Induce Hair Follicle Regeneration Research Articles

Triethylene Glycol Squalene Improves Hair Regeneration by Maintaining the Inductive Capacity of Human Dermal Papilla Cells and Preventing Premature Aging.

De novo hair follicle (HF) regeneration, achieved through the replenishment of the dermal papilla (DP), acknowledged as the principal orchestrator of the hair growth cycle, is emerging as a prospective therapeutic intervention for alopecia. Nonetheless, multiple attempts have shown that these cells lose key inductive properties when cultured in a two-dimensional (2D) monolayer, leading to precocious senescence engendered by oxidative stress and inflammatory processes. Consequently, the three-dimensional (3D) spheroid technique is presently widely employed for DP cell culture. Nevertheless, substantiating the regenerative potential of these cells within the hair follicle (HF) milieu remains a challenge. In this current study, we aim to find a new approach to activate the inductive properties of DP cells. This involves the application of hair-growth-stimulating agents that not only exhibit concurrent protective efficacy against the aging process but also induce HF regeneration. To achieve this objective, we initially synthesized a novel highly amphiphilic derivative derived from squalene (SQ), named triethylene glycol squalene (Tri-SQ). Squalene itself is a potent antioxidant and anti-inflammatory compound traditionally employed as a drug carrier for alopecia treatment. However, its application is limited due to its low solubility. Subsequently, we applied this newly synthesized derivative to DP cells. The data obtained demonstrated that the derivative exhibits robust antioxidant and anti-inflammatory activities while concurrently promoting the expression of genes associated with hair growth. Moreover, to further assess the hair regrowth inductive properties of DP cells, we cultured the cells and treated them with Tri-SQ within a 3D spheroid system. Subsequently, these treated cells were injected into the previously depilated dorsal area of six-week-old male C57BL/6 mice. Results revealed that 20 days postinjection, a complete regrowth of hair in the previously hairless area, particularly evident in the case of 3D spheroids treated with the derivative, was observed. Additionally, histological and molecular analyses demonstrated an upregulation of markers associated with hair growth and a concurrent decrease in aging hallmarks, specifically in the 3D spheroids treated with the compound. In summary, our approach, which involves the treatment of Tri-SQ combined with a 3D spheroid system, exhibited a notably robust stimulating effect. This effect was observed in the induction of inductive properties in DP cells, leading to HF regeneration, and concurrently, it demonstrated an inhibitory effect on cellular and follicular aging.

Green fabrication of seedbed-like Flammulina velutipes polysaccharides–derived scaffolds accelerating full-thickness skin wound healing accompanied by hair follicle regeneration

A novel seedbed-like scaffold was firstly fabricated by the “frozen sectioning” processing method using Flammulina velutipes as a raw material. The Flammulina velutipes polysaccharides scaffold is composed of a natural structure imitating the “ground” (connected and aligned hollow tubes with porous walls). Meanwhile, its biologically active components include polysaccharides and proteins, mimicking the “plant nutrition” in the seedbed. To further optimize the ground and nutrition components, Flammulina velutipes polysaccharides–derived scaffolds (FPDSs) were fabricated via the treatment of original Flammulina velutipes polysaccharides scaffold (labeled FPS) by NaOH, cysteine (labeled as FPS/NaOH, FPS/Cys, respectively). FPDSs were characterized by SEM, FTIR, XRD, water absorption and retention, and mechanical evaluations. From the results, FPS/NaOH and FPS/Cys lost the characteristic big tubes of original strips and had higher water absorption capacities comparing to FPS. Simultaneously, FPS/NaOH had better ductility, FPS/Cys had showed increased stiffness. Biological activities of FPDSs were tested against different types of bacteria exhibiting excellent anti-bacterial activity, and FPS/NaOH and FPS/Cys had dramatically higher anti-bacterial activity than FPS. The cytocompatibility of FPDSs was evaluated utilizing mouse fibroblast cell line (L929), and all FPDSs showed good cytocompatibility. The FPDSs were further applied to a rat full-thickness skin wound model, and they all exhibited obviously accelerated re-epithelialization, among which FPS/NaOH showed the greatest efficiency. FPS/NaOH could shorten the wound-healing process as evidenced by dynamic alterations of the expression levels of specific stagewise markers in the healing areas. Similarly, FPS/NaOH can efficiently induce hair follicle regeneration in the healing skin tissues. In summary, FPDSs exhibit potential functions as seedbeds to promote the regeneration of the “seed” including hair follicles and injured skin, opening a new avenue for wound healing.

