Biology subjects

Matesic, L. E.

Publications and source records attributed to Matesic, L. E..

3 recordsLinked to original sources

bioRxiv2025

Identification and Validation of an Interaction between the E3 Ubiquitin Ligase WWP1 and the Transcriptional Co-Activator WBP2 in the Human Heart

Impaired proteostasis is one of the cellular hallmarks of aging, and the ubiquitin-proteosome system is a fundamental driver of proteostasis. As an E3 ubiquitin ligase, WW-domain containing protein 1 (WWP1) expression and activity are tightly regulated in cells, while its deregulation has been described in cancer, in neurodegenerative diseases, and in heart failure. However, the protein-protein interaction network of WWP1 is understudied, particularly in the heart. Here, we conducted a yeast-two hybrid (Y2H) screen of a human heart library and identified 21 putative WWP1 interactors, including 12 whose expression and potential function in the heart were previously unappreciated. Chief among these was WBP2 (WW domain binding protein 2), an oncogenic transcriptional co-activator. Utilizing immunofluorescence, it was confirmed that endogenous WWP1 co-localizes with WBP2 in human heart tissue, and, using the Y2H system, we showed that this interaction is dependent upon the associations between WW domains 1 and 3 from WWP1 and PY domains 2 and 3 of WBP2. In total, these data serve as a launching pad to identify broader protein networks regulated by WWP1 and the regions of interaction which might be targetable to reduce hallmarks of cellular aging.

molecular biology↗

bioRxiv2025

Endogenous gene editing of alveolar organoids reveals that expression of pathogenic variant SFTPC-I73T disrupts endosomal function, epithelial polarity and wound healing

BackgroundIdiopathic pulmonary fibrosis is a fatal lung disease of progressive lung parenchymal scarring caused by the aberrant response of an alveolar epithelium repeatedly exposed to injury. Understanding epithelial dysfunction has been hampered by the lack of physiological alveolar type 2 (AT2) cell models and defined disease triggers. Monogenic forms of familial pulmonary fibrosis (FPF) caused by toxic gain-of-function variants provide an opportunity to investigate early pathogenic events. One such variant, surfactant protein C (SFTPC)-I73T, abnormally localises within AT2 cells and causes their dysfunction. MethodsWe used base editing of fetal lung-derived AT2 (fdAT2) organoids to create a heterozygous disease model of endogenous SFTPC-I73T expression. We also created an inducible overexpression system to interrogate temporal changes associated with SFTPC-I73T expression. We cultured fdAT2 both in 3D culture and at air-liquid interface to understand the importance of polarity cues and air exposure on disease phenotypes. ResultsIn our heterozygous endogenous expression system, we found that fdAT2 expressing SFTPC-I73T grew without a lumen and were unable to correctly polarise. SFTPC-I73T accumulated with time and caused gross enlargement of early endosomes, preventing correct apico-basal trafficking of multiple endosomally trafficked cargoes including polarity markers and cell adhesion proteins. This phenotype was exacerbated by air exposure and led to loss of epithelial monolayer integrity and abnormal wound healing after injury. ConclusionUsing endogenous gene editing for the first time in differentiated alveolar organoids, we have demonstrated that the pathogenic effects of SFTPC-I73T are mediated through endosomal dysfunction and abnormal epithelial organisation. This has important implications for AT2 function in vivo.

cell biology↗

bioRxiv2023

A novel human fetal lung-derived alveolar organoid model reveals mechanisms of surfactant protein C maturation relevant to interstitial lung disease

Alveolar type 2 (AT2) cells maintain lung health by acting as stem cells and producing pulmonary surfactant1-3. AT2 dysfunction underlies many lung diseases including interstitial lung disease (ILD), in which some inherited forms result from mislocalisation of surfactant protein C (SFTPC) variants4,5. Disease modelling and dissection of mechanisms remains challenging due to complexities in deriving and maintaining AT2 cells ex vivo. Here, we describe the development of expandable adult AT2-like organoids derived from human fetal lung which are phenotypically stable, can differentiate into AT1-like cells and are genetically manipulable. We use these organoids to test key effectors of SFTPC maturation identified in a forward genetic screen including the E3 ligase ITCH, demonstrating that their depletion phenocopies the pathological SFTPC redistribution seen for the SFTPC-I73T variant. In summary, we demonstrate the development of a novel alveolar organoid model and use it to identify effectors of SFTPC maturation necessary for AT2 health.

cell biology↗