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1.
Skin Res Technol ; 26(3): 362-368, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31859440

RESUMO

BACKGROUND: For personalized skin care, noninvasive quantitative methods to evaluate facial skin characteristics are important. Janus-III is one of the most widely used imaging analysis devices in the skin care industry in Korea. Janus-III generates values for a range of skin characteristics. Due to the convenience of obtaining results for a variety of skin characteristics in a single measurement, the use of Janus-III in cosmetic stores and research institutes has been recently increasing. However, the consistency of skin measurements of Janus-III has not been elucidated yet. MATERIALS AND METHODS: In this study, we repeated skin measurements three times for 70 different subjects and compared each numerical value in order to assess the consistency of the Janus-III. For this purpose, we compared between-sample distances and within-sample distances. RESULTS: We found important patterns for future analyses in terms of consistency. First, the average values of skin measurement categories were more reliable than individual part values of facial segments. Second, center part values such as forehead and nose were more reliable than side part values such as left and right part segments. CONCLUSION: If researchers who use Janus-III for studies of facial characteristics analyze average and center part values first, they can obtain relatively reliable patterns of facial skin characteristics.


Assuntos
Face/anatomia & histologia , Processamento de Imagem Assistida por Computador/métodos , Pele/anatomia & histologia , Pontos de Referência Anatômicos/fisiologia , Face/diagnóstico por imagem , Face/fisiologia , Feminino , Testa/anatomia & histologia , Humanos , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Masculino , Nariz/anatomia & histologia , Fotografação/métodos , Porfirinas/análise , Porfirinas/fisiologia , República da Coreia , Sebo/metabolismo , Sebo/fisiologia , Pele/diagnóstico por imagem , Envelhecimento da Pele/fisiologia , Fenômenos Fisiológicos da Pele , Pigmentação da Pele/fisiologia , Raios Ultravioleta
2.
Curr Drug Metab ; 12(2): 186-97, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21395539

RESUMO

Unlike most cytochrome P450 (CYP) enzymes, murine hepatic CYP2A5 is induced during pathological conditions that result in liver injury including hepatotoxicity mediated by xenobiotics, hepatitis caused by various microbial agents and liver neoplasia. Since CYP2A5 metabolizes various important xenobiotics including nicotine and pro-carcinogens such as nitrosamines and aflatoxin B(1), altered gene expression could affect tobacco addiction, hepatotoxicity and hepatocarcinogenesis. This article synthesizes the current knowledge concerning hepatic expression of Cyp2a5 including the transcriptional and post-transcriptional regulatory mechanisms, pathophysiological conditions associated with enzyme induction such as oxidative and endoplasmic reticulum stress and altered lipid and energy homeostasis as well as the known exogenous and putative endogenous substrates. Knowledge of the stimuli responsible for the unique overexpression of CYP2A5 during liver injury may provide clues to a functional role for this enzyme and the impact of variable CYP2A5 expression on xenobiotic metabolism and toxicity, disease development and the adaptive response to hepatocellular stress.


Assuntos
Hidrocarboneto de Aril Hidroxilases/biossíntese , Hidrocarboneto de Aril Hidroxilases/genética , Regulação Enzimológica da Expressão Gênica/fisiologia , Heme/metabolismo , Homeostase/fisiologia , Fígado/enzimologia , Fígado/fisiopatologia , Estresse Fisiológico/fisiologia , Animais , Hidrocarboneto de Aril Hidroxilases/antagonistas & inibidores , Citocromo P-450 CYP2A6 , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/genética , Metabolismo Energético/fisiologia , Indução Enzimática , Inibidores Enzimáticos/farmacologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/genética , Homeostase/efeitos dos fármacos , Homeostase/genética , Humanos , Metabolismo dos Lipídeos/genética , Metabolismo dos Lipídeos/fisiologia , Fígado/efeitos dos fármacos , Oxirredução/efeitos dos fármacos , Porfirinas/metabolismo , Porfirinas/fisiologia , Pirazóis/farmacologia , Processamento Pós-Transcricional do RNA/fisiologia , Estresse Fisiológico/genética , Fatores de Transcrição/fisiologia , Xenobióticos/farmacologia
3.
Artigo em Inglês | MEDLINE | ID: mdl-19351566

