Essential Physiological Differences Characterize Short- and Long-Lived Strains of Drosophila melanogaster

Aging is a multifactorial process which affects all animals. Aging as a result of damage accumulation is the most accepted explanation but the proximal causes remain to be elucidated. There is also evidence indicating that aging has an important genetic component. Animal species age at different rates and specific signaling pathways, such as insulin/insulin-like growth factor, can regulate life span of individuals within a species by reprogramming cells in response to environmental changes. Here, we use an unbiased approach to identify novel factors that regulate life span in Drosophila melanogaster. We compare the transcriptome and metabolome of two wild-type strains used widely in aging research: short-lived Dahomey and long-lived Oregon R flies. We found that Dahomey flies carry several traits associated with short-lived individuals and species such as increased lipoxidative stress, decreased mitochondrial gene expression, and increased Target of Rapamycin signaling. Dahomey flies also have upregulated octopamine signaling known to stimulate foraging behavior. Accordingly, we present evidence that increased foraging behavior, under laboratory conditions where nutrients are in excess increases damage generation and accelerates aging. In summary, we have identified several new pathways, which influence longevity highlighting the contribution and importance of the genetic component of aging.This work was supported by the European Research Council (260632 - ComplexI&Aging to A.S.); the Academy of Finland (252048 to A.S); the Biotechnology and Biological Sciences Research Council ( BB/M023311/1 to A.S.); the Centre for International Mobility (CIMO) (TM-12- 8391 and TM-13-8919 to N.G.); the Spanish Ministry of Economy and Competitiveness, Institute of Health Carlos III (PI14/00328 to R.P. and PI17/01286 to P.N.); the Autonomous Government of Catalonia (2017SGR696 and SLT002/16/00250 to R.P.); the Ministry of Education and Science of Ukraine (grant number 0117U006426 to O.L.); FEDER funds from the European Union (“A way to build Europe” to R.P.); and the Doctoral Programme in Medicine and Life Sciences of University of Tampere (to T.R). R.S is a Sir Henry Wellcome Postdoctoral Fellow funded by Wellcome (204715/Z/16/Z

7,8-Dihydro-8-oxo-1,N6-ethenoadenine: an exclusively Hoogsteen-paired thymine mimic in DNA that induces A→T transversions in Escherichia coli

14 pags., 9 figs.This work investigated the structural and biological properties of DNA containing 7,8-dihydro-8-oxo-1,N6-ethenoadenine (oxo-ϵA), a non-natural synthetic base that combines structural features of two naturally occurring DNA lesions (7,8-dihydro-8-oxoadenine and 1,N6-ethenoadenine). UV-, CD-, NMR spectroscopies and molecular modeling of DNA duplexes revealed that oxo-ϵA adopts the non-canonical syn conformation (χ = 65º) and fits very well among surrounding residues without inducing major distortions in local helical architecture. The adduct remarkably mimics the natural base thymine. When considered as an adenine-derived DNA lesion, oxo-ϵA was >99% mutagenic in living cells, causing predominantly A→T transversion mutations in Escherichia coli. The adduct in a single-stranded vector was not repaired by base excision repair enzymes (MutM and MutY glycosylases) or the AlkB dioxygenase and did not detectably affect the efficacy of DNA replication in vivo. When the biological and structural data are viewed together, it is likely that the nearly exclusive syn conformation and thymine mimicry of oxo-ϵA defines the selectivity of base pairing in vitro and in vivo, resulting in lesion pairing with A during replication. The base pairing properties of oxo-ϵA, its strong fluorescence and its invisibility to enzymatic repair systems in vivo are features that are sought in novel DNA-based probes and modulators of gene expression.MIT Skoltech Next Generation Program Pilot Grant (to J.M.E.); National Institutes of Health (NIH) [R01-CA080024 to J.M.E.]; NIEHS Center Grant [P30-ES002109 (to Center for Environmental Health Sciences, which provided access to NGS facilities)]; Skoltech (to T.S.Z.); MICINN [PID2020-116620GB-I00 to C.G.]; Ministry of Science and Higher Education Russian Federation [07515-2021-1049 to A.V.A. – synthesis and UV/CD studies]. Funding for open access charge: Skoltech.Peer reviewe

