POS0135 DOWNREGULATION OF miR-885-5p AS A KEY EFFECTOR IN CUTANEOUS LUPUS ERYTHEMATOSUS PATHOGENESIS

Background

Skin involvement is common in systemic lupus erythematosus (SLE), with up to 70% of patients developing skin lesions at some point during the course of their disease. Moreover, cutaneous lesions are the first sign of systemic disease in 20% of SLE patients [1]. Skin requires a regulated and undisrupted miRNA profile for a correct development and function. Studies show that miRNAs play a pathogenic role in autoimmune skin diseases such as Psoriasis [2]. Understanding of the role of deregulated miRNAs in CLE may enhance our knowledge about CLE pathogenesis which is currently not understood.

Objectives

Identify differentially expressed miRNAs in skin lesions to determine their role in CLE pathogenesis.

Methods

Paired skin biopsies from CLE lesional (n=20) and non-lesional skin (n=20) were obtained. MiRNA microarray screening was performed using TaqMan MicroRNA Array. Validation was performed in a new cohort of FFPE skin samples by qRT-PCR (n=20). In situ hybridization was performed to identify the skin cell type involved in selected miRNAs. Next, in vitro experiments using primary skin and immune cells were performed in order to discover their role in CLE pathogenesis. A microarray screening and luciferase assay were performed to find miR-885-5p altered gene expression, molecular pathways and target genes.

Results

MiR-885-5p was found downregulated in CLE lesional skin (-4.45 fold, pvalue<0,01, respectively). Results were confirmed in a validation cohort. In situ hybridization revealed miR-885-5p was located in the epidermal keratinocytes in CLE non-lesional skin. Healthy keratinocytes presented an increased miR-885-5p expression compared with other relevant cell types such as fibroblasts (p<0.001) or PBMCs (p<0.001). Moreover stimulation with IFNα and UVB promoted a marked long-lasting downregulation of miR-885-5p (IFNα, 24h -67 fold (p<0.001); UVB, 24h -70 fold (p<0.001)).

Gene microarray of anti-miR-885-5p keratinocytes showed that the unique gene that was upregulated in all anti-miR-885-5p conditions was PSMB5. In vitro experiments demonstrated that PSMB5 is a direct target of miR-885-5p (74% of reduction p<0.001) and it is involved in epidermal inflammation by enhancing NFKB and inflammatory cytokines IL-1β, TNFα and CXCL8. In addition, we observed immune recruitment in UVB stimulated anti-miR885-5p keratinocytes and we found that this immune migration is mediated via miR-885-5p direct binding of TRAF1 and subsequent chemokine CCL5, CCL20, CXCL8 and S100A7 secretion.

Conclusion

Our findings demonstrate that CLE lesions present a downregulation of miR-885-5p that is strongly implicated in CLE pathogenesis. Moreover, miRNA applicability as therapeutics makes the discovered miRNAs promising candidates for novel therapy in CLE, as there is a need to develop new therapies for refractory cases and to avoid current treatment significant side effects.

References

[1]Okon LG, Werth VP. Cutaneous lupus erythematosus: diagnosis and treatment. Best Pract Res Clin Rheumatol. 2013; 27(3):391-404.

[2]Sonkoly E et al. MicroRNAs: novel regulators involved in the pathogenesis of psoriasis? PLoS One. 2007. 11;2(7):e610.

Disclosure of Interests

None declared

ALDH1A3 is epigenetically regulated during melanocyte transformation and is a target for melanoma treatment

Despite the promising targeted and immune-based interventions in melanoma treatment, long-lasting responses are limited. Melanoma cells present an aberrant redox state that leads to the production of toxic aldehydes that must be converted into less reactive molecules. Targeting the detoxification machinery constitutes a novel therapeutic avenue for melanoma. Here, using 56 cell lines representing nine different tumor types, we demonstrate that melanoma cells exhibit a strong correlation between reactive oxygen species amounts and aldehyde dehydrogenase 1 (ALDH1) activity. We found that ALDH1A3 is upregulated by epigenetic mechanisms in melanoma cells compared with normal melanocytes. Furthermore, it is highly expressed in a large percentage of human nevi and melanomas during melanocyte transformation, which is consistent with the data from the TCGA, CCLE and protein atlas databases. Melanoma treatment with the novel irreversible isoform-specific ALDH1 inhibitor [4-dimethylamino-4-methyl-pent-2-ynthioic acid-S methylester] di-methyl-ampal-thio-ester (DIMATE) or depletion of ALDH1A1 and/or ALDH1A3, promoted the accumulation of apoptogenic aldehydes leading to apoptosis and tumor growth inhibition in immunocompetent, immunosuppressed and patient-derived xenograft mouse models. Interestingly, DIMATE also targeted the slow cycling label-retaining tumor cell population containing the tumorigenic and chemoresistant cells. Our findings suggest that aldehyde detoxification is relevant metabolic mechanism in melanoma cells, which can be used as a novel approach for melanoma treatment.

