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Qubais Saeed B, Hamdy R, Akbar N, Sajeevan SE, Khan NA, Soliman SSM. Azole-based compounds as potential anti- Acanthamoeba agents. RSC Med Chem 2024; 15:1578-1588. [PMID: 38784450 PMCID: PMC11110792 DOI: 10.1039/d4md00029c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 02/22/2024] [Indexed: 05/25/2024] Open
Abstract
Acanthamoeba castellanii is an opportunistic pathogen with public health implications, largely due to its invasive nature and non-specific symptoms. Our study focuses on the potential of azole compounds, particularly those with triazole scaffolds, as anti-amoebic agents. Out of 10 compounds, compounds T1 and T8 exhibited effective anti-Acanthamoeba activity with MIC50 values of 125.37 and 143.92 μg mL-1, respectively. Interestingly, compounds T1, T4, T5 and T8 revealed profound anti-excystation activity with MIC50 at 32.01, 85.53, 19.54 and 80.57 μg mL-1, respectively, alongside limited cytotoxicity to human cells. The study underscores the potential of T1, T4, T5, and T8, thiazole-based compounds, as anti-Acanthamoeba agents by both eliminating amoeba viability and preventing excystation, via preserving the amoeba in its latent cyst form, exposing them to elimination by the immune system. Notably, compounds T1, T4, T5, and T8 showed optimal molecular properties, moderate oral bioavailability, and stable complex formation with Acanthamoeba CYP51. They also display superior binding interactions. Further research is needed to understand their mechanisms and optimize their efficacy against Acanthamoeba infections.
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Affiliation(s)
- Balsam Qubais Saeed
- Research Institute of Medical and Health Sciences, University of Sharjah Sharjah 27272 United Arab Emirates
- Department of Clinical Sciences, College of Medicine, University of Sharjah Sharjah 27272 United Arab Emirates
| | - Rania Hamdy
- Research Institute of Medical and Health Sciences, University of Sharjah Sharjah 27272 United Arab Emirates
- Research Institute for Science and Engineering (RISE), University of Sharjah Sharjah 27272 United Arab Emirates
- Faculty of Pharmacy, Zagazig University Zagazig 44519 Egypt
| | - Noor Akbar
- Research Institute of Medical and Health Sciences, University of Sharjah Sharjah 27272 United Arab Emirates
- Department of Clinical Sciences, College of Medicine, University of Sharjah Sharjah 27272 United Arab Emirates
| | | | - Naveed Ahmed Khan
- Microbiota Research Centre, Istinye University Istanbul 34010 Turkey
| | - Sameh S M Soliman
- Research Institute of Medical and Health Sciences, University of Sharjah Sharjah 27272 United Arab Emirates
- Department of Medicinal Chemistry, College of Pharmacy, University of Sharjah Sharjah P.O. Box 27272 United Arab Emirates +97165057472
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2
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Rao K, Abdullah M, Ahmed U, Wehelie HI, Shah MR, Siddiqui R, Khan NA, Alawfi BS, Anwar A. Self-assembled micelles loaded with itraconazole as anti-Acanthamoeba nano-formulation. Arch Microbiol 2024; 206:134. [PMID: 38433145 DOI: 10.1007/s00203-024-03854-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 01/13/2024] [Accepted: 01/17/2024] [Indexed: 03/05/2024]
Abstract
Acanthamoeba castellanii are opportunistic pathogens known to cause infection of the central nervous system termed: granulomatous amoebic encephalitis, that mostly effects immunocompromised individuals, and a sight threatening keratitis, known as Acanthamoeba keratitis, which mostly affects contact lens wearers. The current treatment available is problematic, and is toxic. Herein, an amphiphilic star polymer with AB2 miktoarms [A = hydrophobic poly(ℇ-Caprolacton) and B = hydrophilic poly (ethylene glycol)] was synthesized by ring opening polymerization and CuI catalyzed azide-alkyne cycloaddition. Characterization by 1H and 13C NMR spectroscopy, size-exclusion chromatography and fluorescence spectroscopy was accomplished. The hydrophobic drug itraconazole (ITZ) was incorporated in self-assembled micellar structure of AB2 miktoarms through co-solvent evaporation. The properties of ITZ loaded (ITZ-PCL-PEG2) and blank micelles (PCL-PEG2) were investigated through zeta sizer, scanning electron microscopy and Fourier-transform infrared spectroscopy. Itraconazole alone (ITZ), polymer (DPB-PCL), empty polymeric micelles (PCL-PEG2) alone, and itraconazole loaded in polymeric micelles (ITZ-PCL-PEG2) were tested for anti-amoebic potential against Acanthamoeba, and the cytotoxicity on human cells were determined. The polymer was able to self-assemble in aqueous conditions and exhibited low value for critical micelle concentration (CMC) 0.05-0.06 µg/mL. The maximum entrapment efficiency of ITZ was 68%. Of note, ITZ, DPB, PCL-PEG2 and ITZ-PCL-PEG2 inhibited amoebae trophozoites by 37.34%, 36.30%, 35.77%, and 68.24%, respectively, as compared to controls. Moreover, ITZ-PCL-PEG2 revealed limited cytotoxicity against human keratinocyte cells. These results are indicative that ITZ-PCL-PEG2 micelle show significantly better anti-amoebic effects as compared to ITZ alone and thus should be investigated further in vivo to determine its clinical potential.
