Aging and Autophagic Function Influences the Progressive Decline of Adult Drosophila Behaviors

The Influence of Cannabinoids on Drosophila Behaviors, Longevity, and Traumatic Injury Responses of the Adult Nervous System

Introduction: The legalization of cannabis products has increased their usage in the United States. Among the ∼500 active compounds, this is especially true for cannabidiol (CBD)-based products, which are being used to treat a range of ailments. Research is ongoing regarding the safety, therapeutic potential, and molecular mechanism of cannabinoids. Drosophila (fruit flies) are widely used to model a range of factors that impact neural aging, stress responses, and longevity. Materials and Methods: Adult wild-type Drosophila melanogaster cohorts (w1118/+) were treated with different Δ9-tetrahydrocannabinol (THC) and CBD dosages and examined for neural protective properties using established neural aging and trauma models. The therapeutic potential of each compound was assessed using circadian and locomotor behavioral assays and longevity profiles. Changes to NF-κB pathway activation were assessed by measuring expression levels of downstream targets using quantitative real-time polymerase chain reaction analysis of neural cDNAs. Results: Flies exposed to different CBD or THC dosages showed minimal effects to sleep and circadian-based behaviors or the age-dependent decline in locomotion. The 2-week CBD (3 μM) treatment did significantly enhance longevity. Flies exposed to different CBD and THC dosages were also examined under stress conditions, using the Drosophila mild traumatic brain injury (mTBI) model (10×). Pretreatment with either compound did not alter baseline expression of key inflammatory markers (NF-κB targets), but did reduce neural mRNA profiles at a key 4-h time point following mTBI exposure. Locomotor responses were also significantly improved 1 and 2 weeks following mTBI. After mTBI (10×) exposure, the 48-h mortality rate improved for CBD (3 μM)-treated flies, as were global average longevity profiles for other CBD doses tested. While not significant, THC (0.1 μM)-treated flies show a net positive impact on acute mortality and longevity profiles following mTBI (10×) exposure. Conclusions: This study shows that the CBD and THC dosages examined had at most a modest impact on basal neural function, while demonstrating that CBD treatments had significant neural protective properties for flies following exposure to traumatic injury.

Visual feedback neurons fine-tune Drosophila male courtship via GABA-mediated inhibition

Many species of animals use vision to regulate their social behaviors. However, the molecular and circuit mechanisms underlying visually guided social interactions remain largely unknown. Here, we show that the Drosophila ortholog of the human GABAA-receptor-associated protein (GABARAP) is required in a class of visual feedback neurons, lamina tangential (Lat) cells, to fine-tune male courtship. GABARAP is a ubiquitin-like protein that maintains cell-surface levels of GABAA receptors. We demonstrate that knocking down GABARAP or GABAAreceptors in Lat neurons or hyperactivating them induces male courtship toward other males. Inhibiting Lat neurons, on the other hand, delays copulation by impairing the ability of males to follow females. Remarkably, the fly GABARAP protein and its human ortholog share a strong sequence identity, and the fly GABARAP function in Lat neurons can be rescued by its human ortholog. Using in vivo two-photon imaging and optogenetics, we reveal that Lat neurons are functionally connected to neural circuits that mediate visually guided courtship pursuits in males. Our work identifies a novel physiological function for GABARAP in regulating visually guided courtship pursuits in Drosophila males. Reduced GABAA signaling has been linked to social deficits observed in the autism spectrum and bipolar disorders. The functional similarity between the human and the fly GABARAP raises the possibility of a conserved role for this gene in regulating social behaviors across insects and mammals.

Road to sexual maturity: Behavioral event schedule from eclosion to first mating in each sex of Drosophila melanogaster

Animals achieve their first mating through the process of sexual maturation. This study examined the precise and detailed timing of a series of behavioral events, including wing expansion, first feeding, first excretion, and courtship, during sexual maturation from eclosion to first mating in D. melanogaster. We found that the time of first mating is genetically invariant and is not affected by light/dark cycle or food intake after eclosion. We also found sexual dimorphism in locomotor activity after eclosion, with females increasing locomotor activity earlier than males. In addition, we found a time rapidly changing from extremely low to high sexual activity in males post eclosion (named "drastic male courtship arousal" or DMCA). These behavioral traits leading up to the first mating could serve as clear indicators of sexual maturation and establish precisely timed developmental landmarks to explore further the mechanisms underlying the integration of behavioral and physiological sexual maturation.

