The epidermal phenotype during initiation of the psoriatic lesion in the symptomless margin of relapsing psoriasis

Research "recover from illness defense complex" helper T cell immune mechanisms based on the "Fuxie" theory clearing away heat evil thoroughly nourishing kidney treatment of recurrent blood-heat syndrome Psoriasis

INTRODUCTION

Psoriasis vulgaris (PV) is a chronic, painful, disfiguring, and disabling dermatological disease, which affects the physical and mental health of patients and impacts their quality of life. Current conventional systemic therapies can be costly, present risks of side effects, have limited efficacy and commonly recur following treatment cessation. Some Chinese herbal medicine therapies have shown therapeutic benefits for psoriasis vulgaris, including relieving symptoms and improving quality of life, and a potential of reducing relapse rate. However, explicit evidence has not yet been obtained.

METHODS AND ANALYSIS

This is a pilot randomized controlled trial with the objective of investigating the effect of Jia Wei Liang Xue Xiao Feng San granules on relapse rate of recurrent PV and the correlation between Psoriasis area severity index (PASI) and key psoriasis-related cytokine changes and the number of cells. A total of 102 participants were recruited for this study, including 72 patients with recurrent PV, 15 healthy volunteers and 15 patients with psoriasis vulgaris who have recovered for more than 1 year. A total of 72 patients, with recurrent PV, will be randomized (1:1) to receive the oral Chinese herbal medicine Jia Wei Liang Xue Xiao Feng San or the oral Acitretin Capsule treatments for a period of 8 weeks. After this period, participants whose PASI scores improvement reached more than 75%, will undergo a 52-week follow-up phase.The primary outcome measures are as follows:The secondary study outcomes will include:This trial may provide a novel regimen for recurrent PV patients if the granules decrease recurrence rate without further adverse effects.

ETHICS AND DISSEMINATION

The ethics approval was provided by the Sichuan Traditional Chinese medicine regional ethics review committee. The ethics approval number is 2018KL-055. The design and the results of the study will be disseminated through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry (ChiCTR1900022766).

Rise in dermal CD11c+ dendritic cells associates with early-stage development of psoriatic lesions

There is limited information available regarding the phenotype and function of leukocytes involved in the earliest stages of psoriatic lesion development. In this study, we examined the presence of different types of leukocytes in psoriatic point lesions collected at three 1-week interval time points from a recent and simultaneously formed group of point lesions. The cells were quantified and compared with K16 expression and epidermal thickness, both typically increased in this disease and considered as hallmarks. We found a significant correlation between K16⁺ cell increment and the increase in epidermal thickness in the timeframe of 14 days. The change in CD3⁺, CD4⁺, and CD8⁺ T-cell numbers in the dermis showed a significant association with these two features from d7 to d14, whereas in the epidermis only CD8⁺ T cells demonstrated a significant correlation. Remarkably, the relationship between T cells and disease progression was preceded by a significant correlation of CD11c⁺ dendritic cells (DCs) with K16 expression and epidermal thickness from baseline onwards. Interestingly, there was also a numeric correlation of CD11c⁺ DCs with the CD3⁺ T-cell shifts from d7 to d14. A significant correlation was also found between dermal CD14⁺ cells and K16 expression from d7 to d14. BDCA-2⁺ plasmacytoid DCs were absent in non-lesional skin, but found at low numbers in most lesions. The change in plasmacytoid DC or neutrophil numbers did not correlate with lesion development. In conclusion, our study suggests a relevant role for T cells, and in particular dermal CD11c⁺ DCs, in the earliest stage of psoriatic lesion development.

Epidermal kinetic alterations required to generate the psoriatic phenotype: a reappraisal

OBJECTIVES

Although there have been major advances in understanding immunopathogenesis of psoriasis, the basic processes causing psoriatic morphology remain to be identified.

MATERIALS AND METHODS

Our group has designed a systematic review of studies (1962-2009) on keratinocyte kinetics in psoriasis. We obtained data from MEDLINE, PubMed, Current Contents, reference lists and specialist textbooks. A general equation for evolution of the differentiated epidermis has been analysed. Necessary conditions for observed qualitative change in homeostasis between normal skin and established psoriatic lesions were determined.