LncRNA-XIST promotes dermal papilla induced hair follicle regeneration by targeting miR-424 to activate hedgehog signaling

BackgroundAlopecia is a highly prevalent disease characterizing by the loss of hair. Dermal papilla (DP) cells are the inducer of hair follicle regeneration, and in vitro three-dimensional (3D) culturing DP cells have been proven to induce hair follicle regeneration. However, the molecular mechanisms behind the regulation of 3D culturing DP cells remain unclear. Methods3D-cultivated DP cells were used as in vitro cell model. DP sphere xenograft to nude mice was performed for in vivo study of hair follicle regeneration. qRT-PCR, Western blotting, and immunofluorescence were used for detecting the level of XIST, miR-424 and Hedgehog pathway-related proteins, respectively. H&E staining was used to examine hair neogenesis. Cell viability, proliferation and ALP activity were measured by MTT, CCK-8 and ELISA assays, respectively. Luciferase assays were used for studying molecular regulation between XIST, miR-424 and Shh 3′UTR. ResultsXIST and Shh were up-regulated, and miR-424 was down-regulated in 3D DP cells. Molecular regulation studies suggested that XIST sponged miR-424 to promote Shh expression. Knockdown of XIST suppressed DP cell activity, cell proliferation, ALP activity and the expression of other DP markers by sponging miR-424. Knockdown of XIST suppressed Shh mediated hedgehog signaling by targeting miR-424. Moreover, the knockdown of XIST inhibited DP sphere induced in vivo hair follicle regeneration and hair development. ConclusionXIST sponges miR-424 to promote Shh expression, thereby activating hedgehog signaling and facilitating DP mediated hair follicle regeneration.

Identification of key genes induced by platelet-rich plasma in human dermal papilla cells using bioinformatics methods.

Dermal papilla cells (DPCs) are located at the base of hair follicles, and are known to induce hair follicle regeneration. Platelet-rich plasma (PRP) functions in hair follicle regeneration. To investigate the influence of PRP on DPCs, the present study analyzed RNA-seq data of human hair dermal papilla cells (HHDPCs) that were treated or untreated by PRP. The data included in the RNA-seq were from two normal and two treated HHDPC samples. Following identification by Cuffdiff software, differentially expressed genes (DEGs) underwent enrichment analyses, and protein-protein interaction networks were constructed using Cytoscape software. Additionally, transcription factor (TF)-DEG and TF-long non-coding RNA (lncRNA) regulatory networks were constructed. A total of 178 differentially expressed lncRNA were screened, 365 were upregulated and 142 were downregulated. Notably, upregulated cyclin dependent kinase 1 (CDK1) (degree=76), polo-like kinase 1 (PLK1) (degree=65), cell division cycle 20 (degree=50), cyclin B1 (degree=49), aurora kinase B (degree=47), cyclin dependent kinase 2 (degree=46) and downregulated v-myc avian myelocytomatosis viral oncogene homolog (MYC) (degree=12) had higher degrees in networks. In addition, CCAAT/enhancer binding protein β, E2F transcription factor 1 (E2F1), early growth response 1 and MYC may be key TFs for their target genes, and were enriched in pathways associated with the cell cycle. They may also be involved in cell proliferation via various interactions with other genes, for example CDK1-PLK1 and E2F1→CDK1. These dysregulated genes induced by PRP may affect proliferation of HHDPCs.

Immunohistochemical study of hair follicle stem cells in regenerated hair follicles induced by Wnt10b.

