Discovery of cinnamylaldehyde-derived mono-carbonyl curcumin analogs as anti-gastric cancer agents via suppression of STAT3 and AKT pathway

The structural modification of curcumin has always been a hotspot in drug development. In this paper, a class of cinnamylaldehyde-derived mono-carbonyl curcumin analogs (MCAs) with 7-carbon-links were designed and synthesized and their anticancer properties were evaluated. Through screening anti-gastric cancer activity of these compounds, H1 exhibited the strongest cytotoxic activity by inhibiting cell viability and colony formation, inducing cell cycle G2/M phase arrest in vitro (SGC-7901 and AGS gastric cancer cells). Moreover, the SGC-7901 subcutaneous tumor-bearing mice studies revealed that H1 significantly inhibited the tumor growth of gastric cancer. We explored the possible potential targets of H1 through network pharmacology. Mechanistically, our results demonstrated that H1 showed potential anti-gastric cancer activity through suppression of the STAT3 and AKT signaling pathway in vitro and in vivo, which was validated by molecular docking. Overall, our results indicate the potential of H1 as a potent chemotherapeutic drug against gastric cancer.

Inhibiting IL11RA to mitigate hepatic metastasis in skin cutaneous melanoma: Comprehensive insights from in vitro and in vivo investigations

OBJECTIVE

This study aimed to investigate the role of Interleukin-11 receptor alpha (IL11RA) in skin cutaneous melanoma (SKCM) metastasis to the liver.

METHODS

Human SKCM cell lines (A375, A375-MA2, SK-MEL-28, RPMI-7951) and primary dermal fibroblasts (HDFa) were utilized to assess IL11RA expression. IL11RA siRNA was transfected into RPMI-7951 and A375-MA2 cells for Wound healing and Transwell invasion assays. Il11ra knockout (KO) mice and wild-type (WT) mice were injected with B16-F10 cells into the spleen to evaluate hepatic melanoma metastasis. Correlation between IL11RA and MMP family genes was explored using online databases, including LinkedOmics, TIMER (Tumor Immune Estimation Resource), and GEPIA (Gene Expression Profiling Interactive Analysis). RT-qPCR and Western blotting were performed for expression analysis of Mmp2 and Mmp9 in liver tissues of mice. The impact of IL11RA on the STAT3 pathway was investigated in vitro and in vivo.

RESULTS

Elevated expression of IL11RA was observed in SKCM cell lines compared to normal cells. IL11RA downregulation significantly inhibited migratory and invasive capabilities of A375-MA2 and RPMI-7951 in vitro. Il11ra gene knockout in mice demonstrated a substantial reduction in hepatic melanoma metastasis. Correlation analyses revealed associations between IL11RA and MMP2/MMP8. Il11ra gene knockout significantly decreased Mmp2 expression while increasing Mmp8 in liver tissues. IL11RA correlated positively with STAT3, and its inhibition led to a suppressed STAT3 pathway in SKCM cells and mouse liver tissue.

CONCLUSION

IL11RA plays a crucial role in SKCM metastasis, affecting migratory and invasive abilities. Targeting IL11RA may offer a promising avenue for therapeutic interventions in cutaneous melanoma progression.

Malat1 regulates PMN-MDSC expansion and immunosuppression through p-STAT3 ubiquitination in sepsis

Myeloid-derived suppressor cells (MDSCs) expand during sepsis and contribute to the development of persistent inflammation-immunosuppression-catabolism syndrome. However, the underlying mechanism remains unclear. Exploring the mechanisms of MDSCs generation may provide therapeutic targets for improving immune status in sepsis. Here, a sepsis mouse model is established by cecal ligation and perforation. Bone marrow cells at different sepsis time points are harvested to detect the proportion of MDSCs and search for differentially expressed genes by RNA-sequence. In lethal models of sepsis, polymorphonuclear-MDSCs (PMN-MDSCs) decrease in early but increase and become activated in late sepsis, which is contrary to the expression of metastasis-associated lung adenocarcinoma transcript 1 (Malat1). In vivo, Malat1 inhibitor significantly increases the mortality in mice with late sepsis. And in vitro, Malat1 down-regulation increases the proportion of PMN-MDSCs and enhanced its immunosuppressive ability. Mechanistically, Malat1 limits the differentiation of PMN-MDSCs by accelerating the degradation of phosphorylated STAT3. Furthermore, Stattic, an inhibitor of STAT3 phosphorylation, improves the survival of septic mice by inhibiting PMN-MDSCs. Overall, the study identifies a novel insight into the mechanism of sepsis-induced MDSCs and provides more evidence for targeting MDSCs in the treatment of sepsis.

Down-Regulation of INSR Restores Th17/Treg Immune Balance and Alleviates Airway Hyperviscosity in Asthmatic Mice via Inactivation of STAT3 Pathway

BACKGROUND

Allergic asthma (AA) is a prevalent chronic airway inflammation disease. In this study, this study aims to investigate the biological functions and potential regulatory mechanisms of the insulin receptor (INSR) in the progression of AA.

METHODS

BALB/c mice (n = 48) were randomly divided into the following groups: control group, AA group, AA+Lentivirus (Lv)-vector short hairpin RNA (shRNA) group, AA+Lv-vector group, AA+Lv-INSR shRNA group, and AA+Lv-INSR group. The pulmonary index was calculated. mRNA and protein expression levels of INSR, signal transducer and activator of transcription 3 (STAT3), Janus kinase 2 (JAK2), phosphorylated-STAT3 (p-STAT3), phosphorylated-JAK2 (p-JAK2), alpha-smooth muscle actin (α-SMA), febrile neutropenia (FN), mucin 5AC (MUC5AC), and mucin 5B (MUC5B) were examined using reverse-transcription quantitative PCR (RT-qPCR) and western blot assays. Positive expressions of INSR, retinoic acid-related orphan receptor gamma-t (RORγt), and forkhead box protein P3 (Foxp3) were quantified by immunohistochemistry. Fluorescence intensities of α-SMA and FN were detected by immunofluorescence. Pathological morphology was observed through hematoxylin-eosin (H&E) staining, Masson staining, and Periodic Acid-Schiff (PAS) staining. Contents of immunoglobulin E (IgE), interleukin-6 (IL-6), eotaxin, interleukin-4 (IL-4), interleukin-13 (IL-13), interferon-γ (IFN-γ), interleukin-17 (IL-17), and interleukin-10 (IL-10) were quantified using enzyme-linked immunosorbent assay (ELISA). The percentage of T helper 17 (Th17) and regulatory T (Treg) cells was determined through flow cytometry.

RESULTS

Compared to the control group, expression levels of INSR, p-STAT3, p-JAK2, α-SMA, FN, MUC5AC, MUC5B, RORγt, and Foxp3, as well as IgE, IL-6, eotaxin, IL-4, IL-13, and IL-17 contents, pulmonary index, glycogen-positive area (%), and Th17 cell percentage significantly increased (p < 0.05). Additionally, pulmonary histopathological deterioration and collagen deposition were aggravated, while Treg cell percentage and IFN-γ and IL-10 contents remarkably decreased (p < 0.05). The overexpression of INSR further exacerbated the progression of allergic asthma, but the down-regulation of INSR reversed the trends of the above indicators.

CONCLUSIONS

The down-regulation of INSR alleviates airway hyperviscosity, inflammatory infiltration, and airway remodeling, restoring Th17/Treg immune balance in AA mice by inactivating the STAT3 pathway.

Increased serum α-tocopherol acetate mediated by gut microbiota ameliorates alveolar bone loss through the STAT3 signalling pathway in diabetic periodontitis

AIM

To evaluate whether and how gut microbiota-meditated metabolites regulate alveolar bone homeostasis in diabetic periodontitis (DP).

MATERIALS AND METHODS

Lactobacillus casei (L. casei) was employed as a positive modulator of gut microbiota in DP mice. The destruction of alveolar bone was evaluated. Untargeted metabolomics was conducted to screen out the pivotal metabolites. A co-housing experiment was conducted to determine the connection between the gut microbiota and alpha-tocopherol acetate (α-TA). α-TA was applied to DP mice to investigate its effect against alveolar bone loss. Human periodontal ligament cells (hPDLCs) and human gingival fibroblasts (HGFs) were extracted for the in vitro experiment. Transcriptomic analysis and immunohistochemistry were performed to detect the major affected signalling pathways.

RESULTS

Positive regulation of the gut microbiota significantly attenuated alveolar bone loss and increased the serum α-TA level. The alteration in gut microbiota composition could affect the serum α-T (the hydrolysates of α-TA) level. α-TA could alleviate alveolar bone destruction in DP mice and α-T exert beneficial effects on hPDLCs and HGFs. Mechanistically, the STAT3 signalling pathway was the pivotal pathway involved in the protective role of α-TA.

CONCLUSIONS

The gut microbiota-α-TA-STAT3 axis plays an important role in the regulation of diabetic alveolar bone homeostasis.

Knock-down of IGFBP2 ameliorates lung fibrosis and inflammation in rats with severe pneumonia through STAT3 pathway

OBJECTIVE

To observe the mechanism of IGFBP2 knock-down in improving lung fibrosis and inflammation through STAT3 pathway in rats with severe pneumonia.

