Z. Bata-Csörgö

The anti-apoptotic protein G1P3 is overexpressed in psoriasis and regulated by the non-coding RNA, PRINS

Please cite this paper as: The anti‐apoptotic protein G1P3 is overexpressed in psoriasis and regulated by the non‐coding RNA, PRINS. Experimental Dermatology 2010; 19: 269–278.

CD3+CD56+ NK T cells are significantly decreased in the peripheral blood of patients with psoriasis

Psoriasis is a chronic, inflammatory, hyperproliferative skin disease, in which autoimmunity plays a great role. Natural killer T cells (NK T cells), are suggested to be involved in the pathogenesis of different autoimmune diseases. To examine the involvement of CD3+CD56+ NK T cells in the pathogenesis of psoriasis, we investigated the lymphocyte subpopulations obtained from blood samples of psoriatic patients before and after treatment, and of healthy controls, using two‐colour flow cytometry. We found no significant differences between total T cells, total B cells, T helper cells, T cytotoxic cells and NK cells in patients with psoriasis before and after treatment and in controls. Increased percentage of memory T cells and decreased percentage of naive T cells was detected in psoriatic patients compared to controls, but these changes were not statistically significant. The CD3+CD56+ cells of psoriatic patients were significantly decreased relative to controls. The percentage of CD3+CD56+ cells increased after different antipsoriatic therapies, but remained significantly lower than those found in controls. CD3+CD56+ cells of healthy controls were capable of rapid activation, while in psoriatic patients activated NK T cells were almost absent. The decrease in the number of CD3+CD56+ cells may represent an intrinsic characteristic feature of patients with psoriasis, which is supported by the fact that after treatment NK T cells do not reach the values found in controls. In conclusion our results suggest that CD3+CD56+ NK T cells could be actively involved in the development of Th1 mediated autoimmune diseases.

Serum factors regulate the expression of the proliferation-related genes α5 integrin and keratin 1, but not keratin 10, in HaCaT keratinocytes

Abstract In the highly coordinated programme of gene expression during keratinocyte proliferation and differentiation, ·5 integrin and keratins 1 and 10 (K1/K10) may play important regulatory roles. We were interested in seeing whether, in continuously growing, immortalized HaCaT keratinocytes, similar to normal keratinocytes, the expression of ·5 integrin and K1/K10 was related to cell proliferation and differentiation. After release from cell quiescence the expression of ·5 integrin, both at the mRNA and protein levels, was upregulated in the cells. At the same time, K1/K10 mRNA and protein expression decreased dramatically, while the mRNA for D1 cyclin became detectable, and the cells became highly proliferative. These findings indicate that ·5 integrin and K1/K10 are involved in the regulation of HaCaT proliferation and differentiation, as in normal keratinocytes. However, HaCaT cells are different from normal keratinocytes in their ability to lose K1/K10 expression. There is no evidence that the expression of K1/K10 can be reversed in normal keratinocytes. This ability of dedifferentiation might be a unique feature of HaCaT cells and may be a key component of their immortalized nature. We also found that serum factors regulate mRNA expression of ·5 integrin and K1, but not of K10, in HaCaT cells. This information could be relevant to the understanding of normal epidermal differentiation.

The enigmatic world of mRNA-like ncRNAs: Their role in human evolution and in human diseases

Accumulating data on non-protein-coding transcripts suggest that besides the regulatory machinery driven by proteins, another yet enigmatic regulatory network of RNA molecules operates and has considerable impact on cell functions. Moreover, deregulation of these non-coding RNAs (ncRNAs) has been documented in several human diseases suggesting that they may significantly contribute to their pathogenesis. This review summarizes our present knowledge on the role of the so-called mRNA-like ncRNAs in the complexity of multicellular organisms. We provide some examples to show how these mRNA-like non-coding RNAs have been discovered, how their cellular functions and role in the pathogenesis of human diseases have been revealed.

