IGFBP-rP1 is a potential therapeutic target in androgenic alopecia.

The available interventions for androgenic alopecia (AGA), the most common type of hair loss worldwide, remain limited. The insulin growth factor (IGF) system may play an important role in the pathogenesis of AGA. However, the exact role of IGF binding protein-related protein 1 (IGFBP-rP1) in hair growth and AGA has not been reported. In this study, we first found periodic variation in IGFBP-rP1 during the hair cycle transition in murine hair follicles (HFs). We further demonstrated that IGFBP-rP1 levels were lower in the serum and scalp HFs of individuals with AGA than in those of healthy controls. Subsequently, we verified that IGFBP-rP1 had no cytotoxicity to human outer root sheath cells (HORSCs) and that IGFBP-rP1 reversed the inhibitory effects of DHT on the migration of HORSCs in vitro. Finally, a DHT-induced AGA mouse model was created. The results revealed that the expression of IGFBP-rP1 in murine HFs was downregulated after DHT treatment and that subcutaneous injection of IGFBP-rP1 delayed catagen occurrence and prolonged the anagen phase of HFs in mice with DHT-induced AGA. The present work shows that IGFBP-rP1 is involved in hair cycle transition and exhibits great therapeutic potential for AGA.

Kartogenin regulates hair growth and hair cycling transition.

Background: Kartogenin is a heterocyclic compound able to promote the proliferation, migration, and differentiation of various cell types and induce cartilage-like tissue regeneration. However, the role of kartogenin in hair follicles (HFs), remains unknown. We therefore investigated the effects of kartogenin on the regulation of hair growth and hair growth cycle transition. Methods: The effects of kartogenin on the proliferation, cell cycle status, and migration of primary human outer root sheath cells (ORSCs) were evaluated by MTS assay, flow cytometry, Transwell® and scratch assays, respectively. We exposed ORSCs to kartogenin (1 µM) and determined changes in mRNA and protein levels of transforming growth factor (TGF)-ß2/Smad signaling molecules by reverse transcription polymerase chain reaction, western blotting, and immunofluorescence. We also examined the effects of kartogenin (10 µM) on HFs in mice by histology following cutaneous injection. Results: Kartogenin enhanced ORSC proliferation and migration function in a dose-dependent manner, and downregulated the expression of TGF-ß2/Smad signaling molecules in vitro. Injection of kartogenin delayed catagen phase and increased regenerated hair length in mice in vivo. Conclusions: Kartogenin modulates HF growth and regulates the hair cycle and the TGF-ß2/Smad signaling pathway, providing a potential new approach for the treatment of hair loss.

Comparing the characteristics and predicting the survival of patients with head and neck melanoma versus body melanoma: a population-based study.

BACKGROUND: Previous studies reported cutaneous melanoma in head and neck (HNM) differed from those in other regions (body melanoma, BM). Individualized tools to predict the survival of patients with HNM or BM remain insufficient. We aimed at comparing the characteristics of HNM and BM, developing and validating nomograms for predicting the survival of patients with HNM or BM. METHODS: The information of patients with HNM or BM from 2004 to 2015 was obtained from the Surveillance, Epidemiology, and End Results (SEER) database. The HNM group and BM group were randomly divided into training and validation cohorts. We used the Kaplan-Meier method and multivariate Cox models to identify independent prognostic factors. Nomograms were developed via the rms and dynnom packages, and were measured by the concordance index (C-index), the area under the curve (AUC) of the receiver operating characteristic (ROC) curve and calibration plots. RESULTS: Of 70,605 patients acquired, 21% had HNM and 79% had BM. The HNM group contained more older patients, male sex and lentigo maligna melanoma, and more frequently had thicker tumors and metastases than the BM group. The 5-year cancer-specific survival (CSS) and overall survival (OS) rates were 88.1 ± 0.3% and 74.4 ± 0.4% in the HNM group and 92.5 ± 0.1% and 85.8 ± 0.2% in the BM group, respectively. Eight variables (age, sex, histology, thickness, ulceration, stage, metastases, and surgery) were identified to construct nomograms of CSS and OS for patients with HNM or BM. Additionally, four dynamic nomograms were available on web. The internal and external validation of each nomogram showed high C-index values (0.785-0.896) and AUC values (0.81-0.925), and the calibration plots showed great consistency. CONCLUSIONS: The characteristics of HNM and BM are heterogeneous. We constructed and validated four nomograms for predicting the 3-, 5- and 10-year CSS and OS probabilities of patients with HNM or BM. These nomograms can serve as practical clinical tools for survival prediction and individual health management.

