1
|
Eigenfeld M, Lupp KFM, Schwaminger SP. Role of Natural Binding Proteins in Therapy and Diagnostics. Life (Basel) 2024; 14:630. [PMID: 38792650 PMCID: PMC11122601 DOI: 10.3390/life14050630] [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: 03/31/2024] [Revised: 05/02/2024] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
This review systematically investigates the critical role of natural binding proteins (NBPs), encompassing DNA-, RNA-, carbohydrate-, fatty acid-, and chitin-binding proteins, in the realms of oncology and diagnostics. In an era where cancer continues to pose significant challenges to healthcare systems worldwide, the innovative exploration of NBPs offers a promising frontier for advancing both the diagnostic accuracy and therapeutic efficacy of cancer management strategies. This manuscript provides an in-depth examination of the unique mechanisms by which NBPs interact with specific molecular targets, highlighting their potential to revolutionize cancer diagnostics and therapy. Furthermore, it discusses the burgeoning research on aptamers, demonstrating their utility as 'nucleic acid antibodies' for targeted therapy and precision diagnostics. Despite the promising applications of NBPs and aptamers in enhancing early cancer detection and developing personalized treatment protocols, this review identifies a critical knowledge gap: the need for comprehensive studies to understand the diverse functionalities and therapeutic potentials of NBPs across different cancer types and diagnostic scenarios. By bridging this gap, this manuscript underscores the importance of NBPs and aptamers in paving the way for next-generation diagnostics and targeted cancer treatments.
Collapse
Affiliation(s)
- Marco Eigenfeld
- Otto-Loewi Research Center, Division of Medicinal Chemistry, Medical University of Graz, Neue Stiftingtalstraße 6, 8010 Graz, Austria
| | - Kilian F. M. Lupp
- Otto-Loewi Research Center, Division of Medicinal Chemistry, Medical University of Graz, Neue Stiftingtalstraße 6, 8010 Graz, Austria
| | - Sebastian P. Schwaminger
- Otto-Loewi Research Center, Division of Medicinal Chemistry, Medical University of Graz, Neue Stiftingtalstraße 6, 8010 Graz, Austria
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| |
Collapse
|
2
|
Kwok ACM, Chan WS, Wong JTY. Dinoflagellate Amphiesmal Dynamics: Cell Wall Deposition with Ecdysis and Cellular Growth. Mar Drugs 2023; 21:md21020070. [PMID: 36827111 PMCID: PMC9959387 DOI: 10.3390/md21020070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/11/2023] [Accepted: 01/17/2023] [Indexed: 01/24/2023] Open
Abstract
Dinoflagellates are a major aquatic protist group with amphiesma, multiple cortical membranous "cell wall" layers that contain large circum-cortical alveolar sacs (AVs). AVs undergo extensive remodeling during cell- and life-cycle transitions, including ecdysal cysts (ECs) and resting cysts that are important in some harmful algal bloom initiation-termination. AVs are large cortical vesicular compartments, within which are elaborate cellulosic thecal plates (CTPs), in thecate species, and the pellicular layer (PL). AV-CTPs provide cellular mechanical protection and are targets of vesicular transport that are replaced during EC-swarmer cell transition, or with increased deposition during the cellular growth cycle. AV-PL exhibits dynamical-replacement with vesicular trafficking that are orchestrated with amphiesmal chlortetracycline-labeled Ca2+ stores signaling, integrating cellular growth with different modes of cell division cycle/progression. We reviewed the dynamics of amphiesma during different cell division cycle modes and life cycle stages, and its multifaceted regulations, focusing on the regulatory and functional readouts, including the coral-zooxanthellae interactions.
Collapse
|
3
|
Wang Y, Jiang L, Zhao Y, Ju X, Wang L, Jin L, Fine RD, Li M. Biological characteristics and pathogenicity of Acanthamoeba. Front Microbiol 2023; 14:1147077. [PMID: 37089530 PMCID: PMC10113681 DOI: 10.3389/fmicb.2023.1147077] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 03/21/2023] [Indexed: 04/25/2023] Open
Abstract
Acanthamoeba is an opportunistic protozoa, which exists widely in nature and is mainly distributed in soil and water. Acanthamoeba usually exists in two forms, trophozoites and cysts. The trophozoite stage is one of growth and reproduction while the cyst stage is characterized by cellular quiescence, commonly resulting in human infection, and the lack of effective monotherapy after initial infection leads to chronic disease. Acanthamoeba can infect several human body tissues such as the skin, cornea, conjunctiva, respiratory tract, and reproductive tract, especially when the tissue barriers are damaged. Furthermore, serious infections can cause Acanthamoeba keratitis, granulomatous amoebic encephalitis, skin, and lung infections. With an increasing number of Acanthamoeba infections in recent years, the pathogenicity of Acanthamoeba is becoming more relevant to mainstream clinical care. This review article will describe the etiological characteristics of Acanthamoeba infection in detail from the aspects of biological characteristic, classification, disease, and pathogenic mechanism in order to provide scientific basis for the diagnosis, treatment, and prevention of Acanthamoeba infection.
