Smad Signaling Research Articles

TGF-β induces cholesterol accumulation to regulate the secretion of tumor-derived extracellular vesicles

BackgroundCancer cells are avid extracellular vesicle (EV) producers. EVs transport transforming growth factor-β (TGF-β), which is commonly activated under late stages of cancer progression. Nevertheless, whether TGF-β signaling coordinates EV biogenesis is a relevant topic that remains minimally explored.MethodWe sought after specific TGF-β pathway mediators that could regulate EV release. To this end, we used a large number of cancer cell models, coupled to EV cell biological assays, unbiased proteomic and transcriptomic screens, followed by signaling and cancer biology analyses, including drug resistance assays.ResultsWe report that TGF-β, by activating its type I receptor and MEK-ERK1/2 signaling, increased the numbers of EVs released by human cancer cells. Upon examining cholesterol as a mediator of EV biogenesis, we delineated a pathway whereby ERK1/2 acted by phosphorylating sterol regulatory element-binding protein-2 that transcriptionally induced 7-dehydrocholesterol reductase expression, thus raising cholesterol abundance at both cellular and EV levels. Notably, inhibition of MEK or cholesterol synthesis, which impaired TGF-β-induced EV secretion, sensitized cancer cells to chemotherapeutic drugs. Furthermore, proteomic profiling of two distinct EV populations revealed that EVs secreted by TGF-β-stimulated cells were either depleted or enriched for different sets of cargo proteins. Among these, latent-TGF-β1 present in the EVs was not affected by TGF-β signaling, while TGF-β pathway-related molecules (e.g., matrix metalloproteinases, including MMP9) were either uniquely enriched on EVs or strongly enhanced after TGF-β stimulation. EV-associated latent-TGF-β1 activated SMAD signaling, even when EV uptake was blocked by heparin, indicating competent signaling capacity from target cell surface receptors. MMP inhibitor or proteinase treatment blocked EV-mediated SMAD signaling, suggesting that EVs require MMP activity to release the active TGF-β from its latent complex, a function also linked to the EV-mediated transfer of pro-migratory potential and ability of cancer cells to survive in the presence of cytotoxic drugs.ConclusionHence, we delineated a novel signaling cascade that leads to high rates of EV generation by cancer cells in response to TGF-β, with cholesterol being a key intermediate step in this mechanism.Graphical • TGF-β increases EV release by activating a MEK-ERK1/2-SREBP2-DHCR7 signaling and transcriptional pathway.• TGF-β-induced DHCR7 expression raises cholesterol abundance that promotes EV release.• EVs carry surface latent TGF-β and MMP9 that can activate TGF-β receptor signaling on the surface of recipient cells.

Perfluorooctanoic acid induced lung toxicity via TGF-β1/Smad pathway, crosstalk between airway hyperresponsiveness and fibrosis: withdrawal impact.

Perfluorooctanoic acid (PFOA) is an environmental persistent agent to which humans are exposed daily through food and water. This study investigated the lung toxic effects induced by ingested PFOA (30 mg/kg/day) for 8 weeks in adult male rats and the impact following 8 weeks of its withdrawal. PFOA increased MDA and reduced TAC inducing oxidative stress. It induced airway hyperresponsiveness (AHR) via increased bronchoalveolar lavage fluid (BALF) IL-4, IL-5, IL-13, IL-9, eosinophil count, TNF-α, and IL-1ß; reduced IL-12; increased serum IgE; and increased urocortin expression in lung tissues. Moreover, it induced pulmonary fibrosis via increased serum KL-6, and SFTP-D, altered pulmonary structure, and increased deposition of collagen fibers in lung tissues. Furthermore, it increased TGF-β1, Smad2, and Smad3 and reduced Smad7 gene expression in lung tissues. These gene alterations were positively correlated with AHR and fibrosis-related factors. The recovered lung upon PFOA withdrawal showed complete resolution of oxidative stress and slight amelioration of other studying parameters. Exposure to PFOA induced lung toxicity by disrupting the TGF-β1/Smad signaling pathway, which acts as a crosstalk between AHR and fibrosis. Additionally, PFOA altered pulmonary architecture, triggered inflammation, and caused oxidative stress. The lung exhibited partial alleviation upon recovery.

The molecule events expression of TGF-β/Smad signaling pathway in morphological and structural developmental characteristics of gonads in goose embryos.

