Proliferation Of Hair Follicle Stem Cells Research Articles

Role of HFSCARC in hair follicle stem cell proliferation and differentiation in cashmere goat

AbstractAs a model of regenerative medicine, hair follicle stem cell (HFSC) plays a determining role in the hair cycle. Emerging evidences showed that long noncoding RNAs regulated the biological function of HFSC. In this current study, we found that lncRNA‐000552, standing for “goat secondary HFSC Associated SYNE3 Regulator of HF Cycle” (HFSCARC) expressed higher in anagen than that in telogen of cashmere goat. Through experiments involving nucleocytoplasmic separation and RNA‐FISH, we determined that HFSCARC was primarily located in the nucleus of HFSC. To understand the function of HFSCARC, the study performed various assays, including crystal violet staining, 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide, EdU, and flow cytometry analysis, which collectively revealed that HFSCARC inhibited HFSC proliferation. Additionally, HFSCARC promoted the differentiation of HFSC by investigating the expression of marker genes specific to stem cells and keratinocytes. RNA sequencing analysis was conducted to investigate the global gene expression changes associated with HFSCARC expression. The results showed that HFSCARC altered the expression of genes involved in cell proliferation, hair follicle development, and regulation of bone morphogenetic proteins (BMP) signaling. Furthermore, the study revealed that HFSCARC activated the BMP signaling pathway. Intriguingly, the study found a decreased expression of SYNE3, which was a neighboring gene of HFSCARC. The altered expression of genes associated with transmethylase and demethylase further suggested that HFSCARC might play an important role in regulating the SYNE3 expression. Overall, this study provides valuable insights into the regulatory role of HFSCARC in the biological function of HFSC. These findings contribute to a better understanding of the involvement of noncoding RNAs in the regulation of hair cycle.

Film-forming polymer solutions containing cholesterol myristate and berberine mediate pressure ulcer repair via the Wnt/β-catenin pathway.

Pressure ulcer (PU) is a worldwide problem that is difficult to address because of the related inflammatory response, local hypoxia, and repeated ischaemia/reperfusion, causing great suffering and financial burden to patients. Traditional Chinese medicine turtle plate powder can treat skin trauma, but its composition is complex and inconvenient to use. Here, we combined cholesterol myristate (S8) with berberine (BBR), with anti-inflammatory and antibacterial effects, as a drug and used hydroxypropyl methylcellulose and polyvinylpyrrolidone K30 as carriers to construct a novel film-forming polymeric solution (S8 + BBR FFPS), comprehensively study its reparative effect on PU and explore the potential mechanism in rat PU models. The results showed that S8 + BBR FFPS inhibits excessive inflammatory response, promotes re-epithelialization, and promotes hair follicle growth during the healing process of PU, which may be related to the activation of the Wnt/β-catenin signalling pathway by S8 + BBR FFPS to mediate hair follicle stem cell proliferation and maintain skin homeostasis. Therefore, S8 + BBR FFPS may be a potential candidate for the treatment of chronic skin injury, and its association with the Wnt/β-catenin signalling pathway may provide new ideas to guide the design of biomaterial-based wound dressings for chronic wound repair.

Photobiomodulation Facilitates Rat Cutaneous Wound Healing by Promoting Epidermal Stem Cells and Hair Follicle Stem Cells Proliferation.

Cutaneous wound healing represents a common fundamental phenomenon requiring the participation ofcells of distinct types and a major concern for the public. Evidence has confirmed that photobiomodulation (PBM) usingnear-infrared (NIR)can promote wound healing, but the cells involved and theprecise molecular mechanisms remain elusive. Full-thickness skin defects with a diameter of 1.0cm were made on the back of rats and randomly divided into the control group, 10J, 15J, and 30J groups. Thewound healing rate at days 4, 8, and 12 postoperativelywasmeasured.HE and Masson staining was conducted to revealthe histological characteristics. Immunofluorescence staining was performedto label the epidermal stem cells (ESCs) and hair follicle stem cells (HFSCs). Western blot was performed to detect the expressions ofproteins associated withESCs and HFSCs. Cutaneous wound tissues were collected for RNA sequencing. Gene ontology and the Kyoto Encyclopedia of Genes and Genomes analysis was performed, and the hub geneswereidentified usingCytoHubba and validated by qRT-PCR. PBM can promote reepithelialization, extracellular matrix deposition, and wound healing, increase the number of KRT14+/PCNA+ ESCs and KRT15+/PCNA+ HFSCs, and upregulate the protein expression of P63, Krt14, and PCNA. Three hundred and sixty-six differentially expressed genes (DEGs) and 7hubgenes includingSox9, Krt5, Epcam, Cdh1, Cdh3, Dsp, and Pkp3were identified. These DEGs are enriched in skin development, cell junction, and cadherin binding involved in cell-cell adhesion etc., while these hub genes are related toskin derived stem cells and cell adhesion. PBM accelerates wound healing by enhancing reepithelialization through promoting ESCs and HFSCs proliferation and elevating the expression of genes associated with stem cells and cell adhesion. This may provide a valuable alternative strategy to promote wound healing and reepithelialization by modulating the proliferation ofskin derived stem cells and regulating genes related to cell adhesion.

