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Hu L, Bai G, Xu Q, Zhao G, Jiang N, Yao H, Liu X, Du Z. Candidalysin amplifies the immune inflammatory response in Candida albicans keratitis through the TREM-1/DAP12 pathway. Int Immunopharmacol 2023; 119:110195. [PMID: 37087869 DOI: 10.1016/j.intimp.2023.110195] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 04/10/2023] [Accepted: 04/11/2023] [Indexed: 04/25/2023]
Abstract
Candidalysin is a fungal peptide toxin secreted by Candida albicans hyphae during invasion into epithelial cells. In Candida albicans-infected mucosa, candidalysin causes epithelial cell damage and activates downstream inflammatory responses, especially the release of inflammatory cytokines. However, the role of candidalysin in Candida albicans corneal keratitis remains unexplored. Moreover, it remains unclear whether candidalysin regulates the inflammatory response through the TREM-1/DAP12 pathway in Candida albicans corneal keratitis. In this study, we determined the expression pattern of TREM-1 in a mouse model of Candida albicans corneal keratitis and investigated the molecular mechanism underlying the inflammatory response regulation by candidalysin. The corneal keratitis model was established in C57BL/6 mice. In the GF9 group, mice were pretreated and then treated with the TREM-1 inhibitor GF9; in the candidalysin group, mice were treated with peptide candidalysin; and in the PD98059 group, mice were pretreated with the ERK inhibitor PD98059. Slit-lamp photography, clinical scoring, PCR, western blotting and immunofluorescence assay were performed to observe disease response and GF9 therapeutic efficacy. Pretreatment with candidalysin or PD98059 was performed before Candida albicans infection. GF9 treatment reduced the expression of TREM-1 and cytokines in the infected mouse cornea, whereas candidalysin treatment increased the expression of TREM-1, p-ERK, and cytokines, and this increase was inhibited by GF9. The candidalysin-induced increment of TREM-1, p-ERK, and cytokines was inhibited by PD98059 pretreatment. These data suggest that candidalysin can initiate inflammatory response in Candida albicans corneal keratitis through the TREM-1/DAP12 pathway and can regulate cytokine expression by enhancing ERK phosphorylation.
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Affiliation(s)
- Liting Hu
- Department of Ophthalmology, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China
| | - Guitao Bai
- Department of Ophthalmology, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China; Department of Ophthalmology, Zigong First People's Hospital, 42 Shang Yihao Branch Road, ZiGong 643000, China
| | - Qiang Xu
- Department of Ophthalmology, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China
| | - Guiqiu Zhao
- Department of Ophthalmology, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China
| | - Nan Jiang
- Department of Ophthalmology, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China
| | - Hua Yao
- Department of Ophthalmology, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China
| | - Xueqing Liu
- Department of Ophthalmology, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China
| | - Zhaodong Du
- Department of Ophthalmology, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China.
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Dhimmar B, Pokale R, Rahamathulla M, Hani U, Alshahrani MY, Alshehri S, Shakeel F, Alam P, Osmani RAM, Patil AB. Newfangled Topical Film-Forming Solution for Facilitated Antifungal Therapy: Design, Development, Characterization, and In Vitro Evaluation. Polymers (Basel) 2023; 15:1003. [PMID: 36850286 PMCID: PMC9961451 DOI: 10.3390/polym15041003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/11/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023] Open
Abstract
Luliconazole is a broad-spectrum topical antifungal agent that acts by altering the synthesis of fungi cell membranes. Literature suggests that the recurrence of fungal infection can be avoided by altering the pH of the site of infection. Studies have also suggested that fungi thrive by altering skin pH to be slightly acidic, i.e., pH 3-5. The current study is aimed to design, develop, characterize, and evaluate an alkaline pH-based antifungal spray solution for antifungal effects. Luliconazole was used as an antifungal agent and an alkaline spray was formulated for topical application by using Eudragit RS 100, propylene glycol (PG), water, sodium bicarbonate, and ethanol via solubilization method. Herein, sodium bicarbonate was used as an alkalizing agent. Based on DSC, FTIR, PXRD, scanning electron microscopy (SEM), and rheological analysis outcomes, the drug (luliconazole) and polymer were found to be compatible. F-14 formulation containing 22% Eudragit RS 100 (ERS), 1.5% PG, and 0.25% sodium bicarbonate was optimized by adopting the quality by design approach by using design of experiment software. The viscosity, pH, drying time, volume of solution post spraying, and spray angle were, 14.99 ± 0.21 cp, 8 pH, 60 s, 0.25 mL ± 0.05 mL, and 80 ± 2, respectively. In vitro drug diffusion studies and in vitro antifungal trials against Candida albicans revealed 98.0 ± 0.2% drug diffusion with a zone of inhibition of 9 ± 0.12 mm. The findings of the optimized luliconazole topical film-forming solution were satisfactory, it was compatible with human skin, and depicted sustained drug release that suggests promising applicability in facilitated topical antifungal treatments.
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Affiliation(s)
- Bhakti Dhimmar
- Department of Pharmaceutics, JSS College of Pharmacy, JSS Academy of Higher Education and Research (JSS AHER), Mysuru 570 015, Karnataka, India
| | - Rahul Pokale
- Department of Pharmaceutics, JSS College of Pharmacy, JSS Academy of Higher Education and Research (JSS AHER), Mysuru 570 015, Karnataka, India
| | - Mohamed Rahamathulla
- Department of Pharmaceutics, College of Pharmacy, King Khalid University, Abha 61421, Saudi Arabia
| | - Umme Hani
- Department of Pharmaceutics, College of Pharmacy, King Khalid University, Abha 61421, Saudi Arabia
| | - Mohammad Y. Alshahrani
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Khalid University, Guraiger, Abha 61421, Saudi Arabia
| | - Sultan Alshehri
- Department of Pharmaceutical Sciences, College of Pharmacy, AlMaarefa University, Ad Diriyah 13713, Saudi Arabia
| | - Faiyaz Shakeel
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
| | - Prawez Alam
- Department of Pharmacognosy, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia
| | - Riyaz Ali M. Osmani
- Department of Pharmaceutics, JSS College of Pharmacy, JSS Academy of Higher Education and Research (JSS AHER), Mysuru 570 015, Karnataka, India
| | - Amit B. Patil
- Department of Pharmaceutics, JSS College of Pharmacy, JSS Academy of Higher Education and Research (JSS AHER), Mysuru 570 015, Karnataka, India
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Das S, Goswami AM, Saha T. An insight into the role of protein kinases as virulent factors, regulating pathogenic attributes in Candida albicans. Microb Pathog 2022; 164:105418. [DOI: 10.1016/j.micpath.2022.105418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 01/21/2022] [Accepted: 01/21/2022] [Indexed: 11/26/2022]
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Dai C, Me R, Gao N, Su G, Wu X, Yu FSX. Role of IL-36γ/IL-36R Signaling in Corneal Innate Defense Against Candida albicans Keratitis. Invest Ophthalmol Vis Sci 2021; 62:10. [PMID: 33970198 PMCID: PMC8114008 DOI: 10.1167/iovs.62.6.10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 04/12/2021] [Indexed: 12/17/2022] Open
Abstract
PURPOSE Interleukin (IL)-36 cytokines have been shown to play either beneficial or detrimental roles in the infection of mucosal tissues in a pathogen-dependent manner, but their involvement in fungal keratitis remains elusive. We herein investigated their expression and function in mediating corneal innate immunity against Candida albicans infection. METHODS Gene expression in mouse corneas with or without C. albicans infection was determined by regular RT- and real-time (q)-PCR, Western blot analysis, ELISA or proteome profile assay. The severity of C. albicans keratitis was assessed using clinical scoring, bacterial counting, and myeloperoxidase (MPO) activity as an indicator of neutrophil infiltration. IL36R knockout mice and IL-33-specific siRNA were used to assess the involvement IL-33 signaling in C. albicans-infected corneas. B6 CD11c-DTR mice and clodronate liposomes were used to define the involvement of dendritic cells (DCs) and macrophages in IL-36R signaling and C. albicans keratitis, respectively. RESULTS IL-36γ were up-regulated in C57BL6 mouse corneas in response to C. albicans infection. IL-36 receptor-deficient mice display increased severity of keratitis, with a higher fungal load, MPO, and IL-1β levels, and lower soluble sIL-1Ra and calprotectin levels. Exogenous IL-36γ prevented fungal keratitis pathogenesis with lower fungal load and MPO activity, higher expression of sIL-1Ra and calprotectin, and lower expression of IL-1β, at mRNA or protein levels. Protein array analysis revealed that the expression of IL-33 and REG3G were related to IL-36/IL36R signaling, and siRNA downregulation of IL-33 increased the severity of C. albicans keratitis. Depletion of dendritic cells or macrophages resulted in severe C. albicans keratitis and yet exhibited minimal effects on exogenous IL-36γ-induced protection against C. albicans infection in B6 mouse corneas. CONCLUSIONS IL-36/IL36R signaling plays a protective role in fungal keratitis by promoting AMP expression and by suppressing fungal infection-induced expression of proinflammatory cytokines in a dendritic cell- and macrophage-independent manner.
