ANKRD1 Gene Therapy Improves Memory Function in Aged Mice
Neurogenesis is the creation of new neurons from stem cell populations, followed by the integration of these newly created cells into existing neural networks. Neurogenesis is required for memory and learning to take place in the adult brain, and is thought to provide an important contribution to what limited capacity for regeneration exists in brain tissue. If researchers could induce a greater degree of neurogenesis, this could be a path to greater repair of an injured brain, and restoration of lost function in an aged brain.
This high level view of neurogenesis skates over a great deal of complexity, much of which has yet to be mapped. For example, which cell populations are responsible for generating new neurons? What are their regulating mechanisms? Why does activity decline with age? Neurogenesis does not emerge from one single cell population; it isn't just neural stem cells, and even that label covers a great many distinct varieties and locations of cell within the brain. Some sources of neurons are even found outside the brain - nearby, but not within brain tissue.
Today's open access paper gives a sense of the work needed to pin down just one of the many cell populations that can act as sources of new neurons for the adult brain. Here, the cells are resident in bone marrow of the skull. The authors summarize their findings to present both the distinct subpopulation of mesenchymal stem cells that generates neurons and a way to beneficially manipulate its activity via increased expression of the ANKRD1 gene. A viral gene therapy delivered systemically, but where the ANKRD1 expression is constrained by promoter, increases neurogenesis in aged mice to improve cognitive function.
ANKRD1 sustains a neurogenic BMSC niche and counters cognitive aging
Craniofacial bone marrow mesenchymal stromal cells (BMSCs) derived from neural crest stem cells (NCSCs), which represent a transient embryonic progenitor population endowed with diverse lineages, including peripheral neurons and glia. Emerging evidence suggests adult BMSCs retain traces of their NCSCs heritage, exhibiting latent neurogenic plasticity that could be harnessed for neural repair. Despite progress in characterizing BMSCs multipotency, the transcriptional circuits preserving their neural competence during aging and the mechanisms by which they deteriorate remain unresolved.
In this study, through scRNA-seq of human BMSCs, we discovered a discrete subpopulation exhibiting molecular signatures of neurogenic potential. Gene enrichment analysis identified ANKRD1 as a top-scoring candidate, and subsequent validation studies confirmed its role as a key regulator of this neurogenic phenotype. We propose that ANKRD1 may sustain neurogenic competence in undifferentiated BMSCs, a capacity that is progressively eroded by aging or differentiation-associated transcriptional reprogramming. Mechanistically, protein-DNA interaction profiling revealed that ANKRD1 directly engages with enhancer elements of SOX2 and NESTIN, thereby preserving their expression and reinforcing neural-lineage characteristics.
Critically, neuron-targeted ANKRD1 delivery rescues spatial memory deficits in aged mice. These findings establish ANKRD1 as a therapeutically tractable regulator that sustains neurogenic chromatin reservoirs to support neurocognitive resilience, opening avenues to counter cognitive aging.