OBJECTIVE: To investigate the effectiveness and preliminary mechanisms of icariin (ICA) in enhancing the reparative effects of adipose-derived stem cells (ADSCs) on skin radiation damagies in rats. METHODS: Twelve SPF-grade Sprague Dawley rats [body weight (220±10) g] were subjected to a single dose of 10 Gy X-ray irradiation on a 1.5 cm×1.5 cm area of their dorsal skin, with a dose rate of 200 cGy/min to make skin radiation damage model. After successful modelling, the rats were randomly divided into 4 groups ( n=3), and on day 2, the corresponding cells were injected subcutaneously into the irradiated wounds: group A received 0.1 mL of rat ADSCs (1×10 ⁷cells/mL), group B received 0.1 mL of rat ADSCs (1×10 ⁷cells/mL)+1 μmol/L ICA (0.1 mL), group C received 0.1 mL of rat ADSCs (1×10 ⁷cells/mL) pretreated with a hypoxia-inducible factor 2α (HIF-2α) inhibitor+1 μmol/L ICA (0.1 mL), and group D received 0.1 mL of rat ADSCs (1×10 ⁷cells/mL) pretreated with a Notch1 inhibitor+1 μmol/L ICA (0.1 mL). All treatments were administered as single doses. The skin injury in the irradiated areas of the rats was observed continuously from day 1 to day 7 after modelling. On day 28, the rats were sacrificed, and skin tissues from the irradiated areas were harvested for histological examination (HE staining and Masson staining) to assess the repair status and for quantitative collagen content detection. Immunohistochemical staining was performed to detect CD31 expression, while Western blot and real-time fluorescence quantitative PCR (qRT-PCR) were used to measure the protein and mRNA relative expression levels of vascular endothelial growth factor (VEGF), platelet-derived growth factor BB (PDGF-BB), fibroblast growth factor 2 (FGF-2), interleukin 10 (IL-10), transforming growth factor β (TGF-β), HIF-2α, and Notch1, 2, and 3. RESULTS: All groups exhibited skin ulcers and redness after irradiation. On day 3, exudation of tissue fluid was observed in all groups. On day 7, group B showed significantly smaller skin injury areas compared to the other 3 groups. On day 28, histological examination revealed that the epidermis was thickened and the dermal fibers were slightly disordered with occasional inflammatory cell aggregation in group A. In group B, the epidermis appeared more normal, the dermal fibers were more orderly, and there was an increase in new blood vessels without significant inflammatory cell aggregation. In contrast, groups C and D showed significantly increased epidermal thickness, disordered and disrupted dermal fibers. Group B had higher collagen fiber content than the other 3 groups, and group D had lower content than group A, with significant differences ( P<0.05). Immunohistochemical staining showed that group B had significantly higher CD31 expression than the other 3 groups, while groups C and D had lower expression than group A, with significant differences ( P<0.05). Western blot and qRT-PCR results indicated that group B had significantly higher relative expression levels of VEGF, PDGF-BB, FGF-2, IL-10, TGF-β, HIF-2α, and Notch1, 2, and 3 proteins and mRNAs compared to the other 3 groups ( P<0.05). CONCLUSION ICA may enhance the reparative effects of ADSCs on rat skin radiation damage by promoting angiogenesis and reducing inflammatory responses through the HIF-2α-VEGF-Notch signaling pathway.
Animals ; Rats, Sprague-Dawley ; Skin/pathology* ; Rats ; Vascular Endothelial Growth Factor A/genetics* ; Basic Helix-Loop-Helix Transcription Factors/genetics* ; Signal Transduction ; Flavonoids/pharmacology* ; Adipose Tissue/cytology* ; Stem Cells/cytology* ; Receptors, Notch/metabolism* ; Radiation Injuries, Experimental/metabolism* ; Wound Healing/drug effects* ; Male

