Wildfire smoke is a growing concern due to continually rising exposures and links to numerous adverse health effects. Lipids are essential regulators …

Henne and Prinz discuss the lipid droplet field and pervasive questions surrounding droplets and their roles in physiology and disease.

Organelles feature characteristic lipid compositions that lead to differences in membrane properties. In cells, membrane ordering and fluidity are commonly measured using the solvatochromic dye Laurdan, whose fluorescence is sensitive to lipid packing. As a general lipophilic dye, Laurdan stains all hydrophobic environments in cells; therefore, it is challenging to characterize membrane properties in specific organelles or assess their responses to pharmacological treatments in intact cells. Here, we describe the synthesis and application of Laurdan-derived probes that read out the membrane packing of individual cellular organelles. The set of organelle-targeted Laurdans (OTL) localizes to the ER, mitochondria, lysosomes, and Golgi compartments with high specificity while retaining the spectral resolution needed to detect biological changes in membrane ordering. We show that ratiometric imaging with OTLs can resolve membrane heterogeneity within organelles as well as changes in lipid packing resulting from inhibition of trafficking or bioenergetic processes. We apply these probes to characterize organelle-specific responses to saturated lipid stress. While the ER and lysosomal membrane fluidity is sensitive to exogenous saturated fatty acids, that of mitochondrial membranes is protected. We then use differences in ER membrane fluidity to sort populations of cells based on their fatty acid diet, highlighting the ability of organelle-localized solvatochromic probes to distinguish between cells based on their metabolic state. These results expand the repertoire of targeted membrane probes and demonstrate their application in interrogating lipid dysregulation.

Directional, non-vesicular lipid transport is responsible for fast, species-selective lipid sorting into organelle membranes.

This study shows that animal-based high-fat diets accelerate tumour growth and impair anti-tumour response to melanoma in obese mice, whereas plant-based high-fat diets do not.

Rao and Cai et al. perform a detailed metabolic comparison between primary tumours from patients and their matching xenografts, which identify conserved as well as divergent metabolic patterns.

The Scientist is excited to announce the winners of our 2025 science writing contest!

Rashan, Bartlett and colleagues show that mammalian 4-hydroxy fatty acids are primarily catabolized by ACAD10 and ACAD11 (atypical mitochondrial and peroxisomal acyl-CoA dehydrogenases, respectively) ...

Rashan, Bartlett and colleagues show that mammalian 4-hydroxy fatty acids are primarily catabolized by ACAD10 and ACAD11 (atypical mitochondrial and peroxisomal acyl-CoA dehydrogenases, respectively) ...

Here, Paul et al. show that APMAP is an ER-localized paraoxonase-like enzyme that suppresses lipid oxidation and redox stress at the ER network. APMAP loss leads to ER stress, redox disruption, phosph...