scholarly journals The antimicrobial peptide MK58911-NH2 acts on planktonic, biofilm and intramacrophage cells of Cryptococcus neoformans

Author(s):  
Junya de Lacorte Singulani ◽  
Lariane Teodoro Oliveira ◽  
Marina Dorisse Ramos ◽  
Nathália Ferreira Fregonezi ◽  
Paulo César Gomes ◽  
...  

Cryptococcosis is associated with high rates of morbidity and mortality, especially in AIDS patients. Its treatment is carried out by combining amphotericin B and azoles or flucytosine, which cause unavoidable toxicity issues to the host. Thus, the urgency in obtaining new antifungals drives the search for antimicrobial peptides (AMPs). This study aimed to extend the understanding of the mechanism of action of an AMP analog from wasps peptide toxins, MK58911-NH2, on Cryptococcus neoformans . It was also evaluated if MK58911-NH2 can act on cryptococcal cells in macrophages, biofilms, and an immersion zebrafish model of infection. Finally, we investigated the structure-antifungal action and the toxicity relation of MK58911-NH2 fragments and a derivative of this peptide (MH58911-NH2). The results demonstrated that MK58911-NH2 did not alter the fluorescence intensity of cell wall - binding dye calcofluor or capsule- binding dye 18b7 antibody-FITC of C. neoformans , but rather reduced the number and size of fungal cells. This activity reduced the fungal burden of C. neoformans both in macrophages and in zebrafish embryos as well as within biofilms. Three fragments of the MK58911-NH2 peptide showed no activity against Cryptococcus or toxicity in lung cells. The derivative peptide MH58911-NH2, in which the lysine residues of MK58911-NH2 were replaced by histidine, reduced the activity against extracellular and intracellular C. neoformans . On the other hand, it was active against biofilm, and reducing toxicity. In summary, the results showed that peptide MK58911-NH2 could be a promising agent against cryptococcosis. The work also opens a perspective for the verification of the antifungal activity of other derivatives.

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 882
Author(s):  
Masood Alam Khan ◽  
Arif Khan ◽  
Mohd Azam ◽  
Khaled S. Allemailem ◽  
Faris Alrumaihi ◽  
...  

Cryptococcus neoformans infections rose sharply due to rapid increase in the numbers of immunocompromised individuals in recent years. Treatment of Cryptococcosis in immunocompromised persons is largely very challenging and hopeless. Hence, this study aimed to determine the activity of ellagic acid (EA) in the treatment of C. neoformans in cyclophosphamide injected leukopenic mice. A liposomal formulation of ellagic acid (Lip-EA) was prepared and characterized, and its antifungal activity was assessed in comparison to fluconazole (FLZ). The efficacy of the drug treatment was tested by assessing survival rate, fungal burden, and histological analysis in lung tissues. The safety of the drug formulations was tested by investigating hepatic, renal function, and antioxidant levels. The results of the present work demonstrated that Lip-EA, not FLZ, effectively eliminated C. neoformans infection in the leukopenic mice. Mice treated with Lip-EA (40 mg/kg) showed 70% survival rate and highly reduced fungal burden in their lung tissues, whereas the mice treated with FLZ (40 mg/kg) had 20% survival rate and greater fungal load in their lungs. Noteworthy, Lip-EA treatment alleviated cyclophosphamide-induced toxicity and restored hepatic and renal function parameters. Moreover, Lip-EA treatment restored the levels of superoxide dismutase and reduced glutathione and catalase in the lung tissues. The effect of FLZ or EA or Lip-EA against C. neoformans infection was assessed by the histological analysis of lung tissues. Lip-EA effectively reduced influx of inflammatory cells, thickening of alveolar walls, congestion, and hemorrhage. The findings of the present study suggest that Lip-EA may prove to be a promising therapeutic formulation against C. neoformans in immunocompromised persons.


Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 8 ◽  
Author(s):  
Mayra Antúnez-Mojica ◽  
Andrés Rojas-Sepúlveda ◽  
Mario Mendieta-Serrano ◽  
Leticia Gonzalez-Maya ◽  
Silvia Marquina ◽  
...  

