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*

OBJECTIVE: To investigate the expression and physiological significance of the ferroptosis marker 4-hydroxynonenal (4-HNE) in myofibroblasts induced by transforming growth factor-β1 (TGF-β1), providing theoretical evidence for its potential role in the diagnosis and treatment of fibrosis in systemic sclerosis (SSc). METHODS: Mouse embryonic fibroblasts (NIH3t3) were cultured and divided into two groups after 12 h of starvation: the control group (cultured in 1% serum-containing medium) and the TGF-β1 group (cultured in 10 μg/L TGF-β1 with 1% serum-containing medium). Cell morphology changes in both groups were observed under a microscope. To confirm successful establishment of the SSc cell model, fibrosis markers were analyzed using reverse transcription quantitative real-time PCR (RT-qPCR) and Western blot. Next, flow cytometry was employed to assess the intracellular levels of reactive oxygen species (ROS) in both groups. Finally, Western blot and immunofluorescence staining were used to measure the expression of 4-HNE in the TGF-β1-treated cells. RESULTS: Microscopic observations revealed that TGF-β1 treatment caused the NIH3t3 cells to transition from a typical spindle shape to a flat, polygonal shape with multiple protrusions, indicating fibroblast activation. The RT-qPCR and Western blot analyses showed that the expression of the fibrosis marker Vimentin was significantly upregulated in the TGF-β1 group compared with the control group (P < 0.01), confirming that TGF-β1 effectively promoted fibrosis-related gene and protein expression. Flow cytometry results indicated that TGF-β1 significantly elevated intracellular ROS levels, suggesting the induction of oxidative stress. Furthermore, both Western blot and immuno-fluorescence staining demonstrated a significant increase in 4-HNE expression in the TGF-β1-treated cells (immunofluorescence intensity P < 0.05). CONCLUSION TGF-β1 promotes fibroblast activation and fibrosis while inducing ROS production, leading to a marked increase in 4-HNE expression. Given the role of 4-HNE as a marker of lipid peroxidation and its elevated levels in the SSc cell model, this study suggests that 4-HNE could serve as a potential biomarker for fibrosis in SSc. The findings highlight the importance of investigating the mechanisms of 4-HNE in fibrosis and suggest that targeting this pathway could offer new therapeutic opportunities for treating SSc.
Animals ; Mice ; Scleroderma, Systemic/pathology* ; Aldehydes/pharmacology* ; Transforming Growth Factor beta1/metabolism* ; NIH 3T3 Cells ; Ferroptosis ; Reactive Oxygen Species/metabolism* ; Fibrosis ; Fibroblasts/metabolism* ; Biomarkers/metabolism* ; Myofibroblasts/metabolism*

OBJECTIVE: To study the preventive and therapeutic effects of safflower water extract on systemic scleroderma (SSc) in mice and its mechanism. METHODS: Sixty BALB/C mice were randomly divided into the control group, model group, prednisone group and safflower low, middle, high dose groups, 10 mice in each group.The control group was injected with normal saline, and the other five groups were subcutaneously injected with bleomycin hydrochloride with 100 μl at the concentration of 200 μg /ml on the back, once a day for 28 days to establish the SSc models.At the same time, the control group and model group were treated with normal saline (10 ml/kg), the prednisone group was treated with prednisone 4.5 mg/kg (10 ml/kg), and the low, middle, and high dose safflower groups were treated with safflower at the doses of 1.5, 3, 6 g/kg (10 ml/kg), and all groups were treated for 28 days.After 28 days, all mice were decapitated. The blood samples and back skin of the BLM injection part were collected.After that, all the tissue slices were taken to measure the dermal thickness, and the content of hydroxyproline (HYP) in the skin tissues was detected by hydrolysis method.The contents of tissue growth factor (CTGF) and transforming growth factor-β (TGF-β ) in the skin tissues and the levels of interleukin-6 (IL-6) and interleukin-17 (IL-17) in serum were determined by ELISA. RESULTS: Compared with the control group, the dermal thickness of the model group was increased(P＜0.05), the contents of CTGF, TGF-β and HYP in the skin tissues and the levels of IL-6 and IL-17 in the serum of the model group were increased(P＜0.05); compared with the model group, the dermal thickness in the prednisone group and safflower groups was decreased (P＜0.05), the levels of CTGF, TGF-β and HYP in the skin tissues and the serum levels of IL-6 and IL-17 in the prednisone group and safflower groups were decreased (P＜0.05). CONCLUSION Safflower water extract can improve skin condition (or dermal thickness) in SSc mice, and its mechanism may be related to reducing immune inflammatory response.
Animals ; Bleomycin ; Carthamus tinctorius ; chemistry ; Connective Tissue Growth Factor ; metabolism ; Disease Models, Animal ; Hydroxyproline ; analysis ; Interleukin-17 ; metabolism ; Interleukin-6 ; metabolism ; Mice ; Mice, Inbred BALB C ; Plant Extracts ; pharmacology ; Random Allocation ; Scleroderma, Systemic ; drug therapy ; Skin ; pathology ; Transforming Growth Factor beta1 ; metabolism

