Stem Cells

Fibro/adipogenic progenitors (FAPs) are skeletal muscle stromal cells that support regeneration of injured myofibers and their maintenance in healthy muscles. FAPs are related to mesenchymal stem cells (MeSCs) found in other adult tissues, but there is poor understanding of the extent of similarity between these cells. Using single cell RNA sequencing (scRNA-seq) datasets from multiple mouse tissues we have performed comparative transcriptomic analysis between these cells.

Stem and progenitor cells residing in the intestinal crypts drive the majority of colorectal cancers (CRCs), yet vascular contribution to this niche remains largely unexplored. VEGFA is a key driver of physiological and tumor angiogenesis. Accordingly, current anti-angiogenic cancer therapies target the VEGFA pathway. Here we report that in CRC expansion of the stem/progenitor pool in intestinal crypts requires VEGFA-independent growth and remodeling of blood vessels.

Intestinal cells marked by Lgr5 function as tissue-resident stem cells that sustain the homeostatic replenishment of the epithelium. By incorporating a diphtheria toxin receptor (DTR) cassette linked to the Lgr5 coding region, native Lgr5-expressing cells are susceptible to ablation upon DT administration in vivo. A similar strategy can be used for Lgr5-expressing cells within organoids established from DTR models. Together, these in vivo and in vitro approaches will facilitate dissection of the roles of Lgr5-expressing cells residing in different tissue compartments.

Dysfunction or loss of limbal stem cells can result in limbal stem cell deficiency (LSCD), a disease that cause corneal opacity, pain, and loss of vision. Cultivated limbal epithelial transplantation (CLET) can be used to restore stem cell niche homeostasis and replenish the progenitor pool. Transplantation has been reported with high success rate, but there is an unmet need of prognostic markers that correlate with clinical outcomes.

02 May 2022: This Accepted Article published in error. The article is under embargo and will publish in Early View in July 2022.This article is protected by

After birth, the intestine undergoes major changes to shift from an immature proliferative state to a functional intestinal barrier. By combining inducible lineage tracing and transcriptomics in mouse models, we identify a prodifferentiation PDGFRαHigh intestinal stromal lineage originating from postnatal LTβR+ perivascular stromal progenitors. The genetic blockage of this lineage increased the intestinal stem cell pool while decreasing epithelial and immune maturation at weaning age, leading to reduced postnatal growth and dysregulated repair responses.

RESULTS : Short-term lineage tracing data showed that _Lrig1_, _Lgr6_ and _Axin2_ label basal cells in MG ducts and acini. Long-term lineage tracing results showed that clones of labeled cells persist through multiple rounds of ductal and acinar renewal and give rise to differentiated progeny, identifying _Lrig1_+, _Lgr6_+ and _Axin2+_ ductal and acinar basal cells as self-renewing SCs. Forced expression of GLI2ΔN enhanced basal proliferation, caused expansion of _Lrig1_+ SCs, and lead to replacement of lipid-filled meibocytes by proliferative and poorly differentiated acinar cells.

Abstract Unavailable

The milestone achievement of reprogramming a human somatic cell into a pluripotent stem cell by Yamanaka and Takahashi in 2007 has changed the stem cell research landscape tremendously. Their discovery opened the unprecedented opportunity to work with human-induced pluripotent stem cells and the differentiated progeny thereof, without major ethical restrictions.

Hippocampal neurogenesis declines with aging. Wnt ligands and antagonists within the hippocampal neurogenic niche regulate the proliferation of neural progenitor cells and the development of new neurons, and the changes of their levels in the niche mediate aging-associated decline of neurogenesis. We found that RNA-binding protein LIN28A remained existent in neural progenitor cells and granule neurons in the adult hippocampus and that it decreased with aging.