Expression and localization of Sox10 during hair follicle morphogenesis and induced hair cycle.

Sox transcription factors play many diverse roles during development, including regulating stem cell states, directing differentiation, and influencing the local chromatin landscape. Sox10 has been implicated in the control of stem/progenitor activity and epithelial-mesenchymal transition, yet it has not been studied in relation to the hair follicle cycle or hair follicle stem cell (HFSC) control. To elucidate the role of Sox10 in hair follicle cycle control, we performed immunohistochemical and immunofluorescence analysis of its expression during hair morphogenesis, the postnatal hair cycle, and the depilation-induced murine hair follicle cycle. During hair follicle morphogenesis, Sox10 was expressed in the hair germ and peg. In telogen, we detected nuclear Sox10 in the hair bulge and germ cell cap, where HFSCs reside, while in anagen and catagen, Sox10 was detected in the epithelial portion, such as the strands of keratinocytes, the outer root sheath (ORS) in anagen, and the regressed epithelial strand of hair follicle in catagen. These results suggest that Sox10 may be involved in early hair follicle morphogenesis and postnatal follicular cycling.

Tranexamic Acid Inhibits Angiogenesis and Melanogenesis in Vitro by Targeting VEGF Receptors.

Melasma is a common but complex skin condition concerning cosmetic problems. Tranexamic acid (TA) has been proved to be effective in treatment of melasma with still unclear mechanisms. Here, we show that VEGF165 enhanced the expression of VEGF receptors (VEGFRs, including VEGFR-1, VEGFR-2 and NRP-1) in human umbilical vein endothelial cells (HUVECs), which was attenuated by TA. VEGF165 also promoted tyrosine phosphorylation of VEGFR-1 and VEGFR-2 in HUVECs, which was again abolished by TA. TA further showed similar effects to neutralization of VEGFR-1 and VEGFR-2 in inhibiting cell proliferation, migration, invasion and tube formation of HUVECs induced by VEGF165, suggesting that TA could inhibit angiogenesis by targeting VEGFRs in HUVECs. In addition, VEGF165 enhanced the expression of VEGFRs and promoted tyrosine phosphorylation of VEGFR-1 and VEGFR-2 in normal human melanocytes, which were also attenuated by TA. Furthermore, TA showed similar effects to neutralization of VEGFR-1 and VEGFR-2 in inhibiting tyrosinase activity, melanin production and even melanogenic proteins induced by VEGF165, suggesting that TA could reduce melanogenesis via inhibiting activation of VEGFRs and subsequent expression of melanogenic proteins in melanocytes. Taken together, we demonstrate that TA can inhibit angiogenesis and melanogenesis in vitro at least in part by targeting VEGFRs, which may offer a new understanding of the pathogenesis of melasma as well as the molecular mechanism for TA in treatment of the disease.

The renaissance of human skin organ culture: A critical reappraisal.

Human skin organ culture (hSOC) is a simple but highly instructive and clinically relevant skin research method. It has been used for decades to study the development, differentiation, and function as well as the response to wounding or test agents of intact human skin in the presence of its appendages and all resident cell populations. hSOC has also proven useful in toxicological and oncological studies and studies of skin aging (both chronological aging and photoaging), skin energy metabolism, skin immunology, pigmentation biology, and cutaneous (neuro-)endocrinology and neurobiology. The pathobiology and treatment of various dermatoses can also be assessed ex vivo by organ-culturing intact lesional human skin. In addition to morphological analyses by routine histochemistry, quantitative (immuno)histomorphometry has proven to be an excellent tool for quantitating and localizing protein expression patterns in defined skin compartments and distinct cell populations using a relatively small amount of precious human tissue. Finally, more recent technological advances, such as siRNA-mediated gene silencing and sensory reinnervation of hSOCs, have further extended the range of methodological applications for the ex vivo study of human skin; it has emerged as the ultimate preclinical assay system for investigative dermatology, including the testing of drugs, cosmeceuticals and nutraceuticals and more, and is just one step below human skin xenotransplant in vivo mouse models and clinical trials. Here, we critically review the renaissance and variety of hSOC assays, their applications and limitations, and we critically compare them with 3D skin "equivalent" assays. The review closes with perspectives on how this ancient but highly informative and physiologically relevant ex vivo skin research method may be further developed in the future.