AP1S3 Mutations Cause Skin Autoinflammation by Disrupting Keratinocyte Autophagy and Up-Regulating IL-36 Production

Prominent skin involvement is a defining characteristic of autoinflammatory disorders caused by abnormal IL-1 signaling. However, the pathways and cell types that drive cutaneous autoinflammatory features remain poorly understood. We sought to address this issue by investigating the pathogenesis of pustular psoriasis, a model of autoinflammatory disorders with predominant cutaneous manifestations. We specifically characterized the impact of mutations affecting AP1S3, a disease gene previously identified by our group and validated here in a newly ascertained patient resource. We first showed that AP1S3 expression is distinctively elevated in keratinocytes. Because AP1S3 encodes a protein implicated in autophagosome formation, we next investigated the effects of gene silencing on this pathway. We found that AP1S3 knockout disrupts keratinocyte autophagy, causing abnormal accumulation of p62, an adaptor protein mediating NF-κB activation. We showed that as a consequence, AP1S3-deficient cells up-regulate IL-1 signaling and overexpress IL-36α, a cytokine that is emerging as an important mediator of skin inflammation. These abnormal immune profiles were recapitulated by pharmacological inhibition of autophagy and verified in patient keratinocytes, where they were reversed by IL-36 blockade. These findings show that keratinocytes play a key role in skin autoinflammation and identify autophagy modulation of IL-36 signaling as a therapeutic target.

Comparison of stress-induced PRINS gene expression in normal human keratinocytes and HaCaT cells

Psoriasis is a chronic inflammatory skin disease that affects approximately 2–4% of the population. We recently described a novel non-coding RNA, psoriasis susceptibility related RNA gene induced by stress (PRINS), that was overexpressed in non-lesional psoriatic epidermis, and its expression was induced by various stress factors such as serum starvation, contact inhibition, ultraviolet (UV)-B irradiation, viral infection and translational inhibition in HaCaT cells. In the present work we set out to compare the stress and microbial agent-induced PRINS expression in normal human keratinocytes (NHKs) and HaCaT cells. Since nuclear factor-κB (NF-κB) is involved in the cellular stress response, we sought to explore whether there is a connection between the NF-κB and PRINS-mediated signal transduction pathways in NHKs and HaCaT cells. We found that the PRINS expression responded differentially to various stress signals and microbial agents in HaCaT cells and in NHKs: after translational inhibition and UV-B treatment, similar induction of PRINS expression occurred with different time courses while after microbial agent treatment, the PRINS expression was significantly induced in HaCaT cells, whereas we could not detect similar changes in NHKs. To explore whether the known NF-κB abnormalities in HaCaT cells could be related to this differential PRINS expression, we silenced the PRINS gene expression with small interfering RNA (siRNA) in both HaCaT cells and in NHKs and monitored NF-κB signal transduction after lipopolysaccharide (LPS) treatment. Silencing of PRINS had no effect on LPS-induced NF-κB activity either in HaCaT cells or in NHKs. Our results indicate that PRINS probably affects keratinocytes functions independently of NF-κB signalling.

The Arg160Trp allele of melanocortin-1 receptor gene might protect against vitiligo.

Melanocortin‐1 receptor (MC1R) and agouti signaling protein (ASIP) play pivotal roles in the regulation of human pigmentation. We aimed to study whether single nucleotide polymorphisms (SNPs) of the MC1R and ASIP genes contribute to the pathogenesis of the polygenic pigment skin disorder, vitiligo. The PCR‐amplified, full‐length MC1R gene was studied with sequence analysis, and the 3′ untranslated region (3′ UTR) SNP of ASIP was detected using restriction fragment length polymorphism. The allele frequency of the ASIP SNP did not show any difference between the skin type, hair color and eye color‐matched 97 vitiligo patients and the 59 healthy control individuals. As one of the MC1R polymorphisms showed significantly higher incidence among fair‐skinned individuals (Fitzpatrick I + II, n = 140) than among dark‐skinned individuals (Fitzpatrick III + IV, n = 90), both vitiligo patients and controls were divided into two groups and the frequency of the MC1R alleles was studied separately in fair‐skinned and dark‐skinned subgroups of diseased and healthy groups. C478T, one of the MC1R SNPs studied in 108 fair‐skinned vitiligo patients and in 70 fair‐skinned healthy control individuals, showed a significant difference (P = 0.0262, odds ratio [95% confidence interval] = 3.6 [0.0046–0.1003]) in allele frequency between the two groups: the allele frequency was higher in the control group, suggesting protection against vitiligo. Computer prediction of antigenicity has revealed that the Arg160Trp amino acid change caused by this SNP results in a decrease in antigenicity of the affected peptide epitope.

