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1.
mBio ; 11(2)2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32345638

RESUMO

The capacity of Candida albicans to reversibly change its morphology between yeast and filamentous stages is crucial for its virulence. Formation of hyphae correlates with the upregulation of genes ALS3 and ECE1, which are involved in pathogenicity processes such as invasion, iron acquisition, and host cell damage. The global repressor Tup1 and its cofactor Nrg1 are considered to be the main antagonists of hyphal development in C. albicans However, our experiments revealed that Tup1, but not Nrg1, was required for full expression of ALS3 and ECE1 In contrast to NRG1, overexpression of TUP1 was found to inhibit neither filamentous growth nor transcription of ALS3 and ECE1 In addition, we identified the transcription factor Ahr1 as being required for full expression of both genes. A hyperactive version of Ahr1 bound directly to the promoters of ALS3 and ECE1 and induced their transcription even in the absence of environmental stimuli. This regulation worked even in the absence of the crucial hyphal growth regulators Cph1 and Efg1 but was dependent on the presence of Tup1. Overall, our results show that Ahr1 and Tup1 are key contributors in the complex regulation of virulence-associated genes in the different C. albicans morphologies.IMPORTANCE Candida albicans is a major human fungal pathogen and the leading cause of systemic Candida infections. In recent years, Als3 and Ece1 were identified as important factors for fungal virulence. Transcription of both corresponding genes is closely associated with hyphal growth. Here, we describe how Tup1, normally a global repressor of gene expression as well as of filamentation, and the transcription factor Ahr1 contribute to full expression of ALS3 and ECE1 in C. albicans hyphae. Both regulators are required for high mRNA amounts of the two genes to ensure functional relevant protein synthesis and localization. These observations identified a new aspect of regulation in the complex transcriptional control of virulence-associated genes in C. albicans.

2.
J Hepatol ; 72(3): 391-400, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31606552

RESUMO

BACKGROUND & AIMS: Alcohol-associated liver disease is a leading indication for liver transplantation and a leading cause of mortality. Alterations to the gut microbiota contribute to the pathogenesis of alcohol-associated liver disease. Patients with alcohol-associated liver disease have increased proportions of Candida spp. in the fecal mycobiome, yet little is known about the effect of intestinal Candida on the disease. Herein, we evaluated the contributions of Candida albicans and its exotoxin candidalysin in alcohol-associated liver disease. METHODS: C. albicans and the extent of cell elongation 1 (ECE1) were analyzed in fecal samples from controls, patients with alcohol use disorder and those with alcoholic hepatitis. Mice colonized with different and genetically manipulated C. albicans strains were subjected to the chronic-plus-binge ethanol diet model. Primary hepatocytes were isolated and incubated with candidalysin. RESULTS: The percentages of individuals carrying ECE1 were 0%, 4.76% and 30.77% in non-alcoholic controls, patients with alcohol use disorder and patients with alcoholic hepatitis, respectively. Candidalysin exacerbates ethanol-induced liver disease and is associated with increased mortality in mice. Candidalysin enhances ethanol-induced liver disease independently of the ß-glucan receptor C-type lectin domain family 7 member A (CLEC7A) on bone marrow-derived cells, and candidalysin does not alter gut barrier function. Candidalysin can damage primary hepatocytes in a dose-dependent manner in vitro and is associated with liver disease severity and mortality in patients with alcoholic hepatitis. CONCLUSIONS: Candidalysin is associated with the progression of ethanol-induced liver disease in preclinical models and worse clinical outcomes in patients with alcoholic hepatitis. LAY SUMMARY: Candidalysin is a peptide toxin secreted by the commensal gut fungus Candida albicans. Candidalysin enhances alcohol-associated liver disease independently of the ß-glucan receptor CLEC7A on bone marrow-derived cells in mice without affecting intestinal permeability. Candidalysin is cytotoxic to primary hepatocytes, indicating a direct role of candidalysin on ethanol-induced liver disease. Candidalysin might be an effective target for therapy in patients with alcohol-associated liver disease.

3.
Trends Microbiol ; 27(12): 982-996, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31451347

RESUMO

Dysbiosis in the female genital tract (FGT) is characterized by the overgrowth of pathogenic bacterial, fungal, or protozoan members of the microbiota, leading to symptomatic or asymptomatic infections. In this review, we discuss recent advances in studies dealing with molecular mechanisms of pathogenicity factors of Gardnerella vaginalis, Mycoplasma genitalium, Mycoplasma hominis, Neisseria gonorrhoeae, Streptococcus agalactiae, Chlamydia trachomatis, Trichomonas vaginalis, and Candida spp., as well as their interactions with the host and microbiota in the various niches of the FGT. Taking a holistic approach to identifying fundamental commonalities and differences during these infections could help us to better understand reproductive tract health and improve current prevention and treatment strategies.

