Endoplasmic reticulum stress promoted acinar cell necroptosis in acute pancreatitis through cathepsinB-mediated AP-1 activation.

Acinar cell death and inflammatory response are two important events which determine the severity of acute pancreatitis (AP). Endoplasmic reticulum (ER) stress and necroptosis are involved in this process, but the relationships between them remain unknown. Here, we analyzed the interaction between ER stress and necroptosis and the underlying mechanisms during AP. Experimental pancreatitis was induced in Balb/C mice by caerulein (Cae) and lipopolysaccharide (LPS) or L-arginine (L-Arg) in vivo, and pancreatic acinar cells were also used to follow cellular mechanisms during cholecystokinin (CCK) stimulation in vitro. AP severity was assessed by serum amylase, lipase levels and histological examination. Changes in ER stress, trypsinogen activation and necroptosis levels were analyzed by western blotting, enzyme-linked immunosorbent assay (ELISA), adenosine triphosphate (ATP) analysis or lactate dehydrogenase (LDH) assay. The protein kinase C (PKC)α -mitogen-activated protein kinase (MAPK) -cJun pathway and cathepsin B (CTSB) activation were evaluated by western blotting. Activating protein 1 (AP-1) binding activity was detected by electrophoretic mobility shift assay (EMSA). We found that ER stress is initiated before necroptosis in CCK-stimulated acinar cells in vitro. Inhibition of ER stress by 4-phenylbutyrate (4-PBA) can significantly alleviate AP severity both in two AP models in vivo. 4-PBA markedly inhibited ER stress and necroptosis of pancreatic acinar cells both in vitro and in vivo. Mechanistically, we found that 4-PBA significantly reduced CTSB maturation and PKCα-JNK-cJun pathway -mediated AP-1 activation during AP. Besides, CTSB inhibitor CA074Me markedly blocked PKCα-JNK-cJun pathway -mediated AP-1 activation and necroptosis in AP. However, pharmacologic inhibition of trypsin activity with benzamidine hydrochloride had no effect on PKCα-JNK-cJun pathway and necroptosis in CCK-stimulated pancreatic acinar cells. Furthermore, SR11302, the inhibitor of AP-1, significantly lowered tumor necrosis factor (TNF) α levels, and its subsequent receptor interacting protein kinases (RIP)3 and phosphorylated mixed lineagekinase domain-like (pMLKL) levels, ATP depletion and LDH release rate in CCK-stimulated pancreatic acinar cells. To sum up, all the results indicated that during AP, ER stress promoted pancreatic acinar cell necroptosis through CTSB maturation, thus induced AP-1 activation and TNFα secretion via PKCα-JNK-cJun pathway, not related with trypsin activity. These findings provided potential therapeutic target and treatment strategies for AP or other cell death-related diseases.

Development and validation of a cancer-associated fibroblast-derived lncRNA signature for predicting clinical outcomes in colorectal cancer.

Cancer-associated fibroblasts (CAFs) are actively involved in cancer progression through generating extracellular matrix and orchestrating the crosstalk within the tumor microenvironment (TME). This study aimed to develop and validate a CAF-derived lncRNA (long non-coding RNA) (CAFDL) signature for predicting clinical outcomes in colorectal cancer (CRC). Clinical data and transcriptomic profiles of 2,320 patients with CRC from The Cancer Genome Atlas (TCGA)-COAD and TCGA-READ datasets and 16 Gene Expression Omnibus datasets were included in this study. CAFDLs were identified using weighted gene co-expression network analysis. The CAFDL signature was constructed using the least absolute shrinkage and selection operator analysis in the TCGA-CRC training set. Multiple CRC cohorts and pan-cancer cohorts were used to validated the CAFDL signature. Patients with high CAFDL scores had significantly worse overall survival and disease-free survival than patients with low CAFDL scores in all CRC cohorts. In addition, non-responders to fluorouracil, leucovorin, and oxaliplatin (FOLFOX)/fluorouracil, leucovorin, and irinotecan (FOLFIRI) chemotherapy, chemoradiotherapy, bevacizumab, and immune checkpoint inhibitors had significantly higher CAFDL scores compared with responders. Pan-cancer analysis showed that CAFDL had prognostic predictive power in multiple cancers such as lung adenocarcinoma, breast invasive carcinoma, stomach adenocarcinoma, and thyroid carcinoma. The CAFDL signature was positively correlated with transforming growth factor-beta (TGF-ß) signaling, epithelial-mesenchymal transition, and angiogenesis pathways but negatively correlated with the expression of immune checkpoints such as PDCD1, CD274, and CTLA4. The CAFDL signature reflects CAF properties from a lncRNA perspective and effectively predicts clinical outcomes in CRC and across pan-cancer. The CAFDL signature can serve as a useful tool for risk stratification and provide new insights into the underlying mechanisms of CAFs in cancer immunity.

