TGF-β2 and collagen play pivotal roles in the spheroid formation and anti-aging of human dermal papilla cells

Proanthocyanidin surface preconditioning of dental pulp stem cell spheroids enhances dimensional stability and biomineralization in vitro

AIM

Lack of adequate mechanical strength and progressive shrinkage over time remain challenges in scaffold-free microtissue-based dental pulp regeneration. Surface collagen cross-linking holds the promise to enhance the mechanical stability of microtissue constructs and trigger biological regulations. In this study, we proposed a novel strategy for surface preconditioning microtissues using a natural collagen cross-linker, proanthocyanidin (PA). We evaluated its effects on cell viability, tissue integrity, and biomineralization of dental pulp stem cell (DPSCs)-derived 3D cell spheroids.

METHODOLOGY

Microtissue and macrotissue spheroids were fabricated from DPSCs and incubated with PA solution for surface collagen cross-linking. Microtissue viability was examined by live/dead staining and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, with transverse dimension change monitored. Microtissue surface stiffness was measured by an atomic force microscope (AFM). PA-preconditioned microtissues and macrotissues were cultured under basal or osteogenic conditions. Immunofluorescence staining of PA-preconditioned microtissues was performed to detect dentin sialophosphoprotein (DSPP) and F-actin expressions. PA-preconditioned macrotissues were subjected to histological analysis, including haematoxylin-eosin (HE), alizarin red, and Masson trichrome staining. Immunohistochemistry staining was used to detect alkaline phosphatase (ALP) and dentin matrix acidic phosphoprotein 1 (DMP-1) expressions.

RESULTS

PA preconditioning had no adverse effects on microtissue spheroid viability and increased surface stiffness. It reduced dimensional shrinkage for over 7 days in microtissues and induced a larger transverse-section area in the macrotissue. PA preconditioning enhanced collagen formation, mineralized nodule formation, and elevated ALP and DMP-1 expressions in macrotissues. Additionally, PA preconditioning induced higher F-actin and DSPP expression in microtissues, while inhibition of F-actin activity by cytochalasin B attenuated PA-induced dimensional change and DSPP upregulation.

CONCLUSION

PA surface preconditioning of DPSCs spheroids demonstrates excellent biocompatibility while effectively enhancing tissue structure stability and promoting biomineralization. This strategy strengthens tissue integrity in DPSC-derived spheroids and amplifies osteogenic differentiation potential, advancing scaffold-free tissue engineering applications in regenerative dentistry.

Low Molecular Weight Collagen Peptide (LMWCP) Promotes Hair Growth by Activating the Wnt/GSK-3β/β-Catenin Signaling Pathway

Low molecular weight collagen peptide (LMWCP) is a collagen hydrolysate derived from fish. We investigated the effects of LMWCP on hair growth using human dermal papilla cells (hDPCs), human hair follicles (hHFs), patch assay, and telogenic C57BL/6 mice, while also examining the underlying mechanisms of its action. LMWCP promoted proliferation and mitochondrial potential, and the secretion of hair growth-related factors, such as EGF, HB-EGF, FGF-4, and FGF-6 in hDPCs. Patch assay showed that LMWCP increased the neogeneration of new HFs in a dose-dependent manner. This result correlated with an increase in the expression of dermal papilla (DP) signature genes such as, ALPL, SHH, FGF7, and BMP-2. LMWCP upregulated phosphorylation of glycogen synthase kinase-3β (GSK-3β) and β-catenin, and nuclear translocation of β-catenin, and it increased the expression of Wnt3a, LEF1, VEGF, ALP, and β-catenin. LMWCP promoted the growth of hHFs and increased the expression of β-catenin and VEGF. Oral administration of LMWCP to mice significantly stimulated hair growth. The expression of Wnt3a, β-catenin, PCNA, Cyclin D1, and VEGF was also elevated in the back skin of the mice. Furthermore, LMWCP increased the expression of cytokeratin and Keratin Type I and II. Collectively, these findings demonstrate that LMWCP has the potential to increase hair growth via activating the Wnt/β-catenin signaling pathway.

