Bicyclol attenuates pulmonary fibrosis with silicosis via both canonical and non-canonical TGF-ß1 signaling pathways.

BACKGROUND: Silicosis is an irreversible fibrotic disease of the lung caused by chronic exposure to silica dust, which manifests as infiltration of inflammatory cells, excessive secretion of pro-inflammatory cytokines, and pulmonary diffuse fibrosis. As the disease progresses, lung function further deteriorates, leading to poorer quality of life of patients. Currently, few effective drugs are available for the treatment of silicosis. Bicyclol (BIC) is a compound widely employed to treat chronic viral hepatitis and drug-induced liver injury. While recent studies have demonstrated anti-fibrosis effects of BIC on multiple organs, including liver, lung, and kidney, its therapeutic benefit against silicosis remains unclear. In this study, we established a rat model of silicosis, with the aim of evaluating the potential therapeutic effects of BIC. METHODS: We constructed a silicotic rat model and administered BIC after injury. The FlexiVent instrument with a forced oscillation system was used to detect the pulmonary function of rats. HE and Masson staining were used to assess the effect of BIC on silica-induced rats. Macrophages-inflammatory model of RAW264.7 cells, fibroblast-myofibroblast transition (FMT) model of NIH-3T3 cells, and epithelial-mesenchymal transition (EMT) model of TC-1 cells were established in vitro. And the levels of inflammatory mediators and fibrosis-related proteins were evaluated in vivo and in vitro after BIC treatment by Western Blot analysis, RT-PCR, ELISA, and flow cytometry experiments. RESULTS: BIC significantly improved static compliance of lung and expiratory and inspiratory capacity of silica-induced rats. Moreover, BIC reduced number of inflammatory cells and cytokines as well as collagen deposition in lungs, leading to delayed fibrosis progression in the silicosis rat model. Further exploration of the underlying molecular mechanisms revealed that BIC suppressed the activation, polarization, and apoptosis of RAW264.7 macrophages induced by SiO2. Additionally, BIC inhibited SiO2-mediated secretion of the inflammatory cytokines IL-1ß, IL-6, TNF-α, and TGF-ß1 in macrophages. BIC inhibited FMT of NIH-3T3 as well as EMT of TC-1 in the in vitro silicosis model, resulting in reduced proliferation and migration capability of NIH-3T3 cells. Further investigation of the cytokines secreted by macrophages revealed suppression of both FMT and EMT by BIC through targeting of TGF-ß1. Notably, BIC blocked the activation of JAK2/STAT3 in NIH-3T3 cells required for FMT while preventing both phosphorylation and nuclear translocation of SMAD2/3 in TC-1 cells necessary for the EMT process. CONCLUSION: The collective data suggest that BIC prevents both FMT and EMT processes, in turn, reducing aberrant collagen deposition. Our findings demonstrate for the first time that BIC ameliorates inflammatory cytokine secretion, in particular, TGF-ß1, and consequently inhibits FMT and EMT via TGF-ß1 canonical and non-canonical pathways, ultimately resulting in reduction of aberrant collagen deposition and slower progression of silicosis, supporting its potential as a novel therapeutic agent.

Creg1 Regulates Erythroid Development via TGF-ß/Smad2-Klf1 Axis in Zebrafish.

Understanding the regulation of normal erythroid development will help to develop new potential therapeutic strategies for disorders of the erythroid lineage. Cellular repressor of E1A-stimulated genes 1 (CREG1) is a glycoprotein that has been implicated in the regulation of tissue homeostasis. However, its role in erythropoiesis remains largely undefined. In this study, it is found that CREG1 expression increases progressively during erythroid differentiation. In zebrafish, creg1 mRNA is preferentially expressed within the intermediate cell mass (ICM)/peripheral blood island (PBI) region where primitive erythropoiesis occurs. Loss of creg1 leads to anemia caused by defective erythroid differentiation and excessive apoptosis of erythroid progenitors. Mechanistically, creg1 deficiency results in reduced activation of TGF-ß/Smad2 signaling pathway. Treatment with an agonist of the Smad2 pathway (IDE2) could significantly restore the defective erythroid development in creg1-/- mutants. Further, Klf1, identified as a key target gene downstream of the TGF-ß/Smad2 signaling pathway, is involved in creg1 deficiency-induced aberrant erythropoiesis. Thus, this study reveals a previously unrecognized role for Creg1 as a critical regulator of erythropoiesis, mediated at least in part by the TGF-ß/Smad2-Klf1 axis. This finding may contribute to the understanding of normal erythropoiesis and the pathogenesis of erythroid disorders.