China is the largest producer and consumer of geese with significant social and economic value in agriculture. The Jilin White Goose, known for its excellent egg-laying and reproductive characteristics, is a prominent breeding breed in the northeast of China widely used for cross-breeding.Gonad development is a complex process, which will differentiate into testes or ovaries, thus affecting sex determination. Since the level of gonadal development in geese of different sexes is also related to their productivity, the study of gonadal function in geese is of great theoretical and practical importance. In this study, we used the embryonic gonads of Jilin white geese as the research object to reveal the morphologic and histologic developmental characteristics and process of the gonads of goose embryos from the 9th day to the 28th day and to investigate the mechanisms regulating the differentiation of the gonads. The results of ALP-PAS staining by histomorphological observations showed that the primordial germ cells in the female gonads were fully differentiated at embryonic day 19 (E19) and in the male gonads at embryonic day 18 (E18).Previous studies indicate that the TGF-β /Smad signaling pathway is crucial for sex differentiation and gamete formation in animals. In our study, we quantitatively analyzed key genes and proteins in this pathway within goose embryos. We found that TGF-βRI/II receptors and Smad2/3 are involved in gonadal development early in differentiation. Smad2 protein levels peaked at E18 in male gonads and E19 in female gonads, while Smad3 peaked at E10 for both. It has been suggested that there is a novel interaction between TGF-β and Wnt/β-catenin signaling pathway. In this study, the expression of LEF1, a protein downstream of the Wnt/β-catenin signaling pathway, peaked at E19 in the female gonads and at E18 in the male gonads, and the protein expression level of β-catenin was significantly increased in the female gonads at E19 and E28 and peaked at E28 in the male gonads. β-catenin expression levels were significantly higher in the male gonads than in the other periods and reached a minimum at E28. We injected the TMAO drug, which activates the TGF-β /Smad pathway, into goose embryos using the embryo injection technique to study how it affects gene and protein expression in this signaling pathway. We found that in female gonads, the levels of Smad2/3 proteins were lower than in the control group at E18, but higher than the control group at E19. In male gonads, the results for Smad3 proteins matched those of the females, while the results for Smad2 proteins were the opposite. This shows that TMAO activation of the TGF-β /Smad signaling pathway may impact gonadal development in goose embryos. In conclusion, this study suggest that the TGF-β /Smad and Wnt signaling pathways may enhance gonadal tissue development in goose embryos. The study identified key time points in gonadogenesis, providing a new theoretical basis for further research on the molecular mechanisms of gonadal development.

Ganoderic acid a potential protective impact on bleomycin (BLM) -induced lung fibrosis in albino mice: Targeting caveolin 1/TGF-β/ Smad and P38MAPK signaling pathway.

Bleomycin (BLM), an anticancer medication, can exacerbate pulmonary fibrosis by inducing oxidative stress and inflammation. Anti-inflammatory, anti-fibrotic, and antioxidant properties are exhibited by ganoderic acid A (GAA). So, we aim to assess GAA's protective impact on lung fibrosis induced via BLM. Forty mice were randomly classified into four groups. Lung fibrosis was induced by injection of BLM intraperitoneally (15mg/kg body weight). GAA was given by oral gavage (25mg/kg body weight). Lung tissue MDA, TAC, and GSH were assessed spectrophotometrically. As well, TGFβ, p38 MAPK, TNF-α, IL-1β, and CAV1 levels were measured by enzyme-linked immunosorbent assay. Gene expression of tumor growth factor beta (TGF-β), Smad2, Smad3, and glutamate-cysteine ligase (GCL) were also evaluated. GAA had significantly improved biochemical biomarkers as well as histopathology of the lung. The protective impact of GAA may be linked to the upregulation of GCL gene expression and subsequent GSH levels. In addition, the GAA-treated group showed a significant decrement in the levels of TGF-β, Smad2&3, P38 MAPK, TNF-α, IL1β, and MDA compared to BLM induced lung fibrosis group. GAA has a protective impact on lung fibrosis induced by BLM via downregulation of TGF-β and upregulation of CAV1 level and GCL expression which may play a critical role in the improvement of the pathogenesis of lung fibrosis induced via BLM.

Interferon regulatory factor 5 attenuates kidney fibrosis through transcriptional suppression of Tgfbr1.