Effect study of Sonic hedgehog overexpressed hair follicle stem cells in hair follicle regeneration

To determine the expression level of Sonic hedgehog (Shh) in the passage of hair follicle stem cells (HFSCs), analyze the effect of Shh overexpression on the proliferation activity of HFSCs, and explore the survival of HFSCs after Shh overexpression and its effect on hair follicle regeneration. Hair follicles from the normal area (H1 group) and alopecia area (H2 group) of the scalp donated by 20 female alopecia patients aged 40-50 years old were taken, and the middle part of the hair follicle was cut under the microscope to culture, and the primary HFSCs were obtained and passaged; the positive markers (CD29, CD71) and negative marker (CD34) on the surface of the fourth generation HFSCs were identified by flow cytometry. The two groups of HFSCs were transfected with Shh-overexpressed lentivirus. Flow cytometry and cell counting kit 8 assay were used to detect the cell cycle changes and cell proliferation of HFSCs before and after transfection, respectively. Then the HFSCs transfected with Shh lentivirus were transplanted subcutaneously into the back of nude mice as the experimental group, and the same amount of saline was injected as the control group. At 5 weeks after cell transplantation, the expression of Shh protein in the back skin tissue of nude mice was detected by Western blot. HE staining and immunofluorescence staining were used to compare the number of hair follicles and the survival of HFSCs between groups. The isolated and cultured cells were fusiform and firmly attached to the wall; flow cytometry showed that CD29 and CD71 were highly expressed on the surface of the cells, while CD34 was lowly expressed, suggesting that the cultured cells were HFSCs. The results of real-time fluorescence quantitative PCR and Western blot showed that the expression levels of Shh protein and gene in the 4th, 7th, and 10th passages of cells in H1 and H2 groups decreased gradually with the prolongation of culture time in vitro. After overexpression of Shh, the proliferation activity of HFSCs in the two groups was significantly higher than that in the blank group (not transfected with lentivirus) and the negative control group (transfected with negative control lentivirus), and the proliferation activity of HFSCs in H1 group was significantly higher than that in H2 group before and after transfection, showing significant differences ( P<0.05). At 5 weeks after cell transplantation, Shh protein was stably expressed in the dorsal skin of each experimental group; the number of hair follicles and the expression levels of HFSCs markers (CD71, cytokeratin 15) in each experimental group were significantly higher than those in the control group, and the number of hair follicles and the expression levels of HFSCs markers in H1 group were significantly higher than those in H2 group, and the differences were significant ( P<0.05). Lentivirus-mediated Shh can be successfully transfected into HFSCs, the proliferation activity of HFSCs significantly increase after overexpression of Shh, which can secrete and express Shh continuously and stably, and promote hair follicle regeneration by combining the advantages of stem cells and Shh.

Hair follicle stem cell proliferation and differentiation are achieved by miR-1285-3P through targeted regulation of NOTCH pathway