MATERIALS AND METHODS

First, SP rat model was established. Then rats were divided into the Control group, the SP group, the SP + Lv-vector shRNA group, the SP + Lv-IGFBP2 shRNA group, the SP + Lv-vector group, and the SP + Lv-IGFBP2 group. The mRNA and protein levels of IGFBP2, NOS, CD206 and Arg 1 were detected by RT-qPCR and Western blot. IHC was used to check the positive expression of IGFBP2 and MCP1. A fully automated blood gas analyzer was used to detected PaCO2, CO2 content, PaO2 and SaO2. HE and Masson staining were performed to observe the lung tissue injury and collagen deposition of rats in each group. ELISA assays were used to calculate the levels of inflammatory factors IL-1β, IL-6, TNF-α, IL-4, and IL-10. Flow cytometry was conducted to acquire the ratio of M1-type AMs and M2-type AMs.

RESULTS

Compared with the Control group, IGFBP2, iNOS, CD206, and Arg1 mRNA and protein expression levels, IGFBP2 and MCP1 positive expressions, PaCO2, p-STAT3/STAT3, p-JAK2/JAK2, IL-1β, IL-6, and TNF-α levels, the number of AMs and neutrophils, the proportion of M1 type AMs and the expressions of α-SMA, Collagen-I, Collagen III, and Fibronectin were significantly increased in SP rats (p < 0.05), while PaCO2, CO2, and SaO2, IL-4 and IL-10 levels, and the proportion of M2 type AMs decreased (p < 0.05). However, the knockdown of IGFBP2 reversed the above index trends.

CONCLUSION

Knock-down of IGFBP2 ameliorated lung injury in SP rats, inhibited inflammation and pulmonary fibrosis, and promoted M2-type transformation of AMs by activating the STAT3 pathway.

A novel LncRNA SPIRE1/miR-181a-5p/PRLR axis in mandibular bone marrow-derived mesenchymal stem cells regulates the Th17/Treg immune balance through the JAK/STAT3 pathway in periodontitis

Periodontitis is a microbial-related chronic inflammatory disease associated with imbalanced differentiation of Th17 cells and Treg cells. Bone marrow-derived mesenchymal stem cells (BM-MSCs) possess wide immunoregulatory properties. Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) contribute to the immunomodulation in the pathological mechanisms of inflammatory diseases. However, critical lncRNAs/miRNAs involved in immunomodulation of mandibular BM-MSCs largely remain to be identified. Here, we explored the molecular mechanisms behind the defective immunomodulatory ability of mandibular BM-MSCs under the periodontitis settings. We found that mandibular BM-MSCs from P. gingivalis-induced periodontitis mice had significantly reduced expression of LncRNA SPIRE1 than that from normal control mice. LncRNA SPIRE1 knockdown in normal BM-MSCs caused Th17/Treg cell differentiation imbalance during the coculturing of BM-MSCs and CD4 T cells. In addition, LncRNA SPIRE1 was identified as a competitive endogenous RNA that sponges miR-181a-5p in BM-MSCs. Moreover, miR-181a-5p inhibition attenuated the impact of LncRNA SPIRE1 knockdown on the ability of BM-MSCs in modulating Th17/Treg balance. Prolactin receptor (PRLR) was validated as a downstream target of miR-181a-5p. Notably, targeted knockdown of LncRNA SPIRE1 or PRLR or transfection of miR-181a-5p mimics activated the JAK/STAT3 signaling in normal BM-MSCs, while treatment with STAT3 inhibitor C188-9 restored the immunomodulatory properties of periodontitis-associated BM-MSCs. Furthermore, BM-MSCs with miR-181a-5p inhibition or PRLR-overexpression showed enhanced in vivo immunosuppressive properties in the periodontitis mouse model. Our results indicate that the JAK/STAT3 pathway is involved in the immunoregulation of BM-MSCs, and provide critical insights into the development of novel targeted therapies against periodontitis.

E2F3 accelerates the stemness of colon cancer cells by activating the STAT3 pathway

Introduction

Colon cancer is one of the most prevalent malignancies and causes of cancer-related deaths worldwide. Thus, further research is required to explicate the latent molecular mechanisms and look for novel biomarkers. E2F3 has been confirmed to be an oncogene in a variety of cancers. However, the particular regulation of E2F3 in colon cancer needs further investigation.

Methods

The self-renewal ability was detected through a sphere formation assay. The tumorigenic ability was measured through nude mice in vivo assay. The protein expression of genes was examined through a Western blot. The expression of E2F3 in tumor tissues was detected through an IHC assay. The resistance to cisplatin was assessed through the CCK-8 assay. The cell migration and invasion abilities were measured after upregulating or suppressing E2F3 through the Transwell assay.

Results

Results uncovered that E2F3 was upregulated in spheroid cells. In addition, E2F3 facilitates stemness in colon cancer. Moreover, E2F3 facilitated colon cancer cell migration and invasion. Finally, it was revealed that E2F3 affected the STAT3 pathway to modulate stemness in colon cancer. E2F3 served as a promoter regulator in colon cancer, aggravating tumorigenesis and stemness in colon cancer progression through the STAT3 pathway.

Conclusion

E2F3 may be a useful biomarker for anticancer treatment in colon cancer.

Acute/chronic exposure to bisphenol A induced immunotoxicity in zebrafish and its potential association with pancreatic cancer risk

Previous studies have confirmed that bisphenol A (BPA) induced immune toxicity and affected diseases, however, the underlying mechanism remains unknown. In the present study, zebrafish was employed as the model to assess the immunotoxicity and the potential disease risk of BPA exposure. Upon BPA exposure, a series of abnormalities were found, which included the increased oxidative stress, damaged innate and adaptive immune functions and the elevated insulin and blood glucose levels. According to the target prediction and RNA sequencing data of BPA, the differential expression genes were found enriched in immune- and pancreatic cancer-related pathway and process, and the potential role of stat3 in the regulation of these processes was revealed. The key immune- and pancreatic cancer-related genes were selected for further confirmation by RT-qPCR. Based on the changes in the expression levels of these genes, our hypothesis that BPA induced the occurrence of pancreatic cancer by modulating immune responses was further evidenced. Deeper mechanism was further disclosed by molecular dock simulation and survival analysis of key genes, proving that BPA stably bound to STAT3 and IL10 and STAT3 may serve as the target of BPA-inducing pancreatic cancer. These results are of great significance in deepening the molecular mechanism of immunotoxicity induced by BPA and our understanding of the risk assessment of contaminants.

Silybum marianum: An Overview of its Phytochemistry and Pharmacological Activities with Emphasis on Potential Anticancer Properties

Silybum marianum (SM) belongs to the family Asteraceae, which holds therapeutic significance in medicinal chemistry. Phytochemistry analysis revealed an abundance of active constituents, particularly silymarin, composed of polyphenols and flavonolignans. Silymarin is majorly found in leaves, seeds, and fruits and is comprised of seven flavonolignans. Silymarin derivatives, specifically silybin, were reported for their medicinal properties. This review summarizes the studies conducted to evaluate SM's pharmacological properties and proposed mechanisms. SM exhibited anticancer properties due to being capable of modifying the induction of apoptosis, inhibiting the STAT3 pathway, decreasing the transcription of various growth factors, impeding the growth of 4T1 cells and inducing cell cycle arrest in various types of cancers, i.e., skin cancer, liver cancer, breast cancer, ovarian cancer etc. Silymarin and its derivatives protect the liver and ameliorate various immune-mediated and autoimmune hepatic diseases. Moreover, antimicrobial, antidiabetic, cardioprotective, nephroprotective, and neuroprotective activities were also reported. Based on testified in vitro and in vivo studies, SM can serve as an alternative to cure various pathological ailments.

NINJ1 triggers extravillous trophoblast cell dysfunction through blocking the STAT3 signaling pathway

BACKGROUND

Trophoblasts are the most important parts of the placenta in early pregnancy. Trophoblast cell dysfunction can induce embryo implantation insufficiency, thereby resulting in multiple diseases, including recurrent spontaneous abortion (RSA). A previous study indicates higher nerve injury-induced protein 1 (NINJ1) RNA levels in the villi tissues of RSA patients.

OBJECTIVE

This study aimed to investigate the effect of NINJ1 on trophoblast behaviors and pregnancy loss.

METHODS

Fresh villi tissues were obtained from with RSA patients and patients with artificial selective abortion for personal reasons, and NINJ1 expression in these tissues was detected. Extravillous trophoblast cell line HTR-8/SVneo was transfected with small-interfering RNA targeting NINJ1 or NINJ1 overexpression vector to perform loss-/gain-of-function experiments. Spontaneous abortion (SA) was induced by mating CBA/J females with DBA/2 males and the pregnant females were intraperitoneally injected with adenovirus vector carrying NINJ1 short hairpin RNA.

RESULTS

NINJ1 mRNA and protein levels were higher in the villi tissues of RSA patients than those of artificial selective abortion patients. NINJ1 knockdown promoted trophoblast cell proliferation, migration and invasion but inhibited cell apoptosis. Moreover, conditioned medium from NINJ1-depleted trophoblasts promoted the angiogenesis of human umbilical vein endothelial cells. NINJ1 knockdown also promoted activation of the signal transducer and activator of transcription 3 (STAT3) signaling pathway in trophoblasts, and STAT3 inhibitor reversed NINJ1 knockdown-induced effects on trophoblast behaviors. Furthermore, pregnancy loss was attenuated by NINJ1 inhibition.

