The Syphilis Pandemic Prior to Penicillin: Origin, Health Issues, Cultural Representation and Ethical Challenges.

Syphilis is currently a treatable disease, with a low incidence in most developed countries, although the prevalence has increased recently, especially among men-who-have-sex-with-men. In many of the least developed countries, however, syphilis is still a major health problem, although the problem is not comparable to the desperate situation worldwide less than 80 years ago. At that time, and for many centuries previously, syphilis dramatically affected the lives and health of individuals and threatened the well-being of many societies. This review examines the aetiology, transmission, and many manifestations of syphilis from a historical perspective, emphasizing morbidity, treatment, psychosocial and cultural manifestations, as well as ethical issues uncovered in the clinical search for knowledge about the manifestations of the disease.

Exploration of novel candidate genes involved in epidermal keratinocyte differentiation and skin barrier repair in man.

A proper skin barrier function requires constant formation of stratum corneum, i.e. the outermost layer of epidermis composed of terminally differentiated keratinocytes. The complex process of converting proliferative basal keratinocytes into corneocytes relies on programmed changes in the activity of many well-established genes. Much remains however to be investigated about this process, e.g. in conjunction with epidermal barrier defects due to genetic errors as in ichthyosis. To this end, we re-analyzed two sets of microarray-data comparing altered gene expression in differentiated vs. proliferating keratinocytes and in the skin of patients with autosomal recessive congenital ichthyosis (ARCI) vs. healthy controls, respectively. We thus identified 24 genes to be upregulated in both sets of array and not previously associated with keratinocyte differentiation. For 10 of these genes (AKR1B10, BLNK, ENDOU, GCNT4, GLTP, RHCG, SLC15A1, TMEM45B, TMEM86A and VSNL1), qPCR analysis confirmed the array results and subsequent immunostainings of normal epidermis showed superficial expression of several of the proteins. Furthermore, induction of keratinocyte differentiation using phorbol esters (PMA) resulted in increased expression of eight of the genes, whereas siRNA silencing of PPARδ, a transcription factor supporting differentiation, had the opposite effect. In summary, our results identify ten new candidate genes seemingly involved in human epidermal keratinocyte differentiation and possibly important for epidermal repair in a genetic skin disease characterized by barrier failure.

Meta-Analysis of Mutations in ALOX12B or ALOXE3 Identified in a Large Cohort of 224 Patients.

The autosomal recessive congenital ichthyoses (ARCI) are a nonsyndromic group of cornification disorders that includes lamellar ichthyosis, congenital ichthyosiform erythroderma, and harlequin ichthyosis. To date mutations in ten genes have been identified to cause ARCI: TGM1, ALOX12B, ALOXE3, NIPAL4, CYP4F22, ABCA12, PNPLA1, CERS3, SDR9C7, and SULT2B1. The main focus of this report is the mutational spectrum of the genes ALOX12B and ALOXE3, which encode the epidermal lipoxygenases arachidonate 12-lipoxygenase, i.e., 12R type (12R-LOX), and the epidermis-type lipoxygenase-3 (eLOX3), respectively. Deficiency of 12R-LOX and eLOX3 disrupts the epidermal barrier function and leads to an abnormal epidermal differentiation. The type and the position of the mutations may influence the ARCI phenotype; most patients present with a mild erythrodermic ichthyosis, and only few individuals show severe erythroderma. To date, 88 pathogenic mutations in ALOX12B and 27 pathogenic mutations in ALOXE3 have been reported in the literature. Here, we presented a large cohort of 224 genetically characterized ARCI patients who carried mutations in these genes. We added 74 novel mutations in ALOX12B and 25 novel mutations in ALOXE3. We investigated the spectrum of mutations in ALOX12B and ALOXE3 in our cohort and additionally in the published mutations, the distribution of these mutations within the gene and gene domains, and potential hotspots and recurrent mutations.

Ichthyosis: A Road Model for Skin Research.

The understanding of monogenetic disorders of cornification, including the group of diseases called ichthyoses, has expanded greatly in recent years. Studies of the aetiology of more than 50 types of ichthyosis have almost invariably uncovered errors in the biosynthesis of epidermal lipids or structural proteins essential for normal skin barrier function. The barrier abnormality per se may elicit epidermal inflammation, hyperproliferation and hyperkeratosis, potentially contributing to the patient's skin symptoms. Despite this and other new knowledge about pathomechanisms, treatment of ichthyosis often remains unsatisfactory. This review highlights a series of approaches used to elucidate the pathobiology and clinical consequences of different types of ichthyosis, and related diseases with the ultimate goal of finding new and better treatments.

