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conferenceseries
.com
Volume 4
Toxicology: Open Access
ISSN: 2476-2067
Toxicology Congress 2018
March 12-14, 2018
March 12-14, 2018 Singapore
14
th
World Congress on
Toxicology and Pharmacology
Roles of
ATP7B
gene to maintain the copper-transporting ATPase in a HepG2 cell line against excess
copper toxicity
Shikha Agnihotry, Jaya Upadhayay, Pradeep K Shukla and Budhayash Gautam
Sam Higginbottom University of Agriculture, Technology and Sciences, India
W
ilson disease (WD) is an autosomal recessive disorder of copper
transport with a worldwide frequency of ~1 in 30000. Wilson’s disease
is characterized by chronic liver and neurological disease and also reported in
kidney. Hepatic copper levels vary among normal individuals and WD patients
depending upon on dietary copper intake and bioavailability, as well as genetic
factors. In this study we examined that abnormal copper accumulation in human
hepatocarcinoma (HepG2) cell line. Copper chloride (CuCl
2
) caused dose
dependent cell viability reduction of human hepatocarcinoma (HepG2) cell line
which was measured through MTT assay. We used different concentration of
CuCl
2
in their log doses but maximum cell viability reduction was recorded at 15
µg/ml. It also induces cell cycle arrest and DNA damage due to intracellular ROS
generation. CuCl
2
induces Ca
2+
release from endoplasmic reticulum (ER) and
leads to apoptotic cell death. It causes the up-regulation of WD stress marker
genes
ATP7B
and Cyp1A1, Cyp1A2 at transcription levels. The similar response
of
ATP7B
and Cyp1A1, Cyp1A2 proteins was recorded at translation levels. Heavy dietary intake of CuCl
2
induces mitochondria
and reduced the mitochondrial membrane potential analyzed through JC-1 staining. It further increases Bax/Bcl2 ratio and
promotes the release of cytochrome C, finally leads to caspase-dependent apoptosis. Up-regulation of APAF1 in CuCl
2
treated
cells supports the mitochondrial-mediated apoptotic cell death. The results support the involvement of ER and mitochondria
in ROS mediated CuCl
2
toxicity. Therefore, the heavy dietary intake of CuCl
2
in food products may be deleterious to users.
References
1. Brady A H, Stein H A, Turschner S, Toegel I, Mora R, Jennewein N, Efferth T, Eils R, Brady N R (2011) Artesunate activates
mitochondrial apoptosis in breast cancer cells via iron-catalyzed lysosomal reactive oxygen species production.
J. Biol.
Chem.
; 286: 6587–6601.
2. Kroemer G, Reed J C (2000) Mitochondrial control of cell death.
Nat. Med.
; 6: 513–519.
3. Hart E B, Steenbock H, Waddell J (1928) Iron nutrition. VII: Copper is a supplement to iron for hemoglobin building in
the rat.
The Journal of Biological Chemistry
; 77: 797–833.
Biography
Shikha Agnihotry has been working as Research Assistant at Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow of ICMR since 2013. She has
been involved in training biomedical research scholars in the field of bioinformatics and has also assisted as Research Assistant under an ICMR-funded project.
shikha25agnihotry@gmail.comShikha Agnihotry et al., Toxicol Open Access 2018, Volume 4
DOI: 10.4172/2476-2067-C1-006
Cu
Cu
DNA
NUCLEUS
ER
Brain
Liver
Wilsondisease
.Absorbedby
body
.Remainsin
body Copperfrom
food
.Coppersticks to
liver
.Causeshepatitis
andfailure
Liver
.Coppersticks to
brain
.Depression,
dementia
Brain
Cu
Tissue
cell
ATP7BGene
Defect/mutation in this gene to failmetabolized excessive copper resulting wilson disease
ATP7B
Gene
In-silicostudy
In-silicostudy
ROS
Figure-1:
Graphical abstract of copper toxicity