Pulmonary gain-of-function toxicity in alpha-1 antitrypsin deficiency
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE227210 | GEO | 2024/12/12
REPOSITORIES: GEO
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Project description:Background. Animal models of elastase intratracheal instillation have shown that elastase, unopposed by α-1 antitrypsin (AAT), can induce alveolar hemorrhage with ensuing macrophage inflammation and lung damage. Aim. To identify markers of alveolar hemorrhage and damage using bronchoalveolar lavage (BAL) samples and lung tissue explants from AAT deficient (AATD) subjects. Methods. BAL samples (17 patients, 15 controls) were evaluated for free heme and iron concentrations. Alveolar macrophage (AlvMac) activation patterns were assessed by RNA sequencing and validated in vitro using heme-stimulated monocyte-derived macrophages (MDM). Lung explants (7 patients, 4 controls) were evaluated for iron sequestration patterns, by Prussian blue stain and ferritin immunohistochemistry, and for ferritin iron imaging and elemental analysis by electron microscopy (EM). Tissue oxidative damage was assessed by 8-OHdG immunohistochemistry. Results. BAL showed significantly elevated free heme and iron concentrations at lobar level. BAL macrophage RNA sequencing showed innate proinflammatory activation, consistent with free heme activation. AATD tissue alveolar and interstitial macrophages showed elevated iron and ferritin accumulation in large lysosomes packed with iron oxide cores with degraded ferritin protein cages. AATD explants showed massive oxidative DNA damage in lung epithelial cells and macrophages. Conclusions. Identification of BAL and tissue markers of alveolar hemorrhage, together with the molecular and cellular evidence of macrophage innate pro-inflammatory activation and oxidative damage, consistent with free heme stimulation, provides ex vivo evidence for the pathogenetic role of elastase-induced alveolar hemorrhage AATD emphysema as shown in animal studies.
2023-04-25 | GSE194313 | GEO
Project description:Alpha-1-antitrypsin (AAT), a serine protease inhibitor produced mainly by the liver, is the third most abundant protein in plasma. Individuals who possess homozygous Z-AAT genotype have severe AAT deficiency and are at risk for early-onset emphysema, bronchiectasis, cirrhosis, panniculitis, and vasculitis. While a canonical receptor for AAT has not been identified, AAT can be internalized into the cytoplasm and is known to affect gene regulation. Since AAT has significant anti-inflammatory properties affecting many cell types including macrophages, we examined whether AAT binds the cytoplasmic glucocorticoid receptor (GR) in macrophages. We report the novel finding that AAT binds to GR in macrophages using several approaches, including co-immunoprecipitation, mass spectrometry, microscale thermophoresis, and in silico molecular modeling. We further demonstrate that AAT induction of angiopoietin-like 4 protein and AAT inhibition of lipopolysaccharide-induced nuclear factor-kappa B activation and interleukin-8 production are mediated, in part, through AAT–GR interaction. Furthermore, this interaction contributes to a host-protective role against Mycobacterium tuberculosis in macrophages. The interaction of AAT and GR described in this study identifies a mechanism for the anti-inflammatory and host-protective properties of AAT.
2022-08-24 | PXD030989 | Pride
Project description:in situ proteomic analysis (combining laser microdissection of hepatocytes and mass spectrometry analysis) on formalin-fixed paraffin-embedded (FFPE) human liver tissues of 4 ZZ-Alpha 1-Antitrypsin Deficiency (AATD) pediatric patients and 4 ZZ-AATD adult patients that underwent liver transplantation versus 3 WT individuals infants and 4 adults, and compared proteins differentially expressed in ZZ pediatric and in ZZ adult AATD patients.
