Fraxetin pretreatment alleviates cisplatin-induced kidney injury by antagonizing autophagy and apoptosis via mTORC1 activation.

Cisplatin-induced kidney injury (CKI) is a common complication of chemotherapy. Fraxetin, derived from Fraxinus bungeana A. DC. bark, has antioxidant, anti-inflammatory, and anti-fibrotic effects. This study aims to investigate fraxetin's effects on CKI and its underlying mechanism in vivo and in vitro. Tubular epithelial cells (TECs) and mice were exposed to cisplatin with and without fraxetin preconditioning assess fraxetin's role in CKI. TECs autophagy was observed using transmission electron microscopy. Apoptosis levels in animal tissues were measured using TUNEL staining. The protective mechanism of fraxetin was explored through pharmacological and genetic regulation of mTORC1. Molecular docking was used to identify potential binding sites between fraxetin and mTORC1. The results indicated that fraxetin pretreatment reduced cisplatin-induced kidney injury in a time- and concentration-dependent way. Fraxetin also decreased autophagy in TECs, as observed through electron microscopy. Tissue staining confirmed that fraxetin pretreatment significantly reduced cisplatin-induced apoptosis. Inhibition of mTORC1 using rapamycin or siRNA reversed the protective effects of fraxetin on apoptosis and autophagy in cisplatin-treated TECs, while activation of mTORC1 enhanced fraxetin's protective effect. Molecular docking analysis revealed that fraxetin can bind to HEAT-repeats binding site on mTORC1 protein. In  summary, fraxetin pretreatment alleviates CKI by antagonizing autophagy and apoptosis via mTORC1 activation. This provides evidence for the potential therapeutic application of fraxetin in CKI.

Smad4 regulates TGF-ß1-mediated hedgehog activation to promote epithelial-to-mesenchymal transition in pancreatic cancer cells by suppressing Gli1 activity.

Pancreatic cancer (PC) is an aggressive and metastatic gastrointestinal tumor with a poor prognosis. Persistent activation of the TGF-ß/Smad signaling induces PC cell (PCC) invasion and infiltration via epithelial-to-mesenchymal transition (EMT). Hedgehog signaling is a crucial pathway for the development of PC via the transcription factors Gli1/2/3. This study aimed to investigate the underlying molecular mechanisms of action of hedgehog activation in TGF-ß1-triggered EMT in PCCs (PANC-1 and BxPc-3). In addition, overexpression and shRNA techniques were used to evaluate the role of Smad4 in TGF-ß1-treated PCCs. Our data showed that TGF-ß1 promoted PCC invasion and infiltration via Smad2/3-dependent EMT. Hedgehog-Gli signaling axis in PCCs was activated upon TGF-ß1 stimulation. Inhibition of hedgehog with cyclopamine effectively antagonized TGF-ß1-induced EMT, thereby suggesting that the hedgehog signaling may act as a downstream cascade signaling of TGF-ß1. As a key protein that assists the nuclear translocation of Smad2/3, Smad4 was highly expressed in PANC-1 cells, but not in BxPc-3 cells. Conversely, Gli1 expression was low in PANC-1 cells, but high in BxPc-3 cells. Furthermore, knockdown of Smad4 in PANC-1 cells by shRNA inhibited TGF-ß1-mediated EMT and collagen deposition. Overexpression of Smad4 did not affect TGF-ß1-mediated EMT due to the lack of significant increase in nuclear expression of Smad4. Importantly, Gli1 activity was upregulated by Smad4 knockdown in PANC-1 cells and downregulated by Smad4 overexpression in BxPc-3 cells, indicating that Gli1 may be a negative target protein downstream of Smad4. Thus, Smad4 regulates TGF-ß1-mediated hedgehog activation to promote EMT in PCCs by suppressing Gli1 activity.

Investigating the impact of inflammatory response-related genes on renal fibrosis diagnosis: a machine learning-based study with experimental validation.

