The Pulmonary Extracellular Matrix Is a Bactericidal Barrier Against Haemophilus influenzae in Chronic Obstructive Pulmonary Disease (COPD): Implications for an in vivo Innate Host Defense Function of Collagen VI

Investigation of the Presence of Fibrillin in Sea Cucumber (Apostichopus japonicus) Body Wall by Utilizing Targeted Proteomics and Visualization Strategies

Fibrillin is an important structural protein in connective tissues. The presence of fibrillin in sea cucumber Apostichopus japonicus is still poorly understood, which limits our understanding of the role of fibrillin in the A. japonicus microstructure. The aim of this study was to clarify the presence of fibrillin in the sea cucumber A. japonicus body wall. Herein, the presence of fibrillin in sea cucumber A. japonicus was investigated by utilizing targeted proteomics and visualization strategies. The contents of three different isoforms of fibrillin with high abundance in A. japonicus were determined to be 0.96, 2.54, and 0.15 μg/g (wet base), respectively. The amino acid sequence of fibrillin (GeneBank number: PIK56741.1) that started at position 631 and ended at position 921 was selected for cloning and expressing antigen. An anti-A. japonicus fibrillin antibody with a titer greater than 1:64 000 was successfully obtained. It was observed that the distribution of fibrillin in the A. japonicus body wall was scattered and dispersed in the form of fibril bundles at the microscale. It further observed that fibrillin was present near collagen fibrils and some entangled outside the collagen fibrils at the nanoscale. Moreover, the stoichiometry of the most dominant collagen and fibrillin molecules in A. japonicus was determined to be approximately 250:1. These results contribute to an understanding of the role of fibrillin in the sea cucumber microstructure.

Focal adhesion signaling pathway involved in skin immune response of tongue sole Cynoglossus semilaevis to Vibrio vulnificus infection

Focal adhesion (FA) plays a key role in cell adhesion, migration and antibacterial immune, but it remained unclear in fish. In this study, half-smooth tongue sole Cynoglossus semilaevis were infected with Vibrio vulnificus, and then immune-related protein in the skin, especially for FA signaling pathway were screened and identified by iTRAQ analysis. Results showed that the differentially expressed proteins (DEPs) in skin immune response (eg., ITGA6, FN, COCH, AMBP, COL6A1, COL6A3, COL6A6, LAMB1, LAMC1, FLMNA) were firstly found in FA signaling pathway. Furthermore, the validation analysis of FA-related genes were basically consistent with the iTRAQ data at 36 hpi (r = 0.678, p < 0.01), and their spatio-temporal expressions were confirmed by qPCR analysis. The molecular characterization of vinculin of C. semilaevis was described. This study will provide a new perspective for understanding the molecular mechanism of FA signaling pathway in the skin immune response in marine fish.

Basement membranes in obstructive pulmonary diseases

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Basement membrane composition is changed in the airways of patients with obstructive airway diseases.

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Basement membrane changes are linked to disease characteristics in patients.

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Mechanisms behind the altered BM composition remain to be elucidated.

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Laminin and collagen IV affect key pathological processes in obstructive airway diseases.

Increased and changed deposition of extracellular matrix proteins is a key feature of airway wall remodeling in obstructive pulmonary diseases, including asthma and chronic obstructive pulmonary disease. Studies have highlighted that the deposition of various basement membrane proteins in the lung tissue is altered and that these changes reflect tissue compartment specificity. Inflammatory responses in both diseases may result in the deregulation of production and degradation of these proteins. In addition to their role in tissue development and integrity, emerging evidence indicates that basement membrane proteins also actively modulate cellular processes in obstructive airway diseases, contributing to disease development, progression and maintenance. In this review, we summarize the changes in basement membrane composition in airway remodeling in obstructive airway diseases and explore their potential application as innovative targets for treatment development.