The purpose of this experiment is to understand how miR-1285-3P regulates the NOTCH signaling pathway by targeting, thereby affecting the proliferation and differentiation of hair follicle stem cells. The cultured Inner Mongolia hair follicle stem cells were used in this experiment, and they were divided into control group, blank transfection group and miR-1285-3P transfection group. Among them, the control group was left untreated; the blank group was given miR-NC transfection; at the same time, the miR-1285-3P transfection group was given miR-1285-3P mimics for transfection. Compared with the control group (97.24 ± 6.81) and blank gro transfection up (97.32 ± 7.20), the cell proliferation ability of the miR-1285-3P transfection group (49.31 ± 3.39) was significantly lower. Compared with the other two groups, The proliferation ability of cells in the miR-1285-3P transfection group was decreased (P < 0.05); compared with the S-phase hair follicle stem cells in the control group (19.23 ± 1.29) and blank transfection group (19.38 ± 1.45), the miR-1285-3P transfection group (15.26 ± 1.26) decreased more significantly (P < 0.05). For hair follicle stem cells in each group, the proportion of cells in the G0-G1 phase was significantly different between the blank transfection group (63.18 ± 2.78) and the control group (64.29 ± 2.09), and the blank transfection group had a higher proportion (P < 0.05). In the process of miR-1285-3P targeting and regulating NOTCH signaling pathway, the proliferation and differentiation ability of hair follicle stem cells is affected. When NOTCH signaling pathway is activated, the differentiation of hair follicle stem cells is accelerated.

MiR-133a-3p regulates the growth of hair follicle stem cells in white goats from the Yangtze River Delta

The Yangtze River Delta white goats are the sole goat breed producing brush hair of high quality. Owing to the particularities of its wool production, a higher demand is placed on breeding efforts for this animal. Studies on the developmental mechanisms of the aligned hair follicle stem cells (HFSCs) provide a theoretical basis for molecular breeding. In the present study, HFSCs were isolated using the technique of immunohistochemistry from the cervical spinal skin tissue samples from the fetal sheep, and the miR-133a-3p expression was confirmed using quantitative reverse-transcription PCR (RT-qPCR) and western blotting experiments from the isolated HFSCs. Additionally, the effects on the proliferation and apoptosis of HFSCs were detected using flow cytometry and 5-ethynyl-2'-deoxyuridine assays, along with other methods, following the overexpression of miR-133a-3p or its inhibition. The experimental results revealed that miR-133a-3p overexpressed could inhibit the proliferation of HFSCs and promote apoptosis by specifically targeting DUSP6. While the miR-133a-3p knockdown could promote the proliferation but inhibit the apoptosis of the HFSCs. Meanwhile, the miR-133a-3p knockdown experiments showed opposite outcomes. These results illustrate the presence of a relevant network between DUSP6 and miR-133a-3p, which regulates the production of superior-quality brush hair.

Dermal PapillaCell-Derived Exosomes Regulate Hair Follicle Stem Cell Proliferation via LEF1.

Hair follicle (HF) growth and development are controlled by various cell types, including hair follicle stem cells (HFSCs) and dermal papilla cells (DPCs). Exosomes are nanostructures that participate in many biological processes. Accumulating evidence indicates that DPC-derived exosomes (DPC-Exos) mediate HFSC proliferation and differentiation during the cyclical growth of hair follicles. In this study, we found that DPC-Exos increase ki67 expression and CCK8 cell viability readouts in HFSCs but reduce annexin staining of apoptotic cells. RNA sequencing of DPC-Exos-treated HFSCs identified 3702 significantly differentially expressed genes (DEGs), including BMP4, LEF1, IGF1R, TGFβ3, TGFα, and KRT17. These DEGs were enriched in HF growth- and development-related pathways. We further verified the function of LEF1 and showed that overexpression of LEF1 increased the expression of HF development-related genes and proteins, enhanced HFSC proliferation, and reduced HFSC apoptosis, while knockdown of LEF1 reversed these effects. DPC-Exos could also rescue the siRNA-LEF1 effect in HFSCs. In conclusion, this study demonstrates that DPC-Exos mediated cell-to-cell communication can regulate HFSCs proliferation by stimulating LEF1 and provide novel insights into HF growth and development regulatory mechanisms.

Pyruvate Kinase M2 Promotes Hair Regeneration by Connecting Metabolic and Wnt/β-Catenin Signaling.

Hair follicle stem cells (HFSCs) utilize glycolytic metabolism during their activation and anagen induction. However, the role of pyruvate kinase M2 (PKM2), which catalyzes the final step of glycolysis, in hair regeneration has not been elucidated. In this study, we investigated the expression pattern and activity of PKM2 during the depilation-induced anagen progression in mice. We found that TEPP-46, a selective activator of PKM2, enhanced hair re-growth and proliferation of HFSCs. PKM2 expression was increased via up-regulation of Wnt/β-catenin signaling, which is involved in hair regeneration. Moreover, a combined treatment with KY19382, a small molecule that activates Wnt/β-catenin signaling, and TEPP-46 significantly enhanced hair re-growth and wound-induced hair follicle neogenesis (WIHN). These results indicate that simultaneous activation of the PKM2 and Wnt/β-catenin signaling could be a potential strategy for treating alopecia patients.