Renal fibrosis plays a crucial role in the progression of renal diseases, yet the lack of effective diagnostic markers poses challenges in scientific and clinical practices. In this study, we employed machine learning techniques to identify potential biomarkers for renal fibrosis. Utilizing two datasets from the GEO database, we applied LASSO, SVM-RFE and RF algorithms to screen for differentially expressed genes related to inflammatory responses between the renal fibrosis group and the control group. As a result, we identified four genes (CCL5, IFITM1, RIPK2, and TNFAIP6) as promising diagnostic indicators for renal fibrosis. These genes were further validated through in vivo experiments and immunohistochemistry, demonstrating their utility as reliable markers for assessing renal fibrosis. Additionally, we conducted a comprehensive analysis to explore the relationship between these candidate biomarkers, immunity, and drug sensitivity. Integrating these findings, we developed a nomogram with a high discriminative ability, achieving a concordance index of 0.933, enabling the prediction of disease risk in patients with renal fibrosis. Overall, our study presents a predictive model for renal fibrosis and highlights the significance of four potential biomarkers, facilitating clinical diagnosis and personalized treatment. This finding presents valuable insights for advancing precision medicine approaches in the management of renal fibrosis.Communicated by Ramaswamy H. Sarma.

S100A2 induces epithelial-mesenchymal transition and metastasis in pancreatic cancer by coordinating transforming growth factor ß signaling in SMAD4-dependent manner.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive tumor and is associated with a poor prognosis. Treatment strategies for PDAC are largely ineffective primarily because of delay in its diagnosis and limited efficacy of systematic treatment. S100A2 is associated with the proliferation, migration, and differentiation of several tumors; however, its effects on PDAC and the associated molecular mechanisms remain to be explored. We studied the mechanisms underlying the effect of S100A2 on epithelial-mesenchymal transition (EMT) and metastasis in PDAC cells. We found that the level of S100A2 remarkably increased and was associated with poor PDAC prognosis. The overexpression of S100A2 in PANC-1 cells also induced EMT, in addition to increasing the invasion and migration of PDAC cells, whereas the knockdown of S100A2 markedly inhibited cell metastasis. Furthermore, S100A2 was found to enhance metastatic abilities in vivo. The overexpression of S100A2 increased SMAD4 expression, whereas the knockdown of S100A2 reduced SMAD4 expression. SMAD4 overexpression could effectively rescue the effects of S100A2 knockdown on EMT. S100A2 mechanistically activated the transforming growth factor (TGF)-ß/Smad2/3 signaling pathway, upregulated SMAD4 expression, induced EMT, and increased PANC-1 cell metastasis. In conclusion, the S100A2/SMAD4 axis modulates EMT to accelerate PDAC development. Our results supplement and enrich the understanding of the pathogenesis underlying PDAC and provide a new theoretical basis and strategy targeting S100A2 for the diagnosis and treatment of PDAC.

Phloretin-induced STAT3 inhibition suppresses pancreatic cancer growth and progression via enhancing Nrf2 activity.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a malignant pancreatic tumor charactered by a rapid progression and high lethal rate. Hyperactivation of STAT3 signaling exerts a vital effect on the growth and progression of PDAC. While dietary flavonoid phloretin has anti-inflammatory and antioxidant activities, it remains unclear whether phloretin has anti-tumor effects on PDAC. PURPOSE: The focus of the present study is to elucidate the effects of phloretin on PDAC and investigate its underlying molecular mechanisms. STUDY DESIGN AND METHODS: Effect of phloretin were assessed in the pancreatic cancer cells (PCCs) by colony formation assay, real-time cell analysis, flow cytometry, Immunofluorescence staining, and cell migration assay. The expressions of mRNA and protein were respectively analyzed by quantitative PCR and Western blotting. A xenograft model was used to appraise the antitumor efficacy of phloretin. RESULTS: Phloretin treatment significantly restrained cell viability and metastasis, induced DNA injury and ROS accumulation, and triggered mitochondrial-dependent apoptosis in PCCs. Mechanistically, phloretin exhibits anti-tumor potential via inactivating STAT3 signaling and enhancing Nrf2 activity. STAT3 overexpression and Nrf2 silencing partially relieved phloretin-induced inhibition on cell growth and metastasis in PCCs. Phloretin remarkably blocked pancreatic tumor growth and metastasis in vivo. CONCLUSIONS: Phloretin suppresses pancreatic cancer growth and progression through inhibition of STAT3 mediated by enhancing Nrf2 activity. Phloretin may serve as a promising therapeutic agent for PDAC.

