Hyperoxia-induced neurodegeneration as a tool to identify neuroprotective genes in Drosophila melanogaster

Knocking down expression of Hsp22 and Hsp23 by RNA interference affects recovery from chill coma in Drosophila melanogaster

“…Both Hsp22 and Hsp23 are involved in protection from the disturbance of normal redox state in D. melanogaster. Indeed, Hsp23 plays important role in hypoxia tolerance (Azad et al, 2009), whereas Hsp22 has a protective role in hyperoxia (Gruenewald et al, 2009). Maintenance of the oxidant equilibrium might be important during recovery, especially because perturbation of the antioxidant system is known to be related to chilling injury in insects (Rojas and Leopold, 1996;Grubor-Lajsic et al, 1997;Jing et al, 2005).…”

Do the Genes of the Innate Immune Response Contribute to Neuroprotection in Drosophila?

“…We were intrigued about whether immune response genes are also overrepresented in responses to adverse conditions other than neurodegeneration. Our review of published results led us to conclude that they are indeed overrepresented among the genes responding to oxidative stress [30,31], mechanical stress [32], endoplasmic reticulum (ER) stress [33,34], starvation [35,36,37], hypoxia [38], osmotic stress [39], wing disk regeneration [40], ionizing irradiation [41] or UV irradiation-mediated DNA damage [42] (table 2). …”

“…For example, the humoral factor Turandot, TotA , is induced by exposure to bacteria, heat stress, oxidative stress, mechanical stress, UV radiation and dehydration [43]. Among 449 genes with abnormally high transcripts in the head of flies exposed to hyperoxia, 68 are also upregulated in flies challenged by dietary administration of hydrogen peroxide or other protocols that cause oxidative stress [31]. Tens of genes are regulated by oxidative stress (regardless of whether this condition is caused by hyperoxia or hydrogen peroxide) and also by heat stress or ionizing radiation [44].…”

“…Some genes are regulated both by tunicamycin (which induces a form of ER stress) and by oxidative stress caused either by hydrogen peroxide or paraquat [33]. At least for some of the genes regulated upon a variety of challenges it is reasonably well established that their regulation confers tolerance or protection against the experimental challenge [31,33,43,44]. …”

“…For example, genes responding to heat shock ( Hsp70Bc and other Hsp genes) [31,55,56] or oxidative challenge ( Sod ) [31,57,58] have neuroprotective function. Among 126 genes for which RNA interference either suppresses or enhances the neurodegenerative phenotype associated with Huntingtin aggregates, 8 genes (6.3%) belong to the immune response group [59].…”