Wound Healing Effect of Gintonin Involves Lysophosphatidic Acid Receptor/Vascular Endothelial Growth Factor Signaling Pathway in Keratinocytes

Hydroxysafflor Yellow A Promotes HaCaT Cell Proliferation and Migration by Regulating HBEGF/EGFR and PI3K/AKT Pathways and Circ_0084443

OBJECTIVE

To investigate the effect and possible mechanism of hydroxysafflor yellow A (HSYA) on human immortalized keratinocyte cell proliferation and migration.

METHODS

HaCaT cells were treated with HSYA. Cell proliferation was detected by the cell counting kit-8 assay, and cell migration was measured using wound healing assay and Transwell migration assay. The mRNA and protein expression levels of heparin-binding epidermal growth factor (EGF)-like growth factor (HBEGF), EGF receptor (EGFR), phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), mammalian target of rapamycin (mTOR), and hypoxia-inducible factor-1α (HIF-1α) were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot, respectively. Circ_0084443-overexpressing HaCaT cells and empty plasmid HaCaT cells were constructed using the lentiviral stable transfection and treated with HSYA. The expression of circ_0084443 was detected by qRT-PCR.

RESULTS

HSYA (800 µmol/L) significantly promoted HaCaT cell proliferation and migration (P<0.05 or P<0.01). It also increased the mRNA and protein expression levels of HBEGF, EGFR, PI3K, AKT, mTOR and HIF-1α, and increased the phosphorylation levels of PI3K and AKT (P<0.05 or P<0.01). Furthermore, HSYA promoted HaCaT cell proliferation and migration via the HBEGF/EGFR and PI3K/AKT/mTOR signaling pathways (P<0.01). Circ_0084443 attenuated the mRNA expression levels of HBEGF, EGFR, PI3K, AKT, mTOR and HIF-1α (P<0.05). HSYA inhibited the circ_0084443 expression, further antagonized the inhibition of circ_0084443 on HBEGF, EGFR, PI3K, AKT, mTOR and HIF-1α, and promoted the proliferation of circ_0084443-overexpressing HaCaT cells (P<0.05 or P<0.01). However, HSYA could not influence the inhibitory effect of circ_0084443 on HaCaT cell migration (P>0.05).

CONCLUSION

HSYA played an accelerative role in HaCaT cell proliferation and migration, which may be attributable to activating HBEGF/EGFR and PI3K/AKT signaling pathways, and had a particular inhibitory effect on the keratinocyte negative regulator circ_0084443.

Gintonin-Induced Wound-Healing-Related Responses Involve Epidermal-Growth-Factor-like Effects in Keratinocytes

Epidermal growth factor (EGF) receptor activation and related downstream signaling pathways are known to be one of the major mechanisms of the proliferation and migration of keratinocytes. The heparin-binding EGF-like growth factor (HB-EGF) binds to EGF receptors and stimulates keratinocyte proliferation and migration. Gintonin, a novel ginseng compound, is a lysophosphatidic acid (LPA) receptor ligand. Gintonin has skin-wound-healing effects. However, the underlying mechanisms for these gintonin actions remain unclear. In this study, we aimed to elucidate the involvement of EGFRs in gintonin-induced wound repair in HaCaT keratinocytes. In this study, a water-soluble tetrazolium salt-based assay, a modified Boyden chamber migration assay, and immunoblotting were performed. Gintonin increased EGF receptor activation in HaCaT cells. However, the gintonin-induced phosphorylation of the EGF receptor was markedly reduced via treatment with the LPA inhibitor Ki16425 or the EGF receptor inhibitor erlotinib. Gintonin-enhanced proliferation and migration were blocked by the EGF receptor inhibitors (erlotinib and AG1478). Additionally, gintonin stimulated the expression and release of HB-EGF in HaCaT cells. EGF receptor inhibitors blocked gintonin-enhanced HB-EGF expression. These results indicate that the wound-healing effects of gintonin are closely related to the collaboration between EGF receptor activation and HB-EGF release-mediated downstream signaling pathways.

