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1.
Eur J Clin Microbiol Infect Dis ; 42(1): 43-52, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36369413

RESUMO

Mycoplasma genitalium (MG) and Trichomonas vaginalis (TV) can lead to long-term sequelae in males and females; however, global prevalence data vary between geographical regions, as these sexually transmitted infections are not included in routine screening. The objective of this study was to use the cobas® TV/MG assay to assess the point prevalence of TV and MG in specimens from men and women over a broad European geographical area. Urine, vaginal, endocervical, and rectal samples were collected from patients aged ≥ 18 years receiving Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (NG) screening as per local standard of care at sites in Belgium, Germany, Spain, and the UK (Wales). Remnant samples were assessed using the cobas TV/MG assay. Analysis of 2795 samples showed that MG prevalence varied slightly across female sample types (range: 1.7-5.8%; p = 0.0042). MG prevalence was higher in male rectal samples (12.5%) than in male urine samples (3.9%; p < 0.0001). TV prevalence was low in male (0.8%; 12/1535) and female (1.3%; 16/1260) samples across all sites. Co-infection of TV/MG with CT or NG was 10.0% (19/190) and 9.6% (7/73), respectively, in both male and female samples. MG and TV prevalence rates were comparable to the published literature in Europe. MG prevalence was highest in male rectal samples; as rectal testing is an off-label use of the cobas TV/MG assay, the clinical utility of this assay for rectal testing should be further investigated.


Assuntos
Infecções por Chlamydia , Gonorreia , Infecções por Mycoplasma , Mycoplasma genitalium , Infecções Sexualmente Transmissíveis , Trichomonas vaginalis , Humanos , Feminino , Masculino , Prevalência , Bélgica/epidemiologia , Espanha/epidemiologia , Infecções Sexualmente Transmissíveis/diagnóstico , Infecções Sexualmente Transmissíveis/epidemiologia , Infecções Sexualmente Transmissíveis/microbiologia , Chlamydia trachomatis , Neisseria gonorrhoeae , Alemanha , Reino Unido , Infecções por Mycoplasma/diagnóstico , Infecções por Mycoplasma/epidemiologia , Infecções por Mycoplasma/microbiologia , Gonorreia/microbiologia , Infecções por Chlamydia/diagnóstico
2.
Sex Transm Infect ; 97(1): 8-10, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32661071

RESUMO

OBJECTIVES: In recent years, resistance in Mycoplasma genitalium (MG) to first-line (azithromycin) and second-line (moxifloxacin) treatment has been increasingly reported worldwide, however, no data regarding the south of Spain are available. METHODS: To determine resistance rates, MG-positive samples collected from June 2018 to June 2019 were analysed by sequencing the 23S rRNA and parC genes. RESULTS: A total of 77 patients (24 men having sex with men (MSM), 30 heterosexual men and 23 women) were included. Resistance-associated mutations against macrolide and fluoroquinolones were found in 36.4% (95% CI 25.7% to 48.1%) and 9.1% (95% CI 3.7% to 17.8%) of the patients, respectively. Being MSM and having had another STI in the last year were significantly associated with macrolide-resistant MG infection, while no associations were found with resistance to fluoroquinolones. CONCLUSIONS: Testing for resistance to first-line and second-line drugs against MG should be recommended for the general population and mandatory for the MSM population. We suggest that empiric azithromycin use for STI management should be avoided.


Assuntos
Antibacterianos/uso terapêutico , Azitromicina/uso terapêutico , Farmacorresistência Bacteriana/genética , Fluoroquinolonas/uso terapêutico , Macrolídeos/uso terapêutico , Moxifloxacina/uso terapêutico , Mycoplasma genitalium/efeitos dos fármacos , Adulto , DNA Topoisomerase IV , Feminino , Heterossexualidade , Homossexualidade Masculina , Humanos , Masculino , Mutação , RNA Ribossômico 23S , Análise de Sequência de DNA , Espanha/epidemiologia , Adulto Jovem
3.
Eur J Clin Microbiol Infect Dis ; 40(6): 1337-1342, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33492527