Restoration of Sleep and Circadian Behavior by Autophagy Modulation in Huntington's Disease

Circadian and sleep defects are well documented in Huntington's disease (HD). Modulation of the autophagy pathway has been shown to mitigate toxic effects of mutant Huntingtin (HTT) protein. However, it is not clear whether autophagy induction can also rescue circadian and sleep defects. Using a genetic approach, we expressed human mutant HTT protein in a subset of Drosophila circadian neurons and sleep center neurons. In this context, we examined the contribution of autophagy in mitigating toxicity caused by mutant HTT protein. We found that targeted overexpression of an autophagy gene, Atg8a in male flies, induces autophagy pathway and partially rescues several HTT-induced behavioral defects, including sleep fragmentation, a key hallmark of many neurodegenerative disorders. Using cellular markers and genetic approaches, we demonstrate that indeed the autophagy pathway is involved in behavioral rescue. Surprisingly, despite behavioral rescue and evidence for the involvement of the autophagy pathway, the large visible aggregates of mutant HTT protein were not eliminated. We show that the rescue in behavior is associated with increased mutant protein aggregation and possibly enhanced output from the targeted neurons, resulting in the strengthening of downstream circuits. Overall, our study suggests that, in the presence of mutant HTT protein, Atg8a induces autophagy and improves the functioning of circadian and sleep circuits.SIGNIFICANCE STATEMENT Defects in sleep and circadian rhythms are well documented in Huntington's disease. Recent literature suggests that circadian and sleep disturbances can exacerbate neurodegenerative phenotypes. Hence, identifying potential modifiers that can improve the functioning of these circuits could greatly improve disease management. We used a genetic approach to enhance cellular proteostasis and found that overexpression of a crucial autophagy gene, Atg8a, induces the autophagy pathway in the Drosophila circadian and sleep neurons and rescues sleep and activity rhythm. We demonstrate that the Atg8a improves synaptic function of these circuits by possibly enhancing the aggregation of the mutant protein in neurons. Further, our results suggest that differences in basal levels of protein homeostatic pathways is a factor that determines selective susceptibility of neurons.

GABA-mediated inhibition in visual feedback neurons fine-tunes Drosophila male courtship

Vision is critical for the regulation of mating behaviors in many species. Here, we discovered that the Drosophila ortholog of human GABA A -receptor-associated protein (GABARAP) is required to fine-tune male courtship by modulating the activity of visual feedback neurons, lamina tangential cells (Lat). GABARAP is a ubiquitin-like protein that regulates cell-surface levels of GABA A receptors. Knocking down GABARAP or GABA A receptors in Lat neurons or hyperactivating them induces male courtship toward other males. Inhibiting Lat neurons, on the other hand, delays copulation by impairing the ability of males to follow females. Remarkably, the human ortholog of Drosophila GABARAP restores function in Lat neurons. Using in vivo two-photon imaging and optogenetics, we show that Lat neurons are functionally connected to neural circuits that mediate visually-guided courtship pursuits in males. Our work reveals a novel physiological role for GABARAP in fine-tuning the activity of a visual circuit that tracks a mating partner during courtship.

Aging: Epigenetic modifications

Aging is one of the most complex and irreversible health conditions characterized by continuous decline in physical/mental activities that eventually poses an increased risk of several diseases and ultimately death. These conditions cannot be ignored by anyone but there are evidences that suggest that exercise, healthy diet and good routines may delay the Aging process significantly. Several studies have demonstrated that Epigenetics plays a key role in Aging and Aging-associated diseases through methylation of DNA, histone modification and non-coding RNA (ncRNA). Comprehension and relevant alterations in these epigenetic modifications can lead to new therapeutic avenues of age-delaying contrivances. These processes affect gene transcription, DNA replication and DNA repair, comprehending epigenetics as a key factor in understanding Aging and developing new avenues for delaying Aging, clinical advancements in ameliorating aging-related diseases and rejuvenating health. In the present article, we have described and advocated the epigenetic role in Aging and associated diseases.