CONCLUSION

NINJ1 contributes to the development of SA and triggers trophoblast cell dysfunction through inhibiting the STAT3 pathway.

The potential of B7-H6 as a therapeutic target in cancer immunotherapy

Immune checkpoints are vital molecules that regulate T-cell function by activation or inhibition. Among the immune checkpoint molecules, the B7-family proteins are significantly involved in the immune escape of tumor cells. By binding to inhibitory receptors, they can suppress T-cell-mediated immunity. B7-family proteins are found at various stages of tumor microenvironment formation and promote tumorigenesis and tumor progression. B7-H6 (encoded by gene NCR3LG1) is a prominent member of the family. It has unique immunogenic properties and is involved in natural killer (NK) cell immunosurveillance by binding to the NKp30 receptor. High B7-H6 expression in certain tumor types and shortage of or low expression in healthy cells - except in cases of inflammatory or microbial stimulation - have made the protein an attractive target of research activities in recent years. The avoidance of NK-mediated B7-H6 detection is a mechanism through which tumor cells escape immune surveillance. The stimulation of tumorigenesis occurs by suppressing caspase cascade initiation and anti-apoptosis activity stimulation via the STAT3 pathway. The B7-H6-NKp30 complex on the tumor membrane activates the NK cells and releases both tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ). B7-H6 is highly expressed in a wide range of tumor cells, including glioma, hematologic malignant tumors, and breast cancer cells. Clinical examination of cancer patients indicated that the expression of B7-H6 is related to distant metastasis status and permits postoperative prognosis. Because of its unique properties, B7-H6 has a high potential be utilized as a biological marker for cancer diagnosis and prognosis, as well as a target for novel treatment options.

[Effect of fire needling on imiquimod induced psoriasis-like lesion and STAT3 pathway in mice]

OBJECTIVE

To observe the effect of fire needling on psoriasis-like lesion and the signal transducer and activator of transcription 3 (STAT3) pathway in mice and compare the therapeutic effect between different interventions of fire needling therapy (surrounding technique of fire needling, fire needling at "Dazhui" [GV 14] and "Zusanli" [ST 36]).

METHODS

Thirty male BALB/c mice were randomized into a blank group, a model group, a dexamthasone group, a surrounding technique group and an acupoint group, 6 mice in each one. Except the blank group, the mice in the rest groups were established as psoriasis-like lesion model by topical application with imiquimod cream, once daily, consecutively for 8 days. From day 4 to day 8, in the dexamthasone group, gastric infusion with 0.2 mL dexamthasone was administered, once daily. On day 4, 6 and 8, in the surrounding technique group, fire needling was exerted around the skin lesion; and fire needling was applied to "Dazhui" (GV 14) and "Zusanli" (ST 36) in the acupoint group, once a day. The changes in skin lesion on the dorsal parts of mice were observed in each group to score the psoriasis area and severity index (PASI). Using HE staining, the dermal morphological changes and epidermal thickness were observed in the mice of each group. The positive expression of proliferating cell-associated antigen Ki-67 was determined by immunofluorescence. Immunohistochemistry method was used to determine the expressions of , and T cells of skin tissue in each group. Using real-time PCR, the expressions of interleukin (IL)-17, IL-22, tumor necrosis factor α(TNF-α) mRNA were determined. Western blot method was adopted to determine the protein expressions of STAT3 and p-STAT3 in skin tissue in each group.

RESULTS

Compared with the blank group, the scores of each item and the total scores of PASI, as well as the epidermal thickness were all increased in the mice of the model group (P<0.01). Except for the erythema scores of the dexamethasone group and the surrounding technique group, the scores of each item and the total scores of PASI, as well as the epidermal thickness were all decreased in each intervention group as compared with the model group (P<0.01). The infiltration scores and the total scores in the dexamethasone group and the acupoint group were lower than those in the surrounding technique group respectively (P<0.01, P<0.05). In comparison with the blank group, Ki-67 positive cell numbers and the numbers of , and T cells in skin tissue were increased in the mice of the model group (P<0.01). Ki-67 positive cell numbers and the numbers of , and T cells were reduced in each intervention group as compared with the model group (P<0.01), and the numbers of and T cells in the acupoint group were less than the surrounding technique group (P<0.01). Compared with the blank group, the mRNA expressions of IL-17, IL-22 and TNF-α and the ratio of p-STAT3 to STAT3 were all increased in the model group (P<0.01). The mRNA expressions of IL-17, IL-22 and TNF-α and the ratio of p-STAT3 to STAT3 were all decreased in each intervention group as compared with the model group (P<0.01, P<0.05). The mRNA expressions of IL-17, IL-22 and TNF-α in the acupoint group, as well as mRNA expression of IL-17 in the surrounding technique group were all lower than the dexamethasone group (P<0.01), while, the mRNA expression of IL-22 in the acupoint group was lower than the surrounding technique group (P<0.01).

CONCLUSION

Fire needling therapy improves skin lesion severity in imiquimod induced psoriasis-like lesion of the mice, which is probably related to the inhibition of STAT3 pathway activation and the decrease of Th17 inflammatory factors expression. The systemic regulation of fire needling at "Dazhui" (GV 14) and "Zusanli" (ST 36) is superior to the local treatment.

lncRNA PRADX is a Mesenchymal Glioblastoma Biomarker for Cellular Metabolism Targeted Therapy

Glioblastoma (GBM) is the most common and lethal type of primary malignant central nervous system (CNS) tumor with an extremely poor prognosis, and the mesenchymal subtype of GBM has the worst prognosis. Here, we found that lncRNA PRADX was overexpressed in the mesenchymal GBM and was transcriptionally regulated by RUNX1-CBFβ complex, overexpressed PRADX suppressed BLCAP expression via interacting with EZH2 and catalyzing trimethylation of lysine 27 on histone H3 (H3K27me3). Moreover, we showed that BLCAP interacted with STAT3 and reduced STAT3 phosphorylation, overexpressed PRADX activated STAT3 phosphorylation, and promoted ACSL1 expression via suppressing BLCAP expression, accelerating tumor metabolism. Finally, we determined that combined of ACSL1 and CPT1 inhibitors could reverse the accelerated cellular metabolism and tumor growth induced by PRADX overexpression in vivo and in vitro. Collectively, PRADX/PRC2 complex activated the STAT3 pathway and energy metabolism in relation to mesenchymal GBM progression. Furthermore, our findings provided a novel therapeutic strategy targeting the energy metabolism activity of GBM.

The anti-tumor effect of OP-B on ovarian cancer in vitro and in vivo, and its mechanism: An investigation using network pharmacology-based analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Maidong (Liliaceae) is used as a yin-nourishing medication for the treatment of cardiovascular disease, inflammation, and assistant cancer chemotherapy in the clinic. Ophiopogonin B (OP-B), a major saponin extracted from Maidong, is reported to have potential antitumor activities against various human cancers. However, the effects of OP-B on human ovarian cancer (OC) and the potential mechanisms of action are yet elusive.

AIM OF THE STUDY

In this study, we aimed to explore the potential molecular mechanisms of OP-B in the treatment of OC using network pharmacology. In vivo and in vitro experiments were conducted to further verify the therapeutic effects of OP-B on OC.

MATERIALS AND METHODS

To investigate the functions of OP-B against OC holistically, the related targets of OP-B and OC were each predicted based on four public databases. Subsequently, the identified PPI network was constructed to detect the hub potential targets. In addition, GO and KEGG enrichment analysis were applied by Metascape database. Furthermore, we simultaneously investigated the anticancer effects of OP-B on SKOV3 and A2780 human ovarian cancer cells using a cell viability assay, transwell assay, and an image-based cytometric assay. The quantitative real-time PCR and western-blot assay were used to validate the RNA and protein levels of target genes in OP-B treated OC cells. At last, SKOV3-bearing BALB/c nude mice were applied to observe the effectiveness and toxicity of OP-B.

RESULTS

Through network pharmacological analysis, OP-B was found to play a critical role in OC via multiple targets and pathways, especially the STAT3 signaling pathways. In addition, in vitro experiments found OP-B suppressed SKOV3 and A2780 cells proliferation in a time and concentration dependent manner, and markedly impaired cancer cell migration. Flow cytometry analysis revealed that OP-B significantly increased early and late apoptosis, induced G2/M phase cell cycle arrest in SKOV3 cells and G0/G1 phase cell cycle arrest in A2780 cells. Moreover, OP-B administration down-regulated the expression of p-STAT3 protein, whereas the RNA expression and total protein levels of STAT3 were not altered. Finally, in vivo experiments confirmed the therapeutic effects of OP-B on OC in nude mice with low toxicity in heart, liver, lung, and kidney.

CONCLUSION

OP-B could efficiently suppress OC cellular proliferation, migration and induce apoptosis, cell cycle arrest mainly via the regulation of STAT3 signaling pathway. This study provides a promising potential application for an alternative to chemotherapy in ovarian cancer.

