Mitochondrial Membrane Fats Hold Steady as Brain Cells Transform

Deep inside every developing brain cell, its mitochondria are quietly holding their ground while everything around them changes. A new study published in BMC Biology by researchers at Kasturba Medical College, Manipal Academy of Higher Education, has mapped, for the first time in detail, how the lipid composition of both whole cells and their mitochondria shifts as human pluripotent stem cells mature into neural stem cells and then into neurons. The striking finding is that while the cellular lipidome undergoes dramatic remodeling during early neurodevelopment, the mitochondrial lipidome remains remarkably stable at the level of major lipid classes.

The team, led by corresponding author Dinesh Upadhya of the Department of Anatomy, used human pluripotent stem cells, or PSCs, as their starting material. These cells were differentiated into neural stem cells and then into neurons, creating a controlled developmental trajectory that mirrors the earliest chapters of human brain formation. At each stage, the researchers isolated both whole-cell lipid extracts and purified mitochondrial fractions, verifying their purity with marker proteins such as ATP5A1 for mitochondria, GRP94 for the endoplasmic reticulum, and CD63 for other membranes. They then employed liquid chromatography coupled with tandem mass spectrometry, a sensitive lipidomics workflow, to quantify hundreds of individual lipid species across the glycerolipid and glycerophospholipid families.

The first broad observation was a gradual increase in relative lipid content as cells progressed from pluripotency toward neuronal identity, a trend seen in parallel at both the cellular and mitochondrial levels. Remarkably, the ratio of unsaturated to total lipids remained relatively stable across these transitions, suggesting that developing cells maintain a consistent degree of membrane fluidity even as they accumulate more lipid material. This constancy of unsaturation may reflect an underlying homeostatic program that protects membrane properties during the intense structural reorganization that accompanies neural differentiation.

Beneath this apparent calm, however, the cellular lipidome was anything but static. Relative levels of diacylglycerols, short-lived signaling lipids best known for activating protein kinase C pathways, rose steadily and significantly as PSCs became neural stem cells and then neurons. At the same time, relative levels of triacylglycerols, the cells’ storage fats, declined over the same trajectory. This reciprocal shift implies that developing neural cells actively break down their energy reserves and convert them into signaling-competent intermediates, possibly to fuel the demanding processes of proliferation, migration, and neurite extension that define neurodevelopment.

Among the glycerophospholipids, one change stood out with particular force: phosphatidylcholine, the most abundant phospholipid in most mammalian membranes, showed a drastic increase in relative abundance in mature neurons compared with pluripotent stem cells and neural stem cells. This enrichment likely supports the enormous expansion of membrane surface area required to build axons and dendrites, as well as the specialized electrical properties that neurons must acquire. In parallel, the ratio of phosphatidylcholine to phosphatidylethanolamine, two structural phospholipids whose balance influences membrane curvature and integrity, increased in both whole cells and mitochondria across the developmental sequence.

Yet when the researchers stepped back to compare the major lipid classes as a whole, a clear contrast emerged. The cellular lipid composition shifted significantly at every transition, while mitochondria maintained a relatively stable distribution of their principal lipids, including the glycerolipids and glycerophospholipids that form the inner and outer mitochondrial membranes. This stability makes functional sense: mitochondria depend on a tightly controlled lipid environment, particularly cardiolipin-rich inner membranes, to sustain oxidative phosphorylation, calcium handling, and the fission and fusion dynamics that developing cells rely on. Even as the cell around them reinvents itself, mitochondria appear to preserve their core lipid architecture.

Stability at the class level, however, did not mean molecular stagnation. More granular, species-level analyses of the mitochondrial lipidome revealed significant remodeling among individual lipid species, with differentially abundant molecular forms identified between PSCs, neural stem cells, and neurons through fold-change and univariate statistical comparisons. In other words, mitochondria fine-tune the precise fatty-acyl chains attached to their lipids while keeping the overall lipid class proportions constant, a strategy that could adjust membrane biophysics without disrupting core mitochondrial functions.

The study fills a genuine gap in developmental biology. Although mitochondria are known to be central players in neurodevelopment, powering the proliferation, differentiation, migration, and maturation of neural cells, the dynamics of their lipid composition during these critical windows had remained unexplored. Lipids are not passive structural fillers; they regulate membrane enzymes, transporters, signaling cascades, and the physical properties that determine whether membranes bend, fuse, or hold firm. Documenting their normal trajectory provides an essential reference point for understanding when development goes awry.

The clinical implications of this baseline dataset are considerable. Because many neurodevelopmental disorders, from autism spectrum conditions to intellectual disability syndromes, are now studied using patient-derived induced pluripotent stem cells, the lipid profiles established here offer a benchmark against which disease-associated lipid perturbations can be measured. If a patient’s neural lineage shows abnormal diacylglycerol accumulation, distorted phosphatidylcholine levels, or destabilized mitochondrial lipid proportions, researchers will now have the normal developmental template to compare against, potentially revealing metabolic vulnerabilities that underlie neurological disease.

The work also raises intriguing questions for future research. What mechanisms anchor the mitochondrial lipidome in place during development, and how do mitochondria communicate their lipid needs to the endoplasmic reticulum, the major site of phospholipid synthesis? Do specific lipid species emerging during the stem-cell-to-neuron transition serve as developmental signals in their own right? As lipidomics technology becomes faster and more accessible, the mitochondrial lipid landscape of the developing human brain, long an invisible dimension of neurobiology, is finally coming into focus, one fatty acid chain at a time.

Subject of Research: Lipidomic changes in cells and mitochondria during early human neurodevelopment

Article Title: Mitochondrial lipidome exhibits relatively higher stability than cell lipidome during early neurodevelopment

Article References: Hegde, S., Chandran, D., Tripathy, D. K., Ramesh, A. I., Prabhu, K., & Upadhya, D. (2026). Mitochondrial lipidome exhibits relatively higher stability than cell lipidome during early neurodevelopment. BMC Biology. https://doi.org/10.1186/s12915-026-02726-0

Image Credits: AI Generated

DOI: 10.1186/s12915-026-02726-0

Keywords: mitochondria, lipidomics, neurodevelopment, neural stem cells, pluripotent stem cells, phosphatidylcholine, diacylglycerols, triacylglycerols, neurons, BMC Biology, Mitochondrial, lipidome