Clinical Manifestation of Alopecia Areata After COVID-19 Infection or Vaccination.

Background: Alopecia areata (AA) is characterized by an autoimmune inflammatory response to hair follicles. Several studies have suggested that infection and vaccination can trigger an autoimmune process around hair follicles. Moreover, reports of AA and various other autoimmune diseases have increased since the coronavirus disease 2019 (COVID-19) pandemic became established.

SIRT1 downregulation provokes immune-inflammatory responses in hair follicle outer root sheath cells and may contribute to development of alopecia areata.

Background: Silent information regulator 1 (SIRT1), a type III histone deacetylase, is involved in various cutaneous and systemic autoimmune diseases including systemic lupus erythematosus, rheumatoid arthritis, and psoriasis. However, little is known about the role of SIRT1 in the development of alopecia areata (AA).

Objectives: This study investigated whether SIRT1 regulates the hair follicle immune system and is involved in AA pathogenesis.

Krüppel-like factor 4 (KLF4) facilitates lipid production in immortalized human sebocytes via regulating the expression of SREBP1.

Background: Acne is associated with the excessive production of sebum, a complex mixture of lipids, in the sebaceous glands. The transcription factor Krüppel-like factor 4 (KLF4) plays an important role in skin morphogenesis, but its role in sebum production by sebocytes is not well known.

Purpose: In this study, we investigated the possible action mechanism of KLF4 during calcium-induced lipogenesis in immortalized human sebocytes.

Pitavastatin Induces Apoptosis of Cutaneous Squamous Cell Carcinoma Cells through Geranylgeranyl Pyrophosphate-Dependent c-Jun N-Terminal Kinase Activation.

Background: Pitavastatin is a cholesterol-lowering drug and is widely used clinically. In addition to this effect, pitavastatin has shown the potential to induce apoptosis in cutaneous squamous cell carcinoma (SCC) cells.

Objective: The purpose of this study is to investigate the effects and possible action mechanisms of pitavastatin.

Screening of Plant-Derived Natural Extracts to Identify a Candidate Extract Capable of Enhancing Lipid Synthesis in Keratinocytes.

Background: Reduced lipid content in the stratum corneum is a major cause of skin-barrier dysfunction in various pathological conditions. Promoting lipid production is a potential strategy to improve skin-barrier function. Recent evidence supports the beneficial effects of adiponectin on lipid metabolism and senescence in keratinocytes.

Augmentation of NAD by Dunnione Ameliorates Imiquimod-Induced Psoriasis-Like Dermatitis in Mice.

Background: Dunnione has anti-inflammatory properties arising from its ability to alter the ratio of NAD/NADH through NAD(P)H quinone oxidoreductase 1 (NQO1) enzymatic action, followed by subsequent inhibition of NF-κB and inflammatory cytokines. Psoriasis is a chronic, inflammatory skin disorder in which the IL-23/Th17 axis plays an important role in inflammation. However, it is unclear whether modulation of NAD levels affects psoriasis, such as skin inflammation.

Role of Substance P in Regulating Micro-Milieu of Inflammation in Alopecia Areata.

Background: Alopecia areata (AA) is an autoimmune disease characterized by chronic inflammation, the pathogenesis of which is unknown. Stress is believed to play a role; however, evidence remains insufficient. A recent study showed that substance P (SP) damaged hair follicles by causing neurogenic inflammation, activating perifollicular mast cells, and inducing keratinocyte apoptosis.

The potential role of fibroblast-derived multi-peptide factors in activation of growth factors and β-Catenin in hair follicle cells.

Background: Dermal fibroblasts play a pivotal role in hair follicle regeneration during wound repair. Recently, dermal fibroblast-conditioned medium (DFCM), which contains multi-peptide factors (MPFs), has been used to promote wound repair.

Aim: This study aimed to investigate the stimulatory effects of MPF-containing DFCM on hair growth.

Inhibitory Effect of Mitoxantrone on Collagen Synthesis in Dermal Fibroblasts.

Background: Fibroblasts produce collagen molecules that support the structure of the skin. The decrease and hypersynthesis of collagen causes skin problems such as skin atrophy, wrinkles and scars.

Objective: The purpose of this study is to investigate the mechanism of mitoxantrone on collagen synthesis in fibroblasts.

Activation of NLRP3 Inflammasome by Palmitic Acid in Human Sebocytes.

Background: Sebocytes are the main cells involved in the pathogenesis of acne by producing lipids and inflammatory cytokines. Although palmitic acid (PA) has been suggested to induce an inflammatory reaction, its effect on sebocytes remains to be elucidated.