RESUMO

Nowadays, it is of utmost importance to use fully validated assays for molecular-based diagnosis. In the field of sexually transmitted disease (STD), Roche and Hologic provide assays for diagnosing Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Mycoplasma genitalium (MG), and Trichomonas vaginalis (TV). A total of 212 clinical samples were tested. Aptima® Combo 2 (detecting CT and NG), Aptima® M. genitalium and the Aptima® T. vaginalis on the Panther® system were compared to CoBAS® CT/NG and CoBAS® TV/MG running on the CoBAS® 6800 system. To solve the discrepancies, Allplex™ STI Essential assay (Seegene®) and/or Sanger DNA sequencing were used. The diagnostic performance was calculated by mean of the sensitivity and specificity parameters. Aptima® (sensitivity: 98.90%, specificity: 100%), CoBAS® (sensitivity 100%, specificity: 96.67%). The CoBAS® combo (CT/NG) failed detecting NG from an anal/rectum specimen, which is not included into the validated specimens of the assay. Aptima® combo 2 produced two false positives (CT and NG), not detected by the third tests. All the assays showed an optimal diagnostic capacity, meeting the requirements for IVD DNA-based assays. All products work optimally on automatic platforms, minimizing time and risk of contamination during handling.


Assuntos
Infecções por Chlamydia/diagnóstico , Chlamydia trachomatis/isolamento & purificação , Gonorreia/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Infecções por Mycoplasma/diagnóstico , Mycoplasma genitalium/isolamento & purificação , Neisseria gonorrhoeae/isolamento & purificação , Infecções Sexualmente Transmissíveis/diagnóstico , Adulto , Infecções por Chlamydia/microbiologia , Chlamydia trachomatis/genética , Feminino , Gonorreia/microbiologia , Humanos , Masculino , Infecções por Mycoplasma/microbiologia , Mycoplasma genitalium/genética , Neisseria gonorrhoeae/genética , Sensibilidade e Especificidade , Infecções Sexualmente Transmissíveis/microbiologia , Vaginite por Trichomonas/diagnóstico , Vaginite por Trichomonas/microbiologia , Trichomonas vaginalis/genética , Trichomonas vaginalis/isolamento & purificação , Adulto Jovem
4.
Eur J Clin Microbiol Infect Dis ; 39(2): 235-241, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31902016

RESUMO

Pathogens causing sexually transmitted diseases (STDs) include viruses, bacteria, and parasites. The ability to rapidly and efficiently detect these pathogens in a single reaction still remains a health challenge. The aim of this study was to evaluate the clinical reliability and accuracy of the STD Direct Flow Chip Kit (Vitro, IVD-EC approved), which can simultaneously detect up to 9 different species of STD pathogens at once. This kit enables direct analysis-direct-PCR-of clinical specimens (urine, semen, endocervical, urethral, nasopharyngeal, and perianal swabs) without DNA purification for the following pathogens: Chlamydia trachomatis (serovars A-K and L1-L3), Haemophilus ducreyi, Herpes Simplex Virus (Types I and II), Mycoplasma genitalium, Mycoplasma hominis, Neisseria gonorrhoeae, Treponema pallidum, Trichomonas vaginalis, and Ureaplasma. The Anyplex™ II STI-7 Detection Kit (Seegene, IVD-EC) was used as the reference's method. Existing discordances were resolved using either a third molecular assay or DNA sequencing. Clinical performance was evaluated at two different stages: (i) from purified DNA of three hundred and fifty-eight clinical specimens with a diagnostic sensitivity (SE) and specificity (SP) of 99.4% and 100%, respectively, and an agreement of 99% (kappa index, κ = 0.97) with the reference's method and; (ii) by direct-PCR from six hundred and thirty-three specimens rendering SE, SP, and agreement values of 98.4%, 99.9%, and 98.0% (κ = 0.95), respectively. The STD Direct Flow Chip Kit constitutes a promising alternative to routine procedures in diagnostic, allowing direct analysis of specimens and enabling the detection of a broad panel of pathogens.