By using a zebrafish embryo model to guide the chromatographic fractionation of antimitotic secondary metabolites, seven podophyllotoxin-type lignans were isolated from a hydroalcoholic extract obtained from the steam bark of Bursera fagaroides. The compounds were identified as podophyllotoxin (1), β-peltatin-A-methylether (2), 5′-desmethoxy-β-peltatin-A-methylether (3), desmethoxy-yatein (4), desoxypodophyllotoxin (5), burseranin (6), and acetyl podophyllotoxin (7). The biological effects on mitosis, cell migration, and microtubule cytoskeleton remodeling of lignans 1–7 were further evaluated in zebrafish embryos by whole-mount immunolocalization of the mitotic marker phospho-histone H3 and by a tubulin antibody. We found that lignans 1, 2, 4, and 7 induced mitotic arrest, delayed cell migration, and disrupted the microtubule cytoskeleton in zebrafish embryos. Furthermore, microtubule cytoskeleton destabilization was observed also in PC3 cells, except for 7. Therefore, these results demonstrate that the cytotoxic activity of 1, 2, and 4 is mediated by their microtubule-destabilizing activity. In general, the in vivo and in vitro models here used displayed equivalent mitotic effects, which allows us to conclude that the zebrafish model can be a fast and cheap in vivo model that can be used to identify antimitotic natural products through bioassay-guided fractionation.


2010 ◽  
Vol 42 (2) ◽  
pp. 300-309 ◽  
Author(s):  
Jordan T. Shin ◽  
Eugene V. Pomerantsev ◽  
John D. Mably ◽  
Calum A. MacRae

Phenotype-driven screens in larval zebrafish have transformed our understanding of the molecular basis of cardiovascular development. Screens to define the genetic determinants of physiological phenotypes have been slow to materialize as a result of the limited number of validated in vivo assays with relevant dynamic range. To enable rigorous assessment of cardiovascular physiology in living zebrafish embryos, we developed a suite of software tools for the analysis of high-speed video microscopic images and validated these, using established cardiomyopathy models in zebrafish as well as modulation of the nitric oxide (NO) pathway. Quantitative analysis in wild-type fish exposed to NO or in a zebrafish model of dilated cardiomyopathy demonstrated that these tools detect significant differences in ventricular chamber size, ventricular performance, and aortic flow velocity in zebrafish embryos across a large dynamic range. These methods also were able to establish the effects of the classic pharmacological agents isoproterenol, ouabain, and verapamil on cardiovascular physiology in zebrafish embryos. Sequence conservation between zebrafish and mammals of key amino acids in the pharmacological targets of these agents correlated with the functional orthology of the physiological response. These data provide evidence that the quantitative evaluation of subtle physiological differences in zebrafish can be accomplished at a resolution and with a dynamic range comparable to those achieved in mammals and provides a mechanism for genetic and small-molecule dissection of functional pathways in this model organism.


2019 ◽  
Vol 64 (2) ◽  
Author(s):  
Ren-Yi Lu ◽  
Ting-Jun-Hong Ni ◽  
Jing Wu ◽  
Lan Yan ◽  
Quan-Zhen Lv ◽  
...  

ABSTRACT In the past decades, the incidence of cryptococcosis has increased dramatically, which poses a new threat to human health. However, only a few drugs are available for the treatment of cryptococcosis. Here, we described a leading compound, NT-a9, an analogue of isavuconazole, that showed strong antifungal activities in vitro and in vivo. NT-a9 showed a wide range of activities against several pathogenic fungi in vitro, including Cryptococcus neoformans, Cryptococcus gattii, Candida albicans, Candida krusei, Candida tropicalis, Candida glabrata, and Candida parapsilosis, with MICs ranging from 0.002 to 1 μg/ml. In particular, NT-a9 exhibited excellent efficacy against C. neoformans, with a MIC as low as 0.002 μg/ml. NT-a9 treatment resulted in changes in the sterol contents in C. neoformans, similarly to fluconazole. In addition, NT-a9 possessed relatively low cytotoxicity and a high selectivity index. The in vivo efficacy of NT-a9 was assessed using a murine disseminated-cryptococcosis model. Mice were infected intravenously with 1.8 × 106 CFU of C. neoformans strain H99. In the survival study, NT-a9 significantly prolonged the survival times of mice compared with the survival times of the control group or the isavuconazole-, fluconazole-, or amphotericin B-treated groups. Of note, 4 and 8 mg/kg of body weight of NT-a9 rescued all the mice, with a survival rate of 100%. In the fungal-burden study, NT-a9 also significantly reduced the fungal burdens in brains and lungs, while fluconazole and amphotericin B only reduced the fungal burden in lungs. Taken together, these data suggested that NT-a9 is a promising antifungal candidate for the treatment of cryptococcosis infection.