Uncontrolled fibrosis of skin and internal organs is the main characteristic of scleroderma, and collagen is a major extracellular matrix protein that deposits in the fibrotic organs. As the chaperone of collagen, heat shock protein 47 (HSP47) is closely related with the development of fibrosis. To explore the potential function of HSP47 in the pathogenesis of scleroderma, the clinical, in vivo and in vitro studies were performed. In clinical, the increased mRNA level of HSP47 was observed in the skin fibroblasts and PBMC from scleroderma patients, and the enhanced protein level of HSP47 was also detected in the skin biopsy and plasma of the above patients. Unexpectedly, the enhanced levels of HSP47 were positively correlated with the presence of anti-centromere antibody in scleroderma patients. Moreover, a high expression of HSP47 was found in the skin lesion of BLM-induced scleroderma mouse model. Further in vitro studies demonstrated that HSP47 knockdown could block the intracellular and extracellular collagen over-productions induced by exogenous TGF-β. Therefore, the results in this study provide direct evidence that HSP47 is involved in the pathogenesis of scleroderma. The high expression of HSP47 can be detected in the circulatory system of scleroderma patients, indicating that HSP47 may become a pathological marker to assess the progression of scleroderma, and also explain the systemic fibrosis of scleroderma. Meanwhile, collagen over-expression is blocked by HSP47 knockdown, suggesting the possibility that HSP47 can be a potential therapeutic target for scleroderma.
Adolescent ; Adult ; Animals ; Biopsy ; Blotting, Western ; Cells, Cultured ; Collagen ; metabolism ; Female ; Fibroblasts ; drug effects ; metabolism ; Fibrosis ; HSP47 Heat-Shock Proteins ; blood ; genetics ; metabolism ; Humans ; Leukocytes, Mononuclear ; metabolism ; Male ; Mice ; Mice, Inbred C3H ; Middle Aged ; NIH 3T3 Cells ; Protein Binding ; RNA Interference ; Reverse Transcriptase Polymerase Chain Reaction ; Scleroderma, Systemic ; blood ; genetics ; metabolism ; Skin ; metabolism ; pathology ; Transforming Growth Factor beta ; pharmacology ; Young Adult

OBJECTIVETo study the role of platelet-derived growth factor A (PDGF-A)/PDGF receptor-α (PDGFR-α) signaling pathway in the proliferation and transdifferentiation of fibroblasts (FB) into myofibroblasts (MFB) in the skin lesions of patients with systemic sclerosis (SSc).

METHODSThe primary FBs isolated from the skin lesions of SSc patients and normal adult skin cultured in vitro were examined for α-smooth muscle actin (α-SMA) using immunocytochemistry. The FBs were incubated with different concentrations of PDGF-AA and the changes in their proliferative activity were quantified with MTT assay. RT-PCR was used to determine the effects of transforming growth factor-β(1) (TGF-β(1)) and PDGF-AA, either alone or in combination, on the expression levels of PDGFR-α and α-SMA mRNA in the FBs.

