LSM 3217 Notes PDF

Lecture I Hypothesis of aging : Program theories YS Damage theories > - Fundamental limitation...

Lecture I Hypothesis of aging : Program theories YS Damage theories > - Fundamental limitation > - Deterioration accumulation Telomere shortening rate > 1. Telomere attrition - predicts species life span 1. Mitochondrial dysfunction ↳ end problem generic DNA & of mito big esp in muscle ) rep , proportion y shut degradation present I shorten when , telomerase activity culls , is down in most tissue - : aging in large amt poor enzyme activity , V will cause accumulation of ROS. 2 Sem cell exhaustion from breathing--bad & stem cell undergo assymetric division love differentiated ,. 2 Chronic inflammation ↓ another remain as tell) stem ↳ immune cells triggered aging BUT -> both differentiate when sick aging 1 hand to get them suppressed > - irreversible process controlled by internal back to resting stage lack of factors , can only slow down. 2 Bad halits eg diet. , cause increase sleep , overtime accumulation Hepatic satellate immune cell activation/ bad population proliferation/ : - cells (HSC) differentiation > reversible process affected by external - ↓ factors , cam be rejuvenated lead to immunosenescene /detoriation ey, supplements may help of immune system) in older ppl cuz immune cells used up Telomere · Length measurement ↳ Southern blotting get based - uses unique telomere repeat sea Time unsuming - - tedious ↳ quatitative PCR LQ-PCR) genaue wide sea - know exact position of telomere to get primer time than above consuming the less - - Fluorescent in Situ Hybridization (FISH) - use flow cutometry forum probe , shorter length , - only 2 mins ! lesser intensity  indicator of which type of tissue biopsy does not accurately show telomere length as an aging ? ↓ skeletal muscle ↳ don't divide , amt of muscle fibre does not increase , only gets repaired by : residential stem cell butactivity low ↓ leukocyte , skin fibroblast divides Enhance telomere length to reverse aging ? X can lead to cancer - usually telomere is re-activated in most cancer cells Cell cycle checkpts - Gl : building blocks of DNA & proteins present sufficient energy , B G2 : DNA replication proteins , & organelles duplication success ↳ M : lined up in centre for segregation Oncogene CDK & & growth signal that promotes cyclin activity Tumor suppressor deck CDK & ↳ checkpt system to cyclin activity ↳ drives cellular senescence > degrading p53 gets cancer - , mice > - increasing stability of p83 , resisting degradation cancer , free but die early cuz senescence cell don't proliferate well: life span still shortened ↳ mutation led to hunched back mice & muscle atrophy Senescence cell ~ stop dividing but don't die ↳If immune cells cannot clean senescence cell , cytokine will continue to be secreted , triggering cells to be proliferated , wasting resources > senescence - impt for reconstruction of tissue : · & senescence marker is transient activate during development / > need cytokine for proliferation of cells for repair - :. it depredation of senescenceall , wound healing affected Stem cell & senescene cells experiment ↳ normally , stem cell undergo unsynchronised proliferation ↳ BUT when stem well undergo senescence , checkpt disappears BrdV inserted into replicating DNA , to visualize cell proliferation ki67 present when cell is in the well cycle (G1. G2. S , Must GO) - cell proliferation marker stem well undergo proliferation free older > Expshows more in mice A BrdU ki67] + Chigher & B E p16 & p21 senescent marker to detect cell cycle older arrest is present in mice even tho more cells in cell cycle. D - old stem well 2 loses ability to differentiated integrate to skeletal muscles What distinguishes beneficial effects from damaging effects of cellular senescence ? Beneficial - transient (temp) senescence damage - chronic senescence (eg - long live inflammatory respence) etc. Lecture 2 What cellular components cannot be degraded by autophagy - lysosomal system ? ~ Genomic DNA ↳ start of autophagy -lysosome initiated from - ER , lipid membrane by won't budding off ER & migrate further away from nuclei. to go nuclei cannot degrade : what