Microarray study reveals a transforming growth factor-β-dependent mechanism of fibrosis in discoid lupus erythematosus

BACKGROUND

Discoid lupus erythematosus (DLE) is characterized by scarring lesions that develop and perpetuate fibrotic lesions. These are not observed in subacute cutaneous lupus erythematosus (SCLE). The pathophysiological basis of this is currently unknown.

OBJECTIVES

To identify contradistinctive signalling pathways and cellular signatures between the two type of lupus, with a focus on the molecular mechanisms leading to fibrosis.

METHODS

We conducted a gene expression microarray analysis in lesional and nonlesional skin biopsy specimens of patients with DLE (n = 10) and SCLE (n = 10). Confirmatory reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry were performed on selected transcripts in a new cohort of paraffin-embedded skin biopsies (n = 20). Changes over time of a group of selected inflammatory and fibrotic genes were also evaluated in a second biopsy taken 12 weeks later. In vitro functional studies were performed in primary isolated fibroblasts.

RESULTS

Compared with nonlesional skin, DLE samples expressed a distinctive T-cell gene signature. DLE samples displayed a significant CD4 T-cell enrichment with an imbalance towards T helper 1 cytokine predominance and a relative increased forkhead box (FOX)P3 response. RT-qPCR and immunochemical analysis over time showed a progressive increment of fibrotic markers and persistent FOXP3 recruitment. Ex vivo upregulation of SERPINE1, MMP9, TGFBR1, phosphorylated SMAD3 and TGFB1 suggested a transforming growth factor (TGF)-β-dependent mechanism of fibrosis in DLE, also confirmed by the results observed following in vitro stimulation with TGF-β.

CONCLUSIONS

These results highlight major pathogenic pathways in DLE and provide novel molecular targets for the development of new therapies. The data suggest the existence of a TGF-β-dependent pathway inducing fibrosis in DLE.

Interleukin-6 deletion in mice driven by aP2-Cre-ERT2 prevents against high-fat diet-induced gain weight and adiposity in female mice

AIM

Interleukin-6 (IL-6) is a major cytokine controlling body weight and metabolism, but because many types of cells can synthesize and respond to IL-6 considerable uncertainty still exists about the mechanisms underlying IL-6 effects. Therefore, the aim of this study was to analyse the effects of tissue-specific deletion of IL-6 using a fatty acid binding protein (aP2) promoter-Cre inducible system (aP2-Cre-ERT2).

METHODS

Tissue-specific IL-6 KO mice (aP2-IL-6 KO mice) were produced upon tamoxifen administration and were fed a high-fat diet (HFD, 58.4% kcal from fat) or a control diet (18%) for 14 weeks.

RESULTS

aP2-IL-6 KO female mice on a HFD gained less weight and adiposity than littermate wild-type mice, but these effects were not observed in males. Hypothalamic factors such as NPY and AgRP showed a pattern of expression consistent with this sex-specific phenotype. PGC-1α expression was increased in several tissues in aP2-IL-6 KO female mice, which is compatible with increased energy expenditure. Serum leptin, insulin, glucose, cholesterol and triglycerides levels were increased by HFD, and in females IL-6 deficiency reversed this effect in the case of insulin and cholesterol. HFD induced impaired responses to insulin and glucose tolerance tests, but no significant differences between genotypes were observed.

CONCLUSION

The present results demonstrate that deletion of IL-6 driven by aP2-Cre regulates body weight, body fat and metabolism in a sex-specific fashion.

