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Objective: To investigate the polymorphism of BIN1 and ApoE genes in amnestic mild cognitive impairment (aMCI) patients in Tujia minority area of Enshi, Hubei. Methods: A total of 107 patients with aMCI (aMCI group) and 150 healthy people (healthy control group) during the same period were included between December 2016 and October 2017 in Affiliated Minda Hospital of Hubei University for Nationalities, who were all the Tujia nationality. Three single nucleotide polymorphic site of BIN1 gene rs744373, rs7561528, rs6733839, and two single nucleotide polymorphic site of ApoE gene rs429358, rs7412, and Genotyping and sub-genotyping of ApoE genes were tested using ligase detection reaction technique(LDR), and gene polymorphisms of BIN1 and ApoE were analyzed with Logistic regression analysis. Results: The basic information was not statistically significan different between healthy control group and aMCI group (P>0.05); there were no statistically significant in genotype distribution among the 3 SNPs of BIN1 gene(rs744373, rs7561528, rs6733839) and between the 2 SNPs of ApoE gene(rs429358, rs7412) and its allelic profile (P>0.05), which conformed to Hardy-Weinberg balance; BIN1 gene rs744373 polymorphic site allele C was the risk factor of aMCI (OR 2.33, 95% CI 1.09-4.98, P=0.029), especially BIN1 gene rs744373 polymorphic site recessive model CC/CT+ TT increased the risk of aMCI disease (OR 2.29, 95% CI 1.15-4.59, P=0.019). The difference in genotype distribution of ApoE sub-genotype ε2/2, ε2/3, ε2/4, ε3/3, ε3/4, ε4/4 and allele ε2, ε3, ε4 genes between two groups were significantly different (P<0.05), Carrying ApoEε2 may be a protective factor for aMCI (OR 0.46, 95% CI 0.22-0.96, P=0.039) and carrying ApoE ε4 may be a risk factor for aMCI (OR 2.13, 95% CI 1.18-3.83, P=0.012). Conclusions: The incidence of aMCI in Tujia region of Enshi may be related to the rs744373 polymorphic site of BIN1 gene, ApoEε2 is the protective factor and ApoEε4 is the risk factor for aMCI in Tujia region of Enshi, but it still needs to be further verified by a large sample population.
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Proteínas Adaptadoras de Transdução de Sinal/genética , Apolipoproteínas E/genética , Disfunção Cognitiva/genética , Proteínas Nucleares/genética , Polimorfismo Genético , Proteínas Supressoras de Tumor/genética , Alelos , China , Genótipo , HumanosRESUMO
Topological insulators and graphene present two unique classes of materials, which are characterized by spin-polarized (helical) and nonpolarized Dirac cone band structures, respectively. The importance of many-body interactions that renormalize the linear bands near Dirac point in graphene has been well recognized and attracted much recent attention. However, renormalization of the helical Dirac point has not been observed in topological insulators. Here, we report the experimental observation of the renormalized quasiparticle spectrum with a skewed Dirac cone in a single Bi bilayer grown on Bi(2)Te(3) substrate from angle-resolved photoemission spectroscopy. First-principles band calculations indicate that the quasiparticle spectra are likely associated with the hybridization between the extrinsic substrate-induced Dirac states of Bi bilayer and the intrinsic surface Dirac states of Bi(2)Te(3) film at close energy proximity. Without such hybridization, only single-particle Dirac spectra are observed in a single Bi bilayer grown on Bi(2)Se(3), where the extrinsic Dirac states Bi bilayer and the intrinsic Dirac states of Bi(2)Se(3) are well separated in energy. The possible origins of many-body interactions are discussed. Our findings provide a means to manipulate topological surface states.
