Analiza alternativne poliadenilacije RNA v hipotalamusu pri vitki in debeli selekcionirani mišji liniji : doktorska disertacija

Mikec, Špela (avtor), Kunej, Tanja (mentor), Horvat, Simon (komentor)

Debelost, ki je posledica kompleksne etiologije zaradi okoljskih in genetskih dejavnikov, predstavlja velik izziv v raziskavah in zdravstvu. Nekateri genetski dejavniki, ki prispevajo k debelosti in še niso bili podrobno raziskani, vključujejo poliadenilacijo mRNA (PA), ključen proces pri zorenju in uravnavanju mRNA. Geni z več mesti PA lahko zaradi alternativne poliadenilacije (APA) izražajo izooblike mRNA istega gena, ki se najpogosteje razlikujejo v dolžini 3' UTR, redkeje pa v kodirajočem zaporedju. Čeprav so spremembe v PA povezane z različnimi boleznimi, njihov prispevek k debelosti še ni dobro raziskan. Z metodo sekvenciranja mest zaključka transkripcije na ravni celotnega transkriptoma (WTTS-seq) smo analizirali APA mRNA v hipotalamusu, glavnem regulatorju energetske homeostaze, pri samcih debele in vitke selekcionirane linije miši, ki služita kot modela za poligeno debelost in vitkost. Geni z diferencialno izraženimi mesti (DE-PA) (n=357, FC ? |1,5|, padj < 0,05) so bili obogateni v bioloških poteh, povezanih z razvojem, uravnavanjem in delovanjem nevronov ter njihovih povezav, kar nakazuje na spremenjeno delovanje hipotalamičnih nevronov pri samcih debele linije v primerjavi z vitko linijo na HFD. Izpostavili smo 13 kandidatnih genov za debelost/adipoznost z dvema ali več mesti DE-PA, podprtimi tudi s podatkovnimi zbirkami, ki vodijo v nastanek diferencialno izraženih mRNA zaradi APA. Od tega je bilo pet genov predhodno povezanih z debelostjo (Pdxdc1, Rpl14, Copg1, Pcna in Stx3), ter osem novih kandidatnih genov (Ccdc25, Gm14403, Hlf, Mrpl3, Pisd-ps3, Sbsn, Slx1b in Spon1). Takšne raziskave molekularnih mehanizmov, ki vplivajo na zamaščenost in debelost, postavljajo temelje za razvoj ciljno usmerjenih in prilagojenih terapevtskih strategij za obvladovanje debelosti. V prihodnjih raziskavah bi bilo smiselno preučiti lokalizacijo in funkcionalnost izooblik mRNA zaradi APA predlaganih kandidatnih genov, s poudarkom na jedrih hipotalamusa, ki so ključna za uravnavanje energetske homeostaze.

• Jezik: Slovenski jezik
• Ključne besede: genetika, transkriptomika, mišji modeli, poliadenilacija, alternativna poliadenilacija, debelost, debela linija, vitka linija, hipotalamus, izooblike, mRNA, molekularni mehanizmi
• Vrsta gradiva: Doktorsko delo/naloga
• Tipologija: 2.08 - Doktorska disertacija
• Organizacija: BF - Biotehniška fakulteta
• Leto izida: 2024
• PID: 20.500.12556/RUL-166005
• COBISS.SI-ID: 219463939
• Datum objave v RUL: 17.12.2024

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Analysis of alternative RNA polyadenylation in hypothalamus of the lean and fat mouse selection lines : doctoral dissertation

Izvleček

Obesity, due to its complex aetiology caused by environmental and genetic factors, represents a major challenge in research and health care. Some of the genetic factors contributing to obesity that have not yet been studied in detail include polyadenylation of mRNA (PA), a key process in mRNA maturation and regulation. Due to alternative polyadenylation (APA) genes with multiple PA sites express mRNA isoforms of the same gene, which most commonly differ in the length of the 3′ UTR, and less frequently in the coding sequence. Although changes in PA are associated with various diseases, their contribution to obesity is not yet well understood. Using the whole transcriptome transcription termini site sequencing (WTTS-seq) method, we analysed APA of mRNA in the hypothalamus, the key regulator of energy homeostasis, in male Fat and Lean selection mouse lines serving as models for polygenic obesity and leanness. Genes with differentially expressed PA (DE-PA) sites (n=357, FC ≥ |1.5|, padj < 0.05) were enriched in biological pathways associated with the development, regulation and function of neurons and their connections, suggesting altered hypothalamic neuronal function in the Fat compared to Lean line males on HFD. We identified 13 candidate genes for obesity/adiposity with two or more DE-PA sites, supported by databases, that lead to differentially expressed mRNA isoforms due to APA. Of these, five genes previously associated with obesity (Pdxdc1, Rpl14, Copg1, Pcna and Stx3), and eight that represent novel candidate genes (Ccdc25, Gm14403, Hlf, Mrpl3, Pisd-ps3, Sbsn, Slx1b and Spon1). Such investigations into the molecular mechanisms underlying adiposity and obesity lay the foundations for the development of targeted and tailored therapeutic strategies for the management of obesity. In future studies, it would be sensible to investigate the localisation and functionality of mRNA isoforms due to APA of proposed candidate genes, with a focus on hypothalamic nuclei that are crucial for the regulation of energy homeostasis.

• Ključne besede: genetics, transcriptomics, mouse models, polyadenylation, alternative polyadenylation, obesity, fat line, lean line, hypothalamus, isoforms, mRNA, molecular mechanisms