Assuntos
Reação em Cadeia da Polimerase Multiplex/métodos , Kit de Reagentes para Diagnóstico , Infecções Sexualmente Transmissíveis/diagnóstico , Infecções Sexualmente Transmissíveis/etiologia , Feminino , Humanos , Masculino , Reação em Cadeia da Polimerase Multiplex/normas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
5.
Int J Cancer ; 133(10): 2315-24, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-23681936

RESUMO

The extracellular protease ADAMTS1 (A disintegrin and metalloprotease with thrombospondin repeats 1) has been described as an anti-angiogenic molecule and its role as a putative tumor protective molecule has also been suggested. Here, we have used a tumor xenograft model to determine the role of ADAMTS1 in tumor growth and angiogenesis. Increasing levels of the protease led to the complete inhibition of tumor growth. In an attempt to elucidate the mechanism of action of this protease, we focused our attention on its proteolytic activity on nidogens, one of the main components of the vascular basement membrane. The increased expression of ADAMTS1 was accompanied by increased proteolysis of nidogen-1 and -2 and their almost complete removal from vascular structures, together with major morphological alterations of tumor blood vessels and a decreased vessel density. The clinical relevance of this work is supported by our observations that ADAMTS1 expression is decreased in breast tumor specimens when compared with healthy tissue. Our studies also reveal that the cleavage of nidogen-1 and -2 is partially inhibited in human tumor samples. Moreover, the deposition of both nidogens surrounding vascular structures is drastically altered, implying a possible reduction in the maintenance of vessel integrity. Our studies reflect the requirement to explore the functional interactions between proteases and specific substrates in cancer biology.


Assuntos
Proteínas ADAM/metabolismo , Neoplasias da Mama/genética , Moléculas de Adesão Celular/metabolismo , Genes Supressores de Tumor , Glicoproteínas de Membrana/metabolismo , Peptídeo Hidrolases/metabolismo , Proteínas ADAM/genética , Proteína ADAMTS1 , Animais , Membrana Basal/metabolismo , Membrana Basal/patologia , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proteínas de Ligação ao Cálcio , Moléculas de Adesão Celular/genética , Linhagem Celular , Regulação para Baixo , Glicosaminoglicanos/genética , Glicosaminoglicanos/metabolismo , Glicosaminoglicanos/fisiologia , Células HEK293 , Humanos , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos BALB C , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Proteólise , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo
6.
J Biol Chem ; 286(24): 21154-63, 2011 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-21521690

RESUMO

Excision of the bacterial group II intron RmInt1 has been demonstrated in vivo, resulting in the formation of both intron lariat and putative intron RNA circles. We show here that the bulged adenosine in domain VI of RmInt1 is required for splicing via the branching pathway, but branch site mutants produce small numbers of RNA molecules in which the first G residue of the intron is linked to the last C residue. Mutations in the coordination loop in domain I reduced splicing efficiency, but branched templates clearly predominated among splicing products. We also found that a single substitution at the EBS3 position (G329C), preventing EBS3-IBS3 pairing, resulted in the production of 50 to 100 times more RNA molecules in which the 5' and 3' extremities were joined. We provide evidence that these intron molecules may correspond to both, intron circles linked by a 2'-5' phosphodiester bond, and tandem, head-to-tail intron copies.


Assuntos
Adenosina/química , Íntrons , Sinorhizobium meliloti/metabolismo , Sequência de Bases , Sítios de Ligação , Éxons , Genes Bacterianos , Dados de Sequência Molecular , Mutação , Conformação de Ácido Nucleico , Splicing de RNA , RNA Bacteriano , RNA Catalítico/química , Elementos Reguladores de Transcrição , Ribonucleoproteínas/genética
7.
BMC Mol Biol ; 12: 24, 2011 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-21605368

