Nkhani
Methylene blue monga choletsa ndi cholimbikitsa okosideshoni: n’chiyani chimasintha zotsatira?
Tiyerekeze kuti malo awiri ofufuza ayesa utoto wabuluu womwewo koma anena zotsatira zotsutsana. Kumalo oyamba, mitokondriya yochotsedwa m'maselo a ubongo imagwiritsa ntchito mpweya bwino ndipo imapanga ATP yambiri. Kumalo achiwiri, mitokondriya yokonzedwa mofanana imatulutsa hydrogen peroxide yochuluka kwambiri. Malipoti onse awiri ndi olondola. Amafotokoza kuzungulira komweko koma kuchokera mbali ziwiri, ndipo chisokonezo chimayamba pamene owerenga amaona mbali imodzi ngati nkhani yonse.
Cholakwika n’kufunsa kuti molekyuluyi ili m’gulu liti. Methylene blue imakhala ngati wopatsirana maelekitironi, monga mapu a malo amene imakhudza m’maselo akusonyezera mwatsatanetsatane. Utoto womwe wachita okosideshoni umalandira maelekitironi ndipo umasanduka leucoMB yopanda mtundu. LeucoMB imapereka maelekitironiwo kwina ndipo imakhalanso yabuluu. Zimene mumaona zimadalira amene akupereka maelekitironi, amene akuwalandira, ndi ngati dongosololo lingathe kuchotsa hydrogen peroxide yomwe imapangidwa m’njiramo. Funso lofunika si lakuti utotowo umaletsa okosideshoni kapena ayi. Ndi lakuti mikhalidwe yomwe ilipo imalola kupatsirana maelekitironiko kuchita chiyani.
Kuzungulira kumene kumabweretsa mbali zonse ziwiri
Mumdima, kuzungulira kwakukulu kumakhala kwachidule. NADH, NADPH, kapena zinthu zonyamula maelekitironi m’unyolo wopangira mphamvu zimapereka maelekitironi ku utotowo. Utoto wolandira maelekitironi umakhala ndi njira zosiyanasiyana zoperekera maelekitironiwo. Ungawapereke ku cytochrome c ndi kuthandiza kuti kuyenda kwa maelekitironi kudutse pambali pa gulu lowonongeka la mapuloteni. N’chifukwa chake kugwiritsa ntchito mpweya ndi kusiyana kwa mphamvu yamagetsi pa nembanemba zimabwezeretsedwa pang’ono pamene complex I kapena III yatsekedwa. Kapenanso ungapereke maelekitironi molunjika ku oxygen, zomwe zimabwezeretsa mtundu wabuluu ndi kupanga hydrogen peroxide. Popeza utotowo umabwezeretsedwa, kuchuluka kochepa kungabwereze kuzungulira kumeneku nthawi zambiri, kukugwiritsa ntchito zinthu zoperekera maelekitironi ndi kupanga peroxide mosalekeza.
Nthambi zina ziwiri zimasinthiratu mmene zinthu zimachitirana. Mkuwa kapena chitsulo chosamangiriridwa chimasintha peroxide yomwe imatha kufalikira kukhala zinthu zoyambitsa okosideshoni zowononga kwambiri pafupi pomwepo, kudzera m’zochitika za mtundu wa Fenton. Kuwala kofiira kumatsegula nthambi ina ya zochitika zoyambitsidwa ndi kuwala. Mmenemo, utoto womwe wapatsidwa mphamvu ndi kuwala umasamutsira mphamvuzo ku oxygen ndi kupanga singlet oxygen, mtundu wa oxygen wofotokozedwa mwatsatanetsatane mu kufotokoza zochitika zoyambitsidwa ndi kuwala za mtundu I ndi mtundu II. Kuzungulira kwa kupereka ndi kulandira maelekitironi mumdima, kuwonongeka kolimbikitsidwa ndi zitsulo, ndi kuwonongeka koyambitsidwa ndi kuwala ndi njira zitatu zosiyana zomwe zimangoyambira pa molekyulu imodzimodzi.