Collapse
Affiliation(s)
- Yuehua Wang
- College of Laboratory Medicine, Jilin Medical University, Jilin City, China
| | - Linzhe Jiang
- General Surgery, Jilin People’s Hospital, Jilin City, China
| | - Yitong Zhao
- College of Laboratory Medicine, Jilin Medical University, Jilin City, China
| | - Xiaohong Ju
- College of Laboratory Medicine, Jilin Medical University, Jilin City, China
| | - Le Wang
- Department of Laboratory Medicine, Jilin Hospital of Integrated Chinese and Western Medicine, Jilin City, China
| | - Liang Jin
- Department of Laboratory Medicine, Jilin Hospital of Integrated Chinese and Western Medicine, Jilin City, China
| | - Ryan D. Fine
- Center for Human Genetics and Genomics, New York University Grossman School of Medicine, New York City, NY, United States
| | - Mingguang Li
- College of Laboratory Medicine, Jilin Medical University, Jilin City, China
- *Correspondence: Mingguang Li,
| |
Collapse
|
4
|
Fechtali-Moute Z, Loiseau PM, Pomel S. Stimulation of Acanthamoeba castellanii excystment by enzyme treatment and consequences on trophozoite growth. Front Cell Dev Biol 2022; 10:982897. [PMID: 36172275 PMCID: PMC9511172 DOI: 10.3389/fcell.2022.982897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/17/2022] [Indexed: 11/13/2022] Open
Abstract
Acanthamoeba castellanii is a widespread Free-Living Amoeba (FLA) that can cause severe ocular or cerebral infections in immunocompetent and immunocompromised patients, respectively, besides its capacity to transport diverse pathogens. During their life cycle, FLA can alternate between a vegetative form, called a trophozoite, and a latent and resistant form, called a cyst. This resistant form is characterized by the presence of a cell wall containing two layers, namely the ectocyst and the endocyst, mainly composed of cellulose and proteins. In the present work, we aimed to stimulate Acanthamoeba castellanii excystment by treating their cysts with a cellulolytic enzyme, i.e., cellulase, or two proteolytic enzymes, i.e., collagenase and pepsin. While 11 days were necessary to obtain total excystment in the control at 27°C, only 48 h were sufficient at the same temperature to obtain 100% trophozoites in the presence of 25 U/mL cellulase, 50 U/mL collagenase or 100 U/mL pepsin. Additionally, more than 96% amoebae have excysted after only 24 h with 7.5 U/mL cellulase at 30°C. Nevertheless, no effect of the three enzymes was observed on the excystment of Balamuthia mandrillaris and Vermamoeba vermiformis. Surprisingly, A. castellanii trophozoites excysted in the presence of cellulase displayed a markedly shorter doubling time at 7 h, in comparison to the control at 23 h. Likewise, trophozoites doubled their population in 9 h when both cellulose and cellulase were added to the medium, indicating that Acanthamoeba cyst wall degradation products promote their trophozoite proliferation. The analysis of cysts in epifluorescent microscopy using FITC-lectins and in electron microscopy revealed a disorganized endocyst and a reduction of the intercystic space area after cellulase treatment, implying that these cellular events are preliminary to trophozoite release during excystment. Further studies would be necessary to determine the signaling pathways involved during this amoebal differentiation process to identify new therapeutic targets for the development of anti-acanthamoebal drugs.
Collapse
|
5
|
Amoebae as Targets for Toxins or Effectors Secreted by Mammalian Pathogens. Toxins (Basel) 2021; 13:toxins13080526. [PMID: 34437397 PMCID: PMC8402458 DOI: 10.3390/toxins13080526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/26/2021] [Accepted: 07/26/2021] [Indexed: 11/28/2022] Open
Abstract
Numerous microorganisms, pathogenic for mammals, come from the environment where they encounter predators such as free-living amoebae (FLA). The selective pressure due to this interaction could have generated virulence traits that are deleterious for amoebae and represents a weapon against mammals. Toxins are one of these powerful tools that are essential for bacteria or fungi to survive. Which amoebae are used as a model to study the effects of toxins? What amoeba functions have been reported to be disrupted by toxins and bacterial secreted factors? Do bacteria and fungi effectors affect eukaryotic cells similarly? Here, we review some studies allowing to answer these questions, highlighting the necessity to extend investigations of microbial pathogenicity, from mammals to the environmental reservoir that are amoebae.
Collapse
|
6
|
Garajová M, Mrva M, Vaškovicová N, Martinka M, Melicherová J, Valigurová A. Cellulose fibrils formation and organisation of cytoskeleton during encystment are essential for Acanthamoeba cyst wall architecture. Sci Rep 2019; 9:4466. [PMID: 30872791 PMCID: PMC6418277 DOI: 10.1038/s41598-019-41084-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Accepted: 03/01/2019] [Indexed: 01/26/2023] Open
Abstract
Acanthamoebae success as human pathogens is largely due to the highly resistant cysts which represent a crucial problem in treatment of Acanthamoeba infections. Hence, the study of cyst wall composition and encystment play an important role in finding new therapeutic strategies. For the first time, we detected high activity of cytoskeletal elements - microtubular networks and filamentous actin, in late phases of encystment. Cellulose fibrils - the main components of endocyst were demonstrated in inter-cystic space, and finally in the ectocyst, hereby proving the presence of cellulose in both layers of the cyst wall. We detected clustering of intramembranous particles (IMPs) and their density alterations in cytoplasmic membrane during encystment. We propose a hypothesis that in the phase of endocyst formation, the IMP clusters represent cellulose microfibril terminal complexes involved in cellulose synthesis that after cyst wall completion are reduced. Cyst wall impermeability, due largely to a complex polysaccharide (glycans, mainly cellulose) has been shown to be responsible for Acanthamoeba biocide resistance and cellulose biosynthesis pathway is suggested to be a potential target in treatment of Acanthamoeba infections. Disruption of this pathway would affect the synthesis of cyst wall and reduce considerably the resistance to chemotherapeutic agents.