4.
mBio ; 9(5)2018 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-30206168

RESUMO

Macrophages rely on phagosomal acidity to destroy engulfed microorganisms. To survive this hostile response, opportunistic fungi such as Candida albicans developed strategies to evade the acidic environment. C. albicans is polymorphic and able to convert from yeast to hyphae, and this transition is required to subvert the microbicidal activity of the phagosome. However, the phagosomal lumen, which is acidic and nutrient deprived, is believed to inhibit the yeast-to-hypha transition. To account for this apparent paradox, it was recently proposed that C. albicans produces ammonia that alkalinizes the phagosome, thus facilitating yeast-to-hypha transition. We reexamined the mechanism underlying phagosomal alkalinization by applying dual-wavelength ratiometric pH measurements. The phagosomal membrane was found to be highly permeable to ammonia, which is therefore unlikely to account for the pH elevation. Instead, we find that yeast-to-hypha transition begins within acidic phagosomes and that alkalinization is a consequence of proton leakage induced by excessive membrane distension caused by the expanding hypha.IMPORTANCEC. albicans is the most common cause of nosocomial fungal infection, and over 3 million people acquire life-threatening invasive fungal infections every year. Even if antifungal drugs exist, almost half of these patients will die. Despite this, fungi remain underestimated as pathogens. Our study uses quantitative biophysical approaches to demonstrate that yeast-to-hypha transition occurs within the nutrient-deprived, acidic phagosome and that alkalinization is a consequence, as opposed to the cause, of hyphal growth.


Assuntos
Candida albicans/crescimento & desenvolvimento , Membranas Intracelulares/fisiologia , Fagossomos/química , Fagossomos/microbiologia , Animais , Concentração de Íons de Hidrogênio , Hifas/crescimento & desenvolvimento , Camundongos , Permeabilidade , Fagossomos/fisiologia , Células RAW 264.7
5.
mBio ; 9(3)2018 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-29871918

RESUMO

Life-threatening systemic infections often occur due to the translocation of pathogens across the gut barrier and into the bloodstream. While the microbial and host mechanisms permitting bacterial gut translocation are well characterized, these mechanisms are still unclear for fungal pathogens such as Candida albicans, a leading cause of nosocomial fungal bloodstream infections. In this study, we dissected the cellular mechanisms of translocation of C. albicans across intestinal epithelia in vitro and identified fungal genes associated with this process. We show that fungal translocation is a dynamic process initiated by invasion and followed by cellular damage and loss of epithelial integrity. A screen of >2,000 C. albicans deletion mutants identified genes required for cellular damage of and translocation across enterocytes. Correlation analysis suggests that hypha formation, barrier damage above a minimum threshold level, and a decreased epithelial integrity are required for efficient fungal translocation. Translocation occurs predominantly via a transcellular route, which is associated with fungus-induced necrotic epithelial damage, but not apoptotic cell death. The cytolytic peptide toxin of C. albicans, candidalysin, was found to be essential for damage of enterocytes and was a key factor in subsequent fungal translocation, suggesting that transcellular translocation of C. albicans through intestinal layers is mediated by candidalysin. However, fungal invasion and low-level translocation can also occur via non-transcellular routes in a candidalysin-independent manner. This is the first study showing translocation of a human-pathogenic fungus across the intestinal barrier being mediated by a peptide toxin.IMPORTANCECandida albicans, usually a harmless fungus colonizing human mucosae, can cause lethal bloodstream infections when it manages to translocate across the intestinal epithelium. This can result from antibiotic treatment, immune dysfunction, or intestinal damage (e.g., during surgery). However, fungal processes may also contribute. In this study, we investigated the translocation process of C. albicans using in vitro cell culture models. Translocation occurs as a stepwise process starting with invasion, followed by epithelial damage and loss of epithelial integrity. The ability to secrete candidalysin, a peptide toxin deriving from the hyphal protein Ece1, is key: C. albicans hyphae, secreting candidalysin, take advantage of a necrotic weakened epithelium to translocate through the intestinal layer.