Frostbite is the most common cold injury and is caused by both immediate cold-induced cell death and the gradual development of localized inflammation and tissue ischemia. Delayed healing of frostbite often leads to scar formation, which not only causes psychological distress but also tends to result in the development of secondary malignant tumors. Therefore, a rapid healing method for frostbite wounds is urgently needed. Herein, we used a mouse skin model of frostbite injury to evaluate the recovery process after frostbite. Moreover, single-cell transcriptomics was used to determine the patterns of changes in monocytes, macrophages, epidermal cells, and fibroblasts during frostbite. Most importantly, human-induced pluripotent stem cell (hiPSC)-derived skin organoids combined with gelatin-hydrogel were constructed for the treatment of frostbite. The results showed that skin organoid treatment significantly accelerated wound healing by reducing early inflammation after frostbite and increasing the proportions of epidermal stem cells. Moreover, in the later stage of wound healing, skin organoids reduced the overall proportions of fibroblasts, significantly reduced fibroblast-to-myofibroblast transition by regulating the integrin α5β1-FAK pathway, and remodeled the extracellular matrix (ECM) through degradation and reassembly mechanisms, facilitating the restoration of physiological ECM and reducing the abundance of ECM associated with abnormal scar formation. These results highlight the potential application of organoids for promoting the reversal of frostbite-related injury and the recovery of skin functions. This study provides a new therapeutic alternative for patients suffering from disfigurement and skin dysfunction caused by frostbite.
Animals ; Organoids/metabolism* ; Mice ; Humans ; Wound Healing ; Frostbite/metabolism* ; Skin/pathology* ; Induced Pluripotent Stem Cells/cytology* ; Cicatrix/pathology* ; Fibroblasts/metabolism* ; Disease Models, Animal ; Mice, Inbred C57BL ; Extracellular Matrix/metabolism* ; Male

Chronic non-healing wounds significantly impair patient rehabilitation and remain a critical clinical challenge. Stem cell-derived exosomes, owing to their biocompatibility and physiological activity, have emerged as a promising therapeutic approach in regenerative medicine. Beyond their intrinsic wound-healing properties, exosomes are increasingly explored as carriers for small-molecule drugs to enhance synergistic treatment effects. Although microRNAs (miRNAs) exhibit potential in promoting cell proliferation and re-epithelialization, their clinical application is hindered by poor stability. In this study, we investigated the therapeutic effects of miR-132-3p-loaded human umbilical mesenchymal stem cell-derived exosomes (miR-132-3p@UMSC-EXOs) on human foreskin fibroblast-1 (HFF-1). Our findings demonstrated that miR-132-3p@UMSC-EXOs significantly enhanced proliferation and migration of HFF-1, while reducing intracellular reactive oxygen species (ROS) levels compared with unloaded exosomes. Furthermore, qRT-PCR and Western blotting analyses revealed that miR-132-3p@UMSC-EXOs modulated the expression of genes associated with extracellular matrix (ECM) remodeling and inflammation, suggesting their potential to upregulate collagen synthesis and improve ECM metabolism. These results highlight the therapeutic promise of miR-132-3p@UMSC-EXOs in accelerating wound healing.
Humans ; MicroRNAs/pharmacology* ; Exosomes/metabolism* ; Mesenchymal Stem Cells/cytology* ; Wound Healing ; Umbilical Cord/cytology* ; Cell Proliferation ; Fibroblasts/cytology* ; Skin/injuries* ; Cell Movement ; Reactive Oxygen Species/metabolism* ; Cells, Cultured

