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ELife Jul 2023Actin dynamics in cell motility, division, and phagocytosis is regulated by complex factors with multiple feedback loops, often leading to emergent dynamic patterns in...
Actin dynamics in cell motility, division, and phagocytosis is regulated by complex factors with multiple feedback loops, often leading to emergent dynamic patterns in the form of propagating waves of actin polymerization activity that are poorly understood. Many in the actin wave community have attempted to discern the underlying mechanisms using experiments and/or mathematical models and theory. Here, we survey methods and hypotheses for actin waves based on signaling networks, mechano-chemical effects, and transport characteristics, with examples drawn from , human neutrophils, , and oocytes. While experimentalists focus on the details of molecular components, theorists pose a central question of universality: Are there generic, model-independent, underlying principles, or just boundless cell-specific details? We argue that mathematical methods are equally important for understanding the emergence, evolution, and persistence of actin waves and conclude with a few challenges for future studies.
Topics: Humans; Actins; Dictyostelium; Cell Movement; Signal Transduction; Phagocytosis; Models, Biological; Actin Cytoskeleton
PubMed: 37428017
DOI: 10.7554/eLife.87181 -
Scientific Reports Aug 2023The role of Blastocystis in intestinal health is an open controversy, and little is known about the potential effect of this microorganism in autoinflammatory diseases...
The role of Blastocystis in intestinal health is an open controversy, and little is known about the potential effect of this microorganism in autoinflammatory diseases such as spondyloarthritis (SpA). Here, we analyzed the gut microbiome of 36 SpA patients and 13 control individuals and demonstrated that the richness, diversity, and taxonomic composition between these two groups are different. We also showed that colonization by Blastocystis in control individuals increases the richness and diversity of the intestinal microbiome, whereas in SpA patients, it does not seem to have any impact. This may reflect a potential role of Blastocystis in sculpting the gut microbiome architecture in control individuals, whereas in subjects with SpA, the modulation of the microbiome may be governed by disease-dependent factors that cannot be overcome by Blastocystis. Regarding taxonomic characterization, SpA patients colonized by Blastocystis showed significant increases in the phylum Pseudomonadota, class Gammaproteobacteria, family Succinivibrionaceae, and genus Succinivibrio. Simultaneously, there were significant increases in the class Bacilli, order Lactobacillales, families Lactobacillaceae and Clostridiaceae, and genera Lactobacillus and Clostridium in non-colonized SpA patients. On the other hand, PICRUSt analysis in Blastocystis-positive SpA patients showed elevations in pathways that may enhance antioxidant capacities and alleviate intestinal inflammation, while Blastocystis-negative SpA patients showed significant changes in pathways that promote cell division/proliferation and can lead to larger changes in the gut microbiome. Our analyses lead us to believe that these changes in the gut microbiome of SpA patients may trigger protective mechanisms as an initial response to inflammation in an attempt to restore balance in the intestinal environment.
Topics: Humans; Gastrointestinal Microbiome; Spondylarthritis; Microbiota; Inflammation; Blastocystis
PubMed: 37596338
DOI: 10.1038/s41598-023-39055-z -
Medicina (Kaunas, Lithuania) Apr 2024The oral cavity is a habitat to a diverse range of organisms that make up an essential element of the human microbiota. There are up to 1000 species of micro-organisms... (Meta-Analysis)
Meta-Analysis Review
The oral cavity is a habitat to a diverse range of organisms that make up an essential element of the human microbiota. There are up to 1000 species of micro-organisms capable of colonizing the mouth. Thirty percent of them are uncultivable. The genus Entamoeba includes several species, out of which at least seven of them are able to inhabit the human body (, , , , , , ). It was shown that only is able to colonize the oral cavity. The aim of this study was to evaluate the association and prevalence of in periodontal disease using two electronic database search engines. In order to have a broader view of the subject, a comprehensive manual search was conducted between 15th February 2023 and 1 April 2023 on these content aggregators and the initial search resulted in 277 articles using the keywords "", "periodontitis", "", "periodontal disease", "prevalence", and "incidence", in different combinations. The results showed that 755 patients were infected with out of a total number of 1729 patients diagnosed with periodontal disease, indicating a global prevalence of 43% in the set of patients analyzed. was prevalent in 58% of the patients that had gingivitis and in 44% of the patients with periodontitis. Prevalence of based on gender was 43% in female patients and 47% in male patients. The results indicate that the higher incidence of in people with periodontal disease compared to healthy people is more than just a sign of the disease; it could also be linked to the severity of the condition and the disease propensity to progress.