2021-09-09 | PXD022994 | Pride
Project description:Alpha-1 antitrypsin deficiency (AATD) liver disease is characterized by marked heterogeneity in presentation and progression, despite a common underlying gene mutation, strongly suggesting the involvement of other genetic and/or epigenetic modifiers. Variation in clinical phenotype has added to the challenge of detection, diagnosis, and testing of new therapies in patients with AATD. We examined the contribution of DNA methylation (5-methylcytosine [5mC]) to AATD liver disease heterogeneity because 5mC responds to environmental and genetic cues and its deregulation is a major driver of liver disease. Using liver biopsies from adults with early-stage AATD and the ZZ genotype, genome-wide 5mC patterns were interrogated. We compared DNA methylation among patients with early AATD, and among patients with normal liver, cirrhosis, and hepatocellular carcinoma derived from multiple etiologic exposures, and linked patient clinical/demographic features. Global analysis revealed significant genomic hypomethylation in AATD liver-impacting genes related to liver cancer, cell cycle, and fibrosis, as well as key regulatory molecules influencing growth, migration, and immune function. Further analysis indicated that 5mC changes are localized, with hypermethylation occurring within a background of genome-wide 5mC loss and with patients with AATD manifesting distinct epigenetic landscapes despite their mutational homogeneity. By integrating clinical data with 5mC landscapes, we observed that CpGs differentially methylated among patients with AATD disease are linked to hallmark clinical features of AATD (e.g., hepatocyte degeneration and polymer accumulation) and further reveal links to well-known sex-specific effects of liver disease progression. Conclusion: Our data reveal molecular epigenetic signatures within this mutationally homogeneous group that point to ways to stratify patients for liver disease risk.
2019-06-10 | GSE119100 | GEO
Project description:α-1-antitrypsin (AAT) regulates protease activity in the lungs and liver. The presence of one or more copies of a mutant Z allele (AAT (E342K), called ATZ), results in low serum levels of ATZ along with intracellular inclusions of polymeric forms, causing lung emphysema and liver cirrhosis. Our experiments show that calreticulin (CRT), an endoplasmic reticulum (ER) glycoprotein chaperone, promotes the secretory trafficking of ATZ, enhancing the media to cell ratio. This effect is more specific for ATZ compared with AAT, and is only partially dependent on the glycan-binding site of CRT. The CRT-related chaperone calnexin (CNX) does not promote enhanced ATZ secretory trafficking, despite the higher cellular abundance of CNX-ATZ complexes. CRT deficiency alters the distributions of ATZ-ER chaperone complexes, increasing ATZ-BiP binding and inclusion body (IB) formation, and reducing ATZ interactions with components required for ER-Golgi trafficking. These findings indicate a novel role for CRT in promoting the secretory trafficking of a polymerogenic protein. Inefficient secretory trafficking of ATZ in the absence of CRT is coincident with enhanced accumulation of ER-derived ATZ IBs.
2020-09-24 | PXD020562 | Pride
Project description:Human α1-antitrypsin (AAT) is an abundant acute phase glycoprotein performing anti-protease, anti-apoptotic and immunomodulatory functions. Purified human plasma AAT used as a specific therapy for patients with lung emphysema and panniculitis due to inherited AAT deficiency, and it is beneficial in treating of other disorders. This therapy administered intravenously although other routes of administration are tested. Herein, we examined the transdermal application of native or recombinant AAT by using epiCS®, the 3D human epidermis equivalent reconstructed from human primary epidermal keratinocytes. Topically applied AAT protein (50µl, prepared in Hank`s balance solution, HBSS) freely diffused across epidermis layers in a concentration and time-dependent manner. We concluded that within 18 hours topically added 0.2 mg AAT well penetrates the stratum corneum and can be detected inside the cytosol of keratinocytes. Importantly, treatments with AAT did not induce obvious morphological changes in keratinocyte layers. Next, we supplemented culture medium with 100µg/ml of combined bacterial lipopolysaccharide (LPS) and peptidoglycan (PNG) mixture and incubated epiCS for 18h with or without the topical application of 0.2 mg AAT. Under these conditions, LPS/PNG triggered a strongly activation of epidermis model. Even though AAT exhibited a limited capacity to neutralize the effect of LPS/PNG, it lowered expression of IL-18 and IL-8, and preserved levels of filaggrin, an important protein for maintaining the epidermal barrier integrity. Our results suggest that the transdermal route for delivering AAT is worth exploration. If successful, this approach may offer easy-to-use therapy with AAT.