Collapse
Affiliation(s)
- Mária Garajová
- Department of Zoology, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15, Bratislava, Slovak Republic.
| | - Martin Mrva
- Department of Zoology, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15, Bratislava, Slovak Republic
| | - Naděžda Vaškovicová
- Institute of Scientific Instruments, Czech Academy of Sciences, 612 64, Brno, Czech Republic
| | - Michal Martinka
- Department of Plant Physiology, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15, Bratislava, Slovak Republic
| | - Janka Melicherová
- Department of Botany and Zoology, Faculty of Science, Masaryk University, 611 37, Brno, Czech Republic
| | - Andrea Valigurová
- Department of Botany and Zoology, Faculty of Science, Masaryk University, 611 37, Brno, Czech Republic
| |
Collapse
|
7
|
Impact of Acanthamoeba Cysts on Stress Resistance of Salmonella enterica Serovar Typhimurium, Yersinia enterocolitica 4/O:3, Listeria monocytogenes 1/2a, and Escherichia coli O:26. Appl Environ Microbiol 2017; 83:AEM.00754-17. [PMID: 28526786 DOI: 10.1128/aem.00754-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 05/09/2017] [Indexed: 01/06/2023] Open
Abstract
The formation of robust resting cysts enables Acanthamoeba to resist harsh environmental conditions. This study investigated to what extent these cysts are resistant to physical and chemical stresses as applied in food industry cleaning and disinfection procedures. Moreover, it was assessed whether certain intracystic meat-borne bacterial pathogens are more stress resistant than free-living bacterial monocultures and if intracystic passage and subsequent association with trophozoites induces cross-tolerance toward other stressors. Several physical and chemical stressors (NaCl, H2O2, benzalkonium chloride, 55°C, heating until boiling, ethanol, dishwashing detergent, and sodium hypochlorite) frequently used in domestic and industrial food-related environments were tested against (i) Acanthamoeba castellanii cysts, (ii) single strains of bacterial monocultures, (iii) intracystic bacteria, and (iv) bacteria after intracystic passage (cyst-primed bacteria). Only heating until boiling and hypochlorite treatment were cysticidal. After boiling, no viable trophozoites could be recovered from the cysts, and hypochlorite treatment caused a 1.34- to 4.72-log10 cells/ml reduction in cyst viability. All treatments were effective in reducing or even eliminating the tested bacterial monocultures, whereas bacteria residing inside cysts were more tolerant toward these stressors. All cyst-primed bacteria exhibited an increased tolerance toward subsequent H2O2 (>92% decrease in median log10 CFU/ml reduction) and 70% ethanol (>99% decrease) treatments. Moreover, intracystic passage significantly increased the survival of Yersinia enterocolitica (74% decrease in median log10 reduction), Escherichia coli (58%), and Salmonella enterica (48%) after NaCl treatment and of E. coli (96%), S. enterica (99%), and Listeria monocytogenes (99%) after sodium hypochlorite treatment compared with that of nonprimed bacteria.IMPORTANCE The results from this study demonstrated that both viable and nonviable amoebal cysts can protect internalized bacteria against stressful conditions. Moreover, cyst passage can induce cross-tolerance in bacteria, increasing their survival when exposed to selected stressors. These findings underscore the potential importance of free-living amoebae in food-related environments and their impact on the persistence of meat-borne bacterial pathogens.
Collapse
|
8
|
Lee YR, Na BK, Moon EK, Song SM, Joo SY, Kong HH, Goo YK, Chung DI, Hong Y. Essential Role for an M17 Leucine Aminopeptidase in Encystation of Acanthamoeba castellanii. PLoS One 2015; 10:e0129884. [PMID: 26075721 PMCID: PMC4468156 DOI: 10.1371/journal.pone.0129884] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 05/14/2015] [Indexed: 11/19/2022] Open
Abstract
Encystation of Acanthamoeba leads to the formation of resilient cysts from vegetative trophozoites. This process is essential for parasite survival under unfavorable conditions such as starvation, low temperatures, and exposure to biocides. During encystation, a massive turnover of intracellular components occurs, and a large number of organelles and proteins are degraded by proteases. Previous studies with specific protease inhibitors have shown that cysteine and serine proteases are involved in encystation of Acanthamoeba, but little is known about the role of metalloproteases in this process. Here, we have biochemically characterized an M17 leucine aminopeptidase of Acanthamoeba castellanii (AcLAP) and analyzed its functional involvement in encystation of the parasite. Recombinant AcLAP shared biochemical properties such as optimal pH, requirement of divalent metal ions for activity, substrate specificity for Leu, and inhibition profile by aminopeptidase inhibitors and metal chelators with other characterized M17 family LAPs. AcLAP was highly expressed at a late stage of encystation and mainly localized in the cytoplasm of A. castellanii. Knockdown of AcLAP using small interfering RNA induced a decrease of LAP activity during encystation, a reduction of mature cyst formation, and the formation of abnormal cyst walls. In summary, these results indicate that AcLAP is a typical M17 family enzyme that plays an essential role during encystation of Acanthamoeba.
