{"id":6412,"date":"2026-10-19T09:48:52","date_gmt":"2026-10-19T09:48:52","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-lif-og-laeknavisindum-fatich-mechmet\/"},"modified":"2026-10-19T09:48:52","modified_gmt":"2026-10-19T09:48:52","slug":"doktorsvorn-i-lif-og-laeknavisindum-fatich-mechmet","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-lif-og-laeknavisindum-fatich-mechmet\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed l\u00edf og l\u00e6knav\u00edsindum – Fatich Mechmet"},"content":{"rendered":"
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M\u00e1nudaginn 22. september 2025 ver Fatich Mechmet doktorsritger\u00f0 s\u00edna \u00ed l\u00edf- og l\u00e6knav\u00edsindum vi\u00f0 L\u00e6knadeild H\u00e1sk\u00f3la \u00cdslands. Ritger\u00f0in ber heiti\u00f0: Hlutverk MITF \u00ed taugafrumum lyktarklumbunnar:\u00a0 Markgen \u00ed lyktarklumbu og \u00e1hrif \u00e1 \u00f6ldrun. Role of MITF in olfactory bulb neurons:\u00a0 Putative MITF target genes in neurons and the effects of its loss in the aging olfactory bulb.<\/strong><\/p>\n

Andm\u00e6lendur eru dr. Alexander Fleischman, d\u00f3sent vi\u00f0 Brown University, Rhode Island, og S\u00e6var Ing\u00fe\u00f3rsson, d\u00f3sent vi\u00f0 Hj\u00fakrunar-og lj\u00f3sm\u00f3\u00f0urfr\u00e6\u00f0ideild H\u00e1sk\u00f3la \u00cdslands.<\/p>\n

Umsj\u00f3narkennari og lei\u00f0beinandi var P\u00e9tur Henry Petersen, pr\u00f3fessor og me\u00f0lei\u00f0beinandi Eir\u00edkur Steingr\u00edmsson, pr\u00f3fessor. Auk \u00deeirra s\u00e1tu \u00ed doktorsnefnd Margr\u00e9t Helga \u00d6gmundsd\u00f3ttir, pr\u00f3fessor, Ragnhildur \u00de\u00f3ra K\u00e1rad\u00f3ttir, pr\u00f3fessor og Sigr\u00ed\u00f0ur Rut Franzd\u00f3ttir, d\u00f3sent.<\/p>\n

S\u00e6d\u00eds S\u00e6varsd\u00f3ttir, pr\u00f3fessor og deildarforseti L\u00e6knadeildar, stj\u00f3rnar ath\u00f6fninni sem fer fram \u00ed H\u00e1t\u00ed\u00f0asal H\u00e1sk\u00f3la \u00cdslands og hefst kl. 13.00.<\/p>\n

\u00c1grip <\/strong><\/p>\n

Umritunar\u00fe\u00e1tturinn MITF (Microphthalmia-tengdur umritunar\u00fe\u00e1ttur) gegnir lykilhlutverki \u00ed tilur\u00f0 og starfsemi litfrumna og\u202fmastfrumna \u00ed seild\u00fdrum. Mitf-geni\u00f0 er einnig tj\u00e1\u00f0 \u00ed\u00a0 taugafrumum\u202f lyktarklumbunnar \u00ed mi\u00f0taugakerfi m\u00fasarinnar. Hlutverk \u00feess \u00fear er \u00f3\u00feekkt, en \u00e1n Mitf-gensins s\u00fdna m\u00edtur- og br\u00faskfrumur (M\/T-frumur) lyktarklumbunnar aukna taugavirkni \u00ed frumur\u00e6kt. \u00c1hrif \u00e1 lyktarskyn eru takm\u00f6rku\u00f0.\u00a0<\/p>\n