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OBJECTIVE: To investigate the effects of a dual phosphoinosmde-3-kinase (PI3K)/ mammalian target of rapamycin (mTOR) inhibitor, PI-103, cooperating with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) on the laryngeal squamous carcinoma Hep-2 cells. METHODS: Hep-2 cells were divided into 7 groups: LY294002 group, Rapamycin group, PI-103 group, LY294002+ TRAIL group, Rapamycin+ TRAIL group, PI-103+ TRAIL group and control group.The cell cycle and apoptosis of Hep-2 cells were assessed by flow cytometry.For PI-103 group, PI-103+ TRAIL group and control group, migration and invasion ability were measured by transwell migration and invasion assay respectively.The expression of relative proteins in apoptosis and PI3K/AKT/mTOR signal pathway was examined by Western blotting. RESULTS: Combination of PI-103 and TRAIL could make cell cycle arrest at S phase (G1: 1.80%±0.30%; G2: 0.00), inhibit cell proliferation, and enhance apoptosis (66.78%±2.93%) (P<0.05). Combination of PI-103 and TRAIL could statistically decrease the migration and invasion number of Hep-2 cells (17.0±3.4, 18.4±5.4) than that of PI-103 group (41.2±3.8, 41.6±4.7). PI-103 could inhibit PI3K/AKT/mTOR signal pathway by decreasing the protein expression of p-AKT and p-4E-BP1.Comparing with the control group, the expression of cysteinyl aspartate specific proteinase (Caspase) 9, 8, 3 were increased while the expression of Cyclin D1, Cyclin E1, p-AKT, p-4E-BP1 were decreased in PI-103 and PI-103+ TRAIL group (P<0.05). CONCLUSION: Enhanced anti-tumor effects was observed by combination of PI-103 and TRAIL on laryngeal cancer cells in vitro and this combined administration might be a promising strategy for clinical treatment of laryngeal cancer.
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Transdução de Sinais , Animais , Apoptose , Carcinoma de Células Escamosas , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Cromonas , Ciclina D1 , Ciclina E , Furanos , Neoplasias de Cabeça e Pescoço , Humanos , Neoplasias Laríngeas , Morfolinas , Proteínas Oncogênicas , Fosfatidilinositol 3-Quinases , Piridinas , Pirimidinas , Carcinoma de Células Escamosas de Cabeça e Pescoço , Ligante Indutor de Apoptose Relacionado a TNF , Serina-Treonina Quinases TORRESUMO
HoxB7 is involved in cell migration and metastasis in many malignant tumors. But, the role of HoxB7 in lung adenocarcinoma has not been elucidated. In the present study, we aimed to clarify the function of HoxB7 in the progression of lung adenocarcinoma. The protein expression of HoxB7 was examined by immunohistochemical assay in human lung adenocarcinoma tissues, and lentivirus-mediated HoxB7 shRNA (Lv-shHoxB7) was transfected into lung adenocarcinoma cells to evaluate cell proliferation and invasive potential indicated by MTT and Transwell assays. As a result, the protein expression level of HoxB7 was increased in lung adenocarcinoma tissues compared with the adjacent non-tumor tissues (56.25% vs 31.25%, P=0.014), and was positively correlated with the lymph node metastasis in patients with lung adenocarcinoma (P=0.036). Moreover, knockdown of HoxB7 decreased the proliferation and invasion of lung adenocarcinoma cells followed by decreased expression of TGF-ß/SMAD3, vascular endothelial growth factor A (VEGFA) and matrix metalloproteinase-2 (MMP-2). Taken together, our findings demonstrate that increased expression of HoxB7 is associated with tumor metastasis in patients with lung adenocarcinoma and HoxB7 may be implicated in promoting the development of lung adenocarcinoma through activation of the TGF-ß/SMAD3 signaling.
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Adenocarcinoma/metabolismo , Proteínas de Homeodomínio/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas de Neoplasias/metabolismo , Transdução de Sinais , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Adenocarcinoma/patologia , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Metástase NeoplásicaRESUMO
The surface magnetic property plays a key role in determining magnetic related quantum phenomena of magnetic topological insulators. Using spin-polarized scanning tunneling microscopy, we investigate the surface magnetism and anisotropy of a Cr doped topological insulator: Cr(0.05)Sb(1.95)Te(3). It is found that the topological surface state of Cr(0.05)Sb(1.95)Te(3) is spin polarized in the surface plane while the bulk shows a ferromagnetism with an out-of-plane easy axis. The upper and lower branch of the helical Dirac cone harbors the opposite spin polarization and the polarization at the Dirac point is zero. Our results show the complexity of surface magnetism of magnetic doped topological insulators.
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By combining scanning tunneling microscopy and spectroscopy, angle-resolved photoemission spectroscopy, and density functional theory band calculations, we directly observe and resolve the one-dimensional edge states of single bilayer (BL) Bi(111) islands on clean Bi(2)Te(3) and Bi(111)-covered Bi(2)Te(3) substrates. The edge states are localized in the vicinity of step edges having an â¼2 nm wide spatial distribution in real space and reside in the energy gap of the Bi(111) BL. Our results demonstrate the existence of nontrivial topological edge states of single Bi(111) bilayer as a two-dimensional topological insulator.
