Identification of GM3 as a marker of therapy-resistant periradicular lesions.

The purpose of this study was to analyze the profile of glycosphingolipids (GSLs) in periradicular lesions refractory to endodontic treatment. Sixteen periapical lesions were removed surgically from patients (experimental group) and compared with 10 samples of periodontal ligament removed from extracted intact third molars (control group). After the GSLs extraction and purification procedures were performed the neutral and acidic GSL fractions were analyzed by high-performance thin-layer chromatography and quantified by densitometry. Data reported herein show that: (i) tissues in the experimental group presented about twice as much GSLs as the control group; (ii) lesion tissues express lactoneotetraosylceramide, and lactofucopentaosyl (IV) ceramide, whereas these neutral GSLs are absent in normal tissues; and (iii) normal tissues express GT1b, whereas lesions cells do not express this ganglioside. In contrast lesion tissues express GM3, which is conspicuously absent in normal tissues.