Immunologic Gene Sets Reveal Features of the Tumor Immune Microenvironment and Predict Prognosis and Immunotherapy Response: A Pan-Cancer Analysis.

In the treatment of cancer, anti-programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) immunotherapy has achieved unprecedented clinical success. However, the significant response to these therapies is limited to a small number of patients. This study aimed to predict immunotherapy response and prognosis using immunologic gene sets (IGSs). The enrichment scores of 4,872 IGSs in 348 patients with metastatic urothelial cancer treated with anti-PD-L1 therapy were computed using gene set variation analysis (GSVA). An IGS-based classification (IGSC) was constructed using a nonnegative matrix factorization (NMF) approach. An IGS-based risk prediction model (RPM) was developed using the least absolute shrinkage and selection operator (LASSO) method. The IMvigor210 cohort was divided into three distinct subtypes, among which subtype 2 had the best prognosis and the highest immunotherapy response rate. Subtype 2 also had significantly higher PD-L1 expression, a higher proportion of the immune-inflamed phenotype, and a higher tumor mutational burden (TMB). An RPM was constructed using four gene sets, and it could effectively predict prognosis and immunotherapy response in patients receiving anti-PD-L1 immunotherapy. Pan-cancer analyses also demonstrated that the RPM was capable of accurate risk stratification across multiple cancer types, and RPM score was significantly associated with TMB, microsatellite instability (MSI), CD8+ T-cell infiltration, and the expression of cytokines interferon-γ (IFN-γ), transforming growth factor-ß (TGF-ß) and tumor necrosis factor-α (TNF-α), which are key predictors of immunotherapy response. The IGSC strengthens our understanding of the diverse biological processes in tumor immune microenvironment, and the RPM can be a promising biomarker for predicting the prognosis and response in cancer immunotherapy.

[Development of Novel Guide Device for Cannulated Screws Implantation in Femoral Neck Fracture Surgery].

Cannulated Screw is a common internal fixation for the treatment of femoral neck fractures. However, the traditional implantation method has disadvantages such as inaccuracy and large radiation exposure. Based on the anatomical characteristics of the femoral neck and geometric principles, we develop a novel guide device for cannulated screws insertion. The cadaver experiment showed that it can improve the accuracy of cannulated screws implantation, reduce puncture attempts and the radiation exposure of doctors and patients.

A new technology using a customized 3D printed fixator to assist fracture reduction and fixation: Technical note.

BACKGROUND: Poor reduction can lead to complications such as deformity and delayed fracture healing. We introduce a 3D printed external fixator technology that can assist in fracture reduction and fixation. METHODS: A fractured long bone was first fixed by a temporary external fixator and then scanned with computed tomography. Three-dimensional reconstruction of the contour and bone fragments of the affected limb was performed using Mimics software, and the fracture reduction was simulated. Subsequently, data were imported into SolidWorks software for customized external fixator design and 3D printing. Through the precise assembly of the 3D printed external fixator and external fixation pins, automatic fracture reduction. RESULTS: The patient's fractures were well reduced, firmly fixed, and the postoperative fractures healed well with no complications. CONCLUSION: The technique we introduce not only assists in fracture reduction for temporary external fixation but can also be used as a definitive treatment for long bone fractures.

Comparison of the Kirschner Wire Tension Band with a Novel Nickel-Titanium Arched Shape-Memory Alloy Connector in Transverse Patellar Fractures: A Retrospective Study.

