Detection of autophagy in tissue by standard immunohistochemistry: possibilities and limitations.
Transmission electron microscopy (TEM) is currently the standard method to monitor autophagy in tissue. Because TEM is labor intensive, we recently questioned whether marker proteins could be found for unambiguous detection of autophagy in tissue using standard immunohistochemical techniques. Our findings indicated that the identification of autophagy-specific biomarkers for tissue is highly compromised due to lack of differential gene expression. In this respect, TEM remains an indispensable technique for evaluation of autophagy in situ. Nevertheless, immunohistochemical staining of microtubule-associated protein 1 light chain 3 (LC3) appeared to be a valuable technique to detect autophagosome formation in tissue but only when this protein is overexpressed, e.g., in GFP-LC3 transgenic animals. Furthermore, demonstration of granular cytoplasmic ubiquitin inclusions by immunohistochemistry may be an attractive technique to measure autophagic cell degeneration in some human pathologies such as neurodegenerative diseases, heart failure and atherosclerosis.
Martinet
Wim
W
Division of Pharmacology, University of Antwerp, Wilrijk, Belgium. wim.martinet@ua.ac.be
De Meyer
Guido R Y
GR
Andries
Luc
L
Herman
Arnold G
AG
Kockx
Mark M
MM
D000818:Animals; D001343:Autophagy; D015415:Biomarkers / Q000032:analysis*; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D051379:Mice; D008822:Mice, Transgenic; D008869:Microtubule-Associated Proteins / Q000032:analysis / Q000235:genetics; D010588:Phagosomes / Q000737:chemistry / Q000378:metabolism; D012680:Sensitivity and Specificity; D025801:Ubiquitin / Q000032:analysis
D015415:Biomarkers; C480860:Map1lc3b protein, mouse; D008869:Microtubule-Associated Proteins; D025801:Ubiquitin; D049452:Green Fluorescent Proteins