Identification of putative genetic modifying factors that influence the development of Papillon-Lefévre or Haim-Munk syndrome phenotypes

BACKGROUND

Papillon-Lefévre syndrome (PLS; OMIM 245000) and Haim-Munk syndrome (HMS; OMIM 245010), which are both characterized by palmoplantar hyperkeratosis and periodontitis, are phenotypic variants of the same disease caused by mutations of the cathepsin C (CTSC) gene.

AIM

To identify putative genetic modifying factors responsible for the differential development of the PLS or HMS phenotypes, we investigated two Hungarian patients with different phenotypic variants (PLS and HMS) but carrying the same homozygous nonsense CTSC mutation (c.748C/T; p.Arg250X).

METHODS

To gain insights into phenotype-modifying associations, whole exome sequencing (WES) was performed for both patients, and the results were compared to identify potentially relevant genetic modifying factors.

RESULTS

WES revealed two putative phenotype-modifying variants: (i) a missense mutation (rs34608771) of the SH2 domain containing 4A (SH2D4A) gene encoding an adaptor protein involved in intracellular signalling of cystatin F, a known inhibitor of the cathepsin protein, and (ii) a missense variant (rs55695858) of the odorant binding protein 2A (OBP2A) gene, influencing the function of the cathepsin protein through the glycosyltransferase 6 domain containing 1 (GLT6D1) protein.

CONCLUSION

Our study contributes to the accumulating evidence supporting the clinical importance of phenotype-modifying genetic factors, which have high potential to aid the elucidation of genotype-phenotype correlations and disease prognosis.

The management and genetic background of pityriasis rubra pilaris: a single-centre experience

BACKGROUND

Pityriasis rubra pilaris (PRP) is a rare chronic inflammatory dermatosis with multifactorial aetiology. It is known that particular caspase recruitment domain family member 14 (CARD14) gene mutations are associated with familial PRP and certain forms of psoriasis. Additionally, few data are available about the role of CARD14 gene variants in sporadic PRP. The clinical picture is variable for the different types of PRP, therefore choosing the adequate treatment is often difficult, furthermore there are no specific guidelines for therapy.

OBJECTIVE

Our aim was to survey the efficacy of the applied therapies and to screen the CARD14 gene variants in our PRP patients.

METHODS

In this retrospective study, patients diagnosed with PRP between 2006 and 2016 at our clinic were involved. Besides the follow-up study of the treatments, the genetic analysis of CARD14 gene was performed.

RESULTS

We analysed 19 patients, among whom 17 were diagnosed with type I, one with type III, and one with type V PRP. The majority of the patients were successfully treated with acitretin in combination with systemic corticosteroids, and the remaining patients were treated with other systemic therapies with diverse effects. The genetic screening of CARD14 gene revealed two previously described mutations (rs114688446, rs117918077) and six polymorphisms (rs28674001, rs2066964, rs34367357, rs11653893, rs11652075, rs2289541). Ten of 19 patients carried different CARD14 genetic variants either alone or in combination.

CONCLUSION

Based on our experience, we propose that acitretin and an initial combination of short-term systemic corticosteroid therapy could be a successful treatment option for PRP. Although we identified several CARD14 variants in almost half of our cases, we did not find a correlation between the therapeutic response and the genetic background. Our data support the previous observation that CARD14 genetic variants are not specific to PRP, although they may indicate chronic inflammation.

Atypical neurofibromatosis type 1 with unilateral limb hypertrophy mimicking overgrowth syndrome

Neurofibromatosis type 1 (NF1; OMIM 162200), a dominantly inherited multitumor syndrome, results from mutations in the Neurofibromin 1 (NF1) gene. We present the case of a Hungarian woman with the clinical phenotype of NF1 over her whole body and the clinical features of unilateral overgrowth involving her entire left leg. This unusual phenotype suggested either the atypical form of NF1 or the coexistence of NF1 and overgrowth syndrome. Direct sequencing of the genomic DNA isolated from peripheral blood revealed a novel frameshift mutation (c.5727insT, p.V1909fsX1912) in the NF1 gene. Next-generation sequencing of 50 oncogenes and tumour suppressor genes, performed on the genomic DNAs isolated from tissue samples and peripheral blood, detected only wild-type sequences. Based on these results, we concluded that the patient is affected by an unusual phenotype of NF1, and that the observed unilateral overgrowth of the left leg might be a rare consequence of the identified c.5727insT mutation.

