RESUMO
Glucotoxicity may exert its deleterious effects on pancreatic ß-cell function via a myriad of mechanisms, leading to impaired insulin secretion and, eventually, type 2 diabetes. ß-cell communication requires gap junction channels to be present among these cells. Gap junctions are constituted by transmembrane proteins of the connexins (Cxs) family. Two Cx genes have been identified in ß cells, Cx36 and Cx30.2. We have found evidence that the glucose concentration on its own is sufficient to regulate Cx30.2 gene expression in mouse islets. In this work, we examine the involvement of the Cx30.2 protein in the survival of ß cells (RIN-m5F). METHODS: RIN-m5F cells were cultured in 5 mM D-glucose (normal) or 30 mM D-glucose (high glucose) for 24 h. Cx30.2 siRNAs was used to downregulate Cx30.2 expression. Apoptosis was measured by means of TUNEL, an annexin V staining method, and the cleaved form of the caspase-3 protein was determined using Western blot. RESULTS: High glucose did not induce apoptosis in RIN-m5F ß cells after 24 h; interestingly, high glucose increased the Cx30.2 total protein levels. Moreover, this work found that the downregulation of Cx30.2 expression in high glucose promoted apoptosis in RIN-m5F cells. CONCLUSION: The data suggest that the upregulation of Cx30.2 protects ß cells from hyperglycemia-induced apoptosis. Furthermore, Cx30.2 may be a promising avenue of therapeutic investigation for the treatment of glucose metabolic disorders.
RESUMO
The semisynthesis of novel derivatives of lupeyl palmitate and 3ß-palmitoyloxy-olean-12-ene by introduction of a pyrazine at C-2 / C-3 and modifications of the relatively unexplored C-30 position of lupeol derivatives was conducted, and their cytotoxic and anti-inflammatory activities were evaluated. The derivatives 7, 10 and 11 significantly inhibited the tumor cell lines U251, K562, HCT-15, MCF-7 and SKLU-1, and compounds 7 and 11 were more active (IC50 25.4 ± 2.0 µM and 7.1 ± 0.4 µM, respectively) than the positive control (etoposide (IC50 31.5 ± 2.2 µM) in the tumor line PC-3. Introduction of the pyrazine at C-2 / C-3 in compounds 1 and 2 or modification at C-30 of compound 1 decreased the anti-inflammatory activity in the TPA-induced mouse ear edema. Following the results of the PASS online evaluation of the potential biological activity of the natural compounds and their derivatives, the inhibition of pNF-κB translocation to the prostate cancer (PC-3) cell nucleus was investigated and the binding mode of compounds 7, 10 and 11 with the human NF-κB receptor was explored by a molecular docking study. These derivatives bound directly or close to the amino acids that form the DNA recognition site. The ADMET physicochemical parameters of the fifteen compounds were further analyzed in silico using Molinspiration calculations indicating the potential of compounds 7, 10 and 11 for further investigation.
Assuntos
Antineoplásicos , Triterpenos , Animais , Anti-Inflamatórios/farmacologia , Antineoplásicos/química , Linhagem Celular Tumoral , Masculino , Camundongos , Simulação de Acoplamento Molecular , Estrutura Molecular , Triterpenos Pentacíclicos/farmacologia , Pirazinas , Relação Estrutura-Atividade , Triterpenos/química , Triterpenos/farmacologiaRESUMO
Indazole is considered a very important scaffold in medicinal chemistry. It is commonly found in compounds with diverse biological activities, e.g., antimicrobial and anti-inflammatory agents. Considering that infectious diseases are associated to an inflammatory response, we designed a set of 2H-indazole derivatives by hybridization of cyclic systems commonly found in antimicrobial and anti-inflammatory compounds. The derivatives were synthesized and tested against selected intestinal and vaginal pathogens, including the protozoa Giardia intestinalis, Entamoeba histolytica, and Trichomonas vaginalis; the bacteria Escherichia coli and Salmonella enterica serovar Typhi; and the yeasts Candida albicans and Candida glabrata. Biological evaluations revealed that synthesized compounds have antiprotozoal activity and, in most cases, are more potent than the reference drug metronidazole, e.g., compound 18 is 12.8 times more active than metronidazole against G. intestinalis. Furthermore, two 2,3-diphenyl-2H-indazole derivatives (18 and 23) showed in vitro growth inhibition against Candida albicans and Candida glabrata. In addition to their antimicrobial activity, the anti-inflammatory potential for selected compounds was evaluated in silico and in vitro against human cyclooxygenase-2 (COX-2). The results showed that compounds 18, 21, 23, and 26 display in vitro inhibitory activity against COX-2, whereas docking calculations suggest a similar binding mode as compared to rofecoxib, the crystallographic reference.
Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/farmacologia , Indazóis/química , Anti-Infecciosos/síntese química , Anti-Inflamatórios não Esteroides/síntese química , Antiprotozoários/síntese química , Antiprotozoários/química , Antiprotozoários/farmacologia , Técnicas de Química Sintética , Simulação por Computador , Ciclo-Oxigenase 2/química , Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase 2/química , Inibidores de Ciclo-Oxigenase 2/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Entamoeba histolytica/efeitos dos fármacos , Giardia lamblia/efeitos dos fármacos , Células HeLa , Humanos , Indazóis/síntese química , Simulação de Acoplamento Molecular , Trichomonas vaginalis/efeitos dos fármacosRESUMO
9-[(3-chloro)phenylamine]-2-[3-(diethylamine)propylamine]thiazolo[5,4-b]quinolone (D3ClP) is a bioisostere of N-(4-(acridin-9-ylamino)-3-methoxyphenyl)methanesulfonamide (m-AMSA) a DNA topoisomerase II inhibitor with proven cytotoxic activity and known to induce DNA damage and apoptotic cell death in K562 cells. However, recent evidence is not consistent with DNA topoisomerase II (DNA TOP2) as the primary target of D3ClP, in contrast to m-AMSA. We provide evidence of histone γH2AX phosphorylation at Ser135 in HeLa cells treated with D3ClP, a marker of DNA double strand repair through Mre11-Rad50-Nbs1 (MRN) pathway. Using two-dimensional gel electrophoresis and mass spectrometry, the upregulation of the protein GRP78, the cleavage of Cytokeratin 18, and the downregulation of prothymosine, calumenin, and the α chain of the nascent polypeptide associated complex were observed in HeLa cells treated with D3ClP. An increase in GRP78 has been related with the onset and progression of the unfolded protein response (UPR), a process aimed to reduce endoplasmic reticulum (ER) stress and protein misfolding. The IRE1-α dependent splicing of mRNA encoding X-box binding protein 1 was detected. Microtubule-associated Proteins 1A/1B, Light Chain 3-II (LC3b-II) accumulation was observed, and suggest some involvement of autophagy. The production of the pro-apoptotic protein DNA-damage-inducible protein 153 (GADD-153) was also detected. These results, are consistent with the induction of the UPR and the DNA-Damage Response in D3ClP-treated HeLa cells, and are also consistent with a concurrent apoptotic cell death. J. Cell. Biochem. 118: 1164-1173, 2017. © 2016 Wiley Periodicals, Inc.
Assuntos
Aminoquinolinas/farmacologia , Dano ao DNA , Proteômica/métodos , Tiazóis/farmacologia , Resposta a Proteínas não Dobradas/efeitos dos fármacos , Retículo Endoplasmático/efeitos dos fármacos , Chaperona BiP do Retículo Endoplasmático , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Células HeLa , Histonas/metabolismo , Humanos , Fosforilação , Proteoma/efeitos dos fármacos , Serina/metabolismo , Fator de Transcrição CHOP/metabolismoRESUMO
OBJECTIVES: The aim of this study was to determine the cellular and molecular mechanisms of cell death induced by mammea A/BA and A/BB (3 : 1) on K562 cells. METHODS: These compounds were isolated from Calophyllum brasiliense and its cytotoxicity was tested using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell death was evaluated by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and immunocytofluorescence of active caspase-3. Genotoxicity was tested using comet assay. Lastly, a chemoinformatic analysis was performed with Osiris-Molinspiration software. KEY FINDINGS: The mixture of mammea A/BA and A/BB (3 : 1) showed cytotoxic activity against K562 cells (IC50 = 43.5 µm). TUNEL positive cells and active caspase-3 were detected after treatment. Genotoxicity of mammea A/BA and A/BB on K562 was detected since first hour of treatment. Additionally, mammea A/BA and A/BB were found to be in compliance with Lipinski 'rule of 5' suggesting that they possess strong potential of druglikeness. CONCLUSIONS: The overall results confirm and extend the knowledge about coumarins as an important resource of antitumor drugs, and indicate that these compounds could be used in further preclinical studies against leukaemia.