Patients with congenital ichthyosis and TGM1 mutations overexpress other ARCI genes in the skin: Part of a barrier repair response?

Autosomal recessive congenital ichthyosis (ARCI) is a group of monogenic skin disorders caused by mutations in any of at least 12 different genes, many of which are involved in the epidermal synthesis of ω-O-acylceramides (acylCer). AcylCer are essential precursors of the corneocyte lipid envelope crosslinked by transglutaminase-1 (TGm-1), or a yet unidentified enzyme, for normal skin barrier formation. We hypothesized that inactivating TGM1 mutations will lead to a compensatory overexpression of the transcripts involved in skin barrier repair, including many other ARCI-causing genes. Using microarray, we examined the global mRNA expression profile in skin biopsies from five ARCI patients with TGM1 mutations and four healthy controls. There were a total of 599 significantly differentially expressed genes (adjusted P < 0.05), out of which 272 showed more than 1.5 log2fold-change (FC) up- or down-regulation. Functional classification of the latter group of transcripts showed enrichment of mRNA encoding proteins mainly associated with biological pathways involved in keratinocyte differentiation and immune response. Moreover, the expression of seven out of twelve ARCI-causing genes was significantly increased (FC = 0.98-2.05). Also, many of the genes involved in keratinocyte differentiation (cornified envelope formation) and immune response (antimicrobial peptides and proinflammatory cytokines) were upregulated. The results from the microarray analysis were also verified for selected genes at the mRNA level by qPCR and at the protein level by semi-quantitative immunofluorescence. The upregulation of these genes might reflect a compensatory induction of acylCer biosynthesis as a part of a global barrier repair response in the patient's epidermis.

Inherited Nonsyndromic Ichthyoses: An Update on Pathophysiology, Diagnosis and Treatment.

Hereditary ichthyoses are due to mutations on one or both alleles of more than 30 different genes, mainly expressed in the upper epidermis. Syndromic as well as nonsyndromic forms of ichthyosis exist. Irrespective of etiology, virtually all types of ichthyosis exhibit a defective epidermal barrier that constitutes the driving force for hyperkeratosis, skin scaling, and inflammation. In nonsyndromic forms, these features are most evident in severe autosomal recessive congenital ichthyosis (ARCI) and epidermolytic ichthyosis, but to some extent also occur in the common type of non-congenital ichthyosis. A correct diagnosis of ichthyosis-essential not only for genetic counseling but also for adequate patient information about prognosis and therapeutic options-is becoming increasingly feasible thanks to recent progress in genetic knowledge and DNA sequencing methods. This paper reviews the most important aspects of nonsyndromic ichthyoses, focusing on new knowledge about the pathophysiology of the disorders, which will hopefully lead to novel ideas about therapy.

Quantitative image analysis of protein expression and colocalisation in skin sections.

Immunofluorescence (IF) and in situ proximity ligation assay (isPLA) are techniques that are used for in situ protein expression and colocalisation analysis, respectively. However, an efficient quantitative method to analyse both IF and isPLA staining on skin sections is lacking. Therefore, we developed a new method for semi-automatic quantitative layer-by-layer measurement of protein expression and colocalisation in skin sections using the free open-source software CellProfiler. As a proof of principle, IF and isPLA of ichthyosis-related proteins TGm-1 and SDR9C7 were examined. The results indicate that this new method can be used for protein expression and colocalisation analysis in skin sections.

Revertant mosaicism repairs skin lesions in a patient with keratitis-ichthyosis-deafness syndrome by second-site mutations in connexin 26.