Electronic recording of lifetime locomotory activity patterns of adult medflies

Age-specific and diurnal patterns of locomotory activity, can be considered as biomarkers of aging in model organisms and vary across the lifetime of individuals. Τhe Mediterranean fruit fly (medfly), Ceratitis capitata, is a commonly used model-species in studies regarding demography and aging. In the present study, we introduce a modification of the automated locomotory activity electronic device LAM25system (Locomotory Activity Monitor)-Trikinetics, commonly used in short time studies, to record the daily locomotory activity patterns of adult medflies throughout the life. Additionally, fecundity rates and survival of adult medflies were recorded. Male and female medflies were kept in the system tubes and had access to an agar-based gel diet, which provided water and nutrients. The locomotory activity was recorded at every minute by three monitors in the electronic device. The locomotory activity of females was higher than that of males across the different ages. For both sexes locomotory rates were high during the first 20 days of the adult life and decreased in older ages. The activity of males was high in the morning and late afternoon hours, while that of females was constantly high throughout the photophase. Negligible locomotory activity was recorded for both sexes during the nighttime. Males outlived females. Fecundity of females was higher in younger ages. Our results support the adoption of LAM25system in studies addressing aging of insects using medfly as a model organism.

Dietary restriction ameliorates TBI-induced phenotypes in Drosophila melanogaster

Traumatic brain injury (TBI) affects millions annually and is associated with long-term health decline. TBI also shares molecular and cellular hallmarks with neurodegenerative diseases (NDs), typically increasing in prevalence with age, and is a major risk factor for developing neurodegeneration later in life. While our understanding of genes and pathways that underlie neurotoxicity in specific NDs has advanced, we still lack a complete understanding of early molecular and physiological changes that drive neurodegeneration, particularly as an individual ages following a TBI. Recently Drosophila has been introduced as a model organism for studying closed-head TBI. In this paper, we deliver a TBI to flies early in adult life, and then measure molecular and physiological phenotypes at short-, mid-, and long-term timepoints following the injury. We aim to identify the timing of changes that contribute to neurodegeneration. Here we confirm prior work demonstrating a TBI-induced decline in lifespan, and present evidence of a progressive decline in locomotor function, robust acute and modest chronic neuroinflammation, and a late-onset increase in protein aggregation. We also present evidence of metabolic dysfunction, in the form of starvation sensitivity and decreased lipids, that persists beyond the immediate injury response, but does not differ long-term. An intervention of dietary restriction (DR) partially ameliorates some TBI-induced phenotypes, including lifespan and locomotor function, though it does not alter the pattern of starvation sensitivity of injured flies. In the future, molecular pathways identified as altered following TBI—particularly in the short-, or mid-term—could present potential therapeutic targets.

Treatment with Bacterial Biologics Promotes Healthy Aging and Traumatic Brain Injury Responses in Adult Drosophila, Modeling the Gut-Brain Axis and Inflammation Responses

Drosophila are widely used to study neural development, immunity, and inflammatory pathways and processes associated with the gut-brain axis. Here, we examine the response of adult Drosophila given an inactive bacteriologic (IAB; proprietary lysate preparation of Lactobacillus bulgaricus, ReseT®) and a probiotic (Lactobacillus rhamnosus, LGG). In vitro, the IAB activates a subset of conserved Toll-like receptor (TLR) and nucleotide-binding, oligomerization domain-containing protein (NOD) receptors in human cells, and oral administration slowed the age-related decline of adult Drosophila locomotor behaviors. On average, IAB-treated flies lived significantly longer (+23%) and had lower neural aggregate profiles. Different IAB dosages also improved locomotor function and longevity profiles after traumatic brain injury (TBI) exposure. Mechanistically, short-term IAB and LGG treatment altered baseline nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κβ) signaling profiles in neural and abdominal tissues. Overall, at select dosages, IAB and LGG exposure has a positive impact on Drosophila longevity, neural aging, and mild traumatic brain injury (TBI)-related responses, with IAB showing greater benefit. This includes severe TBI (sTBI) responses, where IAB treatment was protective and LGG increased acute mortality profiles. This work shows that Drosophila are an effective model for testing bacterial-based biologics, that IAB and probiotic treatments promote neuronal health and influence inflammatory pathways in neural and immune tissues. Therefore, targeted IAB treatments are a novel strategy to promote the appropriate function of the gut-brain axis.

epg5 knockout leads to the impairment of reproductive success and courtship behaviour in a zebrafish model of autophagy-related diseases

Background

Dysregulation of the autophagic flux is linked to a wide array of human diseases, and recent findings highlighted the central role of autophagy in reproduction, as well as an association between impairment of autophagy and behavioural disorders. Here we deepened on the possible multilevel link between impairment of the autophagic processes and reproduction at both the physiological and the behavioural level in a zebrafish mutant model.

