Effects of microinjection of synthetic Bcl-2 domain peptides on apoptosis of renal tubular epithelial cells.
Bcl-2 protein family members are among the key regulators of the apoptosis effector phase. Therefore, we investigated the ability of synthetic peptides derived from proteins of the Bcl-2 family, namely, the NH2-terminal region of Bcl-2 (Bcl2_syn), a central domain of Bax (Bax_syn), and a central domain of Bak (Bak_syn) to interfere with the apoptotic process in LLC-PK1 cells. Apoptosis was induced by tacrolimus or lipopolysaccharide treatment, and microinjection of Bcl2_syn into stimulated LLC-PK1 cells significantly reduced the percentage of apoptotic cells detected within 4 h after the treatment. Microinjection of Bax_syn or Bax_syn, in contrast, induced apoptosis in otherwise untreated LLC-PK1 cells during the same period of time. A random sequence control peptide (Control_syn), which served as a negative control, as well as FITC-labeled dextran, which was coinjected in all experiments for visualization, were ineffective in either preventing or inducing apoptosis. These results suggest that synthetic peptides mimicking the functional domains of proteins of the Bcl-2 family are capable of regulating apoptosis when microinjected into LLC-PK1 cells in vivo. Analogs to these regulatory peptides could therefore provide valuable lead compounds in the therapeutical context.
Peherstorfer
Elisabeth
E
Division of Nephrology and Dialysis, Department of Internal Medicine III, University of Vienna, A-1090 Vienna, Austria.
Mayer
Bernd
B
Boehm
Stefan
S
Lukas
Arno
A
Hauser
Peter
P
Mayer
Gert
G
Oberbauer
Rainer
R
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D003574:Cytochrome c Group / Q000494:pharmacology; D004563:Electrochemistry; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007687:Kidney Tubules, Proximal / Q000166:cytology*; D018374:LLC-PK1 Cells; D008070:Lipopolysaccharides / Q000494:pharmacology; D016393:Lymphoma, B-Cell / Q000503:physiopathology; D008565:Membrane Proteins / Q000494:pharmacology; D008845:Microinjections; D010446:Peptide Fragments / Q000494:pharmacology; D017433:Protein Structure, Secondary; D011518:Proto-Oncogene Proteins / Q000494:pharmacology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000737:chemistry* / Q000494:pharmacology*; D013552:Swine; D016559:Tacrolimus / Q000494:pharmacology; D050998:bcl-2 Homologous Antagonist-Killer Protein; D051028:bcl-2-Associated X Protein
C494772:BAK1 protein, human; C494826:BAX protein, human; D003574:Cytochrome c Group; D007166:Immunosuppressive Agents; D008070:Lipopolysaccharides; D008565:Membrane Proteins; D010446:Peptide Fragments; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D050998:bcl-2 Homologous Antagonist-Killer Protein; D051028:bcl-2-Associated X Protein; D016559:Tacrolimus