2020 ◽  
Vol 21 (24) ◽  
pp. 9719
Author(s):  
Marco Spreafico ◽  
Eleonora Mangano ◽  
Mara Mazzola ◽  
Clarissa Consolandi ◽  
Roberta Bordoni ◽  
...  

Transcriptional changes normally occur during development but also underlie differences between healthy and pathological conditions. Transcription factors or chromatin modifiers are involved in orchestrating gene activity, such as the cohesin genes and their regulator NIPBL. In our previous studies, using a zebrafish model for nipblb knockdown, we described the effect of nipblb loss-of-function in specific contexts, such as central nervous system development and hematopoiesis. However, the genome-wide transcriptional impact of nipblb loss-of-function in zebrafish embryos at diverse developmental stages remains under investigation. By RNA-seq analyses in zebrafish embryos at 24 h post-fertilization, we examined genome-wide effects of nipblb knockdown on transcriptional programs. Differential gene expression analysis revealed that nipblb loss-of-function has an impact on gene expression at 24 h post fertilization, mainly resulting in gene inactivation. A similar transcriptional effect has also been reported in other organisms, supporting the use of zebrafish as a model to understand the role of Nipbl in gene regulation during early vertebrate development. Moreover, we unraveled a connection between nipblb-dependent differential expression and gene expression patterns of hematological cell populations and AML subtypes, enforcing our previous evidence on the involvement of NIPBL-related transcriptional dysregulation in hematological malignancies.


2007 ◽  
Vol 52 (2) ◽  
pp. 497-504 ◽  
Author(s):  
Woong Sik Jang ◽  
Xuewei Serene Li ◽  
Jianing N. Sun ◽  
Mira Edgerton

ABSTRACT The activity of histatin 5 (Hst 5) against Candida albicans is initiated through cell wall binding, followed by translocation and intracellular targeting. The C. albicans cell wall protein Ssa2 is involved in the transport of Hst 5 into cells as part of cell killing. P-113 (a 12-amino-acid candidacidal active fragment of Hst 5) and P-113Q2.10 (which is inactivated by a glutamine substitution of the Lys residues at positions 2 and 10) were compared for their levels of cell wall binding and intracellular translocation in Candida wild-type (wt) and ssa2Δ strains. Both P-113 and P-113Q2.10 bound to the walls of C. albicans wt and ssa2Δ cells, although the quantity of P-113Q2.10 in cell wall extracts was higher than that of P-113 in both strains. Increasing the extracellular NaCl concentration to 100 mM completely inhibited the cell wall association of both peptides, suggesting that these interactions are primarily ionic. The accumulation of P-113 in the cytosol of wt cells reached maximal levels within 15 min (0.26 μg/107 cells), while ssa2Δ mutant cells had maximal cytosolic levels of less than 0.2 μg/107 cells even after 30 min of incubation. Furthermore, P-113 but not P-113Q2.10 showed specific binding with a peptide array of C. albicans Ssa2p. P-113Q2.10 was not transported into the cytosol of either C. albicans wt or ssa2Δ cells, despite the high levels of cell wall binding, showing that the two cationic lysine residues at positions 2 and 10 in the P-113 peptide are important for transport into the cytosol and that binding and transport are independent functional events.


2020 ◽  
Author(s):  
Josie F Gibson ◽  
Aleksandra Bojarczuk ◽  
Robert J Evans ◽  
Alfred Kamuyango ◽  
Richard Hotham ◽  
...  