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Objective: To investigate risk factors for the long-term prognosis of primary focal segmental glomerulosclerosis (FSGS) and associated with renal prognosis in children. Methods: A retrospective study was conducted by collecting clinical data including general information, clinical features and renal pathological findings of 124 children with primary FSGS in Department of Pediatrics of Jinling Hospital from January 2003 to December 2019. The cumulative renal survival rate was calculated by Kaplan-Meier survival analysis. The risk factors related to renal prognosis were identified by Cox regression risk model analysis and receiver operating characteristic (ROC) curve. Results: Among 124 children, 94 were males (75.8%) and 30 were females (24.2%). The children were 16 (14, 17) years of age at the time of kidney biopsies. There were 102 cases (82.3%) aged from 13 to 18 years. The period of follow-up was 64.8 (32.1, 86.0) months. There were 49 cases (39.5%) with nonspecific variant, 33 cases (26.6%) with tip variant, 22 cases (17.7%) with collapsing variant, 14 cases (11.3%) with cellular variant and 6 cases (4.8%) with periportal variant. The data of Kaplan-Meier survival analysis showed that cumulative renal survival rates of end-stage kidney disease (ESKD) or ≥50% decline in estimated glomerular filtration rate (eGFR) from baseline at the year of 5, 10 and 15 after renal biopsies were 66.9%, 51.4% and 21.0% respectively. Multivariate Cox regression analysis showed that hypertension, glomerular segmental sclerosis ratio, moderate to severe chronic tubulointerstitial lesions were independent risk factors for progressing to ESKD or ≥50% reduction in eGFR from baseline in pediatric FSGS (HR=5.28, 1.03, 7.81, 95%CI 2.77-10.05, 1.01-1.04, 4.08-14.98, all P<0.01). ROC curve analysis showed glomerular segmental sclerosis ratio (AUC=0.734, P<0.05, optimal cut-off value=25.4%, sensitivity=50.0%, specificity=88.6%), moderate and severe chronic renal tubulointerstitial lesions (AUC=0.724, P<0.05, sensitivity=46.3%, specificity=98.6%) had good efficacy in evaluating renal outcomes of FSGS. Conclusions: The long-term prognosis of FSGS in children is poor. The risk factors of poor prognosis in children with FSGS are hypertension, moderate to severe chronic renal tubulointerstitial lesions and glomerular segmental sclerosis (≥25.4%).
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Glomerulosclerose Segmentar e Focal , Hipertensão , Falência Renal Crônica , Adolescente , Criança , Feminino , Glomerulosclerose Segmentar e Focal/complicações , Humanos , Falência Renal Crônica/etiologia , Masculino , Prognóstico , Estudos Retrospectivos , EscleroseRESUMO
Most ferromagnetic and antiferromagnetic substances show a simple collinear arrangement of the local spins. Under certain circumstances, however, the spin configuration is non-collinear. Scanning tunneling microscopy with its potential atomic resolution is an ideal tool for investigating these complex spin structures. Non-collinearity can be due to topological frustration of the exchange interaction, due to relativistic spin-orbit coupling or can be found in excited states. Examples for all three cases are given, illustrating the capabilities of spin-polarized scanning tunneling microscopy.
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Submonolayer deposition of 3d transition metals such as Cr, Mn, Fe, Co, and Ni on Pd(110) at room temperature causes the formation of monoatomic chains of Pd as identified with scanning tunneling microscopy and spectroscopy. In agreement with recent theoretical predictions [Phys. Rev. B 79, 155410 (2009)], the substitution of Pd substrate atoms with the deposited atoms of 3d metals is found to be responsible for the formation of Pd atomic chains. This finding clarifies the long-debated issue about the chemical composition of the atomic chains grown on Pd(110) and points out the intriguing processes in the formation of self-assembled and self-organized nanostructures.