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Affiliation(s)
- Komal Rao
- International Center for Chemical and Biological Sciences, HEJ Research Institute of Chemistry, Karachi University, Karachi, 75270, Pakistan
| | - Muhammad Abdullah
- International Center for Chemical and Biological Sciences, HEJ Research Institute of Chemistry, Karachi University, Karachi, 75270, Pakistan
| | - Usman Ahmed
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Hashi Isse Wehelie
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Muhammad Raza Shah
- International Center for Chemical and Biological Sciences, HEJ Research Institute of Chemistry, Karachi University, Karachi, 75270, Pakistan
| | - Ruqaiyyah Siddiqui
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University Edinburgh, Edinburgh, EH14 4AS, UK
- Microbiota Research Center, Istinye University, 34010, Istanbul, Turkey
| | - Naveed A Khan
- Microbiota Research Center, Istinye University, 34010, Istanbul, Turkey.
| | - Bader S Alawfi
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taibah University, 42353, Madinah, Saudi Arabia
| | - Ayaz Anwar
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Subang Jaya, Selangor, Malaysia.
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3
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Gan Q, Cui X, Zhang L, Zhou W, Lu Y. Control Phytophagous Nematodes By Engineering Phytosterol Dealkylation Caenorhabditis elegans as a Model. Mol Biotechnol 2023:10.1007/s12033-023-00869-x. [PMID: 37843756 DOI: 10.1007/s12033-023-00869-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 08/25/2023] [Indexed: 10/17/2023]
Abstract
Plant-parasitic nematodes ingest and convert host phytosterols via dealkylation to cholesterol for both structural and hormonal requirements. The insect 24-dehydrocholesterol reductase (DHCR24) was shown in vitro as a committed enzyme in the dealkylation via chemical blocking. However, an increased brood size and ovulation rate, instead compromised development, were observed in the engineered nematode Caenorhabditis elegans where the DHCR24 gene was knocked down, indicating the relationship between DHCR24 and dealkylation and their function in nematodes remains illusive. In this study, a defect in C. elegans DHCR24 causes impaired growth of the nematode with sitosterol (a major component of phytosterols) as a sole sterol source. Plant sterols with rationally designed structure (null substrates for dealkylation) can't be converted to cholesterol in wild-type worms, and their development was completely halted. This study underpins the essential function of DHCR24 in nematodes and would be beneficial for the development of novel nematocidal strategies.
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Affiliation(s)
- Qinhua Gan
- State Key Laboratory of Marine Resource Utilization in South China Sea, School of Marine Biology and Fisheries, Hainan University, Hainan Province, 570228, Hainan, China
- School of Tropical Agriculture and Forestry, Hainan University, Haikou Province, 570228, Hainan, China
| | - Xinyu Cui
- State Key Laboratory of Marine Resource Utilization in South China Sea, School of Marine Biology and Fisheries, Hainan University, Hainan Province, 570228, Hainan, China
| | - Lin Zhang
- Shandong Rongchen Pharmaceuticals Inc, Qingdao, 266061, China
| | - Wenxu Zhou
- State Key Laboratory of Marine Resource Utilization in South China Sea, School of Marine Biology and Fisheries, Hainan University, Hainan Province, 570228, Hainan, China.
| | - Yandu Lu
- State Key Laboratory of Marine Resource Utilization in South China Sea, School of Marine Biology and Fisheries, Hainan University, Hainan Province, 570228, Hainan, China.
- Key Laboratory of Tropical Hydrobiotechnology of Hainan Province, Hainan University, Haikou, 570228, China.