RESUMO

Porphyrins are a widespread group of pigments in nature, but, contrary to melanins and carotenoids, their occurrence as plumage colorants seems to be anecdotal and their function, if any, is unknown. Using thin-layer chromatography and high pressure liquid chromatography, we have found coproporphyrin III, the same porphyrin type previously reported in owls, in the plumage of nestling black-shouldered kites (Elanus caeruleus). The first plumage grown at the nest in this species includes reddish-brown contour feathers in the upperparts, and particularly in the breast area, which fade during the weeks-long post-fledging period to become either gray or white consistent with the definitive adult plumage. In these reddish feathers, we have also found small amounts of pheomelanins and traces of eumelanin. The contribution of each pigment to the final colour perceived by birds or other animals is unknown. In white and grey feathers of the same species no porphyrin was found, and only traces of eumelanin were detected in the grey ones. The fact that the reddish feathers are only found in the juvenal plumage, when individuals are vulnerable in an open nest, leads us to hypothesize a camouflage role for this ephemeral plumage. As porphyrins are involved, although not exclusively, we can for the first time ascribe them a function in the plumage of birds.


Assuntos
Falconiformes/fisiologia , Plumas/fisiologia , Melaninas/fisiologia , Pigmentação/fisiologia , Porfirinas/fisiologia , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina
4.
J Pharm Sci ; 98(1): 105-13, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18464274

RESUMO

The interaction between cationic porphyrin, a potential valuable anti-tumor and antibiotic drug, and human serum albumin (HSA) was investigated using spectroscopy methods. The binding constants were obtained using fluorescence quenching method (K(SV) = (3.24 +/- 0.29) x 10(4) M(-1)) and surface plasmon resonance (SPR) spectroscopy (K(A) = (6.287 +/- 0.407) x 10(4) M(-1)). The association rate constant (k(a) = 1622 +/- 72.9 M(-1) s(-1)) and dissociation rate constant (K(d) = 0.02589 +/- 0.0024 s(-1)) of the binding process were also calculated. Compared with the two results, it was known that one of the binding sites was near the tryptophan residue and also there existed other binding sites. The Fourier transform infrared (FT-IR) spectroscopy and circular dichroism (CD) spectroscopy indicated that the confirmation of HSA was nearly not affected with the addition of porphyrin.


Assuntos
Porfirinas/metabolismo , Albumina Sérica/metabolismo , Cátions/análise , Cátions/metabolismo , Dicroísmo Circular , Humanos , Porfirinas/fisiologia , Ligação Proteica/fisiologia , Conformação Proteica , Estrutura Secundária de Proteína , Albumina Sérica/análise , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier , Ressonância de Plasmônio de Superfície
5.
Pharmacol Ther ; 114(3): 345-58, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17368550

RESUMO

Heme, a complex of iron and protoporphyrin IX (PPIX), senses and utilizes oxygen in nearly all living cells. It is an essential component of various hemoproteins, including those involved in oxygen transport and storage (hemoglobin, myoglobin), electron transfer, drug and steroid metabolism (cytochromes), and signal transduction (nitric oxide synthases, guanylate cyclases). The movement of heme into and within cells was thought to occur by diffusion. However, the chemical properties of heme make diffusion too slow to keep pace with biological processes, and accumulation of heme and its pre-cursor porphyrins in membranes can be deleterious. Due to pro-oxidant effects, heme may cause damage to DNA, proteins, the cytoskeleton and membrane lipids. The intracellular localization and concentrations of protoporphyrins and heme are tightly regulated, and elevated levels are linked to pathologic conditions (e.g., anemia, lead poisoning, thalassemias) associated with the formation of membrane lipid-damaging, reactive oxygen species. Until recently a mechanism to transport heme and protoporphyrins into organelles of mammalian cells had not been identified. In this review, we focus on the roles of the recently identified heme/porphyrin transport proteins heme carrier protein 1 (HCP1), FLVCR, Abcg2 and Abcb6 and discuss how these transporters contribute to intracellular heme and porphyrin homeostasis.


