Influence of interleukin-1α on androgen receptor expression and cytokine secretion by cultured human dermal papilla cells

Injury-induced interleukin-1 alpha promotes Lgr5 hair follicle stem cells de novo regeneration and proliferation via regulating regenerative microenvironment in mice

BACKGROUND

The hair follicles (HFs) are barely regenerated after loss in injuries in mammals as well as in human beings. Recent studies have shown that the regenerative ability of HFs is age-related; however, the relationship between this phenomenon and the stem cell niche remains unclear. This study aimed to find a key secretory protein that promotes the HFs regeneration in the regenerative microenvironment.

METHODS

To explore why age affects HFs de novo regeneration, we established an age-dependent HFs regeneration model in leucine-rich repeat G protein-coupled receptor 5 (Lgr5) + /mTmG mice. Proteins in tissue fluids were analyzed by high-throughput sequencing. The role and mechanism of candidate proteins in HFs de novo regeneration and hair follicle stem cells (HFSCs) activation were investigated through in vivo experiments. The effects of candidate proteins on skin cell populations were investigated by cellular experiments.

RESULTS

Mice under 3-week-old (3W) could regenerate HFs and Lgr5 HFSCs, which were highly correlated with the immune cells, cytokines, IL-17 signaling pathway, and IL-1α level in the regeneration microenvironment. Additionally, IL-1α injection induced de novo regeneration of HFs and Lgr5 HFSCs in 3W mouse model with a 5 mm wound, as well as promoted activation and proliferation of Lgr5 HFSCs in 7-week-old (7W) mice without wound. Dexamethasone and TEMPOL inhibited the effects of IL-1α. Moreover, IL-1α increased skin thickness and promoted the proliferation of human epidermal keratinocyte line (HaCaT) and skin-derived precursors (SKPs) in vivo and in vitro, respectively.

CONCLUSIONS

In conclusion, injury-induced IL-1α promotes HFs regeneration by modulating inflammatory cells and oxidative stress-induced Lgr5 HFSCs regeneration as well as promoting skin cell populations proliferation. This study uncovers the underlying molecular mechanisms enabling HFs de novo regeneration in an age-dependent model.

Proprietary Herbal Extract Downregulates the Gene Expression of IL-1α in HaCaT Cells: Possible Implications Against Nonscarring Alopecia

Background

Currently while, topical minoxidil and oral finasteride are the only medications approved in androgenetic alopecia (AGA), the cause oriented treatment and immunsupressive treatment are being performed in telogen effluvium (TE) and alopecia areata (AA) respectively. Considering the inflammatory factors in the pathogenesis of these three nonscarring alopecia forms, we have formulated a mixture for topical usage composed of six different herbal extracts (HE) which have already known antiinflammatory and antioxidant features.

Materials and Methods

In addition to performing the phytochemical analysis of HE, we detected the gene expression level of IL-1α, the crucial hair loss mediator, for the putative efficacy in nonscarring alopecia. Cell proliferation assay was performed by XTT reagent. After determination of non-cytotoxic concentration, HaCaT cells were treated with HE. RNA isolations were carried out from both non-treated and treated cell groups by using TRI-reagent. Gene expressions of IL-1α and as control GAPDH were determined by RT-qPCR analysis.

Results

Results were represented as “IL-1α/GAPDH Fold Change”. HE solution caused statistically significant downregulation of IL-1α gene expressions (p<0.0001), compared to untreated control cells. HE treatment ended up with 0.1900 fold change for IL-1α.

Conclusion

IL-1α is a direct growth inhibitory agent in hair follicles and an important actor in the pathogenesis of AGA , TE, and AA. Considering together the vitamins, flavonoids, and trace elements identified in the phytochemical analyses and downregulation of IL-1α in HaCaT cells, our HE may be an auxiliary agent in the therapy of these three nonscarring alopecia forms.

Review of Hair Follicle Dermal Papilla cells as in vitro screening model for hair growth