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Ácidos Aristolóquicos , Medicamentos de Ervas Chinesas , Humanos , Ácidos Aristolóquicos/efeitos adversos , Masculino , Lactente , Medicamentos de Ervas Chinesas/efeitos adversos , Nefropatias/induzido quimicamente , Aristolochia/química , Aristolochia/efeitos adversos , Rim/patologia , Rim/efeitos dos fármacosRESUMO
The majority of prostate epithelial cell lines stably expressing wild-type (wt) or mutant (mt) androgen receptor (AR) are derived from metastatic prostate cancers. Therefore, the wt AR-expressing RC-165N/human telomerase reverse transcriptase (hTERT) cell line derived from the benign prostate tissue of an African-American patient provides a unique opportunity to assess the functional status of AR in a cellular context not studied before. Although androgen-induced expression of known androgen responsive genes such as PMEPA1, and NDRG1 was observed in RC-165N/hTERT, this cell line expresses prostate-specific antigen (PSA) at significantly lower levels. Chromatin immunoprecipitation assay revealed androgen-dependent binding of AR to androgen response elements of PSA, PMEPA1 and NDRG1 genes. Similarities, as well as differences were noted in the expression of androgen responsive genes between RC-165N/hTERT and LNCaP cells. Comprehensive evaluations of AR functions in RC-165N/hTERT cells suggest that whereas some features of known AR functions are maintained in this benign prostatic tissue-derived cell line, other AR functions are not retained. Objective evaluations of similar cell lines will lead to the understanding of AR functions in prostate growth and differentiation.
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Células Epiteliais/metabolismo , Hiperplasia Prostática/metabolismo , Receptores Androgênicos/metabolismo , Telomerase/genética , Linhagem Celular Transformada , Análise por Conglomerados , Di-Hidrotestosterona/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Antígeno Prostático Específico/metabolismo , Hiperplasia Prostática/genética , Hiperplasia Prostática/patologia , Receptores Androgênicos/fisiologia , Elementos de RespostaRESUMO
To assess the efficacy and safety of the SGLT-2 inhibitors as adjunct therapy to insulin in T1DM, clinical trials indexed in PubMed, Cochrane Library, EMbase from inception through April 5, 2016. A meta-analysis was conducted on trials of SGLT-2 inhibitors in patients with T1DM on insulin therapy using RevMan 5.3 software. Of the 371 articles identified, ten met eligibility criteria. Seven clinical trials including four randomized controlled trials and 581 patients were included. Compared with the control group, SGLT-2 inhibitors group had significantly reduced fasting plasma glucose by 0.69 mmol/L [1.32; 0.07], glycosylated hemoglobin A1C by 0.37% [0.54; 0.20], body weight by 2.54 kg [3.48; 1.60] and total daily insulin dose by 6.22 IU [8.04; 4.40]. The total incidence of adverse events (AEs), hypoglycemia, and genital and urinary infections were also similar to placebo, while an increased incidence of diabetic ketoacidosis (DKA) (n = 16) was seen in SGLT-2 inhibitors group. The present study demonstrates that SGLT-2 inhibitors are effective as adjunct therapy to insulin in T1DM, heralding improved glycemic control, reduced body weight and total daily insulin dose without an increase in total AEs, hypoglycemia, or genital and urinary infections. However, the risk of DKA should be carefully monitored in future clinical trials.
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Diabetes Mellitus Tipo 1/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Inibidores do Transportador 2 de Sódio-Glicose , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/patologia , Humanos , Hipoglicemia/induzido quimicamente , Hipoglicemia/metabolismo , Hipoglicemiantes/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco , Transportador 2 de Glucose-Sódio , Infecções Urinárias/induzido quimicamente , Infecções Urinárias/metabolismoRESUMO
Two cell lines of human embryonal carcinoma, Tera-1 and Tera-2, have been found to exhibit a 4- to 6-fold amplification of protooncogene c-Ki-ras2. The polyadenylic acid selected RNA also showed 8-fold or greater enhancement, showing marked elevation in the level of two major mRNAs, 5.7 and 4.0 kilobases, and two additional minor mRNAs, 2.3 and 1.2 kilobases, as compared with those of a normal human embryonic fibroblast cell line, MRC-5. More than one-half of the number of tumor samples obtained from metastatic human embryonal carcinomas also showed c-Ki-ras2 gene amplification and enhanced mRNA expression. However, the c-Ki-ras2 gene amplification did not always lead to enhanced mRNA expression, and some embryonal carcinomas showed mRNA overexpression without apparent c-Ki-ras2 gene amplification. These results suggest that human embryonal carcinomas may have c-Ki-ras2 amplification and/or overexpression before in vitro culture. Among various chromosomal changes observed in Tera-1 and Tera-2 cells, there were anomalies in chromosome 12 in which c-Ki-ras2 is located although these karyological changes alone could not account for the amplification observed. It is suggested that the genomic instability and active DNA replication during the early developmental period may give rise to changes involving c-Ki-ras2 which may contribute to oncogenic processes.