This study aims to compare the clinical outcomes of the nickel-titanium arched shape-memory alloy connector (hereafter referred to as the ASC) and tension band fixation for the treatment of transverse patellar fractures. We retrospectively analyzed a total of 257 patients with transverse patellar fractures who were treated at our emergency orthopaedics department from March 2010 to March 2017. Either an ASC or the Kirschner wire (K-wire) tension band had been used to treat these fractures according to surgeons' experience and preference. We compared operative details, postoperative recovery, and postoperative knee function at 6 months. In terms of surgical duration, blood loss, incision length, length of hospital stay, and postoperative complications, patients in the ASC group showed significantly better results than patients in the K-wire group (p < 0.05). There were no significant differences between the two groups in terms of fracture healing time, knee mobility, and the Boström score at the postoperative 6-month evaluation (p > 0.05). Though, there were similar functional outcomes between two groups whose transverse patellar fractures were different methods, we found that the ASC method was a more reliable, more minimally invasive, and safer treatment option than the tension band wiring method using K-wires, resulting in less tissue damage, shorter surgical duration, shorter length of hospital stay, and fewer complications.

ONECUT2 Accelerates Tumor Proliferation Through Activating ROCK1 Expression in Gastric Cancer.

BACKGROUND: Transcription factors (TFs) are key regulators which control gene expression during cancer initiation and progression. In the current study, we aimed to explore the proliferative function and clinical significance of TFs in gastric cancer (GC). METHODS: Differential analysis was used to investigate the overall expression difference between normal and tumor tissues of each TF in TCGA-STAD cohort. The quantitative real-time polymerase chain reaction (qRT-PCR) was performed to confirm the mRNA expression of one cut homeobox 2 (ONECUT2) in GC tissues. Western blot analysis was conducted to confirm the protein knockdown efficiency. Cell counting, colony formation, and GC xenograft model assays were performed to confirm the proliferative function of ONECUT2 in GC cells. Gene set enrichment analysis (GESA) and qRT-PCR were conducted to confirm the affected signaling pathways and downstream targets of ONECUT2. RESULTS: Our data indicated that a TF named ONECUT2 was highly expressed in GC and correlated with patients' poor prognosis. Importantly, knockdown of ONECUT2 dramatically decreased GC cells proliferation, whereas overexpression of ONECUT2 promoted carcinogenesis in GC. Kyoto encyclopedia of genes and genomes (KEGG) analysis revealed that the upregulating ONECUT2 induced the activation of Wnt signaling pathway and cell cycle regulation pathway. We further identified that ONECUT2 boosted gastric cancer cell proliferation through enhancing ROCK1 (Rho associated coiled-coil containing protein kinase 1) mRNA expression. High level of ROCK1 expression rescued proliferative behavior of ONECUT2-deficient GC cells. CONCLUSION: Our findings demonstrated that ONECUT2 promoted GC cells proliferation through activating ROCK1 expression at the DNA level, suggesting that ONECUT2-ROCK1 axis might be a potential therapeutic target in GC.

PLXNC1 Enhances Carcinogenesis Through Transcriptional Activation of IL6ST in Gastric Cancer.

Background: Transcriptional factors (TFs) are responsible for orchestrating gene transcription during cancer progression. However, their roles in gastric cancer (GC) remain unclear. Methods: We analyzed the differential expressions of TFs and, using GC cells and tissues, investigated plexin C1 (PLXNC1) RNA levels, as well as PLXNC1's clinical relevance and functional mechanisms. The molecular function of PLXNC1 was evaluated in vitro and in vivo. Kaplan-Meier curves and the log-rank test were used to analyze overall survival (OS) and disease-free survival (DFS). Results: PLXNC1 was frequently up-regulated in GC and associated with poor prognosis. The expression level of PLXNC1 could serve as an independent biomarker to predict a patient's overall survival. Notably, knockdown of PLXNC1 significantly abolished GC cell proliferation, and migration, and overexpression of PLXNC1 accelerated carcinogenesis in GC. The gene set enrichment analysis (GSEA) indicated that high-expression of PLXNC1 was positively correlated with the activation of epithelial-mesenchymal transition (EMT), TNF-α, and IL-6/STAT3 signaling pathways. PLXNC1 promoted proliferation and migration of GC cells through transcriptional activation of the interleukin 6 signal transducer (IL6ST), which could rescue the malignant behavior of PLXNC1-deficient GC cells. Conclusions: Our study demonstrated that the PLXNC1 plays an oncogenic role in GC patients. The PLXNC1-IL6ST axis represents a novel potential therapeutic target for GC.

Myeloid-specific dopamine D2 receptor signalling controls inflammation in acute pancreatitis via inhibiting M1 macrophage.