Assuntos
Proteínas de Transporte/fisiologia , Heme/fisiologia , Homeostase/fisiologia , Porfirinas/fisiologia , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Proteínas de Transporte/metabolismo , Heme/biossíntese , Heme/metabolismo , Humanos , Proteínas de Membrana Transportadoras/metabolismo , Proteínas de Neoplasias/metabolismo , Transportador de Folato Acoplado a Próton , Receptores de GABA-A/fisiologia , Receptores Virais/metabolismo
6.
ACS Chem Biol ; 1(10): 627-9, 2006 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-17168567

RESUMO

Hemes are porphyrins that play a critical role in diverse biological processes. Heme synthesis culminates in the mitochondrial matrix, but the eight-step biosynthetic pathway is spatially shared between the mitochondria and cytoplasm. A recent paper describes the nature of the transporter that translocates the heme precursor coproporphyrinogen III into the mitochondria for heme synthesis. The identification of ABCB6 (ATP-binding cassette, subfamily B, member 6) and future studies aimed at precisely delineating the mechanism and the physiological nature of its ligand(s) will further enhance our current understanding of the intracellular movement of tetrapyrroles in eukaryotes.


Assuntos
Porfirinas/fisiologia , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Transporte Biológico , Citoplasma/metabolismo , Heme/química , Humanos , Ferro/metabolismo , Ligantes , Mitocôndrias/metabolismo , Modelos Biológicos , Pirróis/metabolismo , Vitamina B 12/metabolismo
7.
J Gravit Physiol ; 11(2): P79-80, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16235423

RESUMO

The investigation of long-term space flight (SF) effect on the blood cells function is of great importance for modern space biology and medicine. We established that the number of discocytes decreased in the period of early rehabilitation after long-term SF. After SF plasma membrane fluidity and phospholipid content decreased and cholesterol content increased. After SF the amount of haemoglobin decreased and the parameters characterizing haemoglobin haemoporyphyrin (HH) conformation changed. We suppose that erythrocyte shape, membrane fluidity and HH conformation are among factors affecting oxygen transfer during and after space flight.


Assuntos
Membrana Eritrocítica/fisiologia , Eritrócitos/fisiologia , Fluidez de Membrana , Voo Espacial , Ausência de Peso , Colesterol/sangue , Deformação Eritrocítica , Hemoglobinas/fisiologia , Humanos , Fosfolipídeos/sangue , Porfirinas/sangue , Porfirinas/fisiologia
8.
J Bacteriol ; 185(8): 2528-37, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12670977

RESUMO

The porphyrin requirements for growth recovery of Porphyromonas gingivalis in heme-depleted cultures are investigated. In addition to physiologically relevant sources of heme, growth recovery is stimulated by a number of noniron porphyrins. These data demonstrate that, as for Haemophilus influenzae, reliance on captured iron and on exogenous porphyrin is manifest as an absolute growth requirement for heme. A number of outer membrane proteins including some gingipains contain the hemoglobin receptor (HA2) domain. In cell surface extracts, polypeptides derived from HA2-containing proteins predominated in hemoglobin binding. The in vitro porphyrin-binding properties of a recombinant HA2 domain were investigated and found to be iron independent. Porphyrins that differ from protoporphyrin IX in only the vinyl aspect of the tetrapyrrole ring show comparable effects in competing with hemoglobin for HA2 and facilitate growth recovery. For some porphyrins which differ from protoporphyrin IX at both propionic acid side chains, the modification is detrimental in both these assays. Correlations of porphyrin competition and growth recovery imply that the HA2 domain acts as a high-affinity hemophore at the cell surface to capture porphyrin from hemoglobin. While some proteins involved with heme capture bind directly to the iron center, the HA2 domain of P. gingivalis recognizes heme by a mechanism that is solely porphyrin mediated.