Epimedium-Curculigo herb pair enhances bone repair with infected bone defects and regulates osteoblasts through LncRNA MALAT1/miR-34a-5p/SMAD2 axis.

Infected bone defects (IBDs) are the common condition in the clinical practice of orthopaedics. Although surgery and anti-infective medicine are the firstly chosen treatments, in many cases, patients experience a prolonged bone union process after anti-infective treatment. Epimedium-Curculigo herb pair (ECP) has been proved to be effective for bone repair. However, the mechanisms of ECP in IBDs are insufficiency. In this study, Effect of ECP in IBDs was verified by micro-CT and histological examination. Qualitative and quantitative analysis of the main components in ECP containing medicated serum (ECP-CS) were performed. The network pharmacological approaches were then applied to predict potential pathways for ECP associated with bone repair. In addition, the mechanism of ECP regulating LncRNA MALAT1/miRNA-34a-5p/SMAD2 signalling axis was evaluated by molecular biology experiments. In vivo experiments indicated that ECP could significantly promote bone repair. The results of the chemical components analysis and the pathway identification revealed that TGF-ß signalling pathway was related to ECP. The results of in vitro experiments indicated that ECP-CS could reverse the damage caused by LPS through inhibiting the expressions of LncRNA MALAT1 and SMAD2, and improving the expressions of miR-34a-5p, ALP, RUNX2 and Collagen type І in osteoblasts significantly. This research showed that ECP could regulate the TGF-ß/SMADs signalling pathway to promote bone repair. Meanwhile, ECP could alleviate LPS-induced bone loss by modulating the signalling axis of LncRNA MALAT1/miRNA-34a-5p/ SMAD2 in IBDs.

Naringin inhibits cisplatin resistance of ovarian cancer cells by inhibiting autophagy mediated by the TGF-ß2/smad2 pathway.

Background: Resistance to cisplatin (DDP) in patients with ovarian cancer (OC) poses a great challenge to improving the quality of life of patients. Past reports have revealed that naringin can induce apoptosis of OC cells and delay the occurrence of drug resistance in OC cells. However, the molecular role by which naringin inhibits DDP resistance in OC has not been definitively proven by researchers. The objective of this study is to investigate the effect of naringin on DDP resistance in OC cells and the specific mechanism of naringin mediating autophagy. Methods: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry were selected to evaluate the role of naringin or DDP on the proliferation and apoptosis of human OC cells (SKOV3/A2780). The protein levels of Sequestosome 1 (SQSTM1/p62, hereinafter referred to as p62), microtubule-associated protein 1 light chain 3 (LC3), transforming growth factor-ß2 (TGF-ß2) and SMAD family member 2 (smad2) were detected with Western blotting assay. Immunofluorescence assay was also used to evaluate the level of LC3 in different groups of cells. Besides, functional analyses were performed in vivo. Results: Naringin was shown to promote DDP sensitivity and apoptosis of human OC DDP-resistant cell line (SKOV3/A2780-DDP cells). Significantly increased p62 expression and reduced LC3 expression were found in naringin-treated cells. The autophagy agonist, rapamycin, reversed the effect of naringin on the resistance of SKOV3-DDP cells to DDP. Naringin inhibited levels of TGF-ß2/smad2 pathway-related proteins, and regulated autophagy in SKOV3-DDP cells. In vivo experiments demonstrated that injection of naringin inhibited DDP resistance and autophagy in mice xenograft model. Conclusions: In summary, naringin inhibits DDP resistance in OC cells by inhibiting autophagy mediated by the TGF-ß2/smad2 pathway.

Lrba participates in the differentiation of IgA+ B lymphocytes through TGFßR signaling.

Introduction: Lrba is a cytoplasmic protein involved in vesicular trafficking. Lrba-deficient (Lrba-/-) mice exhibit substantially higher levels of IgA in both serum and feces than wild-type (WT) mice. Transforming growth factor ß1 (TGFß1) and its receptors (TGFßR I and II) is essential for differentiating IgA+ B cells. Furthermore, increased IgA production suggests a potential connection between Lrba and the TGFßR signaling pathway in IgA production. However, the specific function of Lrba in B cell biology remains unknown. Aim: Given the increased IgA levels in Lrba-/- mice, the goal in this work was to explore the lymph organs where the switch to IgA occurs, and if TGFßR function is affected. Methods: Non-immunized Lrba-/- mice were compared with Lrba+/+ mice. IgA levels in the serum and feces, as well as during peripheral B cell development, were determined. IgA+ B cells and plasma cells were assessed in the small intestine and secondary lymphoid organs, such as the spleen, mesenteric lymph nodes, and Peyer's patches. The TGFßR signaling pathway was evaluated by determining the expression of TGFßR on B cells. Additionally, SMAD2 phosphorylation was measured under basal conditions and in response to recombinant TGFß. Finally, confocal microscopy was performed to investigate a possible interaction between Lrba and TGFßR in B cells. Results: Lrba-/- mice exhibited significantly higher levels of circulating IgA, IgA+ B, and plasma cells than in peripheral lymphoid organs those in WT mice. TGFßR expression on the membrane of B cells was similar in both Lrba-/- and Lrba+/+ mice. However, intracellular TGFßR expression was reduced in Lrba-/- mice. SMAD2 phosphorylation showed increased levels under basal conditions; stimulation with recombinant TGFß elicited a poorer response than in that in Lrba+/+ B cells. Finally, we found that Lrba colocalizes with TGFßR in B cells. Conclusion: Lrba is essential in controlling TGFßR signaling, subsequently regulating SMAD2 phosphorylation on B cells. This mechanism may explain the increased differentiation of IgA+ B cells and production of IgA-producing plasma cells.