Topics: Humans; Entamoeba; Periodontal Diseases; Entamoebiasis; Prevalence; Female; Male
PubMed: 38792919
DOI: 10.3390/medicina60050736 -
The Journal of Biological Chemistry Dec 2023Legionella pneumophila is an environmental bacterium, which replicates in amoeba but also in macrophages, and causes a life-threatening pneumonia called Legionnaires'...
Legionella pneumophila is an environmental bacterium, which replicates in amoeba but also in macrophages, and causes a life-threatening pneumonia called Legionnaires' disease. The opportunistic pathogen employs the α-hydroxy-ketone compound Legionella autoinducer-1 (LAI-1) for intraspecies and interkingdom signaling. LAI-1 is produced by the autoinducer synthase Legionella quorum sensing A (LqsA), but it is not known, how LAI-1 is released by the pathogen. Here, we use a Vibrio cholerae luminescence reporter strain and liquid chromatography-tandem mass spectrometry to detect bacteria-produced and synthetic LAI-1. Ectopic production of LqsA in Escherichia coli generated LAI-1, which partitions to outer membrane vesicles (OMVs) and increases OMV size. These E. coli OMVs trigger luminescence of the V. cholerae reporter strain and inhibit the migration of Dictyostelium discoideum amoeba. Overexpression of lqsA in L.pneumophila under the control of strong stationary phase promoters (P or P), but not under control of its endogenous promoter (P), produces LAI-1, which is detected in purified OMVs. These L. pneumophila OMVs trigger luminescence of the Vibrio reporter strain and inhibit D. discoideum migration. L. pneumophila OMVs are smaller upon overexpression of lqsA or upon addition of LAI-1 to growing bacteria, and therefore, LqsA affects OMV production. The overexpression of lqsA but not a catalytically inactive mutant promotes intracellular replication of L. pneumophila in macrophages, indicating that intracellularly produced LA1-1 modulates the interaction in favor of the pathogen. Taken together, we provide evidence that L. pneumophila LAI-1 is secreted through OMVs and promotes interbacterial communication and interactions with eukaryotic host cells.
Topics: Humans; Bacterial Proteins; Dictyostelium; Escherichia coli; Legionella; Legionella pneumophila; Legionnaires' Disease; Quorum Sensing
PubMed: 37866633
DOI: 10.1016/j.jbc.2023.105376 -
Microorganisms Oct 2023The presence of microbial communities on cave walls and speleothems is an issue that requires attention. Traditional cleaning methods using water, brushes, and steam can...
16S and 18S rDNA Amplicon Sequencing Analysis of Aesthetically Problematic Microbial Mats on the Walls of the Petralona Cave: The Use of Essential Oils as a Cleaning Method.
The presence of microbial communities on cave walls and speleothems is an issue that requires attention. Traditional cleaning methods using water, brushes, and steam can spread the infection and cause damage to the cave structures, while chemical agents can lead to the formation of toxic compounds and damage the cave walls. Essential oils (EOs) have shown promising results in disrupting the cell membrane of bacteria and affecting their membrane permeability. In this study, we identified the microorganisms forming unwanted microbial communities on the walls and speleothems of Petralona Cave using 16S and 18S rDNA amplicon sequencing approaches and evaluated the efficacy of EOs in reducing the ATP levels of these ecosystems. The samples exhibited a variety of both prokaryotic and eukaryotic microorganisms, including , , , , , the SAR supergroup, , , , and . These phyla are often found in various habitats, including caves, and contribute to the ecological intricacy of cave ecosystems. In terms of the order and genus taxonomy, the identified biota showed abundances that varied significantly among the samples. Functional predictions were also conducted to estimate the differences in expressed genes among the samples. Oregano EO was found to reduce ATP levels by 87% and 46% for black and green spots, respectively. Consecutive spraying with cinnamon EO further reduced ATP levels, with reductions of 89% for black and 88% for green spots. The application of a mixture solution caused a significant reduction up to 96% in ATP levels of both areas. Our results indicate that EOs could be a promising solution for the treatment of microbial communities on cave walls and speleothems.
PubMed: 38004693
DOI: 10.3390/microorganisms11112681 -
Genome Biology and Evolution Aug 2023Evolution experiments with free-living microbes have radically improved our understanding of genome evolution and how microorganisms adapt. Yet there is a paucity of...