STAT3 inhibition enhances gemcitabine sensitivity in pancreatic cancer by suppressing EMT, immune escape and inducing oxidative stress damage.

Pancreatic cancer (PC) is a highly-malignant tumor of the digestive system with a very poor prognosis and high mortality. Chemotherapy and PD-1/PD-L1 immune checkpoint blockade are important treatment strategies for advanced PC. However, chemotherapy resistance and poor therapeutic effect of immune checkpoint inhibitors is are the main clinical problems to be solved urgently at present. The effects of combined application of gemcitabine and STAT3 inhibition on the proliferation, apoptosis, migration, and invasion of PC cells (PCCs) were investigated. In addition, oxidative stress (OS), ferroptosis, immune escape, and the epithelial-mesenchymal transition (EMT) were evaluated. STAT3 inhibition with Stattic enhanced the inhibitory activity of gemcitabine on PCC proliferation by regulating the cell cycle. STAT3 inhibition enhanced mitochondrial-dependent apoptosis in gemcitabine-treated PCCs, but did not induce autophagy and ferroptosis. Further study showed that the anti-proliferative and pro-apoptotic effects may be associated with increased OS damage by inactivating Nrf2-HO-1 signaling, as well as DNA damage by inducing the imbalance between ATM andATR-Chk1 pathway. In addition, STAT3 inhibition strengthened gemcitabine-mediated suppression in PCC invasion and migration by antagonizing Smad2/3-dependent EMT. Moreover, the anti-tumorimmuneresponse of gemcitabine was upregulated by Stattic through reducing the expression of PD-L1 and CD47. Mechanistically, combined application of gemcitabine and Stattic suppressed the phosphorylation and nuclear expression of STAT3. Interestingly, the activities of AKT and ß-catenin signaling were also regulated, suggesting that drug combination has a broad-spectrum signal regulation effect. STAT3 inhibition enhanced the sensitivity of PCCs to the chemotherapy drug gemcitabine by suppressing EMT and immune escape and inducing OS damage.

Diagnostic model constructed by five EMT-related genes for renal fibrosis and reflecting the condition of immune-related cells.

Background: Renal fibrosis is a physiological and pathological characteristic of chronic kidney disease (CKD) to end-stage renal disease. Since renal biopsy is the gold standard for evaluating renal fibrosis, there is an urgent need for additional non-invasive diagnostic biomarkers. Methods: We used R package "limma" to screen out differently expressed genes (DEGs) based on Epithelial-mesenchymal transformation (EMT), and carried out the protein interaction network and GO, KEGG enrichment analysis of DEGs. Secondly, the least absolute shrinkage and selection operator (LASSO), random forest tree (RF), and support vector machine-recursive feature elimination (SVM-RFE) algorithms were used to identify candidate diagnostic genes. ROC curves were plotted to evaluate the clinical diagnostic value of these genes. In addition, mRNA expression levels of candidate diagnostic genes were analyzed in control samples and renal fibrosis samples. CIBERSORT algorithm was used to evaluate immune cells level. Additionally, gene set enrichment analysis (GSEA) and drug sensitivity were conducted. Results: After obtaining a total of 24 DEGs, we discovered that they were mostly involved in several immunological and inflammatory pathways, including NF-KappaB signaling, AGE-RAGE signaling, and TNF signaling. Five genes (COL4A2, CXCL1, TIMP1, VCAM1, and VEGFA) were subsequently identified as biomarkers for renal fibrosis through machine learning, and their expression levels were confirmed by validation cohort data sets and in vitro RT-qPCR experiment. The AUC values of these five genes demonstrated significant clinical diagnostic value in both the training and validation sets. After that, CIBERSORT analysis showed that these biomarkers were strongly associated with immune cell content in renal fibrosis patients. GSEA also identifies the potential roles of these diagnostic genes. Additionally, diagnostic candidate genes were found to be closely related to drug sensitivity. Finally, a nomogram for diagnosing renal fibrosis was developed. Conclusion: COL4A2, CXCL1, TIMP1, VCAM1, and VEGFA are promising diagnostic biomarkers of tissue and serum for renal fibrosis.