Assuntos
Heme/metabolismo , Hemoglobinas/metabolismo , Porfirinas/fisiologia , Porphyromonas gingivalis/metabolismo , Receptores de Superfície Celular/metabolismo , Adesinas Bacterianas/biossíntese , Adesinas Bacterianas/química , Adesinas Bacterianas/metabolismo , Meios de Cultura , Cisteína Endopeptidases/biossíntese , Cisteína Endopeptidases/química , Cisteína Endopeptidases/metabolismo , Deuteroporfirinas , Cisteína Endopeptidases Gingipaínas , Hemaglutininas/biossíntese , Hemaglutininas/química , Hemaglutininas/metabolismo , Peptídeos/metabolismo , Porfirinas/metabolismo , Porphyromonas gingivalis/crescimento & desenvolvimento , Protoporfirinas , Receptores de Superfície Celular/biossíntese , Receptores de Superfície Celular/química , Proteínas Recombinantes/metabolismo
9.
Med Hypotheses ; 59(6): 615-21, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12445498

RESUMO

When I was learning pathology a wise and knowledgeable mentor described a final common pathway that allows many diseases to overlap in their presentation. This pathway was never identified for it was unknown. Recent books by physicians have suggested that maintaining body balance and/or treatment by a substance could halt or repair damage caused by a wide array of diseases, once again suggesting a common thread amongst diseases. Again no mention was made regarding what was this common denominator. I have been interested in people who have more than one disease, feeling that there must be a link. My interest in the porphyrin pathway has strengthened that impression. Since finding Doss's list of diseases having porphyrin abnormalities unrelated to a porphyria, I have worked on models that would allow me to show a way where porphyrin abnormalities may be a part of the final common pathway for all disease. I have finally decided that a spider's web is that model. The following discussion will attempt to demonstrate that this hypothesis could be true.


Assuntos
Diabetes Mellitus/fisiopatologia , Fibromialgia/fisiopatologia , Esclerose Múltipla/fisiopatologia , Porfirias/fisiopatologia , Porfirinas/fisiologia , Homeostase , Humanos , Modelos Biológicos
10.
Arch Microbiol ; 178(6): 443-9, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12420164

RESUMO

A strain of Dehalosprillum multivorans, designated strain N, was isolated from the same source as the formerly described tetrachloroethene (PCE)-dechlorinating D. multivorans, herein after referred to as strain K. Neither growing cells nor cell extracts of strain N were able to dechlorinate PCE. The pceA and pceB genes encoding for the PCE-reductive dehalogenase were detected in cells of strain N; and they were 100% homologous to the corresponding genes of strain K. Since the PCE dehalogenase of D. multivorans strain K contains a corrinoid cofactor, the corrinoids of strain N cells were extracted. Analysis of the corrinoids revealed the absence of the specific corrinoid, which is the cofactor of the PCE dehalogenase of strain K cells. RT-PCR of mRNA indicated that the pceA gene was transcribed in strain N cells to a far lower extent than the pceA gene of strain K under the same experimental conditions. Western blot analysis of crude extracts of strain N showed that, if at all, an insignificant amount of the apoprotein of the PCE dehalogenase was present. The results indicate that the inability of strain N to dechlorinate is due to the absence of the corrinoid cofactor of the enzyme mediating PCE dechlorination.


Assuntos
Epsilonproteobacteria/enzimologia , Oxirredutases/metabolismo , Porfirinas/fisiologia , Cromatografia Líquida de Alta Pressão , Corrinoides , Epsilonproteobacteria/genética , Epsilonproteobacteria/metabolismo , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa
11.
Cell Biol Int ; 26(4): 347-53, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11991664

RESUMO

To understand the relationship between the location of organelles and cellular function, we examined the dynamic state of cytoplasmic organelles and cytoskeleton in polynuclear Ehrlich ascites tumor (EAT) cells fused with hemagglutinating virus of Japan (HVJ; Sendai virus) by confocal laser scanning microscopy. Irregular fused cells gradually became spherical during culture, and nuclei and mitochondria were redistributed in the fused cell; nuclei formed a cluster surrounded by mitochondria. F-actin, vimentin, and microtubules were also reorganized with the redistribution of cell organelles. Further, when the morphological change was inhibited by L4-1, a chlorophyll-like substance derived from silkworm faeces, or pyropheophorbide-a, the arrangement of organelles and cytoskeleton remained disturbed, suggesting that the movement of the cytoskeleton is closely associated with cell shape and the distribution of cytoplasmic organelles.


