p-STAT3 Protein Expression Research Articles

IL-21 enhances STAT3/Blimp-1 signaling pathway in B cells and contributes to plasma cell differentiation in newly diagnosed patients with myasthenia gravis.

The transcription factor Blimp-1 is necessary for the B cell differentiation toward immunoglobulin-secreting plasma cells. However, the immunopathological mechanisms of Blimp-1 that regulates B cell differentiation remain unclear in MG. The purpose of this study was to perform a quantitative and functional analysis of Blimp-1 in MG. A total of 34 patients with MG (18 ocular MG (OMG) and 16 generalized MG (GMG) and 20 healthy controls (HC) were recruited in this study. CD19+ B cells were isolated by positive selection using CD19 beads. The expression of Blimp-1 and p-STAT3 protein in isolated B cells was assessed by Western blot. Plasma cells were analyzed by flow cytometry. Serum IL-21 levels were detected by ELISA. Our data demonstrated that Blimp-1 in peripheral blood B cell of MG patients was significantly increased compared with HC. The increased expression of Blimp-1 was positively associated with clinical severity score (QMGs), plasma cell frequency, and serum IL-21 levels. Furthermore, glucocorticoid (GC) treatment reduced the expression of Blimp-1 and p-STAT3 in B cells, and this change was accompanied with relieved clinical severity, reduced plasma cell frequency, and decreased serum IL-21 levels. In vitro assay demonstrated that IL-21 stimulation upregulated STAT3 phosphorylation, increased Blimp-1 expression in B cells, and promoted plasma cell differentiation, and these processes could be inhibited by dexamethasone or STAT3 inhibitor stattic. This work indicates for the first time that aberrant expression of Blimp-1 exists on B cells and contributes to the plasma cell differentiation in MG patients. Modulation of IL-21/STAT3/Blimp-1 signaling pathway in B cells may be one of the mechanisms of glucocorticoid in the treatment of MG.

Silencing PBX1 expression induces apoptosis and ROS production of lung cancer cells

Objective: To investigate the effects of pre-B lymphocytic leukemia transcription factor (PBX1) expression on the apoptosis, reactive oxygen species (ROS) content and transcriptional activation factor 3 (STAT3) signaling pathway of lung cancer cells. Methods: Real-time quantitative polymerase chain reaction was used to detect the expression level of PBX1 in lung cancer tissues and adjacent tissues. The correlation between PBX1 expression level and clinical pathological parameters of patients were analyzed. Western blot was used to detect the protein expression level of PBX1 in human lung cancer cell lines, including A549, SPC-A1, SK-MES-1 and H1299. A549 cells were transfected with blank control (blank group), negative control (NC group) or PBX1 small interfering RNA (siRNA group), respectively. The cells apoptosis and ROS content were detected by flow cytometry. The protein expression levels of PBX1, STAT3, phosphorylated STAT3 (p-STAT3), B cell lymphoma/leukemia-2 (Bcl-2) and survivin in each group were detected by western blot. Results: The expression level of PBX1 mRNA in lung cancer was (2.36±0.23), significantly higher than (1.02±0.15) in paracancerous tissues (P<0.05). The expression level of PBX1 was correlated with lung cancer differentiation, lymph node metastasis and TNM stage (P<0.05). The expression levels of PBX1 in human lung cancer cells A549, SPC-A1, SK-MES-1 and H1299 were (0.454±0.038), (0.403±0.034), (0.311±0.028) and (0.377±0.035), respectively, significantly higher than (0.041±0.007) of human normal lung cells MRC-5 (P<0.05). The expression level of PBX1 protein in A549 cells transfected with PBX1 siRNA was (0.082±0.010), significantly lower than (0.704±0.065) of the blank group (P<0.05). The apoptosis rate and ROS content of siPBX1 group were (30.78±3.64)% and (51.55±5.03), respectively, significantly higher than (3.92±0.27)% and (22.36±1.31) of blank group (P<0.05). The protein expressions of p-STAT3, Bcl-2 and survivin were (0.051±0.006), (0.202±0.018) and (0.068±0.008), respectively, significantly lower than (0.172±0.010), (0.425±0.041) and (0.196±0.021) of blank group (P<0.05). Conclusion: Inhibition of PBX1 expression can induce the apoptosis of lung cancer cell, the mechanism may be related to ROS production and down-regulation of STAT3 signal.