Hair disorders such as hair loss (alopecia) and androgen dependent, excessive hair growth (hirsutism, hypertrichosis) may impact the social and psychological well-being of an individual. Recent advances in understanding the biology of hair have accelerated the research and development of novel therapeutic and cosmetic hair growth agents. Preclinical models aid in dermocosmetic efficacy testing and claim substantiation of hair growth modulators. The in vitro models to investigate hair growth utilize the hair follicle Dermal Papilla cells (DPCs), specialized mesenchymal cells located at the base of hair follicle that play essential roles in hair follicular morphogenesis and postnatal hair growth cycles. In this review, we have compiled and discussed the extensively reported literature citing DPCs as in vitro model to study hair growth promoting and inhibitory effects. A variety of agents such as herbal and natural extracts, growth factors and cytokines, platelet-rich plasma, placental extract, stem cells and conditioned medium, peptides, hormones, lipid-nanocarrier, light, electrical and electromagnetic field stimulation, androgens and their analogs, stress-serum and chemotherapeutic agents etc. have been examined for their hair growth modulating effects in DPCs. Effects on DPCs' activity were determined from untreated (basal) or stress induced levels. Cell proliferation, apoptosis and secretion of growth factors were included as primary end-point markers. Effects on a wide range of biomolecules and mechanistic pathways that play key role in the biology of hair growth were also investigated. This consolidated and comprehensive review summarizes the up-to-date information and understanding regarding DPCs based screening models for hair growth and may be helpful for researchers to select the appropriate assay system and biomarkers. This review highlights the pivotal role of DPCs in the forefront of hair research as screening platforms by providing insights into mechanistic action at cellular level, which may further direct the development of novel hair growth modulators.

Minoxidil Downregulates Interleukin-1 Alpha Gene Expression in HaCaT Cells

Introduction:

Minoxidil has been used topically to stimulate hair growth for male androgenetic alopecia (AGA) for more than 3 decades. It is currently being used for female AGA and alopecia areata (AA) as well. Although much time has passed since its first use, our understanding of its mechanism of action is highly limited. Therefore, we examined the inflammatory properties of AGA and AA, two entities in which minoxidil is being used as a therapeutic agent. We investigated the in vitro expression levels of cytokine interleukin-1 alpha (IL-1α), a potent inhibitor of hair growth, in minoxidil-treated human keratinocyte (HaCaT) cells to determine whether this molecule exerts anti-inflammatory effects.

Materials and Methods:

Cellular proliferation was examined using the Cell Proliferation Kit II (XTT) reagent. After determining a noncytotoxic concentration, HaCaT cells were treated with minoxidil. RNA was isolated from both untreated and treated cells with TRI Reagent^®. Expression of the IL-1α gene was determined by reverse transcription quantitative polymerase chain reaction analysis and is reported relative to glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which served as a control.

Results:

Results are presented as IL-1α/GAPDH fold change. Minoxidil treatment downregulated IL-1α expression by 0.3433-fold compared with untreated cells (P = 0.001).

Conclusion:

This anti-inflammatory effect of minoxidil, as evidenced by significant downregulation of IL-1α gene expression in HaCaT cells, may represent one of its mechanisms of action in alopecia.

Rice bran mineral extract increases the expression of anagen-related molecules in human dermal papilla through wnt/catenin pathway

The objective of this study is to evaluate of rice bran mineral extract (RBM) increases the expression of anagen-related molecules in human dermal papilla (DOCs). Four treatment groups were established to evaluate the efficacy of RBM, including a negative control, positive control (ascorbic acid), RBM and ortho-silicic acid (Si(OH)₄) (OSA) group. Three days after the DPCs were administered the various treatments, western blot analysis showed that type I collagen expression was increased 2.5-fold in the OSA group and 4-fold in the RBM group, and ALP expression was increased 1.5-fold in the OSA and RBM group while the expression of fibronectin was increased ~3-fold in the OSA group and 2.5-fold in the RBM group. Also, the expression of Wnt-3α and β-catenin protein was increased in OSA and RBM group compared to control group. Furthermore, the expression of IL-1a was decreased by more than 50% in the OSA and RBM groups compared to the negative control. Analysis of mRNA expression by RT-qPCR showed that type I collagen increased 1.2-fold in the OSA- and RBM-treated DPCs, whereas type IV collagen increased 2.7-fold in the OSA group and 3.5-fold in the RBM group. However, TGF-β2 mRNA decreased about 80% in the OSA and RBM groups, respectively. Immunohistochemical staining of the DPCs for versican protein showed a significant increase in the OSA- and RBM-treated groups compared to the negative control. Thus, RBM have a potential to recover of DPCs activity and decreased inflammatory-related markers. It can be expected that hair loss prevention and hair growth enhancement can be expected when RBM is applied as a cosmetic product.

Dermal-Epidermal Cross-Talk: Differential Interactions With Microvascular Endothelial Cells

The biological importance of circulatory blood supply and angiogenesis for hair growth is now well recognized, but the their regulatory mechanisms require more mechanistic investigation. In vitro cocultures and tricultures can be successfully employed to greatly improve our knowledge on paracrine crosstalk between cell types that populate the dermal-epidermal interface and cutaneous vasculature. Here we report that human dermal fibroblasts (NHDF) promote viability and proliferation of microvascular endothelial cells (HMVEC), while HMVEC are not mitogenic for NHDF. In triculture setup, conditioned media (CM) obtained by cocultures (HMVEC/NHDF or HMVEC/follicle fibroblasts) differently modulate growth and proliferation of keratinocytes and alter the expression of metabolic and pro-inflammatory markers. In conclusion, tricultures were successfully employed to characterize in vitro dermal-epithelial and endothelial interactions and could integrate ex vivo and in vivo approaches by the use of high-throughput and standardized protocols in controlled conditions. J. Cell. Physiol. 232: 897-903, 2017. © 2016 Wiley Periodicals, Inc.