Tubulointerstitial fibrosis is a common pathway of the progressive development of chronic kidney diseases (CKD) with different etiologies. The transcription factor interferon regulatory factor 5 (IRF5) can induce anti-type I interferons and proinflammatory cytokine genes and has been implicated as a therapeutic target for various inflammatory and autoimmune diseases. Currently, no experimental evidence has confirmed the role of IRF5 in CKD. Our results showed that IRF5 was aberrantly upregulated in fibrotic kidneys of CKD patients and was colocalized with tubular epithelial cells, peritubular endothelial cells and kidney interstitial fibroblasts. Up-regulation of IRF5 was also seen in unilateral ureteral obstruction (UUO), unilateral ischemia reperfusion and repeated low-dose cisplatin induced mice models, as well as TGF-β1-stimulated tubular epithelial cells and interstitial fibroblasts. Knockdown of Irf5 aggravated the degree of renal fibrosis in UUO mice. Consistently, overexpression of Irf5 attenuated TGF-β1-induced partial epithelial-to-mesenchymal transition and endothelial mesenchymal transition, as well as renal interstitial fibroblast activation and proliferation. Mechanistically, IRF5 can bind to the promoter region of Tgfbr1 and inhibit its transcription, thus inhibiting pro-fibrosis TGF-β1/Smad3 signal transduction. In summary, this research revealed an anti-fibrotic effect of exogenous IRF5 in tubular epithelial cells, endothelial cells and intestinal fibroblasts via transcriptionally repressing Tgfbr1. Activating IRF5 could therefore be a novel therapeutic strategy in the prevention of renal fibrosis.

Smad4 deficiency in hepatocytes attenuates NAFLD progression via inhibition of lipogenesis and macrophage polarization

Nonalcoholic fatty liver disease (NAFLD), a major cause of chronic liver disorders, has become a serious public health issue. Although the Smad4 signaling pathway has been implicated in the progression of NAFLD, the specific role of Smad4 in hepatocytes in NAFLD pathogenesis remains unclear. Hepatocyte-specific knockout Smad4 mice (AlbSmad4−/−) were first constructed using the Cre-Loxp recombinant system to establish a high-fat diet induced NAFLD model. The role of Smad4 in the occurrence and development of NAFLD was determined by monitoring the body weight of mice, detecting triglycerides and free fatty acids in serum and liver tissue homogenates, staining the tissue sections to observe the accumulation of liver fat, and RT-qPCR detecting the expression of genes related to lipogenesis, fatty acid intake, and fatty acid β oxidation. The molecular mechanism of Smad4 in hepatocytes affecting NAFLD was therefore investigated through combining in vitro and in vivo experiments. Smad4 deficiency in hepatocytes mitigated NAFLD progression and decreased inflammatory cell infiltration. Moreover, Smad4 deficiency inhibited CXCL1 secretion by suppressing the activation of the ASK1/P38/JNK signaling pathway. Furthermore, targeting CXCL1 using CXCR2 inhibitors diminished hepatocyte lipogenesis and inhibited the polarization of M1-type macrophages. Collectively, these results suggested that Smad4 plays a vital role in exacerbating NAFLD and may be a promising candidate for anti-NAFLD therapy.

Role of Xuefu Zhuyu decoction in improving pulmonary vascular remodeling by inhibiting endothelial-to-mesenchymal transition.

Pulmonary hypertension (pH) is a serious vascular disease characterized by pulmonary vascular remodeling. Xuefu Zhuyu decoction (XFZYD) can potentially improve the latter; however, its mechanism of action requires further investigation. Rat models of monocrotaline (MCT)-induced PH and chronic thromboembolic pulmonary hypertension (CTEPH) were employed to investigate whether XFZYD has the potential to improve pulmonary vascular remodeling. After 21 days of XFZYD administration, the right ventricular systolic pressure (RVSP), organ indices, and wall thickness of pulmonary arteries of the rats were measured. Considering the possibility of endothelial-to-mesenchymal transition (EndMT), the specific mechanism of XFZYD in improving pulmonary vascular remodeling was further explored. Immunofluorescence, immunohistochemistry, and western blotting were used to detect the expression of EndMT markers, transforming growth factor-β1 (TGF-β1)/Smad pathway-related proteins, hypoxia-inducible factor-1α (HIF-1α), and levels of reactive oxygen species (ROS) in the lung tissues. XFZYD demonstrated significant efficacy in treating PH, as evidenced by its effects in both the rat models of MCT-induced PH and CTEPH. XFZYD remarkably improved pulmonary vascular remodeling while reducing RVSP and right ventricular hypertrophy. XFZYD has the potential to improve pulmonary vascular remodeling by inhibiting EndMT in the pulmonary vasculature. The underlying mechanism may be closely associated with the inhibition of TGF-β1/Smad and HIF-1α signaling pathways and the reduction of ROS levels in lung tissue by XFZYD. This study indicates that XFZYD may inhibit EndMT by modulating the ROS/HIF-1α/TGF-β1 signaling pathway, thereby improving pulmonary vascular remodeling. These findings provide a theoretical foundation for the clinical application of XFZYD in PH.