Tebulo la mikhalidwe ndi zotsatira
Tebulo ili m’munsimu ndi lofunika kusunga. Mzere uliwonse ukusonyeza chinthu chimodzi chosinthika, mbali imene chimakankhira zotsatira, ndi kuyesa komwe kukuchirikiza zimenezo. Zabwino zikutanthauza muyeso wosonyeza chitetezo kapena kusintha kwabwino. Zoipa zikutanthauza kuwonjezeka kwa zinthu zoyambitsa okosideshoni, kutha kwa zinthu zoteteza, kapena kuwonongeka.
| Mkhalidwe | Mbali ya zotsatira | Zimene kuyesako kunasonyeza |
|---|---|---|
| Kuchuluka kochepa, 0.1 mpaka 1 uM, mitokondriya yochotsedwa m’maselo | Kupanga mphamvu kwabwino komanso peroxide yochuluka | 0.1 uM inapititsa patsogolo kugwiritsa ntchito oxygen m’mitokondriya ya mtima wa makoswe athanzi ndi odwala shuga; 100 nM mpaka 1 uM inabwezeretsa pang’ono ATP, kusiyana kwa mphamvu yamagetsi pa nembanemba, ndi kulowetsa calcium m’mitokondriya ya ubongo yotsekedwa, pamene kutulutsidwa kwa peroxide kunakwera m’mikhalidwe yonse |
| Kuchuluka kwakukulu, koposa 5 uM, maselo opanda glucose | Muyezo woipa wa zinthu zoyambitsa okosideshoni | Maselo a m’kati mwa mitsempha anachititsa okosideshoni pa choyezera ROS chosankha mitundu yambiri ndipo glutathione yawo yolandira maelekitironi inachepa pamene kuchuluka kunaposa 5 uM popanda glucose; kuwonjezera glucose kunaletsa zonsezi |
| Zinthu zoperekera maelekitironi ku complex I (glutamate ndi malate) | Peroxide yochuluka | Kafukufuku wa mitokondriya ya ubongo ndi wa mtima onse anapeza kuti kutulutsidwa kwa peroxide kunakwera pogwiritsa ntchito zinthu zolumikizidwa ndi NADH |
| Succinate ndi rotenone, mitokondriya ya mtima, 0.1 uM | Peroxide yochepa potsatira njira yoyesera imeneyo | Uwu ndi muyeso umodzi wokha wa peroxide m’gululi womwe unasonyeza bwino kuletsa okosideshoni; dziwani kuti njira yoyeserayo inaphatikiza rotenone ndi minofu ina, choncho chinthu choperekera maelekitironi chokha sichikufotokoza zotsatirazo |
| Kuwala kofiira, 20 uM ndi 630 nm | Kuwonongeka koipa kwa DNA | Panalibe kuwonongeka kwakukulu kwa DNA ya mitokondriya mumdima pa 20 uM; kuchuluka komweko pamodzi ndi kuwala kofiira kunawononga chidutswa chilichonse choyesedwa |
| Kuchuluka kwakukulu kwambiri mumdima, 100 uM | Kuwonongeka koipa kwa DNA kosankha malo ena | DNA ya mitokondriya inawonongeka makamaka pamagawo okhala ndi purine yambiri, kusintha kwakukulu poyerekeza ndi muyeso wa peroxide pa kuchuluka kwa nanomolar |
| Mkuwa kapena chitsulo ndi NADH, DNA yopanda maselo | Kuwonongeka koipa chifukwa cha okosideshoni | Mkuwa unalunjika kuwonongeka pagawo la p53 lomwe limawonongeka pafupipafupi; iron EDTA inawononga malo ambiri; catalase ndi zinthu zomanga ayoni a zitsulo zinaletsa njira zake motsatana; guanine yomwe inachita okosideshoni inawonjezeka |
| Glucose ilipo, maselo athunthu | Kuteteza ku kupsinjika ngakhale kuzungulira kukufulumira | Glucose inawonjezera kulandira maelekitironi kwa utoto koma inachepetsa kupsinjika konse, mogwirizana ndi kupangidwa kwa NADPH kudzera m’njira ya pentose phosphate kuti zinthu zoletsa okosideshoni zigwiritsidwenso ntchito |
| Maselo okhala ndi ascorbate yochuluka | Zosakanikirana: ascorbate inagwiritsidwa ntchito, muyeso wa choyezera unachepetsedwa | Utoto unapitiriza kuchititsa okosideshoni ya ascorbate m’maselo ngakhale glucose ilipo, koma unachepetsanso pang’ono okosideshoni ya choyezera; zinthu zosungidwa zoteteza maselo ndizo zinagwiritsidwa ntchito |
| Nyama zokonzedwa ndi rotenone, utoto waperekedwa poyamba | Zotsatira zabwino m’minofu | Kupereka utoto poyamba kunachepetsa kuwonongeka kwa DNA ya mitokondriya koyambitsidwa ndi rotenone m’chigawo chapakati cha ubongo wa mbewa, ngakhale utotowo unawonjezera peroxide m’mitokondriya yochotsedwa m’maselo |
Chofunika ndi mmene mizere yonseyi ikugwirizanira. Kupanga peroxide ndi kuteteza zinthu zamoyo ndi mbali ziwiri zosiyana. Chinthu chimene chayikidwa poyesa chingasonyeze zotsatira zoipa pa mbali yoyamba ndi zabwino pa yachiwiri nthawi imodzi.
