Unraveling Transcriptome Profile, Epigenetic Dynamics, and Morphological Changes in Psoriasis-like Keratinocytes: "Insights into Similarity with Psoriatic Lesional Epidermis".

Keratinocytes are one of the primary cells affected by psoriasis inflammation. Our study aimed to delve deeper into their morphology, transcriptome, and epigenome changes in response to psoriasis-like inflammation. We created a novel cytokine mixture to mimic mild and severe psoriasis-like inflammatory conditions in cultured keratinocytes. Upon induction of inflammation, we observed that the keratinocytes exhibited a mesenchymal-like phenotype, further confirmed by increased VIM mRNA expression and results obtained from confocal microscopy. We performed RNA sequencing to achieve a more global view, revealing 858 and 6987 DEGs in mildly and severely inflamed keratinocytes, respectively. Surprisingly, we found that the transcriptome of mildly inflamed keratinocytes more closely mimicked that of the psoriatic epidermis transcriptome than the severely inflamed keratinocytes. Genes involved in the IL-17 pathway were a major contributor to the similarities of the transcriptomes between mildly inflamed KCs and psoriatic epidermis. Mild and severe inflammation led to the gene regulation of epigenetic modifiers such as HATs, HDACs, DNMTs, and TETs. Immunofluorescence staining revealed distinct 5-hmC patterns in inflamed versus control keratinocytes, and consistently low 5-mC intensity in both groups. However, the global DNA methylation assay detected a tendency of decreased 5-mC levels in inflamed keratinocytes versus controls. This study emphasizes how inflammation severity affects the transcriptomic similarity of keratinocytes to psoriatic epidermis and proves dynamic epigenetic regulation and adaptive morphological changes in inflamed keratinocytes.

Are the Cutaneous Microbiota a Guardian of the Skin's Physical Barrier? The Intricate Relationship between Skin Microbes and Barrier Integrity.

The skin is a tightly regulated, balanced interface that maintains our integrity through a complex barrier comprising physical or mechanical, chemical, microbiological, and immunological components. The skin's microbiota affect various properties, one of which is the establishment and maintenance of the physical barrier. This is achieved by influencing multiple processes, including keratinocyte differentiation, stratum corneum formation, and regulation of intercellular contacts. In this review, we summarize the potential contribution of Cutibacterium acnes to these events and outline the contribution of bacterially induced barrier defects to the pathogenesis of acne vulgaris. With the combined effects of a Westernized lifestyle, microbial dysbiosis, epithelial barrier defects, and inflammation, the development of acne is very similar to that of several other multifactorial diseases of barrier organs (e.g., inflammatory bowel disease, celiac disease, asthma, atopic dermatitis, and chronic rhinosinusitis). Therefore, the management of acne requires a complex approach, which should be taken into account when designing novel treatments that address not only the inflammatory and microbial components but also the maintenance and strengthening of the cutaneous physical barrier.

Investigation of possible causes of increase in Hungarian infant mortality in 2019 / A hazai csecsemohalandóságban 2019-ben tapasztalt emelkedés lehetséges okainak vizsgálata.