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Affiliation(s)
- Chenyang Dai
- Departments of Ophthalmology and Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong Province, China
| | - Rao Me
- Departments of Ophthalmology and Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Nan Gao
- Departments of Ophthalmology and Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Guanyu Su
- Departments of Ophthalmology and Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Xinyi Wu
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong Province, China
| | - Fu-Shin X. Yu
- Departments of Ophthalmology and Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
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El-Kholy MA, Helaly GF, El Ghazzawi EF, El-Sawaf G, Shawky SM. Virulence Factors and Antifungal Susceptibility Profile of C. tropicalis Isolated from Various Clinical Specimens in Alexandria, Egypt. J Fungi (Basel) 2021; 7:jof7050351. [PMID: 33947158 PMCID: PMC8146935 DOI: 10.3390/jof7050351] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 04/21/2021] [Accepted: 04/26/2021] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND The incidence of candidiasis caused by non-albicans Candida (NAC) species is increasing. Candida tropicalis has emerged as one of the most important NAC species. This study aims to examine the antifungal susceptibility profile and some virulence factors of C. tropicalis isolated from various clinical specimens. METHODS A total of 71 C. tropicalis isolates from various clinical specimens (69.01%, 18.31%, 9.86%, and 2.82% of isolates were collected from urine, respiratory samples, blood, and skin and soft tissue infections, respectively) from ICU patients in Alexandria, Egypt. The isolates were identified at species level by CHROMagar Candida and VITEK 2 compact system. Furthermore, the antifungal susceptibility was determined using the VITEK 2 system AST-YS07 card containing different antifungals. Hemolysin, phospholipase, and proteinase activity and biofilm formation were also tested as virulence factors. RESULTS Only 30 isolates (42.25%) were non-susceptible (MIC ≥ 4 µg/mL) to fluconazole, of which 28 isolates showed non-susceptibility (MIC ≥ 0.25 µg/mL) to voriconazole. All isolates showed both hemolysin and proteinase activities, while only 9 isolates (12.68%) showed phospholipase production and 70 isolates (98.59%) demonstrated biofilm formation. Strong biofilm production was observed among the blood culture isolates (85.71%), followed by the respiratory and urinary isolates (61.54% and 46.94%, respectively). CONCLUSIONS This study sought to provide useful data on the antifungal susceptibility of C. tropicalis isolates from ICU patients suffering from invasive infections with an increased trend towards elevated MICs levels of both fluconazole and voriconazole. Due to the high incidence of systemic candidiasis and antifungal resistance, C. tropicalis is emerging as a serious root of infections. Therefore, early and accurate identification of Candida species along with susceptibility testing is of utmost importance.
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Affiliation(s)
- Mohammed A. El-Kholy
- Department of Microbiology and Biotechnology, Clinical and Biological Sciences Division, College of Pharmacy, Arab Academy for Science, Technology and Maritime Transport (AASTMT), P.O. Box 1029, Alexandria, Egypt
- Correspondence:
| | - Ghada F. Helaly
- Department of Microbiology, Medical Research Institute, Alexandria University, P.O. Box 1029, Alexandria, Egypt; (G.F.H.); (E.F.E.G.); (G.E.-S.); (S.M.S.)
| | - Ebtisam F. El Ghazzawi
- Department of Microbiology, Medical Research Institute, Alexandria University, P.O. Box 1029, Alexandria, Egypt; (G.F.H.); (E.F.E.G.); (G.E.-S.); (S.M.S.)
| | - Gamal El-Sawaf
- Department of Microbiology, Medical Research Institute, Alexandria University, P.O. Box 1029, Alexandria, Egypt; (G.F.H.); (E.F.E.G.); (G.E.-S.); (S.M.S.)
| | - Sherine M. Shawky
- Department of Microbiology, Medical Research Institute, Alexandria University, P.O. Box 1029, Alexandria, Egypt; (G.F.H.); (E.F.E.G.); (G.E.-S.); (S.M.S.)
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Trovato L, Marino A, Pizzo G, Oliveri S. Case Report: Molecular Diagnosis of Fungal Keratitis Associated With Contact Lenses Caused by Fusarium solani. Front Med (Lausanne) 2021; 8:579516. [PMID: 33842493 PMCID: PMC8024464 DOI: 10.3389/fmed.2021.579516] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 02/17/2021] [Indexed: 11/13/2022] Open
Abstract
Fusarium is a filamentous fungus commonly found in the environment and is the major cause of fungal keratitis. We report a case of keratomycosis caused by Fusarium solani in a patient using disposable soft contact lenses. A delay in diagnosis led to the initiation of an empirical antifungal treatment with the subsequent deterioration of the patient's clinical condition. The use of the real-time quantitative PCR assay confirmed keratitis from F. solani providing a result in <48 h and therefore giving the possibility of quickly starting targeted antifungal therapy. The patient had an improvement in eye condition after the diagnosis of keratitis by F. solani and the rapid change to targeted antifungal treatment. For the rapid identification of corneal fungal pathogens, we believe that PCR may be added for the diagnosis of mycotic keratitis pending the isolation in culture that is necessary for in vitro susceptibility testing.
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Affiliation(s)
- Laura Trovato
- Laboratory Analysis Unit, Azienda Ospedaliero Universitaria Policlinico "G. Rodolico-San Marco", Catania, Italy.,Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Antonio Marino
- Ophthalmology Unit, Azienda di Rilievo Nazionale e di Alta Specializzazione Garibaldi, Catania, Italy
| | - Giovanni Pizzo
- Ophthalmology Unit, Azienda di Rilievo Nazionale e di Alta Specializzazione Garibaldi, Catania, Italy
| | - Salvatore Oliveri
- Laboratory Analysis Unit, Azienda Ospedaliero Universitaria Policlinico "G. Rodolico-San Marco", Catania, Italy.,Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
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7
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Zhu BB, Zhou J, Zheng J, Zhang Y, Wan T, Huang XD, Lin L, Jin XM. Corneal graft melting: a systematic review. Int J Ophthalmol 2020; 13:493-502. [PMID: 32309189 DOI: 10.18240/ijo.2020.03.19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 12/20/2019] [Indexed: 12/22/2022] Open
Abstract
Corneal graft melting is a severe complication of keratoplasty. This review is to summarize the incidence, the pathogenesis, the risk factors, the prognosis and the prevention of corneal graft melting after keratoplasty. We systematically searched PubMed, Web of Science and WanFang database to retrieve potentially eligible articles about relevant clinical reports and animal experiments. We read the full texts to identify eligible articles. The selection of studies and data extraction were performed independently by two reviewers. In conclusion, the pathogenesis of corneal graft melting is complicated, and many risk factors are closely related to corneal graft melting. Analysis of pathogenesis and risk factors of corneal graft melting can facilitate the development of targeted therapies to better guide clinical practice.
