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

Objective To investigate the effects of cucurbitacin B (CucB) on alleviating skin lesions and inflammation in psoriasis mice via the cGAS-STING signaling pathway. Methods The expression of genes associated with the cGAS-STING signaling pathway in psoriatic lesions and non-lesional skin was analyzed, and hallmark gene set enrichment analysis was performed. The cytotoxicity of CucB on BMDMs was evaluated using the CCK-8 assay. The expression levels of genes and proteins related to the cGAS-STING signaling pathway, along with the secretion of inflammatory cytokines, were measured at different concentrations of CucB using quantitative PCR, Western blotting, and ELISA. Imiquimod-induced psoriasis BALB/c mice were divided into four groups: normal group, model group, low-dose CucB group [0.1 mg/ (kg.d)], and high-dose CucB group [0.4 mg/ (kg.d)], with five mice per group. PASI scoring was performed to assess the severity of psoriasis after 6 days of treatment, and HE staining was conducted to observe pathological damage. Meanwhile, the mRNA levels of inflammatory cytokines and their secretion were detected by qPCR and ELISA. Results Most cGAS-STING signaling-related genes were upregulated in lesional skin of psoriasis patients, and the hallmark gene set enrichment analysis revealed that the most significantly upregulated genes were primarily associated with immune response signaling pathways. CucB inhibited dsDNA-induced phosphorylation of interferon regulatory factor 3 (IRF3) and STING proteins in both bone-marrow derived macrophages(BMDMs) and THP-1 cells. CucB also suppressed dsDNA-induced mRNA expression of IFNB1, TNF, IFIT1, CXCL10, ISG15, and reduced the secretion of cytokines such as IFN-β, IL-1β, and TNF-α in THP-1 cells. In the imiquimod-induced psoriasis mouse model, CucB treatment reduced psoriatic symptoms, alleviated skin lesions, and attenuated inflammation. ELISA and qPCR results showed that CucB significantly reduced serum secretion levels of IL-6, TNF-α, and IL-1β, as well as the mRNA levels of IL23A, IL1B, IL6, TNF, and IFNB1. Conclusion CucB inhibits cytoplasmic DNA-induced activationc of the GAS-STING pathway. CucB significantly attenuates skin lesions and inflammation in IMQ-induced psoriatic mice, and the potential molecular mechanism may be related to the down-regulation of the cGAS-STING pathway.
Animals ; Psoriasis/pathology* ; Signal Transduction/drug effects* ; Membrane Proteins/genetics* ; Mice ; Nucleotidyltransferases/genetics* ; Disease Models, Animal ; Mice, Inbred BALB C ; Skin/metabolism* ; Triterpenes/therapeutic use* ; Humans ; Cytokines/metabolism* ; Inflammation/drug therapy* ; Male

Skin fibrosis is primarily characterized by excessive fibroblasts proliferation and aberrant extracellular matrix accumulation, leading to pathological conditions such as hypertrophic scars, keloids, and systemic sclerosis. This dynamic and complex process involves intricate interactions among various resident skin cells and inflammatory cells, ultimately resulting in extracellular matrix deposition and even invasive growth. The maintenance of cellular phenotypes and functions relies on dynamic metabolic responses, and cellular signal transduction is closely coupled with metabolic processes. Given that the coupling of cell metabolism and signaling in the skin fibrosis microenvironment plays a critical role in inflammatory responses and fibrotic activation, modulation of these metabolic pathways may offer novel therapeutic strategies for inhibiting or even reversing the progression of skin fibrosis. This review systematically summarizes the metabolic characteristics of various cell types involved in skin fibrosis, with a focus on core metabolic reprogramming mechanisms such as hyperactive glycolysis, dysregulated fatty acid metabolism, cellular metabolic dysfunction and dysregulated mTOR/AMPK signaling. Furthermore, potential intervention strategies targeting these metabolic pathways are explored, thereby providing new research perspectives for the treatment of skin fibrosis.
Humans ; Fibrosis/metabolism* ; Skin/metabolism* ; Signal Transduction ; Fibroblasts/pathology* ; TOR Serine-Threonine Kinases/metabolism* ; Skin Diseases/pathology* ; Cellular Reprogramming ; Metabolic Reprogramming

