Analysis of apoptosis and DNA damage in bovine cumulus cells after exposure in vitro to different zinc concentrations

ANCHORDOQUY JM; PICCO SJ ; ANALÍA SEOANE; ANCHORDOQUY JP ; PONZINIBBIO MV; MATTIOLI GA; PERAL GARCÍA P; FURNUS CC

CELL BIOLOGY INTERNATIONAL

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Aberdeen (Portland Press Ltd.); Año: 2011 vol. 35 p. 593 - 597

1065-6995

The purpose of this study was to investigate the effect of zinc (Zn) concentration on cumuluscells (CC) during in vitro maturation. For this purpose, DNA integrity of CC by addition ofdifferent Zn concentrations 0 (Control); 0.7 μg/mL (Zn1); 1.1 μg/mL (Zn2) and 1.5 μg/mL (Zn3)to culture medium was evaluated by comet assay. In addition, early apoptosis was analyzed byannexin staining assay. Cumulus cells treated with Zn showed a significant decrease in the DNAdamage in a dose dependent manner. Comet assay analyzed for Tail Moment was significantlyhigher in cells cultured without Zn (Control, p < 0.01) respect to cells treated with Zn (Control:5.24 ±16.05; Zn1: 1.13 ±5.31; Zn2: 0.10 ±0.36; Zn3: 0.017 ±0.06). All treatments werestatistically different from the Control (p=0.014 for Zn1; p< 0.01 for Zn2 and Zn3). Thefrequency of apoptotic cells was higher in the Control group (Control: 0.142 ±0.07; Zn1: 0.109 ±0.0328; Zn2:0.102 ± 0.013; Zn3: 0.0577 ± 0.019). Statistical differences were found betweenControl and Zn1 (p= 0.0308), Control and Zn2 (p= 0.0077), Control and Zn3 (p< 0.0001), Zn1and Zn3 (p< 0.001) and Zn2 and Zn3 (p= 0.0004). No differences were found between Zn1 andZn2. In conclusion, low Zn concentrations increase DNA damage and apoptosis in CC cultured invitro. However, adequate Zn concentrations ?protect? the integrity of DNA molecule anddiminish the percentage of apoptotic CC.