Spremembe v metilaciji DNK, povezane s periodičnim vročinskim sindromom z aftami, tonzilitisom in adenitisom

Lovšin, Ema (author), Avčin, Tadej (mentor), DEBELJAK, MARUŠA (co-mentor)

Periodični vročinski sindrom z aftami, tonzilitisom in adenitisom (sindrom PFAPA) je avtoinflamatorna bolezen in je najpogostejši periodični vročinski sindrom v pediatrični populaciji. PFAPA, ki si deli določene lastnosti z monogenskimi vročinskimi sindromi je trenutno vzročno še nepojasnjena. Klinična podobnost genetskim sindromom in pogostejše pojavljanje v nekaterih družinah, kažeta na možno genetsko nagnjenost k bolezni. Raziskave kažejo, da gre pri PFAPA najverjetneje za kombinacijo več genetskih in okoljskih dejavnikov. Za sindrom je značilno, da spontano izzveni, kar nakazuje, da je mehanizem, ki vzdržuje ali sproži bolezen prehodne narave. Sum na to, da sindrom PFAPA bolezen genetskega izvora in hkrati, da je mehanizem bolezni verjetno prehodne narave, kaže v smeri metilacije DNK, kot možnem patogenetskem mehanizmu. Primerjali smo razlike v metilaciji DNK med bolniki s sindromom PFAPA in zdravimi otroci na ravni genoma z metodama MeDIP in MBD. Raziskava je pokazala, da so pri otrocih s sindromom PFAPA prisotne spremembe v metilaciji DNK. Identificirali smo 24 genomskih regij, ki so pri bolnikih hiper- ali hipometilirane v primerjavi z zdravimi otroci. Med identificiranimi regijami ni bilo statistično značilne obogatitve za določen biološki proces ali molekularno funkcijo. Regije smo povezali z geni, ki sodelujejo pri vnetnih procesih in procesih diferenciacije imunskih celic, ne pa tudi z geni, ki so povezani z razvojem monogenskih avtoinflamatornih bolezni. Rezultate smo uspešno potrdili z metodo MSRE-qPCR na izbranih regijah. Kljub temu, da vpliv spremenjene metilacije DNK pri bolnikih s sindromom PFAPA ostaja zaenkrat še nepojasnjen, rezultati kažejo, da bi bil sindrom lahko posledica spremenjenih vzorcev metilacije, verjetno povzročenih z okoljskimi vplivi, kot so na primer okužbe. Ugotovljene razlike med bolniki s sindromom PFAPA in zdravimi otroci kažejo na novo in še neznano vlogo metilacije DNK pri razvoju sindroma PFAPA in tudi drugih kompleksnih in še nepojasnjenih imunskih bolezni.

• Language: Slovenian
• Keywords: sindrom PFAPA, metilacija DNK, epigenetika, MeDIP, MBD
• Work type: Doctoral dissertation
• Organization: MF - Faculty of Medicine
• Year: 2023
• PID: 20.500.12556/RUL-145276
• Publication date in RUL: 15.04.2023

Secondary language

• Language: English
• Title: Changes in DNA methylation associated with Periodic Fever, Aphthous Stomatitis, Pharyngitis and Adenitis Syndrome

Abstract

Periodic fever, aphthous stomatitis, pharyngitis and adenitis (PFAPA) syndrome is an autoinflammatory disease and the most common periodic fever syndrome in the paediatric population. PFAPA, which shares certain similarities with monogenic fever syndromes, is currently etiologically unexplained. Clinically similar periodic fever syndromes are of genetic nature, which together with the fact that PFAPA clusters in some families, suggests a possible genetic predisposition of the PFAPA syndrome. Published data show that PFAPA is most likely caused by a combination of several genetic and environmental factors. The syndrome is characterized by spontaneous resolution, suggesting that the mechanism which maintains or triggers the disease is transient in nature. The suspicion that PFAPA syndrome is caused by a genetic mechanism and that the mechanism of the disease is likely to be transient, both point in the direction of DNA methylation as a possible pathogenetic mechanism. We compared DNA methylation profiles between patients with PFAPA syndrome and healthy children at the genome level, using enrichment methods MeDIP and MBD. The study showed that there are changes in DNA methylation patterns in children with PFAPA syndrome compared to healthy children. We identified 24 genomic regions that were hyper- or hypomethylated in patients as compared to healthy children of similar age, however, there was no statistically significant enrichment of a particular biological process or molecular function. Regions were annotated to the genes involved in inflammatory and immune cell differentiation processes, but not with the genes associated with the development of monogenic autoinflammatory diseases. We successfully confirmed the results with MSRE-qPCR. Although the impact of altered DNA methylation in patients with PFAPA syndrome remains unclear, our study suggests that the syndrome could be caused by altered methylation patterns, probably caused by environmental influences such as infection. The identified differences between patients with PFAPA syndrome and healthy children point to a possible new role of DNA methylation in the development of PFAPA syndrome as well as other complex and unexplained immune diseases.

• Keywords: PFAPA syndrome, DNA methylation, epigenetics, MeDIP, MBD