OBJECTIVE: It has been reported that the mRNA expression of serine protease 23 (PRSS23) was increased in skin fibroblasts from systemic sclerosis patients (SSc). The purpose of this study is to explore the pathogenetic effect and mechanism of PRSS23 in skin fibrosis of SSc. METHODS: The expression of PRSS23 in skin tissues from the SSc patients and healthy controls was detected by immunohisto-chemistry. Fibroblasts isolated from fresh skin tissue were used to detect the expression of PRSS23 by real-time quantitative PCR (RT-qPCR) and Western blot. Overexprssion of PRSS23 in BJ, the fibroblasts cell line of skin, was constructed by lentivirus. After stimulation with 400 μmol/L hydrogen peroxide for 12 h, Annexin V/7-AAD staining was used to detect apoptosis of fibroblasts; flow cytometry and Western blot were used to detect the expression of apoptosis-related protein cleaved Caspase-3. The expression of interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) in fibroblasts was detected by RT-qPCR and enzyme linked immunosorbent assay (ELISA). RESULTS: Compared with the healthy controls, the expression of PRSS23 in skin tissues of the SSc patients was significantly increased [4.952 (3.806-5.439) vs. 0.806 (0.395-1.173), P < 0.001], and fibroblast was the main cell that expressed PRSS23. The mRNA [27.59 (25.02-30.00) vs. 1.00, P < 0.001] and protein [0.675 (0.587-0.837) vs. 0.451 (0.342-0.502), P=0.029] of PRSS23 in skin fibroblasts isolated from the SSc patients were significantly up-regulated. Compared with the control group, the anti-apoptotic ability of skin fibroblasts overexpressing PRSS23 was enhanced, and the proportion of apoptotic cells was significantly reduced after hydrogen peroxide induction [(5.043±1.097)% vs. (17.480±3.212)%, P=0.022], the expression of apoptosis-related protein cleaved Caspase-3 was also markedly reduced [(0.718±0.022) vs. (1.422±0.105), P=0.003]. In addition, the mRNA [(99.780±1.796) vs. (1.000±0.004), P < 0.001] and protein [(211.600±2.431) ng/L vs. (65.930±1.768) ng/L, P < 0.001] of IL-6 in the fibroblasts overexpressing PRSS23 were significantly up-regulated; the mRNA[(3.555±0.555) vs. (1.000±0.004), P < 0.001] and protein levels [(41.190±0.949) ng/L vs. (31.150±0.360) ng/L, P < 0.001] of TNF-α in the fibroblasts overexpressing PRSS23 were also significantly up-regulated. CONCLUSION The expression of PRSS23 is increased in skin fibroblasts of SSc patients. PRSS23 can inhibit cell apoptosis, promote the secretion of inflammatory factors such as IL-6 and TNF-α, and regulate the process that skin fibroblasts transform into pro-inflammatory type. So, PRSS23 is associated with the development of skin fibrosis.
Humans ; Scleroderma, Systemic/enzymology* ; Fibroblasts/pathology* ; Apoptosis ; Skin/metabolism* ; Fibrosis ; Interleukin-6/metabolism* ; Caspase 3/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Male ; Female ; Cells, Cultured ; RNA, Messenger/metabolism* ; Middle Aged ; Adult ; Serine Endopeptidases/genetics*