Assuntos
Candida albicans/fisiologia , Candidíase/microbiologia , Células Epiteliais/microbiologia , Mucosa Intestinal/microbiologia , Intestinos/microbiologia , Apoptose , Candida albicans/genética , Candidíase/fisiopatologia , Enterócitos/citologia , Enterócitos/microbiologia , Células Epiteliais/citologia , Interações Hospedeiro-Patógeno , Humanos , Mucosa Intestinal/citologia , Intestinos/citologia
6.
Appl Microbiol Biotechnol ; 102(4): 1889-1901, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29330691

RESUMO

Candida spp. are leading causes of opportunistic mycoses, including life-threatening hospital-borne infections, and novel antifungals, preferably aiming targets that have not been used before, are constantly needed. Hydrazone- and guanidine-containing molecules have shown a wide range of biological activities, including recently described excellent antifungal properties. In this study, four bis-guanylhydrazone derivatives (BG1-4) were generated following a previously developed synthetic route. Anti-Candida (two C. albicans, C. glabrata, and C. parapsilosis) minimal inhibitory concentrations (MICs) of bis-guanylhydrazones were between 2 and 15.6 µg/mL. They were also effective against preformed 48-h-old C. albicans biofilms. In vitro DNA interaction, circular dichroism, and molecular docking analysis showed the great ability of these compounds to bind fungal DNA. Competition with DNA-binding stain, exposure of phosphatidylserine at the outer layer of the cytoplasmic membrane, and activation of metacaspases were shown for BG3. This pro-apoptotic effect of BG3 was only partially due to the accumulation of reactive oxygen species in C. albicans, as only twofold MIC and higher concentrations of BG3 caused depolarization of mitochondrial membrane which was accompanied by the decrease of the activity of fungal mitochondrial dehydrogenases, while the activity of oxidative stress response enzymes glutathione reductase and catalase was not significantly affected. BG3 showed synergistic activity with amphotericin B with a fractional inhibitory concentration index of 0.5. It also exerted low cytotoxicity and the ability to inhibit epithelial cell (TR146) invasion and damage by virulent C. albicans SC5314. With further developments, BG3 may further progress in the antifungal pipeline as a DNA-targeting agent.


Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , DNA Fúngico/efeitos dos fármacos , Guanidinas/farmacologia , Hidrazonas/farmacologia , Antifúngicos/síntese química , Apoptose , Candida/fisiologia , Dicroísmo Circular , Sinergismo Farmacológico , Guanidinas/síntese química , Hidrazonas/síntese química , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular
7.
mBio ; 9(1)2018 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-29362237

RESUMO

Candida albicans is an opportunistic fungal pathogen responsible for superficial and life-threatening infections in humans. During mucosal infection, C. albicans undergoes a morphological transition from yeast to invasive filamentous hyphae that secrete candidalysin, a 31-amino-acid peptide toxin required for virulence. Candidalysin damages epithelial cell plasma membranes and stimulates the activating protein 1 (AP-1) transcription factor c-Fos (via p38-mitogen-activated protein kinase [MAPK]), and the MAPK phosphatase MKP1 (via extracellular signal-regulated kinases 1 and 2 [ERK1/2]-MAPK), which trigger and regulate proinflammatory cytokine responses, respectively. The candidalysin toxin resides as a discrete cryptic sequence within a larger 271-amino-acid parental preproprotein, Ece1p. Here, we demonstrate that kexin-like proteinases, but not secreted aspartyl proteinases, initiate a two-step posttranslational processing of Ece1p to produce candidalysin. Kex2p-mediated proteolysis of Ece1p after Arg61 and Arg93, but not after other processing sites within Ece1p, is required to generate immature candidalysin from Ece1p, followed by Kex1p-mediated removal of a carboxyl arginine residue to generate mature candidalysin. C. albicans strains harboring mutations of Arg61 and/or Arg93 did not secrete candidalysin, were unable to induce epithelial damage and inflammatory responses in vitro, and showed attenuated virulence in vivo in a murine model of oropharyngeal candidiasis. These observations identify enzymatic processing of C. albicans Ece1p by kexin-like proteinases as crucial steps required for candidalysin production and fungal pathogenicity.IMPORTANCECandida albicans is an opportunistic fungal pathogen that causes mucosal infection in millions of individuals worldwide. Successful infection requires the secretion of candidalysin, the first cytolytic peptide toxin identified in any human fungal pathogen. Candidalysin is derived from its parent protein Ece1p. Here, we identify two key amino acids within Ece1p vital for processing and production of candidalysin. Mutations of these residues render C. albicans incapable of causing epithelial damage and markedly reduce mucosal infection in vivo Importantly, candidalysin production requires two individual enzymatic events. The first involves processing of Ece1p by Kex2p, yielding immature candidalysin, which is then further processed by Kex1p to produce the mature toxin. These observations identify important steps for C. albicans pathogenicity at mucosal surfaces.