Insights into the regulation of MAP3K1 in hair follicle stem cells by transcriptome analysis

MAP3K1 is a significant member of the MAPK family, and its expressed MEKK1 protein has a wide range of biological activities and is an essential node in the MAPK signaling pathway. A significant number of studies have revealed that MAP3K1 plays a complicated function in the control of cell proliferation, apoptosis, invasion and movement, participates in the regulation of the immune system, and plays an important role in wound healing, tumorigenesis and other processes. In this study, we looked at the involvement of MAP3K1 in the control of hair follicle stem cells (HFSCs). Overexpression of MAP3K1 significantly promoted the proliferation of HFSCs by inhibiting apoptosis and promoting the transition from S phase to G2 phase. The transcriptome identified 189 (MAP3K1_OE) and 414 (MAP3K1_sh) differential genes. The two pathways with the most significant enrichment of differentially expressed genes were the IL-17 signaling pathway and TNF signaling pathway, and the significantly enriched terms in the GO enrichment analysis involved regulation of response of external stimulus, inflammatory and cytokine. Indicate that MAP3K1 can function as a promoting factor in HFSCs through the induction of cell cycle transition from S phase to G2 phase can inhibition apoptosis by mediating crosstalk among several pathways and cytokines. HIGHLIGHTS Abnormal MAP3K1 expression in hair follicle stem cells (HFSCs) can impair HFSC proliferation and apoptosis. MAP3K1 controls hair follicle stem cell proliferation via modulating cell apoptosis and the ratio of cells in S phase/G2 phase. The differential genes shared by MAP3K1_sh and MAP3K1_OE are enriched in GO terms such as inflammation, adipocyte differentiation, acute inflammation, and so on.

Exosomes Derived from Dermal Papilla Cells Mediate Hair Follicle Stem Cell Proliferation through the Wnt3a/β-Catenin Signaling Pathway.

Both hair follicle stem cells (HFSC) and dermal papilla cells (DPC) are essential for hair follicle growth and proliferation. In this study, HFSCs and DPCs that made signature proteins like KRT14, KRT15, KRT19, α-SMA, and Versican were obtained. Cell coculture systems between HFSCs and DPCs were used to measure the increased PCNA protein content in HFSCs. Additionally, exosomes from dermal papilla cells (DPC-Exos), the overexpression and silencing of Wnt3a, could regulate the Wnt/β-catenin signaling pathway downstream genes. After collecting DPC-ExosOE-Wnt3a, the treatment of HFSC with DPC-ExosOE-Wnt3a showed that DPC-ExosOE-Wnt3a could upregulate the mRNA expression of downstream genes in the Wnt/β-catenin signaling pathway and that DPC-ExosOE-Wnt3a enhanced the proliferation of HFSCs while inhibiting their apoptosis. These findings suggest that DPC-Exos could regulate HFSC cell proliferation via the Wnt3a/β-catenin signaling pathway. This research offers novel concepts for the molecular breeding and efficient production of Angora rabbits, as well as for the treatment of human hair problems.

Regulation of Proliferation and Apoptosis of Hair Follicle Stem Cells by miR-145-5p in Yangtze River Delta White Goats.

Yangtze River Delta white goats are the sole goat breed producing brush hair of high quality. The gene DUSP6 has been extensively studied in tumor cells but rarely in hair follicle stem cells (HFSCs). Per the previous sequencing data, it was determined that DUSP6 expression was up-regulated in superior-quality brush hair tissues, confirming it as a candidate gene associated with this trait. The targeting relationship of miR-145-5p with DUSP6 was determined based on online database prediction and was authenticated using a dual-luciferase gene reporter assay and quantitative reverse-transcription PCR (RT-qPCR). The regulatory effect of miR-145-5p on the growth of HFSCs was determined by targeting DUSP6 with RT-qPCR, 5-ethynyl-2'-deoxyuridine assays, Western blotting, and flow cytometry. The proliferation of HFSCs was inhibited and their apoptosis capacity was enhanced due to the presence of miR-145-5p. Therefore, it was proposed that this may have occurred through a repression effect of DUSP6 on the MAPK signaling pathway. The regulatory network of the HFSCs can be further understood using the theoretical basis established by the findings derived from this study.

