Th1 promotes M1 polarization of intestinal macrophages to regulate colitis-related mucosal barrier damage

This work aimed to investigate the role of helper T cell 1 (Th1) in chronic colitis and its immunoregulatory mechanism. The proportions of Th1 and Th2, and the levels of related cytokines in tissues from patients with inflammatory bowel disease (IBD; ulcerative colitis+Crohn's disease, UC+CD) were detected. DSS was used to induce the mouse model of IBD; thereafter, Th1 cells were induced in vitro and amplified before they were injected intraperitoneally. Later, the changes in life state and body weight of mice were observed, the proportion of M1 macrophages in mucosal tissues and mucosal barrier damage were detected. After treatment with macrophage scavenging agent (Clodronate Liposomes, CLL), the influence of Th1 on IBD mice was observed. Then, the intestinal macrophages were co-cultured with Th1 in vitro to observe the influence of Th1 on the polarization of intestinal macrophages. Besides, cells were treated with the STAT3 inhibitor to further detect the macrophage polarization level. Intestinal macrophages were later co-cultured with intestinal epithelial cells to observe the degree of epithelial cell injury. The Th1 proportions in intestinal tissues of UC and CD patients were higher than those in healthy subjects, but the difference in Th2 proportion was not significant. In the IBD mouse model, Th1 induced the M1 polarization of macrophages, aggravated the intestinal inflammatory response, and resulted in the increased mucosal barrier permeability. Pretreatment with CLL antagonized the effect of Th1 cells, reduced the intestinal tissue inflammatory response and mucosal barrier permeability.

LncRNA PSCK6-AS1-HIPK2 promotes Th1 differentiation via STAT1 phosphorylation to regulate colitis-related mucosal barrier damage

This work aimed to investigate the role of long non-coding RNA (lncRNA) PCSK6-AS1 in inflammatory bowel disease (IBD). The levels of PCSK6-AS1 in human samples were detected, and its target protein HIPK2 was explored by protein mass spectrometry and ground select test (GST) method. Meanwhile, the HIPK2-STAT1 interaction relation was verified by pull-down assay. In the mouse model, Dextran Sulfate Sodium（DSS） was used to induce mouse colitis, then the effect of PCSK6-AS1 on mouse mucosal barrier was detected by immunohistochemical (IHC) staining, hematoxylin and eosin (H&E) staining, and the proportion of T-helper cells 1（Th1) cells was measured by flow cytometry (FCM). For in-vitro experiments, Th0 cells were used as the objects, and the effect of PCSK6-AS1 on Th1 differentiation was explored by FCM and enzyme-linked immunosorbent assay (ELISA). According to our results, the expression of PCSK6-AS1 in colitis tissues increased. PCSK6-AS1 interacted with HIPK2 to promote the expression of the latter, while HIPK2 promoted STAT1 phosphorylation to regulate Th1 differentiation. Th1 differentiation accelerated the mucosal barrier injury and aggravated the progression of colitis. In the Th0 model, PCSK6-AS1 promoted Th1 differentiation. In the animal model, PCSK6-AS1 enhanced Th1 differentiation in the tissues, decreased the tight junction (TJ) protein levels, and improved the mucosal barrier permeability. Suppressing PCSK6-AS1 and the HIPK2 inhibitor tBID decreased Th1 differentiation and tissue inflammation. According to our results, PCSK6-AS1 promotes Th1 cell differentiation via the HIPK2-STAT1 signaling, thus aggravating the chronic colitis-related mucosal barrier damage and tissue inflammation. PCSK6-AS1 has an important role in the occurrence and development of IBD.

