A FAT-PROMOTING BOTANICAL EXTRACT ARTEMISIA SCOPARIA EXERTS GEROPROTECTION IN C. ELEGANS

Abstract Like other biological processes, aging is not random but subject to molecular control. Natural products that modify core metabolic parameters, including fat content, may provide entry points to extend animal lifespan and promote healthy aging. Here, we show that a botanical extract from Artemisia scoparia (SCO), which promotes fat storage and metabolic resiliency in mice, extends the lifespan of the nematode Caenorhabditis elegans by up to 40%. Notably, this lifespan extension depends significantly on SCO’s effects on fat; SCO-treated worms exhibit heightened levels of unsaturated fat, and inhibiting Δ9 desaturases, which oversee biosynthesis of monounsaturated fatty acids, prevents SCO-dependent fat accumulation and lifespan extension. At an upstream signaling level, SCO prompts changes to C. elegans fat regulation by stimulating nuclear translocation of transcription factor DAF-16/FOXO, an event that requires AMP-activated protein kinase under this condition. Importantly, animals treated with SCO are not only long lived but also show improved stress resistance in late adulthood, suggesting that this fat-promoting intervention may enhance some aspects of physiological health in older age. These findings identify SCO as a natural product that can modify fat regulation for longevity benefit and add to growing evidence indicating that elevated fat can be pro-longevity in some circumstances.

and metabolites influence a range of molecular processes critical to healthy aging, including regulation of inflammatory and immune responses, cellular redox homeostasis, and energy production.Aberrant kynurenine metabolism occurs during normal aging and is implicated in many age-associated pathologies including chronic inflammation, atherosclerosis, neurodegeneration, and cancer.We and others previously identified three kynurenine pathway genes-kynu-1, tdo-2, and acsd-1-for which decreasing expression extends lifespan in invertebrates.More recently we discovered that knockdown of haao-1, a fourth kynurenine pathway gene encoding the enzyme 3-hydroxyanthranilic acid dioxygenase (HAAO), extends lifespan by ~30% and delays age-associated health decline in Caenorhabditis elegans.Lifespan extension is mediated by increased physiological levels of the HAAO substrate 3-hydroxyanthranilic acid (3HAA).Aging mice fed a diet supplemented with 3HAA are similarly long-lived.The mechanism of action liking 3HAA to aging is complex and partially overlaps with multiple pathways previously implicated in aging.We recently identified activation of the Nrf2/SKN-1 oxidative stress response and alterations to iron homeostasis as key players in the benefits 3HAA.Ongoing work explores the relationship between 3HAA, Nrf2/SKN-1, and iron in C. elegans and mammalian aging, age-associated immune decline, and cancer.This works provides a foundation for detailed examination of the molecular mechanisms underlying the benefits of 3HAA, and how these mechanisms interact with other antiaging interventions.We anticipate that these findings will bolster growing interest in developing pharmacological strategies to target tryptophan metabolism to improve health aging.

LEVERAGING THE NDUFS4-/-MOUSE AS A PLATFORM FOR TESTING LONGEVITY INTERVENTIONS
Alessandro Bitto, Cara Tobey, Ayush Sharma, Anthony Grillo, and Matt Kaeberlein, University of Washington, Seattle, Washington, United States Mitochondrial dysfunction is one of the hallmarks of biological aging, as well as the driving factor for mitochondrial diseases.Up to 30% of mitochondrial disorders are due to mutations affecting the activity of Complex I in the electron transport chain.Loss of the Complex I subunit Ndufs4 recapitulates symptoms of Leigh Syndrome, a pediatric mitochondrial disease, in mouse.Ndufs4-/-mice suffer developmental delays, early onset of neurological symptoms and extremely reduced lifespan.Several studies have now shown that Ndufs4-/-mice are exquisitely responsive to treatments and interventions of interest in the biology of aging, such as rapamycin, NAD+ precursors, reduced oxygen tension, alphaketo-glutarate precursors, and the antidiabetic drug acarbose.These results point to common mechanisms underlying both aging and mitochondrial disorders.To put this hypothesis to the test, we show that Ndufs4-/-mice are responsive to a wide range of longevity interventions previously tested in worms, mice, and by the National Institute on Aging's Intervention Testing Program.These observations support the hypothesis that mitochondrial and metabolic dysfunction induced by Complex I deficiency may be a key component of biological aging as well as mitochondrial disease.Furthermore, we propose that the Ndufs4-/-mice provide an affordable testing ground for candidate longevity interventions.