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

OBJECTIVE: To determine the role of Tripterygium wilfordii multiglycoside (TGW) in the treatment of psoriatic dermatitis from a cellular immunological perspective. METHODS: Mouse models of psoriatic dermatitis were established by imiquimod (IMQ). Twelve male BALB/c mice were assigned to IMQ or IMQ₊TGW groups according to a random number table. Histopathological changes in vivo were assessed by hematoxylin and eosin staining. Ratios of immune cells and cytokines in mice, as well as PAM212 cell proliferation in vitro were assessed by flow cytometry. Pro-inflammatory cytokine expression was determined using reverse transcription quantitative polymerase chain reaction. RESULTS: TGW significantly ameliorated the severity of IMQ-induced psoriasis-like mouse skin lesions and restrained the activation of CD45⁺ cells, neutrophils and T lymphocytes (all P<0.01). Moreover, TGW significantly attenuated keratinocytes (KCs) proliferation and downregulated the mRNA levels of inflammatory cytokines including interleukin (IL)-17A, IL-23, tumor necrosis factor α, and chemokine (C-X-C motif) ligand 1 (P<0.01 or P<0.05). Furthermore, it reduced the number of γ δ T17 cells in skin lesion of mice and draining lymph nodes (P<0.01). CONCLUSIONS TGW improved psoriasis-like inflammation by inhibiting KCs proliferation, as well as the associated immune cells and cytokine expression. It inhibited IL-17 secretion from γ δ T cells, which improved the immune-inflammatory microenvironment of psoriasis.
Male ; Animals ; Mice ; Tripterygium ; Psoriasis/drug therapy* ; Keratinocytes ; Skin Diseases/metabolism* ; Cytokines/metabolism* ; Imiquimod/metabolism* ; Dermatitis/pathology* ; Disease Models, Animal ; Mice, Inbred BALB C ; Skin/metabolism*

OBJECTIVES: Ozone is widely applied to treat allergic skin diseases such as eczema, atopic dermatitis, and contact dermatitis. However, the specific mechanism remains unclear. This study aims to investigate the effects of ozonated oil on treating 2,4-dinitrochlorobenzene (DNCB)-induced allergic contact dermatitis (ACD) and the underling mechanisms. METHODS: Besides the blank control (Ctrl) group, all other mice were treated with DNCB to establish an ACD-like mouse model and were randomized into following groups: a model group, a basal oil group, an ozonated oil group, a FcεRI-overexpressed plasmid (FcεRI-OE) group, and a FcεRI empty plasmid (FcεRI-NC) group. The basal oil group and the ozonated oil group were treated with basal oil and ozonated oil, respectively. The FcεRI-OE group and the FcεRI-NC group were intradermally injected 25 µg FcεRI overexpression plasmid and 25 µg FcεRI empty plasmid when treating with ozonated oil, respectively. We recorded skin lesions daily and used reflectance confocal microscope (RCM) to evaluate thickness and inflammatory changes of skin lesions. Hematoxylin-eosin (HE) staining, real-time PCR, RNA-sequencing (RNA-seq), and immunohistochemistry were performed to detct and analyze the skin lesions. RESULTS: Ozonated oil significantly alleviated DNCB-induced ACD-like dermatitis and reduced the expressions of IFN-γ, IL-17A, IL-1β, TNF-α, and other related inflammatory factors (all P<0.05). RNA-seq analysis revealed that ozonated oil significantly inhibited the activation of the DNCB-induced FcεRI/Syk signaling pathway, confirmed by real-time PCR and immunohistochemistry (all P<0.05). Compared with the ozonated oil group and the FcεRI-NC group, the mRNA expression levels of IFN-γ, IL-17A, IL-1β, IL-6, TNF-α, and other inflammatory genes in the FcεRI-OE group were significantly increased (all P<0.05), and the mRNA and protein expression levels of FcεRI and Syk were significantly elevated in the FcεRI-OE group as well (all P<0.05). CONCLUSIONS Ozonated oil significantly improves ACD-like dermatitis and alleviated DNCB-induced ACD-like dermatitis via inhibiting the FcεRI/Syk signaling pathway.
Animals ; Mice ; Dinitrochlorobenzene/metabolism* ; Skin/metabolism* ; Cytokines/metabolism* ; Interleukin-17/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Dermatitis, Allergic Contact/pathology* ; Dermatitis, Atopic/chemically induced* ; Signal Transduction ; RNA, Messenger/metabolism* ; Mice, Inbred BALB C