Sheng-Mai Yin exerts anti-inflammatory effects on RAW 264.7 cells and zebrafish

Ethnopharmacological relevanceSheng-Mai Yin (SMY), a famous traditional Chinese medicine formula, has been commonly used in China for centuries to treat various diseases, such as inflammation-related diseases. However, the anti-inflammatory activity of SMY and its potential mechanisms still have not yet been clearly understood.Aim of the study: In this study, we aimed to determine the anti-inflammatory effect of SMY and explore its underlying mechanisms both on RAW 264.7 cells and zebrafish. Materials and methodsThe levels of pro-inflammatory cytokines IL-6 and TNF-α secreted by RAW 264.7 cells were measured by ELISA. The protein expressions of IκBα, p-IκBα (Ser32), STAT3 and p-STAT3 (Tyr705) were determined by Western blotting. And the nuclear translocation of NF-κB p65 in LPS-induced RAW 264.7 macrophage cells was detected by confocal microscopy. Moreover, the in vivo anti-inflammatory effect of SMY and its potential mechanisms were further investigated by survival analysis, hematoxylin-eosin staining (H&E), observation of neutrophil migration and quantitative real-time PCR (qRT-PCR) analysis in zebrafish inflammatory models. ResultsSMY reduced the release of IL-6 and TNF-α, inhibited the phosphorylation of IκBα and STAT3 as well as the nuclear translocation of NF-κB p65 in LPS-induced RAW 264.7 cells. Furthermore, the increased survival, decreased infiltration of inflammatory cells and the attenuated migration of neutrophils together suggested the in vivo anti-inflammatory effects of SMY. More importantly, SMY reduced the gene expressions of pro-inflammatory cytokines and suppressed LPS-induced up-regulation of NF-κB, IκBα and STAT3 in zebrafish inflammatory models. ConclusionSMY exerts significant anti-inflammatory effects with a potential mechanism of inhibiting the NF-κB and STAT3 signal pathways. Our findings suggest a scientific rationale of SMY to treat inflammatory diseases in clinic.

Protective effects of citrulline supplementation in ulcerative colitis rats.

It has been reported that supplementing certain amino acids has therapeutic effects on ulcerative colitis (UC). We intend to explore whether citrulline (Cit) supplementation has protective effects on UC. Fifteen male Wistar rats were divided into normal control group (NC group), UC group and UC+Cit group, with five rats in each group. The UC model was established by TNBS/ethanol method. Rats in UC+Cit group were intragastrically administered with Cit for 7 consecutive days after modeling. All rats were sacrificed after 7 days. Blood samples were collected to detect the number of monocytes. Colon tissues were taken for HE staining. Immunohistochemistry staining for CD68 and p-STAT3 were performed to detect the infiltration of monocytes and the phosphorylation of STAT3 in colon tissues. The concentrations of MCP-1, IL-6 and IL-17A and the protein expression of p-STAT3 in colon tissues were measured by ELISA and western blot methods, respectively. The body weight of UC group rats decreased significantly after 7 days (p<0.05). However, the weight loss of UC+Cit group rats was not statistically significant (p>0.05). The number of peripheral blood monocytes in UC+Cit group was significantly lower than that in UC group (p<0.05), and the infiltration of CD68-positive monocytes in the colon tissue of UC+Cit group was significantly reduced than that in UC group. The concentrations of MCP-1, IL-6 and IL-17A and the expression of p-STAT3 in colon tissues of UC+Cit group rats were significantly lower than those in UC group (both p<0.05). Our study suggests that Cit supplementation may be a potential therapy for UC.

Concurrent Targeting of Potential Cancer Stem Cells Regulating Pathways Sensitizes Lung Adenocarcinoma to Standard Chemotherapy.

Cancer stem cells (CSC) are highly resistant to conventional chemotherapeutic drugs. YAP1 and STAT3 are the two transcription factors that facilitate the therapeutic resistance and expansion of CSCs. The objective of this study was to understand the cross-talk between YAP1 and STAT3 activities and to determine the therapeutic efficacy of targeting dual CSC-regulating pathways (YAP1 and STAT3) combined with chemotherapy in lung adenocarcinoma. Here, we showed that YAP1 contributes to CSC regulation and enhances tumor formation while suppressing apoptosis. Mechanistically, YAP1 promotes phosphorylation of STAT3 by upregulating IL6. In lung adenocarcinoma clinical specimens, YAP1 expression correlated with that of IL6 (P < 0.01). More importantly, YAP1 and phosphorylated STAT3 (pSTAT3) protein expressions were significantly correlated (P < 0.0001) in primary lung adenocarcinoma as determined by IHC. Immunoblotting of 13 lung adenocarcinoma patient-derived xenografts (PDX) showed that all YAP1-expressing PDXs also exhibited pSTAT3. Additional investigations revealed that chemotherapy resistance and malignant stemness were influenced by upregulating NANOG, OCT4, and SOX2, and the expression of these targets significantly attenuated by genetically and pharmacologically hindering the activities of YAP1 and STAT3 in vivo and in vitro Therapeutically, the dual inhibition of YAP1 and STAT3 elicits a long-lasting therapeutic response by limiting CSC expansion following chemotherapy in cell line xenograft and PDX models of lung adenocarcinoma. Collectively, these findings provide a conceptual framework to target the YAP1 and STAT3 pathways concurrently with systemic chemotherapy to improve the clinical management of lung adenocarcinoma, based on evidence that these two pathways expand CSC populations that mediate resistance to chemotherapy.

