The protective effects of ultraviolet A1 irradiation on spontaneous lupus erythematosus-like skin lesions in MRL/lpr mice

Requisite instruments for the establishment of three-dimensional epidermal human skin equivalents-A methods review

Human skin equivalents (HSEs) are three-dimensional skin organ culture models raised in vitro. This review gives an overview of common techniques for setting up HSEs. The HSE consists of an artificial dermis and epidermis. 3T3-J2 murine fibroblasts, purchased human fibroblasts or freshly isolated and cultured fibroblasts, together with other components, for example, collagen type I, are used to build the scaffold. Freshly isolated and cultured keratinocytes are seeded on top. It is possible to add other cell types, for example, melanocytes, to the HSE-depending on the research question. After several days and further steps, the 3D skin can be harvested. Additionally, we show possible markers and techniques for evaluation of artificial skin. Furthermore, we provide a comparison of HSEs to human skin organ culture, a model which employs human donor skin. We outline advantages and limitations of both models and discuss future perspectives in using HSEs.

Severe Herpes Zoster Secondary to Systemic Lupus Erythematosus Successfully Treated with Ultraviolet A1 Phototherapy: A Case Report

Background: The incidence of herpes zoster (HZ) in systemic lupus erythematosus (SLE) patients is high, and the symptoms are usually severe and resistant to treatment, and the prognosis is poor. Ultraviolet (UV) A1 is a band of UV light, and UVA1 phototherapy has been widely used to treat various inflammatory skin diseases. Objective: At present, UVA1 has been considered as a potential adjuvant therapy for HZ in SLE patients. To the best of our knowledge, this is the first case report concerning the successful application of UVA1 in the treatment of HZ secondary to SLE. Methods: In this article, a clinical case report is presented, wherein the patient did not respond to conventional treatment, but was markedly responsive to the treatment of UVA1 phototherapy, and well tolerated. Results: A 29-year-old woman with severe HZ secondary to SLE was successfully treated with UVA1 phototherapy. Conclusions: UVA1 phototherapy can be used as an effective adjuvant treatment for HZ secondary to SLE.

Ultraviolet A-1 in Dermatological Diseases

The exposure to ultraviolet radiations and visible light, or phototherapy, is a well-known therapeutic tool available for the treatment of many dermatological disorders. The continuos medical and technological progresses, of the last 50 years, have involved the field of phototherapy, which evolved from UVA and PUVA in its various forms, to the development of narrowband UVB (NB-UVB) and NB-UVB micro-focused phototherapies. Further advances in technology have now permitted the introduction of a new device emitting UVA-1 radiations.

The safety and efficacy of light emitting diodes-based ultraviolet A1 phototherapy in bleomycin-induced scleroderma in mice

PURPOSE

To define the efficacy and safety of narrowband ultraviolet A1 (UVA1) for the treatment of dermal fibrosis in bleomycin-induced mouse model of scleroderma.

MATERIALS AND METHODS

42 DBA/2 strain mice were included in the study: healthy mice and mice with established scleroderma, treated with high or medium dose of UVA1. Non-treated groups served as control. The equipment emitting 365±5nm UVA1 radiation was used in the study. The average cumulative doses were 1200J/cm² for high and 600J/cm² for medium dose course. Histological analysis was performed for the evaluation of the dermal thickness and mast cells density. The expressions of p53 and Ki-67 proteins were assessed by immunohistochemical analyses.

RESULTS

Skin thickness of mice with scleroderma, treated with high and medium dose of UVA1, were lower (272.9±113.2μm and 394±125.9μm, respectively) in comparison to the dermal thickness of non-treated animals (599±55.7μm). The dermal mast cells count in mice with scleroderma was reduced after high and medium dose treatment to 11±1.7 and 13±2.2, respectively, as compared to that in non-treated mice (23±3.0). No significant upregulation of p53 nor Ki-67 proteins was observed in the skin of healthy mice and mice with scleroderma after high- and medium-dose of UVA1.

