Characterization of pulmonary protein profiles in response to zinc oxide nanoparticles in mice: a 24-hour and 28-day follow-up study

Chih-Hong Pan,1,2,* Kai-Jen Chuang,3,4,* Jen-Kun Chen,5 Ta-Chih Hsiao,6 Ching-Huang Lai,2 Tim P Jones,7 Kelly A BéruBé,8 Gui-Bing Hong,9 Kin-Fai Ho,10,11 Hsiao-Chi Chuang12,13 1Institute of Occupational Safety and Health, Council of Labor Affairs, Executive Yuan, 2School of Public Health, National Defense Medical Center, 3School of Public Health, College of Public Health and Nutrition, 4Department of Public Health, School of Medicine, College of Medicine, Taipei Medical University, Taipei, 5Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Miaoli, 6Graduate Institute of Environmental Engineering, National Central University, Taoyuan, Taiwan; 7School of Earth and Ocean Sciences, 8School of Biosciences, Cardiff University, Cardiff, Wales, UK; 9Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, Taiwan; 10Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, People’s Republic of China; 11Shenzhen Municipal Key Laboratory for Health Risk Analysis, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, People’s Republic of China; 12School of Respiratory Therapy, College of Medicine, 13Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan *These authors contributed equally to this work Abstract: Although zinc oxide nanoparticles (ZnONPs) are recognized to cause systemic disorders, little is known about the mechanisms that underlie the time-dependent differences that occur after exposure. The objective of this study was to investigate the mechanistic differences at 24 hours and 28 days after the exposure of BALB/c mice to ZnONPs via intratracheal instillation. An isobaric tag for the relative and absolute quantitation coupled with liquid chromatography/tandem mass spectrometry was used to identify the differential protein expression, biological processes, molecular functions, and pathways. A total of 18 and 14 proteins displayed significant changes in the lung tissues at 24 hours and 28 days after exposure, respectively, with the most striking changes being observed for S100-A9 protein. Metabolic processes and catalytic activity were the main biological processes and molecular functions, respectively, in the responses at the 24-hour and 28-day follow-up times. The glycolysis/gluconeogenesis pathway was continuously downregulated from 24 hours to 28 days, whereas detoxification pathways were activated at the 28-day time-point after exposure. A comprehensive understanding of the potential time-dependent effects of exposure to ZnONPs was provided, which highlights the metabolic mechanisms that may be important in the responses to ZnONP. Keywords: glycolysis, iTRAQ, metabolism, nanoparticles, S100-A

Migration redefined? Seasonality, movements and group composition of humpback whales Megaptera novaeangliae

The migration of Southern Hemisphere humpback whales between their feeding and breeding areas has thus far been considered a highly predictable and seasonal event. However, previous observations on the humpbacks that pass through the near-shore waters of the west coast of South Africa have revealed deviations from the behaviour and seasonality expected during a typical migration. This “anomaly” is hypothesised to be associated with prey availability in the region. Shore-based observations between July 2001 and February 2003 from North Head, Saldanha Bay yielded relative abundances that again did not support a classical migration pattern, with the highest sighting rates from mid-spring through summer. Movement parameters (actual swimming speed, direction and linearity) of humpback groups tracked by theodolite showed mid-spring to be a turning point in their behaviour, after which we observed a significant reduction in actual swimming speed, an increase in ‘non11 directional’ movement, and a distribution further from shore than in other seasons. Additional data on group composition and sex collected between 1993 and 2008, showed a significantly female-biased sex ratio during mid-spring, the first such recorded for any region. Direct observation of feeding on crustacean prey during spring and summer months further supports the notion that humpbacks may have more flexible foraging habits than previously appreciated, and that the Southern Benguela upwelling region may function as an important feeding area for these whales.The fieldwork at Saldanha was supported by the National Research Foundation, South Africa (Grant number 2047517), and in 2002/03 also by the Earthwatch Institute, the Mazda Wildlife Fund (through the provision of a field vehicle), and SASOL (through the donation of two four-stroke engines). PADI Project AWARE (UK) provided funding for refurbishing the lookout. JB gratefully received a grant-in-aid from the Society for Marine Mammalogy and University of Pretoria post-graduate bursaries (2001-2003).http://www.tandf.co.uk/journals/TAM