- Haikou Innovation Center for Research and Utilization of Algal Bioresources, Hainan University, Haikou, 570228, China.
- Hainan Engineering and Research Center of Marine Bioactives & Bioproducts, Hainan University, Haikou, 570228, China.
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4
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Salisbury LJ, Fletcher SJ, Stok JE, Churchman LR, Blanchfield JT, De Voss JJ. Characterization of the cholesterol biosynthetic pathway in Dioscorea transversa. J Biol Chem 2023:104768. [PMID: 37142228 DOI: 10.1016/j.jbc.2023.104768] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/06/2023] Open
Abstract
Cholesterol is the precursor of bioactive plant metabolites such as steroidal saponins. An Australian plant, Dioscorea transversa, produces only two steroidal saponins: 1β-hydroxyprotoneogracillin and protoneogracillin. Here, we used D. transversa as a model in which to elucidate the biosynthetic pathway to cholesterol, a precursor to these compounds. Preliminary transcriptomes of D. transversa rhizome and leaves were constructed, annotated, and analyzed. We identified a novel sterol side chain reductase (SSR) as a key initiator of cholesterol biosynthesis in this plant. By complementation in yeast, we determine that this SSR reduces Δ24,28 double bonds required for phytosterol biogenesis, as well as Δ24,25 double bonds. The latter function is believed to initiate cholesterogenesis by reducing cycloartenol to cycloartanol. Through heterologous expression, purification and enzymatic reconstitution we also demonstrate that the D. transversa sterol demethylase (CYP51) effectively demethylates obtusifoliol, an intermediate of phytosterol biosynthesis and 4-desmethyl-24,25-dihydrolanosterol, a postulated downstream intermediate of cholesterol biosynthesis. In summary, we investigated specific steps of the cholesterol biosynthetic pathway, providing further insight into the downstream production of bioactive steroidal saponin metabolites.
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5
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Steroidal Antimetabolites Protect Mice against Trypanosoma brucei. Molecules 2022; 27:molecules27134088. [PMID: 35807334 PMCID: PMC9268410 DOI: 10.3390/molecules27134088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/14/2022] [Accepted: 06/21/2022] [Indexed: 11/18/2022] Open
Abstract
Trypanosoma brucei, the causative agent for human African trypanosomiasis, is an emerging ergosterol-dependent parasite that produces chokepoint enzymes, sterol methyltransferases (SMT), not synthesized in their animal hosts that can regulate cell viability. Here, we report the lethal effects of two recently described natural product antimetabolites that disrupt Acanthamoeba sterol methylation and growth, cholesta-5,7,22,24-tetraenol (CHT) and ergosta-5,7,22,24(28)-tetraenol (ERGT) that can equally target T. brucei. We found that CHT/ERGT inhibited cell growth in vitro, yielding EC50 values in the low nanomolar range with washout experiments showing cidal activity against the bloodstream form, consistent with their predicted mode of suicide inhibition on SMT activity and ergosterol production. Antimetabolite treatment generated altered T. brucei cell morphology and death rapidly within hours. Notably, in vivo ERGT/CHT protected mice infected with T. brucei, doubling their survival time following daily treatment for 8-10 days at 50 mg/kg or 100 mg/kg. The current study demonstrates a new class of lead antibiotics, in the form of common fungal sterols, for antitrypanosomal drug development.
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Chen H, Verplaetse E, Jauslin T, Cosson P, Slamti L, Lereclus D. The Fate of Bacteria of the Bacillus cereus Group in the Amoeba Environment. MICROBIAL ECOLOGY 2022; 83:1088-1104. [PMID: 34342700 DOI: 10.1007/s00248-021-01828-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 07/21/2021] [Indexed: 06/13/2023]
Abstract
The Bacillus cereus sensu lato group consists of several closely related species, including B. anthracis, B. cereus sensu stricto, and B. thuringiensis. Spores of these pathogenic bacteria are commonly found in the soil but evidence suggests that they are unable to grow in such a natural environment in the absence of nutrient input. Amoebas have been reported to be an amplifier for several species of pathogenic bacteria and their potential involvement to explain the large amount of B. thuringiensis and B. cereus spores in soil has been frequently proposed. Here, we studied the fate of Bacillus and amoebas when cultured together. We show that the virulence factors produced by B. thuringiensis and B. cereus do not affect the amoeba Acanthamoeba castellanii, which, on the contrary, can phagocytose and effectively digest vegetative Bacillus cells to grow and prevent the formation of cysts. Bacterial spores can germinate in the amoeba environment and the vegetative cells can then form chains or aggregates that appear to be less efficiently phagocyted by the amoeba. The use of transcriptional fusions between fluorescent reporter genes and stationary phase- and sporulation-specific promoters showed that the sporulation process occurs more efficiently in the presence of amoebas than in their absence. Moreover, our results showed the amoeba environment to promote spore germination and allow the bacteria to complete their developmental cycle. Overall, this study suggests that the amoeba-Bacillus interaction creates a virtuous circle in which each protagonist helps the other to develop.