Assuntos
Carcinoma de Ehrlich , Citoesqueleto/fisiologia , Células Híbridas/fisiologia , Organelas/fisiologia , Vírus Sendai , Actinas/fisiologia , Animais , Carcinoma de Ehrlich/patologia , Carcinoma de Ehrlich/fisiopatologia , Células Híbridas/ultraestrutura , Camundongos , Microscopia Confocal , Porfirinas/fisiologia , Vírus Sendai/fisiologia , Vírus Sendai/ultraestrutura , Células Tumorais Cultivadas
12.
Cell Biol Int ; 26(4): 355-61, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11991665

RESUMO

Fused Ehlrich ascites tumor (EAT) cells induced by hemagglutinating virus of Japan (HVJ; Sendai virus) had an irregular shape, reflecting the shape of cell aggregates before fusion. During subsequent culture, the fused cells gradually took on a spherical form within 60 min. Examination of the fused cells revealed a vigorous endocytosis of the cell membrane during the morphological change. When EAT cells were treated with porphyrin derivatives, and the morphological change to a spherical form was inhibited, endocytosis of fused cells was also suppressed, suggesting that the change is closely associated with endocytotic activity. Further examination with porphyrin derivatives and hydrogen peroxide suggested that the inhibition of morphological change is due to the suppression of endocytosis by active oxygen species produced by these substances. Experiments using an endocytotic inhibitor, methylamine, indicated that endocytosis is essential for the morphological change that occurs in the fused cells.


Assuntos
Carcinoma de Ehrlich/fisiopatologia , Membrana Celular/fisiologia , Endocitose/fisiologia , Células Híbridas/fisiologia , Vírus Sendai , Animais , Carcinoma de Ehrlich/ultraestrutura , Dextranos/metabolismo , Fluoresceína-5-Isotiocianato/análogos & derivados , Fluoresceína-5-Isotiocianato/metabolismo , Células Híbridas/patologia , Camundongos , Porfirinas/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Células Tumorais Cultivadas
13.
Cell Mol Biol (Noisy-le-grand) ; 48(8): 835-43, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12699241

RESUMO

We studied the effect of arsenic exposure on the haem biosynthetic pathway in the rat and humans. Significant increases in protoporphyrin IX, coproporphyrin III, coproporphyrin I were observed in the blood, liver and kidney, and in the urine of rats after a single dose of arsenic. The level of increase was dependent on the arsenic species present. Most of porphyrin concentrations in the tissues increased within 24 hr and urinary excretion elevated within 48 hr. In the human study, we collected urine samples from 113 people who live in Xing Ren of Guizhou Province, a coal-borne arsenicosis endemic area in southwest of PR China and from 30 people who live in Xing Yi (about 80 km southwest of Xing Ren) where arsenicosis is not prevalent. We analyzed the urinary porphyrins using HPLC. Results indicate that all urinary porphyrins were higher in the arsenic exposed group than those in the control group. Women, children and older age people spend much of their time indoors, they had greater increases of urinary arsenic and porphyrins. They were the higher risk groups among the study subjects. A positive correlation between the urinary arsenic levels and porphyrin concentrations demonstrated the effect of arsenic on haem biosynthesis. Significant alteration in the porphyrin excretion profiles of the younger age (<20 y) arsenic exposed group suggested that porphyrins could be used as early warning biomarkers for chronic exposure to arsenic.


Assuntos
Arsênio/sangue , Arsênio/toxicidade , Arsênio/urina , Biomarcadores , Porfirinas/fisiologia , Fatores Etários , Animais , Cromatografia Líquida de Alta Pressão , Coproporfirinas/sangue , Coproporfirinas/metabolismo , Coproporfirinas/urina , Creatinina/urina , Feminino , Humanos , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Masculino , Porfirinas/química , Protoporfirinas/sangue , Protoporfirinas/metabolismo , Protoporfirinas/urina , Ratos , Ratos Wistar , Fatores de Tempo , Distribuição Tecidual
14.
Indian J Med Res ; 116: 99-105, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12619448

