Age-related Microglial Phenotype Characterized by Lipid and Iron Contents DOJINDO LABORATORIES

Latest Science Note
Dojindo Science Note [July 5, 2023]　　

Scientists have unveiled that in comparison to young mice, one-third of old microglia show Lipofustin-related autofluorescence (AF), characterized by profound changes in lipid and iron content, phagocytic activity, and oxidative stress. Pharmacological removal of microglia in older mice successfully eliminated AF-microglia, following the repopulation of new functional microglia leads to an improvement in age-related neurological impairments and reduces neurodegeneration after traumatic brain injury. Learn more about how the authors phenotyped AF-microglia using Lipi-Blue* for Lipid droplet labeling, and FerroOrange* for iron labeling. (Please refer to Fig. 1E, 5F, 9E for FerrOrange, Fig. 5D, 7E, for Lipi-Blue)

Brain injury accelerates the onset of a reversible age-related microglial phenotype associated with inflammatory neurodegeneration Click here for the original article: Rodney M Ritzel, et. al., Sci Adv (2023)

Point of Interest
- Lipofuscin accumulates in the brain's old microglia characterized by profound changes in lipid and iron content, phagocytosis, and oxidative stress.
- Increased phagocytic activity, lysosomal burden, and lipid accumulation in microglia are chronically driven by phagocyte-mediated oxidative stress.
- Pharmacological removal of lipofuscin-laden microglia in older mice leads to an improvement in age-related neurological impairments.

Related Techniques

Lipid droplets detection

Lipi-Blue / Green / Red / Deep Red

Intracellular ferrous ion (Fe²⁺) detection

FerroOrange

Mitochondria ferrous ion (Fe²⁺) detection

Mito-FerroGreen

Lysosomal function assay

Lysosomal Acidic pH Detection Kit-Green/Deep Red NEW

Lysosomal Acidic pH Detection Kit-Green/Red

Cellular senescence detection (Live cell imaging or FCM)

Cellular Senescence Detection Kit

Cellular senescence detection (Plate reader)

Cellular Senescence Plate Assay Kit

Mitochondrial superoxide detection

MitoBright ROS Deep Red - Mitochondrial Superoxide Detection

Total ROS detection

Highly sensitive DCFH-DA or Photo-oxidation Resistant DCFH-DA

Related Applications

Measurement of intracellular iron changes and lysosomal pH changes

Relationship between intracellular iron and lysosome function.

In neurodegenerative diseases, the relationship between lysosomal function and iron has attracted attention, and it has been reported* that lysosomal neutralization prevents the breakdown of iron stores (Transferrin or Ferritin), resulting in a decrease in intracellular iron. Lysosomal pH changes and intracellular iron changes in the same sample were detected using SH-SY5Y cells supplemented with lysosomal acidification inhibitor (Bafilomycin A1) or iron chelator (Deferipron (DFP)). (Lysosomal pH: this kit, Intracellular iron: FerroOrange The results showed that the addition of Bafilomycin A1 decreased the fluorescence of FerroOrange, confirming the decrease in intracellular iron. The fluorescence of LysoPrime DeepRed remained almost unchanged, while the fluorescence of pHLys Green decreased due to lysosomal neutralization. These results suggest that there is a relationship between changes in intracellular iron and lysosome function.

Reference: Ross A Weber, et. al., Mol Cell., 2020, 77(3), 645-655.

Products in Use
- FerroOrange
- Lysosomal Acidic pH Detection Kit-Green/Deep Red