Effects of ethyl acetate extract of peony (Paeonia suffruticosa) seed coat on the proliferation and apoptosis of oral squamous carcinoma cells through miR-424-3p/STAT3/Survivin pathway

Oral squamous cell carcinoma is one of the most common high malignant tumors. This experiment aimed to investigate whether ethyl acetate extract of peony (Paeonia suffruticosa) seed coat could affect the proliferation and apoptosis of oral squamous carcinoma cells by regulating the miR-424-3p/STAT3/Survivin pathway. For this purpose, oral squamous cell carcinoma cell CAL27 was cultured in vitro, and cells were treated with ethyl acetate extract of peony seed coat at different concentrations. MTT was used to detect cell proliferation. Flow cytometry was used to detect apoptosis. qRT-PCR was used to detect the expression level of miR-424-3p. The miR-424-3p mimics and anti-miR-424-3p were transfected into CAL27 cells respectively, and the cell proliferation and apoptosis were detected by the above method. Western blot method was used to detect the expression of PCNA, Bcl-2, Bax, p-STAT3 and Survivin protein. Results showed that ethyl acetate extract of peony seed coat could reduce cell proliferation rate and the protein levels of PCNA, Bcl-2, p-STAT3, Survivin and the expression level of miR-424-3p (P&lt;0.05), increase apoptosis rate and the protein level of Bax (P&lt;0.05). After transfection with anti-miR-424-3p, the cell proliferation rate, the protein levels of PCNA and Bcl-2 were significantly reduced (P&lt;0.05), the apoptosis rate and the protein level of Bax were significantly increased (P&lt;0.05), while the effect of miR-424-3p mimics was the opposite. Transfection of miR-424-3p mimics could significantly reduce the regulatory effect of ethyl acetate extract of peony seed coat on CAL27 cell proliferation, apoptosis and STAT3/Survivin pathway. It concluded that ethyl acetate extract of peony seed coat could inhibit the activation of the STAT3/Survivin signaling pathway by down-regulating the expression of miR-424-3p, thereby inhibiting the proliferation of oral squamous carcinoma cells and inducing apoptosis.

Kynurenine 3-monooxygenase (KMO), and signal transducer and activator of transcription 3 (STAT3) expression is involved in tumour proliferation and predicts poor survival in canine melanoma.

Canine melanoma is a malignant tumour that exhibits aggressive behaviour, and frequently metastasizes to regional lymph nodes and distant sites. Currently, there are no effective treatments or practical prognostic biomarkers for canine melanoma. The enzyme kynurenine 3-monooxygenase (KMO), which plays a central role in the tryptophan metabolism, has previously been identified as the main pathogenic factor in neurodegenerative diseases; however, it has recently been found to be positively associated with tumour malignancy in human hepatocellular carcinoma and canine mammary tumours. Signal transducer and activator of transcription 3 (STAT3) is a well-known oncoprotein contributing to the proliferation, survival, invasiveness and metastasis of a variety of cancers. Although whether STAT3 and KMO collaborate in tumorigenesis needs to be further verified, our previous findings showed that inhibition of KMO activity reduced activation of STAT3. This study investigated the expressions of KMO and STAT3/phosphorylated (pSTAT3) by immunohistochemical analysis in 85 cases of canine melanoma, showing their expression levels were high within highly mitotic melanoma cells. KMO Overexpression was significantly associated with increased STAT3 and pSTAT3 expressions. Melanoma tissues with higher KMO, STAT3 and pSTAT3 protein expressions were correlated with reduced survival rates of the canine patients. Moreover, inhibition of KMO activity in canine melanoma cells resulted in reduced cell viability, in addition to decreased expressions of STAT3 and pSTAT3. Our results indicated the significance of KMO and the potential role of KMO/STAT3 interaction in enhancing tumour development. Additionally, KMO and STAT3/pSTAT3 may be viewed as useful biomarkers for the prediction of prognosis of canine melanoma.

Potential Repressive Impact of microRNA-20a on Renal Tubular Damage in Diabetic Kidney Disease by Targeting C-X-C Motif Chemokine Ligand 6

C-X-C Motif Chemokine Ligand 6 (CXCL6) is an important chemokine. We attempt in this investigation to explore its role and possible mechanism in diabetic kidney disease (DKD). By intergrating GEO data, CXCL6 expression in DKD patients and normal controls was exhibited. miRWalk website and luciferase reporter assay were used to predict and verify the upstream miRNA of CXCL6. CCK-8 assay and flow cytometry were performed to detect proliferation and apoptosis capacities. The levels of inflammatory key factors (TNF-α, IL-6 and IL-8) were measured using ELISA analysis. Expression of CXCL6, miR-20a, and JAK/STAT3 pathway-related markers were detected by qRT-PCR or western blot assays. CXCL6 was increased in DKD. miR-20a was identified as an upstream regulatory miRNA of CXCL6, and its expression was decreased in DKD and HG-treated HK-2cells. miR-20a overexpression facilitated the proliferation of HG-treated HK-2cells, whereas miR-20a depletion exhibited the opposite phenomenon. The levels of TNF-α, IL-6 and IL-8 were increased by HG treatment in HK-2cells. CXCL6 antagonized the promoting impacts of miR-20a mimics on HG-exposed HK-2cell proliferation. The suppressive effect of miR-20a overexpression on apoptosis and inflammatory response of HG-induced HK-2cell was rescued by CXCL6 enhancement. The protein expression of p-JAK and p-STAT3 were reduced by miR-20a mimic while facilitated by CXCL6 overexpression in HG-stimulated HK-2cells. These consequences hinted that miR-20a might exert a repressive impact on DKD, possibly through targeting CXCL6 and mediating JAK/STAT3 pathway, which offer new targets for DKD treatment.

