Proteome architecture of human-induced pluripotent stem cell-derived three-dimensional organoids as a tool for early diagnosis of neuronal disorders

Background and objectives: Induced pluripotent stem cells (iPSCs) derived three-dimensional (3D) model for rare neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS) is emerging as a novel alternative to human diseased tissue to explore the disease etiology and potential drug discovery. In the interest of the same, we have generated a TDP-43-mutated human iPSCs (hiPSCs) derived 3D organoid model of ALS disease. The high-resolution mass spectrometry (MS)-based proteomic approach is used to explore the differential mechanism under disease conditions and the suitability of a 3D model to study the disease.

Materials and methods: The hiPSCs cell line was procured from a commercial source, grown, and characterized following standard protocols. The mutation in hiPSCs was accomplished using CRISPR/Cas-9 technology and predesigned gRNA. The two groups of organoids were produced by normal and mutated hiPSCs and subjected to the whole proteomic profiling by high-resolution MS in two biological replicates with three technical replicas of each.

Results: The proteomic analysis of normal and mutated organoids revealed the proteins associated with pathways of neurodegenerative disorders, proteasomes, autophagy, and hypoxia-inducible factor-1 signaling. Differential proteomic analysis revealed that the mutation in TDP-43 gene caused proteomic deregulation, which impaired protein quality mechanisms. Furthermore, this impairment may contribute to the generation of stress conditions that may ultimately lead to the development of ALS pathology.

Conclusion: The developed 3D model represents the majority of candidate proteins and associated biological mechanisms altered in ALS disease. The study also offers novel protein targets that may uncloud the precise disease pathological mechanism and be considered for future diagnostic and therapeutic purposes for various neurodegenerative disorders.