The Role of Mesenchymal Stem Cells in Hair Regeneration and Hair Cycle

The health of hair is directly related to people's health and appearance. Hair has key physiological functions, including skin protection and temperature regulation. Hair follicle (HF) is a vital mini-organ that directly impacts hair growth. Besides, various signaling pathways and molecules regulate the growth cycle transition of HFs. Hair and its regeneration studies have attracted much interest in recent years with the increasing rate of alopecia. Mesenchymal stem cells (MSCs), as pluripotent stem cells, can differentiate into fat, bone, and cartilage and stimulate regeneration and immunological regulation. MSCs have been widely employed to treat various clinical diseases, such as bone and cartilage injury, nerve injury, and lung injury. Besides, MSCs can be used for treatment of hair diseases due to their regenerative and immunomodulatory abilities. This review aimed to assess MSCs' treatment for alopecia, pertinent signaling pathways, and new material for hair regeneration in the last 5 years.

Clinical study on the efficacy and tolerability of a topical regenerative treatment in patients with telogen effluvium and mild androgenetic alopecia

Hair loss may change the quality of life since modern society considers hair an essential element in beauty definition. The most common causes of hair loss are androgenetic alopecia (AGA) and telogen effluvium (TE). AGA requires a lifetime use of minoxidil or finasteride (and sometimes they lose efficacy over the years), whereas TE has no standardized therapy available. Our study focuses on a novel topical regenerative preparation that, by mimicking autologous PRP, can safely and efficiently improve hair loss in patients affected by TE and AGA.

Discovery and Potential Functional Characterization of Long Noncoding RNAs Associated with Familial Acne Inversa with NCSTN Mutation

BACKGROUND

Long noncoding RNAs (lncRNAs) are associated with many dermatologic diseases. However, little is known about the regulatory function of lncRNAs in familial acne inversa (AI) patients with nicastrin (NCSTN) mutation.

OBJECTIVES

The aim of this study was to explore the regulatory function of lncRNAs in familial AI patients with NCSTN mutation.

METHODS

The expression profiles of lncRNAs and mRNAs in skin tissues from familial AI patients with NCSTN mutation and healthy individuals were analysed in this study via RNA sequencing (RNA-seq).

RESULTS

In total, 359 lncRNAs and 1,863 mRNAs were differentially expressed between the two groups. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses revealed that the dysregulated mRNAs targeted by lncRNAs were mainly associated with the immune regulation, Staphylococcus aureus infection and B cell receptor signalling pathways. The lncRNA-miRNA-mRNA coexpression network contained 265 network pairs comprising 55 dysregulated lncRNAs, 11 miRNAs, and 74 mRNAs. Conservation analysis of the differentially expressed lncRNAs between familial AI patients with NCSTN mutation and Ncstn keratinocyte-specific knockout (NcstnΔKC) mice identified 6 lncRNAs with sequence conservation; these lncRNAs may participate in apoptosis, proliferation, and skin barrier function.

CONCLUSIONS

These findings provide a direction for exploring the regulatory mechanisms underlying the progression of familial AI patients with NCSTN mutation.

