MikroRNA-d keratinotsüütide rakulise vastuse reguleerimisel naastulise psoriaasi ja atoopilise dermatiidi korral

Väitekirja elektrooniline versioon ei sisalda publikatsiooneNahk on meie organismi suurim organ, mis kaitseb meid väliskeskkonna mõjude eest. Häired naharakkude omavahelises suhtlemises ja kaitsefunktsioonis võivad viia erinevate põletikuliste nahahaiguste välja kujunemiseni. Psoriaas ja atoopiline dermatiit on ühed sagedasemad kroonilised põletikulised nahahaigused. Psoriaasi sagedus on keskmiselt 2-3% ning atoopilise dermatiidil täiskasvanutel 2-5% ja lastel isegi kuni 20%. Psoriaasi kirjeldab punane põletikuline selgelt piiritletavate laikudega kestendav lööve. Atoopilist dermatiiti iseloomustab põletikune sügelev lööve. Neid haigusi põdevate patsientide elukvaliteet on langenud ja samuti esinevad neil mitmed kaasuvad haigused, nagu näiteks psoriaatiline artriit, südameveresoonkonna haigused ja vaimsed probleemid. Mõlemate haigusi väljakujunemisel on kaasatud naharakud, mis on võimelised tootma signaalmolekule, mis mõjutavad immuunrakkude liikumist ja aktiivsust nahas ning immuunrakud omakorda mõjutavad naha rakke. Tulemusena kujunebki psoriaasile ja atoopilisele dermatiidile iseloomulik kliiniline pilt. miRNA-d on lühikesed RNA molekulid, mis reguleerivad väga suure hulga geenide ekspressiooni rakkudes. Töös kirjeldati miR-146a ja miR-146b (miR-146a/b) ning miR-10a funktsioone naha rakkudes vastavalt seoses psoriaasi või atoopilise dermatiidiga. Eelnevalt oli näidatud, et miR-146a on võimelised alla suruma põletikulisi protsesse nahas, kuid miR-146b ja miR-10a roll naha rakkudes oli teadmata. Leidsime, et psoriaasis patsientide nahas on miR-146a/b tase suurenenud ja need suruvad alla selliste geenide taset, mis omakorda mõjutavad põletikulisi protsesse ja naharakkude jagunemist. Näitasime, et läbi selle pärsivad miR-146a/b psoriaasile iseloomulikke rakulisi protsesse, kuid miR-146a/b kõrgem ekspressioon nahas psoriaasi korral ei ole suutelised haiguse väljakujunemist ära hoidma. Teiseks tuvastasime miR-10a suurenenud taseme atoopilise dermatiidi patsientide nahas. Leidsime, et miR-10a tase naharakkudes sõltub rakkude diferentseerumise staadiumist ning et miR-10a peamiseks rolliks on naharakkude jagunemise aeglustamine ning lisaks surub miR-10a alla naharakkudes põletikulisi protsesse. Seetõttu võib oletada, et miR-10a mõjutab atoopilise dermatiidi teket ja kulgu.The skin is the largest organ in our body that protects us from the outside environment. Dysfunction in the interaction and protective functions of the skin cells can lead to the development of various inflammatory skin diseases. Psoriasis and atopic dermatitis are among the most common chronic inflammatory skin diseases. The incidence of psoriasis is on average 2-3% and in atopic dermatitis 2-5% in adults and even up to 20% in children. Psoriasis is characterized by a red inflammatory rash with scaly patches. Atopic dermatitis is characterized by an inflammatory itchy rash. Patients with these diseases have a reduced quality of life and also have several co-morbidities, such as psoriatic arthritis, cardiovascular disease, and mental health problems. The development of both diseases involves the skin cells that are capable of producing signaling molecules that affect the movement and activity of immune cells in the skin, and immune cells in turn affect skin cells. The result is a clinical phenotype seen in psoriasis and atopic dermatitis. miRNAs are short RNA molecules that regulate the expression of a very large number of genes in cells. In this thesis, the functions of miR-146a and miR-146b (miR-146a / b) and miR-10a in skin cells in relation to psoriasis or atopic dermatitis, respectively, were described. MiR-146a has previously been shown to be able to suppress inflammatory processes in the skin, but the role of miR-146b and miR-10a in skin cells was unknown. We found that the levels of miR-146a/b in the skin of patients with psoriasis were increased and suppressed the levels of genes that in turn affect inflammatory processes and the division of skin cells. We have shown that miR-146a/b inhibits the cellular processes characteristic to psoriasis, however, the higher expression of miR-146a/b in the skin of psoriasis patients is not able to prevent the development of the disease. Secondly, we detected elevated levels of miR-10a in the skin of atopic dermatitis patients. We found that the level of miR-10a in skin cells depends on the stage of cell differentiation and that the main role of miR-10a is to slow down the division of skin cells and, also, to suppress inflammatory processes in skin cells. Therefore, it can be hypothesized that miR-10a affects the development and course of atopic dermatitis.https://www.ester.ee/record=b537104

