I-Cerebrosides wuhlobo lwe-lipid olutholakala ngokuyinhloko kulwelwesi lwamangqamuzana ezinzwa, ikakhulukazi ebuchosheni. Akhiwa iqembu lama-molecule aziwa ngokuthi ama-glycosphingolipids, aqukethe i-fatty acid exhunywe ku-sphingosine noshukela. Ama-cerebrosides adlala indima ebalulekile ekuxhumaneni phakathi kwamangqamuzana ezinzwa, ukwakheka kwe-myelin sheath, kanye nokulawulwa kokusebenza kobuchopho. Baphinde bahileleke ezinqubweni ezifana nenkumbulo, ukufunda, kanye nepulasitiki yobuchopho. Ngamafuphi, ama-cerebrosides abalulekile ekusebenzeni kahle kwesimiso sezinzwa nempilo yobuchopho.
Abaluleke kangakanani ama-Cerebrosides ekusebenzeni kobuchopho bomuntu?
Ama-Cerebrosides ama-lipids ayinkimbinkimbi atholakala ebuchosheni bomuntu adlala indima ebalulekile ekusebenzeni kahle kwesimiso sezinzwa esimaphakathi. Akhona kumaseli wezinzwa futhi enza imisebenzi eminingana ebalulekile empilweni yobuchopho.
Enye yezindima eziyinhloko ze-cerebrosides ukusebenza njengezingxenye zesakhiwo samangqamuzana obuchopho. Basiza ukugcina ubuqotho be-membrane kanye ne-fluidity, ukuqinisekisa ukuxhumana okuphumelelayo phakathi kwamangqamuzana ezinzwa. Ngaphezu kwalokho, ama-cerebrosides nawo abandakanyeka ekwakhekeni kwama-myelin sheaths, abalulekile ekudluliselweni okusheshayo kwemizwa yezinzwa.
Omunye umsebenzi obalulekile we-cerebrosides ulawula umsebenzi wama-enzyme nama-neurotransmitter receptors ebuchosheni. Basiza ukulungisa ukukhululwa kanye nokuthathwa kwama-neurotransmitters, njenge-dopamine ne-serotonin, ebalulekile emisebenzini ehlukahlukene yobuchopho, okuhlanganisa isimo sengqondo, inkumbulo, nokufunda.
Ngaphezu kwalokho, ama-cerebrosides nawo adlala indima ebalulekile ekuvikeleni ubuchopho emonakalweni we-oxidative nokuvuvukala. Zinezindawo ezilwa nokuvuvukala kanye ne-antioxidant ezisiza ukuvimbela ukucindezeleka kwe-oxidative nokuvuvukala ebuchosheni, ukuvikela amangqamuzana ezinzwa emonakalweni nokufa kwamangqamuzana.
Kafushane, ama-cerebrosides abalulekile ekusebenzeni kobuchopho okunempilo, adlala indima ebalulekile ekwakhiweni kolwelwesi lwamangqamuzana, ukudluliselwa kwemizwa yezinzwa, ukulawulwa kwama-neurotransmitters, nokuvikelwa emonakalweni we-oxidative nokuvuvukala. Ukugcina amazinga anele e-cerebrosides ebuchosheni kubalulekile ebuchosheni obunempilo kanye nokusebenza kahle kwengqondo.
Izindima eziyinhloko ezidlalwa ama-Sphingolipids emzimbeni womuntu.
I-Sphingolipids iyisigaba se-lipids esibalulekile ekusebenzeni kahle komzimba womuntu. Badlala izindima ezimbalwa ezibalulekile, okubandakanya ukwakheka kwamangqamuzana eseli, ukusayina kwamaseli, kanye nokulawulwa kwe-metabolic. Enye yezindima eziyinhloko ze-sphingolipids ukusebenza njengezingxenye zesakhiwo se-membrane yeseli, iqinisekisa ubuqotho bayo kanye noketshezi.
Ngaphezu kwalokho, ama-sphingolipids abandakanyeka ekusayineni kwamaseli, ukudlulisa ulwazi phakathi kwamaseli kanye nezinqubo zokulawula ezifana nokukhula, ukuhlukaniswa, nokufa kweseli. Baphinde badlale indima ebalulekile ekulawuleni i-metabolism, okuhlanganisa ukumuncwa kwezakhi kanye nokukhiqizwa kwamandla.