RESUMO

BACKGROUND: Group II intron splicing proceeds through two sequential transesterification reactions in which the 5' and 3'-exons are joined together and the lariat intron is released. The intron-encoded protein (IEP) assists the splicing of the intron in vivo and remains bound to the excised intron lariat RNA in a ribonucleoprotein particle (RNP) that promotes intron mobility. Exon recognition occurs through base-pairing interactions between two guide sequences on the ribozyme domain dI known as EBS1 and EBS2 and two stretches of sequence known as IBS1 and IBS2 on the 5' exon, whereas the 3' exon is recognized through interaction with the sequence immediately upstream from EBS1 [(δ-δ' interaction (subgroup IIA)] or with a nucleotide [(EBS3-IBS3 interaction (subgroup IIB and IIC))] located in the coordination-loop of dI. The δ nucleotide is involved in base pairing with another intron residue (δ') in subgroup IIB introns and this interaction facilitates base pairing between the 5' exon and the intron. RESULTS: In this study, we investigated nucleotide requirements in the distal 5'- and 3' exon regions, EBS-IBS interactions and δ-δ' pairing for excision of the group IIB intron RmInt1 in vivo. We found that the EBS1-IBS1 interaction was required and sufficient for RmInt1 excision. In addition, we provide evidence for the occurrence of canonical δ-δ' pairing and its importance for the intron excision in vivo. CONCLUSIONS: The excision in vivo of the RmInt1 intron is a favored process, with very few constraints for sequence recognition in both the 5' and 3'-exons. Our results contribute to understand how group II introns spread in nature, and might facilitate the use of RmInt1 in gene targeting.


Assuntos
Éxons , RNA Bacteriano/metabolismo , RNA Catalítico/metabolismo , Sinorhizobium meliloti/genética , Pareamento de Bases , Sequência de Bases , Íntrons , Mutação , Conformação de Ácido Nucleico , Splicing de RNA , RNA Bacteriano/genética , RNA Catalítico/genética , Sinorhizobium meliloti/metabolismo
8.
Appl Environ Microbiol ; 77(3): 854-61, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21115708

RESUMO

The group IIA intron Ll.LtrB from Lactococcus lactis and the group IIB intron EcI5 from Escherichia coli have intron-encoded proteins (IEP) with a DNA-binding domain (D) and an endonuclease domain (En). Both have been successfully retargeted to invade target DNAs other than their wild-type target sites. RmInt1, a subclass IIB3/D intron with an IEP lacking D and En domains, is highly active in retrohoming in its host, Sinorhizobium meliloti. We found that RmInt1 was also mobile in E. coli and that retrohoming in this heterologous host depended on temperature, being more efficient at 28°C than at 37°C. Furthermore, we programmed RmInt1 to recognize target sites other than its wild-type site. These retargeted introns efficiently and specifically retrohome into a recipient plasmid target site or a target site present as a single copy in the chromosome, generating a mutation in the targeted gene. Our results extend the range of group II introns available for gene targeting.


Assuntos
Endonucleases/genética , Marcação de Genes , Inteínas/genética , Íntrons/genética , Estrutura Terciária de Proteína/genética , Sequência de Bases , DNA Bacteriano/genética , Escherichia coli/genética , Lactococcus lactis/genética , Dados de Sequência Molecular , Mutagênese Insercional , Plasmídeos , Sinorhizobium meliloti/genética
9.
Nutrients ; 12(2)2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-32041107

RESUMO

The vaginal microbiota has importance in preserving vaginal health and defending the host against disease. The advent of new molecular techniques and computer science has allowed researchers to discover microbial composition in depth and associate the structure of vaginal microbial communities. There is a consensus that vaginal flora is grouped into a restricted number of communities, although the structure of the community is constantly changing. Certain Community-Sate Types (CSTs) are more associated with poor reproductive outcomes and sexually transmitted diseases (STDs) meanwhile, CSTs dominated by Lactobacillus species-particularly Lactobacillus crispatus-are more related to vaginal health. In this work, we have reviewed how modifiable and non-modifiable factors may affect normal vaginal microbiota homeostasis-including sexual behavior, race or ethnicity, and hygiene. Special interest has been given to how the use of probiotics, diet intake, and use of hormone replacement therapies (HRTs) can potentially impact vaginal microbiota composition.