601 Pharmacological inhibition of the chemokine receptor CX3CR1 promotes hair growth

Macrophages are located around hair follicles in normal skin and typically peak in density during the mid-telogen stage of the hair cycle. Hair follicles chemotactically attract macrophages and T cells and are in range to regulate hair follicle stem cells (HFSCs) quiescence, proliferation, and differentiation during physiologic and injured states. The expression of the fractalkine receptor CX3CR1 has been identified as a key regulator of macrophage and T cell migration and function at sites of inflammation.

BMP-AKT-GSK3β Signaling Restores Hair Follicle Stem Cells Decrease Associated with Loss of Sfrp1.

Wnt signaling plays a pivotal role in regulating activation, proliferation, stem cell renewal, and differentiation of hair follicle stem cells (HFSCs). Secreted frizzled-related protein 1 (Sfrp1), a Wnt antagonist is upregulated in the HFSCs; however, its role in the HFSCs regulation is still obscure. Here, we show that Sfrp1 loss showed a depletion of HFSCs, enhanced HFSC proliferation, and faster hair follicle cycle at PD21-PD28; HFSC markers, such as Lgr5 and Axin2, were decreased in both the Sfrp1+/- and Sfrp1-/- HFSCs. In addition, the second hair follicle cycle was also faster compared with WT. Importantly, Sfrp1-/- showed a restoration of HFSC by second telogen (PD49), whereas Sfrp1+/- did not show restoration with still having a decreased HFSC. In fact, restoration of HFSCs was due to a pronounced downregulation of β-catenin activity mediated through a cross-talk of BMP-AKT-GSK3β signaling in Sfrp1-/- compared with Sfrp1+/-, where downregulation was less pronounced. In cultured keratinocytes, Sfrp1 loss resulted in enhanced proliferation and clonogenicity, which were reversed by treating with either BMPR1A or GSK3β inhibitor thereby confirming BMP-AKT-GSK3β signaling involved in β-catenin regulation in both the Sfrp1+/- and Sfrp1-/- mice. Our study reveals a novel function of Sfrp1 by unraveling an in vivo molecular mechanism that regulates the HFSCs pool mediated through a hitherto unknown cross-talk of BMP-AKT-GSK3β signaling that maintains stem cell pool balance, which in turn maintains skin tissue homeostasis.

MicroRNA-149-Mediated MAPK1/ERK2 Suppression Attenuates Hair Follicle Stem Cell Differentiation.

Hair follicle stem cells (HFSCs) are responsible for hair growth and hair follicle regeneration. MicroRNAs have been demonstrated to be involved in the differentiation of HFSCs. Thus, this study aimed to explore the potential role of miR-149 in the differentiation of HFSCs. The isolated HFSCs were identified by flow cytometric sorting. miR-149 expression was determined during differentiation of HFSCs. Gain- and loss-of-function approaches were conducted to explore the roles of miR-149, MAPK1/ERK2, and FGF2/c-MYC in colony formation and proliferation of HFSCs. Furthermore, in vivo assays were undertaken in miR-149 knockout mice to confirm their roles in HFSC differentiation. miR-149 was found to be downregulated during HFSC differentiation, and overexpressed miR-149 restricted the proliferation and differentiation of HFSCs. miR-149 was confirmed to target and inhibit MAPK1/ERK2, which was highly expressed in and positively associated with HFSC differentiation. The MAPK1/ERK2 promotion in HFSC differentiation was achieved by augmenting expression of FGF2 and c-MYC. The in vitro effects of miR-149 were validated in in vivo experiments. Taken together, upregulated miR-149 restricted HFSC differentiation and hair growth by targeting MAPK1/ERK2 to reduce expression of FGF2 and c-MYC, which sheds light on the underlying molecular mechanism of hair growth.

