Yintoni i-Cell Death? Masithethe ngayo ngokulula!

Ngaba wakha wazibuza ukuba kwenzeka ntoni kwiiseli ezincinci ezingaphakathi emizimbeni yethu? Ngamanye amaxesha, njengathi, ezi seli 'ziyafa' xa ixesha lazo liphelile. Oku sikubiza ngokuba 'kukufa kweeseli' kwezonyango. Nangona oku kuyoyikisa kancinci ukukuva, kubalulekile ngokwenene ukuze imizimba yethu iphile kakuhle kwiimeko ezininzi. Ke namhlanje, masithethe ngokuba oku kufa kweeseli kuyintoni, kwenzeka njani, kwaye kuyichaphazela njani imizimba yethu.

Zithini iiseli? Masiqale siqonde loo nto!

Kulungile, ngaphambi kokuba sithethe 'ngokufa kweeseli', makhe sijonge ukuba zeziphi ezi 'seli' . Khawucinge ukuba umzimba wethu sisakhiwo esikhulu, kwaye iiseli zifana nezitena ezincinci ezenza eso sakhiwo. Enyanisweni, awunakucinga nokuba, kukho iiseli ezingaphezu kwe-30 trillion emzimbeni wethu! Zonke ezi seli ziyadibana ukuze zenze izicubu zethu kunye namalungu ethu. Ngokubanzi, kukho iindawo ezintathu eziphambili zeseli:

• I-membrane yeseli: Oku kufana nocingo olukhuselayo, okanye isango, leseli. Yiyo egqibayo nelawula ukuba yintoni enokungena nephuma kwiseli.
• I-Cytoplasm: Le yinxalenye yolwelo efana nejeli ngaphakathi kwiseli. Ukuveliswa kweeproteni ezifunekayo kwiseli kunye neenkqubo ezininzi ezibalulekileyo zeekhemikhali ezenzeka ngaphakathi kwiseli kwenzeka kule cytoplasm.
• I-Nucleus: Le 'liziko lolawulo' okanye 'ubuchopho' beseli. Ulwazi lwethu lwemfuza, oko kukuthi, i-DNA (`DNA` - i-Deoxyribonucleic acid), lufumaneka kakhulu kule nucleus. I-nucleus ikwadala i-RNA (`RNA` - i-Ribonucleic acid) . Le 'RNA` ikopisha ulwazi olukwi-`DNA` kwaye inceda iiseli zenze iiproteni ezahlukeneyo ezizidingayo ukuze zisebenze kwaye zikhule.

Ngoku unombono ocacileyo wokuba yintoni iseli.

Ngoko ke, yintoni le nto yokufa kweeseli?

Ngamafutshane, ukufa kweeseli kuxa iiseli emzimbeni wethu ziyeka ukusebenza zize zife xa zigqibile umsebenzi wazo okanye zonakele ngesizathu esithile. Iiseli emzimbeni wethu azenziwanga nje kuphela. Zihlala zahlulahlula kwaye zenza iiseli ezintsha. Oku sikubiza ngokuba 'kukwahlukana kweeseli' (`Mitosis`) . Ngokutsho kweengcali, iseli yomntu esempilweni inokwahlukana ngale ndlela malunga namaxesha angama-50-60. Emva koko, iseli iyaguga ize ife.

Imizimba yethu ihlala isenza iiseli ezintsha ukuze zithathe indawo yeeseli ezindala, ezonakeleyo nezifayo. Kufana nokulahla izinto ezindala uze uzise izinto ezintsha.

Oku kufa kweeseli ngokwemvelo kunceda ukugcina imizimba yethu isempilweni kwaye isebenza kakuhle. Nangona kunjalo, iingxaki ziyavela xa oku kufa kweeseli kungenzeki njengoko bekulindelwe, okanye xa iiseli ezingafanele kufa ziqala ukufa.

Kutheni iiseli zethu zisifa? Zithini izizathu?