Revertant mosaicism (RM) is a naturally occurring phenomenon where the pathogenic effect of a germline mutation is corrected by a second somatic event. Development of healthy-looking skin due to RM has been observed in patients with various inherited skin disorders, but not in connexin-related disease. We aimed to clarify the underlying molecular mechanisms of suspected RM in the skin of a patient with keratitis-ichthyosis-deafness (KID) syndrome. The patient was diagnosed with KID syndrome due to characteristic skin lesions, hearing deficiency and keratitis. Investigation of GJB2 encoding connexin (Cx) 26 revealed heterozygosity for the recurrent de novo germline mutation, c.148G > A, p.Asp50Asn. At age 20, the patient developed spots of healthy-looking skin that grew in size and number within widespread erythrokeratodermic lesions. Ultra-deep sequencing of two healthy-looking skin biopsies identified five somatic nonsynonymous mutations, independently present in cis with the p.Asp50Asn mutation. Functional studies of Cx26 in HeLa cells revealed co-expression of Cx26-Asp50Asn and wild-type Cx26 in gap junction channel plaques. However, Cx26-Asp50Asn with the second-site mutations identified in the patient displayed no formation of gap junction channel plaques. We argue that the second-site mutations independently inhibit Cx26-Asp50Asn expression in gap junction channels, reverting the dominant negative effect of the p.Asp50Asn mutation. To our knowledge, this is the first time RM has been reported to result in the development of healthy-looking skin in a patient with KID syndrome.

Spectrum of Autosomal Recessive Congenital Ichthyosis in Scandinavia: Clinical Characteristics and Novel and Recurrent Mutations in 132 Patients.

Autosomal recessive congenital ichthyosis (ARCI) represents a heterogeneous group of rare disorders of cornification with 3 major subtypes: harlequin ichthyosis (HI), lamellar ichthyosis (LI) and congenital ichthyosiform erythroderma (CIE). A 4th subtype has also been proposed: pleomorphic ichthyosis (PI), characterized by marked skin changes at birth and subsequently mild symptoms. In nationwide screenings of suspected cases of ARCI in Denmark and Sweden, we identified 132 patients (age range 0.1-86 years) classified as HI (n = 7), LI (n = 70), CIE (n = 17) and PI (n = 38). At birth, a collodion membrane or similar severe hyperkeratosis was reported in almost all patients with HI and LI, and in nearly half of patients with CIE and PI. Persistent ectropion was more common in HI (85%) and LI (57%), than in CIE (35%) and PI (5%). Anhidrosis was a frequent problem in all 4 groups (58-100%). A scoring (0-4) of ichthyosis/ery-thema past infancy showed widely different mean values in the subgroups: HI (3.2/3.1), LI (2.4/0.6), CIE (1.8/1.6), PI (1.1/0.3). Novel or recurrent mutations were found in 113 patients: TGM1 (n = 56), NIPAL4 (n = 15), ALOX12B (n = 15), ABCA12 (n = 8), ALOXE3 (n = 9), SLC27A4 (n = 5), CYP4F22 (n = 3), PNPLA1 (n = 1) and ABHD5 (n = 1). In conclusion, by performing a deep phenotyping and gene screening, ARCI can be definitely diagnosed in 85% of cases in Scandinavia, with a prevalence of 1:100,000 and > 8 different aetiologies.

Palmoplantar keratoderma of the Gamborg-Nielsen type is caused by mutations in the SLURP1 gene and represents a variant of Mal de Meleda.

Palmoplantar keratoderma of the Gamborg-Nielsen type (PPK-GN) is a rare autosomal recessive skin disorder described in patients from Sweden. Mal de Meleda (MDM) is also a rare autosomal recessive inherited PPK first reported in 5 families from the island of Meleda. The 2 conditions phenotypically overlap and are characterised by palmoplantar erythematous hyperkeratotic plaques. The genetic background giving rise to PPK-GN has hitherto been unknown, whereas MDM is known to be caused by mutations in the gene encoding secreted Ly-6/uPAR-related protein 1, SLURP-1. In the present study we scrutinised individuals affected by PPK-GN for mutations in the SLURP1 gene and identified 2 different mutations. Fourteen Swedish patients were homozygous for a previously described mutation, c.43T>C, while one individual was a compound heterozygote with one copy of a novel mutation, c.280T>A, in addition to one copy of the c.43T>C mutation. Hereby we confirm that PPK-GN is an allelic variant of MDM.

Interactions between FATP4 and ichthyin in epidermal lipid processing may provide clues to the pathogenesis of autosomal recessive congenital ichthyosis.

