Gleichman, A. J. | bioRxiv Science

bioRxiv2026

Astrocytic chordin-like 1 (Chrdl1) is re-engaged early after ischemic stroke to regulate region-dependent GluA2 levels and neuronal vulnerability

Neuronal vulnerability to ischemic stroke varies markedly across brain regions, yet the mechanisms underlying this selective susceptibility remain poorly understood. Here, we show that the developmental astrocytic protein Chordin-like 1 (Chrdl1) is repurposed after ischemic injury to regulate neuronal vulnerability. Chrdl1 expression stabilizes GluA2-containing AMPA receptors, limits delayed apoptotic neuronal death, and preserves hippocampal function early after focal ischemic stroke, whereas sustained Chrdl1 expression does not improve long-term recovery. These findings identify an unexpected neuroprotective role for Chrdl1 during acute ischemia that contrasts with its previously described function as a limiter of synaptic plasticity during recovery. Our work reveals that developmental astrocyte-derived signaling can be redeployed after brain injury, with distinct functions depending on the stage of stroke and region-dependent endogenous expression that together determine whether a conserved neuroprotective mechanism is engaged after ischemic stroke.

neuroscience↗

bioRxiv2023

A toolbox of astrocyte-specific, serotype-independent adeno-associated viral vectors using microRNA targeting sequences.

Astrocytes, one of the most prevalent cell types in the central nervous system (CNS), are critically involved in neural function in both health and disease. Genetically manipulating astrocytes is an essential tool in understanding and affecting their roles. Adeno-associated viruses (AAVs) enable rapid genetic manipulation; however, astrocyte specificity of AAVs can be limited, with high off-target expression in neurons and sparsely in endothelial cells. Here, we report the development of a cassette of four copies of six miRNA targeting sequences (4x6T) which triggers transgene degradation specifically in neurons and endothelial cells. When used in combination with the GfaABC1D promoter, 4x6T increases astrocytic specificity of Cre with a viral reporter from <50% to >99% in multiple serotypes in mice, and confers astrocyte specificity in two inducible forms of Cre; Dre; and reporters. We also present empty vectors to add 4x6T to other cargo, independently and in Cre/Dre-dependent forms. This toolbox of AAVs provides a way to rapidly manipulate astrocytes throughout the CNS, is compatible with different AAV serotypes, and demonstrates the efficacy of using multiplexed miRNA targeting sequences to decrease expression in multiple off-target cell populations simultaneously.

neuroscience↗