Methods

Using a KO epg5 zebrafish line we analysed male breeding success, fertility rate, offspring survival, ejaculate quality, sperm and testes morphology, and courtship behaviour. To this aim physiological, histological, ultrastructural and behavioural analyses on epg5^+/+ and mutant epg5^−/− males coupled to WT females were applied.

Results

We observed an impairment of male reproductive performance in mutant epg5^−/− males that showed a lower breeding success with a reduced mean number of eggs spawned by their WT female partners. The spermatogenesis and the ability to produce fertilising ejaculates were not drastically impaired in our mutant males, whereas we observed a reduction of their courtship behaviour that might contribute to explain their lower overall reproductive success.

Conclusion

Collectively our findings corroborate the hypothesis of a multilevel link between the autophagic process and reproduction. Moreover, by giving a first glimpse on behavioural disorders associated to epg5 KO in model zebrafish, our results open the way to more extensive behavioural analyses, also beyond the reproductive events, that might serve as new tools for the molecular screening of autophagy-related multisystemic and neurodegenerative diseases.

Targeting the core of neurodegeneration: FoxO, mTOR, and SIRT1

The global increase in lifespan noted not only in developed nations, but also in large developing countries parallels an observed increase in a significant number of non-communicable diseases, most notable neurodegenerative disorders. Neurodegenerative disorders present a number of challenges for treatment options that do not resolve disease progression. Furthermore, it is believed by the year 2030, the services required to treat cognitive disorders in the United States alone will exceed $2 trillion annually. Mammalian forkhead transcription factors, silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae), the mechanistic target of rapamycin, and the pathways of autophagy and apoptosis offer exciting avenues to address these challenges by focusing upon core cellular mechanisms that may significantly impact nervous system disease. These pathways are intimately linked such as through cell signaling pathways involving protein kinase B and can foster, sometimes in conjunction with trophic factors, enhanced neuronal survival, reduction in toxic intracellular accumulations, and mitochondrial stability. Feedback mechanisms among these pathways also exist that can oversee reparative processes in the nervous system. However, mammalian forkhead transcription factors, silent mating type information regulation 2 homolog 1, mechanistic target of rapamycin, and autophagy can lead to cellular demise under some scenarios that may be dependent upon the precise cellular environment, warranting future studies to effectively translate these core pathways into successful clinical treatment strategies for neurodegenerative disorders.

Synergistic action of propolis with levodopa in the management of Parkinsonism in Drosophila melanogaster

Background The Phosphatase and tensin-induced putative kinase 1 (PINK1B9) mutant for Drosophila melanogaster is a key tool that has been used in assessing the pathology of Parkinsonism and its possible remedy. This research was targeted toward determining the effects of ethanolic extract of propolis, with levodopa therapy in the management of Parkinsonism. Method The PINK1B9 flies were divided into groups and fed with the different treatment doses of ethanoic extract of propolis. The treatment groups were subjected to 21 days of administration of propolis and the levodopa at different doses after which percentage climbing index, antioxidant activity and lifespan studies were done. Results Propolis alone improved motor activity, antioxidant and lifespan in Drosophila melanogaster than in PINK1 flies. Propolis in combination with levodopa significantly (P<0.05) improved physiological parameters at higher than lower concentrations in Parkinsonism Drosophila melanogaster demonstrating its importance in managing side effects associated with levodopa. Conclusion Propolis is a novel candidate as an alternative and integrative medicinal option to use in the management of Parkinsonism in both animals and humans at higher concentrations.

Dysregulation of metabolic flexibility: The impact of mTOR on autophagy in neurodegenerative disease

Non-communicable diseases (NCDs) that involve neurodegenerative disorders and metabolic disease impact over 400 million individuals globally. Interestingly, metabolic disorders, such as diabetes mellitus, are significant risk factors for the development of neurodegenerative diseases. Given that current therapies for these NCDs address symptomatic care, new avenues of discovery are required to offer treatments that affect disease progression. Innovative strategies that fill this void involve the mechanistic target of rapamycin (mTOR) and its associated pathways of mTOR complex 1 (mTORC1), mTOR complex 2 (mTORC2), AMP activated protein kinase (AMPK), trophic factors that include erythropoietin (EPO), and the programmed cell death pathways of autophagy and apoptosis. These pathways are intriguing in their potential to provide effective care for metabolic and neurodegenerative disorders. Yet, future work is necessary to fully comprehend the entire breadth of the mTOR pathways that can effectively and safely translate treatments to clinical medicine without the development of unexpected clinical disabilities.