Abnormal regulation of fibronectin production by fibroblasts in psoriasis

BACKGROUND

Data indicate that in psoriasis, abnormalities are already present in nonlesional skin. Transforming growth factor-β and keratinocyte growth factor (KGF), together with fibronectin and α5β1 integrin, were suggested to play a crucial role in the pathogenesis of psoriasis by influencing inflammation and keratinocyte hyperproliferation.

OBJECTIVES

To investigate the expression of KGF, fibroblast growth factor receptor (FGFR)2, fibronectin (FN) and extra domain A (EDA)-positive FN in healthy and nonlesional psoriatic skin, and to study the effect of KGF on the regulation of FN and EDA(+) FN production by fibroblasts.

METHODS

Healthy, nonlesional psoriatic skin and lesional psoriatic skin were immunostained for α5 integrin, KGF, FGFR2, EDA(+) FN and signal transducer and activator of transcription (STAT)1. KGF-treated cell cultures were analysed for FN and EDA(+) FN mRNA and protein by real-time reverse-transcriptase polymerase chain reaction and flow cytometry, respectively. The major downstream signalling of KGF was investigated by blocking experiments using inhibitors of mitogen-activated protein kinase (MAPK) kinase (MEK1), AKT1/2, STAT1 and STAT3.

RESULTS

The expression of α5 integrin, EDA(+) FN, KGF and its receptor FGFR2 is elevated in psoriatic nonlesional skin compared with healthy skin. KGF mildly induced EDA(+) FN, but not FN expression in healthy fibroblasts through MAPK signalling. Fibroblasts express the FGFR2-IIIc splice variant. STAT1 negatively regulates both FN and EDA(+) FN expression in healthy fibroblasts, and this regulation is compromised in fibroblasts derived from nonlesional psoriatic dermis. We detected active STAT1 in healthy and lesional skin, similarly to a previous report. However, in the nonlesional skin STAT1 activation was absent in tissues far away from lesions.

CONCLUSIONS

The production of FN and EDA(+) FN by fibroblasts and the signalling of STAT1 are abnormally regulated in psoriatic nonlesional skin.

UVB-dependent changes in the expression of fast-responding early genes is modulated by huCOP1 in keratinocytes

Ultraviolet (UV) B is the most prominent physical carcinogen in the environment leading to the development of various skin cancers. We have previously demonstrated that the human ortholog of the Arabidopsis thaliana constitutive photomorphogenesis 1 (COP1) protein, huCOP1, is expressed in keratinocytes in a UVB-regulated manner and is a negative regulator of p53 as a posttranslational modifier. However, it was not known whether huCOP1 plays a role in mediating the UVB-induced early transcriptional responses of human keratinocytes. In this study, we report that stable siRNA-mediated silencing of huCOP1 affects the UVB response of several genes within 2 h of irradiation, indicating that altered huCOP1 expression sensitizes the cells toward UVB. Pathway analysis identified a molecular network in which 13 of the 30 examined UVB-regulated genes were organized around three central proteins. Since the expression of the investigated genes was upregulated by UVB in the siCOP1 cell line, we hypothesize that huCOP1 is a repressor of the identified pathway. Several members of the network have been implicated previously in the pathogenesis of non-melanoma skin cancers; therefore, clarifying the role of huCOP1 in these skin diseases may have clinical relevance in the future.

Thrombosis and risk factors in female patients with a rare acquired thrombophilia: chronic myeloproliferative disorder - polycythaemia vera and essential thrombocythaemia

OBJECTIVE

In polycythaemia vera (PV) and essential thrombocythaemia (ET), the life expectancy of the patients is greatly affected by thrombotic events. An investigation was performed of the potential association of PV/ET, and thrombotic complications with cardiovascular (CV) risk factors, a leukocyte count at the haematological diagnosis > 11.1 G/L, and the JAK2V617F mutation.

PATIENTS AND METHODS

In the period 1998-2011, 128 women with a median age of 62 years were enrolled.