Assuntos
Candida albicans/metabolismo , Carboxipeptidases/metabolismo , Proteínas Fúngicas/metabolismo , Pró-Proteína Convertases/metabolismo , Processamento de Proteína Pós-Traducional , Proteólise , Animais , Candida albicans/patogenicidade , Candidíase Bucal/microbiologia , Candidíase Bucal/patologia , Modelos Animais de Doenças , Camundongos , Virulência
8.
Microbiology ; 162(12): 2116-2125, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27902418

RESUMO

The glucocorticoid betamethasone (BM) is frequently employed in clinical practice because of its anti-inflammatory and immunosuppressive properties. In this study, we investigated the effect of BM (1 and 2 mM) on the ability of Candida albicans to adhere to, invade and damage oral, intestinal or vaginal epithelial cells, as well as to elicit cytokine and chemokine release. BM at 2 mM concentration stimulated adherence of C. albicans to vaginal cells and facilitated the invasion of intestinal and vaginal epithelia without influencing the growth rate of invading C. albicans hyphae at any type of epithelia and BM concentrations tested. In addition, BM at 2 mM concentration also augmented C. albicans-initiated cell damage of oral and intestinal cells. Furthermore, BM exposure decreased IL-6 cytokine and IL-8 chemokine release from oral and vaginal epithelial cells and also IL-6 release from intestinal epithelium after infection with C. albicans. These observations suggest that high-dose applications of BM may predispose patients to various epithelial C. albicans infections.


Assuntos
Betametasona/farmacologia , Candida albicans/efeitos dos fármacos , Candidíase/microbiologia , Células Epiteliais/microbiologia , Glucocorticoides/farmacologia , Candida albicans/crescimento & desenvolvimento , Candida albicans/fisiologia , Candidíase/metabolismo , Linhagem Celular , Células Epiteliais/metabolismo , Humanos , Interleucina-6/metabolismo , Interleucina-8/metabolismo
9.
Cell Microbiol ; 18(12): 1709-1715, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27552083

RESUMO

Candida albicans is an important human opportunistic fungal pathogen which is frequently found as part of the normal human microbiota. It is well accepted that the fungus interacts with other components of the resident microbiota and that this impacts the commensal or pathogenic outcome of C. albicans colonization. Different types of interactions, including synergism or antagonism, contribute to a complex balance between the multitude of different species. Mixed biofilms of C. albicans and streptococci are a well-studied example of a mutualistic interaction often potentiating the virulence of the individual members. In contrast, other bacteria like lactobacilli are known to antagonize C. albicans, and research has just started elucidating the mechanisms behind these interactions. This scenario is even more complicated by a third player, the host. This review focuses on interactions between C. albicans and gram-positive bacteria whose investigation will without doubt ultimately help understanding C. albicans infections.


Assuntos
Biofilmes/crescimento & desenvolvimento , Candida albicans/patogenicidade , Candidíase/imunologia , Bactérias Gram-Positivas/patogenicidade , Infecções por Bactérias Gram-Positivas/imunologia , Lactobacillaceae/patogenicidade , Antibiose/fisiologia , Aderência Bacteriana , Candida albicans/genética , Candida albicans/crescimento & desenvolvimento , Candidíase/microbiologia , Coinfecção , Bactérias Gram-Positivas/genética , Bactérias Gram-Positivas/crescimento & desenvolvimento , Infecções por Bactérias Gram-Positivas/microbiologia , Interações Hospedeiro-Patógeno , Humanos , Lactobacillaceae/genética , Lactobacillaceae/crescimento & desenvolvimento , Simbiose/fisiologia , Virulência
10.
Curr Opin Microbiol ; 32: 89-95, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27257746

RESUMO

Human fungal pathogens are a commonly underestimated cause of severe diseases associated with high morbidity and mortality. Like other pathogens, their survival and growth in the host, as well as subsequent host damage, is thought to be mediated by virulence factors which set them apart from harmless microbes. In this review, we describe and discuss commonly employed strategies for fungal survival and growth in the host and how these affect the host-fungus interactions to lead to disease. While many of these strategies require host-specific virulence factors, more generally any fitness factor which allows growth under host-like conditions can be required for pathogenesis. Furthermore, we briefly summarize how different fungal pathogens are thought to damage the host. We find that in addition to a core of common activities relevant for growth, different groups of fungi employ different strategies which in spite of (or together with) the host's response can lead to disease.


Assuntos
Fungos/crescimento & desenvolvimento , Fungos/patogenicidade , Interações Hospedeiro-Patógeno , Micoses/patologia , Humanos , Micoses/microbiologia , Fatores de Virulência
11.
Nature ; 532(7597): 64-8, 2016 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-27027296

RESUMO

Cytolytic proteins and peptide toxins are classical virulence factors of several bacterial pathogens which disrupt epithelial barrier function, damage cells and activate or modulate host immune responses. Such toxins have not been identified previously in human pathogenic fungi. Here we identify the first, to our knowledge, fungal cytolytic peptide toxin in the opportunistic pathogen Candida albicans. This secreted toxin directly damages epithelial membranes, triggers a danger response signalling pathway and activates epithelial immunity. Membrane permeabilization is enhanced by a positive charge at the carboxy terminus of the peptide, which triggers an inward current concomitant with calcium influx. C. albicans strains lacking this toxin do not activate or damage epithelial cells and are avirulent in animal models of mucosal infection. We propose the name 'Candidalysin' for this cytolytic peptide toxin; a newly identified, critical molecular determinant of epithelial damage and host recognition of the clinically important fungus, C. albicans.


