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Biology subjects

Kuuluvainen, E.

Publications and source records attributed to Kuuluvainen, E..

2 recordsLinked to original sources

Metabolic commitment to human motor neurons is characterized by mitochondrial depletion and pyruvate rewiring

Mitochondrial remodelling is a key feature of neurogenesis in cortical and hippocampal neuronal lineages, yet the temporal control of organellar homeostasis in developing human motor neurons remains poorly understood. Here, we generated a high-resolution temporal resource integrating proteomics, metabolomics, and mitochondrial characterization across human iPSC-to-motor neuron differentiation. This analysis revealed prolonged mitochondrial depletion during early neurogenesis, characterized by reduced mitochondrial content, mitochondrial fragmentation, and lysosome-dependent turnover. This state persisted throughout the neural progenitor stage and was followed by recovery of mitochondrial content during neuronal maturation. During this transition, pyruvate utilization shifted from pyruvate carboxylation towards pyruvate dehydrogenase-dependent oxidation. Pharmacological manipulation of pyruvate partitioning demonstrated that this metabolic switch is required for human neuronal differentiation. Our findings establish a temporal framework for the metabolic control of human motor neuron differentiation and reveal a progenitor-specific state linking mitochondrial depletion to pyruvate metabolism.

cell biology↗

Functional, metabolic and transcriptional maturation of stem cell derived beta cells

Transplantation of pancreatic islet cells derived from human pluripotent stem cells is a promising treatment for diabetes. Despite progress in stem cell-derived islet (SC-islet) generation, detailed characterization of their functional properties has not been conducted. Here, we generated functionally mature SC-islets using an optimized protocol and comprehensively benchmarked them against primary adult islets. Biphasic glucose stimulated insulin secretion developed during in vitro maturation, associated with cytoarchitectural reorganization and increased alpha cells. Electrophysiology and exocytosis of SC-islets were comparable to adult islets. Glucose-responsive insulin secretion was achieved despite differences in glycolytic and mitochondrial glucose metabolism. Single-cell transcriptomics of SC-islets in vitro and throughout 6 months of murine engraftment revealed a continuous maturation trajectory culminating in a transcriptional landscape closely resembling that of primary islets. Our thorough evaluation of SC-islet maturation highlights their advanced degree of functionality and supports their use in further efforts to understand and combat diabetes.

developmental biology↗