51st Annual Meeting & ToxExpo - Society of Toxicology

Society of Toxicology 2012
Scientific
Symposia
The Toxicological Impact of Metals, Crude Oil, and
Chemical Dispersants from the Gulf of Mexico Oil
Crisis on Human and Wildlife Health
Wednesday, March 14, 9:00 AM to 11:45 AM
Chairperson(s): John Pierce Wise Sr., University of Southern Maine,
Ocean Alliance, Portland, ME, and Joe Griffitt, University of Southern
Mississippi, Hattiesburg, MS.
Sponsor:
Metals Specialty Section
Endorsed by:
Comparative and Veterinary Specialty Section
Mixtures Specialty Section
Toxicologic and Exploratory Pathology Specialty Section
The 2010 Gulf of Mexico oil crisis was the worst environmental pollution
disaster in US history. By the time the well was capped, more
than 200 million gallons of crude oil poured into the Gulf over an
87-day period. To combat the crisis, a marine toxicology strategy was
deployed to decrease the toxic potential of the crisis to inshore species
by increasing the toxic potential to offshore species. Thus, over two
million gallons of chemical dispersants were applied to the oil, which
prevented oil accumulation at the ocean surface and, instead, moved
it into the water column and onto the ocean floor. This approach
decreased the amount of surface oil reaching inshore waters and
beaches. However, it is unclear if it ultimately decreased toxicity to
inshore species because the acute and chronic toxicity of dispersants,
dispersed oil, and oil-related metals in the water column are
unknown. Also unknown are the toxic outcomes of this approach for
offshore species. During this session our panel of experts will present
and discuss some of the first studies to evaluate the impact of this toxicological
strategy considering the toxicity of crude oil, dispersants,
dispersed oil, and oil-related metals on benthic and pelagic species
using a combination of field and laboratory studies. Species presented
will span from microbes and invertebrates, to fish and whales with
some consideration of human health effects. Outcomes discussed will
range from simple survival studies to more subtle effects on reproduction
and DNA integrity.
• The Deepwater Horizon Disaster. Iain Kerr, University of Southern
Maine, Ocean Alliance, Lincoln, MA.
• Microbial Degradation of Oil and Gas Following the Macondo
Blowout. Samantha Joye, University of Georgia, Athens, GA.
• Assessing the Impact of Chemical Oil Spill Dispersants on
Corals. Carys Mitchelmore, University of Maryland Center for
Environmental Science, Solomons, MD.
• Effects of Dispersed Oil on Larval Sheepshead Minnows.
Joe Griffitt, University of Southern Mississippi, Hattiesburg, MS.
• Weathering and Dispersion of Crude Oil Alter Its Toxicity in the
Euryhaline Teleost, Fundulus grandis. Greg Mayer, Texas Tech
University, Lubbock, TX.
The Thematic Track information can be found on pages 8–9.
• The Gulf of Mexico Offshore Toxicology Study. John Pierce Wise
Sr., University of Southern Maine, Ocean Alliance, Portland, ME.
Innovations of Applied Toxicology (IAT) Session
Characterizing Toxic Modes of Action
and Pathways to Toxicity
New Visions in Toxicology: Lysosomes—Roles in
Disease, Toxicity, and Drug Development
Wednesday, March 14, 1:30 PM to 4:15 PM
Chairperson(s): Shuyan Lu, Pfizer, Inc., San Diego, CA, and James
M. Willard, US FDA, Silver Spring, MD.
Sponsor:
Mechanisms Specialty Section
Endorsed by:
Drug Discovery Toxicology Specialty Section
Lysosomes, first discovered by Dr. Christian de Duve more than
five decades ago, are membrane-enclosed compartments filled with
acid hydrolytic enzymes that digest macromolecules from the endocytic,
autophagic, and phagocytic membrane-trafficking pathways.
Lysosomes are involved in various physiological processes, including
cholesterol homeostasis, plasma membrane repair, bone and tissue
remodeling, and pathogen defense. Lysosomal malfunction as a
consequence of genetic deficiency of a lysosomal enzyme or membrane
protein can trigger lysosomal storage diseases with various clinical
abnormalities such as organomegaly and central nervous system
dysfunction. Recently, growing lines of evidence point to a critical
role of lysosomes in cell death. Leakage of lysosomal enzymes and
iron has been shown to result in mitochondria-mediated apoptosis.
Inducers of lysosomal membrane permeabilization include, but are
not limited to, oxidative stress, lipids, caspases, microtubule toxins,
and metals. A number of basic lipophilic compounds have been
shown to accumulate into acidic organelles, including lysosomes, in
a process known as lysosomotropism. Lysosomotropic agents include
structurally diverse chemicals that are used in clinical medicine such
as chloroquine, amiodarone, imipramine, tamoxifen, and imatinib. In
the past, phospholipidosis associated with drug lysosomal sequestration
has been investigated extensively and prevailing theory has been
that the phopholipidosis is primarily an adaptive response rather than
a toxic response. However, the relationship between physicochemical
properties of compounds, lysosomal accumulation, cellular damage,
impairment of membrane trafficking processes, including autophagy,
and especially how this is associated with various toxicological manifestations
has not been fully elucidated. The goal of this symposium
is to highlight the potential role of the lysosome in drug-induced
toxicity and recognize lysosome perturbation as a potential mechanism
for organ toxicity.
Thematic Session
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SOT’s 51 st Annual Meeting