Evolution experiments with free-living microbes have radically improved our understanding of genome evolution and how microorganisms adapt. Yet there is a paucity of such research focusing on strictly host-associated bacteria, even though they are widespread in nature. Here, we used the Acanthamoeba symbiont Protochlamydia amoebophila, a distant relative of the human pathogen Chlamydia trachomatis and representative of a large group of protist-associated environmental chlamydiae, as a model to study how obligate intracellular symbionts evolve and adapt to elevated temperature, a prerequisite for the pivotal evolutionary leap from protist to endothermic animal hosts. We established 12 replicate populations under two temperatures (20 °C, 30 °C) for 510 bacterial generations (38 months). We then used infectivity assays and pooled whole-genome resequencing to identify any evolved phenotypes and the molecular basis of adaptation in these bacteria. We observed an overall reduction in infectivity of the symbionts evolved at 30 °C, and we identified numerous nonsynonymous mutations and small indels in these symbiont populations, with several variants persisting throughout multiple time points and reaching high frequencies. This suggests that many mutations may have been beneficial and played an adaptive role. Mutated genes within the same temperature regime were more similar than those between temperature regimes. Our results provide insights into the molecular evolution of intracellular bacteria under the constraints of strict host dependance and highly structured populations and suggest that for chlamydial symbionts of protists, temperature adaptation was facilitated through attenuation of symbiont infectivity as a tradeoff to reduce host cell burden.
Topics: Animals; Humans; Temperature; Bacteria; Acanthamoeba; Chlamydia; Evolution, Molecular; Genome, Bacterial; Symbiosis
PubMed: 37515591
DOI: 10.1093/gbe/evad139 -
Nature Methods Dec 2023Fluorescence microscopy has become an indispensable tool for revealing the dynamic regulation of cells and organelles. However, stochastic noise inherently restricts...
Fluorescence microscopy has become an indispensable tool for revealing the dynamic regulation of cells and organelles. However, stochastic noise inherently restricts optical interrogation quality and exacerbates observation fidelity when balancing the joint demands of high frame rate, long-term recording and low phototoxicity. Here we propose DeepSeMi, a self-supervised-learning-based denoising framework capable of increasing signal-to-noise ratio by over 12 dB across various conditions. With the introduction of newly designed eccentric blind-spot convolution filters, DeepSeMi effectively denoises images with no loss of spatiotemporal resolution. In combination with confocal microscopy, DeepSeMi allows for recording organelle interactions in four colors at high frame rates across tens of thousands of frames, monitoring migrasomes and retractosomes over a half day, and imaging ultra-phototoxicity-sensitive Dictyostelium cells over thousands of frames. Through comprehensive validations across various samples and instruments, we prove DeepSeMi to be a versatile and biocompatible tool for breaking the shot-noise limit.
Topics: Dictyostelium; Image Enhancement; Microscopy, Confocal; Signal-To-Noise Ratio; Microscopy, Fluorescence; Image Processing, Computer-Assisted
PubMed: 37957429
DOI: 10.1038/s41592-023-02058-9 -
Translational Vision Science &... Sep 2023To investigate the combined anti-Acanthamoeba effects of nitric oxide (NO) donors and hypochlorite to maximize amoebicidal outcomes while minimizing damage to human...
PURPOSE
To investigate the combined anti-Acanthamoeba effects of nitric oxide (NO) donors and hypochlorite to maximize amoebicidal outcomes while minimizing damage to human corneal epithelial cells (HCECs).
METHODS
Acanthamoeba castellanii and primary cultured HCECs and keratocytes were treated with sodium hypochlorite (NaOCl), NO donors (sodium nitroprusside [SNP] and sodium nitrite [NaNO2]), or a combination of hypochlorite and NO donors. The viability of A. castellanii, HCECs, and keratocytes was assessed. Minimal inhibitory concentration (MIC) and fractional inhibitory concentration of NaOCl and NO donors were determined. The activation of mammalian targets of rapamycin (mTOR) and ERK and the expression of nitrite reductase and Nrf2 were assessed in HCECs using Western blot analysis. The cysticidal effects of combined NaOCl and NO donors were also evaluated.
RESULTS
A dose-dependent toxicity was observed in A. castellanii, HCECs, and keratocytes when treated with NaOCl and SNP. The range of tested NaNO2 concentrations showed no significant toxicity to HCECs; however, dose-dependent toxicity to A. castellanii was observed. The MIC of NaOCl against HCECs and A. castellanii was 8.0 mg/mL. The MIC of NaNO2 and SNP was 500 mM and 10 mM in both HCECs and A. castellanii, respectively. Weak attenuation of the mTOR and ERK phosphorylation was observed and Nrf2 expression decreased slightly after exposure of HCECs to 2.0 mg/mL NaOCl. For the combination treatment, NaOCl (0.125 mg/mL) was selected based on the safety of HCECs and the toxicity of A. castellanii. A more potent anti-Acanthamoeba effect and HCEC toxicity were observed when NaOCl was combined with SNP rather than NaNO2.