Kukho izizathu ezahlukeneyo zokuba iiseli zife. Ezinye zezendalo, ezinye azife. Makhe sijonge ezona zizathu ziphambili:

• Ezinye iiseli ziyafa ngelixa zikhula , ngaphambi kokuba zakheke ngokupheleleyo.
• Xa iiseli ezindala zifikelela kwiminyaka apho zingasakwazi ukwahlukana, oko kukuthi, xa ubomi bazo buphelile, ziyafa. Le yinkqubo eqhelekileyo.
• Ukuba kukho iiseli ezonakele ngendlela engenakulungiseka ngandlela ithile, ziyafa ngokwendalo. Azinakugcinwa emzimbeni njengenkunkuma.
• Izifo, ukwenzakala, iityhefu, kunye nonyango oluthile lunokonakalisa iiseli kwaye lubangele ukuba zife.

Ngubani osengozini yokufa kweeseli?

Enyanisweni, ukufa kweeseli kusichaphazela sonke – kwaye kudla ngokuba yinto entle. Kuyamangalisa, ulusu lwakho lukhupha malunga neeseli ezifileyo ezingama-40,000 ngosuku! Umaleko ophezulu wolusu lwethu, obizwa ngokuba yi-epidermis , uhlala uvelisa iiseli ezintsha zolusu ezithatha indawo yezi seli ezifileyo. Ngamanye amazwi, ukuba oku kufa kweeseli bekungenzeki, besingayi kuba nolusu olusempilweni.

Ziziphi iintlobo eziphambili zokufa kweeseli?

Ngokuxhomekeke kwindlela iiseli ezifa ngayo, zinokwahlulwa zibe ziintlobo ezintathu eziphambili:

1. I-Apoptosis - Ukufa kweeseli okucwangcisiweyo

2. I-Autophagy - ukuphinda kusetyenziswe iiseli kunye nokufa kwazo

3. I-Necrosis - Ukufa kweeseli okubangelwa ziingozi

Ngoku masithethe ngeentlobo nganye kwezi ngokweenkcukacha ezithe vetshe.

1. I-Apoptosis okanye ukufa kweeseli okucwangcisiweyo

I-Apoptosis kukufa kweeseli okwenzeka ngokwendalo, okucwangcisiweyo . Kule nkqubo, iiseli ziyazitshabalalisa. Emva kokuba iseli yahlulwe amaxesha amaninzi, xa ifikelela kwinqanaba apho ingasakwazi ukwahlukana, iyafa ngale nkqubo (i-Apoptosis). Oku kufa kweeseli okucwangcisiweyo kusempilweni kakhulu kwaye kulindeleke emizimbeni yethu.

Cinga ngalo mzekelo. Xa iminwe yomntwana iqala ukwakheka esibelekweni sikanina, idityaniswa ngolusu oluncinci phakathi kwayo. Njengesikhumba esiphakathi kweenzwane zemilenze yedada. Kodwa njengoko umntwana ekhula, le nkqubo ye-"Apoptosis" ibangela ukuba iiseli ezingafunekiyo phakathi kwezo minwe zife ngendlela ehlelekileyo. Kulapho iminwe yahlukana kakuhle ize yenze iminwe emihlanu eyahlukileyo. Khawucinge, kuthekani ukuba le "Apoptosis" ayizange yenzeke kakuhle? Emva koko ulusu oluphakathi kwezo minwe lunokuhlala lunjalo. Siyibiza loo meko ngokuthi "Syndactyly" . Uyabona, ngamanye amaxesha kubalulekile ukuba ezi seli zife.

`(Apoptosis)` yinkqubo eyenzeka rhoqo. Yile nto isusa iiseli ezindala, ezonakeleyo emizimbeni yethu, ivulela indlela iiseli eziselula, eziphilileyo ukuba zithathe indawo yazo. Nangona kunjalo, ukuba ngesizathu esithile oku kufa kweeseli okucwangcisiweyo akwenzeki kakuhle, ezo seli zindala, ezonakeleyo ziqala ukwahlukana ngokungalawulekiyo. Le yeyona nto iphambili ekuphuhlisweni kweethumba kunye nomhlaza.

Kwakhona, ngamanye amaxesha ngenxa yeempazamo kwiprogramu yeeseli, iiseli ezingafanelanga zife nazo zinokufa ngale nkqubo ye-"Apoptosis". Umzekelo, kubantu abanezifo ezifana nesifo sikaParkinson, isifo sikaHuntington , okanye isifo sika-Alzheimer, iiseli zemithambo-luvo (" Neurons") kwinkqubo yemithambo-luvo ziyafa kakhulu. Oku kufa kwangaphambi kwexesha kweeseli kunokuchaphazela ukucinga kunye nokuhamba.