Effect of matrine on JAK2/STAT3 signaling pathway and brain protection in rats with cerebral ischemia-reperfusion.

Ischemic encephalopathy is a common clinical disease. The main treatment goal is to achieve vascular recanalization. However, after vascular recanalization, the reperfusion of fresh blood can change local cell metabolism, thus adversely affecting cell structure and function, which can result in reperfusion injury. To explore the effect of matrine intervention of different concentrations on JAK2/STAT3 signaling pathway and brain protection in rats with cerebral ischemia-reperfusion. Healthy male Sprague Dawley rats were divided into a blank control group (20 rats), a model group (80 rats) and a sham group (20 rats). In the model group, the middle cerebral artery was occluded with suture method to establish cerebral ischemia-reperfusion model rats, which were subdivided into cerebral ischemia-reperfusion group, and 5, 10 and 20 mg/kg matrine groups, with 20 rats in each group. Indicators including neurological function score, brain infarct size, brain water content, lactic dehydrogenase activity, protein expressions of p-JAK2 and p-STAT3, as well as superoxide dismutase activity and malondialdehyde content were evaluated. Compared with cerebral ischemia-reperfusion group, all the indicators were significantly improved in the 3 matrine treatment groups in a dose-dependent manner, and protein expressions of p-JAK2 and p-STAT3 in the brain tissue and brain cell apoptosis rate were decreased with the increase of matrine concentration (all p < 0.05). Matrine can significantly ameliorate the neurological function and brain edema of rats with cerebral ischemia-reperfusion, and improve superoxide dismutase, malondialdehyde and lactic dehydrogenase levels in the brain tissue and brain cell apoptosis rate. The mechanism of matrine may be related to the inhibition of abnormal JAK2/STAT3 signaling pathway activation.

JLX001 improves myocardial ischemia-reperfusion injury by activating Jak2-Stat3 pathway

AimsTo investigate the preclinical pharmacodynamics and mechanism of JLX001 against myocardial ischemia reperfusion (MI/R) for clinical application. Materials and methodsIn vivo, SD rats were given intragastric administration for 5 days, and the MI/R model was established by ligating/releasing the left anterior descending coronary artery. In vitro, the oxygen-glucose deprivation/reperfusion (OGD/R) model was established after the drug was pre-incubated for 24 h in H9C2 cells. The infract size was determined by TTC staining. Left ventricular function of MI/R rats was detected by echocardiography. The level of histopathological score was determined by hematoxylin-eosin (HE) staining. The level of superoxide dismutase (SOD), malondialdehyde (MDA), creatine kinase (CK), lactic dehydrogenase (LDH), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) were determined by relevant kits. The level of apoptosis was measured by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and Hoechst staining. The expression of p-Jak2, p-Stat3, Bax, Bcl-2, TNF-α, IL-1β protein were determined by western blot. Key findingsJLX001 can significantly improve left ventricular function, reduce myocardial infract size, histopathological score, the level of MDA, CK, LDH, TNF-α, IL-1β and the expression of Bax protein, significantly increase the activity of SOD, Bcl-2 protein expression, p-Jak2 protein expression, p-Stat3 protein expression in rat heart tissues and H9C2 cells. These effects can be reversed by AG490 which is a specific inhibitor of Jak2-Stat3 pathway. SignificanceJLX001 can alleviate MI/R injury by inhibiting myocardial apoptosis, inflammation, and oxidative stress via Jak2-Stat3 pathway in vivo and in vitro.

MicroRNA-124 Overexpression in Schwann Cells Promotes Schwann Cell-Astrocyte Integration and Inhibits Glial Scar Formation Ability.