Impact of AHR Ligand TCDD on Human Embryonic Stem Cells and Early Differentiation

Aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor, which mediates the effects of a variety of environmental stimuli in multiple tissues. Recent advances in AHR biology have underlined its importance in cells with high developmental potency, including pluripotent stem cells. Nonetheless, there is little data on AHR expression and its role during the initial stages of stem cell differentiation. The purpose of this study was to investigate the temporal pattern of AHR expression during directed differentiation of human embryonic stem cells (hESC) into neural progenitor, early mesoderm and definitive endoderm cells. Additionally, we investigated the effect of the AHR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the gene expression profile in hESCs and differentiated cells by RNA-seq, accompanied by identification of AHR binding sites by ChIP-seq and epigenetic landscape analysis by ATAC-seq. We showed that AHR is differentially regulated in distinct lineages. We provided evidence that TCDD alters gene expression patterns in hESCs and during early differentiation. Additionally, we identified novel potential AHR target genes, which expand our understanding on the role of this protein in different cell types

miRNA expression profiles of the perilesional skin of atopic dermatitis and psoriasis patients are highly similar

Abstract Atopic dermatitis (AD) and psoriasis vulgaris (PV) are chronic inflammatory skin diseases with heterogeneous molecular backgrounds. MicroRNAs (miRNAs) contribute to either development or regulation of many immune system related diseases. Only few miRNA profiling studies are available for AD and no comparisons between AD and PV skin miRNA profiles have been performed recently. We conducted a miRNA profiling analysis of skin, as well as serum, from adult AD and PV patients and control individuals. 130 miRNAs were differentially expressed in AD skin, of which 77 were common differentially expressed in AD and PV. No differentially expressed miRNAs were detected in serum. Pathway analyses revealed differentially expressed miRNAs to potentially target immune-system related pathways, including TNF-α, IL-2/STAT4 and IL-6/JAK/STAT3. Additional genetic analysis of published AD GWAS dataset detected association of several target genes of differentially expressed miRNAs in skin. Moreover, miR-28-5p, miR-31-5p, miR-378a-3p and miR-203a were validated as upregulated in the skin of AD and PV patients. All validated miRNAs were reliable predictive markers for AD or PV. In conclusion, miRNA expression pattern in the skin of adult AD patients is highly similar to that of PV with multiple differentially expressed miRNAs potentially involved in the regulation of immune responses in AD and PV

miR‐10a‐5p is increased in atopic dermatitis and has capacity to inhibit keratinocyte proliferation

BACKGROUND: miR-10a-5p has been shown to regulate cancer cell proliferation and invasiveness and endothelial cell inflammatory responses. The function of miR-10a-5p in the skin has not been previously studied. The aim of the current study was to examine miR-10a-5p expression, regulation, and function in keratinocytes (KCs) in association with atopic dermatitis (AD). METHODS: The expression of miR-10a-5p and its target genes was analyzed using RT-qPCR, mRNA array analysis, in situ hybridization, and immunofluorescence. The transfection of miRNA mimics, cell cycle distribution analysis, and luciferase assays was used to study miR-10a-5p functions in human primary KCs. RESULTS: miR-10a-5p was found to be upregulated in lesional skin from patients with AD and in proliferating KCs. Array and pathway analysis of IL-1β-stimulated KCs revealed that miR-10a-5p inhibited many genes that affect cell cycle progression and only a few inflammation-related genes. Accordingly, fewer cells in S-phase and reduced proliferation were detected as characteristics of miR-10a-5p-transfected KCs. The influence of miR-10a-5p on cell proliferation was also evident in KCs induced by AD-related cytokines, including IL-4, IL-17, and IL-1β, as measured by the capacity to strongly suppress the expression of the proliferation marker Ki-67. Among AD-related putative direct target genes, we verified hyaluronan synthase 3, a damage-associated positive regulator of KC migration and proliferation, as a direct target of miR-10a-5p. CONCLUSIONS: miR-10a-5p inhibits KC proliferation and directly targets hyaluronan synthase 3 and thereby may modulate AD-associated processes in the skin