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There is growing recognition that mucus and mucin biology have a considerable impact on respiratory health, and subsequent global morbidity and mortality. Mucins play a critical role in chronic lung disease, not only by providing a physical barrier and clearing pathogens, but also in immune homeostasis. The aim of this review is to familiarise the reader with the role of mucins in both lung health and disease, with particular focus on function in immunity, infection and inflammation. We will also discuss their receptors, termed glycan‐binding proteins, and how they provide an attractive prospect for therapeutic intervention., This review article explores the role of mucins in respiratory health and disease, with particular focus on their receptors, the glycan‐binding proteins.

The aim of the present study was to investigate the effects of fatty fish consumption on cognitive functioning in a group of inpatients characterized by antisocial behavior. Eighty-three male forensic inpatients participated in this study. Participants were randomly assigned into a Fish or a Control group (e.g., meat, chicken, pork). One decision-making task, the Iowa Gambling Task (IGT), and one planning task, the Tower of Hanoi (ToH), were administered before (pre-test) and at the end of the intervention period (post-test). For the IGT the Fish group showed improved performance from pre- to post- test. Moreover, the Fish group showed significantly better performance than the Control group on the IGT at post-test. The Fish group also demonstrated improved performance from pre- to post-test on the ToH; however, this was limited to participants with a history of substance abuse. Further, the improvement was only significant for tasks with high working memory load (5-7 move problems), and not for tasks with low working memory load (1-4 move problems). The Control group showed no improvement on any of the tasks regardless of alcohol or drug abuse history. The present study suggests that regular fatty fish consumption may improve executive functions in forensic inpatients with antisocial traits and a history of substance abuse. Thus, the current results may have important implications with regard to health care interventions.

The chondrodysplasias are a group of >450 different phenotypes (1) that occur when endochondral bone growth is disrupted (2). The clinical presentation of chondrodysplasia varies from mild to lethal but is generally distinguished by disproportionate short stature. Multiple epiphyseal dysplasia (MED) is characterized by delayed and irregular endochondral ossification and early-onset osteoarthritis (3, 4). MED is genetically heterogeneous, and autosomal-dominant forms of the disease arise from mutations in the genes encoding matrilin 3, cartilage oligomeric matrix protein (COMP), and type IX collagen (3–5). Although present in other musculoskeletal tissues, matrilin 3, COMP, and type IX collagen are expressed primarily by chondrocytes and have been shown to interact with each other, both in vitro and in vivo (6–13). The matrilins are a family of 4 noncollagenous extracellular matrix (ECM) proteins. Each matrilin monomer comprises a C-terminal α-helical coiled-coil oligomerization domain, a varying number of epidermal growth factor–like domains, and 1 (matrilin 3) or 2 (matrilins 1, 2, and 4) von Willebrand factor A domains (6, 14). Matrilin proteins bind to numerous ECM components, including type II collagen, type IX collagen, aggrecan, COMP, biglycan, and decorin, and are believed to act as adaptor proteins in the ECM (6). More than 20 different missense mutations within the matrilin 3 gene have been shown to cause autosomal-dominant MED, and MATN3 mutations are believed to account for ∼20% of all cases of autosomal-dominant MED (5). The majority of MATN3 mutations affect residues that are located within the central β-sheet of the single A domain of matrilin 3 (5, 15–17), while a smaller proportion of mutations that affect residues in the α-helices of the same domain have recently been described (5, 18, 19). Several different cell culture model systems have been used in the past to study the effect of matrilin 3 mutations in vitro (15, 19, 20). The most striking effect of MATN3 mutations was the intracellular retention of mutant protein in cells in culture and also in patient cartilage. This distinctive finding was recently verified in a murine model of MED caused by a Matn3 V194D mutation, which replicated the human phenotype by exhibiting mild short-limbed dwarfism (21, 22). In this murine model, mutant matrilin 3 was retained within the endoplasmic reticulum (ER) of chondrocytes from the growth plates of endochondral bones. The retention of mutant matrilin 3 elicited a conventional unfolded protein response characterized by the up-regulation of classic chaperone proteins such as BiP/glucose-regulated protein 78-kd, calnexin, and calreticulin, as well as less-characterized ER stress–associated genes such as Creld2 and Armet/Manf (22). Despite intracellular retention of the majority of mutant matrilin 3 in vivo, a small proportion of mutant protein was secreted into the ECM, even in mice that were homozygous for the V194D mutation (21). The structural and/or functional effect of this mutant matrilin 3 in the ECM is not known, nor is the extent to which its presence in the ECM might contribute to the chondrodysplasia phenotype. Given the widespread literature describing the hetero-oligomerization of matrilin 3 with matrilin 1 (23–26), we considered the possibility that the secretion of mutant matrilin 3 may be dependent on its oligomerization into heterotetramers containing wild-type matrilin 1. We hypothesized that deletion of matrilin 1, which would abolish the formation of matrilin 1/matrilin 3 heterotetramers, would also eliminate the secretion of mutant matrilin 3 into the ECM and increase the severity of chondrodysplasia in mice with the Matn3 V194D mutation. A study testing this hypothesis would provide new insight into the disease mechanisms of MED and the role of hetero-oligomerization on the trafficking and secretion of matrilin 1/matrilin 3 proteins. We therefore crossed mice with the Matn3 V194D (Matn3m/m) mutation with Matn1−/− mice and generated a novel mouse line that was homozygous for the Matn3 V194D mutation and null for matrilin 1 (Matn1−/−Matn3m/m). We investigated the phenotypic, morphologic, and biochemical characterization of this novel murine model to determine the interdependency of matrilin 1 and matrilin 3 oligomerization on the trafficking and secretion of these proteins and their effect on disease severity.

The intestinal mucosal barrier, part of the innate immune defence, is responsive to the external environment and changes in response to infection. There is disparate evidence for the epithelial and goblet cell products within the intrinsic barrier being part of a response to resolve infection. We comprehensively analysed the changes of mucosal glycoconjugates during acute and chronic infection by utilising the Trichuris muris (T. muris) model. Transcription factors, atonal homolog 1 (Math-1) and SAM pointed domain containing ETS transcription factor (Spdef) were activated during acute infection, which promoted stem cell fate towards a secretory cell phenotype. The thickness of the intermediate barrier, the carbohydrate-rich glycocalyx, composed of cell surface mucins increased with exposure to T. muris, with an increase in Muc4, Muc13 and Muc17. Overall, hypersecretion of glycoproteins into the extrinsic barrier (mediated by IL-13) via the gamma amino-butyric acid-α3 receptor (GABA-α3), was observed during acute infection. Furthermore, altered glycosylation was observed during acute and chronic infection; mucins were more highly charged during acute infection than during chronic infection. This study readdresses the changes within the mucosal barrier, in particular in the cell surface and secreted mucins during acute and chronic nematode infection.

Cartilage is a highly specialized load-bearing tissue with a small number of cells and a high proportion of extracellular matrix (ECM). The abundance of heavily sulfated proteoglycans and a poorly soluble collagenous ECM presents a major technical challenge to 2-DE. Here we report proteomic analysis of mouse growth plate cartilage using novel methodology for tissue dissection and sample prefractionation. We have successfully resolved cartilage tissue extracts by 2-DE for the first time and identified cartilage ECM proteins by Western blotting and MS/MS.