Patient-Induced Pluripotent Stem Cell-Derived Hepatostellate Organoids Establish a Basis for Liver Pathologies in Telomeropathies.

BACKGROUND & AIMS: Dyskeratosis congenita (DC) is a telomere biology disorder caused primarily by mutations in the DKC1 gene. Patients with DC and related telomeropathies resulting from premature telomere dysfunction experience multiorgan failure. In the liver, DC patients present with nodular hyperplasia, steatosis, inflammation, and cirrhosis. However, the mechanism responsible for telomere dysfunction-induced liver disease remains unclear. METHODS: We used isogenic human induced pluripotent stem cells (iPSCs) harboring a causal DC mutation in DKC1 or a CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/Cas9)-corrected control allele to model DC liver pathologies. We differentiated these iPSCs into hepatocytes (HEPs) or hepatic stellate cells (HSCs) followed by generation of genotype-admixed hepatostellate organoids. Single-cell transcriptomics were applied to hepatostellate organoids to understand cell type-specific genotype-phenotype relationships. RESULTS: Directed differentiation of iPSCs into HEPs and stellate cells and subsequent hepatostellate organoid formation revealed a dominant phenotype in the parenchyma, with DC HEPs becoming hyperplastic and also eliciting a pathogenic hyperplastic, proinflammatory response in stellate cells independent of stellate cell genotype. Pathogenic phenotypes in DKC1-mutant HEPs and hepatostellate organoids could be rescued via suppression of serine/threonine kinase AKT (protein kinase B) activity, a central regulator of MYC-driven hyperplasia downstream of DKC1 mutation. CONCLUSIONS: Isogenic iPSC-derived admixed hepatostellate organoids offer insight into the liver pathologies in telomeropathies and provide a framework for evaluating emerging therapies.

GSK3 inhibition rescues growth and telomere dysfunction in dyskeratosis congenita iPSC-derived type II alveolar epithelial cells.

Dyskeratosis congenita (DC) is a rare genetic disorder characterized by deficiencies in telomere maintenance leading to very short telomeres and the premature onset of certain age-related diseases, including pulmonary fibrosis (PF). PF is thought to derive from epithelial failure, particularly that of type II alveolar epithelial (AT2) cells, which are highly dependent on Wnt signaling during development and adult regeneration. We use human induced pluripotent stem cell-derived AT2 (iAT2) cells to model how short telomeres affect AT2 cells. Cultured DC mutant iAT2 cells accumulate shortened, uncapped telomeres and manifest defects in the growth of alveolospheres, hallmarks of senescence, and apparent defects in Wnt signaling. The GSK3 inhibitor, CHIR99021, which mimics the output of canonical Wnt signaling, enhances telomerase activity and rescues the defects. These findings support further investigation of Wnt agonists as potential therapies for DC-related pathologies.

A Body of Evidence: Barriers to Family Viewing After Death by Gun Violence.

BACKGROUND: Gun violence remains a staggering public health care crisis. Although viewing the victim's body is essential to the grieving process, this practice is not universally practiced in the trauma bay and may not be supported by nurses. This study investigates how trauma nurses perceive bereavement and the potential barriers to family viewing after death by gun violence. METHODS: A survey designed to assess demographics, current practices, knowledge of policies, and personal beliefs regarding family viewing after violent crime was sent electronically to members of the Society of Trauma Nurses. Participants were asked to rank the importance of 14 viewing barriers. Descriptive analysis and perception of barriers between those who did and did not permit viewing were compared using Mann-Whitney tests. *P < 0.05 is considered significant. RESULTS: Of the 212 participants, the majority were white, female nurses (86%), aged 30 to 60 y who worked in an urban or suburban setting (58% and 30%). Only 15% had a written hospital policy with the majority not knowing if the police (68%) or medical examiner (74%) had written policies. Despite lack of guidelines, viewings did routinely occur (68%), but only 37% permitted touching. Nurses who did not permit viewing were more likely to rank legal concerns and trauma bay environment as significant barriers. CONCLUSIONS: Although family viewing after gun violence frequently occurs in the trauma bay, there are significant barriers that are compounded by lack of formal policies. Collaboration with police and medical examiners could mitigate these fears while promoting a safe and more family-centered experience.