conditions could promote autophagy ? physiological ↳ all kinds of stress eg. starvation 4 starvation- > nutritional pathways stop , all energy focused on surviving & cleaning infections & damage thus energy system shut down thus autophagy needed as it will degrade damaged products & other things for cell to to provide energy survive Autophagy regulation High AMPK = turn on autophagy , High MOR21 = shut down autophagy [Inhibitor] Tsc Y stimulates > autophagy - X Queh Lactivator] autophagosome can be visualizes - membrane by LC3 on > - No nutrients , MTORCI shut down AMPK activated ATPL ADPU AMPK , , , :. high insulin unz stimulate independent glucose transport > No glucose ULK protein kinase phosphorylated - , inhibits AMPK > - UIK1 Sev317 & 777 phosphorylation required Phos UK ser257 > - mTORC inhibits ULKI binding to AMPK > - more more dominant than Ampk > - Rapa inhibits mTOR21 activity > Rheb special activator that localizes on found some cytoplasmic mTORC in , region & signalling factor store nutrients & an from food conjugate Isosome on membrane to activate MTORCI  when starving : > - Proliferation cells (tumor cells) prefer glycolysis cuz subproducts formed will did in growth > - But norm cell prefers using mito respiration one more Atp produced using lesser glucose - more efficient Dwarfism on liver ~ ↳ Laron syndrome - deficiency in growth hormone receptor , cannot properly use hormone - normal or high levels of growth hormone but low levels Fit of insulin-like growth Factor-1 (IGF-1S promotes growth of braes & tissues 212 lesser receptor:· To compensate , pituitary gland produces more growth hormone the go to liver but lesser receptor, lesser IGF-1 produced : - deficiency - less susceptible to age-related disease , but more effected by social impacts - normal or improved levels of cardiovascular disease risk factors Diet diet-30% Suac intake Joists ↳ Okinawa - lover caloric consumption > - But change in diet2n2 Tourist influence leading to decreasing lifespan & move to Brazil also ↓ Ifespan (WW2) ↳ In older adults- Inability to eat - - Illness Iceeving food preferences appetite 3 malnutrition Evolutionary trade off ↳ fitness benefit of trade 1 and cost of trade 2 balances out eg. higher repor but shorter lifespan Lecture 3 Which kinase activity is activated by ATP deficiency ? VAMPK1 4) ATP low , AMP & ADPT , cuz end product cannot be made : ratic will stimulate AMPK :. When mito got problem triggering AMPK Amino acid direct activator of MiORC MTORCI - fed late in life , can extend lifespan ↳ But male & female don't the same respond & = FSR rate of leucine measures incorporation in muscle protein ↑ resence ofuutrients increases FSR :· S6K/ dysregulation affects muscle protein synthesis & old not as significant as young chz develop anabolic resistance] D > - activate cleavage caspaces regulates i-apoptosis Muse mTORC activation lead to degeneration in human Skeletal musche Diabetes · Type 1 : Insulin deficiency failure insulin due lost of cells liver - of pancuas to produce enough to pancreatic : secreted other have glucose won't take glucose if no insulin our want cells to , muscle also don't take glucose. high blood glucose concentration · Type 2 : Insulin resistance ↳ downstream signalling pathway blocked => Tissue (skeletal muscle) Failure to from blood respond to insulin to take up glucose Stage ) 1. Akt relocates GLUT4 to membrane but when insulin resistance. GLUTY cannot relocate stage 2 2. Insulin label increase in strum cur of feedback stage 3 3. Insulin B cells overworked due to overproduction :: apoptosis so pancreas ⑳ cannot produce insuline :· in the end may need insulin shot Circadian rhythm ↳ muscle clock regulates muscle insulin sensitivity via protein levels & rembrace translocation of Go + 4 ↳ Time restricted feeding prevents body weight gain , improves glucose tolerance Circadian misalignment ↳ InsufficientSleep > energy expenditure higher ouz lesser energy conserved - > - Insufficient sleep leads to positive energy balance which can be due appetite energy intake reight gain to increase in to increase.. > higher risk of developing hypertension& type 2 diabetes - ↳ cardiac alignment & caloric restriction (fasting deating & right timing) shown to increase lifespan in male mice untrients & Which kinase is activated by queath factor is responsible for promoting protein synthesis ? UMTORCI What is the fundamental problem of aging at cellular level ? ↓ lose sensitivity to environmental ches X decrease cell cycle checkpt ability - higher pl6 d p2 present * gain appetite - cell do to listen not appetite problem X increase self-depredation ability - norm condition not increased only when starying  Lecture 4 adventifia dilation & contract present (endothelial c structure of vessels value / Tunica Tunica ↑ lumen intima ) media (smooth muscle Artery & Vein : > > · - - cell & elastic fibres) > - externa (collagen fibers) ~ elastic contains newe , E yasa vasorunt (small capillaries that brings Fibroblast immune that area ( , cells nutrients to · Capillary : lumen> endothelial > - basement membrane Ene smooth muscle cut du contract as much Arteries : > - Elastic arteries Caorta , carotid , common iliac) 4 inactive in yasoconstriction 4 reservoirs - a receil blood ejected from heart pressure expand as > - muscular arteries (radial , splenic , femoral) ↳ deliver blood to organs ↳ active in vasoconstriction- more sweeth musche cell > - Artericles (alloverbody) Econtrol flow into capillary bed-easodilation of constriction  Age associated arterial phenotypes ↳ endothelial dysfunction - last of balance - oxidant , Vaso constrictor , pre inflammatory & prothrombotic - Nitric oxide reduction - oxidative stress (more oxidative agent produced) > - In aged endothelial cells , eNos produce Or rather than NO. : reduce radicals CONOO-) leads No , more potent free form which to increase oxidative stress , damage macromolecules - less of endothelial cell function = > less dilation ofvessels : more constricted vessels ↳ Arterial stiffness - affects recoild extension , affecting blood flow ↓ - media thicken , adventifia increase in collagen deposit , no blood can be stored in reduce elastin content & increase proinflammatory cells acuta during systole dont - elastin production rily increase in Ifetime · : during diastole & flow through ofblood macrophage & neutrophils ↑ degredation prod of collagen butcollage 4 to stops compensate + more i rigid Bad aut not equal &.. stiffening & elastin & fragmentation in old age Cutinuous flow fraying systale-heart contracts out to pump blood diastole - heart relax aft contraction out of heart strake vol-vol of blood pumped Determine Vascular age · Measure carotid intima - media thickness ↳ men faster rate of thickening that women (proce to 24Ds) but women off neuspause , rate also increases · Arterial stiffness thre Pulse wave velocity ↳ left ventricle > - donta + body & calculate speed of pulse wave from carotid to femoral ↳ stiffer = faster Currigidso less recoil - blood :· move Easter Lecture 5 ↳ ONCO-contributes to vascular aging cytotoxic effects > - > - inflammatory pathways 4 Inflammaging - chronic , Sterile , low grade inflammation (been there but lo) - can be seen from increase in circulating C-reactive protein (CRP) , proinflammatory cytokines ↳ related to aortic stiffness - increase in NF.B activity implicated in arterial dystraction ↳ inhibition improves acrfic stiffness 4 Ros can increase NFRB contributes to of vascular diseases pathogenesis - I exidative stress inflammation - (ECM) ↑ T > - Ros can lead to changes in extracellular matrix , collagen & reduce elastin + stiffness ↳ cellular senescence - irreversibleall cycle arrest induced by2 major Tumor pathways ~ suppressor > - p831p21 pathway > - P16/pRB pathway - expression of senescence mackers & proinflammatory exidant senescence associated Secretary phenotype (SASP) T - spread vascular inflammation & oxidative stress to healthy als via SASP premating chronic low grade inflammation exidative & stress in ren-senescent vascular cell micke is key initrator ↳ SIRT1- transcriptional regulators stress resistance provides - - aging reduces SIRTI expression & activity - endothelial dystauct? & arterial stiffness Rejuvenation strategies ~ Caloric restrictions ↳ in mouse : ↑ endothelial vasodilation & NO bioavailability in large artery stiffness ↳ BUT humans