Selective inheritance of sub-cellular components has emerged as a mechanism guiding stem cell fate after asymmetric cell divisions. Peroxisomes play a crucial role in multiple metabolic processes such as fatty acid metabolism and reactive oxygen species detoxification, but the apportioning of peroxisomes during stem cell division remains understudied. Here, we develop a mouse model and labeling technique to follow the dynamics of distinct peroxisome age-classes, and find that old peroxisomes are inherited by the daughter cell retaining full stem cell potency in mammary and epidermal stem cell divisions. Old peroxisomes carry Glucose-6-phosphate-dehydrogenase, whose specific location on the peroxisomal membrane promotes stem cell function by facilitating peroxisomal ether lipid synthesis. Our study demonstrates age-selective apportioning of peroxisomes in vivo, and unveils how functional heterogeneity of peroxisomes is utilized by asymmetrically dividing cells to metabolically divert the fate of the two daughter cells.
© 2025. The Author(s).

Defining the trajectory of cells during differentiation and disease is key for uncovering the mechanisms driving cell fate and identity. However, trajectories of human cells remain largely unexplored due to the challenges of studying them with human samples. In this study, we investigate the proteome trajectory of iPSCs differentiation to hepatic stellate cells (diHSCs) and identify RORA as a key transcription factor governing the metabolic reprogramming of HSCs necessary for diHSCs' commitment, identity, and activation. Using RORA deficient iPSCs and pharmacologic interventions, we show that RORA is required for early differentiation and prevents diHSCs activation by reducing the high energetic state of the cells. While RORA knockout mice have enhanced fibrosis, RORA agonists rescue multi-organ fibrosis in in vivo models. Notably, RORA expression correlates negatively with liver fibrosis and HSCs activation markers in patients with liver disease. This study reveals that RORA regulates cell metabolic plasticity, important for mesoderm differentiation, pericyte quiescence, and fibrosis, influencing cell commitment and disease.
© 2025. The Author(s).

ABSTRACT The considerably slow pace of human brain development correlates with an evolutionary increase in brain size, cell numbers, and expansion of neuronal structures, with axon tracts undergoing an even greater evolutionary increase than other neuronal domains. However, whether tempo is responsible for these differences in magnitude, and how, remains to be determined. Here, we used brain organoids to investigate this and observed that human axon tracts spend more time growing and extend farther compared to those of mice, independent of their tissue environment. Single cell RNA sequencing analysis pointed to a subset of calcium-permeable ion channels expressed throughout neuron development, including during axon tract outgrowth. Calcium imaging during early neuron development consistently revealed a reduced calcium influx in human neurons compared to mouse neurons. Stimulating calcium influx and increasing cAMP levels resulted in premature halting of axon tract outgrowth and shorter axon tracts, mimicking the mouse phenotype, while abrogating calcium influx led to an even longer phase of axon tract outgrowth and longer axon tracts in humans. Thus, evolutionary differences in calcium regulation set the tempo of neuronal development, by extending the time window to foster the more elaborated human neuron morphology.

The potential use of pro-senescence therapies, known as TIS (Therapy-Induced Senescence), for the treatment of colorectal cancer (CRC) generated significant interest since they require lower doses compared to those required for inducing apoptosis. However, the senescent cell cycle-arrested cancer cells are long-lived, and studies have revealed escape mechanisms contributing to tumor recurrence. To deepen our understanding of the survival pathways used by senescent cancer cells, we delved into the potential involvement of the hexosamine biosynthetic pathway (HBP). HBP provides UDP-GlcNAc, the substrate for O-GlcNAc transferase (OGT), which catalyzes O-GlcNAcylation, a post-translational modification implicated in regulating numerous cellular functions and aberrantly elevated in CRC. In this study, we demonstrated, in the p53-proficient colon cancer cell lines HCT116 and LS174T, that TIS induced by low-dose SN38 or etoposide treatment was accompanied with a decrease of GFAT (the rate limiting enzyme of the HBP), OGT and O-GlcNAcase (OGA) expression correlated with a slight reduction in O-GlcNAcylation levels. Further decreasing this level of O-GlcNAcylation by knocking-down GFAT or OGT redirected the cellular response to subtoxic chemotherapy doses from senescence to apoptosis, in correlation with an enhancement of DNA damages. Pharmacological inhibition of OGT with OSMI-4 in HCT116 and LS174T cells and in a patient-derived colon tumoroid model supported these findings. Taken together, these results suggest that combing O-GlcNAcylation inhibitors to low doses of conventional chemotherapeutic drugs could potentially reduce treatment side effects while preserving efficacy. Furthermore, this approach may increase treatment specificity, as CRC cells exhibit higher O-GlcNAcylation levels compared to normal tissues.
© 2024. The Author(s).

Recent collaborative genome-wide association studies (GWAS) have identified >200 independent loci contributing to risk for schizophrenia (SCZ). The genes closest to these loci have diverse functions, supporting the potential involvement of multiple relevant biological processes, yet there is no direct evidence that individual variants are functional or directly linked to specific genes. Nevertheless, overlap with certain epigenetic marks suggest that most GWAS-implicated variants are regulatory. Based on the strength of association with SCZ and the presence of regulatory epigenetic marks, we chose one such variant near TSNARE1 and ADGRB1, rs4129585, to test for functional potential and assay differences that may drive the pathogenicity of the risk allele. We observed that the variant-containing sequence drives reporter expression in relevant neuronal populations in zebrafish. Next, we introduced each allele into human induced pluripotent cells and differentiated four isogenic clones homozygous for the risk allele and five clones homozygous for the non-risk allele into neural progenitor cells. Employing RNA sequencing, we found that the two alleles yield significant transcriptional differences in the expression of 109 genes at a false discovery rate (FDR) of <0.05 and 259 genes at a FDR of <0.1. We demonstrate that these genes are highly interconnected in pathways enriched for synaptic proteins, axon guidance, and regulation of synapse assembly. Exploration of genes near rs4129585 suggests that this variant does not regulate TSNARE1 transcripts, as previously thought, but may regulate the neighboring ADGRB1, a regulator of synaptogenesis. Our results suggest that rs4129585 is a functional common variant that functions in specific pathways likely involved in SCZ risk.
Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.