Assuntos
Disbiose , Microbiota , Vigna/microbiologia , Vigna/fisiologia , Ingestão de Alimentos , Feminino , Homeostase , Terapia de Reposição Hormonal , Humanos , Lactobacillus crispatus , Probióticos , Fatores de Risco , Vaginose Bacteriana/microbiologia
10.
Cancers (Basel) ; 12(4)2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32230715

RESUMO

Extracellular matrix remodeling within the tumor microenvironment has been recognized as a relevant dynamic framework during tumor growth. However, research on proteases that trigger this remodeling keeps revealing a wide range of actions including both pro- and anti-tumorigenic. The extracellular protease ADAMTS1 exemplifies this dual role. In this work, we first confirmed a positive correlation of ADAMTS1 with endothelial-like phenotype of human melanoma cells together with the finding of associated signatures, including key genes such as endothelial CDH5. Using a CRISPR-Cas9 approach, we observed that the inhibition of ADAMTS1 in an aggressive uveal melanoma model compromised its endothelial-like properties, and more importantly, caused a robust blockade on the progression of tumor xenografts. Although vasculature emerged affected in ADAMTS1-deficient tumors, the most relevant action implied the downregulation of endothelial CDH5 in tumor cells, in association with stemness markers. Indeed, melanoma sphere assays also revealed a deficient commitment to form spheres in the absence of ADAMTS1, directly correlating with stemness markers and, remarkably, also with CDH5. Finally, taking advantage of advanced bioinformatics tools and available public data of uveal melanomas, we disclosed new prognosis factors, including endothelial elements and ADAMTS proteases. Our findings support the key role of ADAMTS proteases for uveal melanoma development since earlier stages, modulating the complex crosstalk between extracellular matrix and the induction of stemness and endothelial-like features. To our knowledge, this is the first report that supports the development of therapeutic targets on the extracellular matrix to overcome uveal melanoma.

11.
PLoS One ; 14(9): e0222439, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31513653

RESUMO

Sexually transmitted infections (STIs) remain a worldwide problem and a severe threat to public health. The purpose of this study was to compare Aptima® Assays (Hologic®) and the Allplex™ STI Essential Assay (Seegene®) for the simultaneous detection of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis and Mycoplasma genitalium in clinical practice. The Aptima® assays (Hologic®) are based on a transcription-mediated amplification (TMA) method. The Allplex™ STI Essential assay (Seegene®) is based on a multiplex Real-Time PCR (RT-PCR) method. A total of 622 clinical samples from different anatomical sites were tested using both methods. A total of 88 (14.1%) and 66 (10.6%) positive samples were found for any of the TMA assays used and for the RT-PCR assay, respectively. Aptima® assays showed a slightly higher rate of positive results for all pathogens except for T. vaginalis, the results of which were similar to those obtained with Allplex™. The most commonly detected pathogen was C. trachomatis (37 samples; 5.9% using TMA assays) and the anatomical site with the highest prevalence of microorganisms was a non-urogenital site, the pharynx (27 positive samples; 4.3%). Using the Aptima® assays as reference method, the comparison showed that the average specificity of multiplex RT-PCR was 100.0% for the four pathogens. However an average sensitivity of 74.5% was observed, showing 95.2% (CI95%; 93.6-96.9) of overall concordance (κ = 0.80). In conclusion, the Aptima® assays show a higher sensitivity on a wide range of sample types compared to the Allplex™ assay.


Assuntos
Reação em Cadeia da Polimerase Multiplex/métodos , Infecções Sexualmente Transmissíveis/diagnóstico , Infecções Sexualmente Transmissíveis/epidemiologia , Adulto , Infecções por Chlamydia/diagnóstico , Chlamydia trachomatis , Feminino , Gonorreia/diagnóstico , Humanos , Masculino , Infecções por Mycoplasma/diagnóstico , Mycoplasma genitalium , Neisseria gonorrhoeae , Prevalência , Reação em Cadeia da Polimerase em Tempo Real/métodos , Sensibilidade e Especificidade , Espanha , Vaginite por Trichomonas/diagnóstico , Trichomonas vaginalis , Adulto Jovem
12.
Nucleic Acids Res ; 32(9): 2880-8, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15155857

RESUMO

Sinorhizobium meliloti RmInt1 is an efficient mobile group II intron that uses an unknown reverse transcriptase priming mechanism as the intron ribonucleoprotein complex can reverse splice into DNA target substrates but cannot carry out site-specific second strand cleavage due to the lack of a C-terminal DNA endonuclease domain. We show here that, like other mobile group II introns, RmInt1 moves around by an efficient RNA-based retrohoming mechanism. We found evidence of two distinct RmInt1 retrohoming pathways for mobility depending on the orientation of the target site relative to the direction of DNA replication. The preferred retrohoming pathway is consistent with reverse splicing of the intron RNA into single-stranded DNA at a replication fork, using a nascent lagging DNA strand as the primer for reverse transcription. This strand bias is the opposite of that reported for mobility of the lactococcal Ll.ltrB intron in the absence of second strand cleavage. The mobility mechanism found here for RmInt1 may be used for dissemination by many bacterial group II introns encoding proteins lacking the DNA endonuclease domain.


