Altered autophagy in KANSL1 haploinsufficient iPSC-derived astrocytes

Koolen-de Vries syndrome (KdVS) is a rare genetic disorder marked by intellectual disability and epilepsy, resulting from haploinsufficiency of KANSL1. This gene encodes a scaffolding protein within the non-specific lethal (NSL) complex which is crucial for histone modifications. The NSL complex regulates the expression of housekeeping, DNA repair, and autophagy genes. Autophagy, a pivotal process delivering cytoplasmic material to the lysosome for degradation, plays a key role in brain development and homeostasis maintenance; defects in autophagy have been linked to neurodevelopmental disorders (Lewerissa, Nadif Kasri, and Linda, 2024). Our lab previously showed increased oxidative stress-mediated autophagosome accumulation and reduced lysosomal function in KANSL1-deficient neurons, leading to diminished synaptic density and impaired neuronal networks (Linda et al., 2022). Cultures included healthy rodent astrocytes for neuron maturation and synaptogenesis. Astrocytes, involved in various processes, can affect neuronal viability when autophagy is decreased. However, reciprocal autophagy effects between astrocytes and neurons in influencing neuronal network formation remain elusive. As a first step, we will investigate autophagy in human astrocytes by using a newly developed iPSC differentiation protocol. Employing qPCR, western blot, and immunofluorescence, we aim to elucidate the impact of KANSL1 haploinsufficiency in astrocytes. Preliminary results indicate heightened autophagosome and lysosomal activity, supported by increased LC3 and LAMP1 signaling in immunofluorescence and western blot analyses. Additionally, RNAseq reveals differential gene expression related to autophagy, lysosomes, and mitophagy, particularly during early astrocyte differentiation. Further experiments are crucial for validating these intriguing findings.