I-Cerebrosides wuhlobo oluthile lwe-sphingolipid oludlala indima ebalulekile ohlelweni lwezinzwa. Aqukethe i-sphingosine exhunywe ku-fatty acid kanye neqembu le-carbohydrate. Ama-cerebrosides atholakala ngokuyinhloko kulwelwesi lwamangqamuzana ezinzwa futhi adlala indima ebalulekile ekudlulisweni kwezimpawu zezinzwa.
Lawa ma-lipids abalulekile ekwakhiweni nasekugcinweni kwe-myelin sheath, isakhiwo esizungeza ama-axon amangqamuzana ezinzwa futhi sibalulekile ekudluliselweni okuphumelelayo kwemizwa yezinzwa. Ngaphezu kwalokho, ama-cerebrosides abandakanyeka ekulawuleni ipulasitiki ye-neuronal nokuvikela amangqamuzana ezinzwa emonakalweni we-oxidative nokuvuvukala.
Kafushane, ama-sphingolipids, okuhlanganisa ama-cerebrosides, adlala indima ebalulekile emzimbeni womuntu, ebaluleke kakhulu ekwakhiweni kwamangqamuzana nokusebenza kwawo, ukusayina kwamangqamuzana kanye nokulawulwa kwe-metabolism, ikakhulukazi ohlelweni lwezinzwa.
Ukuhlukaniswa kwama-Sphingolipids: qonda ukuthi lawa ma-lipids abalulekile weselula ahlukaniswa kanjani.
Ama-sphingolipids ayikilasi lama-lipids eselula abalulekile emisebenzini ehlukahlukene yezinto eziphilayo. Bahlukaniswa ngokuya ngesakhiwo se-sphingosine yabo kanye nemvelo yezinsalela zabo ze-carbohydrate. Kunezigaba ezine eziyinhloko ze-sphingolipids: i-ceramide, i-sphingomyelins, i-gangliosides, ne-cerebrosides.
I-Cerebrosides, eyaziwa nangokuthi i-neutral glycolipids, yenziwe nge-molecule ye-sphingosine exhunywe ku-fatty acid nge-amide bond. Ziqukethe insalela eyodwa ye-carbohydrate exhunywe ku-molecule ye-sphingosine. Lawa ma-lipids atholakala ngokuyinhloko emgodleni we-myelin, ungqimba oluvikelayo oluzungeza ama-neurons, oluhlinzeka ngokuvikeleka kanye nokwenza lula ukudluliswa kwemizwa yezinzwa.
Ngaphezu komsebenzi wabo wesakhiwo ku-myelin sheath, ama-cerebrosides nawo ahilelekile ekuboniseni amaseli kanye nezinqubo zokuqashelwa kwamaseli. Adlala indima ebalulekile ekukhulumisaneni phakathi kwamangqamuzana ezinzwa nasekulawuleni ukuthuthukiswa nokusebenza kwesimiso sezinzwa.
Kafushane, ama-cerebrosides ayikilasi lama-sphingolipids abalulekile ekusebenzeni kahle kwesimiso sezinzwa, asebenza kokubili esakhiweni se-myelin sheath kanye nokusayina kweseli. Isakhiwo sawo esilula kodwa esibalulekile siwenza ama-molecule ayisisekelo empilweni nasekusebenzeni kobuchopho nohlelo lwezinzwa lulonke.
Qonda umqondo wePlasmalogen nokubaluleka kwayo emzimbeni womuntu.
I-Plasmalogens wuhlobo lwe-lipid olutholakala kulwelwesi lwamaseli, ikakhulukazi amangqamuzana ezinzwa. Aqukethe i-fatty acid exhunywe ku-alcohol ochungechunge olude ngebhondi ye-ether. Lesi sakhiwo esiyingqayizivele sinikeza ama-plasmalogens izakhiwo ezikhethekile, njengokukhuphuka kwe-fluidity kanye nokumelana ne-oxidation.