Objective To investigate the effect of liquid-liquid phase separation(LLPS)of YTH domain family protein 2(YTHDF2)on the sodium arsenite-induced malignant transformation of skin cells,providing a new intervention target for the prevention and control of sodium arsenite-induced carcinogenesis.Methods The HaCaT cell model of malignant transformation was constructed by continuous treatment with 1 μmol/L sodium arsenite for 22 weeks,including cells with normal YTHDF2 LLPS(YTHDF2-wt)and cells with inhibited YTHDF2 LLPS(YTHDF2-mut).Confocal microscopy was employed to observe and characterize the LLPS droplets formed by YTHDF2 during sodium arsenite-induced malignant transformation of skin cells.Cell proliferation,scratch healing,and colony formation assays were performed to detect malignant phenotypes.Western blotting,quantitative reverse transcription PCR,and immunofluorescence experiments were conducted to examine the effects of YTHDF2 LLPS on the mRNA and protein levels of phosphatase and tensin homolog deleted on chromosome ten(PTEN)during sodium arsenite-induced malignant transformation of skin cells.Results After 4 weeks of sodium arsenite treatment,LLPS droplets of YTHDF2 appeared in YTHDF2-wt cells,and the number of droplets gradually increased as the treatment time was prolonged(F=35.252,P<0.001),while no phase-separated droplets were observed in YTHDF2-mut cells.Compared with YTHDF2-mut cells,YTHDF2-wt cells showed enhanced proliferation at the time points of 48 h(t=3.654,P=0.006)and 72 h(t=5.458,P<0.001)after 22 weeks of sodium arsenite treatment.The scratch healing rate of YTHDF2-wt cells was increased at the 8th(t=12.137,P<0.001)and 22th(t=4.484,P=0.011)weeks of sodium arsenite treatment.The number of colonies formed by YTHDF2-wt cells was higher at the 4th(t=3.365,P=0.027),8th(t=5.580,P=0.005),and 22th(t=3.328,P=0.029)weeks of sodium arsenite treatment.Compared with YTHDF2-mut cells,YTHDF2-wt cells showed down-regulated protein(t=-3.119,P=0.036)and mRNA(t=4.051,P=0.015) levels of PTEN after 22 weeks of sodium arsenite treatment.Immunofluorescence results showed that after 4 weeks of sodium arsenite treatment,YTHDF2 LLPS droplets in YTHDF2-wt cells were localized to stress granules,translation-related membrane-less organelles.Conclusions During sodium arsenite-induced malignant transformation of skin cells,YTHDF2 undergoes LLPS and localizes to stress granules,translation-related membrane-less organelles.YTHDF2 LLPS participates in sodium arsenite-induced malignant transformation of skin cells by down-regulating the mRNA level of the key tumor suppressor PTEN.
Arsenites/toxicity* ; Sodium Compounds/toxicity* ; Humans ; Cell Transformation, Neoplastic/drug effects* ; PTEN Phosphohydrolase/metabolism* ; Cell Proliferation ; Skin/cytology* ; RNA-Binding Proteins ; Skin Neoplasms/chemically induced* ; Cell Line

OBJECTIVESTo investigate the hair growth-promoting effect of Miscanthus sinensis var. purpurascens (MSP) flower extracton on in vitro and in vivo models.

METHODSMSP flower extract was extracted in 99.9% methanol and applied to examine the proliferation of human dermal papilla cells (hDPCs) in vitro at the dose of 3.92-62.50 μg/mL and hair growth of C57BL/6 mice in vivo at the dose of 1000 μg/mL. The expression of transforming growth factor β1 (TGF-β1), hepatocyte growth factor (HGF), β-catenin, substance P was measured by relative quantitative realtime polymerase chain reaction. Histopathological and immunohistochemical analysis were performed.

RESULTSMSP (7.81 μg/mL) down-regulated TGF-β1 and up-regulated HGF and β-catenin in hDPCs (P<0.01). MSP (1000 μg/mL)-treated mice showed the earlier transition of hair follicles from the telogen to the anagen phase. The number of mast cells was lower in the MSP-treated mice than in other groups (P<0.05 vs. NCS group). Substance P and TGF-β1 were expressed in hair follicles and skin of the MSP group lower than that in negative control. Stem cell factor in hair follicles was up-regulated in the MSP-treated mice (P<0.01).

CONCLUSIONSThe MSP flower extract may have hair growth-promotion activities.

Animals ; Antioxidants ; pharmacology ; Cell Count ; Cell Proliferation ; drug effects ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Female ; Flowers ; chemistry ; Hair Follicle ; cytology ; drug effects ; growth & development ; Hepatocyte Growth Factor ; metabolism ; Humans ; Mast Cells ; cytology ; Mice, Inbred C57BL ; Phosphorylation ; drug effects ; Plant Extracts ; pharmacology ; Poaceae ; chemistry ; RNA, Messenger ; genetics ; metabolism ; Skin ; metabolism ; Stem Cell Factor ; metabolism ; Stress, Psychological ; pathology ; Substance P ; metabolism ; Transforming Growth Factor beta ; genetics ; metabolism ; Vascular Endothelial Growth Factor A ; genetics ; metabolism ; beta Catenin ; metabolism

BACKGROUNDCathepsin L (CatL) is a cysteine protease with strong matrix degradation activity that contributes to photoaging. Mannose phosphate-independent sorting pathways mediate ultraviolet A (UVA)-induced alternate trafficking of CatL. Little is known about signaling pathways involved in the regulation of UVA-induced CatL expression and activity. This study aims to investigate whether a single UVA irradiation affects CatL expression and activity and whether mitogen-activated protein kinase (MAPK)/activator protein-1 (AP-1) pathway is involved in the regulation of UVA-induced CatL expression and activity in human dermal fibroblasts (HDFs).