Assuntos
Candida albicans/metabolismo , Candida albicans/patogenicidade , Citotoxinas/metabolismo , Proteínas Fúngicas/toxicidade , Micotoxinas/toxicidade , Fatores de Virulência/metabolismo , Cálcio/metabolismo , Candida albicans/imunologia , Candidíase/metabolismo , Candidíase/microbiologia , Candidíase/patologia , Permeabilidade da Membrana Celular/efeitos dos fármacos , Citotoxinas/genética , Citotoxinas/toxicidade , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/imunologia , Células Epiteliais/patologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Humanos , Membrana Mucosa/microbiologia , Membrana Mucosa/patologia , Micotoxinas/genética , Micotoxinas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Virulência/efeitos dos fármacos , Fatores de Virulência/genética , Fatores de Virulência/toxicidade
12.
J Microbiol ; 54(3): 149-69, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26920876

RESUMO

The interaction between Candida albicans and its host cells is characterized by a complex interplay between the expression of fungal virulence factors, which results in adherence, invasion and cell damage, and the host immune system, which responds by secreting proinflammatory cytokines, activating antimicrobial activities and killing the fungal pathogen. In this review we describe this interplay by taking a closer look at how C. albicans pathogenicity is induced and executed, how the host responds in order to prevent and clear an infection, and which mechanisms C. albicans has evolved to bypass these immune responses to avoid clearance. Furthermore, we review studies that show how the presence of other microorganisms affects this interplay.


Assuntos
Candida albicans/patogenicidade , Candidíase/microbiologia , Fatores de Virulência , Imunidade Adaptativa , Animais , Candida albicans/imunologia , Candidíase/imunologia , Candidíase/patologia , Candidíase/prevenção & controle , Interações Hospedeiro-Patógeno , Humanos , Evasão da Resposta Imune , Imunidade Inata/fisiologia , Fatores de Virulência/imunologia
13.
Pharmacol Res ; 103: 149-57, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26607863

RESUMO

Diabetic macular edema (DME) is a serious condition that can cause blindness in diabetic patients suffering from diabetic retinopathy (DR). Although vascular endothelial growth factor (VEGF) is known to play a role in the development of DME, the pathological processes leading to the onset of this disease are highly complex and the exact sequence in which they occur is still not completely understood. Angiogenesis and inflammation have been shown to be involved in the pathogenesis of this disease. However, it still remains to be clarified whether angiogenesis following VEGF over-expression is a cause or a consequence of inflammation. Here, we provide an overview of the current data available in the literature focusing on VEGF, angiogenesis, inflammation, DR and DME. Our analysis suggests that angiogenesis and inflammation act interdependently during the development of DME. VEGF is a critical player in the molecular crosstalk occurring between these two processes, reinforcing the use of anti-VEGF agents for the treatment of DME.


Assuntos
Edema Macular/metabolismo , Neovascularização Patológica/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Retinopatia Diabética/metabolismo , Retinopatia Diabética/patologia , Humanos , Edema Macular/patologia
14.
World J Gastroenterol ; 21(23): 7281-8, 2015 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-26109816