Halofuginone prevents inflammation and proliferation of high-altitude pulmonary hypertension by inhibiting the TGF-β1/Smad signaling pathway

The inflammatory response of lung tissue and abnormal proliferation of pulmonary artery smooth muscle cells are involved in the pathogenesis of high-altitude pulmonary hypertension (HAPH). Halofuginone (HF), an active ingredient derivative of Chang Shan (Dichroa febrifuga Lour. [Hydrangeaceae]), has antiproliferative, antihypertrophic, antifibrotic, and other effects, but its protective effects on HAPH remains unclear. In the present study, we evaluated the efficacy of HF on HAPH by establishing a 6000 m HAPH rat model. Male Sprague–Dawley rats were divided into normoxia, normoxia + halofuginone (1 mg/kg), hypoxia, and hypoxia + halofuginone (1 mg/kg) groups. The results showed that HF (1 mg/kg) could prevent hypoxia-induced hemodynamic abnormalities, right ventricular hypertrophy, and pulmonary vascular remodeling in rats. We further detected the expression levels of inflammatory factors interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α) and proliferative/antiproliferative indicators proliferating cell nuclear antigen (PCNA), cyclin-dependent kinase 6 (CDK6), Cyclin D1, p21 in lung tissue, and found that HF could attenuate the lung tissue inflammatory response and proliferative response in HAPH rats. In addition, we also examined the expression levels of transforming growth factor-β1 (TGF-β1), Smad2/3 and p-Smad2/3 in lung tissue, and found that HF exerted therapeutic effects by inhibiting the TGF-β1/Smad signaling pathway.

Ambient PM25 Plus High‐Fat Diet Exacerbated Kidney Injury in Mice by Activating Ferroptosis Mediated TGF‐β1/Smad2 Signaling Pathway

ABSTRACTThe prevalence of chronic kidney disease (CKD) is on the rise globally, posing a significant public health concern. Numerous studies have indicated that the consumption of a high‐fat diet (HFD) can lead to renal injury, a condition closely linked to CKD. Additionally, research has shown that exposure to ambient PM2.5 is associated with an increased risk of CKD, suggesting that PM2.5 may serve as an environmental risk factor for CKD. However, the synergistic impact of PM2.5 and HFD on renal injury remains poorly understood. Therefore, the objective of our study was to investigate the combined effect of PM2.5 and HFD on renal injury. Male C57BL/6J mice were subjected to a 12‐week feeding regimen of either a normal diet or a HFD, while also being exposed to either saline or ambient PM2.5 through intratracheal instillation twice a week. Evaluation of renal function demonstrated that the HFD significantly elevated levels of serum blood urea nitrogen and serum creatinine. Furthermore, the combination of PM2.5 and HFD exhibited a synergistic effect, exacerbating the aforementioned indicators of kidney injury. Masson's trichrome staining revealed that both the HFD and/or PM2.5 induced renal fibrosis, with PM2.5 exacerbating the HFD‐induced renal fibrosis in the mice. In this study, Western blot analysis was conducted to examine the protein expressions of TGF‐β1 and p‐Smad2 in kidney tissues, which were found to be significantly increased in response to a HFD and/or exposure to PM2.5. Additionally, the impact of PM2.5 combined with HFD on renal ferroptosis was investigated. The results revealed that both HFD and PM2.5 led to an elevation in 4‐HNE concentration, a reduction in GSH content, a decrease in GPX4 protein expression, and an increase in ACSL4 protein expression in kidney tissues. Moreover, the combined exposure to PM2.5 and HFD exhibited a synergistic effect on GPX4 alterations in the kidney. Collectively, our findings suggest that the presence of PM2.5 exacerbates the renal injury, oxidative stress, and renal fibrosis induced by a HFD. This detrimental effect may be attributed to the activation of the ferroptosis‐mediated TGF‐β1/Smad2 signaling pathway.

Modulation of PRL-1 within placental MSCs instigates the transition between EMT and MET subsequent to hepatic fibrosis.