The regulation of the periodic regeneration of hair follicles is complicated. Although Wnt10b has been reported to induce hair follicle regeneration, the characteristics of induced hair follicles, especially the target cells of Wnt10b, have not yet been clearly elucidated. Thus, we systematically evaluated the expression and proliferation patterns of Wnt10b-induced hair follicles. We found that Wnt10b promoted the proliferation of hair follicle stem cells from 24 hours after AdWnt10b injection. Seventy-two hours after AdWnt10b injection, cells outside of bulge area began to proliferate. When the induced hair follicle entered full anagen, although the hair follicle stem cells were normal, canonical Wnt signaling was maintained in the hair precortex cells. Our results reveal that the target cells that overexpressed Wnt10b included hair follicle stem cells, hair precortex cells, and matrix cells.

Adenovirus-Mediated Wnt10b Overexpression Induces Hair Follicle Regeneration

Hair follicles periodically undergo regeneration. The balance between activators and inhibitors may determine the time required for telogen hair follicles to reenter anagen. We previously reported that Wnt10b (wingless-type mouse mammary tumor virus integration site family member 10b) could promote the growth of hair follicles in vitro. To unveil the roles of Wnt10b in hair follicle regeneration, we established an in vivo mouse model using intradermal injection. On the basis of this model, we found that Wnt10b could induce the biological switch of hair follicles from telogen to anagen when overexpressed in the skin. The induced hair follicles expressed structure markers and could cycle normally into catagen. Conversely, anagen onset was abrogated by the knockdown of Wnt10b with small interfering RNA (siRNA). The Wnt10b aberrant expression data suggest that it is one of the activators of hair follicle regeneration. The β-catenin protein is translocated to the nucleus in Wnt10b-induced hair follicles. The biological effects of Wnt10b were abrogated when β-catenin expression was downregulated with siRNA. These data revealed that Wnt10b might induce hair follicle regeneration in vivo via the enhanced activation of the canonical Wnt signaling pathway. To our knowledge, our data provide previously unreported insights into the regulation of hair follicle cycling and provide potential therapeutic targets for hair follicle-related diseases.

Relation between dermal papilla cells and androgenetic alopecia

Androgenetie alopecia(AGA),the most common baldness,is a polygenic hereditary disease of unknown origin.It has been revealed that the pathogenesis of AGA is associated with androgen (especially dihydrotestosterone) and with mental factors.Dermal papilla cells (DPC),which originate from fibroblasts,are mesenehyme cells of hair papilla.DPC express androgen receptors,secrete a variety of cell factors,induce hair follicle regeneration and play an important role in hair follicle cycle.In addition,DPC are concerned with the metabolism of androgen that can stimulate DPC from sensitive hair follicles to secrete soluble cell factors and result in baldness.Therofore,DPC have a close relationship with AGA. Key words: Dermal papilla cells; Alopecia; Androgens

Biological characteristics and functions of dermal papilla cells

Dermal papilla cells (DPC) play an essential role in embryonic formation of hair follicles, regulation of hair growth cycle and maintenance of hair growth. It has been proved that cultured DPC have the ability to induce hair follicle regeneration in vivo and in vitro. At the same time, DPC have obvious properties of adult stem cells. Biological characteristics and functions of DPC are a focus in hair follicle cell biology research, and to study into them will provide theoretical basis for the diagnosis and treatment of hair loss, construction of tissue engineering skin with hair follicles and stem cell-based tissue engineering research. Key words: Hair follicle; Dermal papilla cells; Stem cells; Biology

Induction of hair follicle regeneration in rat ear by microencapsulated human hair dermal papilla cells