Inflammation, Fibrosis and Cancer: Mechanisms, Therapeutic Options and Challenges

Uncontrolled inflammation is a salient factor in multiple chronic inflammatory diseases and cancers. In this review, we provided an in-depth analysis of the relationships and distinctions between uncontrolled inflammation, fibrosis and cancers, while emphasizing the challenges and opportunities of developing novel therapies for the treatment and/or management of these diseases. We described how drug delivery systems, combination therapy and the integration of tissue-targeted and/or pathways selective strategies could overcome the challenges of current agents for managing and/or treating chronic inflammatory diseases and cancers. We also recognized the value of the re-evaluation of the disease-specific roles of multiple pathways implicated in the pathophysiology of chronic inflammatory diseases and cancers-as well as the application of data from single-cell RNA sequencing in the success of future drug discovery endeavors.

IL-10 Signaling Elicited by Nivolumab-Induced Activation of the MAP Kinase Pathway Does Not Fully Contribute to Nivolumab-Modulated Heterogeneous T Cell Responses

Immune checkpoint inhibitor (ICI) therapy has revolutionized anti-cancer treatment for many late-stage cancer patients. However, ICI therapy has thus far demonstrated limited efficacy for most patients, and it remains unclear why this is so. Interleukin 10 (IL-10) is a cytokine that has been recognized as a central player in cancer biology with its ability to inhibit anti-tumor T cell responses. Recent studies suggest that IL-10 might also exert some intrinsic anti-tumor T cell responses, and clinical studies using recombinant IL-10 alone or in combination with ICI are underway. This paradoxical effect of IL-10 and its underlying mechanisms impacting ICI-modulated T cell responses remain poorly understood. In this study, using an in vitro mixed lymphocyte reaction assay, we found that treatment with ICIs such as the anti-programmed cell death receptor-1 (PD-1) mAb nivolumab elicits a strong expression of IL-10. While neutralization of IL-10 signaling with an anti-IL-10 specific mAb significantly decreases the production of IFN-γ by T cells in a cohort of donor cells, the opposite effect was observed in other donor cells. Similarly, neutralization of IL-10 signaling significantly decreases the expression of T cell activation markers Ki67 and CD25, as well as the production of Granzyme B in a cohort of donor cells, whereas the opposite effect was observed in others. Furthermore, we found that nivolumab and IL-10 differentially modulate the signal transducer and activator of transcription 3 (STAT3) and AKT serine–threonine kinase pathways. Finally, we found that nivolumab activates the mitogen-activated protein kinase (MAPK) pathway, which in turn is responsible for the observed induction of IL-10 production by nivolumab. These findings provide new insights into the mechanisms underlying anti-PD-1-modulated T cell responses by IL-10, which could lead to the discovery of novel combination treatments that target IL-10 and immune checkpoint molecules.

MicroRNA-214 promotes alveolarization in neonatal rat models of bronchopulmonary dysplasia via the PlGF-dependent STAT3 pathway

BACKGROUND

Recently, the role of several microRNAs (miRNAs or miRs) in pulmonary diseases has been described. The molecular mechanisms by which miR-214 is possibly implicated in bronchopulmonary dysplasia (BPD) have not yet been addressed. Hence, this study aimed to investigate a putative role of miR-214 in alveolarization among preterm neonates with BPD.

METHODS

Microarray-based gene expression profiling data from BPD was employed to identify differentially expressed genes. A BPD neonatal rat model was induced by hyperoxia. Pulmonary epithelial cells were isolated from rats and exposed to hyperoxia to establish cell injury models. Gain- and loss-of-function experiments were performed in BPD neonatal rats and hyperoxic pulmonary epithelial cells. MiR-214 and PlGF expression in BPD neonatal rats, and eNOS, Bcl-2, c-myc, Survivin, α-SMA and E-cadherin expression in hyperoxic pulmonary epithelial cells were measured using RT-qPCR and Western blot analysis. The interaction between PlGF and miR-214 was identified using dual luciferase reporter gene and RIP assays. IL-1β, TNF-a, IL-6, ICAM-1 and Flt-1 expression in the rat models was measured using ELISA.

RESULTS

The lung tissues of neonatal rats with BPD showed decreased miR-214 expression with elevated PlGF expression. PlGF was found to be a target of miR-214, whereby miR-214 downregulated PlGF to inactivate the STAT3 pathway. miR-214 overexpression or PlGF silencing decreased the apoptosis of hyperoxic pulmonary epithelial cells in vitro and restored alveolarization in BPD neonatal rats.

CONCLUSION

Overall, the results demonstrated that miR-214 could facilitate alveolarization in preterm neonates with BPD by suppressing the PlGF-dependent STAT3 pathway.

Fascin1 mediated release of pro-inflammatory cytokines and invasion/migration in rheumatoid arthritis via the STAT3 pathway

Rheumatoid arthritis (RA) is a chronic, multi-factorial disease characterized by Synovial hyperplasia, chronic inflammation, and autoimmune reaction. Fascin1 overexpression has been implicated in cancer, immune, and inflammatory diseases. However, the relationship between Fascin1 and rheumatoid arthritis (RA) has not yet been determined. We investigated whether Fascin1 could modulate pro-inflammatory cytokine secretion and the proliferation, apoptosis, and invasion/migration of fibroblast-like synoviocytes (RA-FLSs). Fascin 1 was suppressed with a short interfering (si)RNA approach. Functional analysis contained MTT assay, flow cytometry,Transwell™ assays, wound healing, Quantitative polymerase chain reaction and western blotting were used to detect cell proliferation,apoptosis ratio, invasion/ migration, the mRNA and protein expression of the realted markers, respectively. Overexpression of fascin1 was observed in RA-FLSs group compared with control group. Fascin1 expression positively correlated with changes in the expression of RA disease activity markers (RF, CRP, and DAB28, respectively). We also observed a significant positive correlation between Fascin1 and STAT3 mRNA levels in RA- FLSs.Fascin1 silencing attenuated the expression of pro-inflammatory cytokines; reduced FLS proliferation in vitro; and increased apoptosis ratio and bax, cleaved PARP, and caspase-3 expression. si- Fascin1 transfection delayed RA-FLS invasion/migration and reversed the epithelial- mesenchymal transition. These data suggest that Fascin1 exerts positive effects on the proliferation, cell cycle, and invasion/migration of RA-FLSs by activating signal transducer and activator of transcription 3 signaling.After all, Fascin1 contributed to RA development.

IL-6/STAT3 pathway is involved in the regulation of autophagy in chronic non-bacterial prostatitis cells, and may be affected by the NLRP3 inflammasome

Studies have shown that the cytokine IL-6 plays an important role in the occurrence and development of chronic non-bacterial prostatitis (CNP), but the specific mechanism by which this cytokine regulates CNP is still unclear. At the same time, relevant research have also shown that autophagy is involved in regulating the occurrence and development of inflammation. The possible mechanisms are IL-6/STAT3 signaling pathway and NLRP3 inflammasome. On the basis of establishing the CNP model in rats, we found that IL-6 can regulate autophagy of CNP cells and is associated with the STAT3 pathway and NLRP3 inflammasome. Our results indicate that IL-6 is involved in the regulation of autophagy signaling pathways in CNP. IL-6/STAT3 signaling pathway can suppress cell autophagy pathway in CNP; And the NLRP3 inflammasome may regulate CNP cell autophagy by regulating the IL-6/STAT3 pathway. These findings may provide a new theoretical basis for the pathogenesis of CNP, as well as new ideas and new targets for the treatment and prevention of CNP.

Blockade of macrophage-associated programmed death 1 inhibits the pyroptosis signalling pathway in sepsis

OBJECTIVE

Programmed death 1 (PD-1) and macrophages are the most intriguing candidates in sepsis-induced inflammatory disorders. We aimed to investigate the association between monocyte PD-1 and sepsis severity and the mechanism by which blocking macrophage-associated PD-1 causes inflammatory disorders in sepsis.

MATERIALS AND METHODS

We first measured whether the expression of PD-1 on the monocyte subset is clinically associated with sepsis severity in an observational study. This study included 42 septic patients and 16 healthy controls (HCs) whose serum inflammatory factors were examined by Luminex MagPix. Then, we investigated the effect of PD-1 blockade on macrophages from septic mice (C57BL/6 mice) constructed by caecal ligation and puncture (CLP) via RNA sequencing. The positive genes screened by RNA-seq were verified in LPS-stimulated RAW264.7 cells by Western blot.

RESULTS

The results showed that the expression of PD-1 on CD14⁺CD16⁺ monocytes (intermediate monocytes, IM Mo) was significantly higher in both septic and septic shock patients than in HCs. Further analysis of serum cytokines in septic patients showed that the levels of IL-6 and TNF-α were significantly higher than those in HCs, while serum PD-1 levels were decreased in septic patients. More interestingly, blockade of PD-1 on macrophages from septic mice suppressed the gene expression levels of NLRP3/Caspase-4/AKT2/STAT3. The protein levels associated with pyroptosis including NLRP3, Caspase4, GSDMD and NT-GSDMD were significantly decreased in LPS-stimulated RAW264.7 cells treated with PD-1 antibody.

CONCLUSION

Our results suggested that intermediate monocytes with high expression of PD-1 may be involved in the progression of sepsis. PD-1 might play a critical role in regulating the pyroptosis signalling pathway in sepsis.