DELETION OF THROMBOSPONDIN-1 PRESERVES HEMATOPOIETIC STEM CELL HEALTHSPAN DURING AGING
Pradeep Ramalingam 1 , Michael Gutkin 2 , Michael Poulos 2 , and Jason Butler 2 , 1. University of Florida,Gainesville,Florida,United States,2. Hackensack University Medical Center,Nutley,New Jersey,United States Aging is associated with defects within blood stem cells, termed hematopoietic stem cells (HSC), including a loss of their self-renewal potential and a skewed differentiation towards myeloid lineages at the expense of lymphoid cells.Collectively, these HSC defects manifest as anemias, poor response to vaccines and an increased incidence of myeloid neoplasms in older adults.Unlike other somatic stem cells, aged HSCs have been shown to be refractory towards established anti-aging interventions including caloric restriction, exercise, parabiosis and plasma transfer.Thrombospondin-1 (TSP1) was initially discovered as an anti-angiogenic molecule, and recent studies have identified that TSP1 promotes age-related pathologies including chronic inflammation, reactive oxygen species (ROS) generation, and mitochondrial dysfunction.Notably, each of these TSP-1 regulated processes have been shown to critically influence HSC biology, particularly in the context of aging.However, whether TSP-1 directly regulates HSC activity remains unexplored.Here, we sought to determine whether TSP-1 is essential for HSC development, and whether blocking TSP1 signaling could ameliorate age-related HSC defects.Utilizing murine models, we demonstrate that TSP-1 is dispensable for normal HSC development and hematopoiesis.We show that deletion of TSP-1 is sufficient to preserve HSC fitness during aging, as evidenced by preservation of youthful self-renewal potential and balanced lineage reconstitution during serial HSC transplantation assays.Mechanistically, we identify that TSP-1 adversely impacts mitochondrial metabolism within HSCs, and show that loss of TSP-1 prevents the age-related decline in HSC mitochondrial membrane potential.Our findings identify TSP-1 as a pro-geronic factor that can be targeted to preserve HSC healthspan.

A FAT-PROMOTING BOTANICAL EXTRACT ARTEMISIA SCOPARIA EXERTS GEROPROTECTION IN C. ELEGANS
Bhaswati Ghosh 1 , Hayden Guidry 2 , Maxwell Johnston 1 , and Adam Bohnert Like other biological processes, aging is not random but subject to molecular control.Natural products that modify core metabolic parameters, including fat content, may provide entry points to extend animal lifespan and promote healthy aging.Here, we show that a botanical extract from Artemisia scoparia (SCO), which promotes fat storage and metabolic resiliency in mice, extends the lifespan of the nematode Caenorhabditis elegans by up to 40%.Notably, this lifespan extension depends significantly on SCO's effects on fat; SCO-treated worms exhibit heightened levels of unsaturated fat, and inhibiting Δ9 desaturases, which oversee biosynthesis of monounsaturated fatty acids, prevents SCO-dependent fat accumulation and lifespan extension.At an upstream signaling level, SCO prompts changes to C. elegans fat regulation by stimulating nuclear translocation of transcription factor DAF-16/FOXO, an event that requires AMP-activated protein kinase under this condition.Importantly, animals treated with SCO are not only long lived but also show improved stress resistance in late adulthood, suggesting that this fat-promoting intervention may enhance some aspects of physiological health in older age.These findings identify SCO as a natural product that can modify fat regulation for longevity benefit and add to growing evidence indicating that elevated fat can be pro-longevity in some circumstances.With age, senescent cells accumulate in various tissues where they contribute to loss of tissue homeostasis, aging, and age-related diseases through their inflammatory senescenceassociated secretory phenotypes (SASPs).Senotherapeutics able to selectively eliminate senescent cells, termed senolytics, or suppress the detrimental SASPs, termed senomorphics, have been demonstrated to improve age-associated comorbidities and aging phenotypes.To discover novel senotherapeutics translatable to promote healthy longevity, we conducted a drug screening of diverse natural products based on the characteristic senescence-associated β-galactosidase activity.Several fucoidans from different brown seaweed were found to exhibit potent senotherapeutic activity.Fucoidans are long-chain sulfated polysaccharides found in various species of brown algae including seaweed.The best senomorphic fucoidan was able to suppress senescence in cultured senescent fibroblasts, in ex vivo human tissue explants, and in vivo in mouse models of natural and accelerated aging.Specifically, fucoidan reduced markers of cellular senescence and SASP in senescent mouse and human cells.Acute treatment of the fucoidan in naturally aged mice reduced tissue senescence, especially in the kidney and lung.Chronic treatment of the fucoidan in Ercc1-/Δ progeria mice attenuated composite aging symptoms and extended healthspan.Interestingly, preliminary mechanistic studies demonstrated that fucoidan can improve non-homologous end-joining-directed DNA damage repair and increase the mono-ADP-ribosylation activity of SIRT6, suggesting a relationship between cellular senescence, DNA repair, and SIRT6 signaling pathways.Collectively, fucoidans were identified as novel senotherapeutics with translational potential for reducing cellular senescence, ameliorating age-associated phenotypes, and extending healthspan as well as able improve DNA repair pathways through modulation of SIRT6 activity.

