Defensive Behavior against Noxious Heat Stimuli Is Declined with Aging Due to Decreased Pain-Associated Gene Expression in Drosophila

Behavioral changes in senescent giant Pacific octopus (Enteroctopus dofleini) are associated with peripheral neural degeneration and loss of epithelial tissue

Most species of octopus experience extreme physical decline after a single reproductive bout which extends over a period of days, weeks, or months before eventual death. Although outward indicators of senescence are widely recognized, comparatively little is known about physiological and neural changes accompanying terminal decline in octopuses. Here, we measured changes in behavioral response to nociceptive stimuli across the lifespan in giant Pacific octopus (GPO), Enteroctopus dofleini, held in public aquariums in the USA. Post-euthanasia, tissue was collected from arm tips, and neural and epithelial cell degeneration was quantified and compared with biopsies of arm tips from healthy, pre-reproductive GPOs. Behavioral assays showed significant changes both in low threshold mechanosensory responses and nociceptive behavioral responses beginning early in senescence and extending until euthanasia. Histology data showed that while the ratio of apoptotic cells to total cell number stayed constant between healthy and senescent GPOs, overall neural and epithelial cell density was significantly lower in terminally senescent octopuses compared with healthy controls. Our data provide new insight into the time-course and causes of sensory dysfunction in senescent cephalopods and suggest proactive welfare management should begin early in the senescence phase, well before animals enter terminal decline.

Fan-Shaped Body Neurons in the Drosophila Brain Regulate Both Innate and Conditioned Nociceptive Avoidance

Multiple brain regions respond to harmful nociceptive stimuli. However, it remains unclear as to whether behavioral avoidance of such stimuli can be modulated within the same or distinct brain networks. Here, we found subgroups of neurons localized within a well-defined brain region capable of mediating both innate and conditioned nociceptive avoidance in Drosophila. Neurons in the ventral, but not the dorsal, of the multiple-layer organized fan-shaped body (FB) are responsive to electric shock (ES). Silencing ES-responsive neurons, but not non-responsive neurons, leads to reduced avoidance of harmful stimuli, including ES and heat shock. Activating these neurons consistently triggers avoidance and can serve as an unconditional stimulus in an aversive classical conditioning task. Among the three groups of responsive neurons identified, two also have reduced activity in ES-conditioned odor avoidance. These results demonstrate that both innate and conditioned nociceptive avoidance might be represented within neurons confined to a single brain region.

A proteomic approach reveals the differential protein expression in Drosophila melanogaster treated with red ginseng extract (Panax ginseng)

Background

Red ginseng is a popularly used traditional medicine with antiaging effects in Asian countries. The present study aimed to explore the changes in protein expression underlying the mechanisms of life span extension and antiaging caused by red ginseng extract (RGE) in Drosophila melanogaster.

Methods

A proteomic approach of two-dimensional polyacrylamide gel electrophoresis (2-DE) was used to identify the differential abundance of possible target proteins of RGE in D. melanogaster. The reliability of the 2-DE results was confirmed via Western blotting to measure the expression levels of selected proteins. Proteins altered at the expression level after RGE treatment (1 mg/mL) were identified by matrix-assisted laser desorption/ionization-time of flight tandem mass spectrometry and by searching against the National Center for Biotechnology nonredundant and Uniprot protein databases. The differentially expressed proteins were analyzed using bioinformatics methods.

Results

The average survival life span of D. melanogaster was significantly extended by 12.60% with RGE treatment (1 mg/mL) compared to untreated flies. This followed increased superoxide dismutase level and decreased methane dicarboxylic aldehyde content. Based on the searching strategy, 23 differentially expressed proteins were identified (16 up-regulated and 7 down-regulated) in the RGE-treated D. melanogaster. Transduction pathways were identified using the Kyoto Encyclopedia of Genes and Genomes database, and included the hippo and oxidative phosphorylation pathways that play important roles in life span extension and antiaging process of D. melanogaster.

Conclusion

Treatment with RGE in D. melanogaster demonstrated that mechanisms of life span extension and antiaging are regulated by multiple factors and complicated signal pathways.

Jujube (Ziziphus Jujuba Mill.) fruit feeding extends lifespan and increases tolerance to environmental stresses by regulating aging-associated gene expression in Drosophila

Jujube (Ziziphus Jujuba Mill.) fruit has been utilized as an adjunct to alleviate medical symptoms including, but not limited to, anorexia, fatigue, anxiety and mild diarrhea for centuries. Despite a growing body of literature revealing jujube fruit's health promoting properties such as anti-cancer, anti-inflammation and anti-oxidant effects (shown with cell-based in vitro platforms), there is a paucity of studies systemically examining its impact on whole organisms or throughout the entire course of life utilizing in vivo model systems. Thus, here in this study, we conducted a series of experiments to investigate if jujube fruit can modify an organism's longevity using a live Drosophila model. We found that jujube fruit feeding extended not only lifespan but also healthspan examined by stress assays such as starvation and paraquat treatment. In an effort to shed light on the mechanisms of these jujube-related benefits at the molecular level, we report that messenger RNA (mRNA) levels of 14-3-3ε, a negative FoxO (Forkhead box O transcription factor) regulator, was dramatically diminished while the abundance of d4E-BP mRNA transcript (drosophila eukaryotic translation initiation factor 4E binding protein), a FoxO target gene, was increased, suggesting enhanced FoxO activity with jujube fruit feeding. In conclusion, we hope our results will lead to multidisciplinary research to investigate the potential benefit of jujube fruit as a novel anti-aging agent.