Expansion of biliary epithelial cells (BECs) during ductular reaction (DR) is observed in liver diseases including cystic fibrosis (CF), and associated with inflammation and fibrosis, albeit without complete understanding of underlying mechanism. Using two different genetic mouse knockouts of b-catenin, one with b-catenin loss is hepatocytes and BECs (KO1), and another with loss in only hepatocytes (KO2), we demonstrate disparate long-term repair after an initial injury by 2-week choline-deficient ethionine-supplemented diet. KO2 show gradual liver repopulation with BEC-derived b-catenin-positive hepatocytes, and resolution of injury. KO1 showed persistent loss of b-catenin, NF-kB activation in BECs, progressive DR and fibrosis, reminiscent of CF histology. We identify interactions of b-catenin, NFkB and CF transmembranous conductance regulator (CFTR) in BECs. Loss of CFTR or b-catenin led to NF-kB activation, DR and inflammation. Thus, we report a novel b-catenin-NFkB-CFTR interactome in BECs, and its disruption may contribute to hepatic pathology of CF.
Raw RNA-seq data and gene count quantification were submitted to NCBI GEO data base with accession ID GSE155981
β-Catenin-NFkB-CFTR interactions in cholangiocytes regulate inflammation and fibrosis during ductular reactionNCBI Gene Expression Omnibus, GSE155981.
- Satdarshan P Monga
- Sungjin Ko
- Jacquelyn O Russell
- Satdarshan P Monga
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Animal experimentation: This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All animals were handled according to approved institutional animal care and use committee (IACUC) Protocol #: 19126451 of the University of Pittsburgh.
Human subjects: The study was conducted according to the guidelines of the Declaration of Helsinki, and approved by the Institutional Review Board of the University of Pittsburgh (STUDY19070068, STUDY20010114, and STUDY20040276 on 3/23/2021).
- Paul W Noble, Cedars-Sinai Medical Centre, United States
© 2021, Hu et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Imaging experiments reveal the complex and dynamic nature of the transcriptional hubs associated with Notch signaling.
Cylicins are testis-specific proteins, which are exclusively expressed during spermiogenesis. In mice and humans, two Cylicins, the gonosomal X-linked Cylicin 1 (Cylc1/CYLC1) and the autosomal Cylicin 2 (Cylc2/CYLC2) genes, have been identified. Cylicins are cytoskeletal proteins with an overall positive charge due to lysine-rich repeats. While Cylicins have been localized in the acrosomal region of round spermatids, they resemble a major component of the calyx within the perinuclear theca at the posterior part of mature sperm nuclei. However, the role of Cylicins during spermiogenesis has not yet been investigated. Here, we applied CRISPR/Cas9-mediated gene editing in zygotes to establish Cylc1- and Cylc2-deficient mouse lines as a model to study the function of these proteins. Cylc1 deficiency resulted in male subfertility, whereas Cylc2-/-, Cylc1-/yCylc2+/-, and Cylc1-/yCylc2-/- males were infertile. Phenotypical characterization revealed that loss of Cylicins prevents proper calyx assembly during spermiogenesis. This results in decreased epididymal sperm counts, impaired shedding of excess cytoplasm, and severe structural malformations, ultimately resulting in impaired sperm motility. Furthermore, exome sequencing identified an infertile man with a hemizygous variant in CYLC1 and a heterozygous variant in CYLC2, displaying morphological abnormalities of the sperm including the absence of the acrosome. Thus, our study highlights the relevance and importance of Cylicins for spermiogenic remodeling and male fertility in human and mouse, and provides the basis for further studies on unraveling the complex molecular interactions between perinuclear theca proteins required during spermiogenesis.