Schwann cell (SC) transplantation is a promising approach for the treatment of spinal cord injury (SCI); however, SC grafts show a low migratory capacity within the astrocytic environment, which inevitably hampers their therapeutic efficacy. The purpose of this study was to explore mechanisms to modify the characteristics of SCs and astrocytes (ASs), as well as to adjust the SC-AS interface to break the SC-AS boundary, thus improving the benefits of SCI treatment. We observed that the expression levels of miR-124 in SCs and ASs were significantly lower than those in the normal spinal cord. Furthermore, overexpressing miR-124 in SCs (miR-124-SCs) significantly inhibited gene and protein expression levels of SC-specific markers, such as GFAP and Krox20. The expression of neurotrophic factors, Bdnf and Nt-3, was up-regulated in miR-124-SCs without affecting their proliferation. Further, the boundary assay showed an increased number of miR-124-SCs that had actively migrated and entered the astrocytic region to intermingle with ASs, compared with normal SCs. In addition, although Krox20 protein expression was down-regulated in miR-124-SCs, the luciferase assay showed that Krox20 is not a direct target of miR-124. RNA sequencing of miR-124-SCs revealed seven upregulated and eleven downregulated genes involved in cell migration and motility. Based on KEGG pathway and KOG functional analyses, changes in these genes corresponded to the activation of Hippo, FoxO, and TGF-beta signaling pathways, cytokine-cytokine receptor interactions, and the cell cycle. Finally, co-culturing of miR-124-SCs and ASs in a transwell system revealed that GFAP and p-STAT3 protein expression in ASs was significantly reduced. Collectively, these results show that overexpression of miR-124 in SCs promotes SC-AS integration in vitro and may attenuate the capacity of ASs to form glial scars. Thus, this study provides novel insights into modifying SCs by overexpressing miR-124 to improve their therapeutic potential in SCI.

Melatonin relieves sepsis-induced myocardial injury via regulating JAK2/STAT3 signaling pathway.

To study the effect of melatonin on myocardial injury of septic rats through regulating the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway. Healthy rats were selected as the samples and divided into blank group, sepsis group and sepsis + melatonin group. The difference in the myocardial tissue structure in the three groups of rats was observed via hematoxylin-eosin (HE) staining, and the messenger ribonucleic acid (mRNA) expression levels of JAK2 and STAT3 in myocardium were compared among groups through fluorescence quantitative polymerase chain reaction (qPCR). Western blotting was applied to detect the protein expressions of JAK2, phosphorylated (p)-JAK2, STAT3 and p-STAT3, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining was utilized to determine the cell apoptosis in myocardial tissues. Moreover, the activity of superoxide dismutase (SOD) and content of malondialdehyde (MDA) in myocardial tissues as well as the activity of serum creatine kinase (CK) and lactate dehydrogenase (LDH) were measured and compared. There were inflammatory cells in the myocardium in sepsis group, and the pathological changes were milder in sepsis + melatonin group. The mRNA expressions of JAK2 and STAT3 and the protein expressions of JAK2, STAT3, p-JAK2 and p-STAT3 were raised remarkably in sepsis group compared with those in blank group and sepsis + melatonin group. The apoptosis rate in tissues was significantly different among the three groups, and it was the highest in sepsis group, followed by that in sepsis + melatonin group and blank group. There were significant differences in SOD activity and MDA content in myocardial tissues among the three groups, of which the SOD activity was the strongest in blank group, followed by that in sepsis + melatonin group and sepsis group, and the MDA content was the highest in sepsis group, followed by that in sepsis + melatonin group and blank group. Sepsis group had extremely notably increased activity of CK and LDH compared with blank group, while sepsis + melatonin group exhibited evidently decreased activity of CK and LDH in comparison with sepsis group. The JAK2/STAT3 signaling pathway is associated with sepsis-induced myocardial injury, and melatonin can relieve sepsis-induced myocardial injury by regulating the JAK2/STAT3 signaling pathway.

Effect of moxibustion on IL-6/STAT3 signaling in frontal cortex of fatigue rats

To observe the effect of moxibustion on interleukin-6(IL-6)/signal transduction and transcriptional activator 3(STAT3) signaling pathway in the frontal cortex of fatigue rats, so as to reveal its mechanisms underlying alleviation of fatigue. Twenty-one male SD rats were randomly divided into normal control, model, and moxibustion groups (n＝7 rats in each group). The fatigue model was established by forcing the rats to have an exhausted swim under load condition, once daily for 21 days. Moxibustion was applied to bilateral "Zusanli"(ST36) for about 15 min, once every other day for 21 days. The level of IL-6 in the frontal cortex was detected by ELISA, and the expression of Janus kinase 2 (JAK2), phosphorylated JAK2 (p-JAK2), signal transduction and transcriptional activator 3(STAT3) and phosphorylated STAT3 (p-STAT3) proteins in the frontal cortex was detected by Western blot. After modeling, the levels of IL-6 content and p-STAT3 protein expression and ratio of p-STAT3/STAT3 were significantly increased in the model group relevant to the normal control group (P<0.01). Follo-wing moxibustion, the duration of load swimming on the 21st day was significantly prolonged (P<0.01), content of IL-6 and levels of p-STAT3 protein expression and ratio of p-STAT3/STAT3 were significantly down-regulated in the moxibustion group compared with the model group (P<0.05). No significant differences were found between the model and control, and between moxibustion and model groups in the expression levels of JAK2, p-JAK2, STAT3 and p-JAK2/JAK2 (P>0.05). Moxibustion intervention can relieve fatigue in fatigue rats, which is associated with its function in inhibiting IL-6/STAT3 signaling pathway to reduce inflammatory injury.

MiR-181a reduces radiosensitivity of non-small-cell lung cancer via inhibiting PTEN.

