{"id":3020,"date":"2021-05-15T22:37:31","date_gmt":"2021-05-15T22:37:31","guid":{"rendered":"https:\/\/seniorfitness.blog\/?p=3020"},"modified":"2021-05-15T22:37:31","modified_gmt":"2021-05-15T22:37:31","slug":"kendetegn-for-cellulaer-aldring","status":"publish","type":"post","link":"https:\/\/seniorfitness.blog\/?p=3020","title":{"rendered":"Kendetegn for cellul\u00e6r aldring"},"content":{"rendered":"<p>De seneste par \u00e5rtier er det for alvor g\u00e5et op for videnskaben, at det faktum at vi \u00e6ldes ikke kan tilskrives en enkelt \u00e5rsag, men at der er flere mekanismer p\u00e5 spil.<\/p>\n<p>I et nyligt indl\u00e6g om aldringsforskeren David Sinclair og den bog han fik udgivet i 2019 n\u00e6vnte jeg kort, at der findes et s\u00e6t kendetegn, der beskriver baggrunden for aldring.<\/p>\n<p>Disse s\u00e5kaldte hallmarks (et lignende s\u00e6t hallmarks er benyttet til fx at beskrive kr\u00e6ft) er defineret af forskere i et fors\u00f8g p\u00e5 at forklare de molekyl\u00e6rbiologiske mekanismer, der ligger til grund for at vi bliver gamle og til sidst d\u00f8r af det. Dette s\u00e6t af hallmarks er samtidig en to-do liste for de forskere, der har ambitioner om at bremse aldring. Kompleksiteten af de enkelte punkter p\u00e5 denne liste er dog i mange tilf\u00e6lde s\u00e5 stor, at en forskergruppe ofte v\u00e6lger at fokusere p\u00e5 et enkelt hallmark.<\/p>\n<p>For de nysgerrige omfatter de g\u00e6ldende aldrings-hallmarks pt 9 punkter:<\/p>\n<ol>\n<li>Genomisk ustabilitet<\/li>\n<li>Telomer-nedbrydning<\/li>\n<li>Epigenetiske forandringer<\/li>\n<li>Tab af proteostasis<\/li>\n<li>Dereguleret f\u00f8lsomhed for n\u00e6ringsstoffer<\/li>\n<li>Mitochondriel dysfunktion<\/li>\n<li>Cellul\u00e6r senescens<\/li>\n<li>Udtr\u00e6tning af stamceller<\/li>\n<li>\u00c6ndring i cellul\u00e6r kommunikation<\/li>\n<\/ol>\n<figure id=\"attachment_3024\" aria-describedby=\"caption-attachment-3024\" style=\"width: 630px\" class=\"wp-caption aligncenter\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" data-attachment-id=\"3024\" data-permalink=\"https:\/\/seniorfitness.blog\/?attachment_id=3024\" data-orig-file=\"https:\/\/i0.wp.com\/seniorfitness.blog\/wp-content\/uploads\/2021\/05\/The_Hallmarks_of_Aging.jpg?fit=931%2C888&amp;ssl=1\" data-orig-size=\"931,888\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;1&quot;}\" data-image-title=\"The_Hallmarks_of_Aging\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/seniorfitness.blog\/wp-content\/uploads\/2021\/05\/The_Hallmarks_of_Aging.jpg?fit=931%2C888&amp;ssl=1\" class=\"wp-image-3024\" src=\"https:\/\/i0.wp.com\/seniorfitness.blog\/wp-content\/uploads\/2021\/05\/The_Hallmarks_of_Aging.jpg?resize=630%2C601&#038;ssl=1\" alt=\"\" width=\"630\" height=\"601\" srcset=\"https:\/\/i0.wp.com\/seniorfitness.blog\/wp-content\/uploads\/2021\/05\/The_Hallmarks_of_Aging.jpg?w=931&amp;ssl=1 931w, https:\/\/i0.wp.com\/seniorfitness.blog\/wp-content\/uploads\/2021\/05\/The_Hallmarks_of_Aging.jpg?resize=300%2C286&amp;ssl=1 300w, https:\/\/i0.wp.com\/seniorfitness.blog\/wp-content\/uploads\/2021\/05\/The_Hallmarks_of_Aging.jpg?resize=768%2C733&amp;ssl=1 768w\" sizes=\"auto, (max-width: 630px) 100vw, 630px\" \/><figcaption id=\"caption-attachment-3024\" class=\"wp-caption-text\">Hallmarks of Aging (fra <a href=\"https:\/\/www.frontiersin.org\/articles\/10.3389\/fendo.2018.00258\/full\">Rebelo-Marques et al<\/a>)<\/figcaption><\/figure>\n<p>Som det kan ses af listen omfatter alle punkterne molekyl\u00e6rbiologiske mekanismer, som f\u00f8rer til, at celler \u00e6ndrer adf\u00e6rd.<\/p>\n<p><em>Genomisk ustabilitet<\/em>: Akkumulering af skader p\u00e5 DNA i kernen (og i mitochondrier) kan f\u00f8re til at cellen ikke l\u00e6ngere fungerer optimalt. <em>Telomer-nedbrydning<\/em>: Afkortning af telomerer til en kritisk l\u00e6ngde efter gentagne celledelinger kan bidrage til f\u00f8rn\u00e6vnte genomiske ustabilitet og kan bremse videre celledeling. <em>Epigenetiske forandringer<\/em> omfatter \u00e6ndringer i s\u00e5kaldte methylerings- og acetyleringsm\u00f8nstre mm, hvilket kan \u00e6ndre programmet for hvilke gener der skal udtrykkes og hvilke der skal v\u00e6re slukket, hvilket kan p\u00e5virke cellens oprindelige identitet. <em>Proteostasis<\/em> beskriver en celles evne til at opretholde en balanceret opretholdelse af velfungerende protein. Et tab af denne balance kan medf\u00f8re en akkumulering af misfoldet og fejlfungerende protein i cellen. <em>Dereguleret f\u00f8lsomhed for n\u00e6ringsstoffer<\/em>: Ved overskud i tilg\u00e6ngelighed af n\u00e6ringsstoffer vil en celle typisk stimuleres til at vokse og dele sig, mens et underskud vil f\u00e5 cellen til at fokusere p\u00e5 vedligeholdelse og