RESUMO

AIM: To confirm the efficacy and safety of bevacizumab/XELOX combination for the treatment of locally advanced or metastatic colorectal cancer (CRC) in Italy. METHODS: This multicentric, prospective, open-label study included patients with CRC previously untreated with chemotherapy. Patients were administered bevacizumab in combination with XELOX. The primary efficacy end-point was progression-free survival (PFS). Secondary end-points included time to overall response (TOR), duration of response (DOR), time to treatment failure (TTF) and overall survival (OS). The incidence and type of adverse events AEs and severe AEs were evaluated. Also, the mutational status of BRAF and KRAS was assessed by high resolution melting and direct sequencing, and quality of life (QoL) was measured by the EuroQoL EQ-5D questionnaire at baseline and at the last visit. RESULTS: The intention-to-treat population included 197 patients (mean age: 62.3 ± 9.9 years, 56.4% males). At baseline, 16/34 evaluable subjects (47.1%) harbored a KRAS and/or a BRAF mutation; the mean QoL index was 80.2 ± 14.3. First-line therapy was given for 223.7 ± 175.9 d, and after a mean follow-up of 387.7 ± 238.8 d all patients discontinued from the study mainly for disease progression (PD, 45.4%) and AEs (25.4%). Median PFS was 9.7 mo (95%CI: 8.4-10.5) and the median values for secondary end-points were: TOR = 3.9 mo (95%CI: 2.6-4.7), DOR = 8.5 mo (95%CI: 7.3-10.3), TTF = 6.7 mo (95%CI: 6.0-7.7) and OS = 23.2 mo (95%CI: 20.1-27.2). Patients carrying at least one lesion had a lower overall response rate (66.7% vs 88.9%) and a lower probability of achieving complete or partial response than those without mutations, but the difference in relative risk was not statistically significant (P = 0.2). Mean EQ-5D-3L raw index score significantly decreased to 74.9 ± 19.1 at the last visit (signed-rank test, P = 0.0076), but in general the evaluation on QoL perceived by patients was good. CONCLUSION: The efficacy of bevacizumab in combination with XELOX in terms of PFS in patients with aCRC or mCRC in Italy was confirmed, with acceptable toxicity.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Bevacizumab/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Desoxicitidina/análogos & derivados , Fluoruracila/análogos & derivados , Adulto , Idoso , Idoso de 80 Anos ou mais , Inibidores da Angiogênese/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Bevacizumab/efeitos adversos , Neoplasias Colorretais/genética , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Análise Mutacional de DNA , Desoxicitidina/efeitos adversos , Desoxicitidina/uso terapêutico , Progressão da Doença , Intervalo Livre de Doença , Feminino , Fluoruracila/efeitos adversos , Fluoruracila/uso terapêutico , Humanos , Análise de Intenção de Tratamento , Itália , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Mutação , Metástase Neoplásica , Estudos Prospectivos , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Qualidade de Vida , Fatores de Risco , Inquéritos e Questionários , Fatores de Tempo , Resultado do Tratamento
15.
Drug Des Devel Ther ; 8: 983-92, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25092964

RESUMO

BACKGROUND: Migraine is a painful neurological disorder that affects over 10% of the general population. Frovatriptan and rizatriptan are antimigraine agents belonging to the triptan class. Although previous studies have independently compared the efficacy of these agents, contemporaneous data examining both pharmacokinetic (PK) properties and efficacy in parallel have not previously been available. MATERIALS AND METHODS: In this single-center double-blind study, 18 subjects (ten female) were treated for a single migraine attack with frovatriptan 2.5 mg or rizatriptan 10 mg. Plasma concentrations were measured predose and at 2, 4, 6, 12, 24, 48, and 72 hours after drug administration. The primary end point of this study was to evaluate the association between PK parameters and efficacy measures and recurrence rate. Secondary end points were pain-free and pain-relief episodes at 2 and 4 hours, recurrent episodes within 48 hours, and cumulative hazard of recurrence within 72 hours. RESULTS: At baseline, approximately 17% of patients had mild migraine, while 83% had moderate-severe migraine. Although the time to maximum concentration was similar for both drugs (2.7 versus 2.3 hours), the terminal half-life for frovatriptan was longer than rizatriptan (29.3 versus 3.2 hours, P<0.0001). The proportion of patients who were pain-free at 4 hours without rescue medication was higher in the frovatriptan-treated group, (38.9 versus 5.6%, P=0.045). The cumulative hazard of recurrence over 72 h was reduced by frovatriptan compared to rizatriptan-treated patients (log-rank test, P=0.04). Pain-free and pain-relief episodes for the study period were positively correlated with the concentration:maximum concentration (Cmax) ratio for frovatriptan (r=0.52, P=0.028), but not rizatriptan. Recurrence rate was negatively correlated with the concentration:Cmax ratio for both frovatriptan (r=-0.96, P=0.0024) and rizatriptan (r=-0.98, P=0.0004). Fewer adverse events were observed for frovatriptan compared to rizatriptan (one versus eight, P=0.021). CONCLUSION: This pilot study indicates that a similar extent of initial pain relief is afforded by both triptans in migraine treatment. The longer duration of action of frovatriptan parallels and correlates with its PK profile.


Assuntos
Carbazóis/uso terapêutico , Transtornos de Enxaqueca/tratamento farmacológico , Agonistas do Receptor de Serotonina/uso terapêutico , Triazóis/uso terapêutico , Triptaminas/uso terapêutico , Adulto , Carbazóis/efeitos adversos , Estudos Cross-Over , Método Duplo-Cego , Feminino , Meia-Vida , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos de Enxaqueca/fisiopatologia , Projetos Piloto , Recidiva , Agonistas do Receptor de Serotonina/efeitos adversos , Agonistas do Receptor de Serotonina/farmacocinética , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento , Triazóis/efeitos adversos , Triazóis/farmacocinética , Triptaminas/efeitos adversos , Triptaminas/farmacocinética
16.
Antimicrob Agents Chemother ; 58(9): 5102-10, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24936593