RESULTS AND DISCUSSION

Increase in the number of cell divisions (or imbalance in symmetric division rates of committed progenitor cells) and/or decrease in physiological apoptosis in the germinative compartment, together with feedback loops that limit thickening of the skin, are required to generate psoriatic morphology, that is, to increase the absolute size but decrease relative size of the differentiated cell compartment with respect to the germinative compartment.

Integrated network analysis of transcriptomic and proteomic data in psoriasis

BACKGROUND

Psoriasis is complex inflammatory skin pathology of autoimmune origin. Several cell types are perturbed in this pathology, and underlying signaling events are complex and still poorly understood.

RESULTS

In order to gain insight into molecular machinery underlying the disease, we conducted a comprehensive meta-analysis of proteomics and transcriptomics of psoriatic lesions from independent studies. Network-based analysis revealed similarities in regulation at both proteomics and transcriptomics level. We identified a group of transcription factors responsible for overexpression of psoriasis genes and a number of previously unknown signaling pathways that may play a role in this process. We also evaluated functional synergy between transcriptomics and proteomics results.

CONCLUSIONS

We developed network-based methodology for integrative analysis of high throughput data sets of different types. Investigation of proteomics and transcriptomics data sets on psoriasis revealed versatility in regulatory machinery underlying pathology and showed complementarities between two levels of cellular organization.

The universal detection of antigens from one skin biopsy specimen

BACKGROUND

Immunohistochemistry is an important tool in dermatology but is limited. Certain antigens can only be preserved in formalin-fixed paraffin-embedded sections, while others can only be detected on frozen sections, resulting in situations where two biopsies are needed. We aimed to develop a technique for universal detection of different antigens out of just one biopsy specimen.

METHODS

Single biopsies were obtained from lesional skin of patients with psoriasis. Standard sample procedures for frozen and paraffin-embedded sections were used. To convert frozen tissue into paraffin-embedded sections, the biopsy specimen was disposed of the embedding medium and subsequently fixed in 10% neutral buffered formalin. We applied various antigen retrieval techniques with alkaline solutions. The differential expression of keratin 10, keratin 15, CD3, CD26 and human beta defensin-2 (HBD-2) was examined using immunohistochemical staining.

RESULTS

We showed that keratin 10 and 15 can be stained on both frozen and paraffin-embedded sections. Staining of paraffin-embedded sections required unmasking with trypsin and Tris-buffered saline Tween solution, respectively. CD3 and CD26 can only be detected on frozen sections, while HBD-2 can only be detected on paraffin-embedded sections.

CONCLUSION

We have described a straightforward technique that gives us the opportunity to use just one biopsy specimen to obtain frozen sections as well as paraffin-embedded sections.

Early inflammatory changes in the "perilesional skin" of psoriatic plaques: is there interaction between dendritic cells and keratinocytes?

Early inflammatory changes in psoriatic plaques were investigated immunohistochemically by studying the normal-appearing skin adjacent to the plaques (perilesional skin), lesional skin, and distant uninvolved skin from psoriasis patients. Perilesional epidermis contained numerous CD1a-positive Langerhans cells, some of which expressed HLA-DR, CD83, CD80, and CD86, at the same time expressing Langerin. There were also numerous CD83-positive, CD11c-positive, Langerin-negative dendritic cells (DCs) in the epidermal-dermal junction of perilesional skin. CD3-positive T lymphocytes were sparse in the perilesional skin. Perilesional epidermis expressed keratin K6 and K16, inflammatory keratins, and C/EBPbeta, a transcription factor related to inflammatory cytokines. Our results demonstrated the abundant distribution of activated DCs in the perilesional skin of psoriatic plaques, where early inflammatory changes occur in the epidermal keratinocytes, which suggests their involvement in the provocation of epidermal inflammation in the perilesional epidermis and further pathogenic roles in the formation of psoriatic plaques.

The evolution of the psoriatic lesion

Psoriasis comprises a host of abnormalities, and various aspects of the pathogenesis of psoriasis have been suggested to be of primary relevance. The aim of this review is to identity driving factors in the pathogenesis of psoriasis and to explore the dynamics of processes eventually resulting in a psoriatic lesion. In this review observations on the evolution from the symptomless skin to lesional skin in patients with psoriasis will be integrated with observations in various animal models of psoriasis.