AbstractMeningitis caused by infectious pathogens are associated with vessel damage and infarct formation, however the physiological cause is unknown. Cryptococcus neoformans, is a human fungal pathogen and causative agent of cryptococcal meningitis, where vascular events are observed in up to 30% of cases, predominantly in severe infection. Therefore, we aimed to investigate how infection may lead to vessel damage and associated pathogen dissemination using a zebrafish model for in vivo live imaging. We find that cryptococcal cells become trapped within the vasculature (dependent on there size) and proliferate there resulting in vasodilation. Localised cryptococcal growth, originating from a single or small number of cryptococcal cells in the vasculature was associated with sites of dissemination and simultaneously with loss of blood vessel integrity. Using a cell-cell junction tension reporter we identified dissemination from intact blood vessels and where vessel rupture occurred. Finally, we manipulated blood vessel stifness via cell junctions and found increased stiffness resulted in increased dissemination. Therefore, global vascular vasodilation occurs following infection, resulting in increased vessel tension which subsequently increases dissemination events, representing a positive feedback loop. Thus, we identify a mechanism for blood vessel damage during cryptococcal infection that may represent a cause of vascular damage and cortical infarction more generally in infective meningitis.


2021 ◽  
Author(s):  
Kathryn Wright ◽  
Kumudika de Silva ◽  
Karren M. Plain ◽  
Auriol C. Purdie ◽  
Warwick J. Britton ◽  
...  

AbstractRegulation of host microRNA (miRNA) expression is a contested node that controls the host immune response to mycobacterial infection. The host must overcome concerted subversive efforts of pathogenic mycobacteria to launch and maintain a protective immune response. Here we examine the role of miR-126 in the zebrafish model of Mycobacterium marinum infection and identify a protective role for this infection-induced miRNA through multiple effector pathways. Specifically, we analyse the impact of the miR-126 knockdown-induced tsc1a and cxcl12a/ccl2/ccr2 signalling axes during early host-M. marinum interactions. We find a strong detrimental effect of tsc1a upregulation that renders zebrafish embryos susceptible to higher bacterial burden and increased cell death despite dramatically higher recruitment of macrophages to the site of infection. We demonstrate that infection-induced miR-126 suppresses tsc1 and cxcl12a expression thus improving macrophage function early in infection, partially through activation of mTOR signalling and strongly through preventing the recruitment of Ccr2+ permissive macrophages, resulting in the recruitment of protective tnfa-expressing macrophages. Together our results demonstrate an important role for infection-induced miR-126 in shaping an effective immune response to M. marinum infection in zebrafish embryos.


2020 ◽  
Vol 122 (10) ◽  
pp. 3089-3098
Author(s):  
Alya Hanisah Omar ◽  
Chin Siang Kue ◽  
Roza Dianita ◽  
Ke-Xin Yu

PurposeTraditional Malaysian vegetables, also known as ulam, are believed to have healing properties among the local community. Ulam is commonly reported to have high antioxidant content which makes it a popular food. The purpose of this paper is to determine the teratogenic potential of eight ulam, using zebrafish model. The tested ulam were Cosmos caudatus, Gynura procumbens, Labisia pumila var. alata, Phaleria macrocarpa, Polygonum minus, Piper sarmentosum, Premna foetida and Sauropus androgynous.Design/methodology/approachMethanol extract of ulam was prepared using the maceration method. Various concentrations of extracts were tested against fish embryo short-term toxicity test. The lethal concentration (LC50) and teratogenic effect of the ulam were determined.FindingsAmong all tested species, L. pumila, P. foetida and S. androgynous showed 100% lethal effect towards zebrafish embryos at concentrations of 10 µg/mL, 1,000 µg/mL and 100 µg/mL, respectively. The three ulam have exhibited teratogenic effect on zebrafish embryos after 72 h post-fertilization. L. pumila had induced yolk sac edema at 1.0 µg/mL for normalized measurement of 108.3 ± 2.0% (which is higher than negative control, p < 0.05, median = 110.7%), while P. foetida had induced pericardial edema at 100 µg/mL for normalized measurement of 124.0 ± 4.6% (which is higher than negative control, p < 0.05, median = 124.3%). On the other hand, S. androgynus induced curve trunk at 30 µg/mL for the presence of 70.9 ± 4.2%.Originality/valueThe teratogenic effect of L. pumila, P. foetida and S. androgynous suggests the possible disruption in the embryogenesis in zebrafish, namely Notch, vascular endothelial growth factor (VEGF) and retinoic acid pathways. The results of ulam gave possible implications and insights on the cancer pathways involved, which could be a useful target for cancer research. This is the first report on teratogenicity evaluation of Malaysian ulam showing relationship to cancer pathways by using zebrafish embryo model.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 915-915
Author(s):  
Aldo M Roccaro ◽  
Antonio Sacco ◽  
Dongdong Ma ◽  
Jiantao Shi ◽  
Yuji Mishima ◽  
...  