Glaucocalyxin A suppresses inflammatory responses and induces apoptosis in TNF-a-induced human rheumatoid arthritis via modulation of the STAT3 pathway

The pathogenesis of rheumatoid arthritis (RA) is characterized by synoviocyte hyperplasia and proinflammatory cytokine secretion, as well as the destruction of cartilage and bone. Glaucocalyxin A (GLA) is an alkaloid derived from a Chinese medicinal plant that exhibits anti-inflammatory, anti-tumor and neuroprotective properties. We investigated the effects of GLA on RA-fibroblast-like synoviocytes (FLS cells), and collagen-induced arthritis (CIA), and further explored the underlying mechanisms. GLA inhibited TNF-a-induced RA-FLS proliferation, increased apoptotic ratios and upregulated levels of caspase-3, cleaved PARP, and Bax. GLA also inhibited the expression of IL-10, IL-1β, and IL-6 in vitro. Levels of p-STAT3 were downregulated in a dose-dependent manner. Over-expression of STAT3 partly neutralized the GLA-mediated elevation of caspase-3 and cleaved PARP levels as well as the downregulation of IL-10, IL-1B and IL-6 expression levels. This suggests that GLA inactivated the STAT3 pathway. Furthermore, the production of inflammatory cytokines in RA-FLS and a CIA rat model were inhibited effectively by GLA. Taken together, our data suggest that GLA is a potential long-term therapeutic agent for patients with RA.

lncRNA MALAT1 Promotes Renal Fibrosis in Diabetic Nephropathy by Targeting the miR-2355-3p/IL6ST Axis

Long noncoding RNA (lncRNAs) metastasis–associated lung adenocarcinoma transcript 1 (MALAT1) has been reported in diabetic nephropathy (DN) about its effect on podocyte function and cell heat shock induced by hyperglycemia. However, the biological mechanism of MALAT1 regulating DN fibrosis needs further study. In this study, SD rats were administrated with streptozotocin (STZ) to establish a diabetes model. In vitro, human renal tubular epithelial cells (HK-2 and 293T) were treated with high glucose (HG). Here, we found that MALAT1 was upregulated in renal tissues of diabetic rats and HG-treated cells, and HG treatment promoted cell proliferation and invasion. MALAT1 overexpression aggravated protein levels of collagen I (col I), collagen IV (col IV), fibronectin (FN), and laminin (LN) in HK-2 cells, while MALAT1 knockdown exerted the opposite effect. Moreover, the luciferase reporter gene and pull-down assays demonstrated that MALAT1 interacted with miR-2355-3p. The miR-2355-3p level was downregulated in diabetic rats and HG-treated cells, and MALAT1 overexpression inhibited the miR-2355-3p level. Bioinformatics prediction and luciferase reporter gene assay revealed that interleukin 6 signal transducer (IL6ST) was a target of miR-2355-3p. In addition, miR-2355-3p overexpression attenuated fibrosis-related gene levels in HG-treated cells by inhibiting IL6ST expression and inactivating the recombinant signal transducer and activator of the transcription 3 (STAT3) signaling pathway. Knockdown of miR-2355-3p reversed the inhibitory effect of MALAT1 knockdown on IL6ST, col I, col IV, FN, and LN protein levels in HG-induced cells. Overexpression of MALAT1 aggravated cell damage in HG-induced cells via the miR-2355-3p/IL6ST/STAT3 signaling pathway. Finally, enhanced renal fibrosis and kidney tissue damage were observed in diabetic rats. In conclusion, MALAT1 overexpression may enhance renal fibrosis in diabetic rats and cell damage in HG-induced HK-2 cells via the miR-2355-3p/IL6ST axis, which provides a new perspective of DN treatment.

OCT4 induces embryonic pluripotency via STAT3 signaling and metabolic mechanisms

OCT4 is a fundamental component of the molecular circuitry governing pluripotency in vivo and in vitro. To determine how OCT4 establishes and protects the pluripotent lineage in the embryo, we used comparative single-cell transcriptomics and quantitative immunofluorescence on control and OCT4 null blastocyst inner cell masses at two developmental stages. Surprisingly, activation of most pluripotency-associated transcription factors in the early mouse embryo occurs independently of OCT4, with the exception of the JAK/STAT signaling machinery. Concurrently, OCT4 null inner cell masses ectopically activate a subset of trophectoderm-associated genes. Inspection of metabolic pathways implicates the regulation of rate-limiting glycolytic enzymes by OCT4, consistent with a role in sustaining glycolysis. Furthermore, up-regulation of the lysosomal pathway was specifically detected in OCT4 null embryos. This finding implicates a requirement for OCT4 in the production of normal trophectoderm. Collectively, our findings uncover regulation of cellular metabolism and biophysical properties as mechanisms by which OCT4 instructs pluripotency.

HnRNPA2B1 promotes the proliferation of breast cancer MCF-7 cells via the STAT3 pathway

HnRNPA2/B1 is highly expressed in many tumors. However, the role of hnRNPA2/B1 in breast cancer is not clear. In this study, we found the proliferation rate was decreased after knockout of hnRNPA2/B1 by CRISPR-CAS9 in MCF-7 cells, as demonstrated by the reduced expression of CDK4 and p-AKT, and the increased expression of P27. Besides this, the western blot results showed that knockout of hnRNPA2/B1 increased the rate of apoptosis and declined autophagy. By in vivo assay, we found that knockout of hnRNPA2/B1 suppressed tumor growth in a xenograft mouse model. Immunohistochemical staining results confirmed knockout of hnRNPA2/B1 impaired tumor angiogenesis, as illustrated by downregulated expression of VEGF-A. Besides this, interacting proteins with hnRNPA2/B1 were identified by mass spectrometry and the PPI network was constructed. GO analysis suggests that the Interacting proteins are mainly enriched in the Wnt signaling pathway, tumor necrosis factor-mediated signaling pathway, translation, and so on. We then identified hnRNPA2/B1 interacted with signal transducer and activator of transcription 3 (STAT3), as supported by the colocalization of hnRNPA2/B1 and STAT3. Meanwhile, knockout of hnRNPA2/B1 inhibited the phosphorylation of STAT3. Collectively, our results demonstrate that hnRNPA2/B1 promotes tumor cell growth in vitro and in vivo by activating the STAT3 pathway, regulating apoptosis and autophagy.

Saikosaponin D inhibits proliferation and induces apoptosis of non-small cell lung cancer cells by inhibiting the STAT3 pathway

OBJECTIVE

To study the effects of saikosaponin D (SSD) on proliferation and apoptosis in human non-small cell lung cancer cell lines, and to explore underlying mechanisms.

METHODS

Following treatment with saikosaponin D, A549 and H1299 cells were assessed for anti-proliferation effects using cell cycle kit-8 assays, changes in nuclear morphology using 4',6-diamidino-2-phenylindole (DAPI) staining, and cell apoptosis using annexin V/propidium iodide double staining. Proliferation- and apoptosis-related proteins were detected by immunoblotting.

RESULTS

Saikosaponin D had dose-dependent inhibitory effects on A549 cells (IC₅₀, 3.57 µM) and H1299 cells (IC₅₀, 8.46 µM). DAPI staining revealed decreased cell numbers, and most H1299 cells became round after treatment with 20 µM saikosaponin D. As saikosaponin D concentration increased, the proportions of cells in G0/G1 phase, and cells undergoing apoptosis, increased. Levels of phosphorylated p44/42 and signal transducer and activator of transcription (STAT)3 were significantly downregulated in both cell lines, while total STAT3 levels were not significantly affected. The cleaved form of caspase 3 was significantly upregulated.

CONCLUSIONS

Saikosaponin D inhibits proliferation, inducing cell cycle arrest and apoptosis, in lung cancer cells in a dose-dependent manner, possibly through inhibition of STAT3 phosphorylation and activation of caspase 3.

Protein tyrosine phosphatase receptor type delta (PTPRD) suppresses the expression of PD-L1 in human hepatocellular carcinoma by down-regulating STAT3

BACKGROUND

Protein tyrosine phosphatase receptor type delta (PTPRD) is a tumor suppressor that is often inactivated in hepatocellular carcinoma (HCC). However, the mechanisms of how PTPRD inhibits HCC are not well understood. Programmed cell death ligand 1 (PD-L1), an immune checkpoint, plays a seminal role in the regulation of carcinogenesis of HCC. The sustained activation of STAT3 is closely related to PTPRD deletion and PD-L1 overexpression; however, whether there is a relationship between PTPRD and PD-L1 expression in HCC has not been investigated. This study aims to investigate the relationship between PTPRD and PD-L1 in HCC samples and illuminate potential new molecular mechanisms of PTPRD effects on PD-L1 in HepG2 cells.

METHODS

We collected 16 pairs of tumorous tissues and adjacent normal tissues from HCC patients. The mRNA and protein expression levels of PTPRD and PD-L1 in the HCC tissues were detected by RT-PCR and Western blot analysis. Next, Spearman's correlation analysis was performed to evaluate the relationship between PTPRD and PD-L1. Then, we transfected the overexpressed or knocked-down PTPRD genes into the HepG2 cell line, and the effects of PTPRD on PD-L1 in HCC cells were evaluated. The activity from the STAT3 and p-STAT3 in the HepG2 cells transfected with PTPRD gene overexpression and knockdown was determined by Western blotting tests.