N,N-Dimethylglycine Sodium Salt Exerts Marked Anti-Inflammatory Effects in Various Dermatitis Models and Activates Human Epidermal Keratinocytes by Increasing Proliferation, Migration, and Growth Factor Release

N,N-dimethylglycine (DMG) is a naturally occurring compound being widely used as an oral supplement to improve growth and physical performance. Thus far, its effects on human skin have not been described in the literature. For the first time, we show that N,N-dimethylglycine sodium salt (DMG-Na) promoted the proliferation of cultured human epidermal HaCaT keratinocytes. Even at high doses, DMG-Na did not compromise the cellular viability of these cells. In a scratch wound-closure assay, DMG-Na augmented the rate of wound closure, demonstrating that it promotes keratinocyte migration. Further, DMG-Na treatment of the cells resulted in the upregulation of the synthesis and release of specific growth factors. Intriguingly, DMG-Na also exerted robust anti-inflammatory and antioxidant effects, as assessed in three different models of human keratinocytes, mimicking microbial and allergic contact dermatitis as well as psoriasis and UVB irradiation-induced solar dermatitis. These results identify DMG-Na as a highly promising novel active compound to promote epidermal proliferation, regeneration, and repair, and to exert protective functions. Further preclinical and clinical studies are under investigation to prove the seminal impact of topically applied DMG-Na on relevant conditions of the skin and its appendages.

Preparation of Red Ginseng Marc-Derived Gintonin and Its Application as a Skin Nutrient

Ginseng is one of the traditional herbal medicines for tonic. Gintonin is a new material derived from white/red ginseng and its lysophosphatidic acids (LPAs) play as a ligand for G protein-coupled LPA receptors. Korean red ginseng marc (KRGM) is a by-product after the KRG processes. We developed a low-cost/high-efficiency method for KRGM gintonin production. We further studied the KRGM gintonin-mediated anti-skin aging effects under UVB exposure using human dermal fibroblasts (HDFs). KRGM gintonin yield is about 8%. KRGM gintonin contains a high amount of LPA C_18:2, lysophosphatidylcholine (LPC), and phosphatidylcholine (PC), which is similar to white ginseng gintonin. KRGM gintonin induced [Ca²⁺]_i transient via LPA1/3 receptors and increased cell viability/proliferation under UVB exposure. The underlying mechanisms of these results are associated with the antioxidant action of KRGM gintonin. KRGM gintonin attenuated UVB-induced cell senescence by inhibiting cellular β-galactosidase overexpression and facilitated wound healing. These results indicate that KRGM can be a novel bioresource of KRGM gintonin, which can be industrially utilized as new material for skin nutrition and/or skin healthcare.

Extraction Optimization, Characterization and Biological Activities of Polysaccharide Extracts from Nymphaea hybrid

In this study, polysaccharide-rich Nymphaea hybrid extracts (NHE) were obtained using the ultrasound-assisted cellulase extraction (UCE) method optimized by response surface methodology (RSM). The structural properties and thermal stability of NHE were characterized by Fourier-transform infrared (FT-IR), high-performance liquid chromatography (HPLC) and thermogravimetry-derivative thermogravimetry (TG-DTG) analysis, respectively. Moreover, the bioactivities of NHE, including the antioxidant, anti-inflammatory, whitening and scratch healing activities were evaluated by different in vitro assays. NHE conveyed a good ability to scavenge against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals and inhibit the hyaluronidase activity. NHE can effectively protect the HaCaT cells against oxidative damage by inhibiting the intracellular reactive oxygen species (ROS) production in the H₂O₂ stimulation assays and promoting the proliferation and migration in the scratch assays. In addition, NHE was proven to inhibit melanin production in B16 cells. Collectively, the above results seem to be the evidence needed to promote the potential of NHE to be regarded as a new functional raw material in the cosmetics or food industries.