BACKGROUND AND PURPOSE: Macrophage infiltration and activation is a critical step during acute pancreatitis (AP). We have shown that pancreas-specific D2 receptor signalling protects against AP severity. As it is unclear to what extent myeloid-specific D2 receptor mediates AP, we investigated the role of myeloid-specific D2 receptor signalling in AP. EXPERIMENTAL APPROACH: Using wild-type and LysM+/cre D2 fl/fl mice, AP was induced by l-arginine, caerulein and LPS. Murine bone marrow-derived macrophages and human peripheral blood mononuclear cells (PBMCs) were isolated, cultured and then induced to M1 phenotype. AP severity was assessed by measurements of serum amylase and lipase and histological grading. Macrophage phenotype was assessed by flow cytometry and qRT-PCR. NADPH oxidase-induced oxidative stress and NF-κB and NLRP3 inflammasome signalling pathways were also evaluated. KEY RESULTS: We found that dopaminergic system was activated and dopamine reduced inflammatory cytokine expression in M1-polarized macrophages from human PBMCs. Dopaminergic synthesis was also activated, but D2 receptor expression was down-regulated in M1-polarized macrophages from murine bone marrows. During AP, myeloid-specific D2 receptor deletion worsened pancreatic injury, systematic inflammation and promoted macrophages to M1 phenotype. Furthermore, M1 macrophages from LysM+/cre D2 fl/fl mice exhibited increased NADPH oxidase-induced oxidative stress and enhanced NF-κB and NLRP3 inflammasome activation. D2 receptor activation inhibited M1 macrophage polarization, oxidative stress-induced NF-κB and NLRP3 inflammasome activation. CONCLUSION AND IMPLICATIONS: Our data for the first time showed that myeloid-specific D2 receptor signalling controls pancreatic injury and systemic inflammation via inhibiting M1 macrophage, suggesting D2 receptor activation might serve as therapeutic target for AP.

Reactive Oxygen Correlated Chemiluminescent Imaging of a Semiconducting Polymer Nanoplatform for Monitoring Chemodynamic Therapy.

In chemodynamic therapy (CDT), real-time monitoring of reactive oxygen species (ROS) production is critical to reducing the nonspecific damage during CDT and feasibly evaluating the therapeutic response. However, CDT agents that can emit ROS-related signals are rare. Herein, we synthesize a semiconducting polymer nanoplatform (SPN) that can not only produce highly toxic ROS to kill cancer cells but also emit ROS-correlated chemiluminescent signals. Notably, the efficacy of both chemiluminescence and CDT can be significantly enhanced by hemin doping (∼10-fold enhancement for luminescent intensity). Such ROS-dependent chemiluminescence of SPN allows ROS generation within a tumor to be optically monitored during the CDT process. Importantly, SPN establishes an excellent correlation of chemiluminescence intensities with cancer inhibition rates in vitro and in vivo. Thus, our nanoplatform represents the first intelligent strategy that enables chemiluminescence-imaging-monitored CDT, which holds potential in assessing therapeutic responsivity and predicting treatment outcomes in early stages.

Unexpected mechanism of colitis amelioration by artesunate, a natural product from Artemisia annua L.

BACKGROUND: Artemisinin and its derivatives are known to exert immunosuppressive effects through modulating adaptive immunity. We investigated a novel role of artesunate in regulating innate immunity, including both macrophages (MΦ) and dendritic cells (DCs), which are known to involve in DSS-induced colitis. METHODS: Effects of artesunate on innate immunity were extensively evaluated, both in vivo using DSS-colitis model with WT and T cell-deficient RAG mice (RAG-/-) and in vitro using cell culture models, including in-depth analyses of MΦ/DC apoptosis and cytokine expression by flow cytometry, Western blot, or immunohistology. RESULTS: Unexpectedly, artesunate significantly ameliorated the DSS colitis of both WT and RAG1-/- mice with similar potency, suggesting a mechanism that involves primarily innate rather than adaptive immunity. In vivo mechanistic studies revealed that artesunate markedly induced apoptosis of lamina propria MΦs and DCs and suppressed mucosal TNF-α and IL-12p70 in DSS-colitis. In vitro, artesunate potently induced a dose- and time-dependent apoptosis of murine bone marrow-derived DCs and human THP-1 MΦs, through the caspases-9-mediated intrinsic pathway. Artesunate significantly decreased the secretion of IL-12p40/70 by DCs and TNF-α by MΦs. Furthermore, a combination of artesunate with an immunomodulator (methotrexate/triptolide/azathioprine) exhibited superior potency in promoting apoptosis of MΦs than any individual drug alone. CONCLUSIONS: The immunomodulatory mechanism of artesunate in colitis involves a novel and potent induction of the intrinsic apoptosis pathway of proliferating MΦs and DCs and suppression of IL-12 and TNF-α. Artemisinin and its derivatives are promising new therapeutic alternatives for IBD, either alone or in combination with other immunomodulators.