Assuntos
Íntrons , Retroelementos , Sinorhizobium meliloti/genética , Replicação do DNA , Modelos Genéticos , Mutagênese Insercional , RNA Bacteriano/genética , Moldes Genéticos , Transcrição Gênica
13.
J Mol Biol ; 326(2): 413-23, 2003 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-12559910

RESUMO

Group II intron-encoded proteins (IEPs), which have maturase and reverse transcriptase activities, form a ribonucleoprotein (RNP) complex with the intron RNA. Some IEPs also have a C-terminal DNA-binding region and conserved DNA endonuclease domain involved in the recognition and cleavage of specific DNA target sites used for intron homing. RmInt1 is a mobile group II intron of Sinorhizobium meliloti, the IEP of which lacks the endonuclease domain, as do over half of their bacterial counterparts. Here, we analyzed the DNA target sequence requirements for homing in vivo of intron RmInt1 and compared these requirements to those established for the Lactococcus lactis Ll.LtrB intron, a representative of mobile subgroup IIA introns encoding proteins with functional C-terminal DNA endonuclease domains. As for Ll.LtrB, RmInt1 homing requires modifiable base-pairing interactions between the intron RNA and the DNA target, involving 13 nucleotides. However, instead of the delta-delta' interaction, typical of subgroup IIA introns, we demonstrate that RmInt1 recognizes the first nucleotide within the 3' exon of the target site by a new EBS3/IBS3 pairing predicted for subgroup IIB self-splicing introns. Unlike Ll.LtrB, there are less stringent requirements for RmInt1 recognition of distal 5' and 3' exon regions, where only single nucleotide positions are fixed constraints for intron homing. Our results predict differences in the DNA target-site requirements among group II introns, which may have mechanistic and evolutionary implications.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Elementos de DNA Transponíveis , DNA Bacteriano/genética , Éxons , Íntrons , Sinorhizobium meliloti/genética , Pareamento de Bases , Sequência de Bases , DNA Bacteriano/química , DNA Bacteriano/metabolismo , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Plasmídeos/genética , RNA Bacteriano/química , RNA Bacteriano/genética , RNA Bacteriano/metabolismo , Recombinação Genética , Rhizobium/genética
14.
Int J Nanomedicine ; 9: 4277-91, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25246785

RESUMO

The clinical management of bone defects caused by trauma or nonunion fractures remains a challenge in orthopedic practice due to the poor integration and biocompatibility properties of the scaffold or implant material. In the current work, the osteogenic properties of carboxyl-modified single-walled carbon nanotubes (COOH-SWCNTs) were investigated in vivo and in vitro. When human preosteoblasts and murine embryonic stem cells were cultured on coverslips sprayed with COOH-SWCNTs, accelerated osteogenic differentiation was manifested by increased expression of classical bone marker genes and an increase in the secretion of osteocalcin, in addition to prior mineralization of the extracellular matrix. These results predicated COOH-SWCNTs' use to further promote osteogenic differentiation in vivo. In contrast, both cell lines had difficulties adhering to multi-walled carbon nanotube-based scaffolds, as shown by scanning electron microscopy. While a suspension of SWCNTs caused cytotoxicity in both cell lines at levels >20 µg/mL, these levels were never achieved by release from sprayed SWCNTs, warranting the approach taken. In vivo, human allografts formed by the combination of demineralized bone matrix or cartilage particles with SWCNTs were implanted into nude rats, and ectopic bone formation was analyzed. Histological analysis of both types of implants showed high permeability and pore connectivity of the carbon nanotube-soaked implants. Numerous vascularization channels appeared in the formed tissue, additional progenitor cells were recruited, and areas of de novo ossification were found 4 weeks post-implantation. Induction of the expression of bone-related genes and the presence of secreted osteopontin protein were also confirmed by quantitative polymerase chain reaction analysis and immunofluorescence, respectively. In summary, these results are in line with prior contributions that highlight the suitability of SWCNTs as scaffolds with high bone-inducing capabilities both in vitro and in vivo, confirming them as alternatives to current bone-repair therapies.