CONCLUSIONS
Combined NaOCl and NO donors had a stronger anti-Acanthamoeba effect compared to either drug alone.
TRANSLATIONAL RELEVANCE
This study demonstrates that the combined use of various drugs for the treatment of Acanthamoeba infection can enhance the anti-Acanthamoeba effect while minimizing the toxicity of the individual drug.
Topics: Humans; Animals; Acanthamoeba castellanii; Nitric Oxide Donors; Hypochlorous Acid; NF-E2-Related Factor 2; TOR Serine-Threonine Kinases; Mammals
PubMed: 37768280
DOI: 10.1167/tvst.12.9.23 -
Pathogens and Global Health Oct 2023This study examines the effects of three different drugs with metformin, acarbose and pioglitazone active ingredients used for antidiabetic purposes on cysts and...
This study examines the effects of three different drugs with metformin, acarbose and pioglitazone active ingredients used for antidiabetic purposes on cysts and trophozoites. Cultures of trophozoites and cysts were prepared to test the anti-amoebic activity of metformin, acarbose and pioglitazone. Cultures were then prepared for cyst and trophozoite forms and parasites were exposed to different concentrations (0.750 mg/mL, 0.375 mg/mL, 0.186 mg/mL and 0.093 mg/mL) of metformin, acarbose and pioglitazone. As a result of the study, the reproductive potential suppressive effects and conversion from trophozoite form to cyst form of all three substances on trophozoites and cysts were determined. Parasites were counted at 12, 24 and 48 hours in the cell counter after staining with trypan blue. In comparison of the effects of metformin, acarbose and pioglitazone used in the study on trophozoites and cysts, it was observed that all three substances were statistically effective against cysts and trophozoites at a concentration of 0.750 mg/mL. Furthermore, it was determined that all concentrations of the three active substances included in the study significantly decreased the rate of cyst formation even at the end of the 7th day. In this context, it was determined that all three substances have amebicidal effects, and they significantly inhibit the transformation of trophozoites to cyst form. It is thought that these active substances, which are currently used as anti-diabetic, can be used in combination with other drugs in infections based on our study findings.
Topics: Animals; Trophozoites; Acanthamoeba castellanii; Hypoglycemic Agents; Acarbose; Pioglitazone; Metformin
PubMed: 36436006
DOI: 10.1080/20477724.2022.2151859 -
Turkiye Parazitolojii Dergisi Dec 2023The aim of this study is to determine the prevalence of intestinal parasites in patients admitted to University of Health Sciences Türkiye (UHS) Van Training and...
OBJECTIVE
The aim of this study is to determine the prevalence of intestinal parasites in patients admitted to University of Health Sciences Türkiye (UHS) Van Training and Research Hospital.
METHODS
A total of 300 patients between the ages of 18-90 who applied to UHS Van Training and Research Hospital with gastrointestinal complaints and were referred to the parasitology laboratory between September 2021 and December 2021, and 100 patients without any chronic disease and gastrointestinal complaints in the control group were included in the study. Stool samples taken from patients included in the study and individuals in the control group were analyzed by native-lugol and modified acid-fast staining methods.
RESULTS
In the study, intestinal parasites were detected in 41 (13.3%) of 300 patients in the patient group and in seven (7%) of 100 individuals in the control group. The highest rate of species ( spp.) (5.7%) was found in the patient group. 3%, 2.7% and species ( spp). 2.3% were found among the other species detected. In addition, a statistically significant correlation was found between the incidence of parasites and abdominal pain (p=0.022) and nausea (p=0.029).
CONCLUSION
As a result; it was concluded that intestinal parasites are still an important health problem in patients with gastrointestinal complaints and intestinal parasites should definitely be considered in this patient group.
Topics: Animals; Humans; Adolescent; Young Adult; Adult; Middle Aged; Aged; Aged, 80 and over; Parasites; Cryptosporidiosis; Cryptosporidium; Feces; Intestinal Diseases, Parasitic; Blastocystis; Prevalence
PubMed: 38149443
DOI: 10.4274/tpd.galenos.2023.93585