura Aberta , RNA Mensageiro/química , RNA Mensageiro/genética , RNA Viral , Replicação Viral
10.
Photochem Photobiol ; 91(4): 923-30, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25809721

RESUMO

Aminolevulinic acid (ALA)-mediated protoporphyrin IX (PpIX) production is being explored for tumor fluorescence imaging and photodynamic therapy (PDT). As a prodrug, ALA is converted in heme biosynthesis pathway to PpIX with fluorescent and photosensitizing properties. To better understand the role of heme biosynthesis enzymes in ALA-mediated PpIX fluorescence and PDT efficacy, we used lentiviral shRNA to silence the expression of porphobilinogen synthase (PBGS), porphobilinogen deaminase (PBGD) and ferrochelatase (FECH) in SkBr3 human breast cancer cells. PBGS and PBGD are the first two cytosolic enzymes involved in PpIX biosynthesis, and FECH is the enzyme responsible for converting PpIX to heme. PpIX fluorescence was examined by flow cytometry and confocal fluorescence microscopy. Cytotoxicity was assessed after ALA-mediated PDT. Silencing PBGS or PBGD significantly reduced ALA-stimulated PpIX fluorescence, whereas silencing FECH elevated basal and ALA-stimulated PpIX fluorescence. However, compared with vector control cells, the ratio of ALA-stimulated fluorescence to basal fluorescence without ALA was significantly reduced in all knockdown cell lines. PBGS or PBGD knockdown cells exhibited significant resistance to ALA-PDT, while increased sensitivity to ALA-PDT was found in FECH knockdown cells. These results demonstrate the importance of PBGS, PBGD and FECH in ALA-mediated PpIX fluorescence and PDT efficacy.


Assuntos
Ácido Aminolevulínico/metabolismo , Inativação Gênica , Heme/biossíntese , Fotoquimioterapia , Protoporfirinas/metabolismo , Linhagem Celular Tumoral , Humanos
11.
Photochem Photobiol Sci ; 13(2): 261-5, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24178437

RESUMO

Irradiation of (2R,4R)-(-)- and (2S,4S)-(+)-2,4-pentanediyl-bis-2-naphthoates (1R and 1S, respectively) in organic solutions exclusively results in cubane-like anti(HH) photodimers in 100% yield. Asymmetric induction with 100% diastereometric excess (de) has been achieved and the absolute configuration of the yielded diastereomers has been established. Moreover, irradiation of (2R,4S)-2,4-pentanediyl-bis-2-naphthoate (1M) gives cubane-like syn(HH) photodimers in 100% yield.

12.
Int. j. morphol ; 30(4): 1532-1537, dic. 2012. ilus
Artigo em Inglês | LILACS | ID: lil-670176

RESUMO

In order to explore the change rule of myoblast stem cells (satellite cells, SCs) in the denervated and re-innervated muscle and to investigate the cellular mechanism of the morphological and functional changes of the muscle, denervated muscle atrophy and nerve regeneration models were established in one-month-old rats. Postoperative indexes such as muscle wet weight, cell section areas, content of collagen fibers and DNA, electrophysiology, numbers of SCs in the triceps muscle of calf were dynamically tested. After denervation, the muscle wet weight and cell area reduced rapidly, and the collagen fiber content increased slowly. The number of SCs increased at first, and then declined suddenly two months later. From 4 to 5 weeks after re-neuralization, muscle action potentials could be evoked, but the best innervation effect was found in the groups, which received re-neuralization at 2 months and 3 months after denervation. Denervation causes a progressive progress of muscle atrophy. SCs proliferate within 3 months after denervation, and then atrophy becomes irreversible from 4 months. At 4 or 5 weeks after re-neuralization, muscle action potentials can be evoked. Re-neuralization at 2 months and 3 months after denervation can achieve a good effect on the functional recovery of the atrophic muscle.