Low frequency of repetitive trans-spinal magnetic stimulation promotes functional recovery after spinal cord injury in mice through inhibiting TGF-ß1/Smad2/3 signaling pathway.

Spinal cord injury (SCI) remains a worldwide challenge due to limited treatment strategies. Repetitive trans-spinal magnetic stimulation (rTSMS) is among the most cutting-edge treatments for SCI. However, the mechanism underlying rTSMS on functional recovery is still unclear. In this study, 8-week-old C57BL/6J female mice were used to design SCI models followed by treatment with monotherapy (1 Hz rTSMS or LY364947) or combination therapy (rTSMS + LY364947). Our results showed obvious functional recovery after monotherapies compared to untreated mice. Immunofluorescence results demonstrated that rTSMS and LY364947 modulate the lesion scar by decreasing fibrosis and GFAP and possess the effect on neural protection. In addition, rTSMS suppressed inflammation and the activation of TGFß1/Smad2/3 signaling pathway, as evidenced by markedly reduced TGF-ßRⅠ, Smad2/3, and p-Smad2/3 compared with untreated mice. Overall, it was confirmed that 1 Hz rTSMS promotes SCI recovery by suppressing the TGFß1/Smad2/3 signaling, revealing a novel pathological mechanism of 1 Hz rTSMS intervention, and may provide potential targets for clinical treatment.

G protein-coupled receptor kinase 2 as a novel therapeutic target for gland fibrosis of Sjögren's syndrome.

Sjogren's syndrome (SS) is a chronic, progressive autoimmune disorder characterized by gland fibrosis. We previously found a close correlation between gland fibrosis and the expression of G protein-coupled receptor kinase 2 (GRK2). In this study we explored the pathological and therapeutic significance of GRK2 in SS. Submandibular gland (SMG) antigen-induced SS mouse model was established in WT and GRK2+/- mice. We showed that the expression levels of GRK2 were significantly up-regulated in glandular tissue and positively correlated with fibrotic morphology in SS patients and mice. Hemizygous knockout of GRK2 significantly inhibited the gland fibrosis. In mouse salivary gland epithelial cells (SGECs), we demonstrated that GRK2 interacted with Smad2/3 to positively regulate the activation of TGF-ß-Smad signaling with a TGF-ß-GRK2 positive feedback loop contributing to gland fibrosis. Hemizygous knockout of GRK2 attenuated TGF-ß-induced collagen I production in SGECs in vitro and hindered gland fibrosis in murine SS though preventing Smad2/3 nuclear translocation. Around 28 days post immunization with SMG antigen, WT SS mice were treated with a specific GRK2 inhibitor paroxetine (Par, 5 mg·kg-1·d-1, i.g. for 19 days). We found that Par administration significantly attenuated gland fibrosis and alleviated the progression of SS in mice. We conclude that genetic knockdown or pharmacological inhibition of GRK2 significantly attenuates gland fibrosis and alleviates the progression of SS. GRK2 binds to Smad2/3 and positively regulates the activation of TGF-ß-Smad signaling. A TGF-ß-GRK2 positive feedback loop contributes to gland fibrosis. Our research points out that GRK2 could be a promising therapeutic target for treating SS.

Isorhamnetin inhibits hypertrophic scar formation through TGF-ß1/Smad and TGF-ß1/CREB3L1 signaling pathways.