RESULTS

The expression of PTPRD was significantly down-regulated in the HCC tissues compared with the adjacent control tissues; however, PD-L1 was significantly higher in the HCC tissues. There was a negative correlation between PTPRD and PD-L1 expression in the HCC tissues. PTPRD over-expression significantly inhibited PD-L1 expression; meanwhile, PTPRD depletion promoted PD-L1 expression in the HepG2 cells. Furthermore, PTPRD over-expression significantly inhibited the expression of STAT3 and p-STAT3, while PTPRD depletion promoted these cytokines. Our studies revealed that PTPRD repressed PD-L1 expression in the HepG2 cells, which might occur via the STAT3 pathway.

CONCLUSIONS

The results from our study show that PTPRD and PD-L1 are negatively correlated in HCC tissues. PTPRD suppresses PD-L1 expression in HepG2 cells by down-regulating STAT3. These findings are expected to become a new target for the immunotherapy of HCC.

The Mechanism of Bacteroides fragilis Toxin Contributes to Colon Cancer Formation

The Bacteroides fragilis (B. fragilis) produce biofilm for colonisation in the intestinal tract can cause a series of inflammatory reactions due to B. fragilis toxin (BFT) which can lead to chronic intestinal inflammation and tissue injury and play a crucial role leading to colorectal cancer (CRC). The enterotoxigenic B. fragilis (ETBF) forms biofilm and produce toxin and play a role in CRC, whereas the non-toxigenic B. fragilis (NTBF) does not produce toxin. The ETBF triggers the expression of cyclooxygenase (COX)-2 that releases PGE2 for inducing inflammation and control cell proliferation. From chronic intestinal inflammation to cancer development, it involves signal transducers and activators of transcription (STAT)3 activation. STAT3 activates by the interaction between epithelial cells and BFT. Thus, regulatory T-cell (Tregs) will activates and reduce interleukin (IL)-2 amount. As the level of IL-2 drops, T-helper (T_h17) cells are generated leading to increase in IL-17 levels. IL-17 is implicated in early intestinal inflammation and promotes cancer cell survival and proliferation and consequently triggers IL-6 production that activate STAT3 pathway. Additionally, BFT degrades E-cadherin, hence alteration of signalling pathways can upregulate spermine oxidase leading to cell morphology and promote carcinogenesis and irreversible DNA damage. Patient with familial adenomatous polyposis (FAP) disease displays a high level of tumour load in the colon. This disease is caused by germline mutation of the adenomatous polyposis coli (APC) gene that increases bacterial adherence to the mucosa layer. Mutated-APC gene genotype with ETBF increases the chances of CRC development. Therefore, the colonisation of the ETBF in the intestinal tract depicts tumour aetiology can result in risk of hostility and effect on human health.

MiR-125b participates in the occurrence of preeclampsia by regulating the migration and invasion of extravillous trophoblastic cells through STAT3 signaling pathway

Preeclampsia (PE) is a major risk factor for maternal and fetal mortality. Studies showed that microRNAs (miRNAs) play important roles in PE, and are closely related to extra-villous trophoblastic proliferation and invasion. The current study determined miR-125b expression in PE patients, and explored the role of miR-125b in the occurrence and development of PE and its possible mechanism, aiming to provide a novel basis for the diagnosis and treatment of PE. The level of miR-125b in serum derived from pregnant women was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, invasion and migration of HTR-8/SVneo were determined by Cell Counting Kit-8 (CCK-8), Transwell and scratch assay, respectively. The target gene of miR-125b was predicted by Targetscan, and verified by luciferase reporter assay. The expressions of related proteins were determined by Western Blotting. The miR-125b level in the serum of PE patients was up-regulated as compared with normal pregnant women, and high level of miR-125b reduced cell proliferation, inhibited invasion and migration of HTR-8/SVneo as well as the expressions of STAT3, p-STAT3 and SOCS3, while low level of miR-125b produced the opposite results. STAT3 was predicted as the target gene of miR-125b, and the high level of miR-125b inhibited STAT3 signaling pathway. High expression of miR-125b may be involved in the occurrence of PE through inhibiting STAT3 pathway to inhibit the migration and invasion of extra-villous trophoblastic cells.

Desflurane pretreatment can reduce sepsis-evoked lung injury in rats via inhibiting STAT3 pathway

The purpose of this study was to investigate the effect of desflurane (Des) pretreatment on sepsisevoked lung injury in rats and its mechanism. The rat model of sepsis-evoked lung injury was prepared using lipopolysaccharide (LPS), while rat lung mesenchymal cell (MSC) model was cultured in vitro, followed by Des pretreatment or inhibitor S31-201 culture. The degree of lung tissue injury was analyzed by Hematoxylin-eosin (HE) staining. The expression levels of interleukin (IL)-6, IL-1β and tumor necrosis factor (TNF)-α in the serum of rats were detected by enzyme-linked immunosorbent assay (ELISA). One-step terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay was utilized to determine the apoptosis levels of lung tissues and MSCs cultured in vitro. The expressions of the signal transducer and activator of transcription 3 (STAT3) pathway in rat lung tissues and MSCs were detected by Western blotting. After modeling, LPS induced the lung injury in rats, the expression levels of IL-6, IL-1β and TNF-α were up-regulated (P<0.05), the apoptosis rate was increased (P<0.05), and phosphorylated-Janus kinase 2 (p-JAK2) and phosphorylated-STAT3 (p-STAT3) protein expressions were up-regulated (P<0.05). Des pretreatment can alleviate LPS-induced lung injury, down-regulate IL-6, IL-1β and TNF-α expression levels (P<0.05), reduce apoptosis (P<0.05), and downregulate p-JAK2 and p-STAT3 protein levels (P<0.05). LPS induced an increase in apoptosis rate of MSCs (P<0.05) and the up-regulation of p-STAT3 protein expression (P<0.05). Both Des pretreatment and S31-201 inhibitor culture could reduce the apoptosis rate (P<0.05) and down-regulate p-STAT3 protein level (P<0.05). Des pretreatment can reduce sepsis-evoked lung injury in rats, which may be related to the inhibition of protein expressions of STAT3 pathway.

2'-Hydroxyflavanone inhibits the progression of pancreatic cancer cells and sensitizes the chemosensitivity of EGFR inhibitors via repressing STAT3 signaling

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies, and chemotherapy is still an important treatment. It is urgent to develop new medicines because of the limitation and side effects of chemotherapy. 2'-Hydroxyflavanone (2HF) is a citrus-bioflavonoid that is considered to have anti-cancer efficacy. Compared to human pancreatic ductal epithelial cells hTERT-HPNE, more significant growth-inhibitory effects were seen in PDAC cells BxPC-3 and MIA PaCa-2. We showed that apoptosis was induced and that the cell cycle was arrested when cells were treated with 2HF. The expression of the molecular proteins cleaved PARP, cleaved Caspase3, Bax, Bcl-2, CyclinD1, and p27 changed correspondingly. Also, we observed anti-metastatic effects and changes in MMP9, E-cadherin, N-cadherin and Vimentin when cells were treated with a low dose of 2HF. Suppression of STAT3 and EGFR phosphorylation was also identified as a result of treatment with a combination of 2HF and EGFR inhibitors. The in vivo antitumor effects in KPC mice were consistent with those observed in vitro. 2HF has impactful anti-cancer efficacy and sensitizes human pancreatic cancer cells to EGFR inhibitors through the inhibition of STAT3.

Brain-derived neurotrophic factor alleviates diabetes mellitus-accelerated atherosclerosis by promoting M2 polarization of macrophages through repressing the STAT3 pathway

Diabetes mellitus-accelerated atherosclerosis (DMAS) is one of the vascular complications of diabetes. Brain-derived neurotrophic factor (BDNF) plays a critical role in diabetes mellitus. However, the mechanism by which BDNF is involved in DMAS remains unknown. This study investigates the effect of BDNF on the progression of DMAS as well as the underlying mechanism of action. The levels of BDNF in serum and peripheral blood mononuclear cells (PBMCs) from patients with DMAS and health controls were measured as well as the expression of inflammatory cytokines (IL-1β, TNF-α, IL-10, TGF-β and IL-13). The effects of BDNF restoration on cytokine release, macrophage differentiation and the formation of atherosclerotic plaques were evaluated both in vitro and in vivo using the DMAS mouse model. Downregulation of BDNF was identified in the serum and PBMCs of patients with DMAS. Elevation of BDNF contributed to a reduction in the AS lesion area in low-density lipoprotein receptor^-/- mice, inactivated the STAT3 pathway, decreased pro-inflammatory cytokines IL-1β and TNF-α, and increased IL-10, TGF-β and IL-13. BDNF overexpression also increased the proportion of M2 macrophages and alleviated atherosclerotic lesions. Our findings demonstrate that BDNF overexpression promotes M2 macrophage polarization, which represses the development of DMAS by inactivating the STAT3 pathway.

Novel 3D organotypic urothelial cell culture model for identification of new therapeutic approaches in urological infections

PURPOSE

3D organotypic cell cultures offer the possibility to study cell growth in a more in vivo like situation. To our knowledge no 3D culture of primary urothelial cells has been established yet. BK Polyomavirus (BKPyV), replicating in urothelial cells, may cause haemorrhagic cystitis in immunocompromised patients.