CONCLUSIONS

The results of this study indicate that 365nm UVA1 with the cumulative doses of 1200J/cm² and 600J/cm² is safe and effective for the dermal fibrosis treatment.

Severer lupus erythematosus-like skin lesions in MRL/lpr mice with homozygous Kitwsh/wsh mutation

OBJECTIVE

To clarify the roles of mast cells (MCs) on the pathogenesis of lupus erythematosus (LE)-like skin lesions on MRL/lpr mice.

METHODS

MRL/lpr mice were mated with C57BL/6-Kit^wsh/wsh mice and the heterozygous F1 mice were 10 times backcrossed with the parental MRL/lpr to generate MRL/lpr-Kit^wsh/wsh mice. MC-deficient MRL/lpr-Kit^wsh/wsh mice were compared with MRL/lpr-Kit^+/+ and MRL/lpr-Kit^wsh/+ mice with intact MCs.

RESULTS

MRL/lpr-Kit^wsh/wsh mice developed skin lesions without infiltrating MCs. As similar skin lesions on MRL/lpr-Kit^+/+ mice and MRL/lpr-Kit^wsh/+ mice contain comparable number of MCs, these mice were collectively analyzed as MRL/lpr mice with MCs. Compared with MRL/lpr mice with MCs, skin lesions developed earlier and showed consistently higher severity, with significantly higher mRNA expressions of many inflammatory cytokines in the dorsal skin on MRL/lpr mice without MCs. Furthermore, survival rate was significantly lower in MRL/lpr mice without MCs. The number of infiltrating MCs significantly increased in association with the severity of skin lesions in MRL/lpr mice with MCs.

CONCLUSIONS

These results demonstrated that MCs are infiltrated to suppress the progression of LE-like skin lesions in MRL/lpr mice.

The effect of hydroxychloroquine on lupus erythematosus-like skin lesions in MRL/lpr mice

OBJECTIVES

To evaluate the effect and safety of hydroxychloroquine (HCQ) on lupus erythematosus (LE)-like skin lesions in the MRL/lpr mouse, a model for systemic LE (SLE).

METHODS

We divided the MRL/lpr mice into three groups that were given: (1) drinking water, (2) HCQ at a dose of 4 mg/kg/d, or (3) HCQ at a dose of 40 mg/kg/d. The HCQ was administered to examine the effect and safety of HCQ on skin lesions and the number of infiltrating cells including mast cells in the dermis.

RESULTS

Six of 13 mice in the group given drinking water, 3 of 11 mice in the group administered low-dose HCQ (4 mg/kg/d), and 1 of 10 mice in the group administered high-dose HCQ (40 mg/kg/d) presented the skin lesions. The average number of mast cells was 81, 50, and 12 (magnification, ×100), the mortality rate was 24%, 8%, and 9% and the mean body weight gain was 4.6 g, 8.0 g and 5.1 g, respectively.

CONCLUSIONS

HCQ was demonstrated to decrease the appearance of LE-like lesions and the number of mast cells in the dermis. Furthermore, there were no obvious systemic adverse effects. This study provides evidence that suggests benefits in human patients.

Caffeine promotes anti-tumor immune response during tumor initiation: Involvement of the adenosine A2A receptor