Chifukwa chake kuchuluka komweko kumapereka mayankho osiyana
Kuchuluka kwa utoto kumakhazikitsa mphamvu yake yonyamula maelekitironi, osati zotsatira zake zomaliza. Kutulutsidwa kwa peroxide kuchokera m’mitokondriya ya ubongo kunakwera mokwanira kuti kuonekere kuyambira pa 50 nM kupita m’mwamba mu kafukufuku wa mitokondriya ya ubongo yosasweka, pamene kuwonongeka koonekeratu kwa DNA ya mitokondriya kunafuna 100 uM mumdima. Kusiyana pakati pa muyeso woyamba ndi kuwonongeka kwa DNA ndi pafupifupi kuwirikiza zikwi ziwiri, koma si malire otsimikizira chitetezo. Zotsatira zoyezedwa, zigawo zoyesedwa, ndi nthawi yokhudzidwa ndi utoto zimasiyana, choncho manambalawa akuimira zochitika zosiyana osati mfundo pa mzere umodzi wa zotsatira. Kukambirana za mmene zotsatira zimasinthira malinga ndi kuchuluka kumayika kusiyana kotereku pakati pa muyeso wochepa ndi kuwonongeka kwakukulu m’lingaliro lonse la hormesis.
Zinthu zoperekera maelekitironi zimasankha kumene maelekitironi amalowera. Zinthu zopangira mphamvu zolumikizidwa ndi NADH zimapatsa utoto maelekitironi ochuluka oti ugwiritse ntchito ponse pawiri: njira yothandiza yodutsa pambali pa malo otsekedwa ndi zochitika zosakaza maelekitironi powapereka ku oxygen. Mawu amene amabwerezedwa kawirikawiri akuti succinate imapangitsa utoto kuletsa okosideshoni pamene glutamate imaupangitsa kulimbikitsa okosideshoni amatanthauzira deta mopitirira zimene ikusonyeza. Izi zili choncho chifukwa mkhalidwe woyezera peroxide ndi succinate m’kafukufuku wa mtima unalinso ndi rotenone ndipo unagwiritsa ntchito minofu ndi kuchuluka kosiyana ndi kafukufuku wa ubongo amene anapeza peroxide yokwera ndi chinthu chilichonse choperekera maelekitironi komanso mkhalidwe uliwonse wa kugwiritsa ntchito mpweya.
Kuwala kumasintha njira imene zinthu zimachitikira, osati kungosintha kukula kwa zotsatira. Kusiyana koonekeratu kwambiri m’gululi ndi kwakuti 20 uM mumdima sinachite chilichonse chooneka pa zidutswa za DNA ya mitokondriya, pamene 20 uM pansi pa kuwala kofiira inawononga zonsezo. Aliyense amene akuyerekezera kuyesa kokhala ndi kuwala ndi kopanda kuwala akuyerekezera zochitika zoyambitsidwa ndi kuwala ndi kuzungulira kwa kupereka ndi kulandira maelekitironi.