2. Ukuphinda usebenzise iiseli okanye ukusetyenzwa kwakhona kwe-autophagy

I-Autophagy lolunye uhlobo lokufa kweeseli okucwangcisiweyo. Kodwa olu lukhethekile. Ludla ngokuvela xa umzimba uphantsi koxinzelelo oluthile, uxinzelelo, okanye ukunqongophala kokutya. Lufana "nenkqubo yokuphinda usebenzise" eyenzeka kwinqanaba leeseli emzimbeni wethu.

Kwinkqubo ethi ``Autophagy``` (oko kuthetha ``ukuzityela ngokwakho''), iseli ``idla'' iiproteni zayo ezindala, ezonakeleyo, okanye ezinye iindawo ezingafunekiyo ze-cytoplasm. Emva koko iphinda isebenzise iindawo eziqhekekileyo kwaye ixhase imisebenzi ebalulekileyo yeseli. Kufana nokulahla izinto ezindala endlwini yakho kwaye uthathe iindawo ezisebenzisekayo kwaye wakhe into entsha.

Le nkqubo ye-"Autophagy" ngamanye amaxesha iluncedo kakhulu.

• Inkqubo yethu yokuzikhusela komzimba inceda ekutshabalaliseni izinto ezifana neentsholongwane kunye neebhaktheriya ezibangela usulelo.
• Inokunceda ekuthinteleni iiseli eziphilileyo ekubeni ziiseli zomhlaza.
• Kukholelwa ukuba oku kunokunceda ekuthinteleni ezinye iingxaki ezifana nesifo sentliziyo .

Kodwa, kwelinye icala, ukuba unomhlaza, le nkqubo ye-"(Autophagy)" inokuba yingozi. Kuba, le nkqubo yokuphinda isetyenziswe inika iiseli zomhlaza izondlo ezongezelelweyo, ezinokukhawulezisa ukukhula kwazo. Akunjalo kuphela, kodwa ezi seli ziphinda zisetyenziswe zinokuphazamisana nokutshatyalaliswa kweeseli zomhlaza ngonyango lomhlaza.

Abanye abantu bazama ukukhuthaza le nkqubo ye-"Autophagy" ngokunciphisa iikhalori okanye ukuzila ukutya, ngaloo ndlela bevelisa iiseli eziselula nezisempilweni. Nangona kunjalo, akukho bungqina besayensi obaneleyo bokuba ukwenza i-"Autophagy" ngokwenziwa ngokungekho mthethweni ngale ndlela kuyasebenza. Kwakhona, imiqathango engqongqo yokutya ngamanye amaxesha inokuba yingozi empilweni.

3. I-Necrosis okanye ukufa kweeseli ngequbuliso

I-Necrosis ayilonkqubo ecwangcisiweyo njenge-Apoptosis okanye i-Autophagy. Kukufa kweeseli ngengozi okanye okungalindelekanga. Oku kuphumela ekufeni kwezicubu.Kwenzeka. Khawuthelekelele ukuba wenzakele kakhulu engalweni okanye emlenzeni wakho. Ngelo xesha, iiseli ezonakeleyo zonakele, kwaye umxholo wazo uyavuza, nto leyo enokonakalisa iiseli eziphilileyo ezizingqongileyo. Oku kubangela ukudumba, ukubomvu, iintlungu, kunye nokunye ukulimala nokufa kwezinye iiseli.

Into ebalulekileyo kukuba, nangona oogqirha benokususa esi sicwili sifileyo, ukufa kwesicwili okubangelwa yi-"necrosis" akunakuguqulwa.

Le meko, ethi "Necrosis," inokwenzeka ngenxa yokuncipha kokunikezelwa kwegazi kunye nokunikezelwa kweoksijini kwiindawo ezithile zomzimba. "Necrosis" yenzeka kuba iiseli azifumani igazi, ioksijini, kunye nezondlo xa sisifa.