Összefoglaló. Bevezetés: Magyarországon a csecsemohalandóság 2014 óta folyamatosan javult, azonban 2019-ben az elozo évi adathoz képest 11%-kal magasabb érték mutatkozott. Célkituzés: A vizsgálat célja a 2019. évi kedvezotlenebb csecsemohalálozási mutató lehetséges összetevoinek feltárása. Módszer: A 2018. és 2019. évi csecsemohalálozási adatokat hasonlítottuk össze a csecsemo kora, a halál oka és a gyógyintézeti, illetve nem gyógyintézeti elhalálozás szerint. A vizsgálathoz a Központi Statisztikai Hivatal adatait használtuk. A trendvizsgálatnál 2010-tol elemeztük az adatokat. A nem gyógyintézeti haláleseteket 10 évre összevonva járásonként térképesen ábrázoltuk. Eredmények: 2018-ban 304, 2019-ben 335 csecsemo halt meg Magyarországon, a csecsemohalálozási arányszám 3,4 ezrelékrol 3,8 ezrelékre emelkedett. A 2019. évi érték az elozo évtizedek trendjére illesztett görbe alapján megfelelt a várható értéknek. 2019-ben a 0-27 napos csecsemohalálozás alig változott a 2018. évihez képest, a 28-364 napos korban bekövetkezett halálesetek száma viszont növekedett. A vizsgált évben 59%-kal emelkedett a nem gyógyintézeti csecsemohalálozás. A 2019. évi csecsemohalálozás növekedéséért 74%-ban a nem gyógyintézeti esetek voltak felelosek. A nem gyógyintézeti halálozás dönto többsége késoi csecsemokorban következett be. A járásonkénti, 10 évre összevont, nem intézményben elhunyt csecsemok számában és 1000 élve születésre vonatkozó arányában ötszörös területi különbségek mutatkoztak. A halálokok közül a perinatalis szakban keletkezo bizonyos állapotok miatt meghalt csecsemok száma emelkedett a leginkább, a nem gyógyintézeti halálozás esetében pedig a hirtelen csecsemohalál szindrómában meghaltaké. Következtetés: 2019-ben kiugróan magas volt a nem gyógyintézeti, késoi csecsemohalálozás száma és részaránya, ezen esetek feltuno regionális halmozódást mutattak. A csecsemohalandóság csökkentésének hatásos eszköze lehetne a jövoben minden egyes csecsemohalál részletes szakmai értékelése. Orv Hetil. 2021; 162(1): 830-838. INTRODUCTION: In Hungary, infant mortality has been steadily declining since 2014, but in 2019 it increased by 11% compared to 2018. OBJECTIVE: The aim of our study is to explore the possible components of the above increase. METHOD: Ten-year trends of infant mortality were analized and compared by age, cause, place of deaths (hospital or non-hospital environment) and location, using Central Statistical Office data. RESULTS: There were 304 infant deaths in Hungary in 2018 and 335 in 2019. Infant mortality rate rose from 3.4‰ to 3.8‰, however, it was in line with the expected value based on the curve fitted to the trend of previous decades. In 2019, 0-27-day infant mortality basically did not change compared to 2018, while the number of deaths at 28-364 days of age increased. Non-hospital infant mortality increased by 59% in 2019 and these cases accounted for 74% of the total increase in infant mortality; the vast majority of these deaths occurred in late infancy. There were fivefold regional differences in the number of non-hospital infant deaths. Among the causes of death, the conditions related to the perinatal period and sudden infant death syndrome increased the most. CONCLUSION: In Hungary, the number and proportion of non-hospital infant mortality was remarkably high in 2019 compared to previous years. These cases showed a striking regional accumulation. An effective tool for reducing infant mortality could be an appropriate professional assessment of each infant death in the future. Orv Hetil. 2021; 162(21): 830-838.

Tumour Necrosis Factor Alpha-induced Protein 3 Negatively Regulates Cutibacterium acnes-induced Innate Immune Events in Epidermal Keratinocytes.

Human epidermal keratinocytes sense the presence of human skin microbiota through pathogen recognition receptors, such as toll-like receptors, and induce innate immune and inflammatory events. In healthy epidermis there is an absence of inflammation despite the continuous presence of cutaneous microbes, which is evidence of an effective immune regulatory mechanism. The aim of this study was to investigate tumour necrosis factor alpha-induced protein 3 (TNFAIP3), a negative regulator of toll-like receptor and nuclear factor kappa B signalling pathways, and its role in these regulatory events. A broad spectrum of toll-like receptor ligands induced TNFAIP3 expression, as did live Cutibacterium acnes, which is involved in the pathogenesis of acne. Changes in bacterium-induced, dose-dependent TNFAIP3 expression were Jun kinase- and nuclear factor kappa B-dependent, and resulted in altered cytokine and chemokine levels in in vitro cultured human keratinocytes. In acne lesions, TNFAIP3 mRNA expression was elevated compared with non-lesional skin samples from the same individuals. These results suggest that TNFAIP3 may have a general role in fine regulation of microbiota-induced cutaneous immune homeostasis.

Cutibacterium acnes regulates the epidermal barrier properties of HPV-KER human immortalized keratinocyte cultures.

Our skin provides a physical barrier to separate the internal part of our body from the environment. Maintenance of complex barrier functions is achieved through anatomical structures in the skin, the stratified squamous epithelium specialized junctional organelles, called tight junctions (TJs). Several members of our microbial communities are known to affect the differentiation state and function of the colonized organ. Whether and how interactions between skin cells and cutaneous microbes, including Cutibacterium acnes (C. acnes), modify the structure and/or function of our skin is currently only partly understood. Thus, in our studies, we investigated whether C. acnes may affect the epidermal barrier using in vitro model systems. Real-time cellular analysis showed that depending on the keratinocyte differentiation state, the applied C. acnes strains and their dose, the measured impedance values change, together with the expression of selected TJ proteins. These may reflect barrier alterations, which can be partially restored upon antibiotic-antimycotic treatment. Our findings suggest that C. acnes can actively modify the barrier properties of cultured keratinocytes, possibly through alteration of tight cell-to-cell contacts. Similar events may play important roles in our skin, in the maintenance of cutaneous homeostasis.