RESUMO

Overexpression of the multidrug efflux pump MDR1 is one mechanism by which the pathogenic yeast Candida albicans develops resistance to the antifungal drug fluconazole. The constitutive upregulation of MDR1 in fluconazole-resistant, clinical C. albicans isolates is caused by gain-of-function mutations in the zinc cluster transcription factor Mrr1. It has been suggested that Mrr1 activates MDR1 transcription by recruiting Ada2, a subunit of the SAGA/ADA coactivator complex. However, MDR1 expression is also regulated by the bZIP transcription factor Cap1, which mediates the oxidative stress response in C. albicans. Here, we show that a hyperactive Mrr1 containing a gain-of-function mutation promotes MDR1 overexpression independently of Ada2. In contrast, a C-terminally truncated, hyperactive Cap1 caused MDR1 overexpression in a wild-type strain but only weakly in mutants lacking ADA2. In the presence of benomyl or H2O2, compounds that induce MDR1 expression in an Mrr1- and Cap1-dependent fashion, MDR1 was upregulated with the same efficiency in wild-type and ada2Δ cells. These results indicate that Cap1, but not Mrr1, recruits Ada2 to the MDR1 promoter to induce the expression of this multidrug efflux pump and that Ada2 is not required for MDR1 overexpression in fluconazole-resistant C. albicans strains containing gain-of-function mutations in Mrr1.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Candida albicans/genética , Proteínas de Ciclo Celular/genética , Farmacorresistência Fúngica Múltipla/genética , Proteínas Fúngicas/genética , Regulação para Cima/genética , Candida albicans/efeitos dos fármacos , Fluconazol/farmacologia , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Regulação Fúngica da Expressão Gênica/genética , Peróxido de Hidrogênio/farmacologia , Mutação/genética , Regiões Promotoras Genéticas/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/genética , Regulação para Cima/efeitos dos fármacos
17.
Cough ; 10(1): 7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25632296

RESUMO

BACKGROUND: Persistent dry cough is a well known unwanted effect of Angiotensin-Converting Enzyme inhibitors (ACE-i). Animal studies have shown that the ACE-i zofenopril has a less tussigenic effect compared to the widely used ACE-i ramipril. The aim of this study was to compare cough sensitivity to inhaled tussigens, as well as spontaneous cough in response to the administration of zofenopril and ramipril in healthy volunteers; pharmacokinetic (PK) data of both zofenopril and ramipril, as well as their respective active forms, zofenoprilat and ramiprilat, was also collected. METHODS: Forty healthy volunteers were enrolled in a randomized crossover study. Patients were administered zofenopril calcium salt (test drug) coated tablets, 30 mg daily dose or ramipril (reference drug) tablets, 10 mg daily dose, for 7 consecutive days in two periods separated by a 21-day wash-out period. Cough sensitivity to capsaicin and citric acid was assessed as the concentration of each tussigenic agent causing at least 2 (C2) or 5 coughs (C5); spontaneous cough was also monitored throughout the study. PK parameters of zofenopril, ramipril and their active forms, were collected for each of the two study periods. Airway inflammation, as assessed by fractional exhaled nitric oxide (FeNO) and bradykinin (BK) levels, were measured prior to and following each treatment period. RESULTS: Ramipril, but not zofenopril, increased (p < 0.01) cough sensitivity to both tussigenic agents as assessed by C2. With citric acid, C5 values calculated after both ramipril and zofenopril administration were significantly (p < 0.05 and p < 0.01, respectively) lower than corresponding control values. With both ACE-i drugs, spontaneous cough was infrequently reported by subjects. Zofenopril/zofenoprilat PK analysis showed higher area under the curve of plasma concentration, τ values (ng/ml x h) than ramipril/ramiprilat (zofenopril vs. ramipril, 84.25 ± 34.47 vs. 47.40 ± 21.30; and zofenoprilat vs. ramiprilat, 653.67 ± 174.91 vs. 182.26 ± 61.28). Both ACE-i drugs did not affect BK plasma levels; in contrast, ramipril, but not zofenopril, significantly increased control FeNO values (from 24 ± 9.6 parts per billion [PPB] to 33 ± 16 PPB; p < 0.01). CONCLUSIONS: Zofenopril has a more favourable profile when compared to ramipril as shown by a reduced pro-inflammatory activity and less impact on the cough reflex.

18.
Semin Thromb Hemost ; 39(7): 794-802, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24014070

RESUMO

Life expectancy for persons with hemophilia (PWH) has considerably increased in the last decades as a direct result of the availability of modern therapies to control the clotting defect. Because their life expectancy now matches that of the general population, PWH are experiencing age-related comorbidities, such as, cardiovascular diseases, metabolic syndrome, renal diseases, sexuality issues, malignancies, and neurologic problems, that until recently have been rarely seen in this group of patients. In this article, we present a summary of the current knowledge on the aging PWH along with the clinical approaches that may be integrated into the routine comprehensive care of these patients for preventing, diagnosing, and monitoring age-related comorbidities. In general, patients with and without hemophilia should receive similar care, with close collaboration between the physician treating PWH and the specialty expert treating the comorbid disease.