Trans-cinnamaldehyde attenuates renal ischemia/reperfusion injury through suppressing inflammation via JNK/p38 MAPK signaling pathway.

Inflammation is the major contributor to the mechanisms of acute kidney injury due to renal ischemia-reperfusion injury (IRI). Trans-cinnamaldehyde (TCA) is a main bioactive component extracted from the bark of cinnamon and has been proved to have good anti-inflammatory properties. The current study was to demonstrate the effect of TCA on renal IRI and explore its specific mechanism. C57BL/6J mice were injected prophylactically intraperitoneally for TCA 3 days, and IRI for 24 h. In parallel, Human Kidney-2 (HK-2) cells were prophylactically treated with TCA, and then exposed to oxygen glucose deprivation/reperfusion (OGD/R) and cobalt chloride (CoCl2). TCA was found to significantly attenuate renal pathological changes and renal dysfunction, and inhibit gene and protein expression of kidney injury molecule-1 (Kim-1) and neutrophil gelatinase-associated lipocalin (NGAL). Furthermore, TCA significantly suppressed the expression of TNF-α, IL-6, IL-1ß, COX-2, iNOS, and MCP-1. Mechanistically, the activation of the JNK/p38 MAPK signaling pathway was inhibited by TCA in renal IRI as well as in OGD/R and CoCl2-stimulated cells. However, following pretreatment with anisomycin before OGD/R treatment, we found that the activation of the JNK/p38 MAPK signaling pathway was significantly enhanced, and concomitant abrogation of the TCA inhibitory effect on the JNK/p38 MAPK signaling pathway, which was followed by a worsening of cell injury that was characterized by an increased number of cell necrosis and an increase in the expression of Kim-1, NGAL as well as proinflammatory factors (IL-6, IL-1ß, iNOS). In summary, TCA inhibited renal inflammation via the JNK/p38 MAPK signaling pathway and attenuated renal IRI.

Hydrogen regulates mitochondrial quality to protect glial cells and alleviates sepsis-associated encephalopathy by Nrf2/YY1 complex promoting HO-1 expression.

BACKGROUND: Sepsis-associated encephalopathy (SAE) is a complication of the central nervous system in patients with sepsis. Currently, no effective treatment for sepsis is available. Hydrogen plays a protective role in different diseases; however, the detailed mechanism of hydrogen-treated disease remains unclear. The purpose of this study was to investigate the effect of hydrogen on SAE in vitro and in vivo and the mechanism of hydrogen in mitochondrial dynamics and its function in astrocytes and microglia stimulated by lipopolysaccharides (LPSs). METHODS: Animal models of SAE were generated by cecal ligation and puncture, and the SAE model was established by in vitro LPS stimulation. MTT, lactate dehydrogenase (LDH), reactive oxygen species (ROS), heme oxygenase-1 (HO-1) activity, mitochondrial membrane potential (MMP), and cell apoptosis assays were used to determine the effect of hydrogen on astrocytes and microglia stimulated by LPSs. The relationships between nuclear factor erythroid 2-related factor 2 (Nrf2), YY1, and HO-1 were examined by chromatin immunoprecipitation and co-immunoprecipitation. Mitochondrial homeostasis-related proteins in LPS-stimulated glial cells and brain tissues of SAE mice were detected by western blotting. The effects of hydrogen treatment in the SAE mouse model were investigated using Morris water maze and Y-maze analyses. RESULTS: After performing experiments with different concentrations of LPSs in vitro, we selected 1000 ng/ml for subsequent experiments. Hydrogen attenuated the increase in ROS, LDH, and apoptosis and promoted decreases in cell activity and MMP, further promoting an increase in HO-1 expression induced by LPSs in astrocytes and microglia. Moreover, hydrogen further promoted the expression of Nrf2, HO-1, PGC-1α, TFAM, PARKIN, and PINK1, inhibited LPS-induced OPA1 and MFN2 expression in astrocytes and microglia, and downregulated the expression of DRP1 after LPS induction. Intriguingly, hydrogen treatment enhanced the binding between Nrf2 and YY1. However, silencing Nrf2 or YY1 abolished the protective effects of hydrogen on cell activity, LDH, ROS, and MMP; apoptosis; and regulation of Nrf2, HO-1, PGC-1α, TFAM, OPA1, DRP1, MFN2, PARKIN, and PINK1 in microglia. Finally, hydrogen treatment improved the results of behavioral detection, apoptosis, Nrf2, HO-1, PGC-1α, TFAM, OPA1, DRP1, MFN2, PARKIN, PINK1, and cytokines in SAE in vivo. CONCLUSIONS: Hydrogen improved cell injury and mitochondrial quality, which were associated with HO-1 expression promoted by the Nrf2/YY1 complex in vitro. Thus, hydrogen treatment may represent a novel therapeutic method for treating SAE.

