Author Correction: The peptide AC 2 isolated from Bacillus-treated Trapa japonica fruit extract rescues DHT (dihydrotestosterone)-treated human dermal papilla cells and mediates mTORC1 signaling for autophagy and apoptosis suppression.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Antiaging Activity of Peptide Identified from Fermented Trapa Japonica Fruit Extract in Human Dermal Fibroblasts.

We have previously shown that Trapa japonica fruit extract (TJE) as well as its fermented extract (FTJ) can be potentially used to treat alopecia. In the current study, a newly synthesized peptide (PEP) was detected in an active compound isolated from FTJ. Several biological assays were conducted to verify the antiaging effects of TJE, FTJ, and PEP on the skin. We examined the effects of TJE, FTJ, and PEP on cell viability, collagen synthesis, and inhibition of mRNA expression of matrix metalloproteinases (MMPs), induced by tumor necrosis factor alpha (TNF-α), in human dermal fibroblasts (HDFs). In addition, a wound-healing assay of the human keratinocyte cell line (HaCaT) and a clinical study of antiaging activity were conducted. The findings confirmed that PEP exerted an effect on cell proliferation in a dose-dependent manner. Treatment with TJE, FTJ, and PEP increased collagen synthesis but inhibited TNF-α-induced mRNA expression of MMPs. Compared with TJE and FTJ, PEP promoted a significant level of wound recovery in HaCaT cells and also exhibited antiaging effect, as demonstrated by a clinical study. These results suggest that PEP shows potential as a skin antiaging cosmetic product.

The peptide AC 2 isolated from Bacillus-treated Trapa japonica fruit extract rescues DHT (dihydrotestosterone)-treated human dermal papilla cells and mediates mTORC1 signaling for autophagy and apoptosis suppression.

The Trapa japonica fruit is a natural plant growing in ponds with its roots in the mud. It has long been used as a home remedy for many diseases; however, a major problem with this kind of natural extract is the multicomponents-multitargets for diseases. Such problems make it difficult to identify the mechanism of action. Another problem is quality control and consistency. The aim of this research was to isolate a single bioactive compound (peptide) derived from the Trapa japonica fruit. The research was conducted with various experimental techniques, such as fermentation and liquid chromatography, to isolate a peptide. We isolated the AC 2 peptide from Trapa japonica fruit and found it to be promising on human dermal papilla cells. Dihydrotestosterone (DHT) stresses human dermal papilla cells and is a major cause of hair loss resulting from hormones and environmental factors. The purpose of this research was to develop an understanding of the mechanism by which the AC 2 peptide rescues dihydrotestosterone (DHT)-treated human dermal papilla cells. We explored the effects of the AC 2 peptide on the cell biological functions of human dermal papilla cells (HDPs). HDPs were treated with the AC 2 peptide and DHT. Then, a cytotoxicity assay, flow cytometry, Western blot, immunoprecipitation, and 3D cell culture for immunohistochemistry were conducted to investigate the mTORC1 pathway and suppression of autophagy and apoptosis. In addition, we also synthesized the AC2 peptide as an alternative to the expensive and difficult isolation and purification procedures and confirmed its potential in biomedical applications. We also validated the effects of the synthetic AC2 peptide as well as the isolated and purified AC2 peptide and established their similarity. Although extensive research has been carried out on natural extracts, few single studies have isolated and separated a bioactive peptide (single compound).

Bacillus/Trapa japonica Fruit Extract Ferment Filtrate enhances human hair follicle dermal papilla cell proliferation via the Akt/ERK/GSK-3ß signaling pathway.