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Affiliation(s)
- Bin-Bin Zhu
- Eye Center, the Affiliated Second Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, Zhejiang Province, China
| | - Jie Zhou
- Eye Center, the Affiliated Second Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, Zhejiang Province, China
| | - Jiao Zheng
- Eye Center, the Affiliated Second Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, Zhejiang Province, China
| | - Yue Zhang
- Eye Center, the Affiliated Second Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, Zhejiang Province, China
| | - Ting Wan
- Eye Center, the Affiliated Second Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, Zhejiang Province, China
| | - Xiao-Dan Huang
- Eye Center, the Affiliated Second Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, Zhejiang Province, China
| | - Lin Lin
- Eye Center, the Affiliated Second Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, Zhejiang Province, China
| | - Xiu-Ming Jin
- Eye Center, the Affiliated Second Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, Zhejiang Province, China
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Mahmoudi S, Masoomi A, Ahmadikia K, Tabatabaei SA, Soleimani M, Rezaie S, Ghahvechian H, Banafsheafshan A. Fungal keratitis: An overview of clinical and laboratory aspects. Mycoses 2018; 61:916-930. [PMID: 29992633 DOI: 10.1111/myc.12822] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 06/28/2018] [Indexed: 12/22/2022]
Abstract
Mycotic keratitis or keratomycosis is a fungal infection with global distribution. The dominant aetiology of this disease varies based on geographical origin, socioeconomic status, and climatic condition. Generally, Aspergillus spp. and Fusarium spp. are common in tropical and subtropical regions and Candida spp. are dominant in temperate areas. Demonstration of fungal elements in microscopic examination besides the isolation of fungi in culture is the gold standard of laboratory diagnosis. As the culture is a time-consuming procedure, other approaches such as in vivo confocal microscopy which produces real-time imaging of corneal tissue and molecular techniques have been developed to facilitate rapid diagnosis of fungal keratitis. The first choice of treatment is topical natamycin, although topical amphotericin B is the best choice for Aspergillus and Candida keratitis. Regarding the diversity of fungal aetiology and the emergence of drug resistance in some genera and species, proper identification using molecular methods and antifungal susceptibility testing could provide useful data. Furthermore, as the better efficacy of combination therapy in comparison to monotherapy is reported, in vitro determination of interactions between various drugs seem informative. This review aims to provide a general and updated view on the aetiology, risk factors, epidemiology, clinical and laboratory diagnosis, and management of fungal keratitis.
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Affiliation(s)
- Shahram Mahmoudi
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.,Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmad Masoomi
- Department of Ocular Trauma and Emergency, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Kazem Ahmadikia
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Seyed Ali Tabatabaei
- Department of Ocular Trauma and Emergency, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Soleimani
- Department of Ocular Trauma and Emergency, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Sassan Rezaie
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein Ghahvechian
- Department of Ocular Trauma and Emergency, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Ali Banafsheafshan
- Department of Ocular Trauma and Emergency, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
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Turecka K, Chylewska A, Kawiak A, Waleron KF. Antifungal Activity and Mechanism of Action of the Co(III) Coordination Complexes With Diamine Chelate Ligands Against Reference and Clinical Strains of Candida spp. Front Microbiol 2018; 9:1594. [PMID: 30072969 PMCID: PMC6058090 DOI: 10.3389/fmicb.2018.01594] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 06/26/2018] [Indexed: 12/16/2022] Open
Abstract
Although many antifungal agents are available in clinical treatment, increasing resistance of fungi, especially Candida species, to the available drugs requires the development of new safe and non-toxic compounds with novel modes of action as effective treatment against resistant microorganisms. Cobalt complexes are very interesting and attractive as potential candidates with antimicrobial activity. Their therapeutic uses as antiviral, antibacterial antifungal, antiparasitic, antitumour, transferrin transporters, and anti-inflammatory agents are being intensively investigated. In this study we examined the antifungal activity of Co(III) complexes with diamine chelate ligands against a broad spectrum of Candida species. Minimum inhibitory concentration was determined by the microbroth dilution method and with serial passaging assay; the synergistic antimicrobial activity of the tested complexes combined with two antifungal drugs (ketoconazole and amphotericin B) was made by checkerboard assay. The effects of Co(III) complexes on yeast cell morphology were studied by optical and transmission electron microscopy. The mode of action of Co(III) complexes on the yeast cell wall (sorbitol assay) and cell membrane (ergosterol assay) were investigated. The cytotoxic effects of the tested compounds on red blood cells and the human keratinocyte (HaCaT) cell line were also evaluated. The analyzed compounds revealed significant antifungal activity for selected strains of Candida species; [CoCl2(dap)2]Cl (1) and [CoCl2(en)2]Cl (2) were more effective than ketoconazole. Its probable mechanism of action did not involve the cell wall or ergosterol binding. However, the checkerboard assay showed, that the antifungal activity of ketoconazole increased in combination with the tested complexes of Co(III). Our results suggest that both diamine complexes with Co(III) analogs caused damage to mitochondrial membrane or the membrane of the endoplasmic reticulum. The effect was observed by transmission electron microscope. Co(III) complexes with diamine chelate ligands are non-toxic at concentrations active against Candida species. This study provides new data on potential antifungal drugs, especially against Candida species.
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Affiliation(s)
- Katarzyna Turecka
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Medical University of Gdańsk, Gdańsk, Poland
| | - Agnieszka Chylewska
- Department of Bioinorganic Chemistry, Faculty of Chemistry, University of Gdańsk, Gdańsk, Poland
| | - Anna Kawiak
- Department of Biotechnology, Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Gdańsk, Poland
| | - Krzysztof F Waleron
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Medical University of Gdańsk, Gdańsk, Poland
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10
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Verma S, Shakya VPS, Idnurm A. Exploring and exploiting the connection between mitochondria and the virulence of human pathogenic fungi. Virulence 2018; 9:426-446. [PMID: 29261004 PMCID: PMC5955198 DOI: 10.1080/21505594.2017.1414133] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 12/04/2017] [Accepted: 12/04/2017] [Indexed: 12/17/2022] Open
Abstract
Mitochondria are best known for their role in the production of ATP; however, recent research implicates other mitochondrial functions in the virulence of human pathogenic fungi. Inhibitors of mitochondrial succinate dehydrogenase or the electron transport chain are successfully used to combat plant pathogenic fungi, but similar inhibition of mitochondrial functions has not been pursued for applications in medical mycology. Advances in understanding mitochondrial function relevant to human pathogenic fungi are in four major directions: 1) the role of mitochondrial morphology in virulence, 2) mitochondrial genetics, with a focus on mitochondrial DNA recombination and mitochondrial inheritance 3) the role of mitochondria in drug resistance, and 4) the interaction of mitochondria with other organelles. Collectively, despite the similarities in mitochondrial functions between fungi and animals, this organelle is currently an under-explored potential target to treat medical mycoses. Future research could define and then exploit those mitochondrial components best suited as drug targets.
