Polymorphism of hen egg white lysozyme amyloid fibrils influences the cytotoxicity in LLC-PK1 epithelial kidney cells.
The polymorphism of amyloid fibrils is potentially crucial as it may underlie the natural variability of amyloid diseases and could be important in developing a fuller understanding of the molecular basis of protein deposition disorders. This study examines morphological differences in lysozyme fibrils and the implications of these differences in terms of cytotoxicity. The structural characteristics of amyloid fibrils formed under two different experimental conditions (acidic and neutral) were evaluated using spectroscopic methods, atomic force microscopy and image analysis. Growth curves and apoptotic/necrotic assays were used to determine the cytotoxic effect of fibrils on the LLC-PK1 renal cells. The results reveal that both types of mature lysozyme amyloid fibrils are actively involved in the cytotoxic process, however each exhibit different levels of cytotoxicity. Fibrils formed at acidic pH affect cell growth in a dose-dependent manner, but a threshold-dependent inhibition of cell growth was observed in the case of lysozyme fibrils prepared at neutral pH. Experiments examining the mechanism of the cell death suggest that both types of mature lysozyme fibrils trigger late apoptosis/necrosis at different fibril concentrations. Our findings clearly indicate that the intrinsic differences between amyloid fibrils due to their polymorphism result in different degrees of cytotoxicity.
Department of Biophysics, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania.
Maria-Magdalena
MM
Mocanu
Department of Biophysics, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania.
Constanta
C
Ganea
Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Kosice, Slovakia.
Katarina
K
Siposova
Department of Biophysics, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania.
Alexandru
A
Filippi
Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Kosice, Slovakia.
Erna
E
Demjen
Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Kosice, Slovakia.
Jozef
J
Marek
Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Kosice, Slovakia; Department of Biochemistry, Faculty of Science, Safarik University, Kosice, Slovakia.
Zuzana
Z
Bednarikova
Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Kosice, Slovakia.
Andrea
A
Antosova
Department of Biophysics, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania.
Irina
I
Baran
Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Kosice, Slovakia; Department of Medical and Clinical Biochemistry and LABMED, Faculty of Medicine, Safarik University, Kosice, Slovakia. Electronic address: gazova@saske.sk.
Zuzana
Z
Gazova
D000682:Amyloid / Q000737:chemistry* / Q000633:toxicity*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D003603:Cytotoxins / Q000737:chemistry / Q000633:toxicity; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration; D007668:Kidney / Q000166:cytology*; D009113:Muramidase / Q000737:chemistry* / Q000633:toxicity*; D009336:Necrosis / Q000139:chemically induced; D055503:Protein Multimerization; D017433:Protein Structure, Secondary
D000682:Amyloid; D003603:Cytotoxins; C421864:hen egg lysozyme; D009113:Muramidase
Amyloid; Amyloid fibrils; Apoptosis; Lysozyme; Necrosis; Polymorphism