RESUMO

BACKGROUND & OBJECTIVES: The widespread occurrence of antibiotic resistant strains of Pseudomonas aeruginosa in hospitals is a matter of growing concern. We report the results of a study on photodynamic inactivation of antibiotic resistant strain of P. aeruginosa by delta-aminolaevulinic acid (ALA). METHODS: Exponentially growing P. aeruginosa cells were incubated in growth medium with ALA for various durations. Subsequently, the cells were washed and resuspended in phosphate buffered saline (PBS). These cells were incubated with different concentrations of glutathione (GSH) in PBS for 15 min. Porphyrins synthesized with and without GSH were detected by fluorescence spectroscopy. The ALA treated cells were irradiated with light at 405 nm with and without subsequent incubation in GSH. Cell survival was measured by colony forming ability. RESULTS: Incubation of cells in growth medium with ALA led to increased synthesis of protoporphyrins in cells which saturated beyond 4 h. The level of protoporphyrin synthesis increased significantly when ALA treated cells were subsequently incubated with GSH in PBS for 15 min. Irradiation of cells incubated with ALA alone led to weak inactivation. However, substantial cell death was observed in ALA treated cells irradiated in the presence of 15 mM GSH. INTERPRETATION & CONCLUSION: Photodynamic inactivation of P. aeruginosa by ALA induced porphyrins can be enhanced if ALA treated cells are further incubated with GSH and irradiated using 405 nm light. These findings may be useful for inactivation of antibiotic resistant strains of P. aeruginosa causing burn and wound infections in hospitalized patients.


Assuntos
Ácido Aminolevulínico/farmacologia , Resistência a Medicamentos , Luz , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/fisiologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , Humanos , Pseudomonas aeruginosa/efeitos da radiação
15.
Histol Histopathol ; 16(1): 309-17, 2001 01.
Artigo em Inglês | MEDLINE | ID: mdl-11193207

RESUMO

Photodynamic therapy (PDT) is a clinically approved treatment for the ocular condition age-related macular degeneration, and certain types of cancer. PDT is also under investigation for other ocular, as well as, immune-mediated and cardiovascular indications. PDT is a two step procedure. In the first step, the photosensitizer, usually a porphyrin derivative, is administered and taken up by cells. The second step involves activation of the photosensitizer with a specific wavelength of visible light. Exposure to light of an activating wavelength generates reactive oxygen species within cells containing photosensitizer. PDT with porphyrin photosensitizers induces rapid apoptotic cell death, an event which may be attributed to the close association of these compounds with mitochondria. Thus, PDT is an attractive method to treat ailments such as cancer, viral infections, autoimmune disorders and certain cardiovascular diseases in which the apoptotic program may be compromised. The present review examines the cellular events triggered at lethal and sublethal PDT doses and their relationship to the subsequent effects exerted upon cells.


Assuntos
Fotoquimioterapia , Porfirinas/fisiologia , Animais , Apoptose/fisiologia , Apoptose/efeitos da radiação , Morte Celular/fisiologia , Morte Celular/efeitos da radiação , Humanos , Luz , Porfirinas/efeitos da radiação
16.
FEBS Lett ; 462(3): 467-71, 1999 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-10622747

RESUMO

Some guanine-rich oligonucleotides inhibit HIV infectivity through interaction with the gp120 glycoprotein. Besides, photoinactivation of viruses attracts attention for blood decontamination. The feasibility of targeting a red light-absorbing chlorin-type photosensitizer to gp120 through covalent coupling with 8-mer phosphodiester oligodeoxynucleotides is investigated. Some conjugates inhibit binding of antibodies directed to gp120. Inhibition is significantly increased upon red light activation. The activity of the conjugates correlates with their ability to self-associate, a process strongly favored by the propensity of the hydrophobic chlorin moiety to dimerize. Thus, the photosensitizer moiety both promotes structures with a higher affinity for gp120 and, upon light activation, can induce site-directed damages to the protein.