TRIM58 suppresses the tumor growth in gastric cancer by inactivation of ß-catenin signaling via ubiquitination.

Objective: To investigate and define the underlying molecular mechanism of tripartite motif-containing 58 (TRIM58) in regulating the tumor growth of gastric cancer (GC).Methods: TRIM58 expression in GC tissues and cells was detected by real-time PCR and Western blot, followed by lentiviral-induced overexpression or knockdown of TRIM58. Subsequently, CCK8, BrdU-ELISA, flow cytometry, immunoprecipitation, in vitro animal experiments and immunochemistry were performed to explore the function of TRIM58. Western blotting was used to detect ß-catenin, C-myc, Cyclin D1, and survivin expression.Results: TRIM58 expression was significantly reduced in tumor tissues of GC patients and GC cell lines, whereas ß-catenin, C-myc, Cyclin D1, and survivin were highly expressed. Overexpression of TRIM58 in GC cells resulted in decreases in ß-catenin, C-myc, Cyclin D1, and survivin protein expression and significantly suppressed proliferation by preventing cell-cycle progression and promoting cell apoptosis. Conversely, TRIM58 knockdown resulted in the opposite effects. Furthermore, the effect of TRIM58 knockdown on GC cells was potently reversed by a ß-catenin inhibitor, XAV939. Immunoprecipitations showed the interaction between TRIM58 and ß-catenin, and TRIM58 overexpression significantly enhanced ß-catenin degradation. In addition, we found a significant decrease in the growth and weight of tumors and an increase in tumor cell apoptosis in TRIM58-overexpression nude mice, which were also accompanied by reduced ß-catenin expression.Conclusions: These data suggest that TRIM58 may function as a tumor suppressor in GC and potentially suppress the tumor growth of gastric cancer by inactivation of ß-catenin signaling via ubiquitination.

Nickel-titanium arched shape-memory alloy connector combined with bone grafting in the treatment of scaphoid nonunion.

PURPOSE: To summarize the techniques and clinical effectiveness in treating scaphoid nonunion with nickel-titanium (Ni-Ti) arched shape-memory alloy connector in combination with autologous iliac bone grafts. METHODS: This study retrospectively analyzed 18 scaphoid nonunion cases treated with arched connectors with autologous iliac bone grafts. Based on scaphoid nonunion, 2 cases were classified as type II (fibrous union), 4 cases as type III (mild sclerotic union), 6 cases as type IV (moderate resorption and sclerosis), 5 cases as type V (severe bone resorption and sclerosis), and 1 case as type VI (pseudarthrosis formation). At the first 4, 8 and 12 weeks after the surgery, wrist anteroposterior, lateral X-ray were obtained, respectively, to evaluate bone healing. Patients who had not yet reached the standard of healing at 12 weeks after surgery would continue to receive additional appointments for follow-up visits, such as 14 weeks, 16 weeks, 18 weeks after surgery, until their imaging studies had achieved satisfactory bone healing. Clinical effectiveness was evaluated comprehensively, based on bone union time, Mayo wrist score, and visual analog pain score. RESULTS: All 18 patients achieved satisfactory reduction and fixation with a mean union time of 4.2 months. Preoperative Mayo wrist score averaged 57.4 and average final postoperative follow-up was 91.4. On the other hand, mean preoperative VAS score was 6.8, and final postoperative follow-up average was 1.6. Mayo wrist score of the overall treatment effectiveness was excellent (90-100) in 12 cases, good (80-90) in 5 cases, and acceptable (60-80) in 1 case with zero poor (below 60) cases observed. Statistical analysis suggested that a statistically significant improvement in fracture healing, wrist function recovery and visual analog pain after surgery when compared to the scores of the patients before surgery. CONCLUSION: Using Ni-Ti arched shape-memory alloy connector in combination with autologous bone grafting provided a new modality to treat scaphoid nonunions in a less traumatic, convenient to operate and satisfactory manner in treatment outcomes, and thus is worthy of further application.