Collapse
Affiliation(s)
- Yu-Ran Lee
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 700–422, Republic of Korea
| | - Byoung-Kuk Na
- Department of Parasitology and Tropical Medicine, and Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju 660–751, Republic of Korea
| | - Eun-Kyung Moon
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 700–422, Republic of Korea
| | - Su-Min Song
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 700–422, Republic of Korea
| | - So-Young Joo
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 700–422, Republic of Korea
| | - Hyun-Hee Kong
- Department of Parasitology, Dong-A University, College of Medicine, Busan 602–714, Republic of Korea
| | - Youn-Kyoung Goo
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 700–422, Republic of Korea
| | - Dong-Il Chung
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 700–422, Republic of Korea
| | - Yeonchul Hong
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 700–422, Republic of Korea
- * E-mail:
| |
Collapse
|
9
|
Moon EK, Hong Y, Chung DI, Goo YK, Kong HH. Down-regulation of cellulose synthase inhibits the formation of endocysts in Acanthamoeba. THE KOREAN JOURNAL OF PARASITOLOGY 2014; 52:131-5. [PMID: 24850955 PMCID: PMC4028449 DOI: 10.3347/kjp.2014.52.2.131] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 03/03/2014] [Accepted: 03/03/2014] [Indexed: 11/23/2022]
Abstract
Acanthamoeba cysts are resistant to unfavorable physiological conditions and various disinfectants. Acanthamoeba cysts have 2 walls containing various sugar moieties, and in particular, one third of the inner wall is composed of cellulose. In this study, it has been shown that down-regulation of cellulose synthase by small interfering RNA (siRNA) significantly inhibits the formation of mature Acanthamoeba castellanii cysts. Calcofluor white staining and transmission electron microscopy revealed that siRNA transfected amoeba failed to form an inner wall during encystation and thus are likely to be more vulnerable. In addition, the expression of xylose isomerase, which is involved in cyst wall formation, was not altered in cellulose synthase down-regulated amoeba, indicating that cellulose synthase is a crucial factor for inner wall formation by Acanthamoeba during encystation.
Collapse
Affiliation(s)
- Eun-Kyung Moon
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 700-422, Korea
| | - Yeonchul Hong
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 700-422, Korea
| | - Dong-Il Chung
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 700-422, Korea
| | - Youn-Kyoung Goo
- Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 700-422, Korea
| | - Hyun-Hee Kong
- Department of Parasitology, Dong-A University College of Medicine, Busan 602-714, Korea
| |
Collapse
|
10
|
Lacayo CI, Hwang MS, Ding SY, Thelen MP. Lignin depletion enhances the digestibility of cellulose in cultured xylem cells. PLoS One 2013; 8:e68266. [PMID: 23874568 PMCID: PMC3715489 DOI: 10.1371/journal.pone.0068266] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Accepted: 05/23/2013] [Indexed: 01/15/2023] Open
Abstract
Plant lignocellulose constitutes an abundant and sustainable source of polysaccharides that can be converted into biofuels. However, the enzymatic digestion of native plant cell walls is inefficient, presenting a considerable barrier to cost-effective biofuel production. In addition to the insolubility of cellulose and hemicellulose, the tight association of lignin with these polysaccharides intensifies the problem of cell wall recalcitrance. To determine the extent to which lignin influences the enzymatic digestion of cellulose, specifically in secondary walls that contain the majority of cellulose and lignin in plants, we used a model system consisting of cultured xylem cells from Zinniaelegans. Rather than using purified cell wall substrates or plant tissue, we have applied this system to study cell wall degradation because it predominantly consists of homogeneous populations of single cells exhibiting large deposits of lignocellulose. We depleted lignin in these cells by treating with an oxidative chemical or by inhibiting lignin biosynthesis, and then examined the resulting cellulose digestibility and accessibility using a fluorescent cellulose-binding probe. Following cellulase digestion, we measured a significant decrease in relative cellulose content in lignin-depleted cells, whereas cells with intact lignin remained essentially unaltered. We also observed a significant increase in probe binding after lignin depletion, indicating that decreased lignin levels improve cellulose accessibility. These results indicate that lignin depletion considerably enhances the digestibility of cellulose in the cell wall by increasing the susceptibility of cellulose to enzymatic attack. Although other wall components are likely to contribute, our quantitative study exploits cultured Zinnia xylem cells to demonstrate the dominant influence of lignin on the enzymatic digestion of the cell wall. This system is simple enough for quantitative image analysis, but realistic enough to capture the natural complexity of lignocellulose in the plant cell wall. Consequently, these cells represent a suitable model for analyzing native lignocellulose degradation.