Cystathionine metabolic enzymes play a role in the inflammation resolution of human keratinocytes in response to sub-cytotoxic formaldehyde exposure

Low-level formaldehyde exposure is inevitable in industrialized countries. Although daily-life formaldehyde exposure level is practically impossible to induce cell death, most of mechanistic studies related to formaldehyde toxicity have been performed in cytotoxic concentrations enough to trigger cell death mechanism. Currently, toxicological mechanisms underlying the sub-cytotoxic exposure to formaldehyde are not clearly elucidated in skin cells. In this study, the genome-scale transcriptional analysis in normal human keratinocytes (NHKs) was performed to investigate cutaneous biological pathways associated with daily life formaldehyde exposure. We selected the 175 upregulated differentially expressed genes (DEGs) and 116 downregulated DEGs in NHKs treated with 200μM formaldehyde. In the Gene Ontology (GO) enrichment analysis of the 175 upregulated DEGs, the endoplasmic reticulum (ER) unfolded protein response (UPR) was identified as the most significant GO biological process in the formaldeyde-treated NHKs. Interestingly, the sub-cytotoxic formaldehyde affected NHKs to upregulate two enzymes important in the cellular transsulfuration pathway, cystathionine γ-lyase (CTH) and cystathionine-β-synthase (CBS). In the temporal expression analysis, the upregulation of the pro-inflammatory DEGs such as MMP1 and PTGS2 was detected earlier than that of CTH, CBS and other ER UPR genes. The metabolites of CTH and CBS, l-cystathionine and l-cysteine, attenuated the formaldehyde-induced upregulation of pro-inflammatory DEGs, MMP1, PTGS2, and CXCL8, suggesting that CTH and CBS play a role in the negative feedback regulation of formaldehyde-induced pro-inflammatory responses in NHKs. In this regard, the sub-cytotoxic formaldehyde-induced CBS and CTH may regulate inflammation fate decision to resolution by suppressing the early pro-inflammatory response.

Topical application of Polygonum multiflorum extract induces hair growth of resting hair follicles through upregulating Shh and β-catenin expression in C57BL/6 mice

ETHNOPHARMACOLOGICAL RELEVANCE

Polygonum multiflorum has traditionally been used for treating patients suffering from baldness and hair loss in East Asia.

AIM OF THE STUDY

The present study sought to investigate the hair growth promoting activities of Polygonum multiflorum and its mechanism of action.

MATERIALS AND METHODS

The Polygonum multiflorum extract was topically applied to the shaved dorsal skin of telogenic C57BL6/N mice. To determine the effect of Polygonum multiflorum extract in telogen to anagen transition, the expression of β-catenin and Sonic hedgehog (Shh) was determined by immunohistochemistry analysis.

RESULTS

Polygonum multiflorum extract promoted hair growth by inducing anagen phase in telogenic C57BL6/N mice. In Polygonum multiflorum extract treated group, we observed increase in the number and the size of hair follicles that are considered as evidence for anagen phase induction. Immunohistochemical analysis revealed that earlier induction of β-catenin and Shh were observed in Polygonum multiflorum extract treated group compared to that in control group.

CONCLUSION

These results suggest that Polygonum multiflorum extract promotes hair growth by inducing anagen phase in resting hair follicles.

Alopecia universalis associated with impaired interleukin-4 production and low serum IgE level

A 17-year-old female presented with alopecia universalis, which appeared following widespread eczematous dermatitis. An immunohistochemical study demonstrated that CD8(+) T cells infiltrated into hair follicles with satellite cell necrosis of keratinocytes. The precedence of the autosensitization dermatitis suggested that T cells concerned with the eczematous reaction also attacked hair follicles, or alternatively, that those T cells sequentially activated another population of cytotoxic T cells. We found that she had a continuously low level of serum IgE (<1 units/ml), and this abnormality urged us to investigate interleukin (IL)-4 production of T cells. Although the patient had a normal number of CD4(+) T cells, the production of IL-4, but not IL-10, was profoundly impaired as assessed by a reverse transcriptase polymerase chain reaction analysis, suggesting the possible relationship between the baldness and IL-4 reduction. The autoimmune hair loss might occur via activation of cytotoxic T cells and Th(1) cells as a result of a relief from IL-4 control.