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Affiliation(s)
- Haibo Chen
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Emilie Verplaetse
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Tania Jauslin
- Cell Physiology and Metabolism Dpt, Faculty of Medicine, University of Geneva, 1 rue Michel Servet, CH-1211, Geneva 4, Switzerland
| | - Pierre Cosson
- Cell Physiology and Metabolism Dpt, Faculty of Medicine, University of Geneva, 1 rue Michel Servet, CH-1211, Geneva 4, Switzerland
| | - Leyla Slamti
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Didier Lereclus
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France.
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Debnath A. Drug discovery for primary amebic meningoencephalitis: from screen to identification of leads. Expert Rev Anti Infect Ther 2021; 19:1099-1106. [PMID: 33496193 DOI: 10.1080/14787210.2021.1882302] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Introduction: Naegleria fowleri is responsible for primary amebic meningoencephalitis (PAM) which has a fatality rate of >97%. Because of the rarity of the disease, pharmaceutical companies do not pursue new drug discovery for PAM. Yet, it is possible that the infection is underreported and finding a better drug would have an impact on people suffering from this deadly infection.Areas covered: This paper reports the efforts undertaken by different academic groups over the last 20 years to test different compounds against N. fowleri. The drug discovery research encompassed synthesis of new compounds, development and use of high-throughput screening methods and attempts to repurpose clinically developed or FDA-approved compounds for the treatment of PAM.Expert opinion: In absence of economic investment to develop new drugs for PAM, repurposing the FDA-approved drugs has been the best strategy so far to identify new leads against N. fowleri. Increasing use of high-throughput phenotypic screening has the potential to accelerate the identification of new leads, either in monotherapy or in combination treatment. Since phase II clinical trial is not possible for PAM, it is critical to demonstrate in vivo efficacy of a clinically safe compound to translate the discovery from lab to the clinic.
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Affiliation(s)
- Anjan Debnath
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
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In Vitro Effect of Pitavastatin and Its Synergistic Activity with Isavuconazole against Acanthamoeba castellanii. Pathogens 2020; 9:pathogens9090681. [PMID: 32825652 PMCID: PMC7559540 DOI: 10.3390/pathogens9090681] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 08/18/2020] [Accepted: 08/19/2020] [Indexed: 02/06/2023] Open
Abstract
Acanthamoeba keratitis (AK) can occur in healthy individuals wearing contact lenses and it is a painful, blinding infection of the cornea caused by a free-living ameba Acanthamoeba. Current treatment for AK relies on a combination of chlorhexidine, propamidine isethionate, and polyhexamethylene biguanide. However, the current regimen includes an aggressive disinfectant and in 10% of cases recurrent infection ensues. Therefore, development of efficient and safe drugs is a critical unmet need to avert blindness. Acanthamoeba sterol biosynthesis includes two essential enzymes HMG-CoA reductase (HMGR) and sterol 14-demethylase (CYP51), and we earlier identified a CYP51 inhibitor isavuconazole that demonstrated nanomolar potency against A. castellanii trophozoites. In this study, we investigated the effect of well-tolerated HMGR inhibitors and identified pitavastatin that is active against trophozoites of three different clinical strains of A.castellanii. Pitavastatin demonstrated an EC50 of 0.5 to 1.9 µM, depending on strains. Combination of pitavastatin and isavuconazole is synergistic and led to 2- to 9-fold dose reduction for pitavastatin and 11- to 4000-fold dose reduction for isavuconazole to achieve 97% of growth inhibition. Pitavastatin, either alone or in combination with isavuconazole, may lead to repurposing for the treatment of Acanthamoeba keratitis.
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9
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The Delta 5,
7‐Sterols
and Astaxanthin in the Marine Microheterotroph
Schizochytrium
sp.