Methylome-wide Analysis Reveals Epigenetic Marks Associated With Resistance to Tuberculosis in Human Immunodeficiency Virus-Infected Individuals From East Africa

BACKGROUND

Tuberculosis (TB) is the most deadly infectious disease globally and is highly prevalent in the developing world. For individuals infected with both Mycobacterium tuberculosis (Mtb) and human immunodeficiency virus (HIV), the risk of active TB is 10% or more annually. Previously, we identified in a genome-wide association study (GWAS) a region on chromosome 5 associated with resistance to TB, which included epigenetic marks that could influence gene regulation. We hypothesized that HIV-infected individuals exposed to Mtb who remain disease free carry epigenetic changes that strongly protect them from active TB.

METHODS

We conducted a methylome-wide study in HIV-infected, TB-exposed cohorts from Uganda and Tanzania and integrated data from our GWAS.

RESULTS

We identified 3 regions of interest that included markers that were differentially methylated between TB cases and controls with latent TB infection: chromosome 1 (RNF220, P = 4 × 10-5), chromosome 2 (between COPS8 and COL6A3, P = 2.7 × 10-5), and chromosome 5 (CEP72, P = 1.3 × 10-5). These methylation results co-localized with associated single-nucleotide polymorphisms (SNPs), methylation QTLs, and methylation × SNP interaction effects. These markers were in regions with regulatory markers for cells involved in TB immunity and/or lung.

CONCLUSIONS

Epigenetic regulation is a potential biologic factor underlying resistance to TB in immunocompromised individuals that can act in conjunction with genetic variants.

Protein Signatures of Remodeled Airways in Transplanted Lungs with Bronchiolitis Obliterans Syndrome Obtained Using Laser-Capture Microdissection

Bronchiolitis obliterans syndrome, a common form of chronic lung allograft dysfunction, is the major limitation to long-term survival after lung transplantation. The histologic correlate is progressive, fibrotic occlusion of small airways, obliterative bronchiolitis lesions, which ultimately lead to organ failure. The molecular composition of these lesions is unknown. In this sutdy, the protein composition of the lesions in explanted lungs from four end-stage bronchiolitis obliterans syndrome patients was analyzed using laser-capture microdissection and optimized sample preparation protocols for mass spectrometry. Immunohistochemistry and immunofluorescence were used to determine the spatial distribution of commonly identified proteins on the tissue level, and protein signatures for 14 obliterative bronchiolitis lesions were established. A set of 39 proteins, identified in >75% of lesions, included distinct structural proteins (collagen types IV and VI) and cellular components (actins, vimentin, and tryptase). Each respective lesion exhibited a unique composition of proteins (on average, n = 66 proteins), thereby mirroring the morphologic variation of the lesions. Antibody-based staining confirmed these mass spectrometry-based findings. The 14 analyzed obliterative bronchiolitis lesions showed variations in their protein content, but also common features. This study provides molecular and morphologic insights into the development of chronic rejection after lung transplantation. The protein patterns in the lesions were correlated to pathways of extracellular matrix organization, tissue development, and wound healing processes.

AChR antibodies show a complex interaction with human skeletal muscle cells in a transcriptomic study

Acetylcholine receptor (AChR) antibodies are the most important pathogenic marker in patients with myasthenia gravis (MG). The antibodies bind to AChRs on the postsynaptic membrane, and this leads to receptor degradation, destruction, or functional blocking with impaired signal at the neuromuscular junction. In this study, we have explored the effects of AChR antibodies binding to mature human myotubes with agrin-induced AChR clusters and pathways relevant for AChR degradation using bulk RNA sequencing. Protein-coding RNAs and lncRNAs were examined by RNA sequencing analysis. AChR antibodies induced marked changes of the transcriptomic profiles, with over 400 genes differentially expressed. Cholesterol metabolic processes and extracellular matrix organization gene sets were influenced and represent AChR-trafficking related pathways. Muscle contraction and cellular homeostasis gene sets were also affected, and independently of AChR trafficking. Furthermore, we found changes in a protein-coding RNA and lncRNA network, where expression of lncRNA MEG3 correlated closely with protein-coding genes for cellular homeostasis. We conclude that AChR antibodies induce an active response in human skeletal muscle cells which affects key intra- and extracellular pathways.