Biology subjects

Eisner, C.

Publications and source records attributed to Eisner, C..

4 recordsLinked to original sources

bioRxiv2026

The nail mesenchyme creates a regeneration-specific ligand environment that orchestrates mammalian regeneration versus fibrotic wound healing

The adult digit tip is one of a few privileged mammalian tissues that regenerate. Here, we asked why this is so. Using single cell spatial transcriptomics and genetic mouse models we show regeneration requires the nail organ and associated nail mesenchyme, and that in their absence fibrotic wound-healing occurs. We show the nail organ/mesenchyme orchestrates a highly-organized regenerative response that includes reprogramming of tissue-resident mesenchymal cells to a blastema state. It does this by creating a regeneration-specific ligand environment that includes multiple BMPs. Loss of the resultant downstream BMP signaling by genetic deletion of Smad4 in all mesenchymal cells or specifically in the nail mesenchyme inhibits multiple aspects of the regenerative response, including expression of regeneration-specific ligands. Thus, the nail mesenchyme creates a BMP-rich local ligand environment that reprograms mesenchymal cells and orchestrate tissues regeneration versus fibrotic wound-healing, findings with implications for tissue repair and anti-fibrosis strategies.

cell biology↗

bioRxiv2025

Single cell approaches define the murine leptomeninges:cortical brain interface as a distinct cellular neighborhood comprised of neural and nonneural cell types

The interface between the brain surface and the adjacent meninges is a selective barrier regulating fluid, protein and immune cell exchange between the CNS and periphery. However, the cell types that form this important interface are not yet fully defined. To address this limitation, we have used single cell RNA-sequencing (scRNA-seq) and single cell spatial transcriptomics together with morphological lineage tracing and immunostaining to analyze the adult murine cortex. We show that the cortical interface is comprised of three major cell types, leptomeningeal cells, border astrocytes and tissue-resident macrophages. On the peripheral side the interface is comprised of transcriptionally-distinct PDGFR-positive leptomeningeal mesenchymal cells that are intermingled with macrophages. This leptomeningeal pial layer is lined by a population of transcriptionally-distinct border astrocytes. The interface neighborhood is rich in growth factor mRNAs, including many leptomeningeal ligands predicted to act on both the border astrocytes and macrophages. On the CNS side of the interface is the relatively cell-sparse cortical layer one containing interneurons, microglia, parenchymal astrocytes, oligodendrocyte precursor cells and oligodendrocytes. Except for the border astrocytes, layer one cells are not closely-associated with the interface, suggesting that secreted ligands may be the major way the brain interface communicates with the underlying cortical parenchyma. Thus, our data provide a molecular/cellular resource describing the brain interface cell types and their interactions, thereby enabling future studies asking how this distinct cellular compartment regulates CNS:periphery interactions. Significance StatementRecent years have seen significant progress in identifying the diverse cell types within the meningeal space. However, the mechanisms by which these cells interact with glial and neuronal cells in layer one of the adult murine cortex remain poorly understood. During development, communication between radial precursors and meningeal layers is crucial for proper brain formation, but the role of this interaction in adulthood is still unclear. Additionally, how resident immune cells in the leptomeningeal space signal to layer one cortical cells or meningeal mesenchymal cells during homeostasis remains an open question. Understanding the identity, location, and interactions of these cells is essential for unraveling the complex dynamics at this critical brain interface.

neuroscience↗

bioRxiv2022

Mesenchymal Progenitors set the homeostatic inflammatory milieu via the TAK1-NFkB axis.

The ability of mesenchymal stromal cells to modulate inflammation is at the basis of the ongoing interest in their therapeutic potential. Yet, reliable success in clinical trials is limited, possibly due to a limited understanding of their impact on the inflammatory milieu in physiological conditions. Here we show that, at steady state, mesenchymal progenitors regulate the balance between type 1 and type 2 inflammatory milieus by acting on innate immune cells through the TAK1-NFkB pathway. Suppressing the constitutive activity of this pathway in MPs leads to skewing of the immune system toward systemic Type 2 inflammation (Th2). These changes have significant effects on diseases with an important inflammatory component, leading to a worsening of disease in a preclinical model of Th2-dependent Asthma, and a reduction of symptoms associated with Th1/Th17-dependent experimental autoimmune encephalitis.

cell biology↗

bioRxiv2022

Spatial compartmentalization of signalling imparts source-specific functions on secreted factors

Efficient regeneration requires multiple cell types acting in a coordination. To better understand the intercellular networks involved and how they change when regeneration fails, we profiled the transcriptome of hematopoietic, stromal, myogenic, and endothelial cells over 14 days following acute muscle damage. A time-resolved computational model of interactions was generated, and VEGFA-driven endothelial engagement was identified as a key differentiating feature in models of successful and failed regeneration. In addition, it revealed that the majority of secreted signals, including VEGFA, are simultaneously produced by multiple cell types. To test whether the cellular source of a factor determines its function, we deleted VEGFA from two cell types residing in close proximity, stromal and myogenic progenitors. By comparing responses to different types of damage, we found that myogenic and stromal VEGFA have distinct functions in regeneration. This suggests that spatial compartmentalization of signaling plays a key role in intercellular communication networks. HighlightsO_LILigand-receptor signaling redundancy during skeletal muscle regeneration C_LIO_LIInflammatory cells, and muscle and fibro/adipogenic progenitors produce VEGFA C_LIO_LIVEGFA from muscle progenitors control their proliferation after muscle damage C_LIO_LIVEGFA from FAP controls angiogenesis only after ischemic damage C_LI eTOC blurbGroppa et al. performed a novel time-resolved bioinformatics analysis that revealed extensive ligand-receptor redundancy among the cell types contributing to skeletal muscle regeneration. They focused on one of these pathways, and showed that VEGFA from different cell types has distinct roles in regeneration.

cell biology↗