Unmarried couples in a long-term relationship

To diplomsko delo raziskuje individualne in družbene razloge parov, ki so v dolgotrajni zvezi, da se ne poročijo. Ljudje se vedno bolj odločajo le za skupno življenje brez poroke, saj jim ta ni pomembna za njihovo zvezo. Dovolj jim je, da imajo ljubezen, spoštovanje drug do drugega in da so si enakovredni. Tudi druge raziskave in teorije ugotavljajo, da se pari vedno manj poročajo zaradi tega, ker poroka ni več družbeno pričakovana, nima več tako velikega družbenega pomena, je zgolj neka formalnost – le podpisan papir. Pari tudi takrat, ko dobijo otroke, ne razmišljajo o poroki, saj brez nje popolnoma normalno funkcionirajo v tej alternativni družinski obliki, ne da bi to negativno vplivalo na otroke. K porastu neporočenih parov pa je pripomogla tudi pravna izenačitev zunajzakonske skupnosti z zakonsko. Prav tako pari menijo, da se s poroko njihova zavezanost in čustva do partnerja_ice ne bi popolnoma nič spremenila, zato jim tudi nič ne pomeni sklenitev zakonske zveze. V današnjem času pa je k odločitvi, da se ne poročijo, pripomogla predvsem ekonomska neodvisnost žensk, saj tako niso več odvisne od moževega dohodka. Iz empiričnih podatkov je tudi razvidno, da večini parom poroka sploh ni pomembna. Tako smo lahko priča vedno večjemu številu parov, ki si poroke ne želijo ne sedaj ne nikoli.This thesis explores individual and social reasons why couples who are in a long-term relationship, do not get married. People are increasingly choosing only for a life together without being married because this is not important for their relationship. It is enough that they love, respect each other, and that they are equal. Other studies and theories find that fewer and fewer couples get married because marriage is no longer socially expected, no longer has a big importance but is merely a formality – just a signed paper. Even when couples have kids, they still do not think about getting married because they function completely normally in this alternative family form without a negative impact on their children. The legal equalization to the married couples also helped the rise of the unmarried couples. Couples also believe that marriage will not change their commitment and feelings for their partner even slightly. Consequently, marriage means nothing to them. Nowadays, the economic independence of women contributed to their decision not to get married because they are no longer dependent on the husband\u27s income. From empirical data, we can see that for most couples marriage is not important at all. So, we can witness an increasing number of couples who do not want to get married now or ever

The importance of worshiping the Hindu Goddess Kālī: Salvation and liberation from death and the human ego

Magistrsko delo razišče in interpretira ter analizira pomen čaščenja hinduistične boginje Kali. Raziskovanje s pomočjo literature in virov se osredotoči predvsem na to, zakaj se verniki zatekajo k čaščenju te boginje ter ali lahko tako pridejo do osvoboditve od smrti in človeškega ega. Jih boginja lahko pripelje do osvoboditve? Prav tako analizira pomen ikonografije in upodabljanja boginje, ki smo jim priča skozi njene omembe v mitih in epih. Številni avtorji boginjo predstavljajo kot strašno, grozno in shujšano, ki domuje na območju upepelitve ali prebiva na robu hindujske družbe. Večina opisov boginji pripisuje shujšan videz, razmršene in spuščene lase, vse skupaj pa dopolnjujeta ogrlica človeških lobanj in pas odrezanih rok. Vedno je povezana s smrtjo, krvjo in uničenjem. Njeni zvesti privrženci jo častijo kot strašno in nenadzorovano, a po drugi strani jo nekateri pri čaščenju vidijo kot mati in sebe kot otroka. Številni romarji jo pridejo častiti in ji podariti darove v njeno sveto mesto Kalighat. Kali pa je več kot le boginja smrti in uničenja, saj vernikom pomaga preseči idejo smrti in tako najti svobodo ter odrešitev. Ravno odrezane glave ter roke označujejo odpoved in osvoboditev od ega, da lahko pridemo do končne odrešitve po smrti in tako presežemo smrt samo. Boginja nam pri tem pomaga in nas vodi, da se sprijaznimo s prihajajočo smrtjo ter se znebimo strahu pred njo.The master\u27s thesis explores, interprets and analyzes the meaning of the worship of the Hindu goddess Kālī. Research through literature and sources focuses primarily on why believers resort to the worship of this goddess and whether this can lead to liberation from death and the human ego. Can the goddess lead them to liberation? It also analyzes the significance of iconography and the depiction of the goddess we witness through her mentions in myths and epics. Many authors present the goddess as a terrible, horrible and emaciated woman who lives in the area of cremation or lives on the edge of Hindu society. Most descriptions attribute to the goddess a slender appearance, disheveled and loose hair, all complemented by a garland of human skulls and a belt of severed arms. She is always associated with death, blood and destruction. Her faithful followers worship her as terrible and uncontrollable, but on the other hand, some see her in worship as a mother and themselves as children. Many pilgrims come to worship her and give her gifts in her holy city of Kālīghāt. Kālī, however, is more than just a goddess of death and destruction, as she helps believers transcend the idea of death and thus find freedom and salvation. Severed heads and arms signify renunciation and liberation from the ego so that we can reach final salvation after death and thus transcend death itself. The goddess helps us in this and guides us to come to terms with the coming death and get rid of the fear of it