Background: Hypertrophic scar (HS) is a common fibrotic skin disease that occurs secondary to burns or injuries. The activation of the TGF-ß signaling pathway contributes immensely to HS formation. Isorhamnetin (ISO) is a type of flavonoid compound that exerts an antifibrotic effect via TGF-ß signaling suppression. However, whether ISO can inhibit HS formation via TGF-ß signaling is yet to be elucidated. This study aimed to examine the influence of ISO on HS pathogenesis and TGF-ß signaling, especially the downstream molecules and networks of TGF-ß signaling that facilitate HS formation. Methods: Hypertrophic scar fibroblasts (HSFBs) were isolated from human HS tissues. The in vitro proliferation, migration, contractile ability, cell cycle, and apoptosis of HSFBs after ISO treatment were determined using cell viability assay, EdU staining, wound healing assay, collagen gel contraction assay, and flow cytometry. The expressions of genes and proteins involved in TGF-ß signaling and its downstream molecules in ISO-treated HSFBs were determined using quantitative PCR (qPCR), immunofluorescence, and western blotting. In vivo, a rabbit HS model was established, and the effects of ISO on rabbit HS formation were investigated using histological analysis, immunohistochemical staining, and qPCR. Results: In vitro studies indicated that ISO treatment suppressed the proliferation, migration, and contractile ability of HSFBs; attenuated the expressions of COL Ⅰ, COL Ⅲ, and α-SMA; and inhibited TGF-ß1 signaling-induced activation of HSFBs by decreasing the levels of phosphorylated Smad2/3 and cleaved CREB3L1 in a dose-dependent manner. Furthermore, ISO augmented apoptosis and G2 phase cell cycle arrest of HSFBs by upregulating the expressions of the proapoptotic proteins Bax and cleaved caspase-3 and downregulating the expression of the antiapoptotic protein Bcl-2. In vivo studies revealed that ISO ameliorated HS formation in the rabbit ear by lowering the scar elevation index, attenuating the collagen density, facilitating the regular arrangement of collagen fibers, and downregulating the expressions of TGF-ß1, CREB3L1, COL Ⅰ, COL Ⅲ, and α-SMA. Conclusions: ISO suppressed HS pathogenesis by dampening TGF-ß1/Smad and TGF-ß1/CREB3L1 signaling pathways, which suggests that it may serve as a candidate inhibitor of TGF-ß1 signaling and a promising anti-HS drug with a high therapeutic potential.

Leucine rich α2 glycoprotein 1 derived from malignant pleural mesothelioma cells facilitates macrophage M2 phenotypes.

Background: Macrophages constitute the main part of infiltrating immune cells in Malignant pleural mesothelioma (MPM) and abnormally high ratios of M2 macrophages are present in both pleural effusion and tissue samples of MPM patients. Whether MPM cells affect formation of M2 macrophages is poorly understood. In this study, we focused on identification of MPM-cells-derived soluble factors with M2-promoting effects. Methods: Media of malignant pleural mesothelioma cells were collected and soluble factors affecting macrophages were analyzed by mass spectrometry. TGF-ß receptor inhibitor SB431542 was used as the entry point to explore the downstream mechanism of action by qRT-PCR, WB and immunofluorescence. Results: The serum-free culture media collected from the human MPM cells Meso1 and Meso2 significantly enhanced expression of the M2 signature molecules including IL-10, TGF-ß and CD206 in the human macrophages THP-1, while the culture medium of the human MPM cells H2452 did not show such M2-promoting effects. Analysis of proteins by mass spectrometry and ELISA suggested that Leucine rich α2 glycoprotein 1(LRG1) was a potential candidate. LRG1 time- and dose-dependently increased expression of the M2 signature molecules, confirming its M2-promoting effects. Furthermore, LRG1's M2-promoting effects were reduced by the TGF-ß receptor inhibitor SB431542, and LRG1 increased phosphorylation of Smad2, indicating that M2-promoting effects of LRG1 were via the TGF-ß receptor/Smad2 signaling pathway. Conclusions: Our results provide a potential M2-promoting new member, LRG1, which contributes to the immune escape of MPM via the TGF-ß receptor/Smad2 signaling pathway.

MiR-21 regulates skeletal muscle atrophy and fibrosis by targeting TGF-beta/SMAD7-SMAD2/3 signaling pathway.