Regulation of hair follicle development by exosomes derived from dermal papilla cells.

BACKGROUND: Dermal papilla cells (DPCs) play a critical role in the regulation of hair follicle (HF) growth, formation, and cycling. DPCs are thought to regulate HF growth through a paracrine mechanism, in which exosomes may play a critical role. METHODS: DPC-Exos were cutaneously injected into HFs at different HF cycle stages and the effects were evaluated by histological and immunohistochemical analyses. The effects of DPC-Exos on proliferation, migration, and cell cycle status of outer root sheath cells (ORSCs) were evaluated. After treatment of DPC-Exos, changes in mRNA and protein levels of ß-catenin and Sonic hedgehog (Shh) in ORSCs were detected. RESULTS: DPC-Exos were approximately 105 nm in diameter and expressed tumor susceptibility gene 101, cluster of differentiation (CD)9, and CD63. Injection of DPC-Exos accelerated the onset of HF anagen and delayed catagen in mice. Immunohistochemical analyses revealed that ß-catenin and Shh levels were upregulated in the skin. In vitro, DPC-Exo treatment enhanced ORSC proliferation and migration, and stimulated the expression of ß-catenin and Shh. CONCLUSION: DPC-Exos contribute to the regulation of HF growth and development, and provide a potential avenue for the treatment of hair loss.

Decorin promotes proliferation and migration of ORS keratinocytes and maintains hair anagen in mice.

DECORIN is a prototypical member of the small leucine-rich proteoglycan (SLRP) family that plays important roles in numerous biological processes and cellular biological pathways. We previously showed that Decorin expression was highly enhanced in mouse dorsal hair follicles (HFs) during the anagen phase and was reduced during the catagen and telogen phases, suggesting that Decorin might modulate follicular cycling and morphogenesis. In this study, to further clarify the effects of DECORIN on hair cells and the cycling transition, an in vitro overexpression strategy and Decorin-null (Dcn-/- ) mice were used to investigate the effects of DECORIN on outer root sheath (ORS) keratinocytes. DECORIN overexpression significantly enhanced proliferation and migration in ORS keratinocytes in vitro. Moreover, DECORIN overexpression upregulated the mRNA and protein expression levels of WNT10b, ß-CATENIN and LEF1. The DECORIN overexpression-induced increase in the proliferation and migration of ORS keratinocytes was partially inhibited by a Wnt/ß-catenin inhibitor. Furthermore, Dcn-/- mice had a shortened anagen phase and lower levels of ß-catenin expression than were observed in wild-type mice in imaging and histological analyses. Taken together, these findings suggest that DECORIN promotes the proliferation and migration of ORS keratinocytes in vitro and maintains hair anagen in mice.

Expression of decorin throughout the murine hair follicle cycle: hair cycle dependence and anagen phase prolongation.

Decorin is a prototypical member of the small leucine-rich proteoglycan (SLRP) family, which is involved in numerous biological processes. The role of decorin, as a representative SLRP, in hair follicle morphogenesis has not been elucidated. We present our initial findings on decorin expression patterns during induced murine hair follicle (HF) cycles. It was found that decorin expression is exclusively restricted to the epidermis, outer root sheath and sebaceous glands during the anagen phase, which correlates with the upregulation of decorin mRNA and protein expression in depilated murine dorsal skin. Furthermore, we used a functional approach to investigate the effects of recombinant human decorin (rhDecorin) via cutaneous injection into HFs at various murine hair cycle stages. The local injection of rhDecorin (100 µg/ml) into the hypodermis of depilated C57BL/6 mice at anagen delayed catagen progression. In contrast, rhDecorin injection during the telogen phase caused the premature onset of anagen, as demonstrated by the assessment of the following parameters: (i) hair shaft length, (ii) follicular bulbar diameter, (iii) hair follicle cycling score and (iv) follicular phase percentage. Taken together, our results suggest that decorin may modulate follicular cycling and morphogenesis. In addition, this study also provides insight into the molecular control mechanisms governing hair follicular epithelial-mesenchymal interactions.