Interleukin-6 regulates the expression of hypothalamic neuropeptides involved in body weight in a gender-dependent way

Interleukin (IL)-6 has been involved in the control of body weight and body fat. Nevertheless, the mechanisms underlying these effects are not completely understood because central and peripheral actions of IL-6 are plausible. To gain further insight into the central effects of IL-6, we used transgenic mice expressing the IL-6 gene under the control of the glial fibrillary acidic protein (GFAP) promoter (GFAP-IL-6 mice), therefore with central nervous system-restricted over-expression of IL-6, and we studied the expression of the main neuropeptides responsible for energy homeostasis in specific hypothalamic nuclei. Neuropeptide Y (NPY), agouti-related peptide (AgRP), melanin-concentrating hormone (MCH), prepro-orexin (preproOX) (orexigenic and anabolic neuropeptides), pro-opiomelanocortin (POMC) and corticotrophin-releasing hormone (CRH) (anorexigenic and catabolic peptides) mRNA levels were determined using in situ hybridisation in young (2-4 month-old) and old (10-12 month-old) female and male mice under different feeding conditions: normal diet (control) and high-fat diet (HFD), and 24 h-food deprivation. In GFAP-IL-6 females fed a control diet (GFAP-IL-6-control), we showed a significant decrease in NPY and AgRP mRNA levels at all ages, and a late increase in POMC expression (only significant in older animals). These differences were blunted in HFD mice. By contrast, GFAP-IL-6-control males showed a decrease in CRH mRNA content at early ages (2-4 months), and an increase in older mice (10-12 months). Interestingly, these differences were again blunted in HFD mice. Finally, central IL-6 was not able to counteract the effects of 24 h of fasting on body weight, plasma glucose levels and the mRNA content of the peptides evaluated in the present study. Our results demonstrate that IL-6 may regulate the expression of hypothalamic neuropeptides involved in the control of body weight and body fat acting at the central level in a gender- and age-dependent way.

Efficacy of silver diamine fluoride for caries reduction in primary teeth and first permanent molars of schoolchildren: 36-month clinical trial

We hypothesized that the six-monthly application of silver diamine fluoride (SDF) can arrest the development of caries in the deciduous dentition of six-year-old schoolchildren and prevent caries in their first permanent molars. A prospective controlled clinical trial was conducted on the efficacy of a 38% SDF solution for caries reduction. Four hundred and twenty-five six-year-old children were divided into two groups: One group received SDF solution in primary canines and molars and first permanent molars every 6 mos for 36 mos. The second group served as controls. The 36-month follow-up was completed by 373 children. The mean number of new decayed surfaces appearing in primary teeth during the study was 0.29 in the SDF group vs. 1.43 in controls. The mean of new decayed surfaces in first permanent molars was 0.37 in the SDF group vs. 1.06 in controls. The SDF solution was found to be effective for caries reduction in primary teeth and first permanent molars in schoolchildren.

Activation of nuclear factor-kappa B is linked to resistance to neoadjuvant chemotherapy in breast cancer patients

The nuclear factor (NF)-kappaB system is a promising anticancer target due to its role in oncogenesis and chemoresistance in preclinical models. To provide evidence in a clinical setting on the role of NF-kappaB in breast cancer, we aimed to study the value of basal NF-kappaB/p65 in predicting resistance to neoadjuvant chemotherapy, and to characterise the pharmacodynamic changes in NF-kappaB/p65 expression following chemotherapy in patients with locally advanced breast cancer. Pre- and post-chemotherapy tumour specimens from 51 breast cancer patients treated with anthracycline- and/or taxane-containing neoadjuvant chemotherapy were assayed by immunohistochemistry for NF-kappaB/p65 subcellular expression. We studied NF-kappaB/p65, a well-characterised member of the NF-kappaB family that undergoes nuclear translocation when NF-kappaB is activated. Activation of NF-kappaB (i.e. nuclear NF-kappaB/p65 staining in pre-therapy specimens) was linked to chemoresistance. Patients with NF-kappaB/p65 nuclear staining in pre-treatment samples had a 20% clinical response rate, while patients with undetected nuclear staining had a 91% response rate to chemotherapy (P = 0.002). Notably, four patients achieved a complete histological response and none of them had pre-treatment NF-kappaB/p65 nuclear staining. Moreover, the number of patients with NF-kappaB/p65 activation increased after chemotherapy exposure. It is concluded that NF-kappaB/p65 activation assayed by immunohistochemistry is a predictive factor of resistance to neoadjuvant chemotherapy in breast cancer patients. Moreover, NF-kappaB activation was inducible following chemotherapy in a proportion of breast cancer patients. These novel clinical findings strengthen the rationale for the use of NF-kappaB inhibitors to prevent or overcome chemoresistance in breast cancer.