METHODSPrimary HDFs were exposed to UVA. Cell proliferation was determined by a cell counting kit. UVA-induced CatL production and activity were studied with quantitative real-time reverse transcription polymerase chain reaction (RT-PCR), Western blotting, and fluorimetric assay in cell lysates collected on three consecutive days after irradiation. Time courses of UVA-activated JNK and p38MAPK signaling were examined by Western blotting. Effects of MAPK inhibitors and knockdown of Jun and Fos on UVA-induced CatL expression and activity were investigated by RT-PCR, Western blotting, and fluorimetric assay. Data were analyzed by one-way analysis of variance.

RESULTSUVA significantly increased CatL gene expression, protein abundance, and enzymatic activity for three consecutive days after irradiation (F = 83.11, 56.14, and 71.19, respectively; all P < 0.05). Further investigation demonstrated phosphorylation of JNK and p38MAPK activated by UVA. Importantly, inactivation of JNK pathway significantly decreased UVA-induced CatL expression and activity, which were not affected by p38MAPK inhibition. Moreover, knockdown of Jun and Fos significantly attenuated basal and UVA-induced CatL expression and activity.

CONCLUSIONSUVA enhances CatL production and activity in HDFs, probably by activating JNK and downstreaming AP-1. These findings provide a new possible molecular approach for antiphotoaging therapy.

Anthracenes ; pharmacology ; Cathepsin L ; metabolism ; Cells, Cultured ; Child ; Child, Preschool ; Enzyme Inhibitors ; pharmacology ; Extracellular Signal-Regulated MAP Kinases ; antagonists & inhibitors ; Fibroblasts ; cytology ; drug effects ; metabolism ; radiation effects ; Humans ; Imidazoles ; pharmacology ; MAP Kinase Signaling System ; drug effects ; radiation effects ; Oncogene Proteins v-fos ; genetics ; metabolism ; Proto-Oncogene Proteins c-jun ; genetics ; metabolism ; Pyridines ; pharmacology ; Skin ; cytology ; Ultraviolet Rays

OBJECTIVETo observe the effect of solar infrared ray (IR) radiation on the expressions of c-Jun and collagens I and III in cultured human skin fibroblasts (HSFs) and explore the molecular mechanism by which IR radiation causes aging of the skin.

METHODSPrimarily cultured HSFs exposed to IR radiation were examined for changes of the cell viability with MTT assay. The mRNA and protein expressions of c-Jun and collagens I and III was detected with real-time quantitative PCR and immunocytochemistry.

RESULTSMTT assay showed that IR irradiation caused inhibition of cell proliferation compared with the control cells. The mRNA and protein expression of collagen I was decreased significantly by IR irradiation with the increase of the irradiation dose (P<0.01). HSFs irradiated by IR for 12 h showed a dose-dependent reduction of the expression of collagen type III mRNA and protein (P<0.05, P<0.01), but the expression increased dose-dependently in response to IR exposure for 24 h (P<0.05 or 0.01). IR irradiation enhanced the mRNA and protein expression of c-Jun in a dose-dependence manner (P<0.05 or 0.01).

CONCLUSIONSIR irradiation can increase the expression of c-Jun, inhibit the expression of collagen I, and cause disturbance in collagen III expression in human skin fibroblasts, which may be one of the mechanism of IR radiation to initiate and promote skin photoaging.

Cell Proliferation ; Cell Survival ; Cells, Cultured ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Fibroblasts ; metabolism ; radiation effects ; Humans ; Infrared Rays ; Proto-Oncogene Proteins c-jun ; metabolism ; RNA, Messenger ; metabolism ; Skin ; cytology ; Skin Aging ; Ultraviolet Rays

