Abanye abaphandi bakholelwa ukuba i-amyloid iyaphazamisa i-hypothesis ngokucacileyo imbangela yesifo se-Alzheimer .
Nangona imibuzo emininzi ingaphenduliwe, i-amyloid ihlasela i-hypothesis iphakamisa ukuba ukuqokelela ngokweqile kwe-peptide ebizwa ngokuthi i- amyloid-beta yinto ephambili kwisifo se-Alzheimer: Olu qoqo lubeka uchungechunge lweziganeko ezibangelwa ukufa kweeseli zobuchopho, ekugqibeleni, Isifo se-Alzheimer.
Indlela i-Amyloid-Beta ingayenza ngayo i-Alzheimer's
I-Amyloid-beta ivela kwiprotheyini enkulu ebizwa ngokuba yiprotropropylene protein (APP). Abaphandi abazi kakuhle umsebenzi we-APP okwamanje, kodwa kunokuchaphazela umsebenzi weeseli zobuchopho. Ii-enzyme ezikhethekileyo (ezibizwa ngokuba yi-secretase) zinqumle le protheni kwiindawo ezithile, kwaye enye yeemveliso zale "coavage" yi-amyloid-beta peptide. Ezi peptide ze-amyloid-beta zihlangene kunye nento ebizwa ngokuba yi-oligomers, kwaye ngokutsho kwe-amyloid i-hypothesis, i-oligomers inetyhefu kwiiseli zengqondo, ezibangela iingxaki zokuqala ezinengqondo kwi-Alzheimer's disease. Kamva, la ma-oligomers enza iiplati ezibonakalisa isifo se-Alzheimer, kodwa yi-oligomers-ngokuchasene neeplates - ezizona zixhepha eziyingozi.
Nangona iindidi zobungqina obuxhasa ukuba i-amyloid ihlasele i-hypothesis, kukho imingeni eninzi kuyo.
Enye into, i-amyloid-beta eqokelela kwi-plaque ivela ekuguga ngokuqhelekileyo kunye nesifo se-Alzheimer. Kwesinye, iipositi zezinye iiprotheyini ezibizwa ngokuba yi-tau ifom tangles ezihambelana kakuhle kunye neengxaki zengqondo kwi-Alzheimer's disease kunezicatshulwa. Ekugqibeleni, kukho ezinye iingcamango ezingezinye, ezifana ne-mitochondrial cascade hypothesis, eziye zacetyiswa njengeenkcazo zezinto ezibangela isifo se-Alzheimer.
Umthombo:
Christensen DD. Isifo se-Alzheimer: inkqubela phambili ekuphuhliseni izifo ezichasene ne-amyloid- ukuguqulwa kwezifo. CNS Spectr. 2007; 12: 113-123.
-Iqendu Ehleliwe nguEstere Heerema, MSW