Lipidomics Reveals a Tissue-Specific Fingerprint

TLDR

Lipids form membranes, signal, and store energy, and diverse molecular species exist across membranes and tissues, yet their distribution remains unclear. The study aims to quantify lipid abundance across seven rat tissues using mass spectrometry, detecting 652 lipid species across major lipid classes. Mass spectrometry was used to detect and quantify 652 lipid species across seven rat tissues, covering glycerolipid, glycerophospholipid, fatty acyl, sphingolipid, sterol, and prenol categories. The analysis revealed tissue‑specific lipid fingerprints, with glycerophospholipids most abundant overall, sphingolipids concentrated in renal cortex, sterols mainly in liver and kidney, white adipose tissues rich in glycerolipids, acylcarnitines in skeletal muscle, and higher ubiquinone in heart.

Abstract

In biological systems lipids generate membranes and have a key role in cell signaling and energy storage. Therefore, there is a wide diversity of molecular lipid expressed at the compositional level in cell membranes and organelles, as well as in tissues, whose lipid distribution remains unclear. Here, we report a mass spectrometry study of lipid abundance across 7 rat tissues, detecting and quantifying 652 lipid molecular species from the glycerolipid, glycerophospholipid, fatty acyl, sphingolipid, sterol lipid and prenol lipid categories. Our results demonstrate that every tissue analyzed presents a specific lipid distribution and concentration. Thus, glycerophospholipids are the most abundant tissue lipid, they share a similar tissue distribution but differ in particular lipid species between tissues. Sphingolipids are more concentrated in the renal cortex and sterol lipids can be found mainly in both liver and kidney. Both types of white adipose tissue, visceral and subcutaneous, are rich in glycerolipids but differing the amount. Acylcarnitines are mainly in the skeletal muscle, gluteus and soleus, while heart presents higher levels of ubiquinone than other tissues. The present study demonstrates the existence of a rat tissue-specific fingerprint.