scholarly journals Insights into Oropharyngeal Microbiota, Biofilms and Associated Diseases from Metagenomics and Transcriptomic Approaches

2021 ◽  
Author(s):  
Richa Priyadarshini ◽  
Karthik Krishnan ◽  
Rashmi Niranjan

Oral cavity is an ecologically complex environment and hosts a diverse microbial community. Most of these organisms are commensals, however, on occasion, some have the potential to become pathogenic causing damage to the human host. Complex interactions between pathogenic bacteria, the microbiota, and the host can modify pathogen physiology and behavior. Most bacteria in the environment do not exist in free-living state but are found as complex matrix enclosed aggregates known as biofilms. There has been research interest in microbial biofilms because of their importance in industrial and biomedical settings. Bacteria respond to environmental cues to fine-tune the transition from planktonic growth to biofilm by directing gene expression changes favorable for sessile community establishment. Meta-approaches have been used to identify complex microbial associations within human oral cavity leading to important insights. Comparative gene expression analysis using deep sequencing of RNA and metagenomics studies done under varying conditions have been successfully used in understanding and identifying possible triggers of pathogenicity and biofilm formation in oral commensals.

2018 ◽  
Author(s):  
Daisuke Kyoui ◽  
Hiroyuki Yamamoto ◽  
Natsumi Mikami ◽  
Ryota Ishii ◽  
Hiroki Tanaka ◽  
...  

DNA sequencing technology has been improved drastically in the recent decades, which allows comprehensively analyze microbial community and gene expression. Simultaneously with the improvements, many tools and software for much amount of sequence data have been released. These analysis tools/software can produce statistic information. However, to interpret and to find the relationships and/or associations between the information and the experimental condition may be a complex task, especially for non-bioinformaticians. In this article, an open source software TOMVi (Tool for Overviewing Metadata Visualization) which visualized similarity and relationships between the samples corresponding to the experimental conditions was introduced. TOMVi allows researcher to interactively manipulate the composition data in each sample toward to each experimental condition such as location, time-series and others with graphical user interface (GUI), and to visualize the existence and behavior of each OTU. The figure illustrated by this tool can provide an intuitive suggestion but not always correct as statistically, and will be helpful to decide further analyzing tactics. The TOMVi is available at http://github.com/Daisuke-Kyoui/tomvi.


2016 ◽  
Vol 371 (1707) ◽  
pp. 20150504 ◽  
Author(s):  
Nathalie Rolhion ◽  
Benoit Chassaing

The intestinal microbiota is a large and diverse microbial community that inhabits the intestinal tract, containing about 100 trillion bacteria from 500–1000 distinct species that, collectively, provide multiple benefits to the host. The gut microbiota contributes to nutrient absorption and maturation of the immune system, and also plays a central role in protection of the host from enteric bacterial infection. On the other hand, many enteric pathogens have developed strategies in order to be able to outcompete the intestinal community, leading to infection and/or chronic diseases. This review will summarize findings describing the complex relationship occurring between the intestinal microbiota and enteric pathogens, as well as how future therapies can ultimately benefit from such discoveries. This article is part of the themed issue ‘The new bacteriology’.


2021 ◽  
Vol 22 (21) ◽  
pp. 11312
Author(s):  
Dariusz Żurawek ◽  
Gustavo Turecki

Depression is an effect of complex interactions between genetic, epigenetic and environmental factors. It is well established that stress responses are associated with multiple modest and often dynamic molecular changes in the homeostatic balance, rather than with a single genetic factor that has a strong phenotypic penetration. As depression is a multifaceted phenotype, it is important to study biochemical pathways that can regulate the overall allostasis of the brain. One such biological system that has the potential to fine-tune a multitude of diverse molecular processes is RNA interference (RNAi). RNAi is an epigenetic process showing a very low level of evolutionary diversity, and relies on the posttranscriptional regulation of gene expression using, in the case of mammals, primarily short (17–23 nucleotides) noncoding RNA transcripts called microRNAs (miRNA). In this review, our objective was to examine, summarize and discuss recent advances in the field of biomedical and clinical research on the role of miRNA-mediated regulation of gene expression in the development of depression. We focused on studies investigating post-mortem brain tissue of individuals with depression, as well as research aiming to elucidate the biomarker potential of miRNAs in depression and antidepressant response.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Cécile Gaston ◽  
Simon De Beco ◽  
Bryant Doss ◽  
Meng Pan ◽  
Estelle Gauquelin ◽  
...  

