-
Cell Host & Microbe Jul 2023The colon mucus layer is organized with an inner colon mucus layer that is impenetrable to bacteria and an outer mucus layer that is expanded to allow microbiota... (Review)
Review
The colon mucus layer is organized with an inner colon mucus layer that is impenetrable to bacteria and an outer mucus layer that is expanded to allow microbiota colonization. A major component of mucus is MUC2, a glycoprotein that is extensively decorated, especially with O-glycans. In the intestine, goblet cells are specialized in controlling glycosylation and making mucus. Some microbiota members are known to encode multiple proteins that are predicted to bind and/or cleave mucin glycans. The interactions between commensal microbiota and host mucins drive intestinal colonization, while at the same time, the microbiota can utilize the glycans on mucins and affect the colonic mucus properties. This review will examine this interaction between commensal microbes and intestinal mucins and discuss how this interplay affects health and disease.
Topics: Intestinal Mucosa; Mucin-2; Intestines; Mucus; Mucins; Microbiota; Polysaccharides
PubMed: 37442097
DOI: 10.1016/j.chom.2023.05.026 -
JAMA Jun 2023Airway mucus plugs are common in patients with chronic obstructive pulmonary disease (COPD); however, the association of airway mucus plugging and mortality in patients... (Observational Study)
Observational Study
IMPORTANCE
Airway mucus plugs are common in patients with chronic obstructive pulmonary disease (COPD); however, the association of airway mucus plugging and mortality in patients with COPD is unknown.
OBJECTIVE
To determine whether airway mucus plugs identified on chest computed tomography (CT) were associated with increased all-cause mortality.
DESIGN, SETTING, AND PARTICIPANTS
Observational retrospective analysis of prospectively collected data of patients with a diagnosis of COPD in the Genetic Epidemiology of COPD cohort. Participants were non-Hispanic Black or White individuals, aged 45 to 80 years, who smoked at least 10 pack-years. Participants were enrolled at 21 centers across the US between November 2007 and April 2011 and were followed up through August 31, 2022.
EXPOSURES
Mucus plugs that completely occluded airways on chest CT scans, identified in medium- to large-sized airways (ie, approximately 2- to 10-mm lumen diameter) and categorized as affecting 0, 1 to 2, or 3 or more lung segments.
MAIN OUTCOMES AND MEASURES
The primary outcome was all-cause mortality, assessed with proportional hazard regression analysis. Models were adjusted for age, sex, race and ethnicity, body mass index, pack-years smoked, current smoking status, forced expiratory volume in the first second of expiration, and CT measures of emphysema and airway disease.
RESULTS
Among the 4483 participants with COPD, 4363 were included in the primary analysis (median age, 63 years [IQR, 57-70 years]; 44% were women). A total of 2585 (59.3%), 953 (21.8%), and 825 (18.9%) participants had mucus plugs in 0, 1 to 2, and 3 or more lung segments, respectively. During a median 9.5-year follow-up, 1769 participants (40.6%) died. The mortality rates were 34.0% (95% CI, 32.2%-35.8%), 46.7% (95% CI, 43.5%-49.9%), and 54.1% (95% CI, 50.7%-57.4%) in participants who had mucus plugs in 0, 1 to 2, and 3 or more lung segments, respectively. The presence of mucus plugs in 1 to 2 vs 0 and 3 or more vs 0 lung segments was associated with an adjusted hazard ratio of death of 1.15 (95% CI, 1.02-1.29) and 1.24 (95% CI, 1.10-1.41), respectively.
CONCLUSIONS AND RELEVANCE
In participants with COPD, the presence of mucus plugs that obstructed medium- to large-sized airways was associated with higher all-cause mortality compared with patients without mucus plugging on chest CT scans.
Topics: Female; Humans; Male; Middle Aged; Airway Obstruction; Forced Expiratory Volume; Lung; Mucus; Pulmonary Disease, Chronic Obstructive; Pulmonary Emphysema; Retrospective Studies; Tomography, X-Ray Computed; Aged; Aged, 80 and over; Cigarette Smoking
PubMed: 37210745
DOI: 10.1001/jama.2023.2065 -
Virulence Dec 2023The amoeba parasite is the causative agent of human amebiasis, an enteropathic disease affecting millions of people worldwide. This ancient protozoan is an elementary... (Review)
Review
The amoeba parasite is the causative agent of human amebiasis, an enteropathic disease affecting millions of people worldwide. This ancient protozoan is an elementary example of how parasites evolve with humans, e.g. taking advantage of multiple mechanisms to evade immune responses, interacting with microbiota for nutritional and protective needs, utilizing host resources for growth, division, and encystation. These skills of perpetuate the species and incidence of infection. However, in 10% of infected cases, the parasite turns into a pathogen; the host-parasite equilibrium is then disorganized, and the simple lifecycle based on two cell forms, trophozoites and cysts, becomes unbalanced. Trophozoites acquire a virulent phenotype which, when non-controlled, leads to intestinal invasion with the onset of amoebiasis symptoms. Virulent must cross mucus, epithelium, connective tissue and possibly blood. This highly mobile parasite faces various stresses and a powerful host immune response, with oxidative stress being a challenge for its survival. New emerging research avenues and omics technologies target gene regulation to determine human or parasitic factors activated upon infection, their role in virulence activation, and in pathogenesis; this research bears in mind that is a resident of the complex intestinal ecosystem. The goal is to eradicate amoebiasis from the planet, but the parasitic life of is ancient and complex and will likely continue to evolve with humans. Advances in these topics are summarized here.
Topics: Humans; Entamoeba histolytica; Virulence; Ecosystem; Amebiasis; Intestines
PubMed: 36519347
DOI: 10.1080/21505594.2022.2158656