Collapse
Affiliation(s)
- Catherine I. Lacayo
- Physical & Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - Mona S. Hwang
- Physical & Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - Shi-You Ding
- Chemical and Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado, United States of America
| | - Michael P. Thelen
- Physical & Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
- * E-mail:
| |
Collapse
|
11
|
Cellular, biochemical, and molecular changes during encystment of free-living amoebae. EUKARYOTIC CELL 2012; 11:382-7. [PMID: 22366126 DOI: 10.1128/ec.05301-11] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Free-living amoebae are protozoa found in soil and water. Among them, some are pathogenic and many have been described as potential reservoirs of pathogenic bacteria. Their cell cycle is divided into at least two forms, the trophozoite and the cyst, and the differentiation process is named encystment. As cysts are more resistant to disinfection treatments than trophozoites, many studies focused on encystment, but until recently, little was known about cellular, biochemical, and molecular modifications operating during this process. Important signals and signaling pathways at play during encystment, as well as cell responses at the molecular level, have been described. This review summarizes our knowledge and focuses on new findings.
Collapse
|
12
|
Blank CE. An expansion of age constraints for microbial clades that lack a conventional fossil record using phylogenomic dating. J Mol Evol 2011; 73:188-208. [PMID: 22105429 DOI: 10.1007/s00239-011-9467-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2011] [Accepted: 10/24/2011] [Indexed: 01/22/2023]
Abstract
Most microbial taxa lack a conventional microfossil or biomarker record, and so we currently have little information regarding how old most microbial clades and their associated traits are. Building on the previously published oxygen age constraint, two new age constraints are proposed based on the ability of microbial clades to metabolize chitin and aromatic compounds derived from lignin. Using the archaeal domain of life as a test case, phylogenetic analyses, along with published metabolic and genetic data, showed that members of the Halobacteriales and Thermococcales are able to metabolize chitin. Ancestral state reconstruction combined with phylogenetic analysis of the genes underlying chitin degradation predicted that the ancestors of these two groups were also likely able to metabolize chitin or chitin-related compounds. These two clades were therefore assigned a maximum age of 1.0 Ga (when chitin likely first appeared). Similar analyses also predicted that the ancestor to the Sulfolobus solfataricus-Sulfolobus islandicus clade was able to metabolize phenol using catechol dioxygenase, so this clade was assigned a maximum age of 475 Ma. Inferred ages of archaeal clades using relaxed molecular clocks with the new age constraints were consistent with those inferred with the oxygen age constraints. This work expands our current toolkit to include Paleoproterozoic, Neoproterozoic, and Paleozoic age constraints, and should aid in our ability to phylogenetically reconstruct the antiquity of a wide array of microbial clades and their associated morphological and biogeochemical traits, spanning deep geologic time. Such hypotheses-although built upon evolutionary inferences-are fundamentally testable.
Collapse
Affiliation(s)
- Carrine E Blank
- Department of Geosciences, University of Montana, 32 Campus Drive #1296, Missoula, MT 59812-1296, USA.
| |
Collapse
|
13
|
Chávez-Munguía B, Segovia-Gamboa N, Salazar-Villatoro L, Omaña-Molina M, Espinosa-Cantellano M, Martínez-Palomo A. Naegleria fowleri: enolase is expressed during cyst differentiation. J Eukaryot Microbiol 2011; 58:463-8. [PMID: 21895838 DOI: 10.1111/j.1550-7408.2011.00574.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cysts of Naegleria fowleri present an external single-layered cyst wall. To date, little information exists on the biochemical components of this cyst wall. Knowledge of the cyst wall composition is important to understand its resistance capacity under adverse environmental conditions. We have used of a monoclonal antibody (B4F2 mAb) that specifically recognizes enolase in the cyst wall of Entamoeba invadens. By Western blot assays this antibody recognized in soluble extracts of N. fowleri cysts a 48-kDa protein with similar molecular weight to the enolase reported in E. invadens cysts. Immunofluorescence with the B4F2 mAb revealed positive cytoplasmic vesicles in encysting amebas, as well as a positive reaction at the cell wall of mature cysts. Immunoelectron microscopy using the same monoclonal antibody confirmed the presence of enolase in the cell wall of N. fowleri cysts and in cytoplasmic vesicular structures. In addition, the B4F2 mAb had a clear inhibitory effect on encystation of N. fowleri.