S31. J AM OIL CHEM SOC 2020. [DOI: 10.1002/aocs.12364] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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10
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The Antifungal Drug Isavuconazole Is both Amebicidal and Cysticidal against Acanthamoeba castellanii. Antimicrob Agents Chemother 2020; 64:AAC.02223-19. [PMID: 32094126 DOI: 10.1128/aac.02223-19] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 02/17/2020] [Indexed: 11/20/2022] Open
Abstract
Current treatments for Acanthamoeba keratitis rely on a combination of chlorhexidine gluconate, propamidine isethionate, and polyhexamethylene biguanide. These disinfectants are nonspecific and inherently toxic, which limits their effectiveness. Furthermore, in 10% of cases, recurrent infection ensues due to the difficulty in killing both trophozoites and double-walled cysts. Therefore, development of efficient, safe, and target-specific drugs which are capable of preventing recurrent Acanthamoeba infection is a critical unmet need for averting blindness. Since both trophozoites and cysts contain specific sets of membrane sterols, we hypothesized that antifungal drugs targeting sterol 14-demethylase (CYP51), known as conazoles, would have deleterious effects on A. castellanii trophozoites and cysts. To test this hypothesis, we first performed a systematic screen of the FDA-approved conazoles against A. castellanii trophozoites using a bioluminescence-based viability assay adapted and optimized for Acanthamoeba The most potent drugs were then evaluated against cysts. Isavuconazole and posaconazole demonstrated low nanomolar potency against trophozoites of three clinical strains of A. castellanii Furthermore, isavuconazole killed trophozoites within 24 h and suppressed excystment of preformed Acanthamoeba cysts into trophozoites. The rapid action of isavuconazole was also evident from the morphological changes at nanomolar drug concentrations causing rounding of trophozoites within 24 h of exposure. Given that isavuconazole has an excellent safety profile, is well tolerated in humans, and blocks A. castellanii excystation, this opens an opportunity for the cost-effective repurposing of isavuconazole for the treatment of primary and recurring Acanthamoeba keratitis.
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Shi D, Chahal KK, Oto P, Nothias LF, Debnath A, McKerrow JH, Podust LM, Abagyan R. Identification of Four Amoebicidal Nontoxic Compounds by a Molecular Docking Screen of Naegleria fowleri Sterol Δ8-Δ7-Isomerase and Phenotypic Assays. ACS Infect Dis 2019; 5:2029-2038. [PMID: 31583882 PMCID: PMC7085920 DOI: 10.1021/acsinfecdis.9b00227] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Naegleria fowleri is a free-living amoeba causing primary amoebic meningoencephalitis, a rapid-onset brain infection in humans with over 97% mortality rate. Despite some progress in the treatment of the disease, there is no single, proven, evidence-based treatment with a high probability of cure. Here we report the chemical library screening and experimental identification of four new compounds with amoebicidal effects against N. fowleri. The chemical library was screened by molecular docking against a homology model of sterol Δ8-Δ7 isomerase (NfERG2). Thirty top-ranking hits were then tested in a cell-based assay for antiproliferative/amoebicidal activities. Eight chemicals exhibited nearly 100% inhibition of N. fowleri at 50 μM, with the EC50 values ranging from 6 to 25 μM. A cell toxicity assay using human HEK-293 cells was also performed. Four of the compounds preferentially kill amoeba cells with no apparent human cell toxicities. These compounds fall into two distinct chemical scaffolds with druglike properties.