TNIP1 Regulates Cutibacterium acnes-Induced Innate Immune Functions in Epidermal Keratinocytes.

Human skin cells recognize the presence of the skin microbiome through pathogen recognition receptors. Epidermal keratinocytes are known to activate toll-like receptors (TLRs) 2 and 4 in response to the commensal Cutibacterium acnes (C. acnes, formerly known as Propionibacterium acnes) bacterium and subsequently to induce innate immune and inflammatory events. These events may lead to the appearance of macroscopic inflammatory acne lesions in puberty: comedos, papules and, pustules. Healthy skin does not exhibit inflammation or skin lesions, even in the continuous presence of the same microbes. As the molecular mechanism for this duality is still unclear, we aimed to identify factors and mechanisms that control the innate immune response to C. acnes in keratinocytes using a human immortalized keratinocyte cell line, HPV-KER, normal human keratinocytes (NHEK) and an organotypic skin model (OSM). TNIP1, a negative regulator of the NF-κB signaling pathway, was found to be expressed in HPV-KER cells, and its expression was rapidly induced in response to C. acnes treatment, which was confirmed in NHEK cells and OSMs. Expression changes were not dependent on the C. acnes strain. However, we found that the extent of expression was dependent on C. acnes dose. Bacterial-induced changes in TNIP1 expression were regulated by signaling pathways involving NF-κB, p38, MAPKK and JNK. Experimental modification of TNIP1 levels affected constitutive and C. acnes-induced NF-κB promoter activities and subsequent inflammatory cytokine and chemokine mRNA and protein levels. These results suggest an important role for this negative regulator in the control of bacterially induced TLR signaling pathways in keratinocytes. We showed that all-trans retinoic acid (ATRA) induced elevated TNIP1 expression in HPV-KER cells and also in OSMs, where TNIP1 levels increased throughout the epidermis. ATRA also reduced constitutive and bacterium-induced levels of TNFα, CCL5 and TLR2, while simultaneously increasing CXCL8 and TLR4 expression. Based on these findings, we propose that ATRA may exhibit dual effects in acne therapy by both affecting the expression of the negative regulator TNIP1 and attenuating TLR2-induced inflammation. Overall, TNIP1, as a possible regulator of C. acnes-induced innate immune and inflammatory events in keratinocytes, may play important roles in the maintenance of epidermal homeostasis.

Propionibacterium acnes Induces Autophagy in Keratinocytes: Involvement of Multiple Mechanisms.

Propionibacterium acnes is a dominant member of the cutaneous microbiota. Herein, we evaluate the effects of different P. acnes strains and propionic acid on autophagy in keratinocytes. Our results showed that P. acnes strain 889 altered the architecture of the mitochondrial network; elevated the levels of microtubule-associated protein 1 light chain 3B-II, Beclin-1, and phospho-5'-adenosine-monophosphate-activated protein kinase α; stimulated autophagic flux; facilitated intracellular redistribution of microtubule-associated protein 1 light chain 3B; increased average number of autophagosomes per cell; and enhanced development of acidic vesicular organelles in the HPV-KER cell line. Propionic acid increased the level of phospho-5'-adenosine-monophosphate-activated protein kinase α, enhanced lipidation of microtubule-associated protein 1 light chain 3B, stimulated autophagic flux, and facilitated translocation of microtubule-associated protein 1 light chain 3B into autophagosomes in HPV-KER cells. P. acnes strains 889 and 6609 and heat-killed strain 889 also stimulated autophagosome formation in primary keratinocytes to varying degrees. These results indicate that cell wall components and secreted propionic acid metabolite of P. acnes evoke mitochondrial damage successively, thereby triggering 5'-adenosine-monophosphate-activated protein kinase-associated activation of autophagy, which in turn facilitates the removal of dysfunctional mitochondria and promotes survival of keratinocytes. Thus, we suggest that low-level colonization of hair follicles with noninvasive P. acnes strains, by triggering a local increase in autophagic activity, might exert a profound effect on several physiological processes responsible for the maintenance of skin tissue homeostasis.