Long-term denervation-induced atrophy and fibrosis of skeletal muscle due to denervation leads to poor recovery of muscle function. Studies have shown that the transforming growth factor-ß1 (TGF-ß1)-Smad signaling pathway plays a central role in muscle atrophy and fibrosis. Recent studies demonstrate the role of microRNAs (miRs) in various pathological conditions, including muscle regeneration. miR-21 has been shown to play a dynamic role in inflammatory responses and in accelerating injury responses to fibrosis. We used both RNA sequencing and quantitative RT-PCR strategies to examine the alternations of miRNAs during denervation-induced gastrocnemius muscle atrophy and fibrosis. Our data showed that MiR-21 was upregulated in denervated gastrocnemius muscle tissue, and TGF-ß1treatment increased miR-21 expression. Inhibition of miR-21 reduced gastrocnemius muscle fibrosis and significantly downregulated the expression of p-SMAD2/3 and the fibrosis-associated markers TGF-ß1, connective tissue growth factor, alpha smooth muscle actin. Masson's trichrome staining revealed that atrophy and fibrosis in gastrocnemius muscle tissue were reduced in the miR-21 inhibition group compared to the control group. We confirmed that SMAD7 is a direct target of miR-21 using a dual luciferase assay. Furthermore, Immunofluorescence and Western blot analyses revealed that miR-21 inhibition reduced SMAD2/3 phosphorylation and nuclear translocation. While SMAD7-siRNA abolished the effect. Consequently, the discovery that miR-21 regulates the atrophy and fibrosis of the gastrocnemius muscle offers a possible therapeutic approach for their management.

RHBDF1 modulates cisplatin sensitivity of small cell lung cancer through YAP1/Smad2 signaling pathway.

Small cell lung cancer (SCLC) is a fatal tumor type that is prone to drug resistance. In our previous study, we showed that human rhomboid-5 homolog-1 (RHBDF1) was differentially expressed in 5 intrinsic cisplatin-resistant SCLC tissues compared with 5 intrinsic cisplatin-sensitive SCLC tissues by RNA sequencing, which intrigued us. We performed gain- and loss-of-function experiments to investigate RHBDF1 function, bioinformatics analysis, qRT-PCR, western blotting, and immunoprecipitation to elucidate the molecular mechanisms as well as detect RHBDF1 expression in SCLC by immunohistochemistry. We found that RHBDF1 knockdown promoted cell proliferation and cisplatin chemoresistance and inhibited apoptosis in vitro and in vivo. These effects could be reversed by overexpressing RHBDF1 in vitro. Mechanistically, RHBDF1 interacted with YAP1, which increased the phosphorylation of Smad2 and transported Smad2 to the nucleus. Among clinical specimens, the RHBDF1 was a low expression in SCLC and was associated with clinicopathological features and prognosis. We are the first to reveal that RHBDF1 inhibited cell proliferation and promoted cisplatin sensitivity in SCLC and elucidate a novel mechanism through RHBDF1/YAP1/Smad2 signaling pathway which played a crucial role in cisplatin chemosensitivity. Targeting this pathway can be a promising therapeutic strategy for chemotherapy resistance in SCLC.

Marrow mesenchymal stem cell mediates diabetic nephropathy progression via modulation of Smad2/3/WTAP/m6A/ENO1 axis.

Diabetic nephropathy (DN) is one of the common microvascular complications in diabetic patients. Marrow mesenchymal stem cells (MSCs) have attracted attention in DN therapy but the underlying mechanism remains unclear. Here, we show that MSC administration alleviates high glucose (HG)-induced human kidney tubular epithelial cell (HK-2 cell) injury and ameliorates renal injury in DN mice. We identify that Smad2/3 is responsible for MSCs-regulated DN progression. The activity of Smad2/3 was predominantly upregulated in HG-induced HK-2 cell and DN mice and suppressed with MSC administration. Activation of Smad2/3 via transforming growth factor-ß1 (TGF-ß1) administration abrogates the protective effect of MSCs on HG-induced HK-2 cell injury and renal injury of DN mice. Smad2/3 has been reported to interact with methyltransferase of N6-methyladenosine (m6A) complex and we found a methyltransferase, Wilms' tumor 1-associating protein (WTAP), is involved in MSCs-Smad2/3-regulated DN development. Moreover, WTAP overexpression abrogates the improvement of MSCs on HG-induced HK-2 cell injury and renal injury of DN mice. Subsequently, α-enolase (ENO1) is the downstream target of WTAP-mediated m6A modification and contributes to the MSCs-mediated regulation. Collectively, these findings reveal a molecular mechanism in DN progression and indicate that Smad2/3/WTAP/ENO1 may present a target for MSCs-mediated DN therapy.

Dang-Gui-Si-Ni decoction facilitates wound healing in diabetic foot ulcers by regulating expression of AGEs/RAGE/TGF-ß/Smad2/3.