Epithelial-to-mesenchymal transition (EMT) plays a crucial role in hepatic fibrogenesis and liver repair in chronic liver disease. Our research highlights the antifibrotic potential of placenta-derived mesenchymal stem cells (PD-MSCs) and the role of phosphatase of regenerating liver-1 (PRL-1) in promoting liver regeneration. We evaluated the efficacy of PD-MSCs overexpressing PRL-1 (PD-MSCsPRL-1) in a bile duct ligation (BDL)-induced rat injury model, focusing on their ability to regulate EMT. PD-MSCsPRL-1 significantly reduced mesenchymal markers by downregulating TGFB1/SMAD2, outperforming naïve PD-MSCs. The transplantation of PD-MSCsPRL-1 enhanced BMP7/SMAD1/5 expression, promoting epithelial marker expression and stimulating BMP7 within hepatocytes, modulating downstream SMAD signaling. Importantly, further validation confirmed that PRL-1 directly interacts with BMP7 in hepatocytes. PRL-1 expression in PD-MSCsPRL-1 restores TGFB1/BMP7 balance, promoting hepatic regeneration through mesenchymal-to-epithelial transition (MET). These findings highlight the therapeutic potential of engineered MSCs for liver disease and suggest innovative strategies for future stem cell therapies.

1α,25(OH)2D3 Regulates the TGF-β1/Samd Signaling Pathway Inhibition of Hepatic Stellate Cell Activation.

To investigate the effect of 1α,25(OH)2D3 on hepatic stellate cells and the mechanism of the TGF-β1/Smad signaling pathway.LX2 cells were treated with TGF-β1 and different concentrations of 1α,25(OH)2D3. Cell proliferation was assessed using the CCK8 assay to determine the optimal concentration of 1α,25(OH)2D3 activity. The cell cycle and apoptotic rates were evaluated using flow cytometry. The expressions of Samd2, Samd3, Samd4, and Samd7 was assessed by western blotting, whereas the expression of MMP1, MMP13, and TIMP-1 was detected by qPCR.Compared with the control group, the 1α,25(OH)2D3 group had a higher apoptotic rate of LX2 cells, the cell cycle was blocked from the G1 stage to the S stage, the expressions of Samd2, Samd7, MMP1, and MMP13 increased, while the expressions of Samd3, Samd4, and TIMP-1 decreased.1α,25(OH)2D3 inhibits hepatic stellate cell activation and exerts anti-hepatic fibrosis effects by downregulating the expression of Samd3, Samd4, TIMP-1 and upregulating the expression of Samd2, Samd4, MMP1, and MMP13.

Aging-enhanced autophagy activity promotes fibrotic progression via the TGF-β2/Smad signaling pathway in trabecular meshwork cells-a new insight from POAG.

Glaucoma, a leading cause of irreversible blindness, is characterized by optic neuropathy and retinopathy, with primary open-angle glaucoma (POAG) being the most prevalent form. The primary pathogenic mechanism of POAG involves elevated intraocular pressure caused by chronic fibrosis of the trabecular meshwork (TM). Autophagy, a critical process for maintaining cellular homeostasis, has been implicated in fibrosis across various organs. However, its precise role in the fibrosis associated with POAG pathogenesis remains unclear. This study investigates the involvement of autophagy in TM fibrosis and explores its potential impact on POAG development, aiming to provide insights into new therapeutic targets. To assess autophagy activity and its relationship with fibrosis, we analyzed TM tissues from POAG patients and healthy donors. Autophagic activity in human TM tissues was measured through immunohistochemical analyses. An in vitro aging model using chronic H2O2 treatment was established to investigate the change of fibrosis in TM cells. Additionally, we used dexamethasone-treated TM cells as a POAG model to explore the role of autophagy in fibrotic progression. The involvement of the TGF-β2/Smad signaling pathway was investigated through western blot analysis and quantitative real-time PCR. This study reveals increased autophagic activity in tissues from POAG patients and an age-related upregulation of autophagy in healthy human TM tissues. In the H2O2-induced aging model, TM cells displayed both elevated autophagic activity and fibrosis. Further investigation showed that enhanced autophagy activity promoted fibrotic progression via activation of the TGF-β2/Smad signaling pathway. Similarly, in the dexamethasone-treated TM cell model, autophagy was found to exacerbate fibrosis, aligning with observations in the aging model. In this study, we uncover the interplay between autophagy and the TGF-β2/Smad pathway in the pathogenesis of POAG. We observed increased autophagic activity in TM tissues from POAG patients and in TM tissues of aging healthy individuals. In human primary TM cells, we confirmed that autophagy becomes activated in the context of cellular senescence and the development of POAG, which further facilitates fibrotic progression via the TGF-β2/Smad signaling pathway. These findings underscore the important role of autophagy in POAG pathogenesis and confirm senescence as a pivotal risk factor.