To induce hair follicle regeneration in rat ear by microencapsulated dermal papillae (DP) cells. Intact dermal papillae were obtained from human scalp follicles which were digested with collagenase I. The human hair DP cells were encapsulated with alginate-polylysine-alginate (APA) by a high-voltage electric field droplet generator. The diameters of the DP cell microcapsules were optimized by regulating the voltage, the distance between the needle head and the solution surface and the injection speed. Then DP cell microencapsulations were xenotransplanted into ears of 20 SD rats with a novel method. One rat was killed every week at the postoperative 2-12 weeks and the implantation sites were biopsied for histological observation. The DP cell microencapsulations were found in a group of round, smooth and transparent microcapsules under a phase-contrast microscope. The optimal combination of parameters to obtain 0.4 mm DP cell microcapsules was voltage 7.0 kV, injection speed 55 mm/h, and distance 10 mm. After 4-12 weeks, 18 of 20 DP cell microcapsule implantations had produced high-density hair. Histological observation indicated that both large follicles and sebaceous gland structures were formed in the rat ear within 3-12 weeks. These findings show that the DP cell microencapsulation maintain the capacity for initiating the follicle regeneration and can be considered as a substitute for fresh isolated dermal papillae.

Biological characterization of cultured dermal papilla cells and hair follicle regeneration in vitro and in vivo

Dermal papilla cells (DPC) are a group of mesenchyme-derived cells at the base of the hair follicle, where they regulate and control hair follicle growth through the expression and secretion of cytokines. Nevertheless, the role of DPC derived chemokines and other cytokines in the hair follicle biology remain speculative. In this study, we investigated the expression of basic fibroblast growth factor (bFGF), endothelin-1 (ET-1) and stem cell factor (SCF) in different passages of cultured DPC and their effects on the biological behaviour of DPC. The expression of bFGF, ET-1 and SCF in different passages of cultured DPC and their possible effects on the biological behavior of DPC are investigated using in situ hybridization and immunochemistry. In addition, we performed transplantation of hair follicle cells into nude mice. The cultured DPC, dermal sheath cells and fibroblast of human scalp, respectively, were mixed with cells of the hair follicle epithelium in different ratios, and then were cultured in hair follicle organotypic cultures or implanted into the subcutis of nude mice. The expression of ET-1 and SCF in early passages of cultured DPC became stronger, but turned weaker and even negative in late passages (> 6 passages). Hair follicle-like structures were formed after DPC combined with the cells of hair follicle epithelium cells in hair follicle organotypic cultures. When hair follicle organotypic cultures were implanted into the subcutis of nude mice, the relative intact hair follicles were formed. After the transplantation of hair follicle cells into the nude mice, the hair follicle-like structure was formed in the group that contained DPC mixed with hair follicle epithelium cells. However, no hair follicles were formed in the other two groups. It was found that the higher the expression of ET-1 and SCF in DPC, the stronger the ability of DPC to induce hair follicle regeneration. The cultured DPC can induce hair follicle regeneration and sustain hair growth in vivo and in vitro. Moreover, the expression of ET-1 and SCF is correlated with the ability of DPC inducing hair follicle regeneration.

Cultured human and rat tooth papilla cells induce hair follicle regeneration and fiber growth

The mesenchymal–epithelial interactions that characterize the early stages of tooth and hair follicle morphogenesis share certain similarities, and there is increasing evidence that mesenchymal cells derived from both mature structures retain interactive and stem cell-like properties. This study aimed to gauge the cross-appendage inductive capabilities of cultured tooth dental papilla (or pulp) cells from different species and ages of donor. Adult human and juvenile rat tooth papilla cells were implanted into surgically inactivated hair follicles within two different microenvironments. The human cells interacted with follicle epithelium to regenerate new end bulbs and create multiple differentiated hair fibers. Rodent tooth dental cells also induced new epithelial matrix structures and stimulated de novo hair formation. However, in many instances they also elicited mineralization and bone formation, a phenomenon that appeared to relate to their donor's age; the type of tooth of origin; and the host environment. Taken together, this study reveals that cultured dental papilla cells from postnatal mammals (adult, juvenile, and newborn) retain inductive molecular signals that must be common to both hair and teeth follicles. It highlights the stem cell-like qualities and morphogenetic abilities of tooth and hair follicle cells from mature humans, and their capacity for cross-appendage and interspecies communication and interaction. Besides the developmental implications, the present findings have relevance for stem cell biology, hair growth, tissue repair, and other biotechnologies. Moreover, the critical importance of considering the local microenvironment in which different cells/tissues are naturally or experimentally engineered is firmly demonstrated.