Diabetic foot ulcer (DFU) is a predominant complication of diabetes mellitus with poor prognosis accompanied by high amputation and mortality rates. Dang-Gui-Si-Ni decoction (DSD), as a classic formula with a long history in China, has been found to improve DFU symptoms. However, mechanism of DSD for DFU therapy remains unclear with no systematic elaboration. In vivo, following establishment of DFU rat model, DSD intervention with low, medium and high doses was done, with Metformin (DM) as a positive control group. With wound healing detection, pathological changes by HE staining, inflammatory factor expression by ELISA and qRT-PCR, oxidative stress levels by ELISA, and AGEs/RAGE/TGF-ß/Smad2/3 expression by Western blot were performed. In vitro, intervention with LY2109761 (TGF-ß pathway inhibitor) based on DSD treatment in human dermal fibroblast-adult (HDF-a) cells was made. Cell viability by CCK8, migration ability by cell scratch, apoptosis by flow cytometry, and AGEs/RAGE/TGF-ß/Smad2/3 expression by Western blot were measured. DFU rats exhibited elevated AGEs/RAGE expression, whereas decreased TGF-ß1 and p-Smad3/Smad3 protein expression, accompanied by higher IL-1ß, IL-6, TNF-α levels, and oxidative stress. DSD intervention reversed above effects. Glucose induction caused lower cell viability, migration, TGF-ß1 and p-Smad3/Smad3 protein expression, with increased apoptosis and AGEs/RAGE expression in HDF-a cells. These effects were reversed after DSD intervention, and further LY2109761 intervention inhibited DSD effects in cells. DSD intervention may facilitate wound healing in DFU by regulating expression of AGEs/RAGE/TGF-ß/Smad2/3, providing scientific experimental evidence for DSD clinical application for DFU therapy.

Dysregulation of exosomal miRNAs and their related genes in head and neck cancer patients.

Aim: The present study aimed to figure out the potential role of exosomal microRNAs, and their targeted genes in HNC detection/diagnosis. Methods: In the present study, exosomes were extracted from the serum samples of 400 HNC patients and 400 healthy controls. Exosomes were characterized using TEM, NTA, TEM-immunogold labeling and ELISA. Quantitative PCR was used to measure the expression level of exosomal miRNA-19a, miRNA-19b and targeted genes SMAD2 and SMAD4 in HNC patients and controls. Results: The deregulation of miR-19a (p < 0.01), miR-19b (p < 0.03), SMAD2 (p < 0.04) and SMAD4 (p < 0.04) was observed in HNC patients vs controls. Conclusion: ROC curve and Kaplan-Meier analysis showed the good diagnostic/prognostic value of selected exosomal microRNAs and related genes in HNC patients.

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CircZfp644-205 inhibits osteoblast differentiation and induces apoptosis of pre-osteoblasts via sponging miR-455-3p and promoting SMAD2 expression.

BACKGROUND: Circular RNAs (circRNAs) are involved in the progression of osteoporosis; however, their impact on osteogenic differentiation has yet to be fully elucidated. In this study, we identified a novel circRNA known as circZfp644-205 and investigated its effect on osteogenic differentiation and apoptosis in osteoporosis. METHODS: CircZfp644-205, miR-445-3p, and SMAD2 levels were measured using quantitative real-time polymerase chain reaction (qRT-PCR). MC3T3-E1 cells were subjected to microgravity (MG) to establish a cell model. Osteogenic differentiation was assessed using qRT-PCR, Alizarin Red S staining, alkaline phosphatase staining, and western blot. The apoptosis was evaluated using flow cytometry. The relationship between miR-445-3p and circZfp644-205 or SMAD2 was determined using bioinformatics, RNA pull-down, and luciferase reporter assay. Moreover, a hindlimb unloading mouse model was generated to investigate the role of circZfp644-205 in vivo using Micro-CT. RESULTS: CircZfp644-205 expression was up-regulated significantly in HG-treated MC3T3-E1 cells. Further in vitro studies confirmed that circZfp644-205 knockdown inhibited the osteogenic differentiation and induced apoptosis of pre-osteoblasts. CircZfp644-205 acted as a sponge for miR-455-3p, which reversed the effects of circZfp644-205 on pre-osteoblasts. Moreover, miR-455-3p directly targeted SMAD2, thus inhibiting the expression of SMAD2 to regulate cellular behaviors. Moreover, circZfp644-205 alleviated the progression of osteoporosis in mice. CONCLUSIONS: This study provides a novel circRNA that may serve as a potential therapeutic target for osteoporosis and expands our understanding of the molecular mechanism underlying the progression of osteoporosis.

Human Genetics of Ventricular Septal Defect.