The aim of this study is to explore the effect of micro ribonucleic acid (miR)-181a on the radiosensitivity of non-small cell lung cancer (NSCLC) and its potential mechanism of action. The differentially expressed miRNAs were screened in lung cancer tissues of radiotherapy-resistant and non-radiotherapy-resistant NSCLC patients, and verified via reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Next, the effects of different miRNA expressions on patients' survival time were discussed, and target genes of miR-181a were predicted. The effect of miR-181a expression on radiosensitivity was determined using cell counting kit-8 (CCK-8) assay and flow cytometry. The direct target of miR-181a was verified via luciferase reporter assay. Phosphatase and tensin homolog deleted on chromosome ten (PTEN) was overexpressed using lentiviruses, and then whether miR-181a reduces radiosensitivity via targeting PTEN was detected via CCK-8 assay and flow cytometry. Finally, Western blotting was performed to detect the protein expression of PTEN. The screening results of microarray expression profile assay revealed that 15 miRNAs had significant differences in lung cancer tissues of radiotherapy-resistant NSCLC patients compared with those in non-radiotherapy-resistant NSCLC patients. The results of RT-qPCR showed that hsa-miR-181a, hsa-miR-199b, hsa-miR-489 and hsa-miR-589 were significantly up-regulated in the lung cancer tissues of radiotherapy-resistant NSCLC patients compared with those in non-radiotherapy-resistant NSCLC patients. In addition, it was found that the survival time of NSCLC patients was obviously prolonged in hsa-miR-181a low-expression group and hsa-miR-589 high-expression group, but hsa-miR-489 and hsa-miR-199b had no significant influence on the survival time of NSCLC patients. According to KEGG enrichment analysis, the target genes of miR-181a were evidently enriched in the phosphatidylinositol 3-hydroxy kinase (PI3K)/protein kinase B (AKT) signaling pathway, NSCLC signaling pathway and other cancer signaling pathways. Under the radiation dose of 2, 4, 6 and 8 Gy, the survival rate of A549 cells rose in miR-181a mimic group, but declined in miR-181a inhibitor group. Moreover, compared with that in model group, the radiotherapy-induced apoptosis was markedly inhibited in miR-181a mimic group, but markedly promoted in miR-181a inhibitor group. It was also observed that the response of cells to radiotherapy-induced apoptosis was remarkably weakened in miR-181a mimic + PTEN overexpression group compared with that in miR-181a mimic group. Finally, miR-181a mimic group had a significantly lower protein expression of PTEN and significantly higher protein expressions of CXC chemokine receptor 4 (CXCR4), phosphorylated signal transducer and activator of transcription 3 (p-STAT3), p-AKT1 and p-mammalian target of rapamycin (mTOR) than model group, while miR-181a inhibitor group had the opposite protein expressions. The protein expressions of CXCR4, p-STAT3, p-AKT1 and p-mTOR were obviously lower in miR-181a mimic + PTEN overexpression group than those in miR-181a mimic group. MiR-181a reduces the radiosensitivity of NSCLC via inhibiting PTEN expression.

The IL-6/STAT3 signaling pathway mediated by radiotherapy regulates the expression of PD-L1 and affects the biological functions of esophageal cancer cells.

e16531 Background: The mechanism by which radiotherapy regulates PD-L1 expression and affects the biological behavior of esophageal cancer cells is not clear.The IL-6 /STAT3 signaling pathway may be involved. Methods: After irradiation of different doses to the esophageal cancer cell lines (Eca109, KYSE150, and TE1), RT-PCR and Western blotting were used to detect PD-L1, STAT3 and P-STAT3, ELISA was performed to examine the effects on IL-6, CCK-8 assays were used to test the effects on the proliferation. After the optimal dose radiation, Transwell assays were used to detect the invasion and proliferation of cell clones, and cell cycle changes were detected by flow cytometry. Results: The mRNA and the protein expression of PD-L1 in the cancer cell lines was significantly higher than in the normal esophageal cell line HET-1A(P &lt; 0.01). The PD-L1 mRNA levels first increased and then decreased, which peaked 12 hours after 3,6,9,12Gy irradiation and was significantly higher than in nonirradiated cells (P &lt; 0.05). PD-L1 protein expression first increased and then decreased, which peaked 48 hours after 6 Gy irradiation (P &lt; 0.05). P-STAT3 protein expression first increased and then decreased after 6Gy irradiation (P &lt; 0.05), that the expression in Eca109 peaked 48 hours but in KYSE150 and TE1 peaked 24 hours (P &lt; 0.05). IL-6 protein expression peaked 12 hours and decreased gradually after irradiation (P &lt; 0.05). The proliferation levels of the the cancer cell lines decreased after irradiation, and the inhibitory force increased with the increase in dose and time after radiotherapy (P &lt; 0.05). The clone formation ability of the cancer cell lines was inhibited to varying degrees 14 days after irradiation with 6 Gy(P &lt; 0.05). After 48 hours irradiation with 6 Gy, and the invasion ability of the cancer cell lines was lower than that of the nonirradiated cell lines (P &lt; 0.05), and the proportion of cells in G2/M phase was higher in exposed cells than in nonexposed cells (P &lt; 0.05), while the proportion of cells in S phase did not change significantly. Conclusions: PD-L1, IL-6 and STAT3 protein expression in the esophageal cancer cell lines first increased and then decreased consistency after irradiation, radiotherapy could regulate PD-L1 expression through the IL-6/STAT3 signaling pathway and affect the biological functions of esophageal cancer.