Keloids are a common type of pathological scar as a result of skin healing, which are extremely difficult to prevent and treat without recurrence. The pathological mechanism of keloids is the excessive proliferation of fibroblasts, which synthesize more extracellular matrices (ECMs), including type I/III collagen (COL-1/3), mucopolysaccharides, connective tissue growth factor (CTGF, also known as cellular communication network factor 2 (CCN2)), and fibronectin (FN) in scar tissue, mostly through the abnormal activation of transforming growth factor-‍β (TGF-‍β)/Smads pathway (Finnson et al., 2013; Song et al., 2018). Genetic factors, including race and skin tone, are considered to contribute to keloid formation. The reported incidence of keloids in black people is as high as 16%, whereas white people are less affected. The prevalence ratio of colored people to white people is 5:1‍‍-‍‍15:1 (Rockwell et al., 1989; LaRanger et al., 2019). In addition, keloids have not been reported in albinism patients of any race, and those with darker skin in the same race are more likely to develop this disease (LaRanger et al., 2019). Skin melanocyte activity is significantly different among people with different skin tones. The more active the melanocyte function, the more melanin is produced and the darker the skin. Similarly, in the same individual, the incidence of keloids increases during periods when melanocytes are active, such as adolescence and pregnancy. Keloids rarely appear in areas where melanocytes synthesize less melanin, such as in the palms and soles. Thus, the formation of keloids seems to be closely related to melanocyte activity.
Adolescent ; Cells, Cultured ; Exosomes/metabolism* ; Fibroblasts/metabolism* ; Humans ; Keloid/pathology* ; Melanins/metabolism* ; Melanocytes/pathology* ; Pilot Projects ; Skin/metabolism* ; Transforming Growth Factor beta/metabolism*

Hypertrophic scar is a pathological repair result of excessive accumulation of extracellular matrix after skin damage, which affects the appearance and function of patients with varying degrees. The degree of scar formation is directly related to the strength of inflammatory reaction during wound healing, and excessive or prolonged inflammatory response increases the incidence of hypertrophic scars. Interleukin-6 (IL-6) is a pleiotropic cytokine that is involved in regulating the fibrotic network composed of fibroblasts, macrophages, keratinocytes, and vascular endothelial cells, and is closely related to the formation of hypertrophic scars. This article reviews the role of IL-6 and its signaling pathway in hypertrophic scar formation.
Cicatrix, Hypertrophic/pathology* ; Endothelial Cells/metabolism* ; Fibroblasts/metabolism* ; Humans ; Interleukin-6 ; Skin/pathology* ; Wound Healing/physiology*