Zitsulo zimasintha chinthu choyambitsa okosideshoni. Popanda zitsulo, kuzungulira kwa utoto mumdima kumapanga peroxide, molekyulu yomwe imatha kufalikira ndipo maselo amaigwiritsanso ntchito potumiza zizindikiro. Pakakhala mkuwa kapena chitsulo chomwe chingatenge nawo mbali, utoto wolandira maelekitironi kuchokera ku NADH umapereka maelekitironiwo ku zitsulo. Zitsulozo zikalandira maelekitironi, zimayambitsa peroxide kupanga zinthu za mtundu wa hydroxyl kapena copper peroxide pafupi ndi DNA. Umu ndi mmene kafukufuku wopanda maselo wokhala ndi NADH ndi ayoni a zitsulo unapangira kuwonongeka kwa DNA kolunjika kumalo amene amawonongeka pafupipafupi komanso kuwonongeka kwa malo ambiri, pogwiritsa ntchito utoto woyambira womwewo. Mmene chigawocho chimasamalirira zitsulo, osati utoto wokha, ndiko kumatsimikiza ngati nthambi imeneyi ili ndi zotsatira zofunika.
Kupezeka kwa zinthu zopangira mphamvu kumatsimikiza ngati selo lingakwanitse kulipira mtengo wake. Mu maselo a m’kati mwa mitsempha omwe anakhudzidwa ndi utoto wa 2 mpaka 20 uM, kuchotsa glucose kunaonetsa mtengo wa okosideshoni pamene kupereka glucose kunauthetsa, ngakhale glucose inafulumizitsanso kulandira maelekitironi kwa utoto. Kuzungulira kofulumira pamene zinthu zoteteza zilipo n’kwabwino kuposa kuzungulira kochedwa pamene zinthu zoteteza zatha. Tengani mawu alionse onena za zinthu zoyambitsa okosideshoni omwe sakutchula kupezeka kwa glucose kapena NADPH ngati osakwanira.
Mtundu wa minofu ndi umene umasankha zida zomwe zilipo. Maselo a m’kati mwa mitsempha amapanga NADPH yatsopano kudzera pakugwiritsa ntchito glucose ndipo ali ndi zinthu zosungidwa zoletsa okosideshoni m’madzi a m’kati mwa selo. Mitokondriya yochotsedwa m’maselo ilibe zimenezo. DNA yoyeretsedwa ilibe ngakhale njira zodzikonzera. Zotsatira zochokera m’chinthu chimodzi chokonzedwa poyesa sizimaneneratu zambiri za zina. N’chifukwa chake nkhani yokonzedwa yofotokoza mayankho a mitundu yosiyanasiyana ya minofu idzafunika kusiyanitsa machitidwe amenewa.
Kuyeza mwachindunji si kuyeza chitetezo chimene chimabwera pambuyo pake
Zolemba zambiri zimaphatikiza magawo awiri amene mayeserowo amawasiyanitsa. Gawo limodzi limafunsa kuti zinthu zoyambitsa okosideshoni zinaoneka zochuluka bwanji. Lina limafunsa kuti selo linayankha bwanji.
Mayeso a peroxide a mtundu wa Amplex ndiwo ali pafupi kwambiri ndi gawo loyamba. Komabe, nawonso amasonyeza kusintha konse komaliza, kutanthauza kupanga kuchotsa zomwe zawonongedwa kuchotsanso zomwe zatulutsidwa. Kafukufuku wa mitokondriya ya ubongo anapeza kuti mbali zonse ziwiri zinasintha: peroxide yambiri inapangidwa ndipo kuchotsedwa kwa peroxide yowonjezedwa nthawi imodzi kunachedwa. Zochitika zotsatira zimaphatikizapo okosideshoni ya glutathione, kugwiritsidwa ntchito kwa ascorbate, guanine yomwe yachita okosideshoni, ndi kuwonongeka kwa DNA komwe kumalepheretsa polymerase. Sitepe iliyonse imawonjezera zochitika zamoyo pakati pa chinthu choyambitsa okosideshoni ndi muyeso wake.