RESULTS

The risk of thrombotic events before the diagnosis was 32.8% (42/128), while in the follow-up period it was 10.2% (13/128). The difference in the probability of thrombosis-free survival between those with at most one CV risk factor and those with two or more CV risk factors was significant (p = 0.005). The presence of two or more CV risk factors (univariate: p = 0.011; multivariate: relative risk: 4.728, 95% CI 1.312-17.040; p = 0.018) significantly increased the risk of thrombosis. Univariate analyses revealed that high blood pressure (p = 0.001), hyperlipidaemia (p = 0.005) and cigarette smoking (p = 0.051) were associated with a significantly higher risk of thrombosis. Analyses of the influence of the leukocyte count (univariate: p = 0.424; multivariate: relative risk: 1.407, 95% CI 0.359-5.507; p = 0.624) and the JAK2V617F mutation (univariate: p = 0.367; multivariate: relative risk: 1.428, 95% CI 0.316-6.460; p = 0.643) on subsequent thrombotic complications resulted in a non-signicant tendency.

CONCLUSIONS

Female patients who display CV risk factors (high blood pressure, hyperlipidaemia and/or cigarette smoking) and PV or ET may well be at a higher risk of thrombotic events and require special consideration as concerns as the prevention and management of thrombotic events.

Detection of a rare CDKN2A intronic mutation in a Hungarian melanoma-prone family and its role in splicing regulation

BACKGROUND

The major locus for melanoma predisposition is the cell cycle regulatory CDKN2A gene on chromosome 9p21. However, the frequency of germline coding mutations of the CDKN2A gene is lower than expected in melanoma-prone families linked to chromosome 9p21.

OBJECTIVES

To investigate whether the rare IVS1+37 G/C intronic mutation of the CDKN2A gene, recently identified in a Hungarian melanoma-prone family, influences mRNA splicing regulation.

METHODS

CDKN2A minigenes containing the wild-type and the mutant intronic sequence were created and transfected into HeLa cells with the aim of studying the mRNA transcripts.

RESULTS

The results revealed the emergence of a differential splicing pattern from the wild-type and the mutant minigene, suggesting that this mutation may alter the splicing of CDKN2A primary mRNA and therefore might have a pathogenetic role in familial melanoma.

CONCLUSIONS

We believe that these results confirm the importance of the identification and characterization of CDKN2A intronic mutations with a view to improving our understanding of the pathogenesis, and explain why the frequency of germline coding mutations of the CDKN2A gene is lower than expected in melanoma-prone families linked to chromosome 9p21.

Interleukin-1A +4845(G> T) polymorphism is a factor predisposing to acne vulgaris

Acne vulgaris is a common chronic inflammatory skin disease of multifactorial origin. The aim of this study was to clarify whether known polymorphisms of the interleukin-1A (IL1A) and IL1RN genes play a role in the pathogenesis of acne vulgaris. A positive association was found between the minor T allele of the IL1A +4845(G>T) single nucleotide polymorphism (SNP) and acne, whereas no association was found with respect to any alleles of the variable number of tandem repeats (VNTR) polymorphism of the IL1RN gene. The severity of inflammatory acne symptoms correlated with the percentage of individuals carrying the homozygote T/T genotype. These results may help to elucidate the molecular events leading to the development of acne.

Simultaneous adeno- and squamous cell carcinoma with different phenotypic profiles in a rat model of chronic gastroesophageal reflux

The aim of our study was to investigate the incidence of duodeno-gastroesophageal reflux-induced malignant transformation in a series of duodeno-esophageal anastomosis operations in rats. This surgical method provides a model for reflux-induced esophageal pathologies, without carcinogen administration. The study design included the follow-up of 31 cases. Thirty weeks of duodeno-gastroesophageal reflux disease significantly increased the risk of the development of Barrett's esophagus, and reflux-induced esophageal adenocarcinoma formation was evident in four animals. In one of these particular cases, a superficial squamous cell cancer was noted in close vicinity to the adenocarcinoma formation. For further analysis, a detailed immunohistochemical staining protocol was used. The immunophenotypes revealed cyclin D1 expression (nuclear positivity in 35% of all the squamous cells), p53 protein accumulation (50% nuclear positivity), with a low expression of cox-2, and negative c-erbB2 staining in the squamous carcinoma cells. The specialized intestinal metaplasia and mucinous adenocarcinoma cells exhibited exclusively diffuse cox-2 positivity (90% of all glandular cells) and weak focal c-erbB2 (5%) staining, without cyclin D1 expression or p53 protein accumulation. Real-time polymerase chain reaction was applied to quantify the abundance of p53, cyclin D1 and cox-2 mRNAs in this biopsy. The most dramatic changes were observed in the level of expression of cyclin D1 (a 9.08-fold expression as compared with the non-treated esophagus samples), while the p53 and cox-2 gene expressions were increased by 1.61 and 2.45-fold, respectively, relative to the non-treated samples. The results afford evidence of the simultaneous activation of more than one possible carcinogenetic pathway in experimental gastroesophageal reflux disease. Synchronous neoplasm formation with different growth pattern characteristics is a rarity in humans, and this phenomenon suggests that the presented model is a suitable means of mimicking the whole spectrum of human gastroesophageal reflux disease pathology.