Assuntos
Materiais Biocompatíveis , Diferenciação Celular/efeitos dos fármacos , Nanotubos de Carbono , Osteogênese/efeitos dos fármacos , Aloenxertos , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/toxicidade , Linhagem Celular , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Nanotubos de Carbono/química , Nanotubos de Carbono/toxicidade , Osteoblastos/efeitos dos fármacos , Ratos , Ratos Nus
15.
J Alzheimers Dis ; 29(1): 51-62, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22207005

RESUMO

Brain clearance of amyloid-ß (Aß42) by innate immune cells is necessary for maintenance of normal brain function. Phagocytosis of soluble Aß42 by Alzheimer's disease (AD) macrophages is defective, recovered in all "Type I and Type II" AD patients by 1α,25(OH)2-vitamin D3 (1,25D3) and blocked by the nuclear vitamin D receptor (VDR) antagonist (23S)-25-dehydro-1α(OH)-vitamin D3-26,23-lactone (MK). Bisdemethoxycurcumin (BDC) is a VDR ligand and additive with 1,25D3 in promoting Aß42 phagocytosis by Type I, but not by Type II macrophages. Here, we define the following intracellular mechanisms regulated by 1,25D3 that are associated with recovery of phagocytosis and consistent with the selectivity of BDC: 1) 1,25D3 potentiates a 4,4-diisothiocyanostilbene-2,2-disulfonic acid-sensitive chloride channel (i.e., ClC-3) currents in both Type I and II AD macrophages, but curcumin only potentiates the currents in Type I cells; 2) 1,25D3 is particularly effective in upregulating ClC-3 mRNA expression in Type II peripheral blood mononuclear cells (PBMCs) while both 1,25D3 and the BDC analog, C180, upregulate VDR mRNA, repressed by Aß42 in Type II PBMCs; and 3) 1,25D3-induced Aß42 phagocytosis is attenuated by the calcium-dependent ClC-3 blocker, inositol 3,4,5,6-tetraphosphate (IP4), in both AD Types and by the MEK1/2 inhibitor U0126 only in Type II macrophages. VDR hydrogen/deuterium exchange coupled mass spectrometry and computational results show differences between the abilities of 1,25D3 and curcuminoids to stabilize VDR helices associated with the regulation of gene transcription. The structure-function results provide evidence that 1,25D3 activation of VDR-dependent genomic and nongenomic signaling, work in concert to recover dysregulated innate immune function in AD.


Assuntos
Doença de Alzheimer/imunologia , Peptídeos beta-Amiloides/imunologia , Calcitriol/farmacologia , Genoma , Macrófagos/imunologia , Fagocitose , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/genética , Calcitriol/química , Células Cultivadas , Regulação da Expressão Gênica , Humanos , Macrófagos/efeitos dos fármacos , Estrutura Secundária de Proteína , Transdução de Sinais
16.
Mol Endocrinol ; 25(8): 1289-300, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21659475

RESUMO

We have postulated that the vitamin D receptor (VDR) contains two overlapping ligand binding sites, a genomic pocket and an alternative pocket (AP), that mediate regulation of gene transcription and rapid responses, respectively. Flexible VDR + ligand docking calculations predict that the major blood metabolite, 25(OH)-vitamin D(3) (25D3), and curcumin (CM) bind more selectively to the VDR-AP when compared with the seco-steroid hormone 1α,25(OH)(2)-vitamin D(3) (1,25D3). In VDR wild-type-transfected COS-1 cells and TM4 Sertoli cells, 1,25D3, 25D3, and CM each trigger voltage-gated, outwardly rectifying chloride channel (ORCC) currents that can be blocked by the VDR antagonist 1ß,25(OH)(2)-vitamin D(3) and the chloride channel antagonist (4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid). VDR mutational analysis in transfected COS-1 cells demonstrate the DNA-binding domain is not, but the ligand binding and hinge domains of the VDR are, required for 1,25D3 and 25D3 to activate the ORCC. Dose-response studies demonstrate that 25D3 and 1,25D3 are approximately equipotent in stimulating ORCC rapid responses, whereas 1 nm 1,25D3 was 1000-fold more potent than 25D3 and CM in stimulating gene expression. The VDR-AP agonist effects of 1,25D3, 25D3, and low-dose CM are lost after pretreatment of TM4 cells with VDR small interfering RNA. Collectively, these results are consistent with an essential role for the VDR-AP in initiating the signaling required for rapid opening of ORCC. The fact that 25D3 is equipotent to 1,25D3 in opening ORCC suggests that reconsideration of the ability of 25D3 to generate biological responses in vivo may be in order.