Tilgangur \u00feessarar ranns\u00f3knar var a\u00f0 au\u00f0kenna markgen MITF \u00ed M\/T frumum \u00ed lyktarklumbu m\u00fasa. \u00dea\u00f0 var gert me\u00f0 \u00fev\u00ed a\u00f0 greina tj\u00e1ningu gena \u00ed m\u00fasum sem skortir MITF-pr\u00f3teini\u00f0 og bindingu MITF vi\u00f0 m\u00f6guleg st\u00fdrisv\u00e6\u00f0i \u00feeirra \u00ed \u00f6\u00f0rum frumuger\u00f0um. Ni\u00f0urst\u00f6\u00f0urnar s\u00fdndu a\u00f0 \u00feau gen sem eru l\u00edkleg til a\u00f0 vera undir stj\u00f3rn MITF \u00ed taugafrumum eru almennt ekki \u00feau s\u00f6mu og \u00ed \u00f6\u00f0rum frumuger\u00f0um. \u00deau m\u00e1 flokka \u00ed tvo undirh\u00f3pa: \u00feau sem l\u00edklega hamla taugavirkni og \u00feau sem eru s\u00e9rt\u00e6k fyrir undirflokk br\u00faskfrumna, svokalla\u00f0ar mi\u00f0-br\u00faskfrumur. Fj\u00f6ldi \u00feeirra var l\u00e6gri \u00e1n MITF-gensins. \u00deetta bendir til \u00feess a\u00f0 MITF hafi minnst tv\u00ed\u00fe\u00e6tt hlutverk \u00ed lyktarklumbunni \u2013 a\u00f0 taka \u00fe\u00e1tt \u00ed stj\u00f3rnun taugavirkni og tilur\u00f0 og starfsemi mi\u00f0ju-br\u00faskfrumna. Frumur \u00feessar hafa s\u00e9rstakar tengingar vi\u00f0 sv\u00e6\u00f0i \u00ed framheila, \u00fe\u00e6r eru \u00f3l\u00edkar m\u00edturfrumum og \u00fev\u00ed er m\u00f6gulegt a\u00f0 MITF hafi hlutverki a\u00f0 gegna \u00ed tengingum mi\u00f0jubr\u00fask-frumna vi\u00f0 \u00f6nnur sv\u00e6\u00f0i innan mi\u00f0taugakerfisins.\u00a0\u00a0<\/p>\n

\u00d6ldrun hefur \u00e1hrif \u00e1\u00a0 skynkerfi heilans, \u00fear \u00e1 me\u00f0al lyktarklumbuna, og lyktarskyn minnkar me\u00f0 aldrinum. Tap \u00e1 lyktarskyni er einnig tengt vi\u00f0 fyrstu einkenni taugahr\u00f6rnunarsj\u00fakd\u00f3ma eins og Alzheimers- og Parkinsons-sj\u00fakd\u00f3ms. Undirliggjandi orsakir \u00feess eru \u00fe\u00f3 \u00f3lj\u00f3sar. Aukin taugavirkni er oft fyrsta skrefi\u00f0 \u00ed \u00e1tt a\u00f0 taugahr\u00f6rnun. \u00dear sem taugafrumur \u00far ungum m\u00fasum sem ekki tj\u00e1 MITF s\u00fdna auka virkni var \u00e1kve\u00f0i\u00f0 a\u00f0 athuga hvort taugahr\u00f6rnun \u00e6tti s\u00e9r sta\u00f0 \u00ed lyktarklumbu \u00feeirra me\u00f0 h\u00e6kkandi aldri.\u00a0<\/p>\n

Ni\u00f0urst\u00f6\u00f0urnar s\u00fdndu a\u00f0 gamlar Mitf-st\u00f6kkbreyttar m\u00fds eru me\u00f0 skerta lyktargetu en engin merki um b\u00f3lgur e\u00f0a f\u00e6kkun taugafrumna. \u00cd lyktarklumbu aldra\u00f0ra Mitf-st\u00f6kkbreyttra m\u00fasa j\u00f3kst tj\u00e1ning gena sem tj\u00e1 fyrir undireiningum kal\u00edumganga. Almennt veldur aukin tj\u00e1ning sl\u00edkra gena minni taugavirkni og \u00feetta bendir \u00fev\u00ed til \u00feess a\u00f0 \u00feessi breyting \u00ed tj\u00e1ningu g\u00e6ti tempra\u00f0 e\u00f0a minnka\u00f0 taugavirkni \u00ed lyktarklumbunni og \u00feannig unni\u00f0 gegn taugahr\u00f6rnun.<\/p>\n

Abstract <\/strong><\/p>\n

Microphthalmia-associated transcription factor (MITF) is a master regulator in melanocytes and plays and important role in mast cells. Mitf is also expressed in the mitral and tufted (M\/T) cells which are projection neurons (PNs), in the olfactory bulb (OB). Lack of MITF leads to neuronal hyperactivity in primary M\/T cells but the general function of MITF in neurons is currently unknown.<\/p>\n