Abstract Multiple myeloma develops from a pre-malignant clonal proliferation of plasma cells. The dissemination of myeloma cells throughout the bone marrow (BM) is an important early step in myeloma pathogenesis. Studies of myeloma cell homing in mouse models are not quantitative and cannot be used for functional genomics or drug screening. To overcome these limitations, we have developed a novel in vivo model to assess multiple myeloma (MM) cell homing, that takes advantage of the optical clarity of zebrafish (Danio rerio) embryos. We performed intra-cardiac (i.c.) injection of GFP+MM.1S cells into zebrafish embryos 48 hpf, and assessed the ability of the injected cells to enter the peripheral circulation and then traced their homing to the trunk region of zebrafish embryos, an area referred as the caudal hematopoietic tissue (CHT), by using intra-vital confocal microscopy. We next injected primary CD138+ cells derived from MM patient BM that had been stained with either DiO or DiD and demonstrated that they also homed to CHT. As a control, we injected DiO-labeled CD41-GFPlow zebrafish hematopoietic stem cells (HSCs) that are known to home to the CHT hematopoietic niche; and observed that zebrafish-derived CD41-HSCs homed to the same area as MM cells. We next analyzed changes in the transcriptome of those MM cells that homed to the CHT-niche. We dissected the zebrafish embryos to separate the CHT from other tissue containing non-adherent MM cells and performed whole human exome enrichment prior to sequencing of total RNA. We had an alignment rate of 10-15%, with a high intragenic rate an exonic rate (> 95%) and a low mismatch rate (~0.5%). RNAseq revealed that the MM cells that homed to the CHT were enriched in transcripts important for cytokine/chemokine mediated signaling, the IL-6 signalling pathway, cell-cell adhesion and angiogenesis (FDR<0.25; P<0.05). Overall, these findings indicate that the changes observed in MM cells that have homed to the CHT mirror those that are seen in MM cells that are resident in the human BM. In order to investigate the functional relevance of the zebrafish model, we established CXCR4-, VLA-4- and FAK-silenced MM cells and compared their ability to home to CHT to that of control scrambled shRNA-transfected cells. DiO-labeled-CXCR4-silenced and DiO-labeled-scrambled-probe control MM cells were mixed in equal numbers and subsequently injected into recipient zebrafish. We found a significant reduction in the number of CXCR4-silenced MM cells homing to the CHT, compared to the control cells (P<0.00). We then examined VLA-4- and FAK-knock-down MM cells and observed that the homing of MM cells to CHT was impaired when either VLA-4 or FAK were silenced (P<0.001; Fig. 3C-D). Having demonstrated the role of CXCF4, FAK and VLA4 in MM cell homing to the CHT niche, we next performed qRT-PCR for those transcripts and confirmed that MM cells harvested from the CHT areas expressed higher levels of CXCR4, FAK and VLA4, compared to MM cells harvested from non-CHT areas. (P<0.05). To ascertain whether homing to zebrafish embryo CHT is occurs in other hematologic malignancies that are known to home to the human and murine BM, we used a cultured cell lined derived from a patient with Waldenstrom's Macroglobulinemia (WM). We injected either CXCR4-overexpressing or CXCR4-silenced WM cells and found that increased CXCR4 expression in WM cells led to enhanced CHT-homing of WM cells (P<0.001), while the homing of CXCR4-silenced WM cells to the CHT was reduced compared to scrambled control (P<0.001). These findings demonstrate that zebrafish can be used to study the homing of human myeloma cells to a hematopoietic niche. The rapidity of homing to CHT, which occurs within seconds of cell injection, suggests that a fraction of the CD138+ harvested from patient bone marrow already express those RNA transcripts and proteins needed for stable adhesion and residence in CHT. This hypothesis is confirmed by the RNA seq and qRT-PCR studies which directly demonstrate increased expression of relevant transcripts in adherent cells. This zebrafish model may provide new insights into the pathogenesis of MM and may be useful as a means to screen for agents which can disrupt homing and dissemination of MM cells. Disclosures No relevant conflicts of interest to declare.


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