Corrigendum: CircAFF1 aggravates vascular endothelial cell dysfunction mediated by miR-516b/SAV1/YAP1 axis.

[This corrects the article DOI: 10.3389/fphys.2020.00899.].

Myxoinflammatory Fibroblastic Sarcoma of the Parotid Gland: First Case Report and Literature Review.

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare, low-grade malignant soft tissue tumor. Most of the previously reported cases about this tumor were diagnosed within the soft tissues. Here, we report a unique case of MIFS of the right parotid gland in a 39-year-old Chinese male. The tumor primarily consisted of an inflammatory area and a mucus-like area in a migratory distribution. A number of lymphocytes, neutrophils, viral-like cells with large nucleoli, and eosinophilic cytoplasm or Reed-Sternberg-like cells, as well as spindle cells and epithelial-like aberrant cells, were observed within the tumor. They were found to express Vimentin and CD10 protein and no other specific immunohistochemical markers. The various cytomorphology and immunohistochemical features of this tumor were highly consistent with MIFS found in other sites. Therefore, several leading pathologists ultimately confirmed the final diagnosis of MIFS in the right parotid gland after repeated deliberation. To our knowledge, this is the first case of MIFS occurring in the parotid gland. Thus, our study provides a novel basis for identifying the biological behavior of the tumor in MIFS and also allows us to better understand the pathology of this rare tumor.

Inhibition of STAT3Y705 phosphorylation by Stattic suppresses proliferation and induces mitochondrial-dependent apoptosis in pancreatic cancer cells.

Patients with pancreatic cancer (PC) show dismal prognosis and high mortality. The development of PC is associated with the overactivation of STAT3. Here, we have determined that the non-peptide small molecule Stattic inhibits PC development by targeting STAT3. In vitro, Stattic treatment time- and dose-dependently inhibited proliferation of pancreatic cancer cells (PCCs) by reducing c-Myc expression and enhancing p53 activity. Consequently, p-Rb, cyclin D1, Chk1, and p21 (cell cycle proteins) were downregulated, and PCCs were arrested at the G1 phase, which was also confirmed by decreased Ki67 expression and unaltered PCNA expression. In addition, Stattic-induced mitochondrial-dependent apoptosis by elevating cleaved caspase-3, and Bax, cytochrome C levels, while reducing expression of Bcl-2, which may be regulated by reduced survivin expression. Further studies showed that Stattic exerts its anti-tumor effect via inhibition of STAT3Y705 phosphorylation and nuclear localization in PCCs. In a nude mouse tumorigenesis model, Stattic inhibited PC growth by antagonizing STAT3Y705 phosphorylation. Interleukin-6 used as a molecule agonist to activate STAT3, as well as overexpression of STAT3, could partially reverse Stattic-mediated anti-proliferation and pro-apoptotic effects of PCCs. Thus, these findings indicate that inhibition of STAT3Y705 phosphorylation by Stattic suppresses PCC proliferation and promotes mitochondrial-mediated apoptosis.

The anthelmintic drug niclosamide induces GSK-ß-mediated ß-catenin degradation to potentiate gemcitabine activity, reduce immune evasion ability and suppress pancreatic cancer progression.