Epidemiologic studies depict a negative correlation between caffeine consumption and incidence of tumors in humans. The main pharmacological effects of caffeine are mediated by antagonism of the adenosine receptor, A2AR. Here, we examine whether the targeting of A2AR by caffeine plays a role in anti-tumor immunity. In particular, the effects of caffeine are studied in wild-type and A2AR knockout (A2AR(-/-)) mice. Tumor induction was achieved using the carcinogen 3-methylcholanthrene (3-MCA). Alternatively, tumor cells, comprised of 3-MCA-induced transformed cells or B16 melanoma cells, were inoculated into animal footpads. Cytokine release was determined in a mixed lymphocyte tumor reaction (MLTR). According to our findings, caffeine-consuming mice (0.1% in water) developed tumors at a lower rate compared to water-consuming mice (14% vs. 53%, respectively, p=0.0286, n=15/group). Within the caffeine-consuming mice, tumor-free mice displayed signs of autoimmune alopecia and pronounced leukocyte recruitment intocarcinogen injection sites. Similarly, A2AR(-/-) mice exhibited reduced rates of 3-MCA-induced tumors. In tumor inoculation studies, caffeine treatment resulted in inhibition of tumor growth and elevation in proinflammatory cytokine release over water-consuming mice, as depicted by MLTR. Addition of the adenosine receptor agonist, NECA, to MLTR resulted in a sharp decrease in IFNγ levels; this was reversed by the highly selective A2AR antagonist, ZM241385. Thus, immune response modulation through either caffeine or genetic deletion of A2AR leads to a Th1 immune profile and suppression of carcinogen-induced tumorigenesis. Taken together, our data suggest that the use of pharmacologic A2AR antagonists may hold therapeutic potential in diminishing the rate of cancer development.

A comparative study of UV-induced cell signalling pathways in human keratinocyte-derived cell lines

Ultraviolet (UV) radiation can activate the p38 mitogen-activated protein kinase (MAPK), Jun N-terminal kinase (JNK) and nuclear factor-κB (NFκB) pathways in skin cells. HaCaT cells are widely used as a primary keratinocyte substitute to study these pathways. However, like most squamous cell carcinomas (SCCs), it contains a dysfunctional p53. It is unclear if HaCaT cells activate these signalling pathways similarly to SCC cells (Colo16) or to primary human epidermal keratinocytes (HEK). In this study, the UV activation (UVA, UVB, UVA+B, UVB+A) of p38 MAPK, JNK and NFκB pathways, and TNFα secretion by HEK, HaCaT and Colo16 cells were investigated. The signalling pathway activation was UV-type and dose-dependent with UVB+A radiation inducing a high p38 and JNK activation. HaCaT cells exhibited 2- to 4-fold higher activity of the p38 (771% at 60 min) and JNK (794% at 30 min) pathways following UVB+A radiation than did HEK cells (p38: 367% at 15 min and JNK: 184% at 30 min). While both HaCaT and Colo16 cells did not activate the NFκB pathway, Colo16 cells had a lower p38 and higher JNK activity than HaCaT cells. Irradiated HaCaT cells produced less TNFα (UVB: 3.5 pg/ml), while HEK cells produced the most (UVB: 1,296 pg/ml). When co-exposed to IL1α, irradiated HaCaT had the greatest fold of TNFα release (UVB: 16.2-fold, UVA+B: 8.9-fold and UVB+A: 6.1-fold). The pattern of activation and TNFα secretion of HaCaT cells mirrored that of Colo16 cells. It is likely that the presence of molecular alterations in HaCaT cells may be responsible for its different responses to that seen for HEK cells. The results of this study suggest caution in using HaCaT cells as a substitute for normal keratinocytes in investigating UV-induced cells signalling pathways.

UVB-stimulated TNFα release from human melanocyte and melanoma cells is mediated by p38 MAPK