RESULTSAlthough the FBs of the two groups were morphologically similar, only FBs from the skin lesion showed positive staining for α-SMA. Below the saturated concentration of PDGF, the FBs in the two groups both proliferated in a dose-dependent manner (P<0.05), but the FBs from the SSc lesions always showed a significantly higher proliferative activity (P<0.05). PDGF-AA and TGF-β(1), alone or in combination, up-regulated the expression level of PDGFR-α and α-SMA mRNA in the FBs from SSc lesions; similar results were obtained in the control FBs, except that TGF-β(1) alone did not influence PDGFR-α mRNA expression. PDGFR-α and α-SMA mRNA always showed higher expressions in FBs in SSc lesions than in the control FBs with the same treatments (P<0.05). The expression levels of PDGFR-α and α-SMA mRNA increased in the order of untreated, PDGF-AA, TGF-β(1) and PDGF-AA plus TGF-β(1) groups and showed a strong positive correlation between them (r=0.925, P<0.05).

CONCLUSIONThe FBs from the skin lesions of SSc patients have a distinct feature of transdifferentiation into MFB. Over-expression of PDGFR-α on the surface of FBs from SSc lesions can bind more PDGF-AA ligands to increase cell proliferation and promote transdifferentiation to MFB, and TGF-β(1) further enhances this effect .

Actins ; metabolism ; Adult ; Cell Proliferation ; Cell Transdifferentiation ; Cells, Cultured ; Female ; Fibroblasts ; cytology ; Humans ; Male ; Middle Aged ; Myofibroblasts ; cytology ; Platelet-Derived Growth Factor ; metabolism ; Receptor, Platelet-Derived Growth Factor alpha ; metabolism ; Scleroderma, Systemic ; metabolism ; pathology ; Signal Transduction ; Transforming Growth Factor beta ; pharmacology

The elastin metabolism in systemic sclerosis (SSc) has been known to be abnormal. The authors investigated relationship between the clinical manifestations of systemic sclerosis (SSc) and serum levels of soluble elastin-derived peptide (S-EDP) and anti-elastin antibodies. Serum samples were obtained from 79 patients with SSc and 79 age- and sex-matched healthy controls. Concentrations of serum S-EDP and anti-elastin antibodies were measured by ELISA. The serum concentrations of S-EDP in SSc patients were significantly higher than in healthy controls (median, 144.44 ng/mL vs 79.59 ng/mL, P < 0.001). Serum EDP concentrations were found to be correlated with disease duration in SSc (P = 0.002) and particularly in diffuse cutaneous SSc (P = 0.005). Levels of anti-elastin antibodies were found to be more elevated in SSc patients than in healthy controls (median, 0.222 U vs 0.191 U, P = 0.049), more increased in diffuse cutaneous SSc than limited cutaneous SSc (median, 0.368 U vs 0.204 U, P = 0.031). In addition, levels of anti-elastin antibodies were also found to be negatively associated with presence of anti-centromere antibody (P = 0.023). The S-EDP levels were not found to be correlated with levels of anti-elastin antibodies. The increased S-EDP and anti-elastin antibody levels and association with clinical and laboratory characteristics may reflect the abnormal metabolism in SSc.
Adult ; Antibodies, Anti-Idiotypic/*blood/immunology ; Centromere/immunology ; Elastin/*blood/immunology ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Male ; Middle Aged ; Peptides/*blood/immunology ; Scleroderma, Systemic/*metabolism/pathology

OBJECTIVETo study the role of abnormally activated Wnt/β-catenin signal pathway in the pathogenesis of scleroderma (SD) and its association with the clinical classification of SD.

METHODSThe expression and distribution of Wnt 2, Wnt 3a, and β-catenin in the skin lesions of 45 SD patients, including 25 with systemic sclerosis (SSc) and 20 with localized scleroderma (LSc), were detected with SP immunohistochemistry, using 20 samples from healthy skin tissues as normal control.

RESULTSIn the dermis and epidermis of the SD skin lesions, Wnt 2 and Wnt 3a were located in the cytoplasm and cell nuclei, respectively; β-catenin was distributed in the nuclei of dermal fibroblast-like cells, glandular epithelium cells and infiltrating lymphocytes, and on the cell membrane in normal and a part of the affected epidermis. The skin lesions of SD patients showed obviously increased staining intensity of cytoplasmic Wnt 2, nuclear Wnt 3a and β-catenin, but markedly lowered cell membrane staining of β-catenin than normal skins (P<0.01). Both Wnt 2 and Wnt 3a were positively correlated with nuclear β-catenin deposition (r=0.663 and 0.654, P<0.01) and negatively with cell membrane β-catenin staining (r=-0.532 and -0.529, P<0.01). No significant difference was found in the staining intensities of the 3 proteins between SSc and LSc (P>0.05).