PRIMARY ENDPOINTS OF THIS STUDY

Establishment of a 3D organotypic cell culture of primary urothelial cells and fibroblasts; use of this model as infection model for archetype BKPyV; description of first parts of viral life cycle with identification of therapeutic targets.

METHODS

This is an experimental study. Primary urothelial cells were purchased from CellnTec, Bern, Switzerland; fibroblasts were isolated from the ureter of patients with no urothelial malignancy in their medical history. As main methods we used quantitative real-time PCR and immunohistochemistry. Outcomes were analysed using SPSS 23.0.

RESULTS

We were able to develop a 3D organotypic culture for primary urothelium. An infection with archetype BKPyV was established in this model with virus replication rates up to 6.41 × 108 copies/ml on day 9 following Infection. Interestingly, proliferation rate of the urothelial cells is significantly (p = 0.049 at day 6 following infection) elevated while cells are losing differentiation under infection. Phosphorylated STAT3 is also significantly elevated (p < 0.0001) during infection.

CONCLUSIONS

The established of urothelial 3D cultures is a new method to study several urothelial diseases. The archetype BKPyV infection model is novel and the first method to study archetype viral life cycle. The STAT3 pathway might be an interesting target for the development of a causal therapy.

CoCl2 , a mimic of hypoxia, enhances bone marrow mesenchymal stem cells migration and osteogenic differentiation via STAT3 signaling pathway

Mesenchymal stem cells homing and migration is a crucial step during bone fracture healing. Hypoxic environment in fracture site induces bone marrow mesenchymal stem cells (BMSCs) migration, but its mechanism remains unclear. Our previous study and studies by other groups have reported the involvement of signal transducer and activator of transcription 3 (STAT3) pathway in cell migration. However, the role of STAT3 pathway in hypoxia-induced cell migration is still unknown. In this study, we investigated the role of STAT3 signaling in hypoxia-induced BMSCs migration and osteogenic differentiation. BMSCs isolated from C57BL/6 male mice were cultured in the presence of cobalt chloride (CoCl₂ ) to simulate intracellular hypoxia. Hypoxia enhanced BMSCs migration, and upregulated cell migration related gene expression, that is, metalloproteinase (MMP) 7, MMP9, and C-X-C motif chemokine receptor 4. Hypoxia enhanced the phosphorylation of STAT3, and cell migration related proteins: c-jun n-terminal kinase (JNK), focal of adhesion kinase (FAK), extracellular regulated protein kinases, and protein kinase B 1/2 (ERK1/2). Moreover, hypoxia enhanced expression of osteogenic differentiation marker. Inhibition of STAT3 suppressed the hypoxia-induced BMSCs migration, cell migration related signaling molecules phosphorylation, and osteogenic differentiation related gene expression. In conclusion, our result indicates that hypoxia-induced BMSCs migration and osteogenic differentiation is via STAT3 phosphorylation and involves the cooperative activity of the JNK, FAK, and MMP9 signaling pathways.

Novel quinazoline-based sulfonamide derivative (3D) induces apoptosis in colorectal cancer by inhibiting JAK2-STAT3 pathway

Introduction

Colorectal cancer (CRC) is a major worldwide health problem owing to its high prevalence and mortality rate. Developments in screening, prevention, biomarker, personalized therapies and chemotherapy have improved detection and treatment. However, despite these advances, many patients with advanced metastatic tumors still succumb to the disease. New anticancer agents are needed for treating advanced stage CRC as most of the deaths occur due to cancer metastasis. A recently developed novel sulfonamide derivative 4-((2-(4-(dimethylamino) phenyl)quinazolin-4-yl)amino)benzenesulfonamide (3D) has shown potent antitumor effect; however, the mechanism underlying the antitumor effect remains unknown.

Materials and methods

3D-mediated inhibition on cell viability was evaluated by MTT and real-time cell proliferation was measured by xCelligence RTDP instrument. Western blotting was used to measure pro-apoptotic, anti-apoptotic proteins and JAK2-STAT3 phosphorylation. Flow cytometry was used to measure ROS production and apoptosis.

Results

Our study revealed that 3D treatment significantly reduced the viability of human CRC cells HT-29 and SW620. Furthermore, 3D treatment induced the generation of reactive oxygen species (ROS) in human CRC cells. Confirming our observation, N-acetylcysteine significantly inhibited apoptosis. This is further evidenced by the induction of p53 and Bax; release of cytochrome c; activation of caspase-9, caspase-7 and caspase-3; and cleavage of PARP in 3D-treated cells. This compound was found to have a significant effect on the inhibition of antiapoptotic proteins Bcl2 and BclxL. The results further demonstrate that 3D inhibits JAK2–STAT3 pathway by decreasing the constitutive and IL-6-induced phosphorylation of STAT3. 3D also decreases STAT3 target genes such as cyclin D1 and survivin. Furthermore, a combination study of 3D with doxorubicin (Dox) also showed more potent effects than single treatment of Dox in the inhibition of cell viability.

Conclusion

Taken together, these findings indicate that 3D induces ROS-mediated apoptosis and inhibits JAK2–STAT3 signaling in CRC.

Opposite Interplay Between the Canonical WNT/β-Catenin Pathway and PPAR Gamma: A Potential Therapeutic Target in Gliomas

In gliomas, the canonical Wingless/Int (WNT)/β-catenin pathway is increased while peroxisome proliferator-activated receptor gamma (PPAR-γ) is downregulated. The two systems act in an opposite manner. This review focuses on the interplay between WNT/β-catenin signaling and PPAR-γ and their metabolic implications as potential therapeutic target in gliomas. Activation of the WNT/β-catenin pathway stimulates the transcription of genes involved in proliferation, invasion, nucleotide synthesis, tumor growth, and angiogenesis. Activation of PPAR-γ agonists inhibits various signaling pathways such as the JAK/STAT, WNT/β-catenin, and PI3K/Akt pathways, which reduces tumor growth, cell proliferation, cell invasiveness, and angiogenesis. Nonsteroidal anti-inflammatory drugs, curcumin, antipsychotic drugs, adiponectin, and sulforaphane downregulate the WNT/β-catenin pathway through the upregulation of PPAR-γ and thus appear to provide an interesting therapeutic approach for gliomas. Temozolomide (TMZ) is an antiangiogenic agent. The downstream action of this opposite interplay may explain the TMZ-resistance often reported in gliomas.

STAT3 activation by IL-6 from adipose-derived stem cells promotes endometrial carcinoma proliferation and metastasis

Endometrial cancer is the most common gynaecological cancer, and its incidence is increasing. Obesity is a well-recognized risk factor for endometrial cancer, and the mechanisms by which adipose tissue influences tumour development remain controversial. In this study, we examined the high IL-6 level in the ADSCs supernatant following treatment of endometrial cancer cell CM. Then, the activation of STAT3, a major tumourigenic IL-6 effector, was examined in ADSCs CM treated endometrial cancer cells. Conditioned ADSC medium was used to stimulate endometrial cancer cell growth in vitro. Similar to IL-6, ADSC-conditioned medium significantly promoted endometrial cancer growth and invasion. Furthermore, siRNA-mediated STAT3 inhibition in endometrial cancer cells decreased the ADSC-mediated promotion of cell proliferation and invasion. In addition, a subcutaneous nude mouse model of endometrial cancer was established to monitor the tumour-promoting effect of ADSCs. ADSC-conditioned medium promoted tumour growth, and STAT3 inhibition attenuated this effect. Based on these data, ADSCs promote endometrial cancer progression by the STAT3 signalling pathway.

Caryophyllane sesquiterpenes inhibit DNA-damage by tobacco smoke in bacterial and mammalian cells

In the present study, the ability of the natural sesquiterpene β-caryophyllene (CRY) and its metabolite β-caryophyllene oxide (CRYO) to inhibit the genotoxicity of a condensate of cigarette smoke (CSC) was evaluated both in bacterial and mammalian cells. Also, the inhibition of the CSC-mediated STAT3 phosphorylation and intracellular oxidative stress was evaluated as potential chemopreventive mechanism. Under our experimental conditions, both the sesquiterpenes exhibited antimutagenic properties, being CRY the most potent compound. The antimutagenicity was highlighted in all experimental protocols, being particularly strong in the co- and post-treatments. The test substances also reduced the micronuclei frequency induced by CSC, with a major effectiveness of CRY. CRY was also able to reduce the CSC-mediated increase of the Y705- pSTAT3 levels, in spite of a lacking effect of CRYO. Furthermore, the sesquiterpenes CRY and CRYO displayed a moderate antioxidant activity, with a 25 % and 40 % inhibition of the ROS-levels increased by CSC, respectively. On the basis of these results, CRY seems to be a multi-target chemopreventive agent, although the genoprotective and antioxidant effects of CRYO suggest that both compounds deserve to be deeply investigated for a possible application in the prevention and treatment of different smoke-related ailments.

