Hallmark Molecular and Pathological Features of POLG Disease are Recapitulated in Cerebral Organoids

In this research, a 3D brain organoid model is developed to study POLG-related encephalopathy, a mitochondrial disease stemming from POLG mutations. Induced pluripotent stem cells (iPSCs) derived from patients with these mutations is utilized to generate cortical organoids, which exhibited typical features of the diseases with POLG mutations, such as altered morphology, neuronal loss, and mitochondiral DNA (mtDNA) depletion. Significant dysregulation is also identified in pathways crucial for neuronal development and function, alongside upregulated NOTCH and JAK-STAT signaling pathways. Metformin treatment ameliorated many of these abnormalities, except for the persistent affliction of inhibitory dopamine-glutamate (DA GLU) neurons. This novel model effectively mirrors both the molecular and pathological attributes of diseases with POLG mutations, providing a valuable tool for mechanistic understanding and therapeutic screening for POLG-related disorders and other conditions characterized by compromised neuronal mtDNA maintenance and complex I deficiency. This research demonstrates that cerebral organoids derived from iPSCs of POLG mutation patients replicate essential aspects of POLG disease, including neuronal loss and mitochondrial dysfunction. Additionally, the study explores the therapeutic potential of metformin, revealing its efficacy in ameliorating organoid phenotypes, suggesting new avenues for treatment strategies in POLG-related disorders. image