Multiple tumors of the follicular infundibulum: a cutaneous reaction pattern?

The etiology of tumor of the follicular infundibulum (TFI) is unknown. Eruptive forms of TFI are rare. We present the case of a 49-year-old woman with multiple lesions on the arms, shoulders, trunk, buttocks, and legs of more than 3 years' duration. On clinical and histologic examination, a diagnosis of multiple TFI was made. Additionally, the patient presented with other rare remarkable features including severe pruritus, the Köbner phenomenon, and underlying inflammatory cell infiltration of the tumors. These findings strongly suggest that eruptive TFI may represent a kind of cutaneous reaction.

Unilateral generalized keratosis pilaris following pregnancy.

Keratosis pilaris (KP) is a common inherited disorder characterized by small folliculocentric keratotic papules that may have surrounding erythema, which gives the skin a stippled appearance resembling gooseflesh. The extensor surfaces of the upper arms, thighs, and buttocks commonly are affected, but a generalized presentation may occur. We report the case of a 29-year-old woman with unilateral generalized KP in the second month of her second pregnancy. Both a genetic mutation and pregnancy-induced hormonal changes played possible roles in the development and progress of unilateral generalized KP in this patient.

VEGF induces proliferation of human hair follicle dermal papilla cells through VEGFR-2-mediated activation of ERK.

Vascular endothelial growth factor (VEGF) is one of the strongest regulators of physiological and pathological angiogenesis. VEGF receptor 2 (VEGFR-2), the primary receptor for VEGF, is thought to mediate major functional effects of VEGF. Previously, we have localized both VEGF and VEGFR-2 in human hair follicles. In this study, we further defined the expression and roles of VEGFR-2 on human hair follicle dermal papilla (DP) cells. The expression of VEGFR-2 on DP cells was examined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis separately, and localization of VEGFR-2 was defined by immunofluorescence. The effect of VEGF on DP cells was analyzed by MTT assays and specific inhibitors. Finally, the role of VEGF involved in the signaling pathways was investigated by Western blot. RT-PCR and Western blot analysis demonstrated the expression of VEGFR-2 on DP cells. Immunostaining for VEGFR-2 showed strong signal on cultured human DP cells in vitro. Exogenous VEGF(165) stimulated proliferation of DP cells in a dose-dependent manner. Furthermore, this stimulation was blocked by a VEGFR-2 neutralizing antibody (MAB3571) and an ERK inhibitor (PD98059). VEGF(165)-induced phosphorylation of ERK1/2 was abolished by MAB3571 and PD98059, while the phosphorylation of p38, JNK and AKT were not changed by VEGF(165). Taken together, VEGFR-2 is expressed on primary human hair follicle DP cells and VEGF induces proliferation of DP cells through VEGFR-2/ERK pathway, but not p38, JNK or AKT signaling.

The evaluation of JAK inhibitors on effect and safety in alopecia areata: a systematic review and meta-analysis of 2018 patients.