NADPH oxidase 4 regulate the glycolytic metabolic reprogramming of microglial cells to promote M1 polarization

This work aimed to investigate the role and mechanism of NADPH oxidase 4 (NOX4) in the polarization of microglial cells. Microglial cells were transfected with the NOX4 overexpression plasmid (pGL3-NOX4), and later treated with lipopolysaccharide (LPS) and interferon-γ (IFN-γ) to induce its M1 polarization. Later, the F4/80 + CD86 + cell proportion was detected by flow cytometry (FCM), the inflammatory factor expression levels were analyzed through enzyme-linked immunosorbent assay (ELISA), while ionized calcium binding adapter molecule 1 (IBA-1) and PKM2 expression were measured by immunofluorescence (IF) staining. In addition, dichlorodihydrofluorescein diacetate probe was utilized to detect the reactive oxygen species (ROS) levels, glucose uptake, and glycolysis, as well as lactic acid level. The expression of glycolytic enzymes PKM2, HK2, and citrate (Si)-synthas (CS) was detected by Western-blot (WB) assay. Moreover, the polarization level of microglial cells was detected after ROS expression was suppressed by the ROS inhibitor N-acetylcysteine (NAC). In mouse experiments, LPS was applied in inducing central neuroinflammation in NOX4 knockdown mouse model (KO) and wild-type mice (WT). Thereafter, the inflammatory factor levels and lactic acid level in mouse tissues were detected; IBA-1 and CD86 expression in mice was measured by IF staining; and the expression of glycolytic enzymes PKM2, HK2, and CS in the central nervous system (CNS) was also detected. After NOX4 overexpression in microglial cells, the M1 polarization level was upregulated, the F4/80 + CD86 + cell proportion increased, and inflammatory factors were upregulated. At the same time, the expression of glycolytic enzymes PKM2, HK2, and CS was upregulated. NAC pretreatment suppressed the effects of NOX4, reduced the F4/80 + CD86 + cell proportion, and suppressed the expression of PKM2, HK2, and CS. In the mouse model, the expression levels of CD86 in KO group decreased, and the inflammatory factors were also downregulated. NOX4 promotes glycolysis of microglial cells via ROS, thus accelerating M1 polarization and inflammatory factor expression. In this regard, NOX4 is promising as a new target for the treatment of neuroinflammation.

Antrodia Camphorata Polysaccharide activates autophagy and regulates NLRP3 degradation to improve liver injury-related inflammatory response

This study illustrated the liver protection mechanism of ACP from the perspective of autophagy activation. ACP suppressed the inflammatory injury of KCs, and decreased the cell apoptosis rate. After LTG and LC3 staining, ACP promoted lysosomal production, increased LC3 expression, activated autophagy, and suppressed the expression of NLRP3 and inflammatory factors. Under the electron microscope, ACP accelerated the production of autophagosomes. After simultaneous treatment with 3-MA and ACP, the effect of ACP on resisting KC injury decreased, the expression of NLRP3 was up-regulated, and autophagy was suppressed. As discovered in the mouse model of liver injury, ACP inhibited the ALT and AST levels, promoted the occurrence of autophagy, reduced NLRP3 expression and alleviated liver injury. ACP activates autophagy to induce NLRP3 degradation, thus suppressing inflammatory response in liver injury and exerting the liver protection effect, which is one of the mechanisms of action of ACP.

Moronic acid improves intestinal inflammation in mice with chronic colitis by inhibiting intestinal macrophage polarization

This study focuses on exploring the role and mechanism of moronic acid (MOA), a small triterpenoid molecule, against inflammatory bowel disease (IBD). Intestinal macrophages were cultured in vitro, and their M1 polarization was induced by lipopolysaccharide (LPS) and interferon gamma (IFN-γ). After intervention with MOA, the proportion of M1 macrophages was detected, and the levels of inflammatory cytokines (TNF-α, IL-6, and IL-1β) were examined by ELISA. IFA staining was performed to determine the P50 and CD86 expressions, while DCFH-DA was used to determine the reactive oxygen species (ROS) level, as well as the p-P50 and NLRP3 protein levels. Additionally, we also used N-acetylcysteine, a ROS inhibitor, to further explore the association between MOA and ROS-NF-κB signaling. In murine experimentation, colitis was induced in mice with DSS. After MOA intervention, we assessed the mucosal barrier damage, tissue ROS, as well as protein and inflammatory cytokine levels. MOA could inhibit the M1 polarization of intestinal macrophages, suppress the expressions of inflammatory cytokines, and reduce the level of ROS-NF-κB-NLRP3 signaling. After inhibiting ROS through NAC treatment, the effect of MOA was evidently weakened. Clearly, MOA exerted its activity via ROS. In the murine model, MOA could lower the CD86 level in the intestinal tissues, inhibit the M1 polarization of macrophages, and reduce the tissue levels of inflammatory cytokines. This study finds that MOA can regulate ROS-NF-κB-NLRP3 signaling by inhibiting ROS, thereby suppressing the M1 polarization of intestinal macrophages, which plays a protective role in IBD.