EFFECT OF L-VALINE TREATMENT ON SIRTUIN (SIRT1 AND SIRT2) ISOFORMS
Shakshi Sharma, Xiaomin Zhang, Gohar Azhar, and Jeanne Wei, University of Arkansas for Medical Sciences (UAMS), Little Rock, Arkansas, United States L-valine is one of the essential branched-chain amino acids (BCAAs) required for synthesis of proteins in human body.It promotes muscle growth and tissue repair and is important for immune function.Recent data indicate that BCAAs can activate sirtuins expression and elevate mitochondrial biogenesis and fatty acid oxidation in both adipocytes and myotubes thereby increasing life span.Sirtuins are a conserved family of proteins, play a critical role in maintaining metabolic health by deacetylating many target proteins in numerous tissues, and regulate mitochondrial function and the aging process.Due to multiple effect of sirtuins on aging, we sought to determine whether the addition of valine might enhance sirtuin gene expression.We utilized the C2C12 skeletal muscle cell line grown on physiological normal glucose (100mg/dL) media.The cells were treated with two different concentrations of valine (0.5 and 1.0mM) for different time intervals (18 and 24).Gene expression of sirtuin 1 (SIRT1) and sirtuin 2 (SIRT2) isoforms were determined by RT-PCR.The results showed increased expression of the sirtuin gene isoforms after treatment with valine.Relative expression varies with in different isoforms of SIRT1 (v1 and v2) and SIRT2 (v1, v2 and v3).Among all, SIRT1 v1 and SIRT2 v1 showed maximum expression as compared to the other isoforms used in the study.Our study showed that adequate supplementation of L-valine enhanced sirtuin gene expression, which may promote healthy muscles and healthy aging.

LOSS OF HYPOXIA SIGNALING IMPAIRS RESPONSE TO AEROBIC EXERCISE IN AGED MICE
Indranil Sinha 1 , Yori Endo 2 , and Mehran Karvar 1 , 1. Brigham and Women's Hospital,Boston,Massachusetts,United States,2. Harvard Medical School,Boston,Massachusetts,United States To assess the differential effects of exercise with age, Young (Y, 10-12 weeks) and Old (O, 23-25 months) mice were subjected to regimented treadmill running or no regimented exercise.Y, trained mice experienced a significant increase in maximal distance running, maximal speed of running, and lean muscle mass in comparison to age-matched, untrained controls.O mice did not improve significantly in any of these measures following training.Transcriptome analysis of gastrocnemius from Y mice demonstrated differential regulation of 120 genes with exercise.None of these genes were similarly regulated in the O group.Genes most upregulated following exercise in Y mice were direct targets of the hypoxia signaling pathway.Immunoblotting demonstrated that aryl hydrocarbon receptor nuclear translocator (ARNT), a critical regulator of hypoxia signaling, increased 3-fold with exercise in Y mice, but this increase was absent in O mice following exercise.To assess whether this loss of ARNT in O muscle impaired the exercise response, we generated a mouse with inducible, skeletal muscle-specific knockout of ARNT (ARNT muscle (m) KO).Following regimented exercise, ARNT mKO mice did not improve maximal distance running, maximal running speed, or lean muscle mass in comparison to untrained ARNT mKO mice.Littermate, age-matched ARNT wild type mice increased significantly in all of these measures following training.Administration of ML228, an ARNT agonist, increased maximal running distance and speed in response to exercise training in O mice.These results suggest that restoration of ARNT and hypoxia signaling may restore the physiologic response to exercise in aging.