New Insights for nicotinamide: Metabolic disease, autophagy, and mTOR

Metabolic disorders, such as diabetes mellitus (DM), are increasingly becoming significant risk factors for the health of the global population and consume substantial portions of the gross domestic product of all nations. Although conventional therapies that include early diagnosis, nutritional modification of diet, and pharmacological treatments may limit disease progression, tight serum glucose control cannot prevent the onset of future disease complications. With these concerns, novel strategies for the treatment of metabolic disorders that involve the vitamin nicotinamide, the mechanistic target of rapamycin (mTOR), mTOR Complex 1 (mTORC1), mTOR Complex 2 (mTORC2), AMP activated protein kinase (AMPK), and the cellular pathways of autophagy and apoptosis offer exceptional promise to provide new avenues of treatment. Oversight of these pathways can promote cellular energy homeostasis, maintain mitochondrial function, improve glucose utilization, and preserve pancreatic beta-cell function. Yet, the interplay among mTOR, AMPK, and autophagy pathways can be complex and affect desired clinical outcomes, necessitating further investigations to provide efficacious treatment strategies for metabolic dysfunction and DM.

Investigating Alcohol Behavior and Physiology Using Drosophila melanogaster

Drosophila melanogaster, the fruit fly, is one of the most versatile models for biomedical studies due to the economical husbandry, rapid generation time, and the array of tools for spatial and temporal gene manipulation. The relatively short lifespan of Drosophila (60-80 days) and the high degree of molecular conservation across species make Drosophila ideal to study the complexities of aging. Alcohol is the most abused drug worldwide and alcohol use disorders represent a significant public health problem and economic burden to individuals and society. Stereotypical alcohol-induced behaviors and the underlying molecular mechanisms are conserved from flies to humans making Drosophila a practical model for investigating the development of alcohol-induced behaviors and alcohol pathologies. Here, we outline how to assemble an efficient and controlled alcohol vapor delivery system, the FlyBar, and review paradigms and protocols for the assessment of alcohol-induced behaviors and physiology in Drosophila including the loss-of-righting reflex, sedation, tolerance, alcohol metabolism, and gut permeability.

Aging and the clock: Perspective from flies to humans

Endogenous circadian oscillators regulate molecular, cellular and physiological rhythms, synchronizing tissues and organ function to coordinate activity and metabolism with environmental cycles. The technological nature of modern society with round-the-clock work schedules and heavy reliance on personal electronics has precipitated a striking increase in the incidence of circadian and sleep disorders. Circadian dysfunction contributes to an increased risk for many diseases and appears to have adverse effects on aging and longevity in animal models. From invertebrate organisms to humans, the function and synchronization of the circadian system weakens with age aggravating the age-related disorders and pathologies. In this review, we highlight the impacts of circadian dysfunction on aging and longevity and the reciprocal effects of aging on circadian function with examples from Drosophila to humans underscoring the highly conserved nature of these interactions. Additionally, we review the potential for using reinforcement of the circadian system to promote healthy aging and mitigate age-related pathologies. Advancements in medicine and public health have significantly increased human life span in the past century. With the demographics of countries worldwide shifting to an older population, there is a critical need to understand the factors that shape healthy aging. Drosophila melanogaster, as a model for aging and circadian interactions, has the capacity to facilitate the rapid advancement of research in this area and provide mechanistic insights for targeted investigations in mammals.

Social behavior and aging: A fly model

The field of behavioral genetics has recently begun to explore the effect of age on social behaviors. Such studies are particularly important, as certain neuropsychiatric disorders with abnormal social interactions, like autism and schizophrenia, have been linked to older parents. Appropriate social interaction can also have a positive impact on longevity, and is associated with successful aging in humans. Currently, there are few genetic models for understanding the effect of aging on social behavior and its potential transgenerational inheritance. The fly is emerging as a powerful model for identifying the basic molecular mechanisms underlying neurological and neuropsychiatric disorders. In this review, we discuss these recent advancements, with a focus on how studies in Drosophila melanogaster have provided insight into the effect of aging on aspects of social behavior, including across generations.

