Hsp27 Expression Coincides with Epidermal Stratification during Human Epidermal Morphogenesis

A comprehensive review of treatment options for recalcitrant nongenital cutaneous warts

Introduction: The treatment of recalcitrant nongenital cutaneous warts has always been challenging for dermatologists as they often recur and relapse. Multiple treatment options have been investigated to improve the outcome. This review provides an overview of the current treatment modalities and summarizes the efficacy and side effects of each treatment option for recalcitrant nongenital cutaneous warts.Methods: A PubMed search was performed through July 2019 to include all English language reports investigating the treatment for recalcitrant nongenital cutaneous warts, regardless of design.Results: A total of 144 studies were included in this review. The treatment options for recalcitrant nongenital cutaneous warts can be divided into three groups: destructive treatment, immunotherapy, and cytotoxic agents. Although both destructive therapies and cytotoxic agents demonstrated high complete response rates, immunotherapy, which is a minimally invasive method, was superior in terms of the clearance of distant warts. Intralesional mumps-measles-rubella injections and purified protein derivatives currently demonstrate high efficacy with well-established clinical evidence.Conclusions: Many upcoming treatment modalities, especially immunotherapy, are promising. However, more comparative studies are required to verify the efficacy and safety profile.

Treatment of Recalcitrant Viral Warts with Combination Therapy of Systemic Acitretin and Diphenylcyclopropenone Immunotherapy

Viral warts are benign proliferations of the epithelium caused by human papilloma virus (HPV) infection. Diverse therapeutic options are available for viral warts, depending on extension and severity of the disease. We report a case of a 19-year-old man who presented with multiple viral warts on hands and feet for 5 years. He was treated at other clinics before visiting our hospital, but there was no improvement. We treated the lesions with a combination therapy of systemic acitretin and diphenylcyclopropenone (DPCP) immunotherapy for 6 months. A significant improvement was observed during the 12th week of therapy. Herein, we report a case of recalcitrant viral warts showing complete regression when a combination therapy of oral acitretin and immunotherapy was administered.

Heat shock proteins in the physiology and pathophysiology of epidermal keratinocytes

Heat shock proteins (HSPs), a large group of highly evolutionary conserved proteins, are considered to be main elements of the cellular proteoprotection system. HSPs are encoded by genes activated during the exposure of cells to proteotoxic factors, as well as by genes that are expressed constitutively under physiological conditions. HSPs, having properties of molecular chaperones, are involved in controlling/modulation of multiple cellular and physiological processes. In the presented review, we summarize the current knowledge on HSPs in the biology of epidermis, the outer skin layer composed of stratified squamous epithelium. This tissue has a vital barrier function preventing from dehydratation due to passive diffusion of water out of the skin, and protecting from infection and other environmental insults. We focused on HSPB1 (HSP27), HSPA1 (HSP70), HSPA2, and HSPC (HSP90), because only these HSPs have been studied in the context of physiology and pathophysiology of the epidermis. The analysis of literature data shows that HSPB1 plays a role in the regulation of final steps of keratinization; HSPA1 is involved in the cytoprotection, HSPA2 contributes to the early steps of keratinocyte differentiation, while HSPC is essential in the re-epithelialization process. Since HSPs have diverse functions in various types of somatic tissues, in spite of multiple investigations, open questions still remain about detailed roles of a particular HSP isoform in the biology of epidermal keratinocytes.

Immunolocalization of heat shock proteins 27 and 47 during repair of induced oral ulcers

Heat shock proteins (Hsps) 27 and 47 are involved in the control of apoptosis, cell migration, and collagen synthesis. There is some understanding of the immunolocalization of these proteins during the repair process in skin and gastrointestinal mucosa, but their expressions in normal and injured oral mucosa are unknown. The aim of this study was to analyze the immunolocalization and intensity of these proteins in oral ulcers induced in rats and to compare these expression levels with those reported in skin and gastric mucosa. Ulcers were induced on the ventral surface of the tongues of rats. The rats were then euthanized at 0, 24, 48, 72, and 120 h. Hsp27 expression remained low in the first hours of repair, but was higher at 72 h, mainly in the migrating epithelium. Expression of Hsp47 was high at 48 h, mainly in fibroblasts, cells of the vascular wall, and basal keratinocytes of migrating epithelium. In the control group, expressions of these proteins were low, which indicates that these Hsps are constitutive proteins in oral mucosa. Expression levels were similar to those reported in the healing of skin lesions and gastric ulcer, suggesting a common mechanism of Hsp activation in the repair of these tissues.

