Apoptotic-like phenotype triggered by hydrogen peroxide and amphotericin B in the fungus Rhizopus arrhizus.

ABSTRACT

Rhizopus is the most common genus of invasive mucormycosis, whose prognosis and outcome was not improved over the past decades. We studied the apoptotic-like phenotype in Rhizopus arrhizus exposed to hydrogen peroxide (H2 O2 ) and amphotericin B (AMB). The strain provided by Fungal Genetic Stock centre was studied about the apoptotic-like phenotype treated with different concentrations of H2 O2 and AMB, and then analyzed by fluorescent microscopy (observed by Annexin-V/FITC and TUNEL staining), flow cytometry (stained with DHR123/PI), and DNA agarose gel electrophores. When R. arrhizus was treated with H2 O2 and AMB, there was a loss of viability associated with different phenotype of apoptosis makers. Membrane externalization of phosphatidylserine (PS) on the cell surface, DNA fragmentation, chromatin condensation can be induced and observed obviously by Annexin-V/FITC, DAPI and TUNEL staining. DNA smear not DNA ladder was also visible in R. arrhizus. Flowcytometry of R. arrhizus cells revealed not only the increase of apoptosis cell stained with DHR123 under the nonfungicida doses but dead cells stained with PI under the fungicida concentrations.This study indicated that both H2 O2 and AMB could induce the apoptotic-like phenotype in R. arrhizus.