Moving to the Rhythm with Clock (Circadian) Genes, Autophagy, mTOR, and SIRT1 in Degenerative Disease and Cancer

BACKGROUND

The mammalian circadian clock and its associated clock genes are increasingly been recognized as critical components for a number of physiological and disease processes that extend beyond hormone release, thermal regulation, and sleep-wake cycles. New evidence suggests that clinical behavior disruptions that involve prolonged shift work and even space travel may negatively impact circadian rhythm and lead to multi-system disease.

METHODS

In light of the significant role circadian rhythm can hold over the body's normal physiology as well as disease processes, we examined and discussed the impact circadian rhythm and clock genes hold over lifespan, neurodegenerative disorders, and tumorigenesis.

RESULTS

In experimental models, lifespan is significantly reduced with the introduction of arrhythmic mutants and leads to an increase in oxidative stress exposure. Interestingly, patients with Alzheimer's disease and Parkinson's disease may suffer disease onset or progression as a result of alterations in the DNA methylation of clock genes as well as prolonged pharmacological treatment for these disorders that may lead to impairment of circadian rhythm function. Tumorigenesis also can occur with the loss of a maintained circadian rhythm and lead to an increased risk for nasopharyngeal carcinoma, breast cancer, and metastatic colorectal cancer. Interestingly, the circadian clock system relies upon the regulation of the critical pathways of autophagy, the mechanistic target of rapamycin (mTOR), AMP activated protein kinase (AMPK), and silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1) as well as proliferative mechanisms that involve the wingless pathway of Wnt/β-catenin pathway to foster cell survival during injury and block tumor cell growth.

CONCLUSION

Future targeting of the pathways of autophagy, mTOR, SIRT1, and Wnt that control mammalian circadian rhythm may hold the key for the development of novel and effective therapies against aging- related disorders, neurodegenerative disease, and tumorigenesis.

Aging and Intermittent Fasting Impact on Transcriptional Regulation and Physiological Responses of Adult Drosophila Neuronal and Muscle Tissues

The progressive decline of the nervous system, including protein aggregate formation, reflects the subtle dysregulation of multiple functional pathways. Our previous work has shown intermittent fasting (IF) enhances longevity, maintains adult behaviors and reduces aggregates, in part, by promoting autophagic function in the aging Drosophila brain. To clarify the impact that IF-treatment has upon aging, we used high throughput RNA-sequencing technology to examine the changing transcriptome in adult Drosophila tissues. Principle component analysis (PCA) and other analyses showed ~1200 age-related transcriptional differences in head and muscle tissues, with few genes having matching expression patterns. Pathway components showing age-dependent expression differences were involved with stress response, metabolic, neural and chromatin remodeling functions. Middle-aged tissues also showed a significant increase in transcriptional drift-variance (TD), which in the CNS included multiple proteolytic pathway components. Overall, IF-treatment had a demonstrably positive impact on aged transcriptomes, partly ameliorating both fold and variance changes. Consistent with these findings, aged IF-treated flies displayed more youthful metabolic, behavioral and basal proteolytic profiles that closely correlated with transcriptional alterations to key components. These results indicate that even modest dietary changes can have therapeutic consequences, slowing the progressive decline of multiple cellular systems, including proteostasis in the aging nervous system.

The mitochondrial ATP synthase is a shared drug target for aging and dementia

Aging is a major driving force underlying dementia, such as that caused by Alzheimer's disease (AD). While the idea of targeting aging as a therapeutic strategy is not new, it remains unclear how closely aging and age-associated diseases are coupled at the molecular level. Here, we discover a novel molecular link between aging and dementia through the identification of the molecular target for the AD drug candidate J147. J147 was developed using a series of phenotypic screening assays mimicking disease toxicities associated with the aging brain. We have previously demonstrated the therapeutic efficacy of J147 in several mouse models of AD. Here, we identify the mitochondrial α-F1 -ATP synthase (ATP5A) as a target for J147. By targeting ATP synthase, J147 causes an increase in intracellular calcium leading to sustained calcium/calmodulin-dependent protein kinase kinase β (CAMKK2)-dependent activation of the AMPK/mTOR pathway, a canonical longevity mechanism. Accordingly, modulation of mitochondrial processes by J147 prevents age-associated drift of the hippocampal transcriptome and plasma metabolome in mice and extends lifespan in drosophila. Our results link aging and age-associated dementia through ATP synthase, a molecular drug target that can potentially be exploited for the suppression of both. These findings demonstrate that novel screens for new AD drug candidates identify compounds that act on established aging pathways, suggesting an unexpectedly close molecular relationship between the two.