Genome-wide analysis and expression profiling of the small heat shock proteins in zebrafish

Small Heat Shock Proteins (sHSPs) have important roles in preventing disease and promoting resistance to environmental stressors. Mutations in any one of a number of sHSPs, including HSP27 (HSPB1), HSP22 (HSPB8), alphaA-crystallin (HSPB4), or alphaB-crystallin (HSPB5) can result in neuronal degeneration, myopathy, and/or cataract in humans. Ten sHSPs are known in humans, and thirteen have been identified in teleost fish. Here we report the identification of thirteen zebrafish sHSPs. Using a combination of phylogenetic analysis and analysis of synteny, we have determined that ten are likely orthologs of human sHSPs. We have used quantitative RT-PCR to determine the relative expression levels of all thirteen sHSPs during development and in response to heat shock. Our findings indicate that most of the zebrafish sHSPs are expressed during development, and five of these genes are transcriptionally upregulated by heat shock at one or more stages of development.

AKT-dependent HspB1 (Hsp27) activity in epidermal differentiation

AKT activity has been reported in the epidermis associated with keratinocyte survival and differentiation. We show in developing skin that Akt activity associates first with post-proliferative, para-basal keratinocytes and later with terminally differentiated keratinocytes that are forming the fetal stratum corneum. In adult epidermis the dominant Akt activity is in these highly differentiated granular keratinocytes, involved in stratum corneum assembly. Stratum corneum is crucial for protective barrier activity, and its formation involves complex and poorly understood processes such as nuclear dissolution, keratin filament aggregation, and assembly of a multiprotein cell cornified envelope. A key protein in these processes is filaggrin. We show that one target of Akt in granular keratinocytes is HspB1 (heat shock protein 27). Loss of epidermal HspB1 caused hyperkeratinization and misprocessing of filaggrin. Akt-mediated HspB1 phosphorylation promotes a transient interaction with filaggrin and intracellular redistribution of HspB1. This is the first demonstration of a specific interaction between HspB1 and a stratum corneum protein and indicates that HspB1 has chaperone activity during stratum corneum formation. This work demonstrates a new role for Akt in epidermis.

Reduced expression of the antiapoptotic proteins of Bcl-2 gene family in the lesional epidermis of patients with Darier's disease

BACKGROUND

Dyskeratotic cells in Darier's disease (DD) are thought to represent apoptotic keratinocytes. Bcl-2 gene family proteins play a major role in the regulation of apoptosis of epidermal keratinocytes and reveal pleiotropic interactions with intracellular Ca2+ homeostasis. The latter is impaired in DD because of mutations of ATP2A2 gene that encodes the type 2 isoforms of the sarcoplasmic/endoplasmic reticulum (ER) Ca++ ATPase 2 (SERCA2) pump.

METHODS

The expression of Bcl-2, Bax, and Bcl-x(L) proteins was investigated in the epidermis of 11 patients with DD and of 11 sex- and age-matched healthy controls by immunohistochemistry.

RESULTS

The expression of Bcl-2 and Bcl-xL was clearly reduced in the lesional epidermis of the patients, as compared with the normal epidermis of healthy controls, whereas the expression of Bax remained unaltered.

CONCLUSIONS

The alterations in the expression of Bcl-2 gene family proteins could be a crucial event for the activation of the apoptotic process in the lesional epidermis of DD patients and for the occurrence of the characteristic dyskeratotic keratinocytes. The question as to whether these alterations are associated with the ER Ca2+ depletion in DD or represent secondary phenomena unrelated to the genetic defect of this genodermatosis remains to be elucidated.