NOX4 promotes Kupffer cell inflammatory response via ROS-NLRP3 to aggravate liver inflammatory injury in acute liver injury

AIM

This work aimed to investigate the mechanism of NOX4 in promoting Kupffer cells (KCs) activation and tissue inflammatory response in acute liver injury.

METHODS

Initially, the mouse KCs were cultured in vitro. Thereafter, the NOX4 overexpression plasmid was transfected into KCs to construct the overexpression cell line. Then, KCs inflammatory response was induced by LPS + Nigericin treatment. CCK-8 assay was performed to detect cell viability, flow cytometry (FCM) was conducted to measure cell apoptosis, enzyme-linked immunosorbent assay (ELISA) was performed to detect inflammatory factor levels in the culture medium, NLRP3 and ASC expression in cells was detected by immunofluorescence (IF) staining, and ROS expression was detected by the DCFH-DA probe. Furthermore, the expression levels of NLRP3, ASC and Caspase-1 proteins were detected by Western-Blot (WB) assay. Furthermore, cells were pre-treated with NOX inhibitor or NAC to suppress NOX4 expression or ROS production, aiming to further investigate the effect on KCs inflammatory response. In mouse experiments, the NOX4 knockdown mice and wild-type (WT) mice were adopted for carrying out experiments. The mouse model of ALI was constructed with LPS and D-GalN treatment. Thereafter, the changes in tissue samples were detected by H&E staining, NLRP3 expression was measured by histochemical staining, inflammatory factors in tissues were analyzed by ELISA, and the levels of NLRP3, ASC and Caspase-1 proteins in tissues were detected by WB assay.

RESULTS

LPS induced KCs inflammatory response. NOX4 overexpression decreased the mouse viability and increased the apoptosis rate. The levels of inflammatory factors were up-regulated in the culture medium. In addition, ROS were activated, and the positive cell number increased. Moreover, NOX4 promoted NLRP3 activation and significantly increased the expression of NLRP3 and ASC. Pretreatment with NOX4 inhibitor or NAC antagonized the effects of NOX4 and suppressed the KCs inflammatory response. In the mouse model, NOX4 knockdown significantly suppressed the activation and inflammatory response of microglial cells in tissues, reducing the NLRP3 expression in tissues.

CONCLUSION

NOX4 activates the NLRP3 inflammasome via ROS to promote inflammatory response in KCs and the release of inflammatory factors, suppressing NOX4 can improve ALI in mice, and NOX4 is promising as a new target for ALI treatment.

Antrodia camphorata polysaccharide improves inflammatory response in liver injury via the ROS/TLR4/NF-κB signal

Antrodia Camphorata Polysaccharide (ACP) refers to a kind of polysaccharide extracted from the natural porous fungus Antrodia camphorata. This study investigated the mechanism of action of ACP in protecting the liver. The results showed that ACP suppressed the LPS‐induced KC cell activation, reduced the expression of inflammatory factors, increased the SOD level and suppressed ROS expression. In addition, N‐acetylcysteine (NAC) was adopted for pre‐treatment to suppress ROS. The results indicated that NAC synergistically exerted its effect with ACP, suggesting that ACP played its role through suppressing ROS. Further detection revealed that ACP activated the Nrf2 signal. It was discovered in the mouse model that, ACP effectively improved liver injury in mice, decreased ALT and AST levels, and suppressed the expression of inflammatory factors. This study suggests that ACP can exert its effect against oxidative stress via the Nrf2‐ARE signalling, which further improves the production of ROS and the activation of TLR4‐NF‐κB signalling, and protects the liver against liver injury.