Edaravone attenuates myocyte apoptosis through the JAK2/STAT3 pathway in acute myocardial infarction

Basic and clinical studies have demonstrated that the free radical scavenger edaravone has cytoprotective effects on acute myocardial infarction (AMI) but the underlying mechanism is not fully understood. The aim of this research is to explore the effect of edaravone on the apoptotic process involving the JAK2/STAT3 signaling pathway. AMI in rats was established by left anterior descending coronary artery ligation. Two hours after AMI model established rats were treated with edaravone, edaravone plus AG490, physiological saline, respectively. We detected antioxidant effects by reduced glutathione (GSH), glutathione S-transferase (GST), and Glutathione Peroxidase (GSHPx) Activity. The expressions of t-JAK2, p-JAK2, t-STAT3, p-STAT3 and cleaved caspase-3 were examined by western blot. The mRNA levels for Bcl-2, Bax, Fas, and FasL were measured by RT-PCR and apoptosis was assessed by TUNEL. Edaravone significantly improved hemodynamics after AMI (p < 0.05) and reduced the total infarct volumes (p < 0.05). Compared with Sham rats, the mRNA of Bax, Fas, and FasL increased in different degrees in the AMI group, however, the mRNA of Bcl-2 and the ratio of Bcl-2/Bax decreased, especially the myocardial apoptosis index significantly increased in AMI hearts (all p < 0.05). After treatment with edaravone, the mRNA levels of Bcl-2 and the ratio of Bcl-2/Bax significantly upregulated whereas Bax, Fas, FasL apparently decreased, and the protein expressions of p-JAK2 and p-STAT3 dramatically increased (p < 0.05). In addition, cotreatment with JAK2 inhibitor AG490 abolished the effects of edaravone. We conclude that edaravone attenuated myocardial apoptosis induced by AMI via JAK2/STAT3 signaling pathway.

Evaluation of chidamide and PFI-1 as a combination therapy for triple-negative breast cancer

Purpose: To evaluate the in vitro and in vivo effects of the combination therapy of histone deacetylases (HDAsC) inhibitor, chidamide, and bromodomain-containing proteins (BETs) inhibitor, PFI-1, on triplenegative breast cancer (TNBC).&#x0D; Methods: Four distinct breast cancer cell lines and one TNBC mouse model were treated with vehicle, chidamide, PFI-1 alone, or chidamide and PFI-1. The inhibitory effect of chidamide or PFI-1 on HDACs and BETs was assessed by HDAC enzyme inhibition and AlphaScreen assays. Cell viability was determined by MTT assay while protein expression of p-STAT3 was evaluated by western blotting and immunohistochemistry (IHC) staining assay.&#x0D; Results: Chidamide exerted inhibitory effect on HDACs while PFI-1 inhibited BET proteins. The threedimensional model demonstrated the interactions between chidamide and HDAC2, and between PFI-1 and BRD4. Chidamide or PFI-1 exerted inhibitory effects on breast cancer cell proliferation in vitro. However, the combination of PFI-1 and chidamide significantly inhibit MDA-MB-231 cell viability, and decrease the expression of p-STAT3, when compared to that treated with chidamide or PFI-1 alone. Moreover, the combined inhibitory effect of PFI-1 and chidamide on tumor growth was also found in the in vivo mice experiments.&#x0D; Conclusion: The combination of chidamide and PFI-1 is a potential is a potential therapeutic strategy for the management of TNBC.&#x0D; Keywords: Triple-negative breast cancer, Histone deacetylases, Bromodomain

The JAK2/STAT3 pathway is involved in dexmedetomidine-induced myocardial protection in rats undergoing cardiopulmonary bypass.