Lawa ma-lipids adlala indima ebalulekile ekusebenzeni kobuchopho, asebenza njengezingxenye zesakhiwo solwelwesi lwe-neuronal futhi anikele ekuxhumaneni phakathi kwamangqamuzana ezinzwa. Ngaphezu kwalokho, ama-plasmalogens abandakanyeka ekulawuleni i-lipid metabolism futhi avikele ekulimaleni kwe-oxidative.
Ukuntuleka kwe-plasmalogens kungaholela ezinkingeni zokukhula kwezinzwa, ukuphazamiseka kwe-metabolic, kanye nokungenwa kalula kwezifo ze-neurodeergenerative. Ngakho-ke, kubalulekile ukugcina amazinga anele alawa ma-lipids emzimbeni ukuze kuqinisekiswe ukusebenza kahle kwesistimu yezinzwa kanye nempilo yonke.
Yini ama-cerebrosides? Isakhiwo kanye Nemisebenzi.
I-Cerebrosides wuhlobo lwe-glycolipid olutholakala ngokuyinhloko ebuchosheni nasemangqamuzaneni ezinzwa. Aqukethe i-fatty acid exhunywe ku-molecule ye-glucose ngesibopho se-glycosidic. Lawa ma-lipids adlala indima ebalulekile ekwakhekeni kwe-myelin sheath, ungqimba oluvikelayo oluzungeza ama-neurons futhi lusize ukudluliswa kwemizwa yezinzwa.
Ngaphezu kwalokho, ama-cerebrosides abandakanyeka ekulawulweni kokukhula kwamangqamuzana, ukuxhumana phakathi kwamaselula, kanye nokusabela kokuzivikela komzimba. Futhi zisebenza njengezinqolobane zamandla futhi njengezingxenye zesakhiwo solwelwesi lwamaseli ohlelweni lwezinzwa.
Ngakho-ke, ama-cerebrosides adlala indima ebalulekile ekusebenzeni kobuchopho, ukudluliselwa kwesignali yezinzwa, kanye nempilo yesistimu yezinzwa jikelele. Ukuqinisekisa ukudla okwanele kwalawa ma-lipids kubalulekile ukuze kuthuthukiswe impilo enhle yobuchopho futhi kuvinjwe ukuphazamiseka kwemizwa.
Yini ama-cerebrosides? Isakhiwo kanye Nemisebenzi
Ama-Cerebrosides ayiqembu lama -glycosphingolipid asebenza emzimbeni womuntu nowesilwane njengezingxenye ze-nerve kanye ne-muscle cell membranes, kanye nesistimu yezinzwa (ephakathi kanye neyangaphandle) ngokujwayelekile.
Ngaphakathi kwe-sphingolipids, ama-cerebrosides abizwa ngokusemthethweni ngokuthi i-monoglycosylceramides.
Lezi zingxenye zamangqamuzana zitholakala ngobuningi emgodleni we-myelin wezinzwa, okuyi-multilaminar enamathelayo eyakhiwe izingxenye zamaprotheni ezizungeze ama-axon e-neuronal ohlelweni lwezinzwa lomuntu.
Ama-Cerebrosides ayingxenye yeqembu elikhulu lama-lipids asebenza ohlelweni lwezinzwa. Iqembu le-sphingolipids lidlala indima ebalulekile njengezingxenye ze-membrane, ezilawula amandla abo futhi zenze ingxenye yezakhiwo zabo zangaphakathi ngemisebenzi yazo.
Ngaphezu kwama-cerebrosides, amanye ama-sphingolipids afakazele ukuthi abaluleke kakhulu ekudluliselweni kwesignali ye-neuronal nokuqashelwa kwendawo yeseli.
I-Cerebrosides yatholwa kanye neqembu lamanye ama-sphingolipids yiJalimane u-Johann LW Thudichum ngo-1884. Kuze kube yileso sikhathi, kwakungenakwenzeka ukuthola umsebenzi othize abawenzile, kodwa baqala ukuba nombono mayelana nezakhiwo ezakha lezi zinhlanganisela zamangqamuzana.
Kubantu, ukuwohloka kwezakhi ze-lipid, njenge-cerebrosides, kungabangela izifo ezingasebenzi ezingathinta ezinye izitho zomzimba.