Graphene Quantum Dots as Antifibrotic Therapy for Kidney Disease.

Graphene quantum dots (GQDs) have received much attention for their biomedical applications, such as bioimaging and drug delivery. Additionally, they have antioxidant and anti-inflammatory properties. We used GQDs to treat renal fibrosis and confirmed their ability to protect renal cells from excessive oxidative stress in vitro and in vivo. Tubulointerstitial fibrosis was induced by unilateral ureteral obstruction (UUO) in 7- to 8-week-old male C57BL/6 mice. GQDs were administered by intravenous injection to mimic clinical treatment. The levels of oxidative stress, ROS production, apoptosis and proinflammatory cytokines and the activity of the TGFβ1/Smad pathway were evaluated after treatment with GQDs. In vitro, rhTGF-β1 was used to induce fibrosis in primary kidney tubule epithelial cells. GQDs alleviated fibrosis and morphological changes after UUO induction. At the mRNA and protein levels, GQDs significantly reduced the expression of fibrotic markers and proinflammatory cytokines, decreased ROS production and TGF-β1 expression, and affected Smad-dependent signaling pathways. In vitro, GQDs inhibited rhTGF-β1-induced epithelial-to-mesenchymal transition in primary kidney tubule epithelial cells and reduced apoptosis and ROS accumulation. This study revealed the role of GQDs in kidney fibrosis: GQDs effectively attenuated major fibrogenesis events by inhibiting ROS accumulation and the vicious cycle of the ROS and TGF-β1/Smad signaling pathways, as well as alleviating cell apoptosis and inflammation. Thus, GQDs may be a therapeutic option for chronic kidney disease progression.

Fibroblast growth factor 21 alleviated atopic march by inhibiting the differentiation of type 2 helper T cells.

The blood FGF21 expression has been previously suggested to increase in patients developing atopic dermatitis (AD) and asthma. However, its impact on atopic march is rarely analyzed. The present work focused on investigating the role of Fibroblast Growth Factor 21(FGF21) in atopic march mice and its underlying mechanisms. The models were induced with Diisononyl phthalate (DINP) and OVA in wild-type C57BL/6 and FGF21-/- mice. RAW264.7 cells were induced by LPS with/without FGF21 or KLB-SiRNA for in vitro analyses. The data indicated that there were more severe allergic reactions including IgE levels and the proportion of mast cells in the blood of FGF21-/- mice in relative to WT model mice during the progression from AD to asthma. However, exogenous administration of FGF21 inhibited allergies. In this study, we reported that FGF21 mitigated AD-like lesions and Th1/2 or Th17/Treg cell imbalance in AD mice, and significantly decreased TSLP, IL-33, IL-4, IL-5, IL-13 and IL-17A expression on skin. During the asthma phase, FGF21 improved airway remodeling by downgrading inflammatory factors IL-4, IL-5, IL-13 and IL-17A; fibrotic markers α-SMA and Collagen I; and oxidative products MDA and ROS in wild-type model mice. Compared with WT model mice, the adverse consequences were aggravated in FGF21-/- asthmatic mice. From the mechanistic perspective, FGF21 suppressed NF-κB/NLRP3, TGF-β1/Smad3 and JNK signaling pathways and increased Nrf2 expression in vivo and in vitro. In addition, β-Klotho knockdown attenuated the ameliorative impact of FGF21 on cellular damage. Blocking AMPKα in the LPS-treated RAW264.7 cells inhibited the reduction of FGF21 and the phosphorylation of JNK. To conclude, FGF21 alleviated atopic march by inhibiting Th2/17 immune response, and reduced airway remodeling by regulating NF-κB/NLRP3, TGF-β1/Smad3 and AMPKα/JNK pathways. Moreover, this study provides a rationale and novel ideas for applying FGF21 in treating AD and asthma.

Retraction notice to "Dulaglutide mitigates high dietary fructose-induced renal fibrosis in rats through suppressing epithelial-mesenchymal transition mediated by GSK-3β/TGF-β1/Smad3 signaling pathways" [Life Sci. 309 (2022) 120999

Retraction notice to "Dulaglutide mitigates high dietary fructose-induced renal fibrosis in rats through suppressing epithelial-mesenchymal transition mediated by GSK-3β/TGF-β1/Smad3 signaling pathways" [Life Sci. 309 (2022) 120999

Kangfuxin solution alleviates esophageal stenosis after endoscopic submucosal dissection: A natural ingredient strategy.