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Proteínas de Neoplasias/genética , Proteínas Proto-Oncogênicas/genética , Teratoma/genética , Aneuploidia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular , Coriocarcinoma/genética , Coriocarcinoma/patologia , Aberrações Cromossômicas , Cromossomos Humanos Par 12/ultraestrutura , DNA de Neoplasias/genética , Feminino , Fibroblastos/análise , Amplificação de Genes , Regulação da Expressão Gênica , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Proteínas de Neoplasias/biossíntese , Poli A/biossíntese , Gravidez , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas p21(ras) , RNA Mensageiro/biossíntese , RNA Neoplásico/biossíntese , Teratoma/metabolismo , Teratoma/patologia , Neoplasias Uterinas/genética , Neoplasias Uterinas/patologiaRESUMO
A cloned line of S + L- mink lung cells (A clone), which exhibited a flat morphology, was superinfected with a novel dual-tropic virus (E1BX-MuLV) showing a broad host range and a B-tropism. These cells gave rise to transformed cells with two phenotypes: those which were still anchorage-dependent (AD), and those which readily detached spontaneously from the substratum and grew in suspension. A clone of these AD cells (B clone) was isolated and compared with a clone of the anchorage-independent suspension-cultured (AISC) cells (C clone). While the C clone exhibited a high oncogenicity and ability to metastasize in nude mice, the A and B clones were not tumorigenic. The integrated v-mos was greatly amplified in the C clone, and moderately increased in the B clone as compared with the A clone. The amounts of v-mos mRNA expressed by B and C clones paralleled those of v-mos sequence in their chromosomal DNA, whereas there was no detectable v-mos mRNA in the A clone. Thus, conversion of S + L- mink cells from an AD growth to an AISC phenotype accompanied by manifestation of oncogenicity and metastatic potential in nude mice is associated with amplification of integrated v-mos gene and its enhanced expression. Furthermore, a revertant (D clone) showing AD phenotype was derived from the C clone by selective growth in ouabain. This revertant exhibited a markedly decreased oncogenicity in nude mice, although the copy numbers of integrated v-mos gene and its mRNA did not differ from those of the parent C clone. While more p37mos protein was found in the C than in the D clone, it was not detectable in the A and B clone. The amounts of helper virus-related mRNA and infectious E1BX-MuLV were markedly higher in the B than in the C and D clones. It is concluded that v-mos gene amplification and overexpression is necessary for these cells to exhibit oncogenicity, but other factors associated with ouabain-resistance can modify or suppress its oncogenicity despite the v-mos amplification and mRNA overexpression.
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Transformação Celular Neoplásica/patologia , Transformação Celular Viral , Proteínas dos Retroviridae/fisiologia , Animais , Linhagem Celular , Genes Virais , Vírus da Leucemia Murina/fisiologia , Pulmão , Camundongos , Camundongos Nus , Vison , Metástase Neoplásica , Neoplasias Experimentais/etiologia , Neoplasias Experimentais/patologia , Proteínas Oncogênicas v-mos , Oncogenes , FenótipoRESUMO
Intravitreal injection of the protease inhibitor leupeptin causes a rapid accumulation of lipofuscin-like autofluorescent inclusions in the retinal pigment epithelium (RPE) of the eye. In vitamin A-deprived animals, similar inclusions form in response to leupeptin treatment, but they do not become autofluorescent. Because vitamin A is necessary to the development of fluorescence, it appears likely that retinoids are directly incorporated into the inclusions. Experiments were conducted to determine whether this is the case. Rats were reared on a diet containing retinoic acid as the only retinoid. Retinoic acid cannot be utilized in visual transduction by the retina. When the eyes had been over 90% depleted of visual cycle retinoids, the animals were given a single intramuscular injection of 3H-all-trans retinol. After 7 days, when visual cycle retinoids had returned to an average of almost 70% of normal, the animals were given an intravitreal injection of leupeptin in each eye. At either 1 day or 7 days after the leupeptin treatment, some of the animals were dark-adapted for at least 12 h. The eyes were enucleated and fixed under dim red light. A region of each retina just superior to the optic nerve head was examined with electron microscopic autoradiography. At both one day and 7 days after the leupeptin treatment, the radiolabel in the RPE was primarily associated with the leupeptin induced inclusion bodies. Label was also present in the photoreceptor outer segments. The localization of vitamin A to the leupeptin-induced inclusions in the RPE strongly suggests that vitamin A is covalently bound to outer segment proteins that have been phagocytosed by the RPE but remain undegraded due to protease inhibition. This bound vitamin A is probably responsible for the autofluorescence of the leupeptin-induced inclusions. Vitamin A is not likely to be bound through a Schiff base linkage, since retinal-Schiff base compounds do not exhibit lipofuscin-like fluorescence.