reparation. <em>Mitochondriel dysfunktion<\/em>: Mitochondrier leverer energien til hovedparten af de cellul\u00e6re processor, som foreg\u00e5r i kroppens celler. Undertiden dannes ogs\u00e5 s\u00e5kaldte reaktive ilt-radikaler (ROS, reactive oxygen species) i processen, hvilket kan lede til skader p\u00e5 cellen inklusive mitochondrierne selv, hvis niveauet bliver for h\u00f8jt. <em>Cellul\u00e6r senescens <\/em>fremkaldes hos celler, der har opn\u00e5et deres maksimale antal celledelinger og som g\u00e5r i st\u00e5 uden at bidrage mere til fornyelse eller v\u00e6re til nytte. I stedet for at g\u00e5 til grunde vil nogle senescente celler forblive i kroppen og v\u00e6re i vejen for friske celler. <em>Udtr\u00e6tning af stamceller<\/em>: Fornyelsen af mange af kroppens v\u00e6v er baseret p\u00e5 tilstedev\u00e6relse af stamceller. V\u00e6vets funktionelle celler vedligeholdes af en stamcellepool. Hvis stamcelleaktiviteten falder over tid bliver v\u00e6vene ikke l\u00e6ngere vedligeholdt s\u00e5 effektivt som f\u00f8r. <em>\u00c6ndringer i cellul\u00e6r kommunikation<\/em>: Kroppens celler udveksler signaler, b\u00e5de mellem t\u00e6tliggende celler, og over l\u00e6ngere distancer i kroppen, fx ved hormoner. Denne kommunikation er afg\u00f8rende for vedligeholdelse af cellers funktion. \u00c6ndret signalering fra fx senescente celler kan ogs\u00e5 fremme kronisk inflammation i kroppen.<\/p>\n<p>Ovenst\u00e5ende opsummering af de enkelte punkter er en kraftig forenkling af de emneomr\u00e5der, som de omhandler. Man vil ogs\u00e5 kunne finde, at der er overlap mellem mange af punkterne. For eksempel kan cellul\u00e6r senescens i h\u00f8j grad t\u00e6nkes at tilskrives telomer-nedbrydning (l\u00e6s evt. tidligere indl\u00e6g om <a href=\"https:\/\/seniorfitness.blog\/?p=569\">Aldringens biologi<\/a>).<\/p>\n<p>Efterh\u00e5nden som forskellige forskergrupper opn\u00e5r st\u00f8rre viden inden for det omr\u00e5de de fokuserer p\u00e5 falder der nok flere og flere brikker p\u00e5 plads s\u00e5 der kan l\u00e6gges et mere sammenh\u00e6ngende puslespil.<\/p>\n<p>Det \u00e5bne sp\u00f8rgsm\u00e5l er hvad aldringsforskningen vil f\u00f8re til. Bliver det med fokus p\u00e5 sund aldring; at vi f\u00e5r h\u00f8j livskvalitet inden for de eksisterende biologiske rammer for den maksimale levealder for mennesket? Eller bliver fokus p\u00e5 at \u00f8ge vores maksimale levealder ved at manipulere de biologiske systemer ud over gr\u00e6nsen for hvad naturen har dikteret?<\/p>\n","protected":false},"excerpt":{"rendered":"<div class=\"mh-excerpt\"><p>De seneste par \u00e5rtier er det for alvor g\u00e5et op for videnskaben, at det faktum at vi \u00e6ldes ikke kan tilskrives en enkelt \u00e5rsag, men <a class=\"mh-excerpt-more\" href=\"https:\/\/seniorfitness.blog\/?p=3020\" title=\"Kendetegn for cellul\u00e6r aldring\">[&#8230;]<\/a><\/p>\n<\/div>","protected":false},"author":1,"featured_media":3026,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[12],"tags":[97,489,492,323,487,491,488,490,61],"class_list":["post-3020","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-baggrund","tag-aldring","tag-celler","tag-epigenetik","tag-inflammation","tag-mitochondrier","tag-proteostasis","tag-senescens","tag-stamceller","tag-telomerer"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/seniorfitness.blog\/wp-content\/uploads\/2021\/05\/cells-1872666_1280.jpg?fit=1280%2C640&ssl=1","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p8lpEz-MI","jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/seniorfitness.blog\/index.php?rest_route=\/wp\/v2\/posts\/3020","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/seniorfitness.blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/seniorfitness.blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/seniorfitness.blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/seniorfitness.blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3020"}],"version-history":[{"count":3,"href":"https:\/\/seniorfitness.blog\/index.php?rest_route=\/wp\/v2\/posts\/3020\/revisions"}],"predecessor-version":[{"id":3025,"href":"https:\/\/seniorfitness.blog\/index.php?rest_route=\/wp\/v2\/posts\/3020\/revisions\/3025"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/seniorfitness.blog\/index.php?rest_route=\/wp\/v2\/media\/3026"}],"wp:attachment":[{"href":"https:\/\/seniorfitness.blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3020"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/seniorfitness.blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3020"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/seniorfitness.blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3020"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}