BACKGROUND: Despite advances in medical treatments, the proportion of the population suffering from alopecia is increasing, creating a need for new treatments to control hair loss and prevent balding. Treatments based on plant-derived compounds could potentially prevent hair loss. Human hair follicle dermal papilla (HDP) cells, a type of specialized fibroblast in the hair bulb, play an essential role in controlling hair growth and in conditions such as androgenic alopecia. We examined the effect of Bacillus/Trapa japonica fruit ferment filtrate extracts (TJFs) on HDP cells to determine whether activation of the Akt/ERK/GSK-3ß signaling pathway improved HDP cell proliferation. METHODS: We prepared TJFs using various methods. The extract properties were analyzed using WST-1, Lowry, and cell migration assays as well as immunofluorescence staining. We also determined the cell cycle stage and performed western blotting and an in ovo chick chorioallantoic membrane assay. Last, we constructed an organotypic three-dimensional cell culture model for immunohistochemical use. RESULTS: Our study confirmed that the TJFs contained numerous peptides and five unknown fractions. The TJFs stimulated HDP cell proliferation and migration via the Akt/ERK/GSK-3ß signaling pathway. To verify that the Akt/ERK/GSK-3ß pathway affected HDP cell proliferation, we treated HDP cells with LY294002 (an Akt inhibitor), BIO (a GSK-3ß inhibitor), and PD98059 (an ERK inhibitor). The TJFs also induced cell cycle progression, inhibited type І 5α-reductase, decreased apoptosis, and enhanced angiogenesis (vascular expansion). In addition to these signaling pathways, proteins including insulin-like growth factor-1 and keratinocyte growth factor, stimulating hair growth, were detected in the three-dimensional cell culture model. CONCLUSIONS: Our results confirmed that TJFs enhance HDP cell proliferation via the Akt/ERK/GSK-3ß signaling pathway, suggesting a potential treatment for alopecia.

Chemicals that modulate stem cell differentiation.

Important cellular processes such as cell fate are likely to be controlled by an elaborate orchestration of multiple signaling pathways, many of which are still not well understood or known. Because protein kinases, the members of a large family of proteins involved in modulating many known signaling pathways, are likely to play important roles in balancing multiple signals to modulate cell fate, we focused our initial search for chemical reagents that regulate stem cell fate among known inhibitors of protein kinases. We have screened 41 characterized inhibitors of six major protein kinase subfamilies to alter the orchestration of multiple signaling pathways involved in differentiation of stem cells. We found that some of them cause recognizable changes in the differentiation rates of two types of stem cells, rat mesenchymal stem cells (MSCs) and mouse embryonic stem cells (ESCs). Among many, we describe the two most effective derivatives of the same scaffold compound, isoquinolinesulfonamide, on the stem cell differentiation: rat MSCs to chondrocytes and mouse ESCs to dopaminergic neurons.

Highly efficient and large-scale generation of functional dopamine neurons from human embryonic stem cells.

We developed a method for the efficient generation of functional dopaminergic (DA) neurons from human embryonic stem cells (hESCs) on a large scale. The most unique feature of this method is the generation of homogeneous spherical neural masses (SNMs) from the hESC-derived neural precursors. These SNMs provide several advantages: (i) they can be passaged for a long time without losing their differentiation capability into DA neurons; (ii) they can be coaxed into DA neurons at much higher efficiency than that from previous reports (86% tyrosine hydroxylase-positive neurons/total neurons); (iii) the induction of DA neurons from SNMs only takes 14 days; and (iv) no feeder cells are required during differentiation. These advantages allowed us to obtain a large number of DA neurons within a short time period and minimized potential contamination of unwanted cells or pathogens coming from the feeder layer. The highly efficient differentiation may not only enhance the efficacy of the cell therapy but also reduce the potential tumor formation from the undifferentiated residual hESCs. In line with this effect, we have never observed any tumor formation from the transplanted animals used in our study. When grafted into a parkinsonian rat model, the hESC-derived DA neurons elicited clear behavioral recovery in three behavioral tests. In summary, our study paves the way for the large-scale generation of purer and functional DA neurons for future clinical applications.

Efficient induction of oligodendrocytes from human embryonic stem cells.

Oligodendrocytes form myelin sheaths around axons to support rapid nerve conduction in the central nervous system (CNS). Damage to myelin can cause severe CNS disorders. In this study, we attempted to devise a protocol for the induction of oligodendrocytes from human embryonic stem (ES) cells to treat demyelinated axons. Four days after embryoid body formation, human ES cells were differentiated into neural precursors through selection and expansion procedures. Neural precursors were then grown in the presence of epidermal growth factor and then platelet-derived growth factor to generate oligodendrocyte precursor cells. After withdrawal of the growth factors, the cells were treated with thyroid hormone to induce differentiation into oligodendrocytes. This method resulted in approximately 81%-91% oligodendrocyte precursor cells and approximately 81% oligodendrocytes among total cells. The ability of the oligodendrocyte precursors to myelinate axons has been verified by coculturing with rat hippocampal neurons, confirming their biological functionality.