Project description:Protein disulfide isomerases (PDIs) aid protein folding and assembly by catalyzing formation and shuffling of cysteine disulfide bonds in the endoplasmic reticulum (ER). Many members of the PDI family are expressed in mammals but the roles of specific PDIs in vivo are poorly understood. A recent homology-based search for additional PDI family members identified anterior gradient homolog 2 (AGR2), a protein originally presumed to be secreted by intestinal epithelial cells, but the function of AGR2 has been obscure. Here we show that AGR2 is expressed in the ER of secretory cells and is essential for in vivo production of intestinal mucin, a large cysteine-rich glycoprotein that forms the protective mucus gel lining the intestine. A cysteine residue within the AGR2 thioredoxin-like domain forms mixed disulfide bonds with MUC2, consistent with a direct role for AGR2 in mucin processing. Despite a complete absence of intestinal mucin, mice lacking AGR2 appeared healthy but were highly susceptible to dextran sodium sulfate-induced experimental colitis, indicating a critical role for AGR2 in protection from environmental insults. We conclude that AGR2 is a unique member of the PDI family that has a specialized and non-redundant role in intestinal mucus production. Keywords: small intestine and colon gene expression profiles for Agr2-/- and littermate control mice
Project description:Protein disulfide isomerases (PDIs) aid protein folding and assembly by catalyzing formation and shuffling of cysteine disulfide bonds in the endoplasmic reticulum (ER). Many members of the PDI family are expressed in mammals but the roles of specific PDIs in vivo are poorly understood. A recent homology-based search for additional PDI family members identified anterior gradient homolog 2 (AGR2), a protein originally presumed to be secreted by intestinal epithelial cells, but the function of AGR2 has been obscure. Here we show that AGR2 is expressed in the ER of secretory cells and is essential for in vivo production of intestinal mucin, a large cysteine-rich glycoprotein that forms the protective mucus gel lining the intestine. A cysteine residue within the AGR2 thioredoxin-like domain forms mixed disulfide bonds with MUC2, consistent with a direct role for AGR2 in mucin processing. Despite a complete absence of intestinal mucin, mice lacking AGR2 appeared healthy but were highly susceptible to dextran sodium sulfate-induced experimental colitis, indicating a critical role for AGR2 in protection from environmental insults. We conclude that AGR2 is a unique member of the PDI family that has a specialized and non-redundant role in intestinal mucus production. Keywords: small intestine and colon gene expression profiles for Agr2-/- and littermate control mice DNA miocroarrays were used to analyze small intenstine and colon mRNA expression of AGR2 KO and littermate control mice. The experiment incorporated a 1 color design and used Agilent arrays that contained roughly 44,00 60mer probes that provide complete coverage of the mouse genome. 12 arrays were hybridized and represent 8 small intestine samples ( 4 each KO and WT) and 4 colon samples (2 each KO and WT)
Project description:This study tested the hypothesis that a medicinal plant, Vasaka, typically consumed as a tea to treat respiratory malaise, could protect airway epithelial cells (AECs) from wood smoke particle-induced damage and prevent pathological mucus expression. Wood/biomass smoke is a common pneumotoxic air pollutant that activates transient receptor potential ankyrin 1 (TRPA1) and causes endoplasmic reticulum (ER) stress and AEC damage. This stimulates epidermal growth factor receptor and mucin 5AC (MUC5AC) production by AECs. Mucus normally protects the airways, but excessive MUC5AC production can obstruct airflow and cause respiratory distress. Vasaka tea pre- and co-treatment dose-dependently inhibited MUC5AC mRNA induction in cells treated with wood smoke particles. This correlated with TRPA1 inhibition, an attenuation of ER stress, and AEC damage/death, among other effects. Induction of mRNA for Anterior Gradient 2 (AGR2), an ER chaperone/disulfide isomerase required for MUC5AC production, and TRP vanilloid-3 (TRPV3), a gene that suppresses ER stress and wood smoke particle-induced cell death, were also attenuated. Variable inhibition of TRPA1, ER stress, and MUC5AC mRNA induction was observed using selected chemicals identified in Vasaka tea including vasicine, vasicinone, apigenin, 9-oxoODE, and 9,10-EpOME. 9,10-EpOME and apigenin were the most cytoprotective and mucosuppressive. Cytochrome P450 1A1 mRNA was also induced by Vasaka tea and wood smoke particles. Inhibition of CYP1A1 enhanced ER stress and MUC5AC mRNA expression, suggesting a role in producing protective oxylipins in stressed cells. The results provide mechanistic insights and support for the purported benefits of Vasaka tea in treating lung inflammatory conditions, raising the possibility of further development as a preventative therapy.