Esophageal stricture ranks among the most significant complications following endoscopic submucosal dissection (ESD). Excessive fibrotic repair is a typical pathological feature leading to stenosis after ESD. To examine the effectiveness and underlying mechanism of Kangfuxin solution (KFX) in mitigating excessive fibrotic repair of the esophagus post-ESD. Pigs received KFX at 0.74 mL/kg/d for 21 days after esophageal full circumferential ESD. Endoscopic examinations occurred on days 7 and 21 post-ESD. In vitro, recombinant transforming growth factor (TGF)-β1 (5 ng/mL) induced a fibrotic microenvironment in primary esophageal fibroblasts (pEsF). After 24 hours of KFX treatment (at 1.5%, 1%, and 0.5%), expression of α-smooth muscle actin-2 (ACTA2), fibronectin (FN), and type collagen I was assessed. Profibrotic signaling was analyzed, including TGF-β1, Smad2/3, and phosphor-smad2/3 (p-Smad2/3). Compared to the Control group, the groups treated with KFX and prednisolone exhibited reduced esophageal stenosis, lower weight loss rates, and improved food tolerance 21 d after ESD. After treatment, Masson staining revealed thinner and less dense collagen fibers in the submucosal layer. Additionally, the expression of fibrotic effector molecules was notably inhibited. Mechanistically, KFX downregulated the transduction levels of fibrotic functional molecules such as TGF-β1, Smad2/3, and p-Smad2/3. In vitro, pEsF exposed to TGF-β1-induced fibrotic microenvironment displayed increased fibrotic activity, which was reversed by KFX treatment, leading to reduced activation of ACTA2, FN, and collagen I. The 1.5% KFX treatment group showed decreased expression of p-Smad 2/3 in TGF-β1-activated pEsF. KFX showed promise as a therapeutic option for post-full circumferential esophageal ESD strictures, potentially by suppressing fibroblast fibrotic activity through modulation of the TGF-β1/Smads signaling pathway.

The Cyclin-Dependent Kinase 8 Inhibitor E966-0530-45418 Attenuates Pulmonary Fibrosis In Vitro and In Vivo.

Pulmonary fibrosis (PF) is a high-mortality lung disease with limited treatment options, highlighting the need for new therapies. Cyclin-dependent kinase 8 (CDK8) is a promising target due to its role in regulating transcription via the TGF-β/Smad pathway, though CDK8 inhibitors have not been thoroughly studied for PF. This study aims to evaluate the potential of E966-0530-45418, a novel CDK8 inhibitor, in mitigating PF progression and explores its underlying mechanisms. We discovered that CDK8 is upregulated in lung tissues from idiopathic pulmonary fibrosis patients and in a bleomycin-induced PF mouse model. Our study further revealed that E966-0530-45418 inhibits PF progression by attenuating the activity of the transcription factor Smad3, which is involved in TGF-β1/Smad signaling, along with RNA polymerase II to downregulate fibrosis-associated protein expression in alveolar epithelia and lung fibroblasts and consequently mitigate myofibroblast differentiation and collagen deposition. E966-0530-45418 also blocks STAT3 signaling to obstruct M2 macrophage polarization, further suppressing PF progression. Moreover, E966-0530-45418 administration ameliorated lung function deterioration and lung parenchymal destruction in the bleomycin-induced PF mouse model. These findings indicate that E966-0530-45418 holds promise as a pioneering CDK8 inhibitor for treating PF.

Dim blue light at night worsens high-fat diet-induced kidney damage via increasing corticosterone levels and modulating the expression of circadian clock genes.