Activation of nuclear factor-kappaB in human prostate carcinogenesis and association to biochemical relapse

Nuclear factor (NF)-κB/p65 regulates the transcription of a wide variety of genes involved in cell survival, invasion and metastasis. We characterised by immunohistochemistry the expression of NF-κB/p65 protein in six histologically normal prostate, 13 high-grade prostatic intraepithelial neoplasia (PIN) and 86 prostate adenocarcinoma specimens. Nuclear localisation of p65 was used as a measure of NF-κB active state. Nuclear localisation of NF-κB was only seen in scattered basal cells in normal prostate glands. Prostatic intraepithelial neoplasias exhibited diffuse and strong cytoplasmic staining but no nuclear staining. In prostate adenocarcinomas, cytoplasmic NF-κB was detected in 57 (66.3%) specimens, and nuclear NF-κB (activated) in 47 (54.7%). Nuclear and cytoplasmic NF-κB staining was not correlated (P=0.19). By univariate analysis, nuclear localisation of NF-κB was associated with biochemical relapse (P=0.0009; log-rank test) while cytoplasmic expression did not. On multivariate analysis, serum preoperative prostate specific antigen (P=0.02), Gleason score (P=0.03) and nuclear NF-κB (P=0.002) were independent predictors of biochemical relapse. These results provide novel evidence for NF-κB/p65 nuclear translocation in the transition from PIN to prostate cancer. Our findings also indicate that nuclear localisation of NF-κB is an independent prognostic factor of biochemical relapse in prostate cancer.

Sudden death in Staphylococcus aureus-associated infective endocarditis due to perforation of a free-wall myocardial abscess

Free-wall myocardial abscess perforation with hemopericardium and sudden death is an extremely infrequent complication of infective endocarditis (IE). We describe a case of Staphylococcus aureus-associated native aortic and tricuspid valve endocarditis complicated by a septic myocardial infarction and abscess formation of embolic origin, with fatal rupture into the pericardium. To our knowledge, only 2 cases of myocardial abscess rupture have previously been reported in relation to IE.

First molecular switch encapsulated within the cavities of a zeolite. A dramatic lifetime increase of the charge-separated state

A [2]-catenane consisting of a bipyridinium cyclophane and a dioxybenzene macrocyclic polyether has been encapsulated within the supercages of zeolite Y by ship-in-a-bottle synthesis; laser flash photolysis reveals that the charge-separated species decays in hundreds of microseconds in contrast to the few picoseconds previously reported for the same transient in acetonitrile.

Placental malaria is associated with cell-mediated inflammatory responses with selective absence of natural killer cells

Immunosuppression, particularly of cell-mediated responses, has classically been thought to play a major role in the increased susceptibility to malaria observed in pregnant women. An immunohistochemical characterization of the inflammatory infiltrate in a group of 41 placentas from women living in a Plasmodium falciparum-hyperendemic area in Tanzania revealed a marked increase in the number of monocytes and macrophages and cytotoxic T cells in the intervillous space of placentas with active malaria infection, compared with noninfected placentas, placentas from women with past infection, and a control group of placentas from Spain. This increase was associated with the severity of the infection. High numbers of monocytes and macrophages were associated with low birth weight. We also detected a complete absence of NK cells in the intervillous space in all placentas. This apparently physiological absence of NK cells may contribute to hindering the clearance of the parasite. These results indicate that placental malaria does not appear to be associated with cell-mediated immunosuppression. The role of the absence of NK cells in increased susceptibility to malaria needs to be further elucidated.

[Social development and family composition (author's transl)]

Starting from the theory regarding the social behaviour of the child and, on the other hand, from the concept of the family as a cultural and psychological and, in addition, sociological unit, an index of social development for children of 6 to 14 years of age is presented, and which is obtained by adding the process of school adaptation plus the process of learning plus personal attitudes. Having this hypothesis as a working basis, a study has been carried out on a total of 240 pupils (120 males and 120 girls) included in the chronological age of from 6 to 14 and belonging to National Schools in Zaragoza (Spain) and within the on going program of growth and development. Social development has been studied through inquiries of personal application at family level and through the application of psychograms of our own tabulation. The number of children in the family has been related to the aforementioned parameters, five family units having been established: one child, two children, three children, four children, five or more children. The overall result indicates that the index of social development proposed by us is higher in the case of unique children; that it is practically the same for those children whose family unit is of two, three or four children, and is sensibly lesser in children included in the family unit of five or more children.