Enhanced morphological transformation of human lung epithelial cells by continuous exposure to cellulose nanocrystals

Cellulose nanocrystals (CNC), also known as nanowhiskers, have recently gained much attention due to their biodegradable nature, advantageous chemical and mechanical properties, economic value and renewability thus making them attractive for a wide range of applications. However, before these materials can be considered for potential uses, investigation of their toxicity is prudent. Although CNC exposures are associated with pulmonary inflammation and damage as well as oxidative stress responses and genotoxicity in vivo, studies evaluating cell transformation or tumorigenic potential of CNC's were not previously conducted. In this study, we aimed to assess the neoplastic-like transformation potential of two forms of CNC derived from wood (powder and gel) in human pulmonary epithelial cells (BEAS-2B) in comparison to fibrous tremolite (TF), known to induce lung cancer. Short-term exposure to CNC or TF induced intracellular ROS increase and DNA damage while long-term exposure resulted in neoplastic-like transformation demonstrated by increased cell proliferation, anchorage-independent growth, migration and invasion. The increased proliferative responses were also in-agreement with observed levels of pro-inflammatory cytokines. Based on the hierarchical clustering analysis (HCA) of the inflammatory cytokine responses, CNC powder was segregated from the control and CNC-gel samples. This suggests that CNC may have the ability to influence neoplastic-like transformation events in pulmonary epithelial cells and that such effects are dependent on the type/form of CNC. Further studies focusing on determining and understanding molecular mechanisms underlying potential CNC cell transformation events and their likelihood to induce tumorigenic effects in vivo are highly warranted.

Perceived discrimination and favourable regard toward underweight, normal weight and obese eating disorder sufferers: implications for obesity and eating disorder population health campaigns

Background

Obesity stigma has been shown to increase binge eating, whilst positive regard for eating disorders (EDs) may increase dietary restriction which can also lead to binge eating and weight gain. In the context of increasing prevalence of both obesity and EDs exploring community attitudes towards these illnesses may uncover new variables worthy of consideration in population health campaigns. The aim of the study was to explore community perceived stigma and conversely favourable regard toward eating disorder (ED) sufferers of varying weight status, and understand how the attitudes of obese individuals may differ from those of non-obese individuals. Data for this purpose were derived from interviews with individuals participating in a general population health survey. Vignettes of an underweight female with Anorexia Nervosa (AN), a normal weight male with an atypical eating disorder (NWED) and an obese female with Binge Eating Disorder (BED) were presented to three randomly selected sub-samples of n = 983, 1033 and 1030 respectively. Questions followed that assessed participants’ attitudes towards and beliefs about the person described in the vignette and their eating behaviours.

Results

Sixty-six per cent of participants who responded to the obese BED vignette believed that there would be discrimination against the person described (primarily because of her weight). Corresponding figures were for the AN and NWED vignettes were 48% and 35%, respectively. A positive regard for weight-loss or body-image-enhancing ED behaviours was reported ‘occasionally’ or more often by 8.8% of respondents to the AN vignette and by 27.5% of respondents to the NWED vignette. Positive regard for ED behaviours was significantly more likely in obese participants (AN: 15%; NWED: 43%).

Conclusion

The findings support integrated ED and obesity prevention programs that address weight stigma and the social desirability of ED behaviours in vulnerable individuals.