H.-S. Yu

FK506 promotes melanocyte and melanoblast growth and creates a favourable milieu for cell migration via keratinocytes: possible mechanisms of how tacrolimus ointment induces repigmentation in patients with vitiligo

Background  Vitiligo is an acquired pigmentary disorder characterized by depigmentation of skin and hair. As the pathogenesis of this disease is still obscure, the treatment of vitiligo has generally been unsatisfactory and often disappointing. Topical tacrolimus (FK506) ointment has recently been added to the armamentarium against this pigmentary disorder. Despite its clinical efficacy, the underlying mechanisms of how topical tacrolimus induces repigmentation in vitiligo have rarely been investigated. As tacrolimus ointment is applied directly to the skin, its impact on keratinocytes (KCs) requires thorough investigation.

CXC chemokine receptor CXCR4 expression enhances tumorigenesis and angiogenesis of basal cell carcinoma

Background  Chemokines and their receptors, well known for their ability to attract leucocytes, also play important roles for tumour progression.

Effects of psoralen plus ultraviolet A irradiation on cultured epidermal cells in vitro and patients with vitiligo in vivo

Background  Both psoralen plus ultraviolet (UV) A (PUVA) and narrowband UVB (NB‐UVB) irradiation are effective treatments for vitiligo vulgaris. However, the mechanisms of PUVA and NB‐UVB in repigmentation are not thoroughly clarified. Our previous results showed that NB‐UVB irradiation directly promotes melanocyte (MC) migration and stimulates MC proliferation via keratinocytes (KCs).

Lifetime exposure to cigarette smoking and the development of adult-onset atopic dermatitis

Background  Adult‐onset atopic dermatitis (AD) has recently been recognized as a distinct disease entity, but its risk factors have not yet been clearly defined. Although gestational and perinatal exposure to tobacco smoking may be associated with the development of classic AD, the association between active/passive smoking and adult‐onset AD remains controversial.

FK506 independently upregulates transforming growth factor β and downregulates inducible nitric oxide synthase in cultured human keratinocytes: possible mechanisms of how tacrolimus ointment interacts with atopic skin

Background  Tacrolimus ointment (FK506) has been used in recent years for the treatment of atopic dermatitis (AD), with favourable results. Most of the therapeutic efficacy of FK506 in AD has been attributed to its immunomodulatory effects on different immune cell types, but its effects on keratinocytes (KCs) have rarely been discussed. Studies have shown that low expression of transforming growth factor (TGF)‐β and high expression of nitric oxide synthase (NOS) are implicated in the pathogenesis of AD.

Mechanistic correlations between two itch biomarkers, cytokine interleukin-31 and neuropeptide β-endorphin, via STAT3/calcium axis in atopic dermatitis.

Summary Background  Itch is the cardinal symptom of atopic dermatitis (AD). β‐Endorphin, a neuropeptide, is increased in both AD skin and sera. Interleukin (IL)‐31, an itch‐relevant cytokine, activates IL‐31 receptors in keratinocytes. However, how IL‐31 and β‐endorphin interact in AD skin remains elusive.

Distinct SPINK5 and IL‐31 polymorphisms are associated with atopic eczema and non‐atopic hand dermatitis in Taiwanese nursing population

Abstract:  The term ‘hand dermatitis’ describes inflammatory skin condition localized to the hands. Nurses working at hospital settings are prone to develop hand dermatitis. The current study aimed to evaluate whether certain genetic polymorphisms were associated with the development of atopic eczema or non‐atopic hand dermatitis in Taiwanese population. Nurses of Kaohsiung Medical University Hospital were recruited. Atopic eczema, non‐atopic hand dermatitis and normal control groups were identified. The serine protease inhibitor Kazal type 5 (SPINK5), filaggrin and interleukin‐31 (IL‐31) gene variants were compared between the diseased and control groups. Our results showed that rs2303070 T allele of SPINK5 (assuming recessive model; OR = 3.58, 95% CI 1.63–7.84; P = 0.0014) and rs7977932 G allele of IL‐31 (assuming recessive model; OR = 18.25, 95% CI = 3.27–101.94; P = 0.0009) were associated with increased risks of developing atopic eczema, while rs6892205 G allele of SPINK5 (assuming dominant model; OR = 3.79, 95% CI 1.55–9.28; P = 0.0036) was associated with the development of non‐atopic hand dermatitis. In summary, our results showed that distinct SPINK5 and IL‐31 gene variants were associated with the development of atopic eczema and non‐atopic hand dermatitis. The barrier function, particularly those regulated by SPINK5, may play an important role in the development of both atopic eczema and non‐atopic hand dermatitis.

Hand dermatitis among university hospital nursing staff with or without atopic eczema: assessment of risk factors.

Background. Nurses are prone to develop hand dermatitis. Although an atopic constitution has been identified as a genetic risk factor, the behavioural risk factors associated with hand dermatitis in wet work conditions have not been fully explored.

Low-energy helium-neon laser induces melanocyte proliferation via interaction with type IV collagen: visible light as a therapeutic option for vitiligo.

Background  The treatment of vitiligo remains a challenge for clinical dermatologists. We have previously shown that the helium–neon laser (He–Ne laser, 632·8 nm) is a therapeutic option for treatment of this depigmentary disorder.

Androgen receptor-mediated apoptosis in bovine testicular induced pluripotent stem cells in response to phthalate esters.

The androgen receptor (AR) has a critical role in promoting androgen-dependent and -independent apoptosis in testicular cells. However, the molecular mechanisms that underlie the ligand-independent apoptosis, including the activity of AR in testicular stem cells, are not completely understood. In the present study, we generated induced pluripotent stem cells (iPSCs) from bovine testicular cells by electroporation of octamer-binding transcription factor 4 (OCT4). The cells were supplemented with leukemia inhibitory factor and bone morphogenetic protein 4, which maintained and stabilized the expression of stemness genes and pluripotency. The iPSCs were used to assess the apoptosis activity following exposure to phthalate esters, including di (2-ethyhexyl) phthalates, di (n-butyl) phthalate, and butyl benzyl phthalate. Phthalate esters significantly reduced the expression of AR in iPSCs and induced a higher ratio of BAX/BCL-2, thereby favoring apoptosis. Phthalate esters also increased the expression of cyclin-dependent kinase inhibitor 1 (p21Cip1) in a p53-dependent manner and enhanced the transcriptional activity of p53. The forced expression of AR and knockdown of p21Cip1 led to the rescue of the phthalate-mediated apoptosis. Overall, this study suggests that testicular iPSCs are a useful system for screening the toxicity of environmental disruptors and examining their effect on the maintenance of stemness and pluripotency, as well as for identifying the iPSC signaling pathway(s) that are deregulated by these chemicals.