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Affiliation(s)
- Surbhi Verma
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Viplendra P. S. Shakya
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Alexander Idnurm
- School of BioSciences, University of Melbourne, Parkville, VIC, Australia
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11
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Wang H, Yao C, Qian K, Guo Q, Shu W, Chen P, Song W, Wang Y. Balance of disinfection and cytotoxicity of hydroxypropyltrimethyl ammonium chloride chitosan with polyhexamethylene biguanide at low concentrations. JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY 2017. [DOI: 10.1080/10601325.2017.1381922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Huafu Wang
- Chemistry and Chemical Engineering Department, School of Chemistry and Chemical Engineering, Southeast University, Nanjing, P.R. China
| | - Chen Yao
- Chemistry and Chemical Engineering Department, School of Chemistry and Chemical Engineering, Southeast University, Nanjing, P.R. China
| | - Kun Qian
- Chemistry and Chemical Engineering Department, School of Chemistry and Chemical Engineering, Southeast University, Nanjing, P.R. China
| | - Qing Guo
- Chemistry and Chemical Engineering Department, School of Chemistry and Chemical Engineering, Southeast University, Nanjing, P.R. China
| | - Weixia Shu
- Research and Development Department, Hydron contact lens co., LTD, Danyang, P.R. China
| | - Ping Chen
- Research and Development Department, Hydron contact lens co., LTD, Danyang, P.R. China
| | - Wei Song
- Chemistry and Chemical Engineering Department, School of Chemistry and Chemical Engineering, Southeast University, Nanjing, P.R. China
| | - Yihong Wang
- Chemistry and Chemical Engineering Department, School of Chemistry and Chemical Engineering, Southeast University, Nanjing, P.R. China
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12
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Hua X, Chi W, Su L, Li J, Zhang Z, Yuan X. ROS-induced Oxidative Injury involved in Pathogenesis of Fungal Keratitis via p38 MAPK Activation. Sci Rep 2017; 7:10421. [PMID: 28874754 PMCID: PMC5585305 DOI: 10.1038/s41598-017-09636-w] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 07/25/2017] [Indexed: 12/17/2022] Open
Abstract
This study was to explore the mechanism by which reactive oxygen species (ROS)-induced oxidative stress involved in the pathogenesis of fungal keratitis using an in vivo experimental keratitis mouse model and an in vitro culture model of human corneal epithelial cells (HCECs). Compared to normal control mice and HCECs, ROS production was markedly increased in fungal corneas and HCECs exposed to Candida albicans, accompanied by p38 mitogen-activated protein kinases (MAPK) activation. Increased products of oxidative markers, malondialdehyde (MDA), 4–hydroxynonenal (HNE), mitochondria DNA 8-OHdG and aconitase-2 were observed in fungal infected corneas and HCECs. Fungal infection also increased the mRNA expression and protein production of heme oxygenase-1 (HMOX1) and cyclooxygenase-2 (COX2), with suppressed levels of antioxidant enzymes, superoxide dismutase-1 (SOD1), glutathione peroxidase-1 (GPx1) and peroxiredoxin-4 (PRDX4). Interestingly, the levels of ROS, oxidative markers and oxygenases were significantly reduced by co-cultured p38 inhibitor SB203580. Furthermore, SB203580 restored the levels of antioxidant enzymes suppressed by fungus. Our findings demonstrated for the first time that ROS-induced oxidative injury is involved in pathogenesis of fungal keratitis via p38 MAPK pathway, suggesting the novel therapeutic targets for the potential treatment of fungal keratitis.
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Affiliation(s)
- Xia Hua
- Department of Ophthalmology, Tianjin Orbit Research Institute, the Second Hospital of Tianjin Medical University, Tianjin, China
| | - Wei Chi
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
| | - Long Su
- Department of Ophthalmology, Tianjin Orbit Research Institute, the Second Hospital of Tianjin Medical University, Tianjin, China
| | - Jin Li
- Zhejiang Eye Hospital, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China
| | - Zongduan Zhang
- Zhejiang Eye Hospital, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China
| | - Xiaoyong Yuan
- Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.
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Dong C, Gao N, Ross BX, Yu FSX. ISG15 in Host Defense Against Candida albicans Infection in a Mouse Model of Fungal Keratitis. Invest Ophthalmol Vis Sci 2017; 58:2948-2958. [PMID: 28599020 PMCID: PMC5469425 DOI: 10.1167/iovs.17-21476] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Purpose ISG15, a di-ubiquitin-like protein, is critical for controlling certain viral and bacterial infections. We sought to determine if ISG15 plays a role in corneal innate immunity against Candida albicans (C. albicans) using a C57BL/6 (B6) mouse model of human fungal keratitis. Methods Scarified corneas of adult B6 mice were pretreated with TLR5 ligand flagellin and then inoculated with C. albicans. The expression of ISG15 and other genes involved in ISG15 conjugation (ISGylation) was determined by real-time PCR. ISG15 expression and distribution in infected corneas were assessed by immunohistochemistry. ISGylation was examined by Western blotting. siRNA knockdown and recombinant ISG15 were used to elucidate the effects of ISG15 on controlling fungal keratitis by clinical scoring, fungal number plate counting, ELISA cytokine determination, and polymorphonuclear leukocytes (PMN) infiltration measurement. Results Heat-killed C. albicans induced expression of ISG15, and hBD2 was markedly enhanced by flagellin-pretreatment in cultured human primary corneal epithelial cells (CECs). In vivo, C. albicans infection induced the expression of ISG15, ISGylation-associated genes (UBE1L, UBCH8, and HERC5), and ISGylation in mouse CECs, all of which were enhanced by flagellin-pretreatment. siRNA knockdown of ISG15 increased keratitis severity, dampened flagellin-induced protection, and greatly suppressed the expressions of ISGylation enzymes, IFN-γ, but not CXCL2 in B6 mouse CECs. Recombinant ISG15, on the other hand, enhanced corneal innate immunity against C. albicans and suppressed infection-induced IL-1β, but not IL-Ra expression. ISG15 alone induced the expression of IL-1Ra, CXCL10, and CRAMP in mouse CECs. ISG15 was upregulated and secreted in cultured human CECs in response to challenge in a type 1 IFN-dependent manner. Conclusions Our data, for the first time, demonstrate that ISG15 acts as an immunomodulator in the cornea and plays a critical role in controlling fungal keratitis.
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Affiliation(s)
- Chen Dong
- Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States 2College of Biological Engineering, Henan University of Technology, Zhengzhou, Henan, China
| | - Nan Gao
- Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Bing X Ross
- Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Fu-Shin X Yu
- Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
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Maheronnaghsh M, Tolouei S, Dehghan P, Chadeganipour M, Yazdi M. Identification of Candida species in patients with oral lesion undergoing chemotherapy along with minimum inhibitory concentration to fluconazole. Adv Biomed Res 2016; 5:132. [PMID: 27656601 PMCID: PMC5025917 DOI: 10.4103/2277-9175.187394] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 06/15/2015] [Indexed: 02/02/2023] Open
Abstract
Background: Various species of Candida, especially Candida albicans was known as the most important etiological agent of fungal infections. Oral candidiasis is the most common fungal infection in patients undergoing chemotherapy. The purpose of this study was to identify Candida species from oral lesions of these patients and antifungal susceptibility of the clinical isolates. Materials and Methods: Among 385 patients with cancer, 55 (14.3%) showed oral lesions. Oral swabs were performed to identify the yeasts using direct smear and CHROMagar medium. Micro dilution method was prepared in different concentrations of fluconazole and minimum inhibitory concentration and minimum fungicidal concentration of each species were compared. Results: Oral candidiasis confirmed in 36 cases by direct examination and culture. C. albicans and non-albicans represented in 26 (72.2%) and 10 (27.8%) of the isolates, respectively. 76.5% of C. albicans and 23.5% non-albicans isolates were resistant to fluconazole. Data were shown that 62% and 30.7% of resistant strains of C. albicans were found in patient with gastrointestinal cancer and lymphoma respectively. Conclusion: Data were shown that C. albicans is the most commonly identified species in oral candidiasis and majority of fluconazole resistant C. albicans were found in patients with gastrointestinal cancer and lymphoma. Therefore, we recommend an alternative drug instead of fluconazole as a first line of treatment for these type of cancers and administration of fluconazole in patients undergoing chemotherapy should be prescribed in accordance with the type of cancer.