Maenzayimu oletsa okosideshoni oyendetsedwa ndi Nrf2 ndi kupanga mitokondriya yatsopano zili m’gawo lachiwiri. Ndi njira zosinthira kuti maselo azolowere mikhalidwe, zomwe peroxide yochepa ya nthawi yochepa ingayambitse. Olemba kafukufuku wa kutetezedwa kwa mitokondriya ya ubongo akupereka lingaliro lakuti kupsinjika kochepa kumeneku ndiko koyambitsa, koma akunenanso kuti kufotokoza unyolo wa zomwe zimayambitsana kudzera mu Nrf2 kumadalira kafukufuku wakale osati umboni wawo wathunthu. Chitetezo chimene chimafika patapita maola kudzera m’mapuloteni atsopano sichikutanthauza kuti zochitika zoyambirira zinali zoletsa okosideshoni. Zikutanthauza kuti chochitika chaching’ono cholimbikitsa okosideshoni chinabweretsa chitetezo chachikulu. Malangizo owerengera mawu oterewa mosamala, kuphatikizapo malire a mayeso ndi kusiyana kwa zinthu zokonzedwa poyesa, ndiwo nkhani ya buku lotsogolera powerenga kafukufuku wa methylene blue.
Chifukwa chake mayeso samagwirizana
Choyezera chosankha mitundu yambiri monga dihydrofluorescein chimasonyeza okosideshoni ya choyezera yokhudzana ndi zinthu zosiyanasiyana, osati kuchuluka kwa peroxide. Chimadalira zochitika za peroxidase ndi heme ndipo chingaphonye kukwera kwa peroxide komwe mayeso a Amplex olinganizidwa moyenera angazindikire. Kafukufuku wa mitokondriya ya ubongo anaona peroxide yokwera kwambiri popanda muyeso wa superoxide wokwera mofanana. Izi ndi chenjezo losadalira mawu alionse onena za kuletsa okosideshoni ochokera pa choyezera chimodzi chokha chogwiritsa ntchito utoto. Kulowererana kwa kuyamwa ndi kutulutsa kuwala ndi funso loyenera kufufuzidwa, chifukwa utotowo umayamwa kuwala kooneka pafupi ndi madera amene zida zambiri zimagwiritsa ntchito poyambitsa ndi kuyeza kuwala. Koma kafukufuku wochitidwa mosamala uja unalinganiza mayesowo ndi peroxide ya kuchuluka kodziwika, unachepetsa nthawi ya kuwala koyambitsa popanda kusintha kwambiri muyeso, ndipo unatsimikizira kuchedwa kwa kuchotsedwa kwa peroxide ndi elekitirodi ina. Kusokoneza muyeso ndi chinthu choyenera kuyesa, osati chifukwa chongokana zotsatira.
Zotsatira za calcium zikusonyeza kufunika komweko kwa kulondola. Kugwiritsa ntchito utoto kwa nthawi yochepa sikunasinthe kuchuluka konse kwa calcium nembanemba isanasinthe kulola zinthu kudutsa m’kafukufuku wa mtima. Komabe, kunapititsa patsogolo liwiro la kulowetsa calcium m’mitokondriya ya ubongo yotsekedwa, monga zanenedwa mu kafukufuku wa mitokondriya ya mtima womwe unayang’ana kwambiri matenda a shuga. Zotsatira zoyezedwa zinali zosiyana, machitidwe anali osiyana, ndipo palibe kutsutsana.
Mndandanda wofufuza musanakhulupirire chigamulo
Tengani chigamulo chilichonse chakuti chinthu chimaletsa kapena chimalimbikitsa okosideshoni ngati lipoti la dongosolo linalake, ndipo funsani mafunso asanu. Chinali pa kuchuluka kotani, ndipo m’chigawo chiti? Ndi chiyani chinapereka maelekitironi, ndipo ndi zinthu ziti zomwe zinkapikisana powalandira? Panali kuwala kapena mdima, ndipo kuwalako kunali ndi kutalika kwa funde ndi kuchuluka kotani? Ndi zitsulo ziti zomwe zinalipo, ndipo zinthu zopangira mphamvu ndi zinthu zosungidwa zoletsa okosideshoni zinali zokwanira bwanji? Ndipo anagwiritsa ntchito mayeso ati, oyeza kuyenda kwa zinthu zoyambitsa okosideshoni, kuwonongeka, kapena mayankho osinthira kuti maselo azolowere? Sinthani yankho lililonse limodzi, ndipo molekyulu yomweyo ingachoke pa mbali yoteteza n’kupita pa yowononga m’tebulolo popanda kutsutsana kulikonse.