BackgroundMany studies have reported that dexmedetomidine protects organs from ischemia/reperfusion-induced injury. However, the mechanism of this protective effect remains inconclusive.MethodsRats were randomly divided into 6 groups (n=8). Rats in the sham group were not subjected to cardiopulmonary bypass (CPB) while rats in the other groups underwent CPB for 2 h. Groups L and H received a low and a high dose of dexmedetomidine, respectively. Rats in group AG490 received 10 mg/kg of the Janus kinase 2 (JAK2) inhibitor, AG490, 30 min before anesthesia. Plasma levels of the inflammatory cytokines, interleukin (IL)-6 and IL-10, were measured by enzyme-linked immunosorbent (ELISA), and the apoptosis rate of myocardial cells, the expression of JAK2 and signal transducer and activator of transcription (STAT)3 mRNA, and the protein expression of JAK2, STAT3, pJAK2, pSTAT3, and caspase-3 were analyzed in myocardial tissues by real-time quantitative polymerase chain reaction (qRT-PCR), western blotting, and immunohistochemistry.ResultsWe observed that, in both group L and group H, the level of IL-6 decreased (P<0.05), and the apoptosis rate of myocardial cells were reduced (P<0.05) compared to those in the CPB group. Moreover, qRT-PCR results revealed that dexmedetomidine administration reduced the expression of JAK2 and STAT3 mRNA (P<0.05); pJAK2 and pSTAT3 (P<0.05) protein levels were also reduced as assessed by western blotting and immunohistochemistry (P<0.05).ConclusionsDexmedetomidine treatment reduced CPB-related myocardial injury by inhibiting inflammatory reactions and myocardial apoptosis, and can be a potential therapy in CPB-related surgery.

β-Glucan augments IL-1β production by activating the JAK2/STAT3 pathway in cultured rabbit keratinocytes

Trichophyton mentagrophytes (T. mentagrophytes) is the main cause of rabbit dermatophytosis. As the main pathogen-associated molecular pattern of T. mentagrophytes, the role of β-glucan in the pathogenesis of rabbit dermatophytosis remains elusive. Keratinocytes (KC) are the main cellular component and the first defensive line against fungal pathogens in the skin. Therefore, the present study investigated the effects of β-glucan on rabbit KC from dorsal skin. β-glucan was found to inhibit KC proliferation by 10% at 20 ug/ml and this concentration was thus considered as optimal. Next, 20 ug/ml β-glucan stimulation for 24 h significantly increased CXCL8, CXCL11, and IL-1β secretions in KC. Furthermore, β-glucan exposure induced the expressions of JAK2 mRNA, STAT3 mRNA, and p-STAT3 protein. Silencing JAK2 expression inhibited p-STAT3 protein expression and β-glucan-induced IL-1β secretion. And overexpression of JAK2 further promoted β-glucan-mediated p-STAT3 protein and IL-1β productions. These results suggested that β-glucan-induced CXCL8, CXCL11, and IL-1β secretions in rabbit KC might be involved in the inflammatory response of T. mentagrophytes infected rabbit dorsal skin. However, only IL-1β secretion was promoted by the JAK2/STAT3 signaling pathway. In conclusion, this study is a necessary step toward elucidating the mechanisms that underlie skin immune system injury stimulated by β-glucan.

Heat Shock Protein 70 Protects the Heart from Ischemia/Reperfusion Injury through Inhibition of p38 MAPK Signaling.

Background Heat shock protein 70 (Hsp70) has been shown to exert cardioprotection. Intracellular calcium ([Ca2+]i) overload induced by p38 mitogen-activated protein kinase (p38 MAPK) activation contributes to cardiac ischemia/reperfusion (I/R) injury. However, whether Hsp70 interacts with p38 MAPK signaling is unclear. Therefore, this study investigated the regulation of p38 MAPK by Hsp70 in I/R-induced cardiac injury. Methods Neonatal rat cardiomyocytes were subjected to oxygen-glucose deprivation for 6 h followed by 2 h reoxygenation (OGD/R), and rats underwent left anterior artery ligation for 30 min followed by 30 min of reperfusion. The p38 MAPK inhibitor (SB203580), Hsp70 inhibitor (Quercetin), and Hsp70 short hairpin RNA (shRNA) were used prior to OGD/R or I/R. Cell viability, lactate dehydrogenase (LDH) release, serum cardiac troponin I (cTnI), [Ca2+]i levels, cell apoptosis, myocardial infarct size, mRNA level of IL-1β and IL-6, and protein expression of Hsp70, phosphorylated p38 MAPK (p-p38 MAPK), sarcoplasmic/endoplasmic reticulum Ca2+-ATPase2 (SERCA2), phosphorylated signal transducer and activator of transcription3 (p-STAT3), and cleaved caspase3 were assessed. Results Pretreatment with a p38 MAPK inhibitor, SB203580, significantly attenuated OGD/R-induced cell injury or I/R-induced myocardial injury, as evidenced by improved cell viability and lower LDH release, resulted in lower serum cTnI and myocardial infarct size, alleviation of [Ca2+]i overload and cell apoptosis, inhibition of IL-1β and IL-6, and modulation of protein expressions of p-p38 MAPK, SERCA2, p-STAT3, and cleaved-caspase3. Knockdown of Hsp70 by shRNA exacerbated OGD/R-induced cell injury, which was effectively abolished by SB203580. Moreover, inhibition of Hsp70 by quercetin enhanced I/R-induced myocardial injury, while SB203580 pretreatment reversed the harmful effects caused by quercetin. Conclusions Inhibition of Hsp70 aggravates [Ca2+]i overload, inflammation, and apoptosis through regulating p38 MAPK signaling during cardiac I/R injury, which may help provide novel insight into cardioprotective strategies.