Con el fin de explorar la regla de cambio de las células precursoras mioblásticas (células satélite, CSs) en el músculo denervado y re-inervado e investigar el mecanismo celular de los cambios morfológicos y funcionales del músculo, se establecieron, en ratas de un mes de edad, modelos de atrofia del músculo denervado y regeneración del nervio. Fueron examinados de manera dinámica índices postoperatorios tales como, el peso húmedo del músculo, áreas celulares de la sección, contenido de fibras de colágeno y ADN, electrofisiología, número de CSs en el músculo tríceps de las crías. Luego de la denervación, el peso del músculo húmedo y el área celular se redujeron rápidamente, mientras que el contenido de fibras colágenas aumentó lentamente. El número de CSs aumentó al inicio, pero más tarde, a los dos meses, disminuyó repentinamente. Entre las 4 a 5 semanas después de la reneuralización, los potenciales de acción muscular pudieron ser evocados, pero el mejor efecto de inervación se encontró en los grupos que recibieron reneuralización a los 2 y 3 meses después de la denervación. La denervación causó un avance progresivo de la atrofia muscular. Las CSs proliferaron dentro de los primeros 3 meses post-denervación, y luego de los 4 meses la atrofia fue irreversible. A las 4 o 5 semanas después de la reneuralizacón, los potenciales de acción muscular pueden ser evocados. La reneuralización a los 2 y 3 meses después de la denervación puede lograr un buen efecto en la recuperación funcional del músculo atrófico.


Assuntos
Animais , Ratos , Músculo Esquelético/citologia , Músculo Esquelético/inervação , Células Satélites de Músculo Esquelético , Regeneração , Células-Tronco , Atrofia Muscular , Denervação Muscular
13.
Arq Neuropsiquiatr ; 69(1): 105-11, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21359432

RESUMO

OBJECTIVE: Metallothionein 3 (MT-3) has been shown to protect against apoptotic neuronal death in the brains of patients with Alzheimer's disease. Zinc is a potent inhibitor of caspase-3 and its deficiency was found to promote apoptosis. Here, we measured the zinc and copper content in the brains of senescence-accelerated mouse/PRONE8 (SAMP8) and sought to investigate the effect of MT-3 on the apoptosis of neurons in the hippocampal CA1 region of these mice. METHOD: The zinc and copper content in the brain samples of SAMP8 and normal control SAMR1 mice were determined using an atomic absorption spectrophotometer. The mice were administered intraperitoneally for four weeks with MT-3 or MT1 and thereafter apoptosis was measured using the TUNEL method and the expression of anti-apoptotic protein Bcl-2 and proapoptotic protein Bax was examined by immunohistochemistry. RESULTS: Compared with that in SMAR1 mice, the content of zinc in the brains of SAMP8 mice was significantly reduced (P<0.05). Moreover, significant levels of apoptosis of neurons were observed in the hippocampus of SAMP8 mice, which, compared with those in SMAR1 mice, also showed significantly lower levels of Bcl-2 and higher levels of Bax (P<0.05). MT-3 increased zinc concentration in the hippocampus of SAMP8 mice and also significantly decreased apoptosis in these neurons dose-dependently and increased the levels of Bcl-2 and decreased the levels of Bax. CONCLUSION: MT-3 could attenuate apoptotic neuron death in the hippocampus of SAMP8, suggesting that the protein may lessen the development of neurodegeneration.


Assuntos
Apoptose/efeitos dos fármacos , Inibidores do Crescimento/farmacologia , Hipocampo/efeitos dos fármacos , Proteínas do Tecido Nervoso/farmacologia , Neurônios/efeitos dos fármacos , Envelhecimento , Animais , Química Encefálica , Caspase 3/deficiência , Inibidores de Caspase , Cobre/análise , Hipocampo/metabolismo , Hipocampo/patologia , Masculino , Metalotioneína/farmacologia , Metalotioneína 3 , Camundongos , Neurônios/metabolismo , Neurônios/patologia , Proteínas Proto-Oncogênicas c-bcl-2/análise , Especificidade da Espécie , Zinco/análise , Zinco/deficiência , Proteína X Associada a bcl-2/análise
14.
Arq. neuropsiquiatr ; Arq. neuropsiquiatr;69(1): 105-111, Feb. 2011. ilus, tab
Artigo em Inglês | LILACS | ID: lil-598355