CONCLUSIONAbnormal activation of Wnt/β-catenin pathway occurs in the skin lesions of SD patients, which may play an important role in the pathogenesis of SD. SSc and LSc represent the two opposite ends of the SD spectrum rather than two separate diseases.

Adolescent ; Adult ; Case-Control Studies ; Female ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Scleroderma, Systemic ; metabolism ; pathology ; Signal Transduction ; Skin ; pathology ; Wnt Signaling Pathway ; Wnt2 Protein ; metabolism ; Wnt3A Protein ; metabolism ; Young Adult ; beta Catenin ; metabolism

Actins ; metabolism ; Adult ; Amyloidosis ; pathology ; Diagnosis, Differential ; Female ; Humans ; Intestinal Pseudo-Obstruction ; metabolism ; pathology ; Lupus Erythematosus, Systemic ; pathology ; Muscular Atrophy ; pathology ; Scleroderma, Systemic ; pathology ; Young Adult

OBJECTIVETo explore the role of the fibroblast transdifferentiation into myofibroblasts (MFBs) in the pathogenesis of systemic sclerosis (SSc) and investigate the influence of transforming growth factor β(1) (TGF-β(1)) and blocking of its signal transduction on fibroblast transdifferentiation.

METHODSFibroblasts derived from the skin lesions of SSc patients and normal skin tissue were cultured in vitro. The proportion of MFBs in the fibroblast culture was analyzed qualitatively using immunocytochemistry and quantitatively with ELISA for α-smooth muscle actin (α-SMA). The changes in fibroblast transdifferentiation were observed after addition of TGF-β(1) in the cell culture and after blocking the signal transduction of TGF-β(1).

RESULTSThe fibroblasts isolated from SSc patients and control subjects showed a similar morphology. The mean number of cells positive for α-SMA in SSc group was significantly higher than that in the control group (P<0.01). As culture time extended, α-SMA levels of the two groups both increased gradually (P<0.01), but the increments were significantly greater in SSc group than in the control group at 24, 48, and 72 h (P<0.05 all). Addition of TGF-β(1) resulted in significantly increased α-SMA levels in both groups (P<0.05), and SSc group showed significantly higher α-SMA levels than the control group at 24, 48, and 72 h (P<0.01). In the presence of TGF-β(1), blocking of Smads, ERK/MAPK, and p38MAPK pathways, but not JNK/MAPK pathway, caused an obvious decrease in α-SMA levels in the fibroblasts in both groups.

CONCLUSIONThe fibroblasts in the skin lesion of SSc patients have strong potential of transdifferentiation into MFBs, and TGF-β(1) can promote this transdifferentiation process possibly involving Smads, and ERK/MAPK, and p38MAPK signalling pathways.

Actins ; metabolism ; Adult ; Cell Transdifferentiation ; physiology ; Cells, Cultured ; Female ; Fibroblasts ; pathology ; Humans ; Male ; Myofibroblasts ; pathology ; Scleroderma, Systemic ; pathology ; Signal Transduction ; Skin ; pathology ; Transforming Growth Factor beta1 ; metabolism

The hallmark of scleroderma is fibrosis by excessive extracellular matrix (ECM) deposition in the skin, lung, and other organs. Increasing evidence suggests that overexpression of transforming growth factor-beta (TGF-beta) and its receptors play a key pathogenic role in the development of tissue fibrosis in scleroderma. TGF-beta is known to induce the expression of ECM proteins in the pathogenesis of fibrosis in systemic sclerosis. Investigations into TGF-beta pathways will suggest new treatment strategies for fibrotic diseases.
Animals ; Extracellular Matrix ; metabolism ; pathology ; Extracellular Matrix Proteins ; metabolism ; Fibroblasts ; metabolism ; Fibrosis ; Humans ; Receptors, Transforming Growth Factor beta ; metabolism ; Scleroderma, Systemic ; etiology ; metabolism ; Transforming Growth Factor beta ; metabolism