Objective To evaluate the synergy of the Burkholderia signaling molecule cis-2-dodecenoic acid(BDSF) and fluconazole(FLU) or itraconazole(ITRA) against two azole-resistant C. albicans clinical isolates in vitro and in...Objective To evaluate the synergy of the Burkholderia signaling molecule cis-2-dodecenoic acid(BDSF) and fluconazole(FLU) or itraconazole(ITRA) against two azole-resistant C. albicans clinical isolates in vitro and in vivo. Methods Minimum inhibitory concentrations(MICs) of antibiotics against two azole-resistant C. albicans were measured by the checkerboard technique, E-test, and time-kill assay. In vivo antifungal synergy testing was performed on mice. Analysis of the relative gene expression levels of the strains was conducted by quantitative reverse-transcription polymerase chain reaction(qR T-PCR). Results BDSF showed highly synergistic effects in combination with FLU or ITRA with a fractional inhibitory concentration index of ≤ 0.08. BDSF was not cytotoxic to normal human foreskin fibroblast cells at concentrations of up to 300 μg/mL. The qR T-PCR results showed that the combination of BDSF and FLU/ITRA significantly inhibits the expression of the efflux pump genes CDR1 and MDR1 via suppression of the transcription factors TAC1 and MRR1, respectively, when compared with FLU or ITRA alone. No dramatic difference in the mR NA expression levels of ERG1, ERG11, and UPC2 was found, which indicates that the drug combinations do not significantly interfere with UPC2-mediated ergosterol levels. In vivo experiments revealed that combination therapy can be an effective therapeutic approach to treat candidiasis. Conclusion The synergistic effects of BDSF and azoles may be useful as an alternative approach to control azole-resistant Candida infections.展开更多
In accordance with previous reports, the sequences related to phosporylated protein segments occur in conserved variable domains of immunoglobulins including first of all certain N-terminally located segments. Consequ...In accordance with previous reports, the sequences related to phosporylated protein segments occur in conserved variable domains of immunoglobulins including first of all certain N-terminally located segments. Consequently, we look here for the sequences 1) composing human and mouse proteins different from antigen receptors, 2) identical with or highly similar to nucleotide sequence representatives of conserved variable immunoglobulin segments and 3) identical with or closely related to phosphorylation sites. More precisely, we searched for the corresponding actual pairs of DNA and protein sequence segments using five-step bilingual approach employing among others a) different types of BLAST searches, b) two in-principle-different machine-learning methods predicting phosphorylated sites and c) two large databases recording existing phosphorylation sites. The approach identified seven existing phosphorylation sites and thirty-seven related human and mouse segments achieving limits for several predictions or phylogenic parameters. Mostly serines phosporylated with ataxia-telangiectasia-related kinase (involved in regulation of DNA-double-strand-break repair) were indicated or predicted in this study. Hypermutation motifs, located in effective positions of the selected sequence segments, occurred significantly less frequently in transcribed than non-transcribed DNA strands suggesting thus the incidence of mutation events. In addition, marked differences between the numbers and proportions of human and mouse cancer-related sequence items were found in different steps of selection process. The possible role of hypermutation changes within the selected segments and the observed structural relationships are discussed here with respect to DNA damage, carcinogenesis, cancer vaccination, ageing and evolution. Taken together, our data represent additional and sometimes perhaps complementary information to the existing databases of empirically proven phosphorylation sites or pathogenically important spots.展开更多
Sequence similarities were found between protein and DNA sequences encoding certain part of conserved variable immunoglobulin domains (i.e. conserved IgV) and phosphorylation sites. Hypermutation motifs were then indi...Sequence similarities were found between protein and DNA sequences encoding certain part of conserved variable immunoglobulin domains (i.e. conserved IgV) and phosphorylation sites. Hypermutation motifs were then indicated in the majority of the corresponding non-IgV nucleotide sequences. According to database confirmations or double prediction of phosphorylation sites, 80% of the selected human and mouse IgV-related phosphorylation sites or their highly probable candidates exhibited substrate relationship to ataxia-telangiectasia-mutated kinase known as ATM. In accordance with literature data, inactivation of ATM by mutations can participate in the mechanisms of carcinogenesis, neurodegeneration and possibly also in aging. In agreement with this relationship, some of the selected IgV-/ATM-related segments formed molecules specifically involved in carcinogenesis. The selected IgV-related sequence segments were also similar to certain segments of higher plants containing immunoglobulin-like repeats and related regions. Bioinformatic analysis of some selected plant sequences then indicated the presence of catalytic domains composing serine/threonine/tyrosine receptor/receptor-like kinases, which are considered important structures for evolution of very early and part of later Ig-domain-related immunity. The analyzed conserved domain similarities also suggested certain interesting structural and phylogenic relationships, which need to be further investigated. This review in fact briefly summarizes the findings on the subject from the last twenty years.展开更多