not sure · Systemic factors But dk what are these factors ↳ anti geronic circulating factors ↳ experiment : heterochronic parabiosis > - acnnect circulatory system of Imice & microvascular ↳ can rejuvenate endothelial function in large urteries network architecture & blood factors rejuvenaty rather than blood cells play role in Clear · senescence cells Not tested in humans ↳ Treatment is senolytics > apoptotic pathway - ↳ gnetic manipulation & removal of pl6 positive cells in aged mice uTor · manipulation using Rapamycin ↳ delayed development of agerelated pathologies 4 associated: many related to processes aging helps 4 reduce oxidative stress in old mice Fendothelia dilation & reduction of NO ↳ downregulate inflammatory cytokine i Batelastin ot 4 decrease aortic collagen > - arterial stiffness reduce ↳ switch of smouth muscle cells & synthetic to contractile :· lessECM produced , less stf SIRT I expression · ↳ prevents age related decline in endothelium dependent vasodilation 4 prevents acutic stiffening maintain balance of collagen ↑ prevents adverse struct changes in arteries , ↳ nicotinamide monodectide (NMN) ↑ SIRT activation ↳ reverse age related aortic stiffeningd normalize aortic collagen & elastin content in old mice ↳ redince aortic stiffness in middled oldwice ↳ possibly increase activation by resveratrol & SRT-1720 Ismall molecule) => Need more research but got potential  Lecture 8 measured using movement capacity Lifespanthhsp , an indend allow for a longer lifespan (mice lives longer but the rate of movement still declines as in in WT mice. 3 14FR essential for balance needed cellular growth E Muscle types : exidative - use mito to generate ATP But (glucose Preferlipid te) ~ lycolytic use glucose as energy mesouce. man, - - but not use mito , incyto : I fast 9 Incose to 2 ATP BUT a lot of enzymes in cyte :. Xu mito activity still y fast (mito will be longers differentiated in the - newly move Myonuclei labelled mCherry man > - on centre of myofiber mature mycnules distance themselves membrane surrounding muscle fiber observed 6 skeletal muscle muscle Fiber > myofibril - > - I contains multiple repeats of site active myosin internete& sucremere calcium acting myosin > when - present , slides across one another > - contraction > - A in length of myofibril produces contractive forces > - theoretically : more sacrament = more strength which macromolecule old not be stored in cells ? ~ proteins=> made to be used.. won't store X carbo - stored as glycogen in skeletal muscle for use by typeIl muscles- those who do resistance exercise alot muscle a stone will adapt temporarily BVTdiabetic ppI also have Bad good X lipids- stored as triglyceride good Marathon runner have more type I muscles/oxicative) which uses lipids as energy resource rather than glucose when aw run adaptation - : , extra lipid stored in muscle ; glucose save temp for brain bad - Obese /diabetic may have infiltration of triglyceride into skeletal muscle which can cause inflammation Assumption : protein synthesis rate > degradation = hypertrophy - aim to increase anabolism (protein synthesis) a suppress catabolism (protein degradation) stress BUT sustained anabdic signaling increases protestasis ↳ Basically if protein synthesis & suppress increase proteasome& autophagy quality control decreases, , there will be accumulation of damaged proteind & organelle = > atrophy weakness Type I fiber - more capillary che need oxygen > - more satellite cell Fiber-moreffected older when vascular Type /I when system effected cuz got less capillaries causing reduction in satellite cells onc less capillaries then less niche for satellite cells to nest Innervation of myofibers ↳ muscle spindle 5 interact Sensory neuver ↳ action potential into presynaptic neuron , influx of cart - cast causes slidinga notin + myssin :· contraction MRI allows visualization of fatty infiltrate Question air healthy. honey comb struct TUG functional mobility > : - balance + walking ability + - full risk walk Sm wise from chair ,. turn 180, walk 3m , turn 180 , sit - When capillary density reduced , distance of satellite all increases - breaks muscle fiber connectivity  The more fut , the