BACKGROUND: Autosomal recessive congenital ichthyosis (ARCI) is caused by mutations in ≥10 different genes, of which transglutaminase-1 (TGM1) predominates. A rare form is ichthyosis prematurity syndrome (IPS) caused by mutations in SLC27A4 encoding fatty acid transporter protein 4 (FATP4), believed to be an acyl-CoA synthetase activating long- and very-long-chain FA. Another ARCI is caused by mutations in NIPAL4, coding for ichthyin, which is proposed to be a magnesium transporter or a trans-membrane receptor. A possible interaction between FATP4 and ichthyin has not been studied before. OBJECTIVE: To find common denominators in the pathogenesis of ARCI. METHODS: FATP4 and ichthyin were analyzed by immunofluorescence and proximity ligation assay (PLA) in healthy and ARCI patient skin and in in vitro models of ARCI epidermis. RESULTS: Both proteins were expressed in the upper stratum granulosum of normal epidermis and PLA confirmed a close interaction between FATP4 and ichthyin. In IPS skin lacking FATP4 we found reduced ichthyin expression and this finding could be reproduced in organotypic epidermis with siRNA silenced SLC27A4. In contrast, increased FATP4 staining was found in patients with ichthyin (NIPAL4) mutations and in organotypic epidermis with silenced NIPAL4. In patients with TGM1 mutations, the expression of both FATP4 and ichthyin was increased, but the PLA signal was low probably indicating a malfunctioning protein interaction. CONCLUSION: Our study suggests that FATP4, ichthyin and TGM1 interact in lipid processing essential for maintaining the epidermal barrier function. It is also hypothesized that ichthyin serves as Mg(2+)-transporter for FATP4 in this process.

Genotype-phenotype correlations emerging from the identification of missense mutations in MBTPS2.

Missense mutations affecting membrane-bound transcription factor protease site 2 (MBTPS2) have been associated with Ichthyosis Follicularis with Atrichia and Photophobia (IFAP) syndrome with or without BRESHECK syndrome, with keratosis follicularis spinulosa decalvans, and Olmsted syndrome. This metalloprotease activates, by intramembranous trimming in conjunction with the protease MBTPS1, regulatory factors involved in sterol control of transcription and in cellular stress response. In this study, 11 different MBTPS2 missense mutations detected in patients from 13 unrelated families were correlated with the clinical phenotype, with their effect on cellular growth in media without lipids, and their potential role for sterol control of transcription. Seven variants were novel [c.774C>G (p.I258M); c.758G>C (p.G253A); c.686T>C (p.F229S); c.1427T>C (p.L476S); c.1430A>T (p.D477V); c.1499G>A (p.G500D); c.1538T>C (p.L513P)], four had previously been reported in unrelated sibships [c.261G>A (p.M87I); c.1286G>A (p.R429H); c.1424T>C (p.F475S); c.1523A>G (p.N508S)]. In the enzyme, the mutations cluster in transmembrane domains. Amino-acid exchanges near the active site are more detrimental to functionality of the enzyme and, clinically, associated with more severe phenotypes. In male patients, a genotype-phenotype correlation begins to emerge, linking the site of the mutation in MBTPS2 with the clinical outcome described as IFAP syndrome with or without BRESHECK syndrome, keratosis follicularis spinulosa decalvans, X-linked, Olmsted syndrome, or possibly further X-linked traits with an oculocutaneous component.

Generalized and naevoid epidermolytic ichthyosis in Denmark: clinical and mutational findings.

A Danish-Swedish collaboration was established to identify and classify a Danish cohort of patients with epidermolytic ichthyosis, also known as epidermolytic hyperkeratosis. Patients were recruited from 5 dermatology departments in Denmark, and data were obtained using a structured questionnaire and a systematic examination together with photographs, histopathological descriptions and blood samples for mutational analysis. Sixteen patients from 12 families with generalized or naevoid epidermolytic ichthyosis and ichthyosis bullosa of Siemens were identified. Five families had mutations in K1 and 6 families had mutations in K10. Nine patients had been treated with systemic retinoids (etretinate, acitretin, isotretinoin or alitretinoin), but only 3 patients had acceptable treatment responses and chose to continue therapy. In conclusion epidermolytic ichthyosis is a rare disease with a prevalence of approximately 1 in 350,000 in Denmark and a high percentage of de novo mutations (75%). We identified 4 novel disease-causing mutations.