The mechanistic target of rapamycin (mTOR) and the silent mating-type information regulation 2 homolog 1 (SIRT1): oversight for neurodegenerative disorders

As a result of the advancing age of the global population and the progressive increase in lifespan, neurodegenerative disorders continue to increase in incidence throughout the world. New strategies for neurodegenerative disorders involve the novel pathways of the mechanistic target of rapamycin (mTOR) and the silent mating-type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1) that can modulate pathways of apoptosis and autophagy. The pathways of mTOR and SIRT1 are closely integrated. mTOR forms the complexes mTOR Complex 1 and mTOR Complex 2 and can impact multiple neurodegenerative disorders that include Alzheimer's disease, Huntington's disease, and Parkinson's disease. SIRT1 can control stem cell proliferation, block neuronal injury through limiting programmed cell death, drive vascular cell survival, and control clinical disorders that include dementia and retinopathy. It is important to recognize that oversight of programmed cell death by mTOR and SIRT1 requires a fine degree of precision to prevent the progression of neurodegenerative disorders. Additional investigations and insights into these pathways should offer effective and safe treatments for neurodegenerative disorders.

Progeny of old parents have increased social space in Drosophila melanogaster

We report the effects of aging and parental age in Drosophila melanogaster on two types of responses to social cues: the choice of preferred social spacing in an undisturbed group and the response to the Drosophila stress odorant (dSO) emitted by stressed flies. The patterns of changes during aging were notably different for these two social responses. Flies were initially closer in space and then became further apart. However, the pattern of change in response to dSO followed a more typical decline in performance, similarly to changes in locomotion. Interestingly, the increased social space of old parents, as well as their reduced performance in avoiding dSO, was passed on to their progeny, such that young adults adopted the behavioural characteristic of their old parents. While the response to social cues was inherited, the changes in locomotion were not. We were able to scale the changes in the social space of parents and their progeny by accelerating or decelerating the physiological process of aging by increasing temperatures and exposure to oxidative stress, or via caloric restriction, respectively. Finally, when we aged only one parent, only the male progeny of old fathers and the progeny of very old mothers were more distant.

Novel Treatment Strategies for the Nervous System: Circadian Clock Genes, Non-coding RNAs, and Forkhead Transcription Factors

BACKGROUND

With the global increase in lifespan expectancy, neurodegenerative disorders continue to affect an ever-increasing number of individuals throughout the world. New treatment strategies for neurodegenerative diseases are desperately required given the lack of current treatment modalities.

METHODS

Here, we examine novel strategies for neurodegenerative disorders that include circadian clock genes, non-coding Ribonucleic Acids (RNAs), and the mammalian forkhead transcription factors of the O class (FoxOs).

RESULTS

Circadian clock genes, non-coding RNAs, and FoxOs offer exciting prospects to potentially limit or remove the significant disability and death associated with neurodegenerative disorders. Each of these pathways has an intimate relationship with the programmed death pathways of autophagy and apoptosis and share a common link to the silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1) and the mechanistic target of rapamycin (mTOR). Circadian clock genes are necessary to modulate autophagy, limit cognitive loss, and prevent neuronal injury. Non-coding RNAs can control neuronal stem cell development and neuronal differentiation and offer protection against vascular disease such as atherosclerosis. FoxOs provide exciting prospects to block neuronal apoptotic death and to activate pathways of autophagy to remove toxic accumulations in neurons that can lead to neurodegenerative disorders.

CONCLUSION

Continued work with circadian clock genes, non-coding RNAs, and FoxOs can offer new prospects and hope for the development of vital strategies for the treatment of neurodegenerative diseases. These innovative investigative avenues have the potential to significantly limit disability and death from these devastating disorders.