Objective: In the present study, we investigated whether PA promotes inflammasome-mediated inflammation of sebocytes both and .

Potential Role of Cytosolic RNA Sensor as an Inhibitor for Keratinocyte Differentiation in the Pathogenesis of Psoriasis.

Background: Psoriasis is a chronic inflammatory skin disease. The etiology of psoriasis is not fully understood, but the genetic background is considered to be the most important factor. To date, many psoriasis-related genes have been discovered, but the role of many important genes has not been well understood.

Possible Role of Lysine Demethylase 2A in the Pathophysiology of Psoriasis.

Background: Psoriasis is a common chronic inflammatory skin disease. The development of psoriasis is dependent on many intercellular events such as innate immunity and T cell-mediated inflammation. Furthermore, genetic factors are strongly implicated in the pathophysiology of psoriasis.

Sorafenib induces pigmentation via the regulation of β-catenin signalling pathway in melanoma cells.

We conducted large-scale screening test on drugs that were already approved for other diseases to find pigmentation-modulating agents. Among drugs with potential for pigmentation control, we selected sorafenib and further investigated the effect on pigmentation using HM3KO melanoma cells. As a result of treating melanoma cells with sorafenib, pigmentation was promoted in terms of melanin content and tyrosinase activity.

Deficiency of Crif1 in hair follicle stem cells retards hair growth cycle in adult mice.

Hair growth is the cyclically regulated process that is characterized by growing phase (anagen), regression phase (catagen) and resting phase (telogen). Hair follicle stem cells (HFSCs) play pivotal role in the control of hair growth cycle. It has been notified that stem cells have the distinguished metabolic signature compared to differentiated cells, such as the preference to glycolysis rather than mitochondrial respiration.

Tumor Suppressive Function of NQO1 in Cutaneous Squamous Cell Carcinoma (SCC) Cells.

Cutaneous squamous cell carcinoma (SCC) is a common cancer that significantly decreases the quality of life. It is known that external stimulus such as ultraviolet (UV) radiation induces cutaneous SCC via provoking oxidative stress. NAD(P)H dehydrogenase 1 (NQO1) is a ubiquitous flavoenzyme that functions as a guardian against oxidative stress.

Clinical Relevance for Serum Cold-Inducible RNA-Binding Protein Level in Alopecia Areata.

Background: Alopecia areata (AA), a chronic, relapsing hair-loss disorder, is considered to be a T-cell-mediated autoimmune disease. Cold-inducible RNA-binding protein (CIRP) belongs to a family of cold-shock proteins that respond to cold stress, and has been identified as a damage-associated molecular pattern (DAMP) molecule that triggers the inflammatory response. Recent studies have shown that high-mobility group box 1, another DAMP molecule, is elevated in serum and scalp tissue of AA patients, suggesting a relationship between DAMP molecules and the pathogenesis of AA.

KLF4 suppresses the tumor activity of cutaneous squamous cell carcinoma (SCC) cells via the regulation of SMAD signaling and SOX2 expression.

Kruppel-like factor 4 (KLF4) is a zinc-finger transcription factor that plays a role in terminal differentiation of epidermal keratinocytes. There are conflicting reports regarding the role of KLF4 in tumor development, with both the tumor suppressive and/or oncogenic properties depending on different conditions and cell types. In this study, we investigated the functional importance of KLF4 in cutaneous squamous cell carcinoma (SCC).

Adiponectin Attenuates the Inflammation in Atopic Dermatitis-Like Reconstructed Human Epidermis.

Background: Atopic dermatitis (AD) is a chronic disorder, with a vicious cycle of repetitive inflammation and deterioration of the epidermal barrier function. Adiponectin, an adipokine, has anti-inflammatory effects on various metabolic and inflammatory disorders. Recently, its level was found to be reduced in serum and tissue samples from AD patients.

Erratum: Possible Role of Single Stranded DNA Binding Protein 3 on Skin Hydration by Regulating Epidermal Differentiation.

[This corrects the article on p. 432 in vol. 30, PMID: 30065583.

Adiponectin Enhances Human Keratinocyte Lipid Synthesis via SIRT1 and Nuclear Hormone Receptor Signaling.

Adiponectin is known to have beneficial effects on lipid and insulin metabolism, wound healing, and cellular senescence, but its effect on skin barrier formation remains unknown. We investigated the effects of adiponectin on keratinocyte lipid synthesis with respect to skin barrier function. Lipid staining revealed an adiponectin-mediated increase in keratinocyte intracellular and reconstructed epidermal lipid content.