RESUMO

OBJECTIVE: Metallothionein 3 (MT-3) has been shown to protect against apoptotic neuronal death in the brains of patients with Alzheimer's disease. Zinc is a potent inhibitor of caspase-3 and its deficiency was found to promote apoptosis. Here, we measured the zinc and copper content in the brains of senescence-accelerated mouse/PRONE8 (SAMP8) and sought to investigate the effect of MT-3 on the apoptosis of neurons in the hippocampal CA1 region of these mice. METHOD: The zinc and copper content in the brain samples of SAMP8 and normal control SAMR1 mice were determined using an atomic absorption spectrophotometer. The mice were administered intraperitoneally for four weeks with MT-3 or MT1 and thereafter apoptosis was measured using the TUNEL method and the expression of anti-apoptotic protein Bcl-2 and proapoptotic protein Bax was examined by immunohistochemistry. RESULTS: Compared with that in SMAR1 mice, the content of zinc in the brains of SAMP8 mice was significantly reduced (P<0.05). Moreover, significant levels of apoptosis of neurons were observed in the hippocampus of SAMP8 mice, which, compared with those in SMAR1 mice, also showed significantly lower levels of Bcl-2 and higher levels of Bax (P<0.05). MT-3 increased zinc concentration in the hippocampus of SAMP8 mice and also significantly decreased apoptosis in these neurons dose-dependently and increased the levels of Bcl-2 and decreased the levels of Bax. CONCLUSION: MT-3 could attenuate apoptotic neuron death in the hippocampus of SAMP8, suggesting that the protein may lessen the development of neurodegeneration.


OBJETIVO: Metalotioneína 3 (MT-3) tem mostrado proteção contra a apoptose neuronal em cérebros de pacientes com doença de Alzheimer. Zinco é um potente inibidor da caspase-3, e sua deficiência pode promover a apoptose. No presente trabalho, foram dosados os níveis de zinco e cobre nos cérebros de camundongos PRONE8 com envelhecimento acelerado (SAMP8), visando investigar o efeito da MT-3 na apoptse dos neurônios da região hipocampal CA1 destes camundongos. MÉTODO: Os níveis de zinco e cobre em amostras cerebrais de camundongos SAMP8 e de controles normais SAMR1 foram determinados por absorção atômica em espectrofotometria. Foram administradas MT-3 ou MT-1 intraperitoneais durante quatro semanas, sendo em seguida avaliada a apoptose pelo método TUNEL , enquanto a expressão da proteína anti-apoptótica Bcl-2 e a proteína pró-apoptótica Bax foram avaliadas por imunohistoquímica. RESULTADOS: Em comparação aos camundongos SMAR1, o nível de zinco nas amostras cerebrais dos camundongos SAMP8 estava significativamente diminuído (P<0.05). Além disto, níveis significativos de apoptose foram observados no hipocampo dos camundongos SAMP8, o que, em comparação com os níveis em camundongos SMAR1, também mostrava níveis significativamente mais baixos de Bcl-2 e níveis mais altos de Bax (P<0.05). MT-3 aumentou a concentração de zinco no hipocampo dos camundongos SAMP8, além de diminuir significativamente a apoptose destes neurônios, de uma forma dose-dependente, ao mesmo tempo que aumentou níveis de Bcl-2 e diminuiu níveis de Bax. CONCLUSÃO: MT-3 pode atenuar a morte neuronal apoptótica no hipocampo de SAMP8, o que sugere que esta proteína possa diminuir a neurodegeneração.


Assuntos
Animais , Masculino , Camundongos , Apoptose/efeitos dos fármacos , Inibidores do Crescimento/farmacologia , Hipocampo/efeitos dos fármacos , Proteínas do Tecido Nervoso/farmacologia , Neurônios/efeitos dos fármacos , Envelhecimento , Química Encefálica , /antagonistas & inibidores , /deficiência , Cobre/análise , Hipocampo/metabolismo , Hipocampo/patologia , Metalotioneína/farmacologia , Neurônios/metabolismo , Neurônios/patologia , /análise , Especificidade da Espécie , Zinco/análise , Zinco/deficiência , /análise
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