The Efficacy and Safety of Topically Applied Indigo Naturalis Ointment in Patients with Plaque-Type Psoriasis

BACKGROUND

It has been reported in the Chinese literature that indigo naturalis exhibits potential antipsoriatic effects in systemic therapy.

OBJECTIVE

To evaluate the efficacy and safety of topically applied indigo naturalis on treating plaque-type psoriasis and to analyze the histological change in skin tissues.

METHODS

Fourteen patients with chronic plaque psoriasis were enrolled. The patients were topically applied with either indigo naturalis ointment or vehicle ointment on contralateral skin lesions daily for 8 weeks. Efficacy was evaluated on the basis of the clinical scores, including induration, scaling, erythema and clearing percentage. At the end of treatment, skin punch biopsies were taken and prepared for the immunohistochemical analysis.

RESULTS

A significant reduction in clinical scores was achieved with topically applied indigo naturalis ointment. Analysis of biopsies showed a marked improvement of skin histology. The expressions of proliferating marker Ki-67 and inflammatory marker CD3 were decreased, but the differentiation marker such as filaggrin was increased in the epidermis after indigo naturalis ointment treatment.

CONCLUSIONS

The results suggest that topical application of indigo naturalis ointment may be a novel, safe and effective therapy for psoriasis that is mediated, at least in part, by modulating the proliferation and differentiation of keratinocytes in epidermis, as well as by inhibiting the infiltration of T lymphocytes and therefore the subsequent inflammatory reactions in psoriatic lesions.

Assessment of epidermal subpopulations and proliferation in healthy skin, symptomless and lesional skin of spreading psoriasis

BACKGROUND

The margin zone in spreading psoriatic lesions has frequently been used as a model to study the changes in epidermal proliferation, keratinization and inflammation during the transition from symptomless to lesional skin. However, the dynamics of the changes in the epidermal subpopulations-basal cells, transit amplifying cells and differentiated cells-have not been studied in the transition between symptomless and lesional skin.

OBJECTIVES

To quantify in a dynamic model of the margin zone in psoriasis the characteristics of these subpopulations with respect to epidermal proliferation and differentiation.

METHODS

From seven patients with active psoriasis, biopsies were taken from the distant uninvolved skin, outer margin, inner margin and centre of a spreading psoriatic plaque. Frozen sections were labelled immunofluorescently using direct immunofluorescence for Ki-67 and beta1 integrin and the Zenon labelling technique for keratin 6, 10 and 15. Digital photographs of the stained sections were quantitatively analysed.

RESULTS

In the distant uninvolved skin the expression of beta1 integrin was decreased and keratin 15 expression was lost. In this area suprabasal cells expressed beta1 integrin and in the outer margin suprabasal cells expressed Ki-67. From the outer to the inner margin of the psoriasis plaque, which coincided with the appearance of the clinical lesion, there was a significant change in the various markers. The patchy expression of keratin 6 in the inner margin became homogeneous in the centre of the psoriasis plaque and here was also coexpression of keratin 6 and keratin 10 in a single cell.

CONCLUSIONS

The present study provides additional evidence that the distant uninvolved skin has a prepsoriatic phenotype, which is the first step in a psoriatic cascade. The cascade between symptomless and lesional skin comprises first an abnormality in inflammation with involvement of beta1 integrin-dim cells (transit amplifying cells) subsequently eliciting an enlarged germinative compartment with increased recruitment of cycling epidermal cells and focal expression of proliferation-associated keratins, ultimately culminating in a more-or-less homogeneous epidermis with massive recruitment of cycling epidermal cells and proliferation-associated keratinization.

Calcipotriol/betamethasone dipropionate for the treatment of psoriasis

The two-compound product calcipotriol/betamethasone dipropionate is arising as a first-line treatment for mild-to-moderate plaque psoriasis. Its beneficial action is attributed to the synergistic effect of its components on keratinocyte proliferation and differentiation, and on inflammation. The good tolerability of the two-compound product is thought to be due to the anti-inflammatory effect of betamethasone. Evidence from short-term (4-12 weeks) and long-term use (> 1 year) has shown a good safety profile. Areas such as the face or skin folds, which are sensitive to the components of the combination, should be avoided. Finally, it is unsuitable for use in unstable psoriasis, in which potent steroids may lead to an increased inflammatory response.