Assuntos
Hemofilia A/terapia , Fatores Etários , Comorbidade , Hemofilia A/tratamento farmacológico , Hemofilia A/prevenção & controle , Humanos , Expectativa de Vida
19.
PLoS One ; 6(9): e25623, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21980509

RESUMO

The pathogenic yeast Candida albicans can develop resistance to the widely used antifungal agent fluconazole, which inhibits ergosterol biosynthesis, by the overexpression of genes encoding multidrug efflux pumps or ergosterol biosynthesis enzymes. Zinc cluster transcription factors play a central role in the transcriptional regulation of drug resistance. Mrr1 regulates the expression of the major facilitator MDR1, Tac1 controls the expression of the ABC transporters CDR1 and CDR2, and Upc2 regulates ergosterol biosynthesis (ERG) genes. Gain-of-function mutations in these transcription factors result in constitutive overexpression of their target genes and are responsible for fluconazole resistance in many clinical C. albicans isolates. The transcription factor Ndt80 contributes to the drug-induced upregulation of CDR1 and ERG genes and also binds to the MDR1 and CDR2 promoters, suggesting that it is an important component of all major transcriptional mechanisms of fluconazole resistance. However, we found that Ndt80 is not required for the induction of MDR1 and CDR2 expression by inducing chemicals. CDR2 was even partially derepressed in ndt80Δ mutants, indicating that Ndt80 is a repressor of CDR2 expression. Hyperactive forms of Mrr1, Tac1, and Upc2 promoted overexpression of MDR1, CDR1/CDR2, and ERG11, respectively, with the same efficiency in the presence and absence of Ndt80. Mrr1- and Tac1-mediated fluconazole resistance was even slightly enhanced in ndt80Δ mutants compared to wild-type cells. These results demonstrate that Ndt80 is dispensable for the constitutive overexpression of Mrr1, Tac1, and Upc2 target genes and the increased fluconazole resistance of strains that have acquired activating mutations in these transcription factors.


Assuntos
Candida albicans/efeitos dos fármacos , Candida albicans/metabolismo , Proteínas de Ligação a DNA/metabolismo , Farmacorresistência Fúngica/efeitos dos fármacos , Fluconazol/farmacologia , Proteínas Fúngicas/metabolismo , Fatores de Transcrição/metabolismo , Alelos , Candida albicans/genética , Farmacorresistência Fúngica/genética , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
20.
Antimicrob Agents Chemother ; 55(5): 2061-6, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21343453

RESUMO

Overexpression of the multidrug efflux pump Mdr1 causes increased fluconazole resistance in the pathogenic yeast Candida albicans. The transcription factors Mrr1 and Cap1 mediate MDR1 upregulation in response to inducing stimuli, and gain-of-function mutations in Mrr1 or Cap1, which render the transcription factors hyperactive, result in constitutive MDR1 overexpression. The essential MADS box transcription factor Mcm1 also binds to the MDR1 promoter, but its role in inducible or constitutive MDR1 upregulation is unknown. Using a conditional mutant in which Mcm1 can be depleted from the cells, we investigated the importance of Mcm1 for MDR1 expression. We found that Mcm1 was dispensable for MDR1 upregulation by H2O2 but was required for full MDR1 induction by benomyl. A C-terminally truncated, hyperactive Cap1 could upregulate MDR1 expression both in the presence and in the absence of Mcm1. In contrast, a hyperactive Mrr1 containing a gain-of-function mutation depended on Mcm1 to cause MDR1 overexpression. These results demonstrate a differential requirement for the coregulator Mcm1 for Cap1- and Mrr1-mediated MDR1 upregulation. When activated by oxidative stress or a gain-of-function mutation, Cap1 can induce MDR1 expression independently of Mcm1, whereas Mrr1 requires either Mcm1 or an active Cap1 to cause overexpression of the MDR1 efflux pump. Our findings provide more detailed insight into the molecular mechanisms of drug resistance in this important human fungal pathogen.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Candida albicans/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas Fúngicas/metabolismo , Proteína 1 de Manutenção de Minicromossomo/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Fatores de Transcrição de Zíper de Leucina Básica , Western Blotting , Candida albicans/genética , Proteínas de Ciclo Celular/genética , Citometria de Fluxo , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica/genética , Regulação Fúngica da Expressão Gênica/fisiologia , Proteína 1 de Manutenção de Minicromossomo/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
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