Izifo ezinjenge-bubonic plague noma i-Black Death ziye zabangelwa izimpawu ezibangelwa ukuwohloka nokuwohloka kwe-galactosylcerebrosides.
Isakhiwo seCerebroside
Isici esibaluleke kakhulu nesiyisisekelo esakhiweni se-cerebrosides i-ceramide, umndeni wama-lipids owakhiwa ama-fatty acids nokuhluka kwekhabhoni esebenza njenge-molecule eyisisekelo kuwo wonke amanye ama-sphingolipids.
Ngenxa yalesi sizathu, amagama ezinhlobo ezahlukene ze-cerebrosides ane-ceramide egameni lawo, njenge-glucosylceramides (glycosylcerebrosides) noma i-galactosylceramides (galactosylcerebrosides).
I-Cerebrosides ibhekwa njenge-monosaccharides. Ushukela osele unamathiselwe ku-molecule ye-ceramide ewahlanganisa ngesibopho se-glycosidic.
Kuye ngokuthi iyunithi kashukela iyi-glucose noma i-galactose, izinhlobo ezimbili ze-cerebrosides zingakhiqizwa: i-glucosylcerebosides (i-glucose) ne-galactosylcerebrosides (i-galactose).
Kulezi zinhlobo ezimbili, i-glucosylcerebrosides yilezo izinsalela ze-monosaccharide ziyi-glucose futhi ngokuvamile zitholakala futhi zisakazwe kumathishu angewona ama-neuronal.
Ukunqwabelana kwawo ngokweqile endaweni eyodwa (amangqamuzana noma izitho) kuqala izimpawu zesifo i-Gaucher, esidala izimo ezinjengokukhathala, ukuphelelwa igazi kwegazi kanye ne-hypertrophy yezitho ezifana nesibindi.
I-Galactosylcerebrides inokwakheka okufanayo neyangaphambili, ngaphandle kokuba khona kwegalactose njengensalela ye-monosaccharide esikhundleni se-glucose.
Ngokuvamile lezi zisatshalaliswa kuzo zonke izicubu ze-neuronal (ezimele u-2% wento empunga kuze kufike ku-12% wento emhlophe) futhi zisebenza njengezimpawu zokusebenza kwama-oligodendrocyte, amangqamuzana abhekene nokwakheka kwe-myelin.
Ama-Glycosylcerebrosides nama-galactosylcebrosides nawo angahlukaniswa ngezinhlobo zamafutha acid ama-molecule awo aqukethe: i-lignoceric (uphalafini), i-cerebronic (phrenosin), i-nervonic (nerve), i-oxynervonic (oxynervon).
Ama-Cerebrosides angakwazi ukuhambisana nemisebenzi yawo enkampanini yezinye izakhi, ikakhulukazi ezicutshini ezingezona ze-neuronal.
Isibonelo salokhu ukuba khona kwe-glycosylcerebrosides ku-lipids yesikhumba, esiza ukuqinisekisa ukuthi isikhumba siyangena emanzini.
I-synthesis kanye nezakhiwo ze-cerebrosides
Ukwakheka kanye nokuhlanganiswa kwe-cerebrosides kwenziwa ngenqubo yokunamathela noma ukudluliselwa okuqondile koshukela (i-glucose noma i-galactose) isuka ku-nucleotide iye ku-molecule ye-ceramide.
I-biosynthesis ye-glycosylcerebrosides noma i-galactosylcerebrosides ivela ku-endoplasmic reticulum (yeseli ye-eukaryotic) kanye nolwelwesi lwe-Golgi apparatus.
Ngokomzimba, ama-cerebrosides abonisa ezawo izimfanelo ezishisayo nokuziphatha. Ngokuvamile banendawo yokuncibilika ephakeme kakhulu kunezinga lokushisa lomzimba womuntu elivamile, elibonisa isakhiwo sekristalu ewuketshezi.
Ama-cerebrosides anamandla okwenza amabhondi e-hydrogen afinyelela kwayisishiyagalombili ukusuka kumabhulokhi wokwakha we-ceramide njenge-sphingosine.
Lokhu kudalwa kuvumela izinga eliphezulu lokuhlangana phakathi kwama-molecule, akhiqize amazinga awo okushisa angaphakathi.
