Biology subjects

Laselva, O.

Publications and source records attributed to Laselva, O..

5 recordsLinked to original sources

bioRxiv2024

Benchmarking organ-specific responses to therapies in tissues differentiated from Cystic Fibrosis patient derived iPSCs

Cystic Fibrosis (CF) is a life-shortening disease that is caused by mutations in the CFTR gene, a gene that is expressed in multiple organs. There are several primary tissue models of CF disease, including nasal epithelial cultures and rectal organoids, that are effective in reporting the potential efficacy of mutation-targeted therapies called CFTR modulators. However, there is the well-documented variation in tissue dependent, therapeutic response amongst CF patients, even those with the same CF-causing mutation. Hence, there is an interest in developing strategies for benchmarking therapeutic efficacy in different organs relative to isogenic controls. In this study, we evaluated the CFTR chloride channel response to the highly effective CFTR modulator: Trikafta, in CF patient specific, iPSC-derived colonic and airway cultures relative to mutation-corrected (non-CF) tissues from that same individual. We measured pharmacological rescue in both tissues, but interestingly, Trikafta treatment resulted in different levels of functional rescue in the two tissues relative to the relevant isogenic control. This proof-of-concept study lays the groundwork for future comparisons of patient-specific CF therapeutic responses in both pulmonary and extra-pulmonary systems.

pharmacology and toxicology↗

bioRxiv2021

High-throughput functional analysis of CFTR and other apically localized channels in iPSC derived intestinal organoids

Induced Pluripotent Stem Cells (iPSCs) can be differentiated into epithelial organoids that recapitulate the relevant context for CFTR and enable testing of therapies targeting Cystic Fibrosis (CF)-causing mutant proteins. However, to date, CF-iPSC-derived organoids have only been used to study pharmacological modulation of mutant CFTR channel activity and not the activity of other disease relevant membrane protein constituents. In the current work, we describe a high-throughput, fluorescence-based assay of CFTR channel activity in iPSC-derived intestinal organoids and describe how this method can be adapted to study other apical membrane proteins. In these proof-of-concept studies, we show how this fluorescence-based assay of apical membrane potential can be employed to study CFTR and ENaC channels and an electrogenic acid transporter in the same iPSC-derived intestinal tissue. This multiparameter phenotypic platform promises to expand CF therapy discovery to include strategies to target multiple determinants of epithelial fluid transport.

molecular biology↗

bioRxiv2021

A new platform for high-throughput therapy testing on iPSC-derived, immature airway from Cystic Fibrosis Patients

Induced pluripotent, stem cell (iPSC)-derived models of airway tissue have successfully modeled the primary defect in regulated chloride conductance caused by the major Cystic Fibrosis causing mutation, F508del. However, it remains unclear if iPSC-derived airway cultures can be used in high-throughput therapy development for F508del and rarer mutations. There is an urgent need for airway tissue models that reflect the variability of patient-specific responses and are scalable for therapy development. In the current work, we describe a robust, high-throughput fluorescence assay of mutant CFTR function in iPSCs differentiated to immature airway epithelium. This assay measures reproducible functional responses to modulators targeting either the major CF mutant F508del or the nonsense mutant: W1282X-CFTR. We show that the ranking of patient-specific responses to interventions in this stem-cell based model recapitulates the ranking observed in primary nasal epithelial cultures obtained from the same individuals. In summary, these proof-of-concept studies show that this novel platform has the potential to support therapy development and precision medicine for Cystic Fibrosis patients. One Sentence SummaryWe describe a fluorescence-based platform that enables high-throughput Cystic Fibrosis therapy testing using iPSCs differentiated to immature lung.

genomics↗

bioRxiv2021

Generation of functional ciliates cholangiocytes from human pluripotent stem cells

The derivation of mature functional cholangiocytes from human pluripotent stem cells (hPSCs) would provide a model for studying the pathogenesis of cholangiopathies and for developing novel therapies to treat them. Current differentiation protocols are not efficient and give rise to cholangiocytes that are not fully mature, limiting their therapeutic applications. Here, we describe a new strategy to generate functional hPSC-derived cholangiocytes that display many characteristics of mature bile duct cells including high levels of CFTR and the presence of primary cilia capable of sensing flow. With this level of maturation, these cholangiocytes are amenable for testing the efficacy of new cystic fibrosis drugs and for studying the role of cilia in cholangiocyte development and function. Transplantation studies showed that the mature cholangiocytes generate ductal structures in the liver of immunocompromised mice providing the first indication that it may be possible to develop cell-based therapies to restore bile duct function in patients with biliary disease.

cell biology↗

bioRxiv2018

Comprehensive mapping of Cystic Fibrosis mutations to CFTR protein identifies mutation clusters and molecular docking predicts corrector binding site

BackgroundCystic Fibrosis (CF) is caused by mutations in the CFTR gene, of which over 2000 have been reported to date. Mutations have yet to be analyzed in aggregate to assess their distribution across the tertiary structure of the CFTR protein, an approach that could provide valuable insights into the structure-function relationship of CFTR. In addition, the binding site of Class I correctors (VX-809, VX-661, C18) is not well understood.\n\nMethodsExonic CFTR mutations and mutant allele frequencies described in three curated databases (ABCMdb, CFTR1 and CFTR2, comprising >130,000 data points) were mapped to two different structural models: a homology model of full-length CFTR protein in the open-channel state, and a cryo-electron microscopy core-structure of CFTR in the closed-channel state. Immunoblotting confirmed the approximate binding site of Class I correctors, and molecular docking generated binding poses for their complex with the cryo-electron microscopy structure.\n\nResultsResidue positions of six high-frequency mutant CFTR alleles were found to spatially co-localize in CFTR protein, and a significant cluster was identified at the NBD1:ICL4 interdomain interface. Further, Class I correctors VX-809, VX-661 and C18 were shown to act via a similar mechanism in vitro, and a putative multi-domain corrector binding site near residues F374-L375 was predicted in silico.\n\nConclusionsOur results confirm the significance of interdomain interfaces as susceptible to disruptive mutation, and identify a putative corrector binding site. The structural pharmacogenomics approach of mapping mutation databases to protein models shows promise for facilitating drug discovery and personalized medicine for monogenetic diseases.

biochemistry↗