Assuntos
Proteína gp120 do Envelope de HIV/metabolismo , Oligonucleotídeos/farmacologia , Transtornos de Fotossensibilidade , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/farmacologia , Sequência de Aminoácidos , Dimerização , Relação Dose-Resposta à Radiação , Ensaio de Imunoadsorção Enzimática , Proteína gp120 do Envelope de HIV/efeitos dos fármacos , Proteína gp120 do Envelope de HIV/imunologia , Proteína gp120 do Envelope de HIV/efeitos da radiação , Luz , Dados de Sequência Molecular , Oligonucleotídeos/metabolismo , Porfirinas/fisiologia
17.
J Struct Biol ; 116(3): 377-89, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8812996

RESUMO

It is known that the Harderian gland of male Syrian hamster synthesizes a much smaller amount of porphyrins than the gland of the female and that castration greatly increases this synthesis. We have studied in this experimental model the behavior of the different classes of secretory cells and their role in the synthesis of porphyrins, attempting to clarify the participation of these compounds in the cell damage leading to the formation of clear cells previously described in the gland of females. We have also investigated the mechanism underlying the death of these secretory cells after porphyrin accumulation (necrosis vs apoptosis). To achieve this, we have utilized the following techniques: (a) morphometrical; (b) ultrastructural; (c) biochemical (fluorescence spectrophotometry); and (d) molecular (DNA nick-end labeling in methacrylate sections and dot blot analysis). The glands from male hamsters (serving as control) present a very low rate of damaged cells that progressively rises after castration. This rise runs parallel to that of porphyrin synthesis, porphyrin deposits, and the decrease of Type II secretory cells. The damage and subsequent death of the secretory cells in the gland is produced by the deposit of porphyrins in the mitochondrial membrane. This porphyrin accumulation leads to a complete mitochondrial destruction that finally results in cell death and its secretion into the lumen. We finally conclude that this event is not a physiological cell death (apoptosis) but the consequence of the toxic accumulation of porphyrins (necrosis).


Assuntos
Glândula de Harder/patologia , Orquiectomia , Porfirinas/fisiologia , 5-Aminolevulinato Sintetase/análise , 5-Aminolevulinato Sintetase/biossíntese , Análise de Variância , Animais , Apoptose , Morte Celular , Células Cultivadas , Cricetinae , DNA/análise , Dexametasona/farmacologia , Feminino , Glândula de Harder/metabolismo , Glândula de Harder/ultraestrutura , Masculino , Mesocricetus , Microscopia Eletrônica , Necrose , Porfirinas/biossíntese , RNA/análise , Caracteres Sexuais , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia
18.
Proc Natl Acad Sci U S A ; 93(6): 2459-63, 1996 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-8637896

RESUMO

Previously we showed that an Escherichia coli hemH mutant, defective in the ultimate step of heme synthesis, ferrochelatase, is somewhat better than 100-fold more sensitive than its wild-type parent in tumbling to blue light. Here we explore the effect of a hemG mutant, defective in the penultimate step, protoporphyrinogen oxidase. We found that a hemG mutant also is somewhat better than 100-fold more sensitive in tumbling to blue light compared to its wild-type parent. The amount of non-iron porphyrins accumulated in hemG or hemH mutants was more than 100-fold greater than in wild type. The nature of these accumulated porphyrins is described. When heme was present, as in the wild type, the non-iron (non-heme) porphyrins were maintained at a relatively low concentration and tumbling to blue light at an intensity effective for hemG or hemH did not occur. The function of tumbling to light is most likely to allow escape from the lethality of intense light.


Assuntos
Escherichia coli/fisiologia , Heme/fisiologia , Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Oxirredutases/fisiologia , Porfirinas/fisiologia , Proteínas de Escherichia coli , Luz , Movimento , Protoporfirinogênio Oxidase
19.
Photochem Photobiol ; 62(4): 780-9, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7480155