Keratin 16 Expression in Epidermal Melanocytes of Normal Human Skin

Although the prevailing dogma states that keratin filaments are the hallmark of keratinocytes and other epithelial cells, recent publications suggest that they may be expressed by a variety of normal and malignant cells of different embryonic origin. Keratin expression has been reported in fibroblasts and endothelial cells as well as in various sarcomas. Also, some human melanomas express keratins in addition to the traditional diagnostic markers of differentiation, such as S-100 and melanocyte-specific antigens. Many studies have shown that cultured cells obtained from various melanomas express keratin. Most recently, keratin expression has also been shown in cultured melanocytes of normal skin. We now report that normal human melanocytes in vivo express keratin 16 (K16) but not keratins 1, 5, 8, 10, 14, or even keratin 6, the type II partner that is normally expressed with K16 in keratinocytes. Similarly, melanocytes in vitro express K16 but not K6. Keratin 16 expression in vivo was present in basal melanocytes in specimens derived from donors (0-77 years) and from different anatomic locations, suggesting that keratin 16 is constitutively expressed by all melanocytes. It appears that keratin expression may be more prevalent than previously assumed, and that these cytoskeletal filaments may play important roles in tissues and cells other than epithelia.

Phenotypical and Functional Differences in Germinative Subpopulations Derived from Normal and Psoriatic Epidermis

A model that explains how maintenance of normal homeostasis in human epidermis is achieved describes a heterogeneous cell population of stem cells (SC) and transit amplifying cells (TAC). There must be a tightly regulated balance between SC self-renewal and the generation of TAC that undergo a limited number of divisions before giving rise to postmitotic, terminally differentiated cells. To investigate whether this balance is disturbed in psoriatic epidermis, we have characterized flow sorted enriched SC and TAC using immunocytochemistry, flow cytometry, and real-time quantitative PCR. Our data demonstrate phenotypical and functional differences in SC (beta(1)-integrin bright) and TAC (beta(1)-integrin dim) enriched fractions between normal and psoriatic keratinocytes. Some of these were expected, such as mRNA levels of keratins 6 and 10 and of the Ki-67 antigen. Most remarkable were differences in phenotype of the psoriatic TAC compared with TAC from normal skin. These subpopulations also displayed striking differences following culture. Downregulation of markers associated with the regenerative phenotype (psoriasin, elafin, psoriasis-associated fatty acid binding protein) in cultured psoriatic dim cells in the absence of hyperproliferation suggests that proliferation and regenerative maturation are coupled. From these results, in combination with our earlier findings, we propose a model for epidermal growth control in which TAC play a crucial role.

K16 expression in uninvolved psoriatic skin: a possible marker of pre-clinical psoriasis

BACKGROUND

K16, a type I keratin, is upregulated in hyperproliferative states including psoriasis. It has been used as a marker of psoriasis and its expression is upregulated in relapsing psoriasis and downregulating in resolving. We evaluated non-lesional psoriatic skin for K16 expression.

METHODS

Sixty-seven non-lesional and lesional skin samples from patients with psoriasis and normal skin from 19 non-psoriatic patients were studied by immunohistochemistry on frozen sections with K16.

RESULTS

Seventeen of 19 normal skin samples showed staining of basal cells in the deeper part of the rete ridges. Sixty-two non-lesional psoriatic skin samples showed intense basal staining of K16. Of the remaining five non-lesional samples, diffuse intense suprabasal staining in one, pan-epidermal staining in two, and no staining was seen in two samples. Suprabasal (37), diffuse (14), sandwich (12), and basal (3) pattern staining were seen in psoriatic skin. One psoriatic skin sample did not show any expression.

CONCLUSION

Our results demonstrate that K16 expression is also observed in non-lesional psoriatic skin and may serve as a marker of preclinical psoriasis.