Gintonin Isolated from Ginseng Inhibits the Epithelial-Mesenchymal Transition Induced by TGF-β in A549 Lung Cancer Cells

Epithelial-to-mesenchymal transition (EM transition) is a process wherein epithelial cells lose their intrinsic characteristics and cell-cell junctions and differentiate into a mesenchymal phenotype. EM transition is an important feature of cancer invasion and metastasis. In this study, we aimed to investigate the inhibitory effect of gintonin (GT), an ingredient of ginseng, on EM transition using A549 cells. The proliferation of A549 cells was enhanced following treatment with 50, 75, and 100 μg/mL of GT. GT affected EM transition-induced gene and protein expression, specifically that of vimentin (Vim), N-cadherin (N-cad), zinc finger E-box-binding homeobox 1, and Twist in A549 cells. Furthermore, the transforming growth factor beta 1 (TGF-β1)-induced phosphorylation of Smad2 and Smad3 was suppressed by GT treatment. Immunofluorescence staining also showed that GT treatment decreased the TGF-β1-induced expression of Vim and N-cad in A549 cells. Therefore, GT may be used to suppress cancer cell metastasis via maintenance of the cell-cell junction's integrity. However, further studies are required to pave the way for its translation into clinical application in cancer therapeutics.

Nanoliposomal peptides derived from Spirulina platensis protein accelerate full-thickness wound healing

Spirulina platensis is a type of blue-green algae that contains large amounts of protein with therapeutic effects. The present study was performed to investigate the effects of encapsulated Spirulina protein hydrolysates (SPH) with nanoliposomes (NLPs) in reducing wound healing period. SPH-loaded NLPs showed the size and zeta potential of 158 nm and -48 mV, respectively; as well as a uniform non-aggregated morphology. In-vitro MTT toxicity studies on the Human Foreskin Fibroblast (HFFF-2) cell line exhibited that the hydrolyzed peptides had no toxic effect and increased cell growth. The scratch test confirmed the MTT results. For in-vivo study, 162 mice were divided into nine groups, including the mice groups treated with blank gel, blank NLPs, and those treated with 2.5, 5, and 10 % SPH and SPH-loaded NLPs. The histopathological assessment was done to investigate rate of fibroblast proliferation and epithelialization. Immunofluorescence staining for bFGF, CD31, COL1A was conducted. The results showed that the mice group treated with SPH-NLPs showed higher wound contraction, epithelization, fibroblast proliferation, and higher expressions for bFGF, CD31, COL1A compared with blanks and other groups. In conclusion, the derived and encapsulated peptides showed significant effects in accelerating wound healing via angiogenesis and collagen production.

Effect of Taspine hydrochloride on the repair of rat skin wounds by regulating keratinocyte growth factor signal

To explore the regulation of keratinocyte growth factor (KGF) in the process of repairing rat skin wounds by taspine hydrochloride (TA/HCl), 45 male Sprague-Dawley (SD) rats were purchased and divided into an experimental group, a dimethyl sulfoxide (DMSO) control group, and a basic fibroblast growth factor (bFGF) control group, each with 15 only. A back trauma model was innovatively adopted to prevent rats from biting and contaminating. The wound healing time and healing rate of the rat, and the Hydroxyproline (Hyp) and KGF expressions were observed. Morphological changes of wound tissue and the number of capillaries were observed after hematoxylin-eosin (HE) staining. The results showed that wound healing rate of experimental group and bFGF group was significantly higher than that of DMSO group (P < 0.05) after 2–15 days, and wound healing time of experimental group was 18 days, which was significantly lower than that of the DMSO group (P < 0.05). Expression levels of Hyp and KGF in the granulation tissue of rats in the experimental group were much higher than those in the DMSO control group after trauma (P < 0.05). In early stage of wound tissue repair, the number of new capillaries formed in experimental group was significantly higher than that in DMSO control group (P < 0.05). In summary, this study innovatively focused on KGF. The mechanism of TA/HCL promoting rat skin wound healing was closely related to KGF.