基金financially supported by the National Natural Science Foundation of China [81273409]the Program for Changjiang Scholars and Innovative Research Team in University [IRT_15R37]the Ministry of Science and Technology of China [2017YFA0205301]
文摘Objective To evaluate the synergy of the Burkholderia signaling molecule cis-2-dodecenoic acid(BDSF) and fluconazole(FLU) or itraconazole(ITRA) against two azole-resistant C. albicans clinical isolates in vitro and in vivo. Methods Minimum inhibitory concentrations(MICs) of antibiotics against two azole-resistant C. albicans were measured by the checkerboard technique, E-test, and time-kill assay. In vivo antifungal synergy testing was performed on mice. Analysis of the relative gene expression levels of the strains was conducted by quantitative reverse-transcription polymerase chain reaction(qR T-PCR). Results BDSF showed highly synergistic effects in combination with FLU or ITRA with a fractional inhibitory concentration index of ≤ 0.08. BDSF was not cytotoxic to normal human foreskin fibroblast cells at concentrations of up to 300 μg/mL. The qR T-PCR results showed that the combination of BDSF and FLU/ITRA significantly inhibits the expression of the efflux pump genes CDR1 and MDR1 via suppression of the transcription factors TAC1 and MRR1, respectively, when compared with FLU or ITRA alone. No dramatic difference in the mR NA expression levels of ERG1, ERG11, and UPC2 was found, which indicates that the drug combinations do not significantly interfere with UPC2-mediated ergosterol levels. In vivo experiments revealed that combination therapy can be an effective therapeutic approach to treat candidiasis. Conclusion The synergistic effects of BDSF and azoles may be useful as an alternative approach to control azole-resistant Candida infections.
文摘In accordance with previous reports, the sequences related to phosporylated protein segments occur in conserved variable domains of immunoglobulins including first of all certain N-terminally located segments. Consequently, we look here for the sequences 1) composing human and mouse proteins different from antigen receptors, 2) identical with or highly similar to nucleotide sequence representatives of conserved variable immunoglobulin segments and 3) identical with or closely related to phosphorylation sites. More precisely, we searched for the corresponding actual pairs of DNA and protein sequence segments using five-step bilingual approach employing among others a) different types of BLAST searches, b) two in-principle-different machine-learning methods predicting phosphorylated sites and c) two large databases recording existing phosphorylation sites. The approach identified seven existing phosphorylation sites and thirty-seven related human and mouse segments achieving limits for several predictions or phylogenic parameters. Mostly serines phosporylated with ataxia-telangiectasia-related kinase (involved in regulation of DNA-double-strand-break repair) were indicated or predicted in this study. Hypermutation motifs, located in effective positions of the selected sequence segments, occurred significantly less frequently in transcribed than non-transcribed DNA strands suggesting thus the incidence of mutation events. In addition, marked differences between the numbers and proportions of human and mouse cancer-related sequence items were found in different steps of selection process. The possible role of hypermutation changes within the selected segments and the observed structural relationships are discussed here with respect to DNA damage, carcinogenesis, cancer vaccination, ageing and evolution. Taken together, our data represent additional and sometimes perhaps complementary information to the existing databases of empirically proven phosphorylation sites or pathogenically important spots.
文摘Sequence similarities were found between protein and DNA sequences encoding certain part of conserved variable immunoglobulin domains (i.e. conserved IgV) and phosphorylation sites. Hypermutation motifs were then indicated in the majority of the corresponding non-IgV nucleotide sequences. According to database confirmations or double prediction of phosphorylation sites, 80% of the selected human and mouse IgV-related phosphorylation sites or their highly probable candidates exhibited substrate relationship to ataxia-telangiectasia-mutated kinase known as ATM. In accordance with literature data, inactivation of ATM by mutations can participate in the mechanisms of carcinogenesis, neurodegeneration and possibly also in aging. In agreement with this relationship, some of the selected IgV-/ATM-related segments formed molecules specifically involved in carcinogenesis. The selected IgV-related sequence segments were also similar to certain segments of higher plants containing immunoglobulin-like repeats and related regions. Bioinformatic analysis of some selected plant sequences then indicated the presence of catalytic domains composing serine/threonine/tyrosine receptor/receptor-like kinases, which are considered important structures for evolution of very early and part of later Ig-domain-related immunity. The analyzed conserved domain similarities also suggested certain interesting structural and phylogenic relationships, which need to be further investigated. This review in fact briefly summarizes the findings on the subject from the last twenty years.