Exosomal miRNA-181a-5p from the cells of the hair follicle dermal papilla promotes the hair follicle growth and development via the Wnt/β-catenin signaling pathway

Exosomal miRNAs are verified critical biomarkers, which participate in several biological processes. The growth and development of the hair follicle (HF) are typically controlled by the exosomal miRNAs via cell-to-cell communication. This study identified a high expression of miR-181a-5p in the low-passage DPC-Exos (exosomes derived from dermal papilla cell), revealing the transportation patterns of the DPC-Exos-derived miR-181a-5p entering the HFSC (hair follicle stem cell). The exosomal miR-181a-5p activates the Wnt/β-catenin signaling pathway by targeting the Wnt inhibitor WIF1 and thereby regulates the proteins and genes related to HF growth and development. Moreover, the exosomal miR-181a-5p was found to suppress the HFSC apoptosis but promoted the HFSC proliferation. The in vitro culture of the HF organ revealed that the exosomal miR-181a-5p possesses a positive role in hair growth. Collectively, the exosomal miR-181a-5p affects the HF growth and development through the Wnt/β-catenin signaling pathway. The exosomal miR-181a-5p might, therefore, act as the novel biomarker and therapeutic target for treating hair-related diseases and wool production in mammals.

Micro-Injury Induces Hair Regeneration and Vitiligo Repigmentation Through Wnt/β-Catenin Pathway.

Extrinsic injury can evoke intrinsic stimulation and subsequently initiate the physiological repair process. This study aims to investigate whether clinically acceptable micro-injury could be used to create local stimuli to induce hair regeneration and vitiligo repigmentation. A novel device was designed and manufactured to precisely control the micro-injury parameters. Then the most appropriate extent of micro-injury without over-damaging the skin was evaluated. Finally, the effects of micro-injury on hair regeneration and vitiligo repigmentation were examined by macroscopic observation, histological staining, gene and protein expression analysis. We discover that proper micro-injury effectively induces hair regeneration by activating the hair follicle stem cell proliferation and migration downwards to the hair matrix, finally shifting the hair follicle stage from telogen into anagen. On vitiligo model mice, micro-injury also induces the hair follicle melanocyte stem cells to migrate upwards to the interfollicular epidermis, activating and giving rise to melanocytes to repopulate the vitiligo lesion. Mechanistic analysis indicates that the canonical Wnt/β-catenin pathway plays a key role in the micro-injury-induced repair process. This study demonstrates that micro-injury has great potential in inducing hair regeneration and vitiligo repigmentation, laid a foundation to develop a micro-injury-based treatment method in alopecia and vitiligo.

MiR-1 Regulates Differentiation and Proliferation of Goat Hair Follicle Stem Cells by Targeting IGF1R and LEF1 Genes

Hair follicle stem cells (HFSCs) play a significant role in hair development. miR-1 has been reported as an important regulatory factor that affects hair follicle growth and development, but its regulatory mechanism on HFSC development remains unknown. In this study, the molecular mechanism of miR-1 in regulating HFSC proliferation and differentiation was investigated. High-throughput RNA-seq and integrated analysis were performed to identify differentially transcribed mRNAs and microRNAs (miRNAs) in HFSCs co-cultured with dermal papilla cells (named dHFSCs) and control HFSCs. We then determined the molecular function of miR-1 in HFSCs. Compared with HFSCs, 13 differentially transcribed miRNAs were identified in dHFSCs. The in vitro results indicated that the overtranscription of miR-1 inhibited HFSC proliferation, but enhanced HFSC differentiation by targeting IGF1R and LEF1 genes. This study provides new insights into the molecular mechanisms of HFSC development. Approval ID (2014ZX08008-002).

DUSP6 inhibits the proliferation of hair follicle stem cells (HFSCs) in vitro

RNA-seq has shown that the DUSP6 and MAPK signaling pathways are associated with the production of high-quality brush hair (type III hair) in Yangtze River Delta white goats. However, there are few reports on the regulatory effects of DUSP6 expression on hair follicle stem cells (HFSCs) and cellular processes, as well as the underlying mechanism. Here, we investigated the effect of DUSP6 level in HFSCs and the molecular mechanism underlying the functional regulation of HFSCs by DUSP6. Overexpression of DUSP6 significantly suppressed the proliferation of HFSCs by inducing cell cycle arrest in the G1 phase and by promoting apoptosis. Transcriptome analysis revealed a total of 217 differentially expressed genes between DUSP6-overexpressing and control HFSCs, of which 33 (15.2%) were upregulated in DUSP6-overexpressing cells. The two pathways with the most significant enrichment of differentially expressed genes were the TNF signaling pathway and cytokine-cytokine receptor interaction pathway, and the significantly enriched terms in the GO enrichment analysis involved cell attachment and cytokines. These results indicate that DUSP6 can function as an inhibitory factor in HFSCs through the induction of cell cycle arrest in the G1 phase and can promote apoptosis by mediating crosstalk among several pathways and cytokines. Highlights We constructed DUSP6 overexpression vectors to detect mRNA and protein expression levels related to high-quality brush hair in MAPK signaling pathway. We found that high expression level of DUSP6 can inhibit the proliferation of hair follicle stem cells (HFSCs) and promote cell apoptosis of HFSCs. DUSP6 may be involved in the growth regulation of HFSCs like Other studies in cancer, tumors by regulating the expression of cytokines, changing the transmission of signals between cells, activating or suppressing immune-related pathways.

