Gut microbe-skin axis on a chip for reproducing the inflammatory crosstalk.

The gut-skin axis has emerged as a crucial mediator of skin diseases, with mounting evidence highlighting the influence of gut microbiota on skin health. However, investigating these mechanisms has been hindered by the lack of experimental systems that enable direct study of gut microbiota-skin interactions. Here, we present the gut microbe-skin chip (GMS chip), a novel microfluidic platform designed to model microbiome-gut-skin axis interactions.

Activation of mitochondrial aldehyde dehydrogenase 2 promotes hair growth in human hair follicles.

Introduction: Hair loss is a common phenomenon associated with various environmental and genetic factors. Mitochondrial dysfunction-induced oxidative stress has been recognized as a crucial determinant of hair follicle (HF) biology. Aldehyde dehydrogenase 2 (ALDH2) mitigates oxidative stress by detoxifying acetaldehyde.

Dissolving Candlelit Microneedle for Chronic Inflammatory Skin Diseases.

Chronic inflammatory skin diseases (CISDs) negatively impact a large number of patients. Injection of triamcinolone acetonide (TA), an anti-inflammatory steroid drug, directly into the dermis of diseased skin using needle-syringe systems is a long-established procedure for treating recalcitrant lichenified lesions of CISDs, referred to as TA intralesional injection (TAILI). However, TAILI causes severe pain, causing patients to be stressed and reluctant to undergo treatment.

High-Dose Steroid Dissolving Microneedle for Relieving Atopic Dermatitis.

Dissolving microneedles (DMN) supplemented with therapeutic molecules have been developed to enhance transdermal delivery efficiency of topically applied drugs in a minimally invasive manner. However, the dose of the drugs in DMN system is limited owing to the low solubility of drug. In fact, although triamcinolone acetonide (TA) is one of the most widely prescribed drugs for relieving atopic dermatitis (AD), its poor dissolving nature makes it difficult to design and fabricate DMN containing therapeutic dosage of TA.

"Two-Cell Assemblage" Assay: A Simple Method for Screening Hair Growth-Promoting Compounds.

Alopecia arises due to inadequate hair follicle (HF) stem cell activation or proliferation, resulting in prolongation of the telogen phase of the hair cycle. Increasing therapeutic and cosmetic demand for alleviating alopecia has driven research toward the discovery or synthesis of novel compounds that can promote hair growth by inducing HF stem cell activation or proliferation and initiating the anagen phase. Although several methods for evaluating the hair growth-promoting effects of candidate compounds are being used, most of these methods are difficult to use for large scale simultaneous screening of various compounds.

Shikimic acid, a mannose bioisostere, promotes hair growth with the induction of anagen hair cycle.

Shikimic acid (SA) has recently been found to be a major component of plant stem cells. The exact effects of SA on human hair follicles (HFs) is unknown. The purpose of this study was to examine the effects of SA on hair growth.

Priming mobilization of hair follicle stem cells triggers permanent loss of regeneration after alkylating chemotherapy.

The maintenance of genetic integrity is critical for stem cells to ensure homeostasis and regeneration. Little is known about how adult stem cells respond to irreversible DNA damage, resulting in loss of regeneration in humans. Here, we establish a permanent regeneration loss model using cycling human hair follicles treated with alkylating agents: busulfan followed by cyclophosphamide.

UVB-induced depletion of donor-derived dendritic cells prevents allograft rejection of immune-privileged hair follicles in humanized mice.

Dendritic cells (DCs) are key targets for immunity and tolerance induction; they present donor antigens to recipient T cells by donor- and recipient-derived pathways. Donor-derived DCs, which are critical during the acute posttransplant period, can be depleted in graft tissue by forced migration via ultraviolet B light (UVB) irradiation. Here, we investigated the tolerogenic potential of donor-derived DC depletion through in vivo and ex vivo UVB preirradiation (UV) combined with the injection of anti-CD154 antibody (Ab) into recipients in an MHC-mismatched hair follicle (HF) allograft model in humanized mice.

Novel effect of sildenafil on hair growth.

Background: Sildenafil, a phosphodiesterase 5 (PDE5) inhibitor, is known to increase the intracellular level of cyclic guanosine monophosphate (cGMP), which causes vasodilation. However, the effect of sildenafil on human hair follicles (hHFs) is unknown.

Objective: The purpose of this study was to determine the role of sildenafil in hair growth.

Minoxidil activates β-catenin pathway in human dermal papilla cells: a possible explanation for its anagen prolongation effect.

Background: It is believed that the length of the actively growing phase of the anagen hair cycle mainly contributes to hair length. Recent studies showed that maintenance of β-catenin activity in the dermal papilla cells (DPCs) enables hair follicles to keep actively growing. Topical minoxidil treatment promotes hair growth in men with androgenetic alopecia, suggesting that minoxidil may prolong the actively growing phase of the anagen hair cycle.

Erythropoietin promotes hair shaft growth in cultured human hair follicles and modulates hair growth in mice.

Background: Recent studies have shown that erythropoietin (EPO)/erythropoietin receptor (EPOR) signaling exist in both human and mouse hair follicles (HFs).

Objective: To investigate whether dermal papilla cells (DPCs) express functional EPOR and, if so, to investigate effects of EPO on hair shaft growth in cultured human scalp hair follicles and hair growth in mice.

Methods: EPOR expression in DPCs and follicular keratinocytes was examined by RT-PCR and immunoblot.

Identification of transcriptional targets of Wnt/beta-catenin signaling in dermal papilla cells of human scalp hair follicles: EP2 is a novel transcriptional target of Wnt3a.

Background: Recent studies showed that Wnt signaling through the beta-catenin pathway (canonical Wnt signaling) act on mouse dermal papilla cells (DPCs) enabling hair follicles to keep growing.

Objective: To investigate whether human DPCs respond to canonical Wnt signaling and, if so, to identify target genes of Wnt/beta-catenin pathway.

Methods: Cultured human DPCs were transiently transfected with the beta-catenin responsive TCF reporter plasmid (pTopflash) and corresponding negative control reporter (pFopflash) to assess the activity of beta-catenin signaling by Wnt3a (one of the canonical Wnts).

Synthesis and biological activity of 5-{4-[2-(methyl-p-substituted phenylamino)ethoxy]benzyl}thiazolidine-2,4-diones.

Thiazolidinedione derivatives are potential antidiabetic drugs that bind and activate peroxisome proliferator activated receptor gamma (PPARgamma), which is a member of the nuclear hormone receptor superfamily and enhances insulin sensitivity. In an effort to develop a novel and effective thiazolidindione derivative, 5-{4-[2-(methyl-p-substituted phenylamino) ethoxy] benzyl} thiazolidine-2,4-diones 7 have been prepared by Mitsunobu reaction of the hydrophobic segment, methyl-p-substituted phenylaminoethanol 4 with hydroxybenzylthiazolidinedione 5 and their ability to activate PPARgamma and inhibit LPS-induced NO production were evaluated.