2020-05-21 | GSE150946 | GEO
Project description:Cigarette smoking is the leading cause of emphysema in the United States. Alveolar macrophages play a critical role in the inflammation-mediated remodeling of the lung parenchyma in emphysema. However, the exact gene pathways and the role of DNA methylation in moderating this pathological transformation are not known. In order to more exactly understand this process, we compared genome-wide expression and methylation signatures of alveolar macrophages isolated from heavy smokers with those isolated from non-smoking controls. We found enrichment of differential methylation in genes from immune system and inflammatory pathways as determined by standard pathway analysis. Consistent with recent findings, significant methylation changes were particularly enriched in the areas flanking CpG islands (CpG shores). Analysis of matching gene expression data demonstrated a parallel enrichment for changes in immune system and inflammatory pathways. We conclude that alveolar macrophages from the lungs of smokers demonstrate coordinated changes in DNA methylation and gene expression that link to inflammation pathways. We suggest that further studies of DNA methylation in immune and inflammation-related gene expression are needed to understand the pathogenesis of emphysema and other smoking-related diseases. Expression analysis of 13 smokers vs. 10 non-smokers on the Affymetrix Exon Array. This submission represents the expression component of the study.
2011-02-03 | E-GEOD-27002 | biostudies-arrayexpress
Project description:Chymotrypsin-like elastase 1 (CELA1) is a serine protease that is neutralized by alpha-1 antitrypsin (AAT) and prevents emphysema in a murine antisense oligonucleotide model of AAT-deficient emphysema. We tested the role of CELA1 in emphysema development in this genetic model of AAT-deficiency following tracheal lipopolysaccharide (LPS), 10 months of cigarette smoke (CS) exposure, aging, and a low-dose tracheal porcine pancreatic elastase (LD-PPE) model we developed. In this last model, we performed proteomic analysis to understand differences in lung protein composition. We were unable to show that AAT-deficient mice developed more emphysema than wild type with escalating doses of LPS.
2023-02-20 | MSV000091330 | MassIVE
Project description:Cigarette smoking is the leading cause of emphysema in the United States. Alveolar macrophages play a critical role in the inflammation-mediated remodeling of the lung parenchyma in emphysema. However, the exact gene pathways and the role of DNA methylation in moderating this pathological transformation are not known. In order to more exactly understand this process, we compared genome-wide expression and methylation signatures of alveolar macrophages isolated from heavy smokers with those isolated from non-smoking controls. We found enrichment of differential methylation in genes from immune system and inflammatory pathways as determined by standard pathway analysis. Consistent with recent findings, significant methylation changes were particularly enriched in the areas flanking CpG islands (CpG shores). Analysis of matching gene expression data demonstrated a parallel enrichment for changes in immune system and inflammatory pathways. We conclude that alveolar macrophages from the lungs of smokers demonstrate coordinated changes in DNA methylation and gene expression that link to inflammation pathways. We suggest that further studies of DNA methylation in immune and inflammation-related gene expression are needed to understand the pathogenesis of emphysema and other smoking-related diseases.
2011-02-03 | GSE27002 | GEO
Project description:Individuals homozygous for the "Z" mutation in alpha-1 antitrypsin deficiency are known to be at increased risk for liver disease. It has also become clear that some degree of risk is similarly conferred by the heterozygous state. A lack of model systems that recapitulate heterozygosity in human hepatocytes has limited the ability to study the impact of a single Z alpha-1 antitrypsin (ZAAT) allele on hepatocyte biology. Here, we describe the derivation of syngeneic induced pluripotent stem cells (iPSCs) engineered to determine the effects of ZAAT heterozygosity in iPSC-hepatocytes (iHeps). We find that heterozygous MZ iHeps exhibit an intermediate disease phenotype and share with ZZ iHeps alterations in AAT protein processing and downstream perturbations including altered endoplasmic reticulum (ER) and mitochondrial morphology, reduced mitochondrial respiration, and branch-specific activation of the unfolded protein response in cell subpopulations. Our model of MZ heterozygosity thus provides evidence that a single Z allele is sufficient to disrupt hepatocyte homeostatic function.
2022-12-06 | GSE198234 | GEO