Deficiency of Formyl Peptide Receptor 2 Retards Hair Regeneration by Modulating the Activation of Hair Follicle Stem Cells and Dermal Papilla Cells in Mice.

Hair loss is one of the most common chronic diseases, with a detrimental effect on a patient's psychosocial life. Hair loss results from damage to the hair follicle (HF) and/or hair regeneration cycle. Various damaging factors, such as hereditary, inflammation, and aging, impair hair regeneration by inhibiting the activation of hair follicle stem cells (HFSCs) and dermal papilla cells (DPCs). Formyl peptide receptor 2 (FPR2) regulates the inflammatory response and the activity of various types of stem cells, and has recently been reported to have a protective effect on hair loss. Given that stem cell activity is the driving force for hair regeneration, we hypothesized that FPR2 influences hair regeneration by mediating HFSC activity. To prove this hypothesis, we investigated the role of FPR2 in hair regeneration using Fpr2 knockout (KO) mice. Fpr2 KO mice were found to have excessive hair loss and abnormal HF structures and skin layer construction compared to wild-type (WT) mice. The levels of Sonic hedgehog (Shh) and β-catenin, which promote HF regeneration, were significantly decreased, and the expression of bone morphogenetic protein (Bmp)2/4, an inhibitor of the anagen phase, was significantly increased in Fpr2 KO mice compared to WT mice. The proliferation of HFSCs and DPCs was significantly lower in Fpr2 KO mice than in WT mice. These findings demonstrate that FPR2 impacts signaling molecules that regulate HF regeneration, and is involved in the proliferation of HFSCs and DPCs, exerting a protective effect on hair loss.

TMT-Based Quantitative Proteomic Analysis Reveals the Effect of Bone Marrow Derived Mesenchymal Stem Cell on Hair Follicle Regeneration.

Hair loss (HL) is a common chronic problem of poorly defined etiology. Herein, we explored the functionality of bone marrow-derived mesenchymal stem cell (BMSC) and conditioned medium (MSC-CM) as regulators of hair follicle proliferation and regeneration, and the mechanistic basis for such activity. BMSC were cultured and identified in vitro through the induction of multilineage differentiation and the use of a CCK-8 kit. The dorsal skin of mice was then injected with BMSC and MSC-CM, and the impact of these injections on hair cycle transition and hair follicle stem cell (HFSC) proliferation was then evaluated via hematoxylin and eosin (H&E) staining and immunofluorescent (IF) staining. We then conducted a tandem mass tags (TMT)-based quantitative proteomic analysis of control mice and mice treated with BMSC or MSC-CM to identify differentially expressed proteins (DEPs) associated with these treatments. Parallel reaction monitoring (PRM) was utilized as a means of verifying our proteomic analysis results. Herein, we found that BMSC and MSC-CM injection resulted in the transition of telogen hair follicles to anagen hair follicles, and we observed the enhanced proliferation of HFSCs positive for Krt15 and Sox9. Our TMT analyses identified 1,060 and 770 DEPs (fold change＞1.2 or＜0.83 and p ＜ 0.05) when comparing the BMSC vs. control and MSC-CM vs. control groups, respectively. Subsequent PRM validation of 14 selected DEPs confirmed these findings, and led to the identification of Stmn1, Ncapd2, Krt25, and Ctps1 as hub DEPs in a protein-protein interaction network. Together, these data suggest that BMSC and MSC-CM treatment can promote the proliferation of HFSCs, thereby facilitating hair follicle regeneration. Our proteomics analyses further indicate that Krt25, Cpm, Stmn1, and Mb may play central roles in hair follicle transition in this context and may represent viable clinical targets for the treatment of HL.