Moxifloxacin versus Standard Therapy in Patients with Pneumonia Hospitalized after Failure of Preclinical Anti-infective Treatment

The failure rate of primary empirical anti-infective treatment of community-acquired pneumonia is reported to range between 2 and 7%. These patients are subject to a greater risk of intensive medical treatment and a higher mortality rate than patients who respond to primary treatment. We investigated 63 patients in a "real life scenario" who were admitted to the hospital after failure of primary outpatient therapy for community-acquired pneumonia. Thirty-three patients received intravenous standard therapy (betalactam 14, macrolide 3, levofloxacin 6, doxycycline 1, combinations 9 patients) while 30 patients were treated with intravenous moxifloxacin. The oral antibiotic pretreatment that failed most frequently was clarithromycin (n = 25), followed by amoxicillin/clavulanic acid (n = 16), cefixime (n = 10), cefuroxime/axetil (n = 5), doxycycline (3), cefpodoxime, and ciprofloxacin (2 each). There were no differences between the two groups in respect of age, gender, numbers of patients in nursing homes, numbers of patients with different underlying diseases (chronic bronchitis, coronary heart disease, diabetes mellitus, smoking, etc.), severity of pneumonia at the time of admission, numbers of patients requiring intensive care, and lethality. The group that underwent standard therapy experienced failure of the empirical intra-hospital antibiotic therapy more often during therapy [10 (30%) patients vs 2 (6%) in the moxifloxacin group, p = 0.009] and clinical failure of treatment on day 28 after initiation of therapy [7 (21%) patients vs 2 (6%) in the moxifloxacin group, p = 0.003]. In cases of failure of empirical preclinical antibiotic treatment for community-acquired pneumonia, subsequent intrahospital treatment with moxifloxacin is more successful than standard therapy in our study reflecting a "real life scenario".

Perioperative antibiotische Prophylaxe

Perioperative antibiotic prophylaxis in orthopaedics is only indicated if a foreign body such as a prosthetic joint remains in the operation site. For this indication first or second generation cephalosporins should be preferred. It is essential to administer the antibiotic within 30 min before incision. In the case of an extended intervention (more than 3 h) a repeated dose should be considered. It is evidence-based that prolonged perioperative antibiotic prophylaxis (more then 24 h) is not beneficial. To avoid the emergence of resistances or hygienic insufficiencies surveillance of surgical site infections should be enforced. Optimal conditions are necessary to achieve a rate of surgical site infection in orthopaedics below 1% in patients with normal infection risk profile.

Esophageal ATP synthase and keratinocyte growth factor gene expression changes after acid and bile-induced mucosal damage

OBJECTIVE AND DESIGN

Intramural gene expression changes may be critically involved in tissue damage, defense and repair after esophageal regurgitation. The aims were to characterize the consequences of short-term exposure to luminal bile, acid, or bile mixed with acid on the beta-ATPase, keratinocyte growth factor 1 (KGF-1) and KGF receptor (KGF-R) expressions within the mucosa and the muscle layer in a large animal model.

MATERIALS AND SUBJECTS

Esophageal segments of anesthetized dogs were exposed to saline (n = 3), diluted canine bile (n = 6), hydrochloric acid (n = 5) or bile + hydrochloric acid (n = 5), and tissue biopsies were taken at the end of the 180-min observation period. Semiquantitative reverse transcriptase polymerase chain reactions were carried out and the degree of histological damage was evaluated on the 0-16-grade Geisinger scoring scale.