Effective and economical cell therapy for hair regeneration

We reviewed and summarized the latest reports on the characteristics of stem cells and follicular cells that are under development for hair loss treatment. Compared with conventional medicine, cell therapy could be effective in the long term with a single treatment while having mild adverse effects. Adipose-derived stem cells (ASCs) have the advantages of easy access and large isolation amount compared with dermal papilla cells (DPCs) and dermal sheath cup cells (DSCs), and promote hair growth through the paracrine effect. ASCs have a poor potential in hair neogenesis, therefore, methods to enhance trichogenecity of ASCs should be developed. DSCs can be isolated from the peribulbar dermal sheath cup, while having immune tolerance, and hair inductivity. Therefore, DSCs were first developed and finished the phase II clinical trial; however, the hair growth was not satisfactory. Considering that a single injection of DSCs is effective for at least 9 months in the clinical setting, they can be an alternative therapy for hair regeneration. Though DPCs are not yet studied in clinical trials, we should pay attention to DPCs, as hair loss is associated with gradual reduction of DPCs and DP cell numbers fluctuate over the hair cycle. DPCs could make new hair follicles with epidermal cells, and have an immunomodulatory function to enable allogeneic transplantation. In addition, we can expand large quantities of DPCs with hair inductivity using spheroid culture, hypoxia condition, and growth factor supplement. 'Off-the-shelf' DPC therapy could be effective and economical, and therefore promising for hair regeneration.

Assessment of the anti-hair loss potential of Camellia japonica fruit shell extract in vitro

OBJECTIVE

Hair loss is caused by various factors. Impacts of these factors are often overlapped and intensified. Currently, mitigation of hair loss is being studied by proliferating dermal papilla cells (DPCs) and inhibiting deleterious factors such as dihydrotestosterone (DHT) and oxidative stress on hair growth. Camellia japonica (C. japonica) fruit shell is a discarded part. Its biological activity remains to be elucidated. In this study, we investigated the capacity of C. japonica fruit shell extract (CJFSE) for hair loss mitigation.

METHODS

MTT assay, spheroid culture and quantitative RT-PCR were performed to observe the proliferative effect of CJFSE on hair follicle dermal papilla cells (HFDPCs). Effects of CJFSE on DHT-induced hair loss were confirmed by Dkk-1 ELISA, β-galactosidase (β-gal) and 5α-reductase activity assay. In addition, effects of CJFSE on oxidative stress were confirmed through DPPH and ROS production assays.

RESULTS

CJFSE increased the proliferation and spheroid size of HFDPCs. Expression levels of VEGF-A, Wnt-1, c-Myc and Cyclin D1 were upregulated by CJFSE. CJFSE also suppressed 5α-reductase activity and DHT-induced decrease in cell proliferation, Dkk-1 secretion and β-gal activity. Moreover, CJFSE showed DPPH scavenging activity and ameliorated hydrogen peroxide-induced ROS production and β-gal activity. Finally, gallic acid and protocatechuic acid were observed in CJFSE through HPLC analysis.

CONCLUSION

CJFSE has the potential to alleviate hair loss by promoting hair cell growth and suppressing effects of DHT and oxidative stress on hair.

Silver nanoparticles induce developmental toxicity via oxidative stress and mitochondrial dysfunction in zebrafish (Danio rerio)

Sliver nanoparticles (AgNPs) are widely used in industry, agriculture, and medicine, potentially resulting in adverse effects on human health and aquatic environments. Here, we investigated the developmental toxicity of zebrafish embryos with acute exposure to AgNPs. Our results demonstrated developmental defects in 4 hpf zebrafish embryos after exposure to different concentrations of AgNPs for 72 h. In addition, RNA-seq profiling of zebrafish embryos after AgNPs treatment. Further Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that the differentially expressed genes (DEGs) were enriched in DNA replication initiation, oxidoreductase activity, DNA replication, cellular senescence, and oxidative phosphorylation signaling pathways in the AgNPs-treated group. Notably, we also found that AgNPs exposure could result in the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA), the inhibition of superoxide dismutase (SOD), catalase (CAT), and mitochondrial complex I-V activities, and the downregulated expression of SOD, CAT, and mitochondrial complex I-IV chain-related genes. Moreover, the expression of mitochondrion-mediated apoptosis signaling pathway-related genes, such as bax, bcl2, caspase-3, and caspase-9, was significantly regulated after AgNPs exposure in zebrafish. Therefore, these findings demonstrated that AgNPs exposure could cause oxidative stress, induce mitochondrial dysfunction, and ultimately lead to developmental toxicity.