Ventricular septal defects (VSDs) are recognized as one of the commonest congenital heart diseases (CHD), accounting for up to 40% of all cardiac malformations, and occur as isolated CHDs as well as together with other cardiac and extracardiac congenital malformations in individual patients and families. The genetic etiology of VSD is complex and extraordinarily heterogeneous. Chromosomal abnormalities such as aneuploidy and structural variations as well as rare point mutations in various genes have been reported to be associated with this cardiac defect. This includes both well-defined syndromes with known genetic cause (e.g., DiGeorge syndrome and Holt-Oram syndrome) and so far undefined syndromic forms characterized by unspecific symptoms. Mutations in genes encoding cardiac transcription factors (e.g., NKX2-5 and GATA4) and signaling molecules (e.g., CFC1) have been most frequently found in VSD cases. Moreover, new high-resolution methods such as comparative genomic hybridization enabled the discovery of a high number of different copy number variations, leading to gain or loss of chromosomal regions often containing multiple genes, in patients with VSD. In this chapter, we will describe the broad genetic heterogeneity observed in VSD patients considering recent advances in this field.

ETV4 promotes the progression of cholangiocarcinoma by regulating glycolysis via the TGF-ß signaling.

BACKGROUND: Considerable studies show that ETS variant 4 (ETV4) plays an important roles in multitudinous tumor. This study investigated its function in cholangiocarcinoma (CCA) progression and revealed the underlying mechanisms. METHODS: The expression of ETV4 in CCA was evaluated using TCGA database and the single-cell analysis based on GSE189903 dataset. ETV4 expression in CCA human specimens was detected by reverse transcription-quantitative PCR, immunohistochemistry, and western blot. Cell Counting Kit-8, EdU, colony formation, wound healing, and Transwell assays were used to analyze the effects of ETV4. Extracellular acidification rate, oxygen consumption rate, glucose uptake, and lactate production were used to measure glycolysis in CAA cells. Western blot was performed to explore glycolysis-related proteins. Tumor growth was evaluated in mice xenograft tumors. RESULTS: ETV4 was up-regulated in CCA epithelial cells. The high-expression of ETV4 was associated with poor prognosis of patients with CCA. ETV4 overexpression enhanced the proliferation, migration, invasion, and glycolysis of CCA cells; ETV4 silencing led to the contrary effects. Mechanistically, ETV4 activates TGF-ß/Smad2/3 signaling pathway. In mice xenograft mode, ETV4 silencing inhibits the tumor growth, the expression of glycolysis-related proteins and TGF-ß/Smad2/3 pathway proteins. CONCLUSIONS: ETV4 functions as an essential factor in the roles of TGF-ß1 in CCA cells, and may be a promising target for TGF-ß1-mediated CCA progression.

Fusobacterium nucleatum-infected periodontitis promotes renal interstitial fibrosis in rats through the TGF-ß/SMAD2/3 and ß-catenin signaling pathways.

OBJECTIVES: Periodontitis is associated with Fusobacterium nucleatum (F.n) infection. Although the colonization of renal tissue by F.n is well documented, its specific role in kidney disease has yet to be determined. This study aimed to investigate the potential association between F.n-induced periodontitis and renal interstitial fibrosis. METHODS: The rat gingival sulcus was injected with F.n suspension, while the control group (NC) was injected with PBS. The levels of total protein (TP), albumin (ALB), creatinine, and urea nitrogen (BUN) in rat serum and/or urine were quantified using the appropriate kits. Renal interstitial fibrosis and epithelial-mesenchymal transition (EMT) were evaluated in rats using Masson staining, Periodic Schiff-Methenamine (PASM) staining, and immunohistochemical staining. The levels of fibrosis- and EMT-related proteins and the TGF-ß/SMAD2/3 and ß-catenin signaling pathways were determined using Western blot analysis. F.n in the kidney tissues was quantitatively determined using bacterial 16S rRNA technology. RESULTS: Serum levels of TP, ALB, creatinine, and BUN were not significantly decreased in F.n-infected rats with periodontitis. The levels of creatinine and ALB in the urine were not statistically different between two groups. Masson and PASM staining showed that F.n-induced periodontitis could promote renal interstitial fibrosis in rats. The levels of collagen I, fibronectin (FN), vimentin, and α-SMA were upregulated in the kidney tissues of rats with F.n-induced periodontitis and in F.n-treated HK-2 cells. However, E-cadherin levels were reduced. F.n promoted renal interstitial and HK-2 cell fibrosis in rats by modulating the TGF-ß/SMAD2/3 and ß-catenin signaling pathways. F.n colonization increased renal interstitial fibrosis in rats. CONCLUSION: F.n-induced periodontitis promoted EMT by activating the TGF-ß/SMAD2/3 and ß-catenin signaling pathways, thus promoting renal interstitial fibrosis in rats.

The circular RNA hsa_circ_0045800 serves as a favorable biomarker in pathogenesis of sjögren's syndrome.