To determine whether platelet-rich fibrin lysate (PRF-L) could restore the function of chronically ultraviolet-A (UVA)-irradiated human dermal fibroblasts (HDFs), we isolated and sub-cultured HDFs from six different human foreskins. HDFs were divided into two groups: those that received chronic UVA irradiation (total dosages of 10 J cm-2) and those that were not irradiated. We compared the proliferation rates, collagen deposition, and migration rates between the groups and between chronically UVA-irradiated HDFs in control and PRF-L-treated media. Our experiment showed that chronic UVA irradiation significantly decreased (p<0.05) the proliferation rates, migration rates, and collagen deposition of HDFs, compared to controls. Compared to control media, chronically UVA-irradiated HDFs in 50% PRF-L had significantly increased proliferation rates, migration rates, and collagen deposition (p<0.05), and the migration rates and collagen deposition of chronically UVA-irradiated HDFs in 50% PRF-L were equal to those of normal fibroblasts. Based on this experiment, we concluded that PRF-L is a good candidate material for treating UVA-induced photoaging of skin, although the best method for its clinical application remains to be determined.
Blood Platelets/*cytology/*metabolism ; Cell Movement/radiation effects ; Cell Proliferation/radiation effects ; Cells, Cultured ; Collagen/metabolism ; Fibrin/*metabolism ; Fibroblasts/*cytology/metabolism/*radiation effects ; Humans ; Skin/*cytology ; Time Factors ; Ultraviolet Rays/*adverse effects

Skin wound healing is a complex event, and interrupted wound healing process could lead to scar formation. The aim of this study was to examine the morphological changes of scar tissue. Pathological staining (HE staining, Masson's trichrome staining, methenamine silver staining) was used to evaluate the morphological changes of regenerating epidermis in normal skin and scar tissue, and immunofluorescence staining to detect the expression of collagen IV, a component of basement membrane (BM), and the expression of integrinβ4, a receptor for BM laminins. Additionally, the expression of CK14, CK5, and CK10 was measured to evaluate the proliferation and differentiation of keratinocytes in normal skin and scar tissue. The results showed that the structure of the skin was histologically changed in scar tissue. Collagen IV, expressed under the epidermis of normal skin, was reduced distinctly in scar tissue. Integrinβ4, expressed in the basal layer of normal skin, was found absent in the basal layer of scar tissue. Additionally, it was found that keratinocytes in scarring epidermis were more proliferative than in normal skin. These results indicate that during the skin wound healing, altered formation of BM may affect the proliferation of keratinocytes, reepithelial and tissue remodeling, and then result in scar formation. Thus, remodeling BM structure during wound repair may be beneficial for improving healing in cutaneous wounds during clinical practice.
Adolescent ; Adult ; Cicatrix ; metabolism ; pathology ; Collagen Type IV ; metabolism ; Female ; Humans ; Integrin beta4 ; metabolism ; Keratinocytes ; cytology ; metabolism ; pathology ; Male ; Skin ; cytology ; metabolism ; pathology

BACKGROUNDShikonin is a major active chemical component extracted from Lithospermi Radix, an effective traditional herb in various types of wound healing. Shikonin can accelerate granulomatous tissue formation by the rat cotton pellet method and induce neovascularization in granulomatous tissue. The purpose of the study was to investigate its mechanism of action in human skin cells.

METHODSMTS assay was used to measure cell growth. The collagen type I (COL1 ) mRNA expression and procollagen type I C-peptide (PIP) production were detected by real-time quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Immunofluorescence and western blot analyses were carried out to investigate nuclear factor-κB (NF-κB) signaling pathway. Cell-based proteasome activity assay was used to determine proteasome activity.

RESULTSIn this study, we found that 10 μmol/L shikonin stimulated the growth of normal human keratinocytes and 1 μmol/L shikonin promoted growth of human dermal fibroblasts. However, shikonin did not directly induce COL1 mRNA expression and PIP production in dermal fibroblasts in vitro. In addition, 1 μmol/L shikonin inhibited translocation of NF-κB p65 from cytoplasm to nucleus induced by tumor necrosis factor-α stimulation in dermal fibroblasts. Furthermore, shikonin inhibited chymotrypsin-like activity of proteasome and was associated with accumulation of phosphorylated inhibitor κB-α in dermal fibroblasts.

CONCLUSIONSThese results suggested that shikonin may promote wound healing via its cell growth promoting activity and suppress skin inflammation via inhibitory activity on proteasome. Thus, shikonin may be a potential therapeutic reagent both in wound healing and inflammatory skin diseases.

Cell Proliferation ; drug effects ; Cells, Cultured ; Enzyme-Linked Immunosorbent Assay ; Fibroblasts ; drug effects ; Humans ; Keratinocytes ; drug effects ; NF-kappa B ; metabolism ; Naphthoquinones ; pharmacology ; Polymerase Chain Reaction ; Proteasome Endopeptidase Complex ; drug effects ; Skin ; cytology