Niclosamide, a cell-permeable salicylanilide, was approved by the Food and Drug Administration for its anthelmintic efficiency. A growing body of evidence in recent years suggests that niclosamide exhibits potential tumor-suppressive activity. However, the role and molecular mechanism of niclosamide in pancreatic cancer remain unclear. In this study, niclosamide inhibited proliferation of pancreatic cancer cells (PCCs), induced apoptosis via the mitochondrial-mediated pathway, and suppressed cell migration and invasion by antagonizing epithelial-to-mesenchymal transition. Also, niclosamide inhibited tumor growth and metastasis in pancreatic cancer xenograft mouse models. Mechanistically, niclosamide exerted these therapeutic effects via targeting ß-catenin. Niclosamide did not reduce ß-catenin mRNA expression in PCCs, but significantly downregulated its protein level. Moreover, niclosamide induced ß-catenin phosphorylation and protein degradation. Interestingly, niclosamide also induced GSK-3ß phosphorylation, which is involved in the ubiquitination degradation of ß-catenin. Pharmacological activation of ß-catenin by methyl vanillate and ß-catenin overexpression abolished the inhibitory effects of niclosamide. Furthermore, niclosamide potentiated the antitumor effect of the chemotherapy drug gemcitabine and reduced the ability of cancer immune evasion by downregulating the expression levels of PD-L1, which is involved in T cell immunity. Thus, our study indicated that niclosamide induces GSK-ß-mediated ß-catenin degradation to potentiate gemcitabine activity, reduce immune evasion ability, and suppress pancreatic cancer progression. Niclosamide may be a potential therapeutic candidate for pancreatic cancer.

Immunotherapeutic Potential of T Memory Stem Cells.

Memory T cells include T memory stem cells (TSCM) and central memory T cells (TCM). Compared with effector memory T cells (TEM) and effector T cells (TEFF), they have better durability and anti-tumor immunity. Recent studies have shown that although TSCM has excellent self-renewal ability and versatility, if it is often exposed to antigens and inflammatory signals, TSCM will behave as a variety of inhibitory receptors such as PD-1, TIM-3 and LAG-3 expression, and metabolic changes from oxidative phosphorylation to glycolysis. These changes can lead to the exhaustion of T cells. Cumulative evidence in animal experiments shows that it is the least differentiated cell in the memory T lymphocyte system and is a central participant in many physiological and pathological processes in humans. It has a good clinical application prospect, so it is more and more important to study the factors affecting the formation of TSCM. This article summarizes and prospects the phenotypic and functional characteristics of TSCM, the regulation mechanism of formation, and its application in treatment of clinical diseases.

Pyroptosis, a New Breakthrough in Cancer Treatment.

The way of cell death can be roughly divided into two categories: cell necrosis and PCD(programmed cell death). Pyroptosis is a kind of PCD, its occurrence depends on the gasdermin protein family and it will produce inflammatory response. With constant research in recent years, more and more evidences show that pyroptosis is closely related to the occurrence and development of tumors. The treatment of tumors is a big problem worldwide. We focus on whether we can discover new potential tumor markers and new therapeutic targets from the mechanism. If we can understand the mechanism of pyroptosis and clear the relationship between pyroptosis and the development of tumors, this may provide a new reference for clinical cancer treatment.

circAFF1 Aggravates Vascular Endothelial Cell Dysfunction Mediated by miR-516b/SAV1/YAP1 Axis.

Pathological vascular endothelial damage caused by hypoxia is the basis of many vascular-related diseases. However, the role of circular RNA in hypoxic vascular injury is still poorly understood. Here, we found that hypoxia induced AFF1 circular RNA (circAFF1) can activate the SAV1/YAP1 and lead to the dysfunction of vascular endothelial cells. In HUV-EC-C and HBEC-5i cells, circAFF1 was upregulated under CoCl2 induced hypoxic conditions. The abnormal expression of circAFF1 inhibited the proliferation, tube formation, migration of vascular endothelial cells. The effect of circAFF1 is achieved by the adsorption of miR-516b to release SAV1, which in turn causes the phosphorylation of YAP1. Moreover, we found that the upregulation of circAFF1 in 235 Patients with subarachnoid hemorrhage. Taken together, we clarify the role of circAFF1/miR-516b/SAV1/YAP1 axis in vascular endothelial dysfunction and its potential early diagnostic value of disease caused by hypoxia injury in blood vessels.