Background: JAK inhibitors treat various autoimmune diseases, but an updated systematic review in treating alopecia areata is currently lacking. Objective: Evaluate the specific efficacy and safety of JAK inhibitors in alopecia areata by systematic review and meta-analysis. Methods: Eligible studies in PubMed, Embase, Web of Science, and Clinical Trials up to May 30, 2022, were searched. We enrolled in randomized controlled trials and observational studies of applying JAK inhibitors in alopecia areata. Results: 6 randomized controlled trials with 1455 patients exhibited SALT50 (odd ratio [OR], 5.08; 95% confidence interval [CI], 3.49-7.38), SALT90 (OR, 7.40; 95% CI, 4.34-12.67) and change in SALT score (weighted mean difference [WSD], 5.55; 95% CI, 2.60-8.50) compared to the placebo. The proportion of 26 observational studies with 563 patients of SALT5 was 0.71(95% CI, 0.65-0.78), SALT50 was 0.54(95% CI 0.46-0.63), SALT90 was 0.33(95% CI, 0.24-0.42), and SALT score (WSD, -2.18; 95% CI, -3.12 to -1.23) compared with baseline. Any adverse effects occurred in 921 of 1508 patients; a total of 30 patients discontinued the trial owing to adverse reactions. Limitations: Few randomized controlled trials met the inclusion criteria and insufficiency of eligible data. Conclusion: JAK inhibitors are effective in alopecia areata, although associated with an increased risk.

Expression and localization of Artemis serine 516 phosphorylation in human scalp skin.

Artemis phosphorylation at serine 516 (Ser516) has important regulatory functions in the repair of radiation-induced DNA damage, V(D)J recombination, p53-dependent apoptosis and cell cycle control. Accordingly, Artemis mutations can lead to Omenn syndrome, which is associated with human radiosensitive severe combined immunodeficiency syndrome and alopecia. In this study, we investigated the expression of Ser516 phosphorylation of Artemis in the epidermis and epidermal appendages in normal human scalp skin. Immunofluorescence analysis revealed Ser516 phosphorylation of Artemis in the upper and middle portion of anagen hair follicle [including outer root sheath (ORS), inner root sheath but not stratum basale], hair matrix, sebaceous glands (secretory and ductal portions), eccrine sweat glands (secretory and ductal portions) and epidermis (stratum basale and stratum granulosum), respectively. Artemis phosphorylation at Ser516 was most prominent in ORS keratinocytes. Therefore, we suggest that phosphorylation of Artemis at Ser516 could be involved in regulation of human epidermal appendages.

VEGF upregulates VEGF receptor-2 on human outer root sheath cells and stimulates proliferation through ERK pathway.

Vascular endothelial growth factor (VEGF) is a key regulator of physiological and pathological angiogenesis. The biological effects of VEGF are mediated by receptor tyrosine kinases. VEGF receptor-2, the primary receptor for VEGF, is thought to mediate most functional effects. In this study, we examined the expression and roles of VEGF receptor-2 on human outer root sheath cells (ORS). The expression of VEGFR-2 was determined at mRNA and protein levels by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Localization of VEGFR-2 in ORS cells was detected by immunofluorescence. The effect of VEGF on ORS cell proliferation was determined by MTT assays. Our data showed the expression of VEGFR-2 on ORS cells at both mRNA and protein levels. Immunostaining for VEGFR-2 demonstrated strong signal on cultured ORS cells. Exogenous VEGF(165) stimulated proliferation of ORS cells and upregulated expression of VEGFR-2 in a dose-dependent manner. Moreover, VEGF(165) induced phosphorylation of VEGFR-2, PLC-γ1, PKC-α, MEK, and p44/42 MAPK (ERK1/2) in a time-dependent manner. Taken together, human ORS cells express functional VEGF receptor-2 and exogenous VEGF(165) upregulates expression of VEGFR-2 and stimulates proliferation of ORS cells via VEGFR-2 mediated ERK signaling pathway.

A photo-triggering double cross-linked adhesive, antibacterial, and biocompatible hydrogel for wound healing.

Full-thickness wounds, lacking the epidermis and entire dermis and extending into subcutaneous fat, represent a common treatment challenge. Due to the loss of adnexal structures as a source of keratinocytes, full-thickness wounds healing can only be achieved by re-epithelialization from the wound edge and contraction. Here, we developed a hydrogel composed of chitosan methacrylate (CSMA) and o-nitrosobenzaldehyde-modified gelatin (GelNB) for promoting full-thickness wound healing. The CSMA/GelNB (CM/GN) hydrogels exhibited superior mechanical and adhesive properties than that of pure CSMA hydrogel. In vivo experiments confirmed that CM/GN could promote wound healing by generating more hair follicles and mutual blood vessels, high fibroblasts density, and thicker granulation tissue thickness. In addition, reduced secretions of tumor necrosis factor-α (TNF-α) and enhanced secretions of vascular endothelial growth factor (VEGF) could be observed in regenerated tissues after CM/GN treatment. These results suggested that CM/GN hydrogels could be promising candidates to promote wound healing.