Obesity is a contributing factor that increases the likelihood of developing chronic kidney disease. In recent years, studies have found that light pollution worldwide promoted obesity, which was known to be a consequence of circadian rhythm disruption. Nevertheless, the impact of light pollution on kidney disease associated with obesity remains mostly unknown, and potential processes have been minimally investigated. Herein, we fed mice a high-fat diet and gave them dim white (dWL), blue (dBL), green (dGL), and red (dRL) light for 12 weeks. Our results showed that both dWL and dBL tended to be more susceptible to damage to kidney dysfunction caused by a high-fat diet compared to LD, with more pronounced changes in dBL. The analysis of kidney found that dBL activated the TGF-β1/Smad signaling pathway to promote epithelial-mesenchymal transition (EMT) in the kidney. Additionally, dBL activated the NF-κB signaling pathway and resulted in elevated protein levels of TLR4, p-IκB, p-P65, and TNF-α. Furthermore, dBL increased BAX protein levels and decreased BCL2 protein levels. At the same time, dBL affected the Keap1/Nrf2/HO-1 signaling pathway, elevating KEAP1 and decreasing NRF2 and HO-1 protein levels. We were surprised to find that dBL altered the expression of the circadian clock genes, resulting in a decrease in the positively regulated genes Bmal1, Clock, and an increase in the negatively regulated genes Per1, Per2, Per3. Mechanistically, dBL increased plasma CORT levels as well as decreased renal GR α expression, and in vitro experiments showed that the circadian clock genes were altered by the addition of CORT and returned to normal levels after the addition of the GR inhibitor RU486. Consequently, dBL can exacerbate renal injury by elevating plasma CORT levels and altering rhythmic changes by acting on the biological clock via GR.

Cannabidiol Alleviates Intestinal Fibrosis in Mice with Ulcerative Colitis by Regulating Transforming Growth Factor Signaling Pathway.

The aim of this study is to investigate the protective effect of Cannabidiol (CBD) on DSS-induced colitis in C57BL/6 mice and its related pathways. A mouse model of ulcerative colitis (US) was induced by DSS. Enzyme-linked immunosorbent assay (ELISA), quantitative reverse transcription polymerase-chain reaction (qRT-PCR), Western blot (WB) and immunofluorescence (IF) were used to identify the key factors involved in inflammatory response, oxidative stress and intestinal fibrosis. In addition, we transfected si-RNA into CCD-18Co cells. The research suggests that CBD significantly improves intestinal inflammation by up-regulating the nuclear factor erythroid 2-related factor 2 (Nrf2) expression, inhibiting the classical Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κb) pathway, and inhibiting the release of IL-6 (Interleukin), IL-1β, Tumor Necrosis Factor-α (TNF-α) and other factors. At the same time, CBD plays an antioxidant role by regulating Nrf2/ HO-1 (Heme Oxygenase-1) pathway and activating HO-1 activity. On the other hand, CBD may regulate Transforming growth factor beta (TGF-β)/SMADs signaling pathway by inhibiting the expression of TGF-β1, thereby inhibiting the expression of α-SMA, Collagen1, TIMP1 and other factors, thus playing an anti-fibrotic role. Notably, when Nrf2 is inhibited or lacking, CBD loses the above protective effect against DSS-induced colon injury. CBD affects the classical NF-κb pathway, Nrf2/ Heme Oxygenase-1 (HO-1) pathway, and Transforming growth factor beta (TGF-β)/SMAD pathway by regulating Nrf2, thereby reducing colonic inflammation and oxidative stress and improving the progression of colonic fibrosis.

SIRT2-dependent DKK1 deacetylation aggravates polycystic ovary syndrome by targeting the TGF-β1/Smad3 signaling pathway

Background Polycystic ovarian syndrome (PCOS) is a prevalent metabolic and endocrine condition in females of reproductive age. This work was to discover the underlying role of Dickkopf 1 (DKK1) and its putative regulating mechanism in P COS. Methods Mice recieved dehydroepiandrosterone (DHEA) injection to establish the in vivo P COS model.Hematoxylin and eosin (H&E) staining was performed for histological analysis. RT-qP CR and Western blotting were used to detect gene and protein expression. CCK-8 and flow cytometry assays were applied to detect cell viability and apoptosis. Co-immunoprecipitation (Co-IP) and immunoprecipitation (IP) were applied to assess association between DKK1 and SIRT2. Results In this work, DKK1 is downregulated in P COS rats. It was revealed that DKK1 knockdown induced apoptosis and suppressed proliferation in KGN cells, whereas DKK1 overexpression had exactly the opposite effects. In addition, DKK1 deactivates the T GF-β1/SMad3 signaling pathway, thereby controlling KGN cell proliferation and apoptosis. Besides, SIRT2 inhibition reversed the impact of DKK1 overexpression on KGN cell proliferation and apoptosis. Furthermore, SIRT2 downregulated DKK1 expression by deacetylating DKK1 in KGN cells. Discussion Altogether, we concluded that SIRT2-induced deacetylation of DKK1 triggers T GF-β1/Smad3 hyperactivation, thereby inhibiting proliferation and promoting apoptosis of KGN cells. The above results indicated that DKK1 might function as a latent target for P COS treatment.