Objective: To explore the effect of deep dermal tissue dislocation injury on skin fibrosis in pig, in order to provide some theoretical basis for burn scar treatment. Methods: The experimental research method was applied. Six 2-month-old female Duroc pigs were taken. Fifteen operative areas on the right dorsum of pigs on which medium-thick skin grafts and deep dermal tissue slices were cut and re-implanted were included into dermal in situ reimplantation group, and fifteen operative areas on the left dorsum of pigs on which medium-thick skin grafts and deep dermal tissue slices were cut and the deep dermal tissue slice was placed under the fat layer were included into the dermal dislocation group. The hair growth in the operative areas on post-injury day (PID) 7, 14, and 21 and the cross-sectional structure on PID 14 were observed in the two groups. On PID 7, 14, and 21, the skin thickness (the distance from the epidermis to the upper edge of the fat), the dermal thickness (the distance from the lower edge of the epidermis to the upper edge of the fat, excluding the fibrotic tissue thickness between the dermis and the fat), and the fibrosis tissue thickness of the dermis-fat interface (from the lower edge of the deep dermis to the upper edge of the fat in dermal in situ reimplantation group and from the lower edge of the superficial dermis to the upper edge of the fat in dermal dislocation group) in the operative areas were measured and compared between the two groups; the fibrotic tissue thickness at the dermal cutting interface (from the lower edge of the superficial dermis to the upper edge of the deep dermis) in the operative areas in dermal in situ reimplantation group was measured and compared with the fibrotic tissue thickness at the dermal-fat interface. Sirius red staining was performed to observe and compare the type Ⅰ and Ⅲ collagen content in the dermal-fat interface in the operative areas between the 2 groups and between the dermal cutting interface and dermal-fat interface in the operative areas in dermal in situ reimplantation group. Immunohistochemical staining was performed to observe the positive expressions of proliferating cell nuclear antigen (PCNA), transforming growth factor β₁ (TGF-β₁), fibroblast growth factor 2 (FGF-2), and hepatocyte growth factor (HGF) in the operative areas in the two groups. The sample number was 6. Data were statistically analyzed with independent sample t test. Results: On PID 7, 14, and 21, the hairs in the operative areas in dermal in situ reimplantation group were denser than those in dermal dislocation group. On PID 14, the skin cross section in the operative areas in dermal dislocation group showed a "sandwich"-like structure, while the skin cross section in the operative areas in dermal in situ reimplantation group had normal structure. On PID 7, 14, and 21, the skin thickness in the operative areas in dermal dislocation group was (4 234±186), (4 688±360), and (4 548±360) μm, respectively, which was close to (4 425±156), (4 714±141), and (4 310±473) μm in dermal in situ reimplantation group (P>0.05); the dermal thickness in the operative areas in dermal dislocation group was significantly thinner than that in dermal in situ reimplantation group (with t values of -9.73, -15.85, and -15.41, respectively, P<0.01); the fibrotic tissue thickness at the dermal-fat interface in the operative areas in dermal dislocation group was significantly thicker than that in dermal in situ reimplantation group (with t values of 14.48, 20.58, and 15.67, respectively, P<0.01); there was no statistically significant difference between the fibrotic tissue thickness at the dermal-fat interface and the dermal cutting interface in the operative areas in dermal in situ reimplantation group (P>0.05). On PID 7, 14, 21, the type Ⅲ collagen content in the dermal-fat interface in the operative areas in dermal dislocation group was increased significantly compared with that in dermal in situ replantation group (with t values of 2.65, 0.61, and 7.39, respectively, P<0.05 or P<0.01), whereas there were no statistically significant differences in the type Ⅰ collagen content at the dermal-fat interface in the operative areas between the 2 groups (P>0.05) and the type Ⅰ and Ⅲ collagen content between the dermal-fat interface and the dermal cutting interface in the operative areas in dermal in situ reimplantation group (P>0.05). On PID 7, 14, and 21, PCNA, TGF-β₁, FGF-2, and HGF were positively expressed in the superficial dermis and adipose tissue in the operative areas in dermal dislocation group, while PCNA, TGF-β₁, FGF-2, and HGF were positively expressed in the superficial dermis, deep dermis, and adipose tissue in the operative areas in dermal in situ reimplantation group. Conclusions: Inadequate intrinsic thickness of dermal tissue is the key factor causing fibrosis, and the biological purpose of fibrosis is to "compensate" the intrinsic thickness of the skin. Besides, adipose tissue may also be an important component of fibrotic skin repair.
Swine ; Female ; Animals ; Dermis/pathology* ; Proliferating Cell Nuclear Antigen/metabolism* ; Fibroblast Growth Factor 2 ; Cross-Sectional Studies ; Fibrosis ; Skin Diseases/pathology* ; Collagen/metabolism*