Assuntos
Calophyllum/química , Cumarínicos/química , Cumarínicos/farmacologia , Leucemia/tratamento farmacológico , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Caspase 3/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Células K562 , Leucemia/metabolismoRESUMO
As a part of our research in the chemistry of chalcones we have prepared four pyrimidine monoadducts of bis-chalcones through the reaction with 6-amino-1,3-dimethyl uracil. These compounds displayed cytotoxicity with a massive vacuolation in different human cell lines in vitro. Compound 6 was the most cytotoxic inducer of vacuoles, this compound induced G1 phase cell cycle arrest, and their cytotoxicity went without morphological and biochemical evidence of apoptotic cell death in HeLa cells. In addition, our results showed that this vacuole formation does not require de novo protein synthesis and the content vacuolar is acidic. Compound 6 induce necrotic cell death with excessive vacuolation, similar to a process of autophagy. Spautin-1 an inhibitor of autophagy, decreased the transformation of microtubule-associated protein 1 light chain 3 (LC3B-I) to LC3B-II and the vacuolation induced by compound 6 in HeLa cells, both autophagy processes. These compounds could be of pivotal importance in the study of non-apoptotic cell death with vacuole formation and could be useful in research into new autophagy inhibitors agents.
Assuntos
Antineoplásicos/farmacologia , Chalconas/farmacologia , Uracila/análogos & derivados , Antineoplásicos/síntese química , Antineoplásicos/química , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Chalconas/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Estrutura Molecular , Relação Estrutura-Atividade , Células Tumorais Cultivadas , Uracila/química , Uracila/farmacologiaRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Justicia spicigera is used for the empirical treatment of cervical cancer in Mexico. Recently, we showed that Justicia spicigera extracts exerted cytotoxic and antitumoral effects and the major component of this extract was kaempferitrin (KM). MATERIALS AND METHODS: The cytotoxic and apoptotic effect of KM on human cancer cells and human nontumorigenic cells were evaluated using MTT and TUNEL assays, and Annexin V/Propidium iodide detection by flow cytometry. The effect of KM on cell cycle was analyzed by flow cytometry with propidium iodide. The apoptotic and cell cycle effects were also evaluated by western blot analysis. Also, different doses of KM were injected intraperitoneally daily into athymic mice bearing tumors of HeLa cells during 32 days. The growth and weight of tumors were measured. RESULTS: KM induces high cytotoxic effects in vitro and in vivo against HeLa cells. The general mechanisms by which KM induces cytotoxic effects include: cell cycle arrest in G1 phase and apoptosis via intrinsic pathway in a caspase dependent pathway. Also, KM exerts chemopreventive and antitumor effects. CONCLUSION: KM exerts cytotoxic and antitumor effects against HeLa cells.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Quempferóis/farmacologia , Animais , Antineoplásicos Fitogênicos/uso terapêutico , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ciclina D1/metabolismo , Humanos , Marcação In Situ das Extremidades Cortadas , Quempferóis/uso terapêutico , Masculino , Camundongos , Camundongos Nus , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Fitoterapia , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: D3CLP (9-[(3-chloro)phenylamine]-2-[3-(diethylamine)propylamine]thiazolo[5,4-b]quinoline) is a potent cytotoxic thiazolo[5,4-b]quinoline synthetic derivative that induces apoptosis of leukemia cells, while it displays low toxicity towards non-tumoral cells. The aim of this study was to determine if D3CLP can enhance the cytotoxicity of other antineoplastic drugs. MATERIALS AND METHODS: Leukemia, breast and cervical cancer cell lines were exposed to D3CLP-alone or in combination with imatinib, tamoxifen or cisplatin, respectively. Cell viability after treatment was evaluated by the MTT assay, and cell death by the TUNEL assay. The effects of combined treatments were analyzed by combination index and isobolographic analysis. RESULTS: Antiproliferative activity results indicate that D3CLP in combination with antineoplastic drugs induced a synergistic effect, at 3:1 and 1:1 ratios for D3CLP plus imatinib in K-562 leukemia cells, and at a 3:1 ratio for D3CLP with cisplatin in HeLa cells, as determined by their combination index. Furthermore, isobolographic analysis demonstrated a significant synergism for a 3:1 combination ratio of D3CLP with cisplatin in HeLa cells. In addition, TUNEL assay suggests cell death by apoptosis of HeLa cells after treatment with D3CLP and its combination with cisplatin at a 3:1 ratio. CONCLUSION: Overall the results indicate that D3CLP, in combined preparation with antineoplastic drugs, is a good candidate for pre-clinical studies in the treatment of different carcinoma cell types.