RESUMO

The effects of topical and systemic administration of 5-aminolevulinic acid (ALA) were examined in several murine tumor systems with regard to porphyrin accumulation kinetics in tumor, skin and blood, vascular and tumor cell photosensitization and tumor response after light exposure. Marked, transient increases in porphyrin levels were observed in tumor and skin after systemic and topical ALA. Rapid, transient, dose-dependent porphyrin increases were also observed in blood; these were pronounced after systemic ALA injection and mild after topical application. They were highest within 1 h after ALA injection, thereafter declining rapidly. This matched the clearing kinetics of injected exogenous protoporphyrin IX (PpIX). Initially, vascular photosensitivity changed inversely to blood porphyrin levels, increasing gradually up to 5 h post-ALA, as porphyrin was clearing from the bloodstream. This pattern was again matched by injected, exogenous PpIX. After therapeutic tumor treatment vascular disruption of the tumor bed, while observed, was incomplete, especially at the tumor base. Minimal direct tumor cell kill was found at low photodynamic therapy (PDT) doses (250 mg/kg ALA, 135 J/cm2 light). Significant, but limited (< 1 log) direct photodynamic tumor cell kill was obtained when the PDT dose was raised to 500 mg/kg systemic ALA, followed 3 h later by 270 J/cm2, a dose that was however toxic to the animals. The further reduction of clonogenic tumor cells over 24 h following treatment was moderate and probably limited by the incomplete disruption of the vasculature. Tumor responses were highest when light treatment was carried out at the time of highest tumor porphyrin content rather than at the time of highest vascular photosensitivity. Tumor destruction did not reach the tumor base, regardless of treatment conditions.


Assuntos
Ácido Aminolevulínico/farmacologia , Neoplasias do Colo/tratamento farmacológico , Fibrossarcoma/tratamento farmacológico , Fotoquimioterapia , Fármacos Fotossensibilizantes , Porfirinas/fisiologia , Administração Tópica , Ácido Aminolevulínico/administração & dosagem , Ácido Aminolevulínico/uso terapêutico , Animais , Neoplasias do Colo/irrigação sanguínea , Neoplasias do Colo/patologia , Coproporfirinas/administração & dosagem , Coproporfirinas/farmacologia , Coproporfirinas/uso terapêutico , Fibrossarcoma/irrigação sanguínea , Fibrossarcoma/patologia , Injeções Intraperitoneais , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Neoplasias Induzidas por Radiação/irrigação sanguínea , Neoplasias Induzidas por Radiação/tratamento farmacológico , Neoplasias Induzidas por Radiação/patologia , Neovascularização Patológica , Porfirinas/biossíntese , Protoporfirinas/administração & dosagem , Protoporfirinas/farmacologia , Protoporfirinas/uso terapêutico
20.
Photodermatol Photoimmunol Photomed ; 11(1): 25-30, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7654564

RESUMO

The effects of ultraviolet A (UVA) and blue light on ferrochelatase protein, and its mRNA level, in 5-aminolevulinic acid (ALA)-loaded A431 cells was evaluated. Western blot analysis of ferrochelatase protein showed a protein band of 43 kDa. There was a decrease in the protein concentration 24 h and 48 h after irradiation of these cells. In contrast, as judged by Northern blot analysis, there was no change in ferrochelatase mRNA level. Measurement of ALA synthase activity showed an ALA dose-dependent but radiation-independent decrease of enzyme activity, suggesting an end-product feedback inhibition. Since reactive oxygen species generated by porphyrin-induced photochemical reaction may be involved in the decrease in ferrochelatase protein, the effect of scavengers of reactive oxygen species was evaluated by measuring porphyrin accumulation in irradiated, ALA-loaded A431 cells. Porphyrin accumulation was significantly decreased in the presence of singlet oxygen scavenger sodium azide (0.05 mM, 40.6% suppression) or hydroxyl radical scavenger mannitol (5.0 mM, 45.0% suppression). These data suggest that the photochemical reaction induced by porphyrin and irradiation resulted in a decrease in ferrochelatase protein content, but had no effect on ferrochelatase mRNA level nor on ALA synthase activity. The decrease in protein was partly mediated by the reactive oxygen species.


Assuntos
5-Aminolevulinato Sintetase/metabolismo , 5-Aminolevulinato Sintetase/efeitos da radiação , Epiderme/enzimologia , Ferroquelatase/metabolismo , Ferroquelatase/efeitos da radiação , Porfirinas/fisiologia , Northern Blotting , Western Blotting , Linhagem Celular , Relação Dose-Resposta à Radiação , Epiderme/metabolismo , Sequestradores de Radicais Livres/farmacologia , Humanos , Luz , Porfirinas/metabolismo , Raios Ultravioleta
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