lesser the fut subutaneous activity muscle 1.Staluse t Muscle hypertrophy mostatin mutation > absence of mature mystatin - ↳ inhibits protein synthesis & activate protein degredation AKT 4 probably targets AkT activity - wo mystatin. hyperactive , proteasore downregulated Failed clinical trial of Myostatin inhibition ↳ nor test on old mice -old muscle cells diff from young I but female all tests on male mice sacropenia more prevalent in  Lecture 9 what do re lose during aging ? What triggers aging ? - sensitivity - to regulators - mTORC sensitivity accumulation of damage sensitivity ↓ don't - > - stop when supposed to - activity not as high to what it is supposed to be Sacropenia age related loss of muscle & strength, progressive mass - muscle atrophy d stone collagen d lipids - impt cuz first tissue to sacrifice when theres lack of nutrient the more myofibril that can innervate ~ is the more active motor neuron , - ↓ affects sucrevere activity - the more sacromere the more force one can produce > determines the aut of - ATP one can get aut of glycolysis & mito (metabolism decides strength linked to Autophagy of muscle fibers usually degenerative disease,n2 multiple checkpts to preventdamaged to rectify to prevent accumulation Isame is  of untritional status & for cell growth & mTURLI-key sensor eny stresses survival increase protecstusis stress ~ sustained activation drives muscle But mTORC aging NMJ (neuromuscular junction) alterations + micRI hyperactivation drives NMJ ↓ motor to skeletal muscle alterations ↳ neuvon leads to denervation (loss of neave supply) , in loss post synaptic myouudei increase , number of disconnected postsynaptic AChe stopped her for LA clusters > - 4EPBI activation/sok/ inactivation & restores aberant increase in protein synthesis from hyperactive mTORC1 ↳ suppresses cap-dependent translation. - ↓ protein synthes is ↳ restore mediated inhibition of ULK autophagy activity - wo elieving mtcRCI Jexpands -↑ autophagy , to damage protein , ↳ restores protein homeostasis in sacrepania mouse ↓ damaged mito lysosomal degredation capacity in TSCImKO muscle ↳ denervation response reduced in background (NCAM-denervation marker , Laminin - Sacrolemona marker) Behances muscle regeneration Upregulated MTORC signals muscle aging laying causes reduction in sensitivity of MTORC to external ches 4 PEBPI endance protein - turnover > - improves quality control inhibits of ↳ proteasore & autophagy protein Synthesis needed for optimal growth, 3 dynamic MTORL regulation is muscle Herworking causes loss in sensitivity to eny cues still get more... Lecture 10 Primary prevention - stop chronic disease by they happen Secondary - has risk , try to prevent worsening getting affected - Tertiary try to prevent other organs from Physical activity- > Any bodily movement produced by contracting skeletal muscle ↑ energy level above resting - eg. chores , walking , recreational Exercise - subset of PA structured of , planned , , repetitive - goal of maintain fitness & health improving physical for functional Cardiorespiratory fitness (VOr max) is the major predictor capacity Maintaining high degree of cardiorespiratory fitness = greater functional reserve delay premature onset of frailty = 12-6 E increase during contraction - usually pro-inflammatory but when released from skeletal muscle contraction , induce anti-inflammatory properties by causing cuscade of anti-inflammatory proteins to be activated 4 If released from endothelial cells & basal activity level -> Bad !  release hormones directly into ~ Contracting Skeletal muscle - endocrine organ circulatory system > - How fast person ages is influenced by breakdown & homeostatic pillars ↓ produces endogenous levels of anti-oxidants > - upregulation of catalase > ROS the does produce Ros well but increase upregulation of quench as - , defense mechanism  Metabolic flexibility- ability of Skeletal muscle to a fuel used for substrate oxidation ↳ primary site of metabolic events is skeletal muscle If unable to ↳ regulate btw glucosea lipid metabolism => characteristic of chronic disease Cobesity - type 2 diabetes) Constant activation of immune system - constant release of pro-inflammatory