Homeobox B7 accelerates the cancer progression of gastric carcinoma cells by promoting epithelial-mesenchymal transition (EMT) and activating Src-FAK pathway.

Aim: To study the carcinogenetic mechanism of HOXB7 in gastric cancer (GC) remains. Methods: Two human GC cell lines - SGC7901 and SNU1 - were used for this study. SGC7901 cells were transfected with siRNA-HOXB7 (siHOXB7) to knock down HOXB7 expression, whereas, SNU1 cells were transduced with pCDNA3.1-HOXB7 to overexpress HOXB7. After transfection, cancer progression was assessed by determining cell proliferation, wound-healing process, cell cycle, apoptosis, invasion, and migration. The effect of HOXB7 on epithelial-mesenchymal transition (EMT) was measured by observing changes in F-actin cytoskeleton and evaluating the expression of EMT markers. p-Scr and p-FAK were evaluated to assess the mechanism. Results: Knockdown of HOXB7 suppressed cell proliferation, alleviated the wound-healing process, inhibited cell migration and invasion, and arrested the cell cycle while promoting cell apoptosis, suggesting the tumor-suppressive effect of siHOXB7 in human GC cells. On the contrary, HOXB7 overexpression showed a tumor-promoting effect on human GC cells. Moreover, we confirmed an inhibitory effect of siHOXB7 on the EMT process by preventing epithelial cells from acquiring a mesenchymal phenotype and downregulating mesenchymal markers (vimentin, ß-catenin, N-cadherin, Twist) while upregulating epithelial markers (E-cadherin). Our data revealed that HOXB7 was associated with Src/FAK and favored the activation of the Src-FAK pathway in human GC cells. Conclusion: HOXB7 accelerated the malignancy of GC, by facilitating EMT and regulating the Scr-FAK pathway.

Study protocol of a randomized phase III trial of comparing preoperative chemoradiation with preoperative chemotherapy in patients with locally advanced gastric cancer or esophagogastric junction adenocarcinoma: PREACT.

BACKGROUND: The prognosis of patients with locally advanced gastric cancer or esophagogastric junction adenocarcinoma is still dismal. There are no standard treatment strategies for these patients. Multidisciplinary team (MDT) approach is a good choice for making a high-quality decision. Generally, MDT will recommend these patients to receive preoperative chemotherapy or preoperative chemoradiation based on all kinds of treatment guidelines. However, the preferred preoperative treatment is still not established. In order to solve this problem, we carry out this randomized phase III trial of comparing preoperative chemoradiation with preoperative chemotherapy in patients with locally advanced gastric cancer or esophagogastric junction adenocarcinoma. METHODS: Eligible patients with locally advanced gastric cancer or esophagogastric junction adenocarcinoma are randomized to receive preoperative chemoradiation or preoperative chemotherapy, followed by surgery and postoperative chemotherapy. In the preoperative chemoradiation arm (Pre-CRT), patients receive two cycles of S-1 and oxaliplatin (SOX), chemoradiation, then followed by surgery and three more cycles of SOX chemotherapy. In the preoperative chemotherapy arm (Pre-CT), patients receive three cycles of SOX, following surgery three more cycles of SOX are given. The primary endpoint of this trial is to verify that preoperative chemoradiation could significantly improve the 3-year disease free survival (DFS) of patients with locally advanced gastric cancer or esophagogastric junction adenocarcinoma compared to preoperative chemotherapy. DISCUSSION: The results from this trial will provide important information about whether preoperative chemoradiation could improve survival compared to preoperative chemotherapy among patients with locally advanced gastric cancer or esophagogastric junction adenocarcinoma. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03013010. First posted January 6, 2017.

Commensal Escherichia coli Aggravates Acute Necrotizing Pancreatitis through Targeting of Intestinal Epithelial Cells.