The expression of long non-coding RNA HOTAIR in advanced hepatocellular carcinoma and its prognostic correlation with sunitinib therapy

INTRODUCTION

The study was designed to assess the expression of long non-coding RNA HOTAIR (lncRNA HOTAIR) in tissues and peripheral blood of patients with advanced hepatocellular carcinoma (HCC). In addition, we also investigated the prognostic correlation between the expression level of lncRNA HOTAIR in tumour tissues and peripheral blood of patients with advanced HCC and sunitinib monotherapy.

MATERIAL AND METHODS

A total of 60 patients with advanced HCC who received sunitinib monotherapy and another 60 healthy individuals who were examined at the physical examination centre during the same period were included in the study. Real-time quantitative PCR (RT-QPCR) was used to determine the relative expression of lncRNA HOTAIR in tumour tissue, adjacent tissue, and peripheral blood of HCC patients as well as peripheral blood of healthy controls. Moreover, the clinicopathological information, overall survival (OS), and progression-free survival (PFS) were collected, followed by correlation analysis with lncRNA HOTAIR expression.

RESULTS

The expression of lncRNA HOTAIR was significantly higher in tumour tissues compared to that in adjacent tissues (t = 9.03, p < 0.001). The expression of lncRNA HOTAIR in peripheral blood of HCC patients was higher than that in healthy controls (t = 8.04, p < 0.001). There was a correlation between the expression of lncRNA HOTAIR in tumour tissue and peripheral blood in HCC patients (r = 0.638, p < 0.001). Patients with low lncRNA HOTAIR expression in tumour tissues harboured significantly longer OS (13.4 vs. 9.5, p < 0.001) and PFS (8.4 vs. 6.2, p < 0.001) compared to those with high expression. Consistently, patients with low lncRNA HOTAIR expression in peripheral blood had significantly prolonged OS (12.8 vs. 9.1, p < 0.001) and PFS (8.9 vs. 6.4, p < 0.001) compared to those with high expression. Patients with low expression both in tumour tissue and peripheral blood had prolonged OS (14.3 vs. 8.8, p < 0.001) and PFS (10.6 vs. 6.0, p < 0.001) compared to the rest of the patients. Cox regression analysis indicated that the expression level of lncRNA HOTAIR in tumour tissue and peripheral blood was an independent predictive factor of OS and PFS in patients with advanced HCC treated by sunitinib.

CONCLUSIONS

The expression of lncRNA HOTAIR was up-regulated in tumour tissue and peripheral blood in patients with advanced HCC. In addition, the expression level of lncRNA HOTAIR was one of the indicators predicting the effectiveness of sunitinib therapy.

Galloflavin Relieves the Malignant Behavior of Colorectal Cancer Cells in the Inflammatory Tumor Microenvironment

Background: In this study, we mainly aimed to explore the correlation between galloflavin and NLRP3 and its effect on colorectal cancer.

Methods: NLRP3 was overexpressed in SW480 cells; LPS + ATP was used to mimic the inflammatory microenvironment. Wound healing assay and Transwell assay were utilized to detect cell migration and invasion abilities; CCK-8 assay was performed to detect cell viability alterations; colony formation assay was conducted to detect colony formation ability; Western blot was used to detect the levels of NLRP3, ASC, C-Myc, and P21. SW480 cells were pretreated with high-dose and low-dose galloflavin, followed by observation of their effects on cell metastasis and invasion. NLRP3 was knocked out in SW480 to construct the SW480-NLRP3^−/− cell line, followed by high-dose galloflavin treatment and subsequent observation of cell metastasis and invasion abilities. Small molecule–protein docking and pull-down assay were performed to confirm the targeting relationship between galloflavin and NLRP3. After constructing a tumor-bearing mice model, galloflavin was intragastrically administered, followed by detection of tumor growth, expression of NLRP3 and ASC by immunohistochemistry, and tumor histopathology by H&E staining.