Assuntos
Aminoquinolinas/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Cisplatino/farmacologia , Tiazóis/farmacologia , Neoplasias do Colo do Útero/tratamento farmacológico , Aminoquinolinas/administração & dosagem , Benzamidas , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/administração & dosagem , Fragmentação do DNA/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Feminino , Células HeLa , Humanos , Mesilato de Imatinib , Células K562 , Células MCF-7 , Piperazinas/administração & dosagem , Piperazinas/farmacologia , Pirimidinas/administração & dosagem , Pirimidinas/farmacologia , Tamoxifeno/administração & dosagem , Tamoxifeno/farmacologia , Tiazóis/administração & dosagem , Neoplasias do Colo do Útero/patologiaRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Phoradendron serotinum is commonly used in Mexican traditional medicine for the empirical treatment of cancer. However, there are no studies regarding the antitumoral or immunomodulatory activities of Phoradendron serotinum. MATERIALS AND METHODS: The in vivo toxicity of ethanolic extracts of Phoradendron serotinum (PSE) was evaluated in mice according to the Lorke procedure. The in vitro immunomodulatory effects of PSE were evaluated estimating the effects of PSE on the pinocytosis, NO production and lysosomal enzyme activity in murine macrophages RAW 264.7. The effects of PSE on the proliferation of murine splenocytes and NK cell activity were also assayed. The cytotoxic effects on TC-1 (lung murine cancer cells) were evaluated using the MTT assay, whereas the apoptotic effect of PSE on TC-1 cells was evaluated using TUNEL assay. Also, different doses of PSE were injected intraperitoneally daily into C57BL/6 mice bearing tumors of TC-1 cells during 25 days. The growth and weight of tumors was measured. In addition, the levels of IL-2, IL-6, IL-12, IL-23 and IFN-γ in murine serum and supernatants of K562 cell-murine splenocyte cocultures were measured. RESULTS: PSE stimulated the proliferation, pinocytosis and lysosomal enzyme activity in murine macrophages with a similar potency than lypopolisaccharides 1 µg/ml. In addition, PSE stimulated the proliferation of murine splenocytes and induced the NK cell activity. PSE showed cytotoxic (IC(50)=1.9 µg/ml) and apoptotic effects against TC-1 cells. The LD(50) was 125 mg/kg by intraperitoneal route (i.p.) and 375 mg/kg by oral route. PSE administrated at 1, 5 and 10 mg/kg i.p. inhibited the tumor growth by 18%, 40% and 69%, respectively, in mice bearing TC-1 tumor. PSE increased the in vitro and in vivo release of IL-2, IL-6 and IFN-γ but lacked effect on IL-12 and IL-23 release. CONCLUSIONS: Phoradendron serotinum shows moderate toxic effects in vivo, exerts cytotoxic and apoptotic effects on TC-1 cells. Phoradendron serotinum also has antitumor effects in mice bearing TC-1 tumor and induces immunomodulatory activities in vivo. The results suggest that antitumoral effects of PSE are related with the production of immunity-related cytokines.
Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Fatores Imunológicos/uso terapêutico , Neoplasias/tratamento farmacológico , Phoradendron , Extratos Vegetais/uso terapêutico , Animais , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Citocinas/imunologia , Humanos , Fatores Imunológicos/farmacologia , Células K562 , Células Matadoras Naturais/efeitos dos fármacos , Dose Letal Mediana , Lisossomos/metabolismo , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/metabolismo , Neoplasias/patologia , Óxido Nítrico/metabolismo , Extratos Vegetais/farmacologia , Folhas de Planta , Carga Tumoral/efeitos dos fármacosRESUMO
Thiazolo[5,4-b]quinolines are compounds structurally related to m-Amsacrine (m-Amsa), a potent antileukemic drug that intercalates to DNA and inhibits topoisomerase II in vitro inducing cell death. The clinical use of m-Amsa and other neoplastic drugs is limited due to side effects and drug resistance. In the present study we evaluated one thiazolo[5,4-b]quinoline derivate, 9-[(3-chloro)phenylamine]-2-[3-(diethylamine)propylamine]thiazolo[5,4-b]quinoline (D3CLP), considered isosteric with 9-anilinoacridines, in order to determine its relative cytotoxic activity in tumoral versus non-tumoral cells, as well as the cell death mechanism induced by D3CLP on K-562 human leukemia cells. D3CLP was found to be four times more cytotoxic to tumor cells than Peripheral Blood Monocyte Cells (PBMCs). On the other hand, D3CLP induces cell death without previous cell cycle arrest at any phase, as shown by flow cytometry after 12 h of exposure to this compound. Interestingly, we detected a subdiploid peak 24 h after treatment. Signs of apoptosis were evident, as detected by TUNEL positive cells, chromatin condensation and nuclear fragmentation. Effector caspases activation were assessed with peak activity at 24 h after treatment (as detected by fluorometry assays), at which time a subdiploid peak was found in flow cytometry histograms. All data are consistent with the induction of apoptotic cell death in K-562 cells via effector caspases activation. In conclusion, the significant cytotoxicity of D3CLP together with the cell death type it produces, justifies further experimental and preclinical evaluation of this compound in the effort to find new and highly specific anti-tumor agents against leukemia cells.
Assuntos
Aminoquinolinas/farmacologia , Antineoplásicos/farmacologia , Inibidores de Caspase , Inibidores de Cisteína Proteinase/farmacologia , Tiazóis/farmacologia , Aminoquinolinas/síntese química , Aminoquinolinas/química , Antineoplásicos/síntese química , Antineoplásicos/química , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Inibidores de Cisteína Proteinase/síntese química , Inibidores de Cisteína Proteinase/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Ativação Enzimática/efeitos dos fármacos , Humanos , Células K562 , Estrutura Molecular , Estereoisomerismo , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/química , Células Tumorais CultivadasRESUMO
BACKGROUND: Although the etiology of preeclampsia is still unclear, recent work suggests that changes in circulating angiogenic factors play a key role in its pathogenesis. In the trophoblast of women with preeclampsia, hypoxia-inducible factor 1 alpha (HIF-1α) is over-expressed, and induces the expression of non-angiogenic factors and inhibitors of trophoblast differentiation. This observation prompted the study of HIF-1α and its relation to preeclampsia. It has been described that the C1772T (P582S) and G1790A (A588T) polymorphisms of the HIF1A gene have significantly greater transcriptional activity, correlated with an increased expression of their proteins, than the wild-type sequence. In this work, we studied whether either or both HIF1A variants contribute to preeclampsia susceptibility. RESULTS: Genomic DNA was isolated from 150 preeclamptic and 105 healthy pregnant women. Exon 12 of the HIF1A gene was amplified by PCR, and the genotypes of HIF1A were determined by DNA sequencing.In preeclamptic women and controls, the frequencies of the T allele for C1772T were 4.3 vs. 4.8%, and the frequencies of the A allele for G1790A were 0.0 vs. 0.5%, respectively. No significant differences were found between groups. CONCLUSION: The frequency of the C1772T and G1790A polymorphisms of the HIF1A gene is very low, and neither polymorphism is associated with the development of preeclampsia in the Mexican population.
RESUMO
In rodents, the display of sexual behavior during proestrus-estrus transition depends on the effect of estradiol and progesterone. Progesterone exerts its effects through intracellular receptor (PR) of which two isoforms (PR-A and PR-B) are found, with different regulation and function. In this study the effects of mating on the expression pattern of PR isoforms in the hypothalamus were investigated during proestrus-estrus transition by using western blot. PR-B isoform content significantly diminished during proestrus-estrus transition both in mated and nonmated female rats. In contrast, PR-A isoform content significantly increases during this period in nonmated rats, whereas it does not change in mated animals. These data show that PR isoforms are differentially expressed throughout proestrus-estrus transition and that mating modifies PR isoforms expression in the hypothalamus of the rat.