An increase of Escherichia-Shigella was previously reported in acute necrotizing pancreatitis (ANP). We investigated whether Escherichia coli MG1655, an Escherichia commensal organism, increased intestinal injury and aggravated ANP in rats. ANP was induced by retrograde injection of 3.5% sodium taurocholate into the biliopancreatic duct. Using gut microbiota-depleted rats, we demonstrated that gut microbiota was involved in the pancreatic injury and intestinal barrier dysfunction in ANP. Using 16S rRNA gene sequencing and quantitative PCR, we found intestinal dysbiosis and a significant increase of E. coli MG1655 in ANP. Afterward, administration of E. coli MG1655 by gavage to gut microbiota-depleted rats with ANP was performed. We observed that after ANP induction, E. coli MG1655-monocolonized rats presented more severe injury in the pancreas and intestinal barrier function than gut microbiota-depleted rats. Furthermore, Toll-like receptor 4 (TLR4)/MyD88/p38 mitogen-activated protein (MAPK) and endoplasmic reticulum stress (ERS) activation in intestinal epithelial cells were also increased more significantly in the MG1655-monocolonized ANP rats. In vitro, the rat ileal epithelial cell line IEC-18 displayed aggravated tumor necrosis factor alpha-induced inflammation and loss of tight-junction proteins in coculture with E. coli MG1655, as well as TLR4, MyD88, and Bip upregulation. In conclusion, our study shows that commensal E. coli MG1655 increases TLR4/MyD88/p38 MAPK and ERS signaling-induced intestinal epithelial injury and aggravates ANP in rats. Our study also describes the harmful potential of commensal E. coli in ANP.IMPORTANCE This study describes the harmful potential of commensal E. coli in ANP, which has not been demonstrated in previous studies. Our work provides new insights into gut bacterium-ANP cross talk, suggesting that nonpathogenic commensals could also exhibit adverse effects in the context of diseases.

The synergistic therapeutic efficacy of vancomycin and omega-3 fatty acids alleviates Staphylococcus aureus-induced osteomyelitis in rats.

Our study evaluated the synergistic impact of vancomycin and omega-3 fatty acids against osteomyelitis in a Staphylococcus aureus-induced rat model of osteomyelitis. The animals were grouped as follows: sham (group I), osteomyelitis (group II, control), vancomycin (20 mg/kg body weight, group III), omega-3 fatty acids (20 mg/kg body weight, group IV) and vancomycin (20 mg/kg body weight) + omega-3 fatty acids (20 mg/kg body weight) (group V). Lipid peroxidation, superoxide dismutase (SOD), glutathione peroxidase (Gpx), catalase, reduced glutathione (GSH), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were measured. The determination of bacterial growth and histopathological analyses were carried out. The lipid peroxidation, GSH, SOD, catalase and Gpx levels recovered to near-normal levels following combined treatment with vancomycin and omega-3 fatty acids. The TNF-α and IL-6 levels were reduced to near-normal levels. Combined supplementation with vancomycin and omega-3 fatty acids significantly reduced bacterial growth in bone and the implanted wire. Furthermore, the bone infection levels and histopathological score were reduced. In summary, combined treatment with vancomycin and omega-3 fatty acids was effective against bacterial growth and bone infection compared to monotherapy with vancomycin or omega-3 fatty acids.

Iron overload threatens the growth of osteoblast cells via inhibiting the PI3K/AKT/FOXO3a/DUSP14 signaling pathway.

Iron overload is a common stress in the development of cells. Growing evidence has indicated that iron overload is associated with osteoporosis. Therefore, enhancing the understanding of iron overload would benefit the development of novel approaches to the treatment of osteoporosis. The purpose of the present study was to analyze the effect of iron overload on osteoblast cells, via the MC3T3-E1 cell line, and to explore its possible underlying molecular mechanisms. Ferric ammonium citrate (FAC) was utilized to simulate iron overload conditions in vitro. FAC-induced iron overload strongly suppressed proliferation of osteoblast cells and induced apoptosis. Moreover, iron overload strongly suppressed the expression of dual-specificity phosphatase 14 (DUSP14). Additionally, overexpression of DUSP14 protected osteoblast cells from the deleterious effects of iron overload, and this protective effect was mediated by FOXO3a. Additionally, matrine rescued the function of DUSP14 in osteoblast cells. Most importantly, our analysis demonstrated the essential role of the PI3K/AKT/FOXO3a/DUSP14 signaling pathway in the defense against iron overload in osteoblast cells. Overall, our results not only elucidate deleterious effects of iron overload, but also unveil its possible signaling pathway in osteoblast cells.