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Affiliation(s)
- Mehrnoush Maheronnaghsh
- Department of Parasitology and Mycology, School of Medicine, Faculty of Health, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Sepideh Tolouei
- Department of Parasitology and Mycology, School of Medicine, Faculty of Health, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Parvin Dehghan
- Department of Parasitology and Mycology, School of Medicine, Faculty of Health, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mostafa Chadeganipour
- Department of Parasitology and Mycology, School of Medicine, Faculty of Health, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Maryam Yazdi
- Department of Biostatistics and Epidemiology, Faculty of Health, Isfahan University of Medical Sciences, Isfahan, Iran
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Chitinase 3-Like 1 Promotes Candida albicans Killing and Preserves Corneal Structure and Function by Controlling Host Antifungal Responses. Infect Immun 2015; 83:4154-64. [PMID: 26238714 DOI: 10.1128/iai.00980-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 07/30/2015] [Indexed: 12/17/2022] Open
Abstract
Chitinase 3-like 1 (CHI3L1) has been shown to play a role in promoting antibacterial responses, decreasing tissue injury, and enhancing pulmonary repair. This study sought to elucidate the role of CHI3L1 in augmenting the corneal innate immune response to Candida albicans infection in an animal model of fungal keratitis. Flagellin applied topically 24 h prior to C. albicans inoculation significantly protected the corneal from C. albicans and induced CHI3L1 expression in C57BL/6 mouse corneas. CHI3L1, however, played a detectable but minor role in flagellin-induced protection. While C. albicans keratitis was more severe in the corneas treated with Chi3l1 small interfering RNA (siRNA), corneas treated with recombinant CHI3L1 before C. albicans inoculation had markedly ameliorated keratitis, reduced fungal load, and decreased polymorphonucleocyte (PMN) infiltration in an interleukin 13 receptor α2 (IL-13Rα2)-dependent manner. CHI3L1 treatment resulted in the induction of the antimicrobial peptides β-defensin 3, CRAMP, and chemokine CXCL10 and its receptor CXCR3 in corneal epithelial cells. Importantly, CHI3L1 administered after C. albicans inoculation also had strong protection against fungal keratitis, suggesting a therapeutic window. This is the first report demonstrating that CHI3L1 is induced during fungal infection, where it acts as an immunomodulator to promote fungal clearance and to regulate antifungal innate immune responses in the cornea.
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Ledbetter EC, Norman ML, Starr JK. In vivoconfocal microscopy for the detection of canine fungal keratitis and monitoring of therapeutic response. Vet Ophthalmol 2015; 19:220-9. [DOI: 10.1111/vop.12287] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Eric C. Ledbetter
- College of Veterinary Medicine; Department of Clinical Sciences; Cornell University; Ithaca NY 14853 USA
| | - Mary L. Norman
- College of Veterinary Medicine; Department of Clinical Sciences; Cornell University; Ithaca NY 14853 USA
| | - Jennifer K. Starr
- College of Veterinary Medicine; Department of Population Medicine and Diagnostic Sciences; Cornell University; Ithaca NY 14853 USA
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Liu X, Gao N, Dong C, Zhou L, Mi QS, Standiford TJ, Yu FSX. Flagellin-induced expression of CXCL10 mediates direct fungal killing and recruitment of NK cells to the cornea in response to Candida albicans infection. Eur J Immunol 2014; 44:2667-79. [PMID: 24965580 PMCID: PMC4165733 DOI: 10.1002/eji.201444490] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 04/29/2014] [Accepted: 06/20/2014] [Indexed: 11/10/2022]
Abstract
We previously showed that topical flagellin induces profound mucosal innate protection in the cornea against microbial infection, a response involving multiple genes and cell types. In this study, we used a Candida albicans (CA)-C57BL/6 mouse keratitis model to delineate the contribution of CXCL10- and CXCR3-expressing cells in flagellin-induced protection. Flagellin pretreatment markedly enhanced CXCL10 expression at 6 h post CA infection (hpi), but significantly dampened CXCL10 expression at 24 hpi. At the cellular level, CXCL10 was expressed in the epithelia at 6 hpi in flagellin-pretreated corneas, and concentrated at lesion sites 24 hpi. CXCR3-expressing cells were detected in great numbers at 24 hpi, organized within clusters at the lesion sites in CA-infected corneas. CXCL10 or CXCR3 neutralization increased keratitis severity and dampened flagellin-induced protection. CXCR3-positive cells were identified as NK cells, the depletion of which resulted in severe CA keratitis. Contributions from NK T-cells were excluded by finding no change in flagellin-induced protection in Rag1 KO mice. Recombinant CXCL10 inhibited CA growth in vitro and accelerated fungal clearance and inflammation resolution in vivo. Taken together, our data indicate that epithelium-expressed CXCL10 plays a critical role in fungal clearance and that CXCR3-expressing NK cells contribute to CA eradication in mouse corneas.
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Affiliation(s)
- Xiaowei Liu
- Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Nan Gao
- Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Chen Dong
- Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Li Zhou
- Henry Ford Immunology Program, Department of Dermatology, Department of Internal Medicine, Henry Ford Health System, Detroit, MI, USA
| | - Qing-Sheng Mi
- Henry Ford Immunology Program, Department of Dermatology, Department of Internal Medicine, Henry Ford Health System, Detroit, MI, USA
| | - Theodore J. Standiford
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, MI, USA
| | - Fu-Shin X. Yu
- Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA
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18
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Hua X, Yuan X, Tang X, Li Z, Pflugfelder SC, Li DQ. Human corneal epithelial cells produce antimicrobial peptides LL-37 and β-defensins in response to heat-killed Candida albicans. Ophthalmic Res 2014; 51:179-86. [PMID: 24662332 DOI: 10.1159/000357977] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 12/13/2013] [Indexed: 12/20/2022]
Abstract
AIMS To explore the innate response of human corneal epithelial cells (HCECs) exposed to fungus by producing antimicrobial peptides LL-37 and β-defensins. METHODS Primary HCECs were treated with heat-killed Candida albicans (HKCA) at different doses (10(3)-10(6) cells/ml) for 2-48 h. The cells were subjected to total RNA extraction, reverse transcription and quantitative real-time PCR for mRNA expression. Cells treated for 48 h were used for immunofluorescent staining and ELISA. RESULTS Human LL-37 and β-defensins (hBDs) 1-4 were detected in normal HCECs. The mRNA expression of LL-37, hBD2, and hBD3 was dose-dependently induced by HKCA with their peak levels at 4 h. HKCA (10(6) cells/ml) stimulated the mRNA of LL-37, hBD2, and hBD3 4.33 ± 1.81, 3.75 ± 1.31, and 4.91 ± 1.09 fold, respectively, in HCECs. The stimulated production of LL-37, hBD2, and hBD3 by HKCA was confirmed at protein levels by immunofluorescent staining and ELISA. The protein production of LL-37, hBD2, and hBD3 significantly increased to 109.1 ± 18.2 pg/ml, 4.33 ± 1.67 ng/ml, and 296.9 ± 81.8 pg/ml, respectively, in culture medium of HCECs exposed to HKCA (10(6) cells/ml) compared to untreated HCECs. CONCLUSIONS HCECs produce antimicrobial peptides, LL-37, hBD2 and hBD3, in response to stimulation of HKCA, which suggests a novel innate immune mechanism of the ocular surface in defense against fungal invasion.
