Biomedical subjects

Daniel J Wegner

Publications and source records attributed to Daniel J Wegner.

3 recordsLinked to original sources

PubMed2025

Lentiviral-mediated gene complementation rescues pathogenic ABCA3 variants.

The ATP-binding cassette subfamily A member 3 (ABCA3) protein on the limiting membrane of lamellar bodies in alveolar type 2 (AT2) cells transports phospholipids required for pulmonary surfactant assembly. ABCA3 deficiency results from biallelic pathogenic variants in ABCA3 and causes progressive neonatal respiratory failure or childhood interstitial lung disease (chILD). Supportive/compassionate care or lung transplantation are the only current definitive treatments for ABCA3 deficiency and progressive respiratory failure. Complementing dysfunctional ABCA3 by gene addition has therapeutic potential. Previous studies show that repairing or complementing ABCA3 in induced pluripotent stem cell (iPSC)-derived AT2 cells rescues lamellar body morphology and surfactant phospholipid composition. Pathogenic variants disrupt ABCA3 function through altered protein trafficking (type 1) or by impaired phospholipid transport (type 2) into lamellar bodies. Here we tested ABCA3 gene complementation using a human pulmonary epithelial cell line (A549) with a genomically silenced ABCA3 locus (ABCA3 KO). From this line, additional cell lines that stably express individual ABCA3 variant cDNA constructs from a single genomic locus were tested: L101P (type 1), E292V (type 2), E690K (type 2), or wild-type ABCA3. Lentiviral-mediated ABCA3 delivery to each cell line partially rescued localization to LAMP3+ vesicles, lamellar body-like structure morphology, and cell proliferation. A functional assay measuring NF-κB signaling suggested that ABCA3 complementation ameliorated aberrant inflammatory signaling in E292V or E690K (type 2) mutant lines, but not in L101P (type 1) or knockout lines. These studies highlight the therapeutic potential of gene addition as well as differences between ABCA3 pathogenic variants that may influence genetic therapy outcomes.

ABCA3 deficiency↗

PubMed2005

Genetic variant characterization in intron 4 of the surfactant protein B gene.

Genetic variants in intron 4 of the surfactant protein B gene SFTPB have been associated with pulmonary morbidity in newborn infants and adults. Genetic variant discovery in intron 4 requires high fidelity polymerase amplification due to a variable number of intermotif dinucleotide repeats and reliable characterization of alleles genetically distinct due to insertion, deletion, or both of 11 conserved sequence motifs. To optimize genetic variant discovery, we selected a high fidelity polymerase enzyme by replicate amplification and compared automated sequencing with agarose gel electrophoresis for all variant alleles (N=68) in a cohort of Missouri infants with (N=187) and without (N=53) respiratory distress. We identified and characterized six new alleles based on sequence motifs and two pairs of variant alleles with similar mobilities by agarose gel electrophoresis but distinct motif sequences. We confirmed uniformity of invariant alleles by sequencing (N=77). Logistic regression using race and intron 4 genotype for infants > or = 35 weeks gestation suggested that the invariant allele was independently associated with increased risk of respiratory distress (OR for the invariant allele 2.7, 95% CI 1.0-7.2). Reliable characterization of genetic variants in intron 4 requires both a high fidelity polymerase and sequencing of variant alleles.

Base Sequence↗

PubMed2004

Informed consent for genetic research.

BACKGROUND: Rapid technological advances in genetic research and public concern about genetic discrimination have led to anticipatory safeguards in the informed consent process in the absence of legal examples of proven discrimination. Despite federal and state regulations to restrict access to personal health information, including genetic information, institutional review boards have required the addition of language to informed consent documents that warns about the risks of discrimination with participation in genetic research. OBJECTIVE: To determine the reasons that families refused consent for their infant's participation in a study evaluating a genetic cause of respiratory distress syndrome. DESIGN: Survey conducted between February 1, 2002, and March 31, 2003. SETTING: Academic, tertiary free-standing children's hospital. PARTICIPANTS: A convenience sample of 465 families were approached for consent. The 135 families who refused consent were surveyed. MAIN OUTCOME MEASURES: Reasons for refusal. RESULTS: Of the nonconsenting families, 79% spontaneously and specifically identified institutionally required language in our consent form concerning the risk of denial of access to health insurance and employment as the primary reason for refusal; 97% indicated that their fears resulted directly from language in our consent form. Only 20% of families who refused consent cited inadequate time to consider the study. CONCLUSIONS: The institutionally required description of risk of genetic discrimination due solely to participation in genetic research was the primary reason for refusal to consent in this cohort. Information about federally and institutionally mandated protections for confidentiality of participants in genetic research should be included in the informed consent document to balance the description of hypothetical risks and more accurately inform subjects.

Employment↗