Ezinye izizathu ze-`(Necrosis)` zezi:

• Iingozi kunye nokwenzakala okunzulu (`Ukwenzakala okubuhlungu`).
• Izifo ezizikhusela ngokwazo emzimbeni .
• Iibhaktheriya, iintsholongwane, kunye neefungi ezibangela usulelo.
• Ukusetyenziswa kweetyhefu, izinto ezinobungozi kunye neziyobisi ezingekho mthethweni.
• Unyango lomhlaza olufana nonyango lwemitha .

Iintlobo zeNecrosis

Kukho iintlobo ezahlukeneyo ze-`(Necrosis)` ngokuxhomekeke kwisizathu kunye nenxalenye yomzimba echaphazelekileyo. Ezinye zezona ntlobo zixhaphakileyo zezi:

• I-Avascular necrosis okanye i-osteonecrosis (ukufa kwezicubu zethambo)
• I-Gangrene ( ukufa kwezicubu zolusu)
• I-Pulp necrosis ( ukufa kwe-pulp yezinyo)

Yintoni i-Activation-Induced Cell Death (AICD)?

Le yingongoma enzima, kodwa kulungile ukuyazi ngokulula. Ukufa kweeseli okubangelwa kukusebenza (AICD) yingxaki enokubakho yophuhliso lonyango lomhlaza olubizwa ngokuba yi-chimeric antigen receptor (CAR) T-cell therapy . Kwenzeka xa ii-T-cells, uhlobo lweseli emhlophe yegazi enceda ukubulala iiseli zomhlaza, zisifa ngaphambi kwexesha.

Kwi-`(CAR) T-cell therapy`, oogqirha benza into efana nale:

1. I-Leukapheresis yinkqubo esusa iiseli ezimhlophe zegazi ezinyuswe ngokugqithisileyo (kuquka iiseli ze-T) egazini lesigulana.

2. Emva koko ezi T-cells ziyavuselelwa kwilebhu kwaye zizame ukuzikhulisa ngakumbi.

3. Ulwazi olutsha lwemfuza longezwa kwezi T-cells zikhuliswe elebhu, zitshintsha ukuze zikwazi ukukhangela nokutshabalalisa iiseli zomhlaza.

4. Ekugqibeleni, ii-T-cells eziguquliweyo zibuyiselwa egazini lomguli. Emva koko zikhangela kwaye zitshabalalise iiseli zomhlaza.

Kodwa, ngelishwa, xa ezi T-cells zisebenza kwaye zikhulela elabhoratri, ngamanye amaxesha oku kufa kweeseli "ze-AICD" kunokwenzeka. Emva koko, inani leeT-cells eziguquliweyo ezikhoyo zokulwa nomhlaza liyancipha.

Oko kufuneka sikukhumbule kuko konke oku (Umyalezo Wokuya Ekhaya)

Nangona igama elithi 'ukufa kweeseli' lisenokuvakala lisoyikisa kancinci, ngoku uyazi ukuba le yinkqubo eyenzeka ngokwendalo emizimbeni yethu uninzi lwexesha kwaye ibalulekile ukuze siphile kakuhle .

• Ukufa kweeseli okucwangcisiweyo okubizwa ngokuba yi-apoptosis kususa iiseli ezindala, ezonakeleyo kwaye kwenze indlela yeeseli eziselula nezisempilweni.
• Ngenkqubo ebizwa ngokuba yi-autophagy , iiseli ziyaphinda zisebenzise iindawo zazo kwaye zisebenze kakuhle ngakumbi.
• Nangona kunjalo, ukufa kweeseli ngenxa yeengozi ezifana ne -necrosis kuyingozi kwaye kunokubangela umonakalo ongapheliyo kwizicubu.
• Kwakhona, ngamanye amaxesha `(Apoptosis)` kunye `(Autophagy)` zinokuba negalelo kwizifo ezifana nomhlaza.

Nangona kunjalo, imizimba yethu ihlala ixakekile ilungisa iiseli ezonakeleyo kwaye itshintsha ezo zifayo. Kungoko ke, kubalulekile ukuba uqaphele le nkqubo. Ukuba unemibuzo okanye iinkxalabo malunga noku, ungathandabuzi ukuthetha nogqirha.

Ukufa kweeseli , iiseli, i-apoptosis, i-autophagy, i-necrosis, umsebenzi womzimba, ukwahlukana kweeseli