RESUMO
The development of the field of materials science, the ability to perform multidisciplinary scientific work, and the need for novel administration technologies that maximize therapeutic effects and minimize adverse reactions to readily available drugs have led to the development of delivery systems based on microencapsulation, which has taken one step closer to the target of personalized medicine. Drug delivery systems based on polymeric microparticles are generating a strong impact on preclinical and clinical drug development and have reached a broad development in different fields supporting a critical role in the near future of medical practice. This paper presents the foundations of polymeric microparticles based on their formulation, mechanisms of drug release and some of their innovative therapeutic strategies to board multiple diseases.
Assuntos
Sistemas de Liberação de Medicamentos/métodos , Microesferas , Nanopartículas/administração & dosagem , Nanopartículas/química , Polímeros/administração & dosagem , Polímeros/química , Animais , Composição de Medicamentos , HumanosRESUMO
The hypothesis that levonorgestrel (LNG) used as an emergency contraceptive interferes with endometrial receptivity remains unproven. We compared the endometrial gene expression profile during the receptive period after administering a single dose of LNG 1.5âmg or placebo on day 1 of the luteal phase. An endometrial biopsy was done on day LH+7 or LH+8 and samples were taken from seven volunteers, each one contributing with one cycle treated with placebo and another with LNG. The expression of 20â383 genes was determined using cDNA microarrays. Real-time RT-PCR was used 1) to confirm the differences found in DNA microarray analysis and 2) to determine the effect of LNG on transcript levels of C3, C4BPα, COX2, MAOA, S100A4, and SERPINB9, known to be upregulated during receptivity, and on cPLA2α, JAK1, JNK1, CTSL1, and GSTP1, known to respond to mifepristone. Additional endometrial biopsies were done during the pre-receptive (LH+3) and receptive (LH+7) period and samples were taken from eight untreated volunteers in order to determine the changes associated with acquisition of receptivity of 14 genes. Mean levels of PAEP, TGM2, CLU, IGF2, and IL6ST mRNAs increased after administering LNG while those of HGD, SAT1, EVA1, LOC90133, ANXA1, SLC25A29, CYB5A, CRIP1, and SLC39A14 decreased. Except for the level of ANXA1 transcript, all changes remained within the range observed in untreated controls, and none of the transcripts responding to mifepristone changed in response to LNG. Post-ovulatory administration of LNG caused minimal changes in gene expression profiling during the receptive period. Neither the magnitude nor the nature or direction of the changes endorses the hypothesis that LNG interferes with endometrial receptivity.
Assuntos
Anticoncepcionais Femininos/farmacologia , Endométrio/efeitos dos fármacos , Endométrio/metabolismo , Perfilação da Expressão Gênica , Levanogestrel/farmacologia , Fase Luteal/efeitos dos fármacos , Fase Luteal/genética , Anticoncepcionais Femininos/administração & dosagem , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Levanogestrel/administração & dosagem , Ciclo Menstrual/efeitos dos fármacos , Ciclo Menstrual/fisiologia , Mifepristona/farmacologia , Progesterona/metabolismo , Reprodutibilidade dos Testes , Transcriptoma/efeitos dos fármacosRESUMO
Estradiol accelerates oviductal embryo transport in the rat through changes of genomic expression in oviductal cells. However, the genes involved are unknown. We used a differential display by reverse transcription-polymerase chain reaction to detect estradiol (E2)-dependent genes in the rat oviduct. Rats on day 2 of pregnancy were untreated or treated with 10 micrograms of E2 and the oviducts were extracted at 30, 180 and 360 min later and used to isolate RNA. Products of reverse transcriptase-PCR, made with pairs of arbitrary and oligo-deoxythymidine primers, were separated on denaturing polyacrylamide gels and candidate bands were excised and reamplified. Truly positive cDNA fragments determined by a single strand conformation polymorphism assay were cloned and sequenced. A ribonuclease protection assay confirmed that clone 25 is up-regulated by E2 in the oviduct at 30, 180 and 360 min. This clone exhibited no homology with known genes and in situ hybridization showed it is only expressed in the epithelial cells of the isthmic segment. Clone 25 is likely to represent a new gene, which is up-regulated by E2 in the epithelium of the isthmic segment of the rat oviduct. Its time frame of response is compatible with a mediator of the effect of E2 on oviductal embryo transport.