Mitochondrial ROS Produced via Reverse Electron Transport Extend Animal Lifespan

Increased production of reactive oxygen species (ROS) has long been considered a cause of aging. However, recent studies have implicated ROS as essential secondary messengers. Here we show that the site of ROS production significantly contributes to their apparent dual nature. We report that ROS increase with age as mitochondrial function deteriorates. However, we also demonstrate that increasing ROS production specifically through respiratory complex I reverse electron transport extends Drosophila lifespan. Reverse electron transport rescued pathogenesis induced by severe oxidative stress, highlighting the importance of the site of ROS production in signaling. Furthermore, preventing ubiquinone reduction, through knockdown of PINK1, shortens lifespan and accelerates aging; phenotypes that are rescued by increasing reverse electron transport. These results illustrate that the source of a ROS signal is vital in determining its effects on cellular physiology and establish that manipulation of ubiquinone redox state is a valid strategy to delay aging.This work was supported by the European Research Council (ERC Starting Grant to A. Sanz), the Academy of Finland (Academy Research Fellowship to A. Sanz and Postdoctoral Research grant to H.M.C), the BBSRC (Responsive mode grant to A. Sanz), the Centre for International Mobility (Postdoctoral fellowship to N.G.), the Medical Research Council (M.P.M), and the Spanish Ministry of Health and the Instituto de Salud Carlos III (FIS PI14-01962 to P.N.). Electron microscopy image processing was performed at the Laboratory of Electron Microscopy, University of Turku, Finland. We thank Dr Rhoda Stefanatos for help with editing the manuscript. The authors declare no competing financial interests.S

Random Copolymers of Lysine and Isoleucine for Efficient mRNA Delivery

Messenger RNA (mRNA) is currently of great interest as a new category of therapeutic agent, which could be used for prevention or treatment of various diseases. For this mRNA requires effective delivery systems that will protect it from degradation, as well as allow cellular uptake and mRNA release. Random poly(lysine-co-isoleucine) polypeptides were synthesized and investigated as possible carriers for mRNA delivery. The polypeptides obtained under lysine:isoleucine monomer ratio equal to 80/20 were shown to give polyplexes with smaller size, positive ζ-potential and more than 90% encapsulation efficacy. The phase inversion method was proposed as best way for encapsulation of mRNA into polyplexes, which are based on obtained amphiphilic copolymers. These copolymers showed efficacy in protection of bound mRNA towards ribonuclease and lower toxicity as compared to lysine homopolymer. The poly(lysine-co-isoleucine) polypeptides showed greater than poly(ethyleneimine) efficacy as vectors for transfection of cells with green fluorescent protein and firefly luciferase encoding mRNAs. This allows us to consider obtained copolymers as promising candidates for mRNA delivery applications

5‑Chloro-2′-deoxycytidine Induces a Distinctive High-Resolution Mutational Spectrum of Transition Mutations In Vivo

The biomarker 5-chlorocytosine (5ClC) appears in the DNA of inflamed tissues. Replication of a site-specific 5ClC in a viral DNA genome results in C → T mutations, which is consistent with 5ClC acting as a thymine mimic in vivo. Direct damage of nucleic acids by immune-cell-derived hypochlorous acid is one mechanism by which 5ClC could appear in the genome. A second, nonmutually exclusive mechanism involves damage of cytosine nucleosides or nucleotides in the DNA precursor pool, with subsequent utilization of the 5ClC deoxynucleotide triphosphate as a precursor for DNA synthesis. The present work characterized the mutagenic properties of 5ClC in the nucleotide pool by exposing cells to the nucleoside 5-chloro-2′-deoxycytidine (5CldC). In both Escherichia coli and mouse embryonic fibroblasts (MEFs), 5CldC in the growth media was potently mutagenic, indicating that 5CldC enters cells and likely is erroneously incorporated into the genome from the nucleotide pool. High-resolution sequencing of DNA from MEFs derived from the gptΔ C57BL/6J mouse allowed qualitative and quantitative characterization of 5CldC-induced mutations; CG → TA transitions in 5′-GC(Y)-3′ contexts (Y = a pyrimidine) were dominant, while TA → CG transitions appeared at a much lower frequency. The high-resolution mutational spectrum of 5CldC revealed a notable similarity to the Catalogue of Somatic Mutations in Cancer mutational signatures SBS84 and SBS42, which appear in human lymphoid tumors and in occupationally induced cholangiocarcinomas, respectively. SBS84 is associated with the expression of activation-induced cytidine deaminase (AID), a cytosine deaminase associated with inflammation, as well as immunoglobulin gene diversification during antibody maturation. The similarity between the spectra of AID activation and 5CldC could be coincidental; however, the administration of 5CldC did induce some AID expression in MEFs, which have no inherent expression of its gene. In summary, this work shows that 5CldC induces a distinct pattern of mutations in cells. Moreover, that pattern resembles human mutational signatures induced by inflammatory processes, such as those triggered in certain malignancies

Supplementary materials for the article "Essential physiological differences characterise short- and long-lived strains of Drosophila melanogaster"

Supplementary material for the article "Essential physiological differences characterise short- and long-lived strains of Drosophila melanogaster