Assuntos
Canais de Cloreto/metabolismo , Ativação do Canal Iônico , Receptores de Calcitriol/metabolismo , Animais , Sítios de Ligação , Células COS , Calcifediol/farmacologia , Chlorocebus aethiops , Curcumina/farmacologia , Sinergismo Farmacológico , Ergosterol/farmacologia , Genoma/genética , Humanos , Ativação do Canal Iônico/efeitos dos fármacos , Ligantes , Masculino , Modelos Moleculares , Estrutura Terciária de Proteína , Receptores de Calcitriol/química , Células de Sertoli/efeitos dos fármacos , Células de Sertoli/metabolismo , Relação Estrutura-Atividade , Transfecção
17.
J Steroid Biochem Mol Biol ; 119(3-5): 127-34, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20156558

RESUMO

Sertoli cell secretory activities are highly dependent on ion channel functions and critical to spermatogenesis. The steroid hormone 1alpha,25(OH)2-vitamin D3 (1,25(OH)2-D3) stimulates exocytosis in different cell systems by activating a nongenotropic vitamin D receptor (VDR). Here, we described 1,25(OH)2-D3 stimulation of secretion via Cl(-) channel activation in the mouse immature Sertoli cell line TM4. 1,25(OH)2-D3 potentiation of chloride currents was dependent on hormone concentration, and correlated with a significant increase in whole-cell capacitance within 20-40 min. In addition, Cl(-) currents were potentiated by the nongenomic VDR agonist 1alpha,25(OH)2 lumisterol D3 (JN), while 1,25(OH)2-D3 potentiation of channels was suppressed by nongenomic VDR antagonist 1beta,25(OH)2-vitamin D3 (HL). Treatment of TM4 cells with PKC and PKA activators PMA and forskolin respectively, increased Cl(-) currents significantly, while PKC and PKA inhibitors Go6983 and H-89, respectively, abolished 1,25(OH)2-D3 stimulation of Cl(-) currents, suggesting phosphorylation pathways in 1,25(OH))2-D3 mediated channel responses. RT-PCR demonstrated the expression of outwardly rectifying ClC-3 channels in TM4 cells. Taken together, our results demonstrate a PKA/PKC-dependent 1,25(OH)2-D3/VDR nongenotropic pathway leading to Cl(-) channel and exocytosis activation in Sertoli cells. We conclude that 1,25(OH)2-D3 appears to be a modulator of male reproductive functions at least in part by stimulating Sertoli cell secretory functions.


Assuntos
Calcitriol/farmacologia , Canais de Cloreto/metabolismo , Células de Sertoli/efeitos dos fármacos , Células de Sertoli/metabolismo , Adenilil Ciclases/metabolismo , Animais , Calcifediol/farmacologia , Calcitriol/análogos & derivados , Calcitriol/metabolismo , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Canais de Cloreto/antagonistas & inibidores , Canais de Cloreto/genética , AMP Cíclico/agonistas , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Ativadores de Enzimas/farmacologia , Exocitose/efeitos dos fármacos , Expressão Gênica , Ativação do Canal Iônico/efeitos dos fármacos , Masculino , Camundongos , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/metabolismo , RNA Mensageiro/metabolismo , Receptores de Calcitriol/agonistas , Receptores de Calcitriol/antagonistas & inibidores , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Células de Sertoli/patologia
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