In this study, putative MITF target genes in M\/T cells of mice were identified. They differ from target genes in other cell types including melanocytes and can be grouped into two categories: those likely to be involved in inhibiting neuronal activity and those specific to a subgroup of tufted called middle tufted cells (mTCs). This work also shows that the mTCs are reduced in number in the absence of Mitf, suggesting a role for Mitf in the generation or survival of the mTCs and\/or their function. Altered response to odors is also observed in Mitfmi-vag9\/mi-vga9 mice, indicating a role of MITF in olfactory adaptation.<\/p>\n

Aging affects various brain structures and sensory systems, including the OB, resulting in a decline in olfactory ability. Decline in the OB is associated with early signs of neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. However, the underlying reasons remain unclear. Primary PNs from OBs of young Mitfmi-vga9\/mi-vga9 mice show hyperactivity, potentially linked to reduced expression of the potassium channel subunit Kcnd3\/Kv4.3, which impacts intrinsic plasticity. In aged Mitfmi-vag9\/mi-vag9 mice, reduced olfactory ability was observed without any signs of neuroinflammation or reduction in neuronal number. An increase in the expression of genes coding for potassium channel subunits was found in the OBs of aged Mitfmi-vga9\/mi-vga9 mice. This suggests that increased expression of potassium channel subunits in aging Mitfmi-vga9\/mi-vga9 mice may compensate for or stabilize neuronal hyperactivity observed in the OB of young Mitfmi-vga9\/mi-vga9 mice.<\/p>\n

Um doktorsefni<\/strong><\/p>\n

Fatich Mechmet f\u00e6ddist \u00e1ri\u00f0 1991 \u00ed Komotini, \u00ed Nor\u00f0austur-Grikklandi. Hann lauk n\u00e1mi af n\u00e1tt\u00farufr\u00e6\u00f0ibraut framhaldssk\u00f3la \u00ed Komotini \u00e1ri\u00f0 2008. Fatich lauk B.Sc. pr\u00f3fi \u00ed sameindal\u00edffr\u00e6\u00f0i og erf\u00f0afr\u00e6\u00f0i fr\u00e1 H\u00e1sk\u00f3lanum \u00ed Istanb\u00fal \u00ed Tyrklandi \u00e1ri\u00f0 2013 og meistarapr\u00f3fi \u00ed d\u00fdral\u00edft\u00e6kni fr\u00e1 School of Agriculture and Veterinary Medicine vi\u00f0 H\u00e1sk\u00f3lann \u00ed Bologna \u00e1 \u00cdtal\u00edu. Meistararitger\u00f0 hans var \u00e1 svi\u00f0i taugav\u00edsinda. \u00c1ri\u00f0 2017 starfa\u00f0i Fatich sem ungur v\u00edsindama\u00f0ur vi\u00f0 Algarve Biomedical Research Institute \u00ed Port\u00fagal, \u00ed ranns\u00f3knarh\u00f3pi um sameindataugav\u00edsindi og gename\u00f0fer\u00f0. Hann h\u00f3f doktorsn\u00e1m \u00ed taugav\u00edsindum vi\u00f0 H\u00e1sk\u00f3la \u00cdslands \u00e1ri\u00f0 2018. Ranns\u00f3knarverkefni hans hlaut styrk \u00far Ranns\u00f3knasj\u00f3\u00f0i og Eimskipasj\u00f3\u00f0i H\u00e1sk\u00f3la \u00cdslands. Samhli\u00f0a doktorsn\u00e1mi hlaut Fatich styrk sem a\u00f0sto\u00f0arkennari fyrir doktorsnema og t\u00f3k \u00fe\u00e1tt \u00ed kennslu vi\u00f0 H\u00e1sk\u00f3lann.Fr\u00e1 \u00e1rinu 2023 hefur Fatich starfa\u00f0 sem yfirl\u00edffr\u00e6\u00f0ingur hj\u00e1 l\u00edft\u00e6knifyrirt\u00e6ki \u00ed Reykjav\u00edk.<\/p>\n<\/div><\/div>","protected":false},"featured_media":5798,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_phd_date_start":"2025-09-22T13:00:00+00:00","_phd_date_end":"2025-09-22T16:00:00+00:00","_phd_location":"A\u00f0albygging H\u00e1t\u00ed\u00f0asalur","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"Hlutverk MITF \u00ed taugafrumum lyktarklumbunnar: Markgen \u00ed lyktarklumbu og \u00e1hrif \u00e1 \u00f6ldrun. 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