Polymorphisms in the interleukin-20 gene: relationships to plaque-type psoriasis

We analyzed the frequency of single-nucleotide polymorphisms (SNPs) at positions -1053 (rs 2981572), 1380 (rs 2981573), 1462 (rs 2232360), and 3978 (rs 1518108) of the human interleukin-20 (IL-20) gene by tetraprimer ARMS-PCR method. A significant association between patients with psoriasis and the G allele at position -1053 (P<0.05) was established. The pairwise linkage disequilibrium (LD) matrix showed that the nearly complete LD was present within the polymorphisms at positions -1053, 1380, and 1462 of the IL-20 gene. We found that patients with plaque psoriasis had a higher frequency of the HT3 GAA haplotype (P<0.01, OR 2.341, 95% CI: 1.346-4.074) compared to the control group. Likewise, the HT3 GAA haplotype was associated with an increased risk of early-onset psoriasis (P<0.01, OR 2.305, 95% CI: 1.285-4.132), late onset of disease (P<0.01, OR 2.542, 95% CI: 1.266-5.102), familial psoriasis (P<0.02, OR 2.220, 95% CI: 1.249-3.945), and sporadic disease (P<0.01, OR 2.523, 95% CI: 1.390-4.580). Our data indicate that IL-20 gene polymorphisms should have a role in determining susceptibility to plaque-type psoriasis. The possible role of the studied SNPs in the regulation of the expression of IL-20 is unknown yet and needs further studies.

Fluorescence imaging of reepithelialization from skin explant cultures on acellular dermis

Reconstituted skin models are valuable tools in studies of cutaneous biology although they are not generally devised to visualize and quantify the time course of reepithelialization. We describe a skin explant culture technique coupled with vital microscopy allowing sequential imaging of epithelial outgrowth while maintaining the tissue in culture. Radial expansion of neo-epidermis was initiated from a 2-mm skin punch biopsy explanted onto acellular human dermis and maintained at the air-liquid interface in serum-containing keratinocyte medium. Microscopic viewings and surface area measurements of newly formed epidermis were performed repeatedly using fluorescein-based cell staining and subsequent image analysis. The labeling and visualization procedures did not interfere with neo-epidermal growth or tissue architecture. In order to appraise the versatility of the model, we studied the effect of epidermal growth factor supplementation on the course of skin resurfacing as related to tissue morphology and proliferative activity over a 10-day cultivation period. Exogenous epidermal growth factor at 10 ng/ml increased the radial outgrowth rate (mean, + 13.3 percent), papillomatosis index (+ 19.2 percent), epithelial thickness (+ 49.8 percent), and fraction of Ki-67 positive basal cells (+ 18.4 percent) in neo-epidermis produced from a biopsy of normal human skin. The contribution of this miniaturized and convenient format for concurrent studies of dynamic and qualitative features of neo-epidermis should be a useful complement to existing assays of epidermalization.

The effect of the combination of calcipotriol and betamethasone dipropionate versus both monotherapies on epidermal proliferation, keratinization and T-cell subsets in chronic plaque psoriasis

Several reports have indicated that the combination of calcipotriol ointment and potent or ultrapotent corticosteroids are more effective and better tolerated, as compared to the monotherapies. The aim of the present study was to find out the effect of combination of calcipotriol ointment once daily and betamethasone dipropionate ointment once daily vs. the effect of twice-daily applications of each of the two treatments as monotherapy during a four-week treatment period. Seven patients with chronic plaque psoriasis were included for treatment with the three treatment schedules. Biopsies were taken before treatment and after four weeks of treatment, and markers for epidermal proliferation (Ki-67) and epidermal differentiation (keratin-10) were studied using a quantitative image analysis, and T-cell subsets in epidermis and dermis (CD4, CD8, CD25, CD45RO, CD45RA, CD94, CD161, and CD2) were studied using immunohistochemical scoring. The most impressive clinical result was reached with the combination. Calcipotriol proved to have a major effect on the proliferation marker Ki-67 and differentiation marker keratin-10, whereas the effect on T-cell subsets was more selective with major reductions of CD45RO(+) and CD8(+) T cells. In contrast, the effect of betamethasone dipropionate on the epidermis was restricted to a normalization of differentiation with a highly significant increase of keratin-10 positive epidermal surface without a significant effect on Ki-67 positive nuclei, and the effect on T-cell subsets was restricted to a reduction of natural killer T-cell receptors designated by CD94 and CD161 in the epidermis. The combination of the two treatments did not affect the proliferation marker Ki-67 and keratinization marker keratin-10, beyond the effect of calcipotriol monotherapy. However, the combination had a profound effect on, virtually, all T-cell subsets, beyond the effect of the monotherapies. It is concluded that the action spectra of calcipotriol and betamethasone on the psoriatic plaque are different and that the combination has effects on T-cell subsets, beyond the addition of the effects of monotherapies.