An integrative analysis of the lncRNA-miRNA-mRNA competitive endogenous RNA network reveals potential mechanisms in the murine hair follicle cycle.

Alopecia is a common progressive disorder associated with abnormalities of the hair follicle cycle. Hair follicles undergo cyclic phases of hair growth (anagen), regression (catagen), and rest (telogen), which are precisely regulated by various mechanisms. However, the specific mechanism associated with hair follicle cycling, which includes noncoding RNAs and regulation of competitive endogenous RNA (ceRNA) network, is still unclear. We obtained data from publicly available databases and performed real-time quantitative polymerase chain reaction validations. These analyses revealed an increase in the expression of miRNAs and a decrease in the expression of target mRNAs and lncRNAs from the anagen to telogen phase of the murine hair follicle cycle. Subsequently, we constructed the ceRNA networks and investigated their functions using enrichment analysis. Furthermore, the androgenetic alopecia (AGA) microarray data analysis revealed that several novel alopecia-related genes were identified in the ceRNA networks. Lastly, GSPT1 expression was detected using immunohistochemistry. Our analysis revealed 11 miRNAs (miR-148a-3p, miR-146a-5p, miR-200a-3p, miR-30e-5p, miR-30a-5p, miR-27a-3p, miR-143-3p, miR-27b-3p, miR-126a-3p, miR-378a-3p, and miR-22-3p), 9 target mRNAs (Atp6v1a, Cdkn1a, Gadd45a, Gspt1, Mafb, Mitf, Notch1, Plk2, and Slc7a5), and 2 target lncRNAs (Neat1 and Tug1) were differentially expressed in hair follicle cycling. The ceRNA networks were made of 12 interactive miRNA-mRNA pairs and 13 miRNA-lncRNA pairs. The functional enrichment analysis revealed the enrichment of hair growth-related signaling pathways. Additionally, GSPT1 was downregulated in androgenetic alopecia patients, possibly associated with alopecia progression. The ceRNA network identified by our analysis could be involved in regulating the hair follicle cycle.

The PD-1/PD-L1 pathway in murine hair cycle transition: a potential anagen phase regulator.

Programmed cell death protein-1 (PD-1) is primarily recognized as an inhibitory receptor involved in the regulation of immunological tolerance. However, recent studies have indicated that PD-1/PD-L1 signaling could also regulate the functions of nonimmune cells and may be involved in regulating hair biology. In this study, we showed in a mouse model of depilation-induced hair cycling that PD-1/PD-L1 are expressed in the murine epidermis and hair follicle (HF) in a hair cycle-dependent manner. During HF morphogenesis, PD-1 expression was strongly decreased during the anagen phase compared with the catagen and telogen phases. PD-L1 expression was enhanced during the catagen phase compared with the anagen and telogen phases. Moreover, direct blockade of PD-L1 not only accelerated hair anagen phase onset but also delayed catagen progression. In conclusion, our findings indicated that PD-1/PD-L1 signaling may act as a negative regulator of hair cycle transition. Anti-PD-1/PD-L1 therapy may thus be a promising strategy for treating anagen-reduced hair loss.

Granulomatous rosacea-like skin rash: extranodal Rosai-Dorfman disease.

We report a 38-year-old man who presented with bilateral conjunctival congestion, hoarseness, and progressively growing pruritic, infiltrated skin lesions that had first begun over the face and neck, and later spread to the trunk and the limbs in 4 months. The clinical appearance of the lesions mimics granulomatous rosacea, acne vulgaris, or pityrosporum folliculitis. Histopathologic examination of the lesions from the face and chest both revealed dense dermal nodular lymphohistiocytic infiltrates which were positive for CD68 and S-100, but negative for CD1a. A systemic work-up for him detected no lymphadenopathy or other systemic involvement. A diagnosis of extranodal Rosai-Dorfman disease was made, and the patient received systemic glucocorticoids, with considerable improvement after 4 months of therapy.