TLR2 and TLR4 polymorphisms are not associated with acne vulgaris

crobial molecular patterns. Since TLR2 and TLR4 affect immune processes, they may play a role in the pathogenesis of acne. TLR2 and TLR4 expression was found to be increased in the epidermis of acne lesions in vivo [9] ; furthermore, TLR2 was expressed on the cell surface of macrophages surrounding pilosebaceous follicles, and P. acnes induced the cytokine production of monocytes through a TLR2-dependent pathway [10] . Here we have investigated two mutations of the TLR2 gene (C2179T in the NM_003264.2 sequence and rs5743708 causing the amino acid changes Arg677Trp and Arg753Gln, respectively) as well as two polymorphisms of the TLR4 gene (rs4986790 and rs4986791 causing the amino acid changes Asp299Gly and Thr399Ile, respectively) in 101 Caucasian subjects, 63 with acne vulgaris and 38 healthy controls. These polymorphisms have been suggested to be associated with several infectious diseases [11] . Acne vulgaris diagnosis was defined as a physician’s diagnosis. Acne patients were subclassified into three groups, as having severe symptoms (acne conglobata group, n = 17), medium symptoms (acne papulopustulosa group, n = 39) and mild symptoms (acne comedonica group, n = 7). The control group comprised patients showing no symptoms of acne during their life. We isolated genomic DNA from whole blood obtained from the study subjects, using the Perfect gDNA Blood Mini Isolation Kit (Eppendorf AG, Hamburg, Germany)

The expression of keratinocyte growth factor receptor (FGFR2-IIIb) correlates with the high proliferative rate of HaCaT keratinocytes

Abstract:  Keratinocyte growth factor receptor (KGFR = FGFR2‐IIIb) is a tyrosine kinase receptor expressed by keratinocytes, which mediates the effects of fibroblast growth factors (FGF). There are contradictory data in the literature regarding the role of FGFR2‐IIIb during the proliferation/differentiation programme of keratinocytes. In this study, we aimed to investigate whether overexpression of FGFR2‐IIIb may have a role in the regulation of keratinocyte proliferation. We analysed the expression of FGFR2‐IIIb in an in vitro HaCaT model system representing different stages of proliferation and differentiation of keratinocytes. Real‐time RT‐PCR and Western blot analyses demonstrated a correlation between FGFR2‐IIIb mRNA and protein expression and the proportion of cells in S/G2/M phase in synchronized HaCaT keratinocytes and thus with proliferation activity (r = 0.96). After treatment with the antipsoriatic drug, dithranol, FGFR2‐IIIb is downregulated dose dependently both at mRNA and protein levels. Moreover, when the rate of proliferation is decreased by the lack of cell attachment to the culturing surface, FGFR2‐IIIb mRNA (P = 0.0315) and protein expressions were also reduced (P = 0.0242), while a differentiation marker, keratin 10, mRNA (P = 0.0003) and protein levels (P = 0.001) were increased (r = −0.92). Based on our results we conclude that FGFR2‐IIIb expression in HaCaT keratinocytes corresponds with the proliferative activation of the cells and is not related to the differentiation programme.

Strontium ranelate-induced DRESS syndrome with persistent autoimmune hepatitis

A relatively new drug used in the treatment of osteoporosis, strontium ranelate has been associated with several side effects, including increased relative risk of venous thromboembolism (including pulmonary embolism), transient increases in creatine kinase levels, mild gastrointestinal, nervous system and muscular disorders, and drug-induced hypersensitivity syndrome, also called DRESS syndrome (1). DRESS syndrome is a severe, acute drug reaction defined by the presence of fever, skin eruptions and systemic symptoms, including enlarged lymph nodes, abnormal liver function, renal impairment, and pulmonary and cardiac infiltrates, as well as haematological abnormalities, primarily hypereosinophilia and lymphocytosis (2, 3). We report here a case of a patient with strontium ranelate-induced DRESS who developed persistent autoimmune hepatitis.