PUVA downregulates whn expression in primary mouse keratinocytes

Psoralen photochemotherapy (PUVA) is one of the most efficient treatment regimens for psoriasis and other skin diseases. In order to evaluate keratinocyte-specific PUVA effects, we investigated the impact of clinically relevant PUVA doses on whn, the 'nude' gene. This transcription factor plays an important role in epidermal homeostasis, and epidermal whn over-expression results in a psoriasis-like phenotype. We demonstrated a persistent down-regulation of whn mRNA 48-72 h after PUVA treatment but not after UVA alone. Using transgenic animals, we also demonstrated dose-dependent down-regulation of whn promoter activity. Finally, whn-null ('nude') keratinocytes were more resistant to PUVA-induced suppression of DNA synthesis than wild-type cells. Our results suggest that whn suppression may be involved in mediating the anti-proliferative effect of PUVA on keratinocytes.

The influence of a topical corticosteroid on short-contact high-dose dithranol therapy

BACKGROUND

Dithranol (anthralin) has been known to be effective in the treatment of psoriasis for more than 80 years. However, perilesional and uninvolved skin often show irritation during dithranol treatment, which limits its use. As the relapse rate of psoriasis is worsened by adding corticosteroids to a dithranol regimen, the use of topical corticosteroids to reduce dithranol irritation is controversial.

OBJECTIVES

The aim of the present study was to investigate the clinical and cell biological effect of clobetasol-17-propionate 0.05% ointment on dithranol-treated lesional and perilesional skin.

METHODS

For 17 consecutive days, 2% dithranol cream was applied on two test sites. A third site was left untreated on all participating patients (n = 8). All sites consisted of a psoriasis lesion as well as a 3-cm zone of perilesional skin localized on the back. After 1 h, the cream was washed off, and subsequently one of the dithranol-treated sites was treated once a day with clobetasol-17-propionate 0.05% ointment. The second site was treated once daily with the vehicle. On day 17, punch biopsies were taken from all three lesions and from the perilesional zone of all test sites in order to perform an immunohistochemical investigation, using markers to assess proliferation, differentiation and inflammation.

RESULTS

The SUM score (erythema + induration + scaling) of the lesion treated with dithranol/clobetasol showed a pronounced reduction, which was significantly greater than the SUM score of the lesion treated with dithranol/vehicle. However, the scores of both sites were equal by 6 weeks of follow-up. Comparing the two treated lesions, we observed a lower number of cycling epidermal cells in the dithranol/clobetasol lesion and a significantly lower perivascular dermal score of T lymphocytes. Comparing the perilesional skin of the two treated sites we observed less cycling epidermal cells in the dithranol/clobetasol-treated site. Regarding perilesional differentiation, the interpapillary involucrin expression was higher in the dithranol/clobetasol-treated site. With respect to perilesional inflammation the expression of dermal polymorphonuclear leucocytes, monocytes, macrophages and T lymphocytes in the dermal infiltrate were significantly lower in the dithranol/clobetasol-treated site.

CONCLUSIONS

The addition of clobetasol-17-propionate enhanced the antipsoriatic efficacy of dithranol by interfering with T-cell accumulation and epidermal proliferation. The addition of a corticosteroid reduced perilesional dithranol inflammation at the cellular level, although clinically detectable dithranol erythema was not reduced.

Interleukin 20: discovery, receptor identification, and role in epidermal function

A structural, profile-based algorithm was used to identify interleukin 20 (IL-20), a novel IL-10 homolog. Chromosomal localization of IL-20 led to the discovery of an IL-10 family cytokine cluster. Overexpression of IL-20 in transgenic (TG) mice causes neonatal lethality with skin abnormalities including aberrant epidermal differentiation. Recombinant IL-20 protein stimulates a signal transduction pathway through STAT3 in a keratinocyte cell line, demonstrating a direct action of this ligand. An IL-20 receptor was identified as a heterodimer of two orphan class II cytokine receptor subunits. Both receptor subunits are expressed in skin and are dramatically upregulated in psoriatic skin. Taken together, these results demonstrate a role in epidermal function and psoriasis for IL-20, a novel cytokine identified solely by bioinformatics analysis.