AbstractAt the basis of cell shape and behavior, the organization of actomyosin and its ability to generate forces are widely studied. However, the precise regulation of this contractile network in space and time is unclear. Here, we study the role of the epithelial-specific protein EpCAM, a contractility modulator, in cell shape and motility. We show that EpCAM is required for stress fiber generation and front-rear polarity acquisition at the single cell level. In fact, EpCAM participates in the remodeling of a transient zone of active RhoA at the cortex of spreading epithelial cells. EpCAM and RhoA route together through the Rab35/EHD1 fast recycling pathway. This endosomal pathway spatially organizes GTP-RhoA to fine tune the activity of actomyosin resulting in polarized cell shape and development of intracellular stiffness and traction forces. Impairment of GTP-RhoA endosomal trafficking either by silencing EpCAM or by expressing Rab35/EHD1 mutants prevents proper myosin-II activity, stress fiber formation and ultimately cell polarization. Collectively, this work shows that the coupling between co-trafficking of EpCAM and RhoA, and actomyosin rearrangement is pivotal for cell spreading, and advances our understanding of how biochemical and mechanical properties promote cell plasticity.


Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 326
Author(s):  
Yu-Jun Wang ◽  
Hua-Ling Wang ◽  
Xiao-Wei Wang ◽  
Shu-Sheng Liu

Females and males often differ obviously in morphology and behavior, and the differences between sexes are the result of natural selection and/or sexual selection. To a great extent, the differences between the two sexes are the result of differential gene expression. In haplodiploid insects, this phenomenon is obvious, since males develop from unfertilized zygotes and females develop from fertilized zygotes. Whiteflies of the Bemisia tabaci species complex are typical haplodiploid insects, and some species of this complex are important pests of many crops worldwide. Here, we report the transcriptome profiles of males and females in three species of this whitefly complex. Between-species comparisons revealed that non-sex-biased genes display higher variation than male-biased or female-biased genes. Sex-biased genes evolve at a slow rate in protein coding sequences and gene expression and have a pattern of evolution that differs from those of social haplodiploid insects and diploid animals. Genes with high evolutionary rates are more related to non-sex-biased traits—such as nutrition, immune system, and detoxification—than to sex-biased traits, indicating that the evolution of protein coding sequences and gene expression has been mainly driven by non-sex-biased traits.


2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Constance Schmelzer ◽  
Mitsuaki Kitano ◽  
Gerald Rimbach ◽  
Petra Niklowitz ◽  
Thomas Menke ◽  
...  

MicroRNAs (miRs) are involved in key biological processes via suppression of gene expression at posttranscriptional levels. According to their superior functions, subtle modulation of miR expression by certain compounds or nutrients is desirable under particular conditions. Bacterial lipopolysaccharide (LPS) induces a reactive oxygen species-/NF-κB-dependent pathway which increases the expression of the anti-inflammatory miR-146a. We hypothesized that this induction could be modulated by the antioxidant ubiquinol-10. Preincubation of human monocytic THP-1 cells with ubiquinol-10 reduced the LPS-induced expression level of miR-146a to 78.9±13.22%. In liver samples of mice injected with LPS, supplementation with ubiquinol-10 leads to a reduction of LPS-induced miR-146a expression to 78.12±21.25%. From these consistent in vitro and in vivo data, we conclude that ubiquinol-10 may fine-tune the inflammatory response via moderate reduction of miR-146a expression.