Empagliflozin Limits Myocardial Infarction in Vivo and Cell Death in Vitro: Role of STAT3, Mitochondria, and Redox Aspects

Empagliflozin (EMPA), a drug approved for type 2 diabetes management, reduced cardiovascular death but is unknown if it reduces myocardial infarction. We sought to investigate: (i) the effect of EMPA on myocardial function and infarct size after ischemia/reperfusion in mice fed with western diet (WD), (ii) the underlying signaling pathways, (iii) its effects on cell survival in rat embryonic-heart-derived cardiomyoblasts (H9C2) and endothelial cells (ECs). To facilitate the aforementioned aims, mice were initially randomized in Control and EMPA groups and were subjected to 30 min ischemia and 2 h reperfusion. EMPA reduced body weight, blood glucose levels, and mean arterial pressure. Cholesterol, triglyceride, and AGEs remained unchanged. Left ventricular fractional shortening was improved (43.97 ± 0.92 vs. 40.75 ± 0.61%) and infarct size reduced (33.2 ± 0.01 vs. 17.6 ± 0.02%). In a second series of experiments, mice were subjected to the above interventions up to the 10th min of reperfusion and myocardial biopsies were obtained for assessment of the signaling cascade. STAT3 was increased in parallel with reduced levels of malondialdehyde (MDA) and reduced expression of myocardial iNOS and interleukin-6. Cell viability and ATP content were increased in H9C2 and in ECs. While, STAT3 phosphorylation is known to bestow infarct sparing properties through interaction with mitochondria, we observed that EMPA did not directly alter the mitochondrial calcium retention capacity (CRC); therefore, its effect in reducing myocardial infarction is STAT3 dependent. In conclusion, EMPA improves myocardial function and reduces infarct size as well as improves redox regulation by decreasing iNOS expression and subsequently lipid peroxidation as shown by its surrogate marker MDA. The mechanisms of action implicate the activation of STAT3 anti-oxidant and anti-inflammatory properties.

Silibinin sensitizes chemo-resistant breast cancer cells to chemotherapy

CONTEXT

Multiple drug resistance is the major obstacle to conventional chemotherapy. Silibinin, a nontoxic naturally occurring compound, has anticancer activity and can increase the cytotoxic effects of chemotherapy in various cancer models.

OBJECTIVE

To evaluate the effects of silibinin on enhancing the sensitivity of chemo-resistant human breast cell lines to doxorubicin (DOX) and paclitaxel (PAC).

MATERIALS AND METHODS

The cells were treated with silibinin (at 50 to 600 μM concentrations) and/or chemo drugs for 24 and 48 h, then cell viability and changes in oncogenic proteins were determined by MTT assay and Western blotting/RT-PCR, respectively. Flow cytometry was used to study apoptosis in the cells receiving different treatments. The antitumorigenic effects of silibinin (at 200 to 400 μM concentration) were evaluated by mammosphere assay.

RESULTS

Silibinin exerted significant growth inhibitory effects with IC₅₀ ranging from 200 to 570 μM in different cell lines. Treatment of DOX-resistant MDA-MB-435 cells with silibinin at 200 μM reduced DOX IC₅₀ from 71 to 10 μg/mL and significantly suppressed the key oncogenic pathways including STAT3, AKT, and ERK in these cells. Interestingly treatment of DOX-resistant MDA-MB-435 cells with silibinin at 400 μM concentration for 48 h induced a 50% decrease in the numbers of colonies as compared with DMSO-treated cells. Treatment of PAC-resistant MCF-7 cells with silibinin at 400 μM concentration generated synergistic effects when it was used in combination with PAC at 250 nM concentration (CI = 0.81).

CONCLUSION

Silibinin sensitizes chemo-resistant cells to chemotherapeutic agents and can be useful in treating breast cancers.

Mechanism of action of selective inhibitors of IL-6 induced STAT3 pathway in head and neck cancer cell lines

Studies indicate that elevated interleukin-6 (IL-6) levels engage IL6Rα-gp130 receptor complexes to activate signal transducer and activator of transcription 3 (STAT3) that is hyperactivated in many cancers including head and neck squamous cell carcinoma (HNSCC). Our previous HCS campaign identified several hits that selectively blocked IL-6-induced STAT3 activation. This study describes our investigation of the mechanism(s) of action of three of the four chemical series that progressed to lead activities: a triazolothiadiazine (864669), amino alcohol (856350), and an oxazole-piperazine (4248543). We demonstrated that all three blocked IL-6-induced upregulation of the cyclin D1 and Bcl-X_L STAT3 target genes. None of the compounds exhibited direct binding interactions with STAT3 in surface plasmon resonance (SPR) binding assays; neither did they inhibit the recruitment and binding of a phospho-tyrosine-gp130 peptide to STAT3 in a fluorescence polarization assay. Furthermore, they exhibited little or no inhibition in a panel of 83 cancer-associated in vitro kinase profiling assays, including lack of inhibition of IL-6-induced Janus kinase (JAK 1, 2, and 3) activation. Further, 864669 and 4248543 selectively inhibited IL-6-induced STAT3 activation but not that induced by oncostatin M (OSM). The compounds 864669 and 4248543 abrogated IL-6-induced phosphorylation of the gp130 signaling subunit (phospho-gp130Y₉₀₅) of the IL-6-receptor complex in HNSCC cell lines which generate docking sites for the SH2 domains of STAT3. Our data indicate that 864669 and 4248543 block IL-6-induced STAT activation by interfering with the recruitment, assembly, or activation of the hexamer-activated IL-6/IL-6Rα/gp130 signaling complex that occurs after IL-6 binding to IL-6Rα subunits.

Let-7a-transfected mesenchymal stem cells ameliorate monocrotaline-induced pulmonary hypertension by suppressing pulmonary artery smooth muscle cell growth through STAT3-BMPR2 signaling

Background

Cell-based gene therapy has become a subject of interest for the treatment of pulmonary arterial hypertension (PAH), a devastating disease characterized by pulmonary artery smooth muscle cell (PASMC) hyperplasia. Mesenchymal stem cells (MSCs) have been recently acknowledged as a potential cell vector for gene therapy. Here, we investigated the effect of MSC-based let-7a for PAH.

Methods

After isolation and identification of MSCs from rat bone marrow, cells were infected with recombinant adenovirus vector Ad-let-7a. Lewis rats were subcutaneously injected with monocrotaline (MCT) to induce PAH, followed by the administration of MSCs, MSCs-NC (miR-control), or MSC-let-7a, respectively. Then, right ventricular systolic pressure (RVSP), right ventricular hypertrophy, and pulmonary vascular remodeling were evaluated. Rat pulmonary artery smooth muscle cells (rPASMCs) under hypoxia were co-cultured with MSCs or MSC-let-7a. Cell proliferation and apoptosis were separately determined by ³H thymidine incorporation and flow cytometry analysis. The underlying mechanism was also investigated.

Results

MSC transplantation enhanced let-7a levels in MCT-induced PAH rats. After injection with MSC-let-7a, RVSP, right ventricular hypertrophy, and pulmonary vascular remodeling were notably ameliorated, indicating a protective effect of MSC-let-7a against PAH. When co-cultured with MSC-let-7a, hypoxia-triggered PASMC proliferation was obviously attenuated, concomitant with the decrease in cell proliferation-associated proteins. Simultaneously, the resistance of PASMCs to apoptosis was remarkably abrogated by MSC-let-7a administration. A mechanism assay revealed that MSC-let-7a restrained the activation of signal transducers and activators of transcription 3 (STAT3) and increased its downstream bone morphogenetic protein receptor 2 (BMPR2) expression. Importantly, preconditioning with BMPR2 siRNA dramatically abated the suppressive effects of MSC-let-7a on PASMC proliferation and apoptosis resistance.

Conclusions

Collectively, this study suggests that MSCs modified with let-7a may ameliorate the progression of PAH by inhibiting PASMC growth through the STAT3-BMPR2 signaling, supporting a promising therapeutic strategy for PAH patients.

2-Guanidinoquinazolines as new inhibitors of the STAT3 pathway

Synthesis and SAR investigation of 2-guanidinoquinazolines, initially identified in a high content screen for selective STAT3 pathway inhibitors, led to a more potent analog (11c) that demonstrated improved anti-proliferative activity against a panel of HNSCC cell lines.

Hedyotis diffusa Willd inhibits colorectal cancer growth in vivo via inhibition of STAT3 signaling pathway

Signal Transducer and Activator of Transcription 3 (STAT3), a common oncogenic mediator, is constitutively activated in many types of human cancers; therefore it is a major focus in the development of novel anti-cancer agents. Hedyotis diffusa Willd has been used as a major component in several Chinese medicine formulas for the clinical treatment of colorectal cancer (CRC). However, the precise mechanism of its anti-tumor activity remains largely unclear. Using a CRC mouse xenograft model, in the present study we evaluated the effect of the ethanol extract of Hedyotis diffusa Willd (EEHDW) on tumor growth in vivo and investigated the underlying molecular mechanisms. We found that EEHDW reduced tumor volume and tumor weight, but had no effect on body weight gain in CRC mice, demonstrating that EEHDW can inhibit CRC growth in vivo without apparent adverse effect. In addition, EEHDW treatment suppressed STAT3 phosphorylation in tumor tissues, which in turn resulted in the promotion of cancer cell apoptosis and inhibition of proliferation. Moreover, EEHDW treatment altered the expression pattern of several important target genes of the STAT3 signaling pathway, i.e., decreased expression of Cyclin D1, CDK4 and Bcl-2 as well as up-regulated p21 and Bax. These results suggest that suppression of the STAT3 pathway might be one of the mechanisms by which EEHDW treats colorectal cancer.