Biology subjects

Chandler-Militello, D.

Publications and source records attributed to Chandler-Militello, D..

4 recordsLinked to original sources

bioRxiv2025

In vivo selection and glymphatic delivery of AAV5 capsids engineered to target human glial progenitor cells

To establish a means of efficiently transducing human glial progenitor cells (hGPCs) in vivo with therapeutic transgenes, we targeted PDGFRA-driven Cre-recombinase expressing hGPCs in human glial chimeric mice with a library of capsid-modified, recombination-reported adeno-associated viruses (AAVs). PCR screening for gliotropic viral capsid sequences, filtered against visceral organs, identified a set of AAV5-based vectors that preferentially infected human GPCs and/or their derived astrocytes and oligodendrocytes in vivo, with minimal systemic infection. To maximize the intracerebral distribution of these viruses while minimizing their dosing and extracerebral spread, we paired their intracisternal delivery with systemic hypertonicity. This method exploited intracerebral glymphatic flow to bypass the blood-brain barrier, delivering AAV directly into the brain parenchyma. Glymphatic delivery of capsid-modified AAV5s, evolved on human GPCs in vivo, thus enables efficient, brain-wide transgene delivery to human glia and their progenitors in the adult brain, with minimal off-target transduction.

neuroscience↗

bioRxiv2025

Charting the transition from in vitro gliogenesis to the in vivo maturation of transplanted human glial progenitor cells

Neither rodent models nor in vitro studies of human cells adequately describe the molecular ontogeny of human glial progenitor cells (hGPCs). Here, we used scRNA-seq together with scATAC-Seq and CUT&TAG assessment of chromatin availability to track the in vitro genesis and in vivo differentiation of hGPCs from pluripotent stem cells (PSCs). In vitro, the hGPC pool comprised 4 transcriptionally-distinct subpopulations, each associated with a distinct pattern of chromatin accessibility and histone modification of stage-dependent genes. After the neonatal transplant of these cells into myelin-deficient shiverer mice, they differentiated further as astrocytes and oligodendrocytes. A combination of gene co-expression, motif enrichment, cell-trajectory, and cell-cell interaction analyses revealed that the host environment potentiated the context-dependent differentiation of the hGPCs, via their activation of distinct gene regulatory networks. Together, these data chart the process by which human PSC-derived GPCs are generated in vitro and diversify in vivo to mature as astrocytes and oligodendrocytes.

neuroscience↗

bioRxiv2020

Calcium-independent astrocytic lipid release modulates neuronal activity through Kv channels

An accumulating amount of data suggests that Ca2+-dependent gliotransmitter release plays a key role in the modulation of neuronal networks. Here, we tested the hypothesis that in response to agonist exposure, astrocytes release lipid modulators through activation of Ca2+-independent phospholipase A2 (iPLA2) activity. We found that cultured rat astrocytes treated with selective ATP and glutamatergic agonists released arachidonic acid (AA) and/or its derivatives, including the endogenous cannabinoid 2-arachidonoyl-sn-glycerol (2AG) and prostaglandin E2 (PGE2). Surprisingly, the buffering of cytosolic Ca2+ resulted in a sharp increase in agonist-induced lipid release by astrocytes. In addition, the astrocytic release of PGE2 increased miniature excitatory postsynaptic potentials (mEPSPs) by inhibiting the opening of neuronal Kv channels in brain slices. This study provides the first evidence showing that a Ca2+-independent pathway regulates the release of PGE2 from astrocytes and further demonstrates the functional role of astrocytic lipid release in the modulation of synaptic activity. SIGNIFICANCEUntil now, most studies that implicate astrocytes in the modulation of synaptic activity have focused on Ca2+-dependent release of traditional gliotransmitters such as D-serine, ATP, and glutamate. Mobilization of intracellular stores of Ca2+ occurs within a matter of seconds, but this novel Ca2+-independent lipid pathway in astrocytes could occur on a faster time scale and thus play a role in the rapid signaling processes involved in synaptic potentiation, attention, and neurovascular coupling.

neuroscience↗

bioRxiv2019

Human glial progenitor cells effectively remyelinate the demyelinated adult brain

Human glial progenitor cells (hGPCs) can completely myelinate the brains of congenitally hypomyelinated shiverer mice, rescuing the phenotype and extending or normalizing the lifespan of these mice. We asked if implanted hGPCs might be similarly able to broadly disperse and remyelinate the diffusely and/or multicentrically-demyelinated adult CNS. In particular, we asked if fetal hGPCs could effectively remyelinate both congenitally hypomyelinated adult axons, and axons acutely demyelinated in adulthood, using adult shiverer mice and cuprizone-demyelinated mice, respectively. We found that hGPCs broadly infiltrate the adult CNS after callosal injection, and robustly myelinate congenitally-unmyelinated axons in adult shiverer. Moreover, implanted hGPCs similarly remyelinated denuded axons after cuprizone demyelination, whether they were delivered prior to or after initial cuprizone demyelination. Extraction and FACS of hGPCs from cuprizone-demyelinated brains in which they had been resident, followed by RNA-seq of the isolated human hGPCs, revealed their activation of transcriptional programs indicating their initiation of oligodendrocyte differentiation and myelination. These data indicate the ability of transplanted hGPCs to disperse throughout the adult CNS, to myelinate dysmyelinated regions encountered during their parenchymal colonization, and to also be recruited as myelinating oligodendrocytes at later points in life, upon demyelination-associated demand.

neuroscience↗