Collapse
Affiliation(s)
- Bibiana Chávez-Munguía
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies, Avenue IPN 2508, Zacatenco, 07360 Mexico City, Mexico.
| | | | | | | | | | | |
Collapse
|
14
|
Characterization of Thermobifida fusca cutinase-carbohydrate-binding module fusion proteins and their potential application in bioscouring. Appl Environ Microbiol 2010; 76:6870-6. [PMID: 20729325 DOI: 10.1128/aem.00896-10] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cutinase from Thermobifida fusca is thermally stable and has potential application in the bioscouring of cotton in the textile industry. In the present study, the carbohydrate-binding modules (CBMs) from T. fusca cellulase Cel6A (CBM(Cel6A)) and Cellulomonas fimi cellulase CenA (CBM(CenA)) were fused, separately, to the carboxyl terminus of T. fusca cutinase. Both fusion enzymes, cutinase-CBM(Cel6A) and cutinase-CBM(CenA), were expressed in Escherichia coli and purified to homogeneity. Enzyme characterization showed that both displayed similar catalytic properties and pH stabilities in response to T. fusca cutinase. In addition, both fusion proteins displayed an activity half-life of 53 h at their optimal temperature of 50°C. Compared to T. fusca cutinase, in the absence of pectinase, the binding activity on cotton fiber was enhanced by 2% for cutinase-CBM(Cel6A) and by 28% for cutinase-CBM(CenA), whereas in the presence of pectinase, the binding activity was enhanced by 40% for the former and 45% for the latter. Notably, a dramatic increase of up to 3-fold was observed in the amount of released fatty acids from cotton fiber by both cutinase-CBM fusion proteins when acting in concert with pectinase. This is the first report of improving the scouring efficiency of cutinase by fusing it with CBM. The improvement in activity and the strong synergistic effect between the fusion proteins and pectinase suggest that they may have better applications in textile bioscouring than the native cutinase.
Collapse
|
15
|
Quirk A, Lipkowski J, Vandenende C, Cockburn D, Clarke AJ, Dutcher JR, Roscoe SG. Direct visualization of the enzymatic digestion of a single fiber of native cellulose in an aqueous environment by atomic force microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:5007-13. [PMID: 20170174 DOI: 10.1021/la9037028] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Atomic force microscopy (AFM) was used to study native cellulose films prepared from a bacterial cellulose source, Acetobacter xylinum, using a novel application of the Langmuir-Blodgett technique. These films allowed high-resolution AFM images of single fibers and their microfibril structure to be obtained. Two types of experiments were performed. First, the fibers were characterized using samples that were dried after LB deposition. Next, novel protocols that allowed us to image single fibers of cellulose in films that were never dried were developed. This procedure allowed us to perform in situ AFM imaging studies of the enzymatic hydrolysis of single cellulose fibers in solution using cellulolytic enzymes. The in situ degradation of cellulose fibers was monitored over a 9 h period using AFM. These studies provided the first direct, real-time images of the enzymatic degradation of a single cellulose fiber. We have demonstrated the tremendous potential of AFM to study the mechanism of the enzymatic digestion of cellulose and to identify the most effective enzymes for the digestion of various cellulose structures or isomorphs.
Collapse
Affiliation(s)
- Amanda Quirk
- Department of Chemistry, University of Guelph, Guelph, Ontario, N1G 2W1 Canada
| | | | | | | | | | | | | |
Collapse
|
16
|
Lemgruber L, Lupetti P, De Souza W, Vommaro RC, da Rocha-Azevedo B. The fine structure of the Acanthamoeba polyphaga cyst wall. FEMS Microbiol Lett 2010; 305:170-6. [PMID: 20199572 DOI: 10.1111/j.1574-6968.2010.01925.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Members of the genus Acanthamoeba are present in diverse environments, from freshwater to soil, and also in humans, causing serious brain and corneal infections. Their life cycle presents two stages: the dividing trophozoite and the quiescent cyst. The structures of these life stages have been studied for many years, and structural data have been used for taxonomy. The ultrastructural work on Acanthamoeba cysts was carried out previously by routine transmission electron microscopy (TEM), a process that requires the use of chemical fixation, a procedure that can cause serious artifacts in the ultrastructure of the studied material. In order to prevent fixation artifacts, we processed Acanthamoeba polyphaga cysts by ultrarapid freezing, followed by freeze-fracturing and deep-etching, in order to obtain a 3D visualization of the arrangements of the cyst wall. The exocyst presented an irregular surface, with vesicles located within or near this layer. The endocyst, instead, showed a biphasic arrangement with a more compact district in its innermost part, and a more loosened outer layer. For this reason, it was difficult to distinguish the filaments present in the intercyst space from those forming the endocyst. Surprisingly, the intercyst space was thinner when compared with samples processed by conventional TEM, evidencing the possible damage consequent to the use of chemical fixation.