Results: After NLRP3 overexpression and LPS/ATP induction in SW480, the cell migration and invasion abilities were significantly enhanced, and cell viability was also enhanced. The activation of NLRP3 could promote the malignant behavior of colorectal cancer cells in the inflammatory microenvironment. Galloflavin treatment could significantly attenuate the malignant behavior of SW480 in the inflammatory microenvironment and inhibit the migration and invasion capabilities of SW480. The knockout of NLRP3 inhibited the effect of galloflavin, which did not significantly change the migration and invasion abilities. Molecular docking and pull-down assay revealed a targeted binding relationship between galloflavin and NLRP3 and that galloflavin is bound to NLRP3 not ASC protein. Moreover, galloflavin could inhibit tumor growth and decrease the expression of NLRP in tumor-bearing mice.

Conclusion: In this study, we found that NLRP3 could promote the migration and invasion of colorectal cancer cells in the inflammatory microenvironment. Galloflavin could inhibit the malignant behavior of colorectal cancer cells by targeting NLRP3.

Oridonin regulates the polarized state of Kupffer cells to alleviate nonalcoholic fatty liver disease through ROS-NF-κB

Oridonin (Ori) is a kind of diterpenoid small molecule, but its role in nonalcoholic fatty liver disease (NAFLD) has not been reported yet. This study aimed to explore the pharmacological function of Ori in liver protection through the reactive oxygen species (ROS)-mediated polarization of Kupffer cells (KCs). In the present work, KCs were adopted for study in vitro. To be specific, LPS and IFN-γ were utilized to induce M1 polarization, then the influence of Ori intervention on the expression of inflammatory factors IL-1β, IL-6 and TNF-α was detected by enzyme-linked immunosorbent assay (ELISA), that of CD86 and P65 was measured through fluorescence staining, that of p-P65 and p-P50 was detected by Western blotting (WB) assay, and ROS expression was measured by using the DCFH-DA probe. The C57BL/6J mice were fed with the high fat diet (HFD) to construct the NAFLD model, and intervened with Ori. The blood glucose (BG), body weight (BW), food intake and water intake of mice were monitored; meanwhile, glucose and insulin tolerance tests were conducted. The liver tissues of mice were subjected to H&E staining and oil red O staining. Moreover, the serum ALT, AST and TG levels in mice were monitored, the CD86 and CD206 levels were measured through histochemical staining, the expression of inflammatory factors was detected by ELISA, and the p-P65 and p-P50 protein levels were detected by WB assay. Ori suppressed the M1 polarization of KCs, reduced the levels of inflammatory factors, and decreased the expression of ROS, p-P65 and p-P50. In animal experiments, Ori improved lipid deposition and liver injury in the liver tissues of NAFLD mice, increased the proportion of M2 cells (up-regulated CD206 expression), reduced that of M1 cells (down-regulated CD86 expression), and decreased the serum ALT, AST and TG levels. This study discovered that Ori suppressed ROS production and regulated the M1 polarization of KCs, thus protecting the liver in NAFLD.

Mechanism of piperine in affecting apoptosis and proliferation of gastric cancer cells via ROS-mitochondria-associated signalling pathway

Piperine (PIP), the main active ingredient in pepper, belongs to the cinnamamide alkaloid. PIP has been found to have functions, including anti-oxidation, immune regulation, anti-tumour and promotion of drug metabolism. The present study was mainly designed to reveal the anti-tumour effect of PIP against gastric cancer and the relevant mechanism. In brief, the undifferentiated human gastric cancer cell HGC-27 was used, which was treated with different concentrations of PIP. As a result, PIP could inhibit proliferation and induce apoptosis of HGC-27 cells in a dose-dependent manner. The mechanism of PIP was associated with ROS