Assuntos
Regulação da Expressão Gênica , Hipotálamo/metabolismo , Receptores de Progesterona/metabolismo , Comportamento Sexual Animal/fisiologia , Animais , Western Blotting , Estro/metabolismo , Feminino , Expressão Gênica , Perfilação da Expressão Gênica , Masculino , Proestro/metabolismo , Isoformas de Proteínas/biossíntese , Isoformas de Proteínas/genética , Ratos , Ratos Wistar , Receptores de Progesterona/genéticaRESUMO
BACKGROUND: Recent studies showed that Helicobacter pylori existed in the New World prior to the arrival of Columbus. The purpose of the present study was to detect the presence of Helicobacter pylori in pre-Columbian mummies from Northern Mexico. METHODS: Six samples were studied (four samples of gastric remains, tongue-soft palate, and brain remained as negative controls) from two of the six naturally mummified corpses studied (adult male and infant male). Samples were taken from tissues suitable for DNA amplification by Polymerase chain reaction (PCR). DNA was extracted and H. pylori detection was carried out by PCR and hybridized with the pHp probe from 16S rRNA gene. The purified PCR products were cloned and sequenced in both directions. DNA sequences were analyzed with ALIGN and BLAST software. A second amplification was performed using ureB gene by real-time PCR. RESULTS: From four samples of gastric remnant, only two were H. pylori-positive for amplification of a 109 bp DNA fragment; the remaining two were negative, as were the tongue-soft palate and the brain biopsies as well. These PCR products were hybridized with a pHp probe. Nucleotide sequence analysis showed homology with H. pylori in 98 of 99% when compared with the gene bank nucleotide sequence. Only one sample of gastric remnant H. pylori-positive with 16S rRNA gene was also positive for ureB gene from H. pylori. CONCLUSION: This data supported infection with H. pylori in Mexican pre-Columbian mummies dating from approximately 1,350 AC.
Assuntos
Infecções por Helicobacter/história , Helicobacter pylori/genética , Helicobacter pylori/isolamento & purificação , Múmias/microbiologia , Adulto , Antropologia , DNA Bacteriano/análise , DNA Bacteriano/isolamento & purificação , Infecções por Helicobacter/microbiologia , História Medieval , Humanos , Recém-Nascido , Masculino , México , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Estômago/microbiologia , Urease/genéticaRESUMO
Methylation of CpG dinucleotides is an epigenetic mechanism involved in the regulation of gene expression in mammals. The patterns of CpG methylation are specie and tissue specific. The biological machinery of this system comprises a variety of regulatory proteins including DNA methyltransferases, putative demethylases, methyl-CpG binding proteins, histones modifying enzymes and chromatin remodeling complexes. DNA methylation maintains gene silencing and participates in normal development, genomic imprinting and X chromosome inactivation. In contrast, alterations in DNA methylation participate in the induction of some human diseases, especially those involving developmental defects and tumorigenesis. This review summarizes the molecular aspects of DNA methylation and its implications in cancer and other human diseases in which this epigenetic mechanism has been involved. Our understanding of the epigenetic changes that occur in human diseases will be very important for future management. Changes in the patterns of methylation can be used as markers in cancer and their potentially reversible state creates a target for therapeutic strategies involving specific gene re-activation or re-silencing.
Assuntos
Metilação de DNA , Epigênese Genética , Animais , Cromatina/genética , Doenças Genéticas Inatas/genética , Genoma , Mamíferos/genética , Neoplasias/genética , Transcrição Gênica , Cromossomo X/genéticaRESUMO
Methylation of CpG dinucleotides is an epigenetic mechanism involved in the regulation of gene expression in mammals. The patterns of CpG methylation are specie and tissue specific. The biological machinery of this system comprises a variety of regulatory proteins including DNA methyltransferases, putative demethylases, methyl-CpG binding proteins, histones modifying enzymes and chromatin remodeling complexes. DNA methylation maintains gene silencing and participates in normal development, genomic imprinting and X chromosome inactivation. In contrast, alterations in DNA methylation participate in the induction of some human diseases, especially those involving developmental defects and tumorigenesis. This review summarizes the molecular aspects of DNA methylation and its implications in cancer and other human diseases in which this epigenetic mechanism has been involved. Our understanding of the epigenetic changes that occur in human diseases will be very important for future management. Changes in the patterns of methylation can be used as markers in cancer and their potentially reversible state creates a target for therapeutic strategies involving specific gene re-activation or re-silencing.