Collapse
Affiliation(s)
- Leandro Lemgruber
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil
| | | | | | | | | |
Collapse
|
17
|
Derda M, Winiecka-Krusnell J, Linder MB, Linder E. Labeled Trichoderma reesei cellulase as a marker for Acanthamoeba cyst wall cellulose in infected tissues. Appl Environ Microbiol 2009; 75:6827-30. [PMID: 19734326 PMCID: PMC2772417 DOI: 10.1128/aem.01555-09] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Accepted: 08/28/2009] [Indexed: 11/20/2022] Open
Abstract
Some protozoans are able to encyst as a protective response to a harmful environment. The cyst wall usually contains chitin as its main structural constituent. Acanthamoeba is an exception since its cyst wall contains cellulose. Specific cytochemical differentiation between cellulose and chitin by microscopy has not been possible due to the similarity of the constituent beta-1,4-linked hexose backbones of these molecules. Thus, various fluorescent brightening agents and lectins bind to both cellulose and chitin. The identification of Acanthamoeba spp., which is based primarily on morphological and biochemical features, is labor-intensive and requires cloning and axenization. We describe a novel immunocytochemical method for identification of Acanthamoeba spp. based on selective binding of Trichoderma reesei cellulase to protozoan cyst wall cellulose. A recombinant cellulose-binding protein consisting of two cellulose-binding domains (CBDs) from T. reesei cellulases was coupled to the fluorescent dyes Alexa Fluor 350 and Alexa Fluor 568 or was labeled with biotin using EZ-Link sulfo-NHS-biotin. No staining reaction was observed with chitin-containing preparations of fungi. Thus, the recombinant CBDs can be used as a marker to distinguish between cellulose and chitin. This allows rapid identification of Acanthamoeba cyst wall cellulose in paraffin or frozen sections of infected tissues.
Collapse
Affiliation(s)
- Monika Derda
- Department of Biology and Medical Parasitology, Poznan University of Medical Sciences, 10 Fredry Street, 61-701 Poznan, Poland.
| | | | | | | |
Collapse
|
18
|
Pearce MM, Cianciotto NP. Legionella pneumophila secretes an endoglucanase that belongs to the family-5 of glycosyl hydrolases and is dependent upon type II secretion. FEMS Microbiol Lett 2009; 300:256-64. [PMID: 19817866 DOI: 10.1111/j.1574-6968.2009.01801.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Examination of cell-free culture supernatants revealed that Legionella pneumophila strains secrete an endoglucanase activity. Legionella pneumophila lspF mutants were deficient for this activity, indicating that the endoglucanase is secreted by the bacterium's type II protein secretion (T2S) system. Inactivation of celA, encoding a member of the family-5 of glycosyl hydrolases, abolished the endoglucanase activity in L. pneumophila culture supernatants. The cloned celA gene conferred activity upon recombinant Escherichia coli. Thus, CelA is the major secreted endoglucanase of L. pneumophila. Mutants inactivated for celA grew normally in protozoa and macrophage, indicating that CelA is not required for the intracellular phase of L. pneumophila. The CelA endoglucanase is one of at least 25 proteins secreted by the type II system of L. pneumophila and the 17th type of enzyme effector associated with this pathway. Only a subset of the other Legionella species tested expressed secreted endoglucanase activity, suggesting that the T2S output differs among the different legionellae. Overall, this study represents the first documentation of an endoglucanase (EC 3.2.1.4) being produced by a strain of Legionella.
Collapse
Affiliation(s)
- Meghan M Pearce
- Department of Microbiology and Immunology, Northwestern University Medical School, 320 East Superior St., Chicago, IL 60611, USA
| | | |
Collapse
|
19
|
Glycogen phosphorylase in Acanthamoeba spp.: determining the role of the enzyme during the encystment process using RNA interference. EUKARYOTIC CELL 2008; 7:509-17. [PMID: 18223117 DOI: 10.1128/ec.00316-07] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Acanthamoeba infections are difficult to treat due to often late diagnosis and the lack of effective and specific therapeutic agents. The most important reason for unsuccessful therapy seems to be the existence of a double-wall cyst stage that is highly resistant to the available treatments, causing reinfections. The major components of the Acanthamoeba cyst wall are acid-resistant proteins and cellulose. The latter has been reported to be the major component of the inner cyst wall. It has been demonstrated previously that glycogen is the main source of free glucose for the synthesis of cellulose in Acanthamoeba, partly as glycogen levels fall during the encystment process. In other lower eukaryotes (e.g., Dictyostelium discoideum), glycogen phosphorylase has been reported to be the main tool used for glycogen breakdown in order to maintain the free glucose levels during the encystment process. Therefore, it was hypothesized that the regulation of the key processes involved in the Acanthamoeba encystment may be similar to the previously reported regulation mechanisms in other lower eukaryotes. The catalytic domain of the glycogen phosphorylase was silenced using RNA interference methods, and the effect of this phenomenon was assessed by light and electron microscopy analyses, calcofluor staining, expression zymogram assays, and Northern and Western blot analyses of both small interfering RNA-treated and control cells. The present report establishes the role of glycogen phosphorylase during the encystment process of Acanthamoeba. Moreover, the obtained results demonstrate that the enzyme is required for cyst wall assembly, mainly for the formation of the cell wall inner layer.
