Myofibrillar degeneration with diphtheria toxin Difteri toksini ile miyofibriler dejenerasyon


ÖZERMAN EDİS B., Bektaş M., Nurten R.

Turkish Journal of Biochemistry, cilt.45, sa.4, ss.351-357, 2020 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 45 Sayı: 4
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1515/tjb-2019-0109
  • Dergi Adı: Turkish Journal of Biochemistry
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, EMBASE, TR DİZİN (ULAKBİM)
  • Sayfa Sayıları: ss.351-357
  • Anahtar Kelimeler: Actin, Diphtheria toxin, FITC-conjugation, Myofibril, Myofilament, Ultrastructure
  • İstanbul Yeni Yüzyıl Üniversitesi Adresli: Hayır

Özet

Objectives: Cardiac damage in patient with diphtheritic myocarditis is reported as the leading cause of mortality. Diphtheria toxin (DTx) is a well-known bacterial toxin inducing various cytotoxic effects. Mainly, catalytic fragment inhibits protein synthesis, induces cytotoxicity, and depolymerizes actin filaments. In this study, we aimed to demonstrate the extent of myofibrillar damage under DTx treatment to porcine cardiac tissue samples. Methods: Tissue samples were incubated with DTx for 1-3 h in culture conditions. To analyze whole toxin (both fragments) distribution, conjugation of DTx with FITC was performed. Measurements were carried out with fluorescence spectrophotometer before and after dialysis. Immunofluorescence microscopy was used to show localization of DTx-FITC (15 nM) on cardiac tissue incubated for 2 h. Ultrastructural characterization of cardiac tissue samples treated with DTx (15 or 150 nM) was performed with transmission electron microscopy. Results: DTx exerts myofibrillar disorganization. Myofilament degeneration, mitochondrial damage, vacuolization, and abundant lipid droplets were determined with 150 nM of DTx treatment. Conclusions: This finding is an addition to depolymerization of actin filaments as a result of the DTx-actin interactions in in vitro conditions, indicating that myofilament damage can occur with DTx directly besides protein synthesis inhibition. Ultrastructural results support the importance of filamentous actin degeneration at diphtheritic myocarditis.