La metilación del ADN en dinucleótidos CpG es uno de los mecanismos epigenéticos implicados en la regulación de la expresión génica en mamíferos. Los patrones de metilación son específicos para cada especie y tipo de tejido. La maquinaria implicada comprende diferentes proteínas reguladoras incluyendo a las ADN metiltransferasas, desmetilasas putativas, proteínas de unión a CpG metilados, enzimas modificadoras de histonas y complejos remodeladores de la cromatina. La metilación del ADN es de vital importancia para mantener el silenciamiento génico en el desarrollo normal, la impronta genómica y la inactivación del cromosoma X. En contraste, alteraciones en ella están implicadas en algunas enfermedades humanas, especialmente aquéllas relacionadas con defectos en el desarrollo y el proceso neoplásico. Esta revisión resume los aspectos moleculares de la metilación del ADN y su participación en el desarrollo normal, el cáncer y en algunas patologías humanas en las que los mecanismos epigenéticos han sido implicados. El conocimiento de las modificaciones epigenéticas que ocurren en las enfermedades humanas será importante para su manejo futuro. Los cambios en los patrones de metilación podrán ser empleados como marcadores en cáncer y el estado potencialmente reversible de este proceso constituye un blanco ideal para crear estrategias terapéuticas que impliquen la reactivación o el re-silenciamiento de genes específicos.
Assuntos
Animais , Metilação de DNA , Epigênese Genética , Cromatina/genética , Genoma , Doenças Genéticas Inatas/genética , Mamíferos/genética , Neoplasias/genética , Transcrição Gênica , Cromossomo X/genéticaRESUMO
The in vitro exposure of Taenia crassiceps cysticerci to 17-beta estradiol (E2) and progesterone (P4) stimulated their reproduction and infectivity. Testosterone (T4) and dihydrotestosterone (DHT) inhibited their reproduction and reduced their motility and infectivity. E2 and P4 increased, whereas T4 and DHT reduced, the expression of parasite c-fos and c-jun and DNA synthesis. In vitro exposure of cysticerci to sex steroids before their inoculation into recipient noninfected mice resulted in large parasite loads when pretreated with E2 and P4 and in smaller loads when pretreated with T4 and DHT To determine the possible molecular mechanisms by which sex steroids affect T. crassiceps, sex steroid receptors were amplified. Taenia crassiceps expressed estrogen receptors (both alpha and beta isoforms) and androgen receptors but no P4 receptors. These results demonstrate that sex steroids act directly on parasite reproduction by binding to a classic and specific sex steroid receptor on the parasite. The differential response of cysticerci to sex steroids may also be involved in their ability to grow faster in the murine female or feminized male host. This is the first report of direct sex steroid effects on the parasite possibly through sex steroid receptors in the cysticerci.
Assuntos
Di-Hidrotestosterona/farmacologia , Estrogênios/farmacologia , Progesterona/farmacologia , Taenia/efeitos dos fármacos , Testosterona/farmacologia , Animais , DNA de Helmintos/efeitos dos fármacos , DNA de Helmintos/metabolismo , Relação Dose-Resposta a Droga , Feminino , Expressão Gênica/efeitos dos fármacos , Genes fos/efeitos dos fármacos , Genes fos/fisiologia , Genes jun/efeitos dos fármacos , Genes jun/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , RNA de Helmintos/metabolismo , RNA Mensageiro/metabolismo , Reprodução Assexuada/efeitos dos fármacos , Taenia/genética , Taenia/fisiologia , Teníase/parasitologia , Timidina/metabolismo , TrítioRESUMO
Although regression of the endometrium during the rat estrous cycle is a well-recognized event, little is known concerning the mechanisms involved in triggering apoptosis in the rat uterine epithelium. In an attempt to have a better understanding of the mechanisms underlying apoptosis during estrus, we evaluated the expression of several key apoptotic genes of the bcl-2 family during the transition from proestrus to estrus day in the rat. Our results show significant changes in the expression of bcl-2 family genes at midnight before estrus, characterized by a significant increase in the pro-apoptotic ratios: Bax/Bcl-2 and Bcl-xS/Bcl-xL at both mRNA and protein levels. Our results indicate the existence of a positive relation between apoptosis and pro-apoptotic ratios of bcl-2 gene family expression, during the transition from proestrus to estrus day. Importantly, pro-apoptotic signals were detected before ovulation occurred. The overall results suggest that the apoptotic process of the rat endometrium begins at midnight before the day of estrus, may be mediated by Bcl-2 family genes, and precedes ovulation.