BACKGROUND: Circular RNAs (circRNAs) play various roles in the development of many autoimmune diseases. However, their expression profiles and specific function in Sjögren's Syndrome remains largely unknown. OBJECTIVES: We aimed to investigate circRNAs potential diagnostic value in primary Sjögren's syndrome (pSS) and contribution to the pathogenesis of pSS. METHODS: This study included 102 subjects, 51 pSS patients and 51 healthy controls. The concentration of hsa_circ_0045800 was analyzed in peripheral blood mononuclear cells obtained from 51 pSS patients and 51 healthy controls by qRT-PCR. We established a receiver operating characteristic curve (ROC) to assess the biological diagnostic value of hsa_circ_0045800 for pSS. In addition, we analyzed the correlation between hsa_circ_0045800 and disease activity in Sjogren's syndrome. A differential analysis was also conducted on the concentration of hsa_circ_0045800 in patients in pSS patients before and after treatment. We studied the downstream mechanism of hsa_circ_0045800 through bioinformatics analysis and confirmed it using luciferase reporter gene assay. RESULTS: We confirmed that the concentration of hsa_circ_0045800 was elevated 10.4-fold in peripheral blood mononuclear cells of pSS patients than in healthy controls (p = 0.00). In the pSS active disease group, the concentration of hsa_circ_0045800 is 2.5-fold higher compared to the pSS non-active disease group (p = 0.04). The concentration of hsa_circ_0045800 after treatment was decreased by 80% compared with that before treatment (p = 0.037), suggesting its utility as a potential marker for monitoring treatment efficacy. ROC curve analysis showed that the diagnostic value of hsa_circ_0045800 in pSS patients was significantly higher than that in healthy controls, with an area under the curve of 0.865, a sensitivity of 74%, and a specificity of 92%. The concentration of hsa_circ_0045800 is correlated with various clinical factors: the concentration of hsa_circ_0045800 is positively associated with age (r = 0.328, P = 0.019), oral dryness (r = 0.331, P = 0.017), while it is negatively correlated with HGB (r = -0.435, P = 0.001) and and hypothyroidism (r = -0.318, P = 0.023). Bioinformatics predictions and luciferase assays indicated that hsa_circ_0045800 acts as a molecular sponge for miR-1247-5p, with SMAD2 being a target gene of miR-1247-5p. CONCLUSION: Our study results show that hsa_circ_0045800 potentially contributes to the development and progression of pSS via the miR-1247-5p/SMAD2 pathway. Peripheral blood mononuclear cells are directly involved in the pathogenesis of pSS, and the discovery of hsa_circ_0045800 in peripheral blood mononuclear cells highlights its potential as a novel biomarker for disease activity and diagnosis in patients with pSS. Key Points • The concentration of hsa_circ_0045800 was higher in peripheral blood mononuclear cells of pSS patients. • Hsa_circ_0045800 promoted pSS progression through miR-1247-5p-SMAD2 axis. • Hsa_circ_0045800 is a potential biomarker for pSS.

Role of TRIM59 in regulating PPM1A in the pathogenesis of silicosis and the intervention effect of tanshinone IIA.

This study examines the involvement of TRIM59 in silica-induced pulmonary fibrosis and explores the therapeutic efficacy of Tanshinone IIA (Tan IIA). In vivo experiments conducted on rats with silica-induced pulmonary fibrosis unveiled an increase in TRIM59 levels and a decrease in PPM1A levels. Subsequent investigations using in vitro silicosis cell models demonstrated that modulation of TRIM59 expression significantly impacts silicosis fibrosis, influencing the levels of PPM1A and activation of the Smad2/3 signaling pathway. Immunofluorescence and co-immunoprecipitation assays confirmed the interaction between TRIM59 and PPM1A in fibroblasts, wherein TRIM59 facilitated the degradation of PPM1A protein via proteasomal and ubiquitin-mediated pathways. Furthermore, employing a rat model of silica-induced pulmonary fibrosis, Tan IIA exhibited efficacy in mitigating lung tissue damage and fibrosis. Immunohistochemical analysis validated the upregulation of TRIM59 and downregulation of PPM1A in silica-induced pulmonary fibrosis, which Tan IIA alleviated. In vitro studies elucidated the mechanism by which Tan IIA regulates the Smad2/3 signaling pathway through TRIM59-mediated modulation of PPM1A. Treatment with Tan IIA in silica-induced fibrosis cell models resulted in concentration-dependent reductions in fibrotic markers and attenuation of relevant protein expressions. Tan IIA intervention in silica-induced fibrosis cell models mitigated the TRIM59-induced upregulation of fibrotic markers and enhanced PPM1A expression, thereby partially reversing Smad2/3 activation. Overall, the findings indicate that while overexpression of TRIM59 may activate the Smads pathway by suppressing PPM1A expression, treatment with Tan IIA holds promise in counteracting these effects by inhibiting TRIM59 expression.