Drosophila: An Emergent Model for Delineating Interactions between the Circadian Clock and Drugs of Abuse

Endogenous circadian oscillators orchestrate rhythms at the cellular, physiological, and behavioral levels across species to coordinate activity, for example, sleep/wake cycles, metabolism, and learning and memory, with predictable environmental cycles. The 21st century has seen a dramatic rise in the incidence of circadian and sleep disorders with globalization, technological advances, and the use of personal electronics. The circadian clock modulates alcohol- and drug-induced behaviors with circadian misalignment contributing to increased substance use and abuse. Invertebrate models, such as Drosophila melanogaster, have proven invaluable for the identification of genetic and molecular mechanisms underlying highly conserved processes including the circadian clock, drug tolerance, and reward systems. In this review, we highlight the contributions of Drosophila as a model system for understanding the bidirectional interactions between the circadian system and the drugs of abuse, alcohol and cocaine, and illustrate the highly conserved nature of these interactions between Drosophila and mammalian systems. Research in Drosophila provides mechanistic insights into the corresponding behaviors in higher organisms and can be used as a guide for targeted inquiries in mammals.

Autophagy and Human Neurodegenerative Diseases-A Fly's Perspective

Neurodegenerative diseases in humans are frequently associated with prominent accumulation of toxic protein inclusions and defective organelles. Autophagy is a process of bulk lysosomal degradation that eliminates these harmful substances and maintains the subcellular environmental quality. In support of autophagy's importance in neuronal homeostasis, several genetic mutations that interfere with autophagic processes were found to be associated with familial neurodegenerative disorders. In addition, genetic mutations in autophagy-regulating genes provoked neurodegenerative phenotypes in animal models. The Drosophila model significantly contributed to these recent developments, which led to the theory that autophagy dysregulation is one of the major underlying causes of human neurodegenerative disorders. In the current review, we discuss how studies using Drosophila enhanced our understanding of the relationship between autophagy and neurodegenerative processes.

Assessing Basal and Acute Autophagic Responses in the Adult Drosophila Nervous System: The Impact of Gender, Genetics and Diet on Endogenous Pathway Profiles

The autophagy pathway is critical for the long-term homeostasis of cells and adult organisms and is often activated during periods of stress. Reduced pathway efficacy plays a central role in several progressive neurological disorders that are associated with the accumulation of cytotoxic peptides and protein aggregates. Previous studies have shown that genetic and transgenic alterations to the autophagy pathway impacts longevity and neural aggregate profiles of adult Drosophila. In this study, we have identified methods to measure the acute in vivo induction of the autophagy pathway in the adult fly CNS. Our findings indicate that the genotype, age, and gender of adult flies can influence pathway responses. Further, we demonstrate that middle-aged male flies exposed to intermittent fasting (IF) had improved neuronal autophagic profiles. IF-treated flies also had lower neural aggregate profiles, maintained more youthful behaviors and longer lifespans, when compared to ad libitum controls. In summary, we present methodology to detect dynamic in vivo changes that occur to the autophagic profiles in the adult Drosophila CNS and that a novel IF-treatment protocol improves pathway response in the aging nervous system.

Conserved regulators of cognitive aging: From worms to humans

Cognitive decline is a major deficit that arises with age in humans. While some research on the underlying causes of these problems can be done in humans, harnessing the strengths of small model systems, particularly those with well-studied longevity mutants, such as the nematode C. elegans, will accelerate progress. Here we review the approaches being used to study cognitive decline in model organisms and show how simple model systems allow the rapid discovery of conserved molecular mechanisms, which will eventually enable the development of therapeutics to slow cognitive aging.

Using Drosophila as an integrated model to study mild repetitive traumatic brain injury

Traumatic brain injury (TBI) is a major cause of morbidity and mortality worldwide. In addition, there has been a growing appreciation that even repetitive, milder forms of TBI (mTBI) can have long-term deleterious consequences to neural tissues. Hampering our understanding of genetic and environmental factors that influence the cellular and molecular responses to injury has been the limited availability of effective genetic model systems that could be used to identify the key genes and pathways that modulate both the acute and long-term responses to TBI. Here we report the development of a severe and mild-repetitive TBI model using Drosophila. Using this system, key features that are typically found in mammalian TBI models were also identified in flies, including the activation of inflammatory and autophagy responses, increased Tau phosphorylation and neuronal defects that impair sleep-related behaviors. This novel injury paradigm demonstrates the utility of Drosophila as an effective tool to validate genetic and environmental factors that influence the whole animal response to trauma and to identify prospective therapies needed for the treatment of TBI.