factors /cytokines + insufficient release of of where anti-inflammatory cytokines > - insufficient resolution inflammatory cuscade Dysfunctional adipose tissue leads to cytokine & chemokine secretionE> inflammation Life long exercisers have 2x lower inflammation than non-exercises - 11-6 levels lover  vi > - of no damage in muscles : - low TNF & - "T - entiblunt inflammatory pre effects of +NEa producem more cannot TNF-X produced an at a damage to muscle when exercise FGF21 similar role insulin into muscle > to helps to bring glucose - - produce during exercise to help glucose - metabolism Mitochondrial biogenesis - improves muscle energy production & efficiency oxidative Endurance training - improves mito capacity , ATP phos , biogenesis I - type I muscle Resistance - typell muscle fiber size & aty t , with exidative capacity ↳ fast twitch > - aging leads to a lot of type /1 lost Concurrent training Best comparing old a healthy individuals young ↳ ye proteins expressed differently - 11 expressed differently in age - 20 aft exercise 11 exercise type - ↳ with age , there may be a decrease in ability to mobalize or release certain kinds of cytokines Better intensity exercise to start or low cuz there will be products of pro-inflammatory cytokines - may not be able to regulate in aged ppl esp is underlying inflammation why disease +  Lecture I Aging- > Brain undergo atrophy Disease : Alzheimer's 4 brain shrink selectively affected & reduce brain function hippocampus degenerates > - > - Dendritic synaptic structure ↳ less complex in old dendritic spine in old ↳ reduction in ↳ neuronal response reduce white matter > - white matter lesions correlate to decline memory myclimated > - anterior white matter preferentially degraded in aging a xous Cre/Lox > - cre (recombinase) recognises lox gives flanking target gene > - causes deletion of target gene Induciblecre > post translational control - ~ stay in cyfesal > - without 4-oH + no activation of an will > ↓ 4-oHt bind to estrogen receptora recombinase - , move into nucleus to delete gene matter -white Myelin > degeneration links to age-related deficits in - memory > - found in mature oligodendrocyte from - stem cells (OPCs) that can undergo renewal , OPCs found throughout brain to retain regeneration capacity  > - NG2 (CSPG4) is a marker for OPG , become digo turn off , renewal declines ability of OPCs to make new oligo > - o age , is deminished > - decrease in myelin - decrease in memory , but learning still okay ↳ for formation Olig2-critical OPCs > - marker for digo > - Oligh KO , mature oligo reduced > - KO inhibits myelination a impairs memory ↳ Clemastine > - increase myelination > improve memory - increase decrease ↳ Glial > - aging - microglia gene activity & neuver gene activity => Bad for neuvoual health > - activated microglia trainsastrocytes to become killer for oligo & neurons (neurotoxic reactive astrocytes ↳ induced ischemic stroke reduced blood flow to , brain , astrocyte active a kills neuvous ↳ inject (ps to nice to make NS think got bacteria infection to produce astrocytes ~ promote neuron repair , up regulate reurotrophic factors > - Ischemia - Pan + A2 astrocute It-1x > - LPS - Pan + Al astrocyte - sigual : , THE , C1q formation - ↳ Al astrocytes + do not promote synaptic no norm functions > - lose phagocytotic ability > - Induce death of neuvous & digo (don't kill Op(s) > - C3 (stain) + can be seen in human disease > - region specific (hippocampus strictum during aging) > - astrocytes more reactive during aging  Lecture 17 ALS lateral sclerosis => Amyotrophic Clinical Signs : ↳ paralysis without loss of sensation G from legs up o r from one side to the other ↳ deformation of limbs 3 Legs affected - standing a walking ↳ Bulbar systems speech a swallowing - ↳ Fast death within 3 progression , years Discovery : ↳ hardening of lateral columns in spinal cord of cells cells grey matter 6 in the grey matter only small not left in defermed & atrophied [ , ↓ maternuclei is cost of mater > - lost of signal to muscle > atrophy - neuvon ↳ write lateral column associated in spasticity > - Adult cuset neurodegenerative disease (45-60 yeardd) > - uppera lower motor neurc