Ultraviolet (UV) radiation activates cell signaling pathways in melanocytes. As a result of altered signaling pathways and UV-induced cellular damage, melanocytes can undergo oncogenesis and develop into melanomas. In this study, we investigated the effect of UV-radiation on p38 MAPK (mitogen-activated protein kinase), JNK and NFκB pathways to determine which plays a major role in stimulating TNFα secretion in human HEM (melanocytes) and MM96L (melanoma) cells. MM96L cells exhibited 3.5-fold higher p38 activity than HEM cells at 5 min following UVA + B radiation and 1.6-fold higher JNK activity at 15–30 min following UVB+A radiation, while NFκB was minimally activated in both cells. Irradiated HEM cells had the greatest fold of TNFα secretion (UVB: 109-fold, UVA + B: 103-fold & UVB+A: 130-fold) when co-exposed to IL1α. The p38 inhibitor, SB202190, inhibited TNFα release by 93% from UVB-irradiated HEM cells. In the UVB-irradiated MM96L cells, both SB202190 and sulfasalazine (NFκB inhibitor) inhibited TNFα release by 52%. Although, anisomycin was a p38 MAPK activator, it inhibited TNFα release in UV-irradiated cells. This suggests that UV-mediated TNFα release may occur via different p38 pathway intermediates compared to those stimulated by anisomycin. As such, further studies into the functional role p38 MAPK plays in regulating TNFα release in UV-irradiated melanocyte-derived cells are warranted.

Photosensitivity in cutaneous lupus erythematosus

BACKGROUND

Ultraviolet radiation (UVR) is a well-known exacerbating factor for cutaneous lupus erythematosus (CLE), with photosensitivity comprising one of the American College of Rheumatology (ACR) diagnostic criteria for systemic lupus erythematosus (SLE). However, discerning true photosensitivity in this population is difficult due to the broad language utilized by the ACR and the delayed-onset nature of photosensitive lupus lesions.

AIMS

The objective of this report is to provide a review of photosensitivity, photoprovocation, and phototherapy in the context of CLE patients.

METHODS

A literature review in PubMed was conducted using the terms 'ultraviolet light,' 'lupus erythematosus,' 'photoprovocation,' or 'photosensitivity.'

RESULTS

Self-patient reporting of photosensitivity and the broad definition of photosensitivity have led to the wide range of photosensitivity rates in CLE patients. Photoprovocation testing provides a more objective method to measure photosensitivity, but even these trials demonstrate significant differences due to protocol variations. Despite UVR's deleterious effect on lupus patients, ultraviolet A (UVA)-1 may have therapeutic benefits as shown by observations on murine models and human lupus subjects.

CONCLUSIONS

Accurately discerning photosensitivity has diagnostic implications for SLE and provides motivation for greater patient adherence to photoprotective methods.

Mast cell mediators in tolerance

Our knowledge on the function of mast cells (MC) as part of the immune system has expanded from 'key cells in mediating allergy' to 'tunable regulators of the immune response'. Over the past years however, a large body of evidence has been presented indicating a more regulatory role for MC in the immune system by both contact dependent and independent mechanisms. Considering the vast amount of soluble mediators released by MC, it is not surprising that some are involved in the maintenance of peripheral tolerance and the control or even help to resolve ongoing inflammation. In this review we will focus on the immunosuppressive function of some of these mediators produced by MC in a wide variety of disease models.

[Pathogenesis of cutaneous lupus erythematosus from LE-prone mice]

Mouse models are similar but not identical to human diseases. However, they are important for research into the pathogenesis underlying autoimmune diseases because they allow us to evaluate similarities and differences between human diseases and mouse models. There are many inbred strains of systemic lupus erythematosus (SLE)-prone mice including New Zealand Black (NZB), F1 hybrids of NZB x New Zealand White (NZW) (B/W F1), MRL/Mp-lpr/lpr (MRL/lpr), and BXSB mice. The postulated etiology of these murine diseases includes many genetic and extrinsic factors such as retroviruses, an impaired balance of T cell interaction, ultraviolet irradiation, etc. For examples, genetic studies of MRL/lpr mice revealed that the appearance of macroscopic LE-like skin lesions needs the lpr mutation plus an additional factor in an autosomal dominant fashion. The candidate is ultraviolet (UV) B light, the susceptibility to which is regulated by the genetic background. Such abnormalities described in SLE now span the spectrum from innate immunity to acquired immunity. In this review, based on historical review, we focus on skin lesions from the well-studied MRL/lpr and B/W F1 mouse and discuss how SLE-prone mice can contribute to a better understanding of cutaneous LE pathogenesis.