Project description:The de novo Autism Spectrum Disorder RELN R2290C Mutation Reduces Reelin Secretion and Increases Protein Disulfide Isomerase Expression
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:To understand the immunomodulation roles of Ixodes scapularis protein disulfide isomerase A6 (IsPDIA6), we utilized RNA sequencing (RNA-seq) to investigate the effect of IsPDIA6 on the murine transcriptome.
Project description:Translational research is commonly performed in the C57B6/J mouse strain, chosen for its genetic homogeneity and phenotypic uniformity. Here, we evaluate the suitability of the white-footed deer mouse (Peromyscus leucopus) as a model organism for aging research, offering a comparative analysis against C57B6/J and diversity outbred (DO) Mus musculus strains. Our study includes comparisons of body composition, skeletal muscle function, and cardiovascular parameters, shedding light on potential applications and limitations of P. leucopus in aging studies. Notably, P. leucopus exhibits distinct body composition characteristics, emphasizing reduced muscle force exertion and a unique metabolism, particularly in fat mass. Cardiovascular assessments showed changes in arterial stiffness, challenging conventional assumptions and highlighting the need for a nuanced interpretation of aging-related phenotypes. Our study also highlights inherent challenges associated with maintaining and phenotyping P. leucopus cohorts. Behavioral considerations, including anxiety-induced responses during handling and phenotyping assessment, pose obstacles in acquiring meaningful data. Moreover, the unique anatomy of P. leucopus necessitates careful adaptation of protocols designed for Mus musculus. While showcasing potential benefits, further extensive analyses across broader age ranges and larger cohorts are necessary to establish the reliability of P. leucopus as a robust and translatable model for aging studies.
Project description:AGR2 is an oncogenic endoplasmic reticulum (ER)-resident protein disulfide isomerase. AGR2 protein has a relatively unique property for a chaperone in that it can bind sequence-specifically to a peptide motif (TTIYY). A synthetic TTIYY-containing peptide column can be used to affinity-purify AGR2 from crude lysates highlighting peptide selectivity in complex mixtures. Hydrogen-deuterium exchange mass spectrometry localized the dominant region in AGR2 that interacts with the TTIYY peptide to within a structural loop from amino acids 131-135 (VDPSL). A peptide binding site consensus of Tx[IL][YF][YF] was developed for AGR2 by measuring its activity against a alanine mutagenized synthetic peptide library. Screening the human proteome for proteins harboring this consensus motif revealed an enrichment in transmembrane proteins and we focus on validating EpCAM as one such oncogenic protein. Recombinant AGR2 and EpCAM proteins formed a dose-dependent protein-protein interaction in vitro. Proximity ligation assays demonstrated that endogenous AGR2 and EpCAM protein associate in cells. Introducing a single alanine mutation in EpCAM at Tyr251 attenuated its binding to AGR2 in vitro and in cells. Hydrogen-deuterium exchange mass spectrometry was used to identify a stable binding site for AGR2 on EpCAM, adjacent to the TILYY motif and surrounding EpCAM’s detergent binding site. Together, these data define a dominant peptide-binding site on AGR2 that mediates its specific peptide-binding function. A model client protein, EpCAM, is proposed for AGR2 to study how an ER-resident chaperone can dock specifically and regulate assembly of a protein destined for the secretory pathway.
Project description:BackgroundCopy number variation is an important dimension of genetic diversity and has implications in development and disease. As an important model organism, the mouse is a prime candidate for copy number variant (CNV) characterization, but this has yet to be completed for a large sample size. Here we report CNV analysis of publicly available, high-density microarray data files for 351 mouse tail samples, including 290 mice that had not been characterized for CNVs previously.ResultsWe found 9634 putative autosomal CNVs across the samples affecting 6.87% of the mouse reference genome. We find significant differences in the degree of CNV uniqueness (single sample occurrence) and the nature of CNV-gene overlap between wild-caught mice and classical laboratory strains. CNV-gene overlap was associated with lipid metabolism, pheromone response and olfaction compared to immunity, carbohydrate metabolism and amino-acid metabolism for wild-caught mice and classical laboratory strains, respectively. Using two subspecies of wild-caught Mus musculus, we identified putative CNVs unique to those subspecies and show this diversity is better captured by wild-derived laboratory strains than by the classical laboratory strains. A total of 9 genic copy number variable regions (CNVRs) were selected for experimental confirmation by droplet digital PCR (ddPCR).ConclusionThe analysis we present is a comprehensive, genome-wide analysis of CNVs in Mus musculus, which increases the number of known variants in the species and will accelerate the identification of novel variants in future studies.