Project description:In this study, we sought to thoroughly characterize the liver pathophysiology of a human transgenic mouse model for alpha-1 antitrypsin deficiency (AATD) with a strong manifestation of AATD-mediated liver disease. Male and female transgenic mice for normal variant human alpha-1 antitrypsin (Pi*M) and mutant human alpha-1 antitrypsin (Pi*Z) at 3 and 6 months of age with a C57BL/6J background were subjected to study. The progression of hepatic accumulation of mutant alpha-1 antitrypsin (ZAAT), hepatocyte injury, steatosis, liver inflammation and fibrotic features of this mouse model were monitored by performing an in vivo study.
Project description:Whole genome mRNA and microRNA profiling of bronchoalveolar lavage (BAL) and peripheral blood mononuclear cell (PBMC) in Alpha-1 Antitrypsin Deficiency patients with PiZZ or PiMZ alpha-1 antitrypsin genotypes
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.
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.
Project description:Human induced pluripotent stem cells (hIPSCs) represent a unique opportunity for regenerative medicine since they offer the prospect of generating unlimited quantities of cells for autologous transplantation as a novel treatment for a broad range of disorders. However, the use of hIPSCs in the context of genetically inherited human disease will require correction of disease-causing mutations in a manner that is fully compatible with clinical applications. We analyzed hiPSC line and genetically modified derivatives using high-density SNP array to investigate genomic instability associated reprogramming and genetic modification. Primary iPSC lines derived from patients with alpha-1 antitrypsin deficiency were generated. This genetic disorder is caused by homozygous mutation (Glu342Lys) in the SERPINA1 gene. We carried out mutation correction by 2 steps: zinc-finger nuclease-stimuated gene targeting and piggyBac trasnsposon-mediated selection cassette elimination. Parental fibroblast lines, primary iPSC lines and homozygously targeted iPSC lines were subjected to SNP genotyping using Illumina CytoSNP-12 BeadChiP.