Kanye nezinto ezifana ne-cholesterol, ama-cerebrosides asiza ekuhlanganisweni kwamaprotheni nama-enzyme.
Ukucekelwa phansi kwemvelo kwe-cerebrosides kuqukethe inqubo yokudilizwa noma ukuhlukaniswa kwezingxenye zayo. Lokhu kwenzeka ku-lysosome, enesibopho sokuhlukanisa i-cerebroside ibe ushukela, i-sphingosine, ne-fatty acid.
Cerebrosides kanye nezifo
Njengoba kushiwo ngaphambili, ukuguga nokuklebhuka kwama-cerebrosides, kanye nokuqoqwa kwawo ngokweqile endaweni eyodwa yohlelo lomuntu nezilwane eziphilayo kanye nesimiso samangqamuzana, ngokwesibonelo, kungadala izimo ngaleso sikhathi ezazingaqeda ingxenye yesithathu yabantu basezwekazini laseYurophu, isibonelo.
Ezinye zezifo ezibangelwa ukukhubazeka ekusebenzeni kwe-cerebrosides zibhekwa njengefa.
Endabeni yesifo sikaGaucher, esinye sezimbangela zaso eziyinhloko ukungabikho kwe-glucocerebrocidase, i-enzyme enganciphisa ukuqoqwa kwamafutha.
Lesi sifo asibhekwa njengekhambi futhi, kwezinye izimo, ukuqala kwaso kusenesikhathi (ezinganeni ezisanda kuzalwa, isibonelo) cishe ngaso sonke isikhathi simelela umphumela obulalayo.
Esinye sezifo ezivame kakhulu, umphumela wokukhubazeka ku-galactosylcerebrosides, yisifo se-Krabbe, esichazwa njengokwehluleka ukungasebenzi kwediphozithi ye-lysosomal, okukhiqiza ukunqwabelana kwama-galactosylcerebrosides athinta i-myelin sheath futhi, ngenxa yalokho, udaba olumhlophe lwesistimu yezinzwa, okubangela ukuphazamiseka okunganqandeki.
Njengoba kubhekwa njengefa, ungazalwa unesifo se-Krabbe futhi uqale ukukhombisa izimpawu phakathi kwezinyanga zokuqala ezintathu neziyisithupha ubudala.
Okuvame kakhulu yilezi: ukuqina kwezitho zomzimba, imfiva, ukucasuka, ukuquleka nokukhula kancane kwamakhono emoto nengqondo.
Ngezinga elihluke kakhulu kubantu abasha nakubantu abadala, isifo se-Krabbe singase futhi sibangele izimo ezimbi kakhulu, njengobuthakathaka bemisipha, ukungezwa, i-optic atrophy, ubumpumputhe, nokukhubazeka.
Ikhambi alikatholakali, nakuba ukufakelwa komnkantsha kubhekwa njengokusiza ekwelapheni. Izingane ezincane zinezinga eliphansi lokusinda.
Izinkomba
- I-Medline Plus (sf). Isifo sikaGaucher . Kutholwe ku-Medline Plus: medlineplus.gov
- O'Brien, J. S., & Rouser, G. (1964). Ukwakheka kwe-acid enamafutha e-sphingolipids yobuchopho: i-sphingomyelin, i-ceramide, i-cerebroside, ne-cerebroside sulfate. Ijenali yocwaningo lweLipid , I-339-342.
- O'Brien, J. S., Fillerup, D. L., & Mead, J. F. (1964). I-Brain lipids: I. Ukulinganisa kanye nokwakheka kwe-asidi enamafutha ye-cerebroside sulfate ku-cerebral cerebral grey grey and white matter. Ijenali yocwaningo lweLipid , I-109-116.
- Ihhovisi Lezokuxhumana Nokuxhumana Nomphakathi; I-National Institute of Neurological Disorders and Stroke; Izikhungo Zezempilo Zikazwelonke. (Disemba 20, 2016). Ulwazi ngezifo zokugcinwa kwe-lipid . Kubuyiswe ku-National Institute of Neurological Disorders and Stroke: ninds.nih.gov
- Ramil, JS (n.d.). I-lipids