2016 ◽  
Vol 73 (1) ◽  
pp. 94-104 ◽  
Author(s):  
Elsa Goerig ◽  
Theodore Castro-Santos ◽  
Normand Émile Bergeron

Culverts can restrict access to habitat for stream-dwelling fishes. We used passive integrated transponder telemetry to quantify passage performance of >1000 wild brook trout (Salvelinus fontinalis) attempting to pass 13 culverts in Quebec under a range of hydraulic and environmental conditions. Several variables influenced passage success, including complex interactions between physiology and behavior, hydraulics, and structural characteristics. The probability of successful passage was greater through corrugated metal culverts than through smooth ones, particularly among smaller fish. Trout were also more likely to pass at warmer temperatures, but this effect diminished above 15 °C. Passage was impeded at higher flows, through culverts with steep slopes, and those with deep downstream pools. This study provides insight on factors influencing brook trout capacity to pass culverts as well as a model to estimate passage success under various conditions, with an improved resolution and accuracy over existing approaches. It also presents methods that could be used to investigate passage success of other species, with implications for connectivity of the riverscape.


Genetics ◽  
2021 ◽  
Vol 217 (1) ◽  
Author(s):  
Amir Fallahshahroudi ◽  
Martin Johnsson ◽  
Enrico Sorato ◽  
S J Kumari A Ubhayasekera ◽  
Jonas Bergquist ◽  
...  

Abstract Domestic chickens are less fearful, have a faster sexual development, grow bigger, and lay more eggs than their primary ancestor, the red junglefowl. Several candidate genetic variants selected during domestication have been identified, but only a few studies have directly linked them with distinct phenotypic traits. Notably, a variant of the thyroid stimulating hormone receptor (TSHR) gene has been under strong positive selection over the past millennium, but it’s function and mechanisms of action are still largely unresolved. We therefore assessed the abundance of the domestic TSHR variant and possible genomic selection signatures in an extensive data set comprising multiple commercial and village chicken populations as well as wild-living extant members of the genus Gallus. Furthermore, by mean of extensive backcrossing we introgressed the wild-type TSHR variant from red junglefowl into domestic White Leghorn chickens and investigated gene expression, hormone levels, cold adaptation, and behavior in chickens possessing either the wild-type or domestic TSHR variant. While the domestic TSHR was the most common variant in all studied domestic populations and in one of two red junglefowl population, it was not detected in the other Gallus species. Functionally, the individuals with the domestic TSHR variant had a lower expression of the TSHR in the hypothalamus and marginally higher in the thyroid gland than wild-type TSHR individuals. Expression of TSHB and DIO2, two regulators of sexual maturity and reproduction in birds, was higher in the pituitary gland of the domestic-variant chickens. Furthermore, the domestic variant was associated with higher activity in the open field test. Our findings confirm that the spread of the domestic TSHR variant is limited to domesticated chickens, and to a lesser extent, their wild counterpart, the red junglefowl. Furthermore, we showed that effects of genetic variability in TSHR mirror key differences in gene expression and behavior previously described between the red junglefowl and domestic chicken.


2007 ◽  
Vol 189 (7) ◽  
pp. 2629-2636 ◽  
Author(s):  
Hyun-Jung Lee ◽  
So Hyun Bang ◽  
Kyu-Ho Lee ◽  
Soon-Jung Park

ABSTRACT In pathogenic bacteria, the ability to acquire iron, which is mainly regulated by the ferric uptake regulator (Fur), is essential to maintain growth as well as its virulence. In Vibrio vulnificus, a human pathogen causing gastroenteritis and septicemia, fur gene expression is positively regulated by Fur when the iron concentration is limited (H.-J. Lee et al., J. Bacteriol. 185:5891-5896, 2003). Footprinting analysis revealed that an upstream region of the fur gene was protected by the Fur protein from DNase I under iron-depleted conditions. The protected region, from −142 to −106 relative to the transcription start site of the fur gene, contains distinct AT-rich repeats. Mutagenesis of this repeated sequence resulted in abolishment of binding by Fur. To confirm the role of this cis-acting element in Fur-mediated control of its own gene in vivo, fur expression was monitored in V. vulnificus strains using a transcriptional fusion containing the mutagenized Fur-binding site (fur mt::luxAB). Expression of fur mt::luxAB showed that it was not regulated by Fur and was not influenced by iron concentration. Therefore, this study demonstrates that V. vulnificus Fur acts as a positive regulator under iron-limited conditions by direct interaction with the fur upstream region.


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