RESULTS

Acid exposure was followed by a significant decrease in the level of beta-ATPase expression in the mucosa, and parallel increases in KGF-1 and KGF-R expression. Corresponding changes in the muscle layer were not significant. Bile alone evoked more severe tissue damage, with significantly decreased beta-ATPase levels in both the mucosa and the muscle, whereas the KGF-1 expression did not change significantly. The bile + acid treatment induced an intermediate state, with significant beta-ATPase transcription level decreases in both layers, while the mucosal KGF-1 expression was lower than that following acid treatment alone.

CONCLUSIONS

The acid-induced transcriptional level downregulation of mucosal beta-ATPase gene expression in the smooth muscle layer was exacerbated by bile, but the concomitant KGF and KGF-R gene expression changes may indicate the start of a consecutive repair process.

Serum factors regulate the expression of the proliferation-related genes alpha5 integrin and keratin 1, but not keratin 10, in HaCaT keratinocytes

In the highly coordinated programme of gene expression during keratinocyte proliferation and differentiation, alpha5 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 alpha5 integrin and K1/K10 was related to cell proliferation and differentiation. After release from cell quiescence the expression of alpha5 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 alpha5 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 alpha5 integrin and K1, but not of K10, in HaCaT cells. This information could be relevant to the understanding of normal epidermal differentiation.

Dithranol upregulates IL-10 receptors on the cultured human keratinocyte cell line HaCaT

OBJECTIVE

Dithranol is highly effective in the treatment of psoriasis, however its mode of action is still not well known. Since interleukin-8 and interleukin-10 are involved in the pathogenesis of psoriasis, the aim of our study was to investigate the effect of dithranol on interleukin-8, interleukin-10 mRNA production and interleukin-10 receptor expression of the HaCaT keratinocyte cell line which is commonly used in experiments examining the effects of therapeutic drugs on keratinocytes.

MATERIALS AND METHODS

Cultured HaCaT cells were treated with 0.1-0.5 microg/ml dithranol for 30 minutes. After 2 and 4 h total cellular RNA isolated from HaCaT cells was reverse transcribed (RT) to cDNA which was subjected to polymerase chain reaction (PCR) with specific primer pairs for interleukin-8, interleukin-10 and interleukin-10 receptor. For immunohistochemistry cultured HaCaT cells were stained with a monoclonal antibody against the human interleukin-10 receptor.

RESULTS

Our results showed that dithranol treatment did not change the highly elevated level of interleukin-8 mRNA of HaCaT cells. Interleukin-10 mRNA signal with RT-PCR could not be detected in HaCaT cells. Depending on the concentration dithranol increased the mRNA production of interleukin-10 receptors in HaCaT cells. This dithranol induced dose dependent upregulation of IL-10 receptors in HaCaT cells was also observed on the protein level using immunohistochemistry.

CONCLUSIONS

Since the interleukin-10 receptor expression of keratinocytes in psoriatic lesional skin is downregulated, the dithranol induced upregulation of the receptor in our model system might help to reveal the therapeutic action of the drug.

Characterization of tomato PHYB1 and identification of molecular defects in four mutant alleles

The structure of the gene encoding the apoprotein of phytochrome B (PHYB1) in tomato has been determined from genomic and cDNA sequences. In contrast to PHYA, PHYB1 lacks an intron upstream of the first ATG. A single transcription start site was found by 5' RACE at -116. Tomato PHYB1 spans 7 kb starting from the first ATG. The coding region is organized into four exons as for other angiosperm PHY. The deduced apoprotein consists of 1131 amino acids, with a molecular mass of 125.4 kDa. Tomato phytochrome B1 shares 78% and 74% identity with Arabidopsis phytochromes B and D, respectively. Along with the normally spliced full-length transcripts, sequences of reverse transcriptase-PCR clones revealed five types of alternative transcripts. Each type of alternative transcript was missing a considerable part of the coding region, including the chromophore-binding site. The four putative PHYB1 mutants in tomato, which are temporarily red-light insensitive (tri), were each confirmed to have a mutation in PHYB1. Each mutation arose from a different, single-base substitution. Allele tri1 is presumably a null because the mutation introduces a stop at codon 92. In tri3, val-238 is replaced by Phe. The importance of this valine residue is evidenced by the fact that the tri3 phenotype is as strong as that of tri1. Alleles tri2 and tri4 encode proteins truncated at their C-termini. The former lacks either 170 or 438 amino acids, depending upon which of two types of splicing occurs during transcript maturation, while the latter lacks 225.