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Corpos de Inclusão/metabolismo , Leupeptinas/farmacologia , Lipofuscina/metabolismo , Epitélio Pigmentado Ocular/efeitos dos fármacos , Inibidores de Proteases/farmacologia , Vitamina A/metabolismo , Animais , Masculino , Epitélio Pigmentado Ocular/metabolismo , Ratos , Ratos Endogâmicos F344RESUMO
During the aging process the retinal pigment epithelium (RPE) accumulates autofluorescent lysosomal storage bodies (lipofuscin). Data from previous studies led to the hypothesis that at least one of the fluorescent components of RPE lipofuscin is formed by reaction of vitamin A aldehyde with phosphatidylethanolamine (PE) in the photoreceptor outer segments. Experiments were performed to test this hypothesis. All-trans retinaldehyde was incubated with isolated bovine photoreceptor outer segments and with synthetic liposomes. Liposomes were made with two different lipid compositions. One type of liposome consisted of a mixture of lipids, including phosphatidylcholine (PC), none of which contained a primary amine. The other liposome type was identical in composition accept that some of the PC was replaced with an equimolar amount of phosphatidylethanolamine (PE). After incubation of the samples, aliquots were examined with fluorescence microscopy to assess whether any lipofuscin-like fluorescence had developed. Lipids were extracted from additional aliquots of the samples and analyzed with thin layer chromatography. Photoreceptor outer segments incubated with retinaldehyde developed an intense golden yellow fluorescent emission when illuminated with 395-440 nm light. Similar fluorescence developed in the liposomes containing PE, whereas the liposomes lacking PE or any other primary amine did not develop any detectable fluorescence. The development of fluorescence in the samples in situ correlated with the appearance of an orange colored component in the lipid extracts that displayed a weak red emission upon ultraviolet light illumination. Incorporation of this component into liposomes resulted in the appearance of a golden yellow fluorescent emission. The results of these experiments suggest that retinal, generated during visual pigment bleaching can react with PE in the photoreceptor outer segments to form a fluorophore, a derivative of which subsequently accumulates in RPE lipofuscin. An RPE lipofuscin fluorophore was previously shown to be identical to a reaction product of retinal and ethanolamine. This fluorophore is probably derived from the reaction product of outer segment PE and retinal.
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Lipofuscina/biossíntese , Lipossomos/metabolismo , Retinaldeído/metabolismo , Segmento Externo da Célula Bastonete/metabolismo , Animais , Bovinos , Fluorescência , Fosfatidiletanolaminas/metabolismoRESUMO
Twenty-five human eyes of various ages from eye bank donors and surgical enucleations were obtained for ultrastructural cytochemical demonstration of acid phosphatase (AcPase) and arylsulfatase B (ASB) in the retinal pigment epithelium (RPE) and Bruch's membrane. Results with post-mortem (less than 10 hr) tissues were comparable to those of fresh specimens. Vigorous reactivity was demonstrated in lysosomes of RPE and choriocapillary endothelium but no reactive sites were found in Bruch's membrane, although many lysosome-like dense bodies occurred in eyes greater than 20 yr of age. Granular drusen of 30-70-yr-olds contained no reactive bodies. In eyes greater than 80 years old blebs of RPE basal cytoplasm protruding into Bruch's membrane contained reactive lysosomes. We conclude that the RPE ordinarily does not extrude or exocytose active lysosomes (ie, phagolysosomes, other secondary lysosomes, residual bodies, lipofuscin) or lysosomal enzymes. Aged RPE, however, extrudes cytoplasm with active lysosomes into Bruch's membrane. The possible impact of this process on the extracellular connective tissue is discussed, particularly with regard to age-related deterioration of Bruch's membrane and neovascularization.