Assuntos
Estradiol/farmacologia , Tubas Uterinas/fisiologia , RNA Mensageiro/efeitos dos fármacos , Animais , Sequência de Bases , Fragmentação do DNA , DNA Complementar/genética , Epitélio , Feminino , Expressão Gênica , Hibridização In Situ , Polimorfismo Conformacional de Fita Simples , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transcrição Gênica , Regulação para CimaRESUMO
BACKGROUND: Prostaglandin-E(2) and platelet-activating factor (PAF) are embryonic-derived signals that time embryo passage into the uterus in the mare and hamster respectively. PAF-like activity is detectable in the spent media of preimplantation human embryos and it has been suggested that PAF may be the embryonic signal that controls embryo transport to the uterus in our species. The actions of PAF are regulated at the level of its synthesis and degradation as well as the expression of a specific cell surface receptor (PAFr). The enzyme PAF acetylhydrolase (PAF-AH) degrades PAF. This study was undertaken to examine whether or not PAFr and PAF-AH are expressed in the human Fallopian tube and to identify the cell types in which they are expressed. METHODS: The presence of PAFr mRNA in tissue extracts was investigated using reverse transcription-polymerase chain reaction. We amplified the predicted amplicon for PAFr mRNA from RNA samples extracted from Fallopian tubes. The expression of PAF-AH was detected by Western blot and the localization of PAFr and PAF-AH proteins was detected by immunohistochemistry. RESULTS: Utilizing antibodies against PAFr and PAF-AH, co-localization of the two proteins in the epithelium and stromal cells were demonstrated. CONCLUSIONS: These observations show that the human Fallopian tube expresses PAFr and PAF-AH at a location compatible with the proposed paracrine role of early embryo-derived PAF.
Assuntos
Embrião de Mamíferos/fisiologia , Tubas Uterinas/química , Fosfolipases A/genética , Fator de Ativação de Plaquetas/fisiologia , Glicoproteínas da Membrana de Plaquetas/genética , Receptores de Superfície Celular , Receptores Acoplados a Proteínas G , Útero , 1-Alquil-2-acetilglicerofosfocolina Esterase , Western Blotting , Epitélio/química , Feminino , Expressão Gênica , Humanos , Imuno-Histoquímica , Fosfolipases A/análise , Glicoproteínas da Membrana de Plaquetas/análise , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Estromais/químicaRESUMO
Platelet-activating factor (PAF) is a lipid mediator that has a range of biological effects on various cells and tissues. PAF-like activity has been detected in the spent media of two-cell to morula stage hamster embryos, leading to the suggestion that PAF may be the embryonic signal that hastens embryo transport to the uterus in this species. The present study was undertaken to examine whether the PAF receptor (PAFr) gene is expressed in hamster oviduct, and to identify the cell types in which the gene is expressed. DNA fragments complementary to the coding region of mRNA encoding hamster PAFr were cloned by reverse transcription-polymerase chain reaction (RT-PCR), identified by sequencing and used to prepare hamster specific cRNA probes. The presence of mRNA transcripts encoding the PAFr receptor in the oviduct was investigated by subjecting oviduct mRNA to RT-PCR. Southern blot analysis of the RT-PCR products verified the identity of the presumptive PAFr cDNAs. The cloned cDNA fragment of hamster PAFr was found to be highly conserved with respect to the receptor of other species, having 94.3% sequence similarity to the rat PAFr receptor. Hybridization histochemistry demonstrated that PAFr is expressed in the subepithelial cells and occasionally in the epithelium. In conclusion, expression of PAFr in the hamster oviduct is compatible with the proposed paracrine role of early embryo-derived PAF.