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Affiliation(s)
- Da Shi
- Skaggs School of Pharmacy and Pharmaceutical Science, University of California San Diego,9500 Gilman Drive, La Jolla, California, 92093, United States of America
| | - Kirti Kandhwal Chahal
- Skaggs School of Pharmacy and Pharmaceutical Science, University of California San Diego,9500 Gilman Drive, La Jolla, California, 92093, United States of America
- Department of Pharmaceutical Sciences, Guru Jambheshwar University of Science and Technology, Hisar-Delhi Bypass Road, Hisar, Haryana 125001, India
| | - Patricia Oto
- Skaggs School of Pharmacy and Pharmaceutical Science, University of California San Diego,9500 Gilman Drive, La Jolla, California, 92093, United States of America
| | - Louis-Felix Nothias
- Skaggs School of Pharmacy and Pharmaceutical Science, University of California San Diego,9500 Gilman Drive, La Jolla, California, 92093, United States of America
| | - Anjan Debnath
- Skaggs School of Pharmacy and Pharmaceutical Science, University of California San Diego,9500 Gilman Drive, La Jolla, California, 92093, United States of America
| | - James H. McKerrow
- Skaggs School of Pharmacy and Pharmaceutical Science, University of California San Diego,9500 Gilman Drive, La Jolla, California, 92093, United States of America
| | - Larissa M. Podust
- Skaggs School of Pharmacy and Pharmaceutical Science, University of California San Diego,9500 Gilman Drive, La Jolla, California, 92093, United States of America
| | - Ruben Abagyan
- Skaggs School of Pharmacy and Pharmaceutical Science, University of California San Diego,9500 Gilman Drive, La Jolla, California, 92093, United States of America
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A gas chromatography–mass spectrometry-based whole-cell screening assay for target identification in distal cholesterol biosynthesis. Nat Protoc 2019; 14:2546-2570. [DOI: 10.1038/s41596-019-0193-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 05/16/2019] [Indexed: 12/14/2022]
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13
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Zhou W, Ramos E, Zhu X, Fisher PM, Kidane ME, Vanderloop BH, Thomas CD, Yan J, Singha U, Chaudhuri M, Nagel MT, Nes WD. Steroidal antibiotics are antimetabolites of Acanthamoeba steroidogenesis with phylogenetic implications. J Lipid Res 2019; 60:981-994. [PMID: 30709898 PMCID: PMC6495176 DOI: 10.1194/jlr.m091587] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/22/2019] [Indexed: 12/28/2022] Open
Abstract
Pathogenic organisms may be sensitive to inhibitors of sterol biosynthesis, which carry antimetabolite properties, through manipulation of the key enzyme, sterol methyltransferase (SMT). Here, we isolated natural suicide substrates of the ergosterol biosynthesis pathway, cholesta-5,7,22,24-tetraenol (CHT) and ergosta-5,7,22,24(28)-tetraenol (ERGT), and demonstrated their interference in Acanthamoeba castellanii steroidogenesis: CHT and ERGT inhibit trophozoite growth (EC50 of 51 nM) without affecting cultured human cell growth. Washout experiments confirmed that the target for vulnerability was SMT. Chemical, kinetic, and protein-binding studies of inhibitors assayed with 24-AcSMT [catalyzing C28-sterol via Δ24(28)-olefin production] and 28-AcSMT [catalyzing C29-sterol via Δ25(27)-olefin production] revealed interrupted partitioning and irreversible complex formation from the conjugated double bond system in the side chain of either analog, particularly with 28-AcSMT. Replacement of active site Tyr62 with Phe or Leu residues involved in cation-π interactions that model product specificity prevented protein inactivation. The alkylating properties and high selective index of 103 for CHT and ERGT against 28-AcSMT are indicative of a new class of steroidal antibiotic that, as an antimetabolite, can limit sterol expansion across phylogeny and provide a novel scaffold in the design of amoebicidal drugs. Animal studies of these suicide substrates can further explore the potential of their antibiotic properties.
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Affiliation(s)
- Wenxu Zhou
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Emilio Ramos
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Xunlu Zhu
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Paxtyn M Fisher
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Medhanie E Kidane
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Boden H Vanderloop
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Crista D Thomas
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Juqiang Yan
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Ujjal Singha
- Department of Microbiology and Immunology Meharry Medical College, Nashville, TN 37208
| | - Minu Chaudhuri
- Department of Microbiology and Immunology Meharry Medical College, Nashville, TN 37208
| | - Michael T Nagel
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - W David Nes
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409.
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Haubrich BA. Microbial Sterolomics as a Chemical Biology Tool. Molecules 2018; 23:E2768. [PMID: 30366429 PMCID: PMC6278499 DOI: 10.3390/molecules23112768] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 10/23/2018] [Accepted: 10/23/2018] [Indexed: 02/06/2023] Open
Abstract
Metabolomics has become a powerful tool in chemical biology. Profiling the human sterolome has resulted in the discovery of noncanonical sterols, including oxysterols and meiosis-activating sterols. They are important to immune responses and development, and have been reviewed extensively. The triterpenoid metabolite fusidic acid has developed clinical relevance, and many steroidal metabolites from microbial sources possess varying bioactivities. Beyond the prospect of pharmacognostical agents, the profiling of minor metabolites can provide insight into an organism's biosynthesis and phylogeny, as well as inform drug discovery about infectious diseases. This review aims to highlight recent discoveries from detailed sterolomic profiling in microorganisms and their phylogenic and pharmacological implications.
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Affiliation(s)
- Brad A Haubrich
- Department of Chemistry, University of Nevada, Reno, Reno, NV 89557, USA.
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