Proteomics in aging-related research

Ageing in a eusocial insect: molecular and physiological characteristics of life span plasticity in the honey bee

Commonly held views assume that ageing, or senescence, represents an inevitable, passive, and random decline in function that is strongly linked to chronological age. In recent years, genetic intervention of life span regulating pathways, for example, in Drosophila as well as case studies in non-classical animal models, have provided compelling evidence to challenge these views.Rather than comprehensively revisiting studies on the established genetic model systems of ageing, we here focus on an alternative model organism with a wild type (unselected genotype) characterized by a unique diversity in longevity - the honey bee.Honey bee (Apis mellifera) life span varies from a few weeks to more than 2 years. This plasticity is largely controlled by environmental factors. Thereby, although individuals are closely related genetically, distinct life histories can emerge as a function of social environmental change.Another remarkable feature of the honey bee is the occurrence of reverted behavioural ontogeny in the worker (female helper) caste. This behavioural peculiarity is associated with alterations in somatic maintenance functions that are indicative of reverted senescence. Thus, although intraspecific variation in organismal life span is not uncommon, the honey bee holds great promise for gaining insights into regulatory pathways that can shape the time-course of ageing by delaying, halting or even reversing processes of senescence. These aspects provide the setting of our review.We will highlight comparative findings from Drosophila melanogaster and Caenorhabditis elegans in particular, and focus on knowledge spanning from molecular- to behavioural-senescence to elucidate how the honey bee can contribute to novel insights into regulatory mechanisms that underlie plasticity and robustness or irreversibility in ageing.

The salivary glands and saliva of Anopheles gambiae as an essential step in the Plasmodium life cycle: a global proteomic study

Proteins synthesized in the salivary glands of the Anopheles gambiae mosquito are thought to be important in the life cycle of the malaria parasite Plasmodium. To describe A. gambiae salivary gland and saliva contents, we combined several techniques: 1-DE, 2-DE and LC MS/MS. This study has identified five saliva proteins and 122 more proteins from the salivary glands, including the first proteomic description for 89 of these salivary gland proteins. Since the invasion and sporozoite maturation take place during the process of salivary glands ageing, the effect of salivary gland age on salivary component composition was examined. LC MS/MS profiling of young versus old salivary gland proteomes suggests that there is an over-representation of proteins involved in signaling and proteins related to the immune response in the proteins from older mosquitoes. The iTRAQ labeling was used for a comparative proteomic analysis of salivary gland samples from infected or Plasmodium berghei-free mosquitoes. The expression levels of five secreted proteins were altered when the parasite was present. These observations will serve as a basis for future work concerning the possible role of these proteins in the interaction between A. gambiae, Plasmodium and the mammalian host.