Collapse
|
20
|
Nahm KH. Feed formulations to reduce N excretion and ammonia emission from poultry manure. BIORESOURCE TECHNOLOGY 2007; 98:2282-300. [PMID: 17303412 DOI: 10.1016/j.biortech.2006.07.039] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2005] [Revised: 07/31/2006] [Accepted: 07/31/2006] [Indexed: 05/14/2023]
Abstract
This summary focuses on reducing nitrogen (N) and ammonia emissions from poultry manure through the use of improved amino acid digestibilities and enzyme supplementation. Proper feed processing techniques, phase feeding, and the minimization of feed and water waste can contribute to additional minor reductions in these emissions. Reductions in environmental pollution can be achieved through improved diet formulation based on available nutrients in the ingredients, reducing crude protein (CP) levels and adding synthetic amino acids. Use of amino acid and CP digestibilities can reduce N excretion up to 40% and a 25% increase in N digestibility can be achieved with enzyme supplementation in broiler diets. Digestibilities can be measured by two methods: the excreta and ileal amino acid digestibilities. Both methods allow amino acid levels to be reduced by 10% or more. Enzyme supplementation decreases intestinal viscosity, improves metabolizable energy levels, and increases amino acid digestibilities. Many feed manufacturers still use total amino acid content to formulate feeds. To meet amino acid requirements, crystalline amino acids are needed. The use of feather, meat and bone meal must not be overestimated or underestimated and the limiting amino acids such as cystine, tryptophan, and threonine must be carefully analyzed.
Collapse
Affiliation(s)
- K H Nahm
- Feed and Nutrition Laboratory, College of Life and Environmental Science, Taegu University, Gyong San 712-714, South Korea.
| |
Collapse
|
21
|
DebRoy S, Dao J, Söderberg M, Rossier O, Cianciotto NP. Legionella pneumophila type II secretome reveals unique exoproteins and a chitinase that promotes bacterial persistence in the lung. Proc Natl Acad Sci U S A 2006; 103:19146-51. [PMID: 17148602 PMCID: PMC1748190 DOI: 10.1073/pnas.0608279103] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Type II protein secretion is critical for Legionella pneumophila infection of amoebae, macrophages, and mice. Previously, we found several enzymes to be secreted by this (Lsp) secretory pathway. To better define the L. pneumophila type II secretome, a 2D electrophoresis proteomic approach was used to compare proteins in wild-type and type II mutant supernatants. We identified 20 proteins that are type II-dependent, including aminopeptidases, an RNase, and chitinase, as well as proteins with no homology to known proteins. Because a chitinase had not been previously reported in Legionella, we determined that wild type secretes activity against both p-nitrophenyl triacetyl chitotriose and glycol chitin. An lsp mutant had a 70-75% reduction in activity, confirming the type II dependency of the secreted chitinase. Newly constructed chitinase (chiA) mutants also had approximately 75% less activity, and reintroduction of chiA restored the mutants to normal levels of activity. Although chiA mutants were not impaired for in vitro intracellular infection, they were defective upon intratracheal inoculation into the lungs of A/J mice, and antibodies against ChiA were detectable in infected animals. In contrast, mutants lacking a secreted phosphatase, protease, or one of several lipolytic enzymes were not defective in vivo. In sum, this study shows that the output of type II secretion is greater in magnitude than previously appreciated and includes previously undescribed proteins. Our data also indicate that an enzyme with chitinase activity can promote infection of a mammalian host.
Collapse
Affiliation(s)
- Sruti DebRoy
- Department of Microbiology–Immunology, Northwestern University Medical School, Chicago, IL 60611
| | - Jenny Dao
- Department of Microbiology–Immunology, Northwestern University Medical School, Chicago, IL 60611
| | - Maria Söderberg
- Department of Microbiology–Immunology, Northwestern University Medical School, Chicago, IL 60611
| | - Ombeline Rossier
- Department of Microbiology–Immunology, Northwestern University Medical School, Chicago, IL 60611
| | - Nicholas P. Cianciotto
- Department of Microbiology–Immunology, Northwestern University Medical School, Chicago, IL 60611
- *To whom correspondence should be addressed. E-mail:
| |
Collapse
|
22
|
Gonçalves AB, Santos IM, Paterson RRM, Lima N. FISH and Calcofluor staining techniques to detect in situ filamentous fungal biofilms in water. Rev Iberoam Micol 2006; 23:194-8. [PMID: 17196030 DOI: 10.1016/s1130-1406(06)70044-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Filamentous fungi are a ubiquitous and diverse group of eukaryotic organisms and may contribute, along with bacteria, yeasts, protozoa and viruses, to the formation of biofilms in water distribution systems. However, fungal involvement in biofilms has not been demonstrated unambiguously. Furthermore, these fungi may be responsible for the production of tastes, odours and mycotoxins in drinking water making their early detection important. The detection of fme these problems a combination of two fluorescent techniques for direct detection was tested: (a) Fluorescence In Situ Hybridization (FISH) employing the universal rRNA probe EUK516, labelled with the red Cy3, followed by (b) staining with Calcofluor White MR2 fluorescent dye which stains fungal cell walls blue. Pure cultures of Penicillium brevicompactum were used to establish the methods followed by separate experiments with real water biofilm samples in PVC-C and cast iron coupons. FISH demonstrated eukaryotic microrganisms after approximately 5 h while the calcofluor method revealed chitinous filamentous structures in less than one hour. When the two methods were combined, additional resolution was obtained from the images of filamentous walls (blue) with intact protoplasm (red). In conclusion, FISH and Calcofluor staining provide rapid, direct and unambiguous information on the involvement of ff in biofilms which form in water.
Collapse
Affiliation(s)
- Ana B Gonçalves
- Centro de Engenharia Biológica, and Micoteca da Universidade do Minho, Universidade do Minho, Braga, Portugal
| | | | | | | |
Collapse
|