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Affiliation(s)
- Xia Hua
- Tianjin Eye Hospital, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
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Spampinato C, Leonardi D. Candida infections, causes, targets, and resistance mechanisms: traditional and alternative antifungal agents. BIOMED RESEARCH INTERNATIONAL 2013; 2013:204237. [PMID: 23878798 PMCID: PMC3708393 DOI: 10.1155/2013/204237] [Citation(s) in RCA: 219] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 06/06/2013] [Accepted: 06/06/2013] [Indexed: 11/25/2022]
Abstract
The genus Candida includes about 200 different species, but only a few species are human opportunistic pathogens and cause infections when the host becomes debilitated or immunocompromised. Candida infections can be superficial or invasive. Superficial infections often affect the skin or mucous membranes and can be treated successfully with topical antifungal drugs. However, invasive fungal infections are often life-threatening, probably due to inefficient diagnostic methods and inappropriate initial antifungal therapies. Here, we briefly review our current knowledge of pathogenic species of the genus Candida and yeast infection causes and then focus on current antifungal drugs and resistance mechanisms. An overview of new therapeutic alternatives for the treatment of Candida infections is also provided.
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Affiliation(s)
- Claudia Spampinato
- Departamento de Química Biológica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Suipacha 531, 2000 Rosario, Argentina
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI, UNR-CONICET), Suipacha 531, 2000 Rosario, Argentina
| | - Darío Leonardi
- Departamento de Tecnología Farmacéutica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Suipacha 531, 2000 Rosario, Argentina
- Instituto de Química Rosario (IQUIR, UNR-CONICET), Suipacha 531, 2000 Rosario, Argentina
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Chung D, Haas H, Cramer RA. Coordination of hypoxia adaptation and iron homeostasis in human pathogenic fungi. Front Microbiol 2012; 3:381. [PMID: 23133438 PMCID: PMC3490150 DOI: 10.3389/fmicb.2012.00381] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 10/11/2012] [Indexed: 12/11/2022] Open
Abstract
In mammals, hypoxia causes facilitated erythropoiesis that requires increased iron availability with established links between oxygen and iron in regulation of the transcription factor hypoxia-inducible factor. Therefore, cellular responses to hypoxia and iron starvation are linked in mammals and are host conditions that pathogens encounter during infection. In human pathogenic fungi, molecular mechanisms underlying hypoxia adaptation and iron homeostasis have been investigated. However, the interconnected regulation of hypoxia adaptation and iron homeostasis remains to be fully elucidated. This review discusses the potential transcriptional regulatory links between hypoxia adaptation and iron homeostasis in human pathogenic fungi. Transcriptome analyses demonstrate that core regulators of hypoxia adaptation and iron homeostasis are involved in regulation of several common genes responsible for iron acquisition and ergosterol biosynthesis. Importantly, iron starvation increases susceptibility of fungal cells to antifungal drugs and decreased levels of ergosterol, while key hypoxia regulators are also involved in responses to antifungal drugs and mediating ergosterol levels. We suggest that pathogenic fungi have developed a coordinated regulatory system in response to hypoxia and iron starvation through (i) regulation of expression of hypoxia-responsive and iron-responsive genes via cross-linked key regulators, and/or (ii) regulation of factors involved in ergosterol biosynthesis. Thus, both oxygen and iron availability are intimately tied with fungal virulence and responses to existing therapeutics and further elucidation of their interrelationship should have significant clinical implications.
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Affiliation(s)
- Dawoon Chung
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth Hanover, NH, USA
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21
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Zhang J, Silao FGS, Bigol UG, Bungay AAC, Nicolas MG, Heitman J, Chen YL. Calcineurin is required for pseudohyphal growth, virulence, and drug resistance in Candida lusitaniae. PLoS One 2012; 7:e44192. [PMID: 22952924 PMCID: PMC3432075 DOI: 10.1371/journal.pone.0044192] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 07/30/2012] [Indexed: 11/19/2022] Open
Abstract
Candida lusitaniae is an emerging fungal pathogen that infects immunocompromised patients including HIV/AIDS, cancer, and neonatal pediatric patients. Though less prevalent than other Candida species, C. lusitaniae is unique in its ability to develop resistance to amphotericin B. We investigated the role of the calcium-activated protein phosphatase calcineurin in several virulence attributes of C. lusitaniae including pseudohyphal growth, serum survival, and growth at 37°C. We found that calcineurin and Crz1, a C. albicans Crz1 homolog acting as a downstream target of calcineurin, are required for C. lusitaniae pseudohyphal growth, a process for which the underlying mechanism remains largely unknown in C. lusitaniae but hyphal growth is fundamental to C. albicans virulence. We demonstrate that calcineurin is required for cell wall integrity, ER stress response, optimal growth in serum, virulence in a murine systemic infection model, and antifungal drug tolerance in C. lusitaniae. To further examine the potential of targeting the calcineurin signaling cascade for antifungal drug development, we examined the activity of a calcineurin inhibitor FK506 in combination with caspofungin against echinocandin resistant C. lusitaniae clinical isolates. Broth microdilution and drug disk diffusion assays demonstrate that FK506 has synergistic fungicidal activity with caspofungin against echinocandin resistant isolates. Our findings reveal that pseudohyphal growth is controlled by the calcineurin signaling cascade, and highlight the potential use of calcineurin inhibitors and caspofungin for emerging drug-resistant C. lusitaniae infections.
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Affiliation(s)
- Jing Zhang
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America
- Department of Chemistry, Duke University, Durham, North Carolina, United States of America
| | - Fitz Gerald S. Silao
- Department of Microbiology and Parasitology, University of Perpetual Help – Dr. Jose G. Tamayo Medical University, Biñan, Laguna, Philippines
| | - Ursela G. Bigol
- Environment and Biotechnology Division, Department of Science and Technology, Bicutan, Philippines
| | - Alice Alma C. Bungay
- Department of Microbiology and Parasitology, University of Perpetual Help – Dr. Jose G. Tamayo Medical University, Biñan, Laguna, Philippines
- National Institutes of Health-Philippines, University of the Philippines, Manila, Philippines
| | - Marilou G. Nicolas
- National Institutes of Health-Philippines, University of the Philippines, Manila, Philippines
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America
- * E-mail: (JH); (Y-LC)
| | - Ying-Lien Chen
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, United States of America
- * E-mail: (JH); (Y-LC)
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Gao N, Kumar A, Guo H, Wu X, Wheater M, Yu FSX. Topical flagellin-mediated innate defense against Candida albicans keratitis. Invest Ophthalmol Vis Sci 2011; 52:3074-82. [PMID: 21310913 DOI: 10.1167/iovs.10-5928] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE This study was conducted to investigate whether flagellin, the sole ligand of Toll-like receptor-5 (TLR5), induces an innate defense that is sufficient to protect injured corneas from Candida albicans. METHODS Scarified corneas of adult B6, TLR5(-/-), Camp(-/-) (cathelicidin-related antimicrobial peptide), or PMN-depleted mice were pretreated with Pseudomonas aeruginosa flagellin or a mutant and then were inoculated with C. albicans. The corneas were compared for disease progression, cytokine and Camp expression, and PMN infiltration before and after C. albicans infection. Disease progress was recorded by digital photography and clinical scoring, cytokine levels were determined by ELISA, the levels of Camp gene product were assessed by Western blot, and PMN infiltration was measured by MPO determination and immunohistochemistry. RESULTS Topical application of flagellin induced profound protection against Candida keratitis in a TLR5-dependent manner. The improved disease outcome including reduced tissue inflammation and rapid functional recovery can be attributed to a marked decrease in fungal burden at the early stage of C. albicans infection in flagellin-exposed B6 mouse corneas. Although both PMN infiltration and Camp upregulation contributed to corneal innate defense against fungal infection, Camp ablation totally, and PMN depletion partially, abrogated flagellin-induced fungal clearance in B6 mouse corneas. CONCLUSIONS Flagellin induces a strong innate defense and promotes robust resistance to C. albicans infection in the cornea. Topical flagellin or its mimetic may become a new prophylactic agent for preventing contact lens or trauma/injury-associated microbial keratitis.
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Affiliation(s)
- Nan Gao
- Department of Ophthalmology, Kresge Eye Institute, Wayne State University School of Medicine, Detroit, Michigan, USA
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Messier C, Epifano F, Genovese S, Grenier D. Inhibition of Candida albicans biofilm formation and yeast-hyphal transition by 4-hydroxycordoin. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2011; 18:380-383. [PMID: 21353508 DOI: 10.1016/j.phymed.2011.01.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Accepted: 01/15/2011] [Indexed: 05/30/2023]
Abstract
Candida albicans distinguishing features such as dimorphism and biofilm formation are thought to play a key role in oral tissue invasion and resistance to host defences and antifungal agents. In this study, we investigated the effect of 4-hydroxycordoin, a natural isopentenyloxychalcone, on growth, biofilm formation and yeast-hyphal transition of C. albicans. Serial dilutions of 4-hydroxycordoin in YNB medium were prepared in microplates to determine minimal inhibitory concentrations (MIC) and effects on biofilm formation for two strains of C. albicans. 4-Hydroxycordoin at up to 200 μg/ml had no effect on growth of C. albicans. Biofilm formation was strongly inhibited (>85%) by 4-hydroxycordoin at 20 μg/ml, while concentrations ranging from 50 to 200 μg/ml caused a significant inhibition of yeast-hyphal transition, as determined by microscopic observation. In conclusion, 4-hydroxycordoin exerts inhibitory effects on two important virulence factors of C. albicans: biofilm formation or yeast-hyphal transition. This suggests that 4-hydroxycordoin may have a therapeutic potential for C. albicans infections.
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Affiliation(s)
- Céline Messier
- Groupe de Recherche en Écologie Buccale, Faculté de Médecine Dentaire, Université Laval, Quebec City, Quebec, Canada
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Hua X, Yuan X, Di Pietro A, Wilhelmus KR. The molecular pathogenicity of Fusarium keratitis: a fungal transcriptional regulator promotes hyphal penetration of the cornea. Cornea 2010; 29:1440-4. [PMID: 20856109 PMCID: PMC2991523 DOI: 10.1097/ico.0b013e3181d8383a] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
PURPOSE The pathogenic mechanisms of fungal infection during human keratomycosis were investigated in an ex vivo corneal model that used strains of Fusarium oxysporum differing in the production of a fungal transcription factor. METHODS A pacC loss-of-function mutant and a pacC dominant-activating mutant were constructed from a wild-type isolate of F. oxysporum, and the 3 strains were characterized by in vitro growth kinetics. Twenty-seven human donor corneas maintained in tissue culture were superficially scarified and topically inoculated with the wild-type, the pacC loss-of-function mutant, or the pacC dominant-activating strains. Relative hyphal invasion into the stroma was compared histopathologically in corneal sections. RESULTS F. oxysporum strains demonstrated comparable exponential growth rates in vitro. Wild-type F. oxysporum invaded into the corneal tissue within 1 day and penetrated through the anterior stroma during the next 4 days. The pacC loss-of-function mutant invaded explanted corneas significantly less than the wild-type strain on day 1 (P < 0.0001) and on day 3 (P = 0.0003). The pacC dominant-activating strain adhered and penetrated explanted corneas similar to the wild-type strain. CONCLUSIONS The PacC pathway regulating the transcription of fungal genes allows fungal adaptation to the ocular surface and enables invasion of the injured cornea by F. oxysporum.
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Affiliation(s)
- Xia Hua
- Sid W. Richardson Ocular Microbiology Laboratory, Department of Ophthalmology, Baylor College of Medicine, Houston, TX 77030, USA
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Yuan X, Mitchell BM, Hua X, Davis DA, Wilhelmus KR. The RIM101 signal transduction pathway regulates Candida albicans virulence during experimental keratomycosis. Invest Ophthalmol Vis Sci 2010; 51:4668-76. [PMID: 20375342 DOI: 10.1167/iovs.09-4726] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
PURPOSE To examine the role of the fungal RIM101 signal transduction pathway in the pathogenesis of Candida albicans keratitis. METHODS C. albicans wild-type strain SC5314, prototrophic mutant control DAY185, and homozygous fungal mutants for the rim8, rim13, rim20, rim101, and phr1 genes were evaluated in vitro using proliferation and filamentation assays. Scarified corneas of BALB/c and C57BL/6J mice were topically inoculated and observed daily for keratitis severity. Corneal adaptation and pathogenicity were assessed ex vivo by maintaining infected porcine corneas for 3 days in an explantation culture system for histologic evaluation of hyphal penetration. RESULTS All C. albicans strains had similar growth kinetics, and SC5314 and DAY185 demonstrated pH-induced filamentation. Fungal mutants had reduced hyphal formation at alkaline and neutral pH, but normal acidic assays ascertained that mutant strains did not have a generalized filamentation defect. SC5314 and DAY185 caused moderate to severe keratitis in mice, whereas fungal strains lacking constituents of the RIM101 pathway had significantly (P<0.05) attenuated severity in vivo. Three days after inoculation of porcine corneas, SC5314 and DAY185 produced hyphae that penetrated 28% and 25%, respectively, of the corneal thickness, and all five mutant strains showed significantly (P<0.05) less stromal penetration. CONCLUSIONS The RIM101 signal transduction pathway plays an important role in the development of C. albicans keratitis. The fungal pathway intermediates Rim8p, Rim13p, Rim20p, and Rim101p and the downstream cell-wall protein Phr1p are pivotal in the process of corneal invasion by C. albicans.
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Affiliation(s)
- Xiaoyong Yuan
- Sid W. Richardson Ocular Microbiology Laboratory, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas 77030, USA
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Yuan X, Hua X, Wilhelmus KR. Proinflammatory chemokines during Candida albicans keratitis. Exp Eye Res 2009; 90:413-9. [PMID: 20005222 DOI: 10.1016/j.exer.2009.12.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2009] [Revised: 12/01/2009] [Accepted: 12/02/2009] [Indexed: 01/07/2023]
Abstract
Chemotactic cytokines mediate the recruitment of leukocytes into infected tissues. This study investigated the profile of chemokines during experimental Candida albicans keratitis and determined the effects of chemokine inhibition on leukocyte infiltration and fungal growth during murine keratomycosis. Scarified corneas of BALB/c mice were topically inoculated with C. albicans and monitored daily over one week for fungal keratitis. After a gene microarray for murine chemokines compared infected corneas to controls, real-time reverse transcription polymerase chain reaction (RT-PCR) and immunostaining assessed chemokine expression in infected and mock-inoculated corneas. An anti-chemokine antibody was then administered subconjunctivally and evaluated for effects on clinical severity, corneal inflammation, fungal recovery, and cytokine expression. Of 33 chemokine genes examined by microarray, 6 CC chemokines and 6 CXC chemokines were significantly (P<0.05) upregulated more than two-fold. Chemokine (CC-motif) ligand 3 (CCL3) was upregulated 108-fold (P=0.03) by real-time RT-PCR within one day after fungal inoculation and remained increased 28-fold (P=0.02) at one week, and its in situ expression increased in the epithelium and stroma of infected corneas. Compared to the control antibody-treated group, eyes treated with anti-CCL3 antibody showed reduced clinical severity (P<0.05), less corneal neovascularization (P=0.02), and fewer inflammatory cells infiltrating corneal tissue, but the amount of recoverable fungi was not significantly (P=0.4) affected. Anti-CCL3 treatment significantly (P=0.01) reduced the expression of tumor necrosis factor and interleukin-1beta in infected corneas. These results indicate that chemokines, especially the CC chemokine CCL3, play important roles in the acute inflammatory response to C. albicans corneal infection.
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Affiliation(s)
- Xiaoyong Yuan
- Sid W. Richardson Ocular Microbiology Laboratory, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, 6565 Fannin St., Houston, TX 77030, USA
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Yuan X, Wilhelmus KR. Toll-like receptors involved in the pathogenesis of experimental Candida albicans keratitis. Invest Ophthalmol Vis Sci 2009; 51:2094-100. [PMID: 19933194 DOI: 10.1167/iovs.09-4330] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Purpose. To investigate the expression and function of toll-like receptors (TLRs) during experimental keratomycosis. Methods. Scarified corneas of BALB/c mice were topically inoculated with Candida albicans and compared with control corneas by a murine gene microarray and immunostaining. Real-time reverse transcription polymerase chain reaction (RT-PCR) determined relative TLR gene expression in murine and human donor corneas. The scarified corneas of TLR2(-/-) mice, TLR4(-/-) mice, and C57BL/6J control mice were also inoculated with C. albicans, to determine relative severity, fungal load, and cytokine transcript levels. Results. TLR1, -2, -4, -6, and -13 were significantly upregulated (5- to 10-fold; P < 0.01) by microarray, and TLR1, -2, -4, and -13 were significantly increased (4- to 11-fold; P < 0.05) by real-time RT-PCR in BALB/c murine corneas. Similarly, TLR2, -6, and -13 were significantly upregulated (5- to 16-fold; P < or = 0.001) by real-time RT-PCR in C57BL/6J murine corneas the day after inoculation, and TLR2 and -13 remained significantly (P < 0.05) increased after 1 week. TLR2 transcript was also upregulated twofold (P = 0.04) in C. albicans-inoculated explanted human corneas. Although murine keratitis severity scores were similar, significantly more fungi were recovered from TLR2(-/-) mouse corneas (P = 0.04) than from TLR4(-/-) mouse corneas (P = 0.9). Tumor necrosis factor-alpha, interleukin 23, chemokine C-C ligands 3 and 4, and dectin-1 were significantly (P < 0.05) downregulated in C. albicans-infected corneas of TLR2(-/-) mice. Conclusions. TLR2 signals proinflammatory cytokines that control fungal growth during C. albicans keratitis. TLR13 may have an additional role in the innate immune response of murine corneal candidiasis.
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Affiliation(s)
- Xiaoyong Yuan
- Sid W. Richardson Ocular Microbiology Laboratory, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA
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Hua X, Yuan X, Mitchell BM, Lorenz MC, O’Day DM, Wilhelmus KR. Morphogenic and genetic differences between Candida albicans strains are associated with keratomycosis virulence. Mol Vis 2009; 15:1476-84. [PMID: 19649176 PMCID: PMC2718853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Accepted: 07/27/2009] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To correlate the morphogenic and molecular traits that affect fungal virulence in human corneas. METHODS C. albicans wild-type strains SC5314 and VE175 were compared using in vitro growth kinetics, filamentation assays, and microarray analysis. Corneal virulence was assessed ex vivo by inoculating C. albicans onto superficially scarified human corneas that were processed after 1 and 3 days to measure hyphal penetration. For comparison, DSY459, a C. albicans homozygous deletion mutant deficient in secreted aspartyl proteinases (SAP) 4, 5, and 6, was evaluated. RESULTS C. albicans strain SC5314 was highly filamentous in vitro and more invasive in human corneal explants while VE175 demonstrated limited filamentation and less corneal invasion. Among 6,655 C. albicans genes, 9.0% significantly (p<.05) differed by 2 fold or more between SC5314 and VE175. Genes involved in fungal filamentation that were upregulated in strain SC5314 compared to VE175 included SAP5, SAP6, and other hypha-associated genes. Compared to wild-type strains, DSY459 had intermediate filamentation and stromal penetration. CONCLUSIONS Fungal genes involved in filamentation likely contribute to virulence differences between wild-type strains of C. albicans. The corneal pathogenicity of C. albicans involves the morphogenic transformation of yeasts into hyphae.
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Affiliation(s)
- Xia Hua
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX
| | - Xiaoyong Yuan
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX
| | | | - Michael C. Lorenz
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center at Houston, Houston, TX
| | - Denis M. O’Day
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN
| | - Kirk R. Wilhelmus
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX
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Yuan X, Mitchell BM, Wilhelmus KR. Expression of matrix metalloproteinases during experimental Candida albicans keratitis. Invest Ophthalmol Vis Sci 2009; 50:737-42. [PMID: 19171647 DOI: 10.1167/iovs.08-2390] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
PURPOSE This study was designed to investigate the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) during the inception and progression of experimental keratomycosis. METHODS Scarified corneas of adult BALB/c mice were topically inoculated with Candida albicans strain SC5314 and monitored for disease severity. Infected and mock-infected corneas were compared at 1 day post inoculation (p.i.) with a murine gene microarray. Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) determined MMP and TIMP levels at 1, 3, and 7 days p.i. for infected, mock-infected, and normal corneas. Immunostaining localized target proteins at 1 day p.i. RESULTS Eyes inoculated with C. albicans developed corneal infection with a mean clinical score of 8.2+/-0.8 at 1 day p.i. Compared to controls at 1 day p.i., MMP-8, -9, -10, -12, -13, -19, and TIMP-1 were significantly upregulated from fivefold to 375-fold by microarray and from threefold to 78-fold by real-time RT-PCR. Upregulated MMPs and TIMP-1 in the corneal epithelium and stroma of infected eyes correlated with the influx of acute inflammatory cells. Neither MMP-8 nor -13 expression was affected by mechanical trauma, but both increased >100-fold during the week after the onset of fungal keratitis. TIMP-1 expression rose from 21-fold more than controls at 1 day to 46-fold at 7 days p.i. by RT-PCR. CONCLUSIONS Transcriptional and translational levels of MMP-8, -9, -13, and TIMP-1 increase during the early stages of C. albicans keratitis, confirming findings for MMP-9 and TIMP-1 in other infectious keratitis models and suggesting roles for MMP-8 and -13.
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Affiliation(s)
- Xiaoyong Yuan
- Sid W. Richardson Ocular Microbiology Laboratory, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas 77030, USA
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Clément M, Tremblay J, Lange M, Thibodeau J, Belhumeur P. Purification and identification of bovine cheese whey fatty acids exhibiting in vitro antifungal activity. J Dairy Sci 2008; 91:2535-44. [PMID: 18565910 DOI: 10.3168/jds.2007-0806] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Milk lipids contain several bioactive factors exhibiting antimicrobial activity against bacteria, viruses, and fungi. In the present study, we demonstrate that free fatty acids (FFA) derived from the saponification of bovine whey cream lipids are active in vitro at inhibiting the germination of Candida albicans, a morphological transition associated with pathogenicity. This activity was found to be significantly increased when bovine FFA were enriched in non-straight-chain FFA. At low cell density, this non-straight-chain FFA-enriched fraction was also found to inhibit in a dose-dependant manner the growth of both developmental forms of C. albicans as well as the growth of Aspergillus fumigatus. Using an assay-guided fractionation, the main components responsible for these activities were isolated. On the basis of mass spectroscopic and gas chromatographic analysis, antifungal compounds were identified as capric acid (C10:0), lauroleic acid (C12:1), 11-methyldodecanoic acid (iso-C13:0), myristoleic acid (C14:1n-5), and gamma-linolenic acid (C18:3n-6). The most potent compound was gamma-linolenic acid, with minimal inhibitory concentration values of 5.4 mg/L for C. albicans and 1.3 mg/L for A. fumigatus, in standardized conditions. The results of this study indicate that bovine whey contains bioactive fatty acids exhibiting antifungal activity in vitro against 2 important human fungal pathogens.
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Affiliation(s)
- M Clément
- Département de microbiologie et immunologie, Université de Montréal, C.P. 6128, succ. Centreville, Montréal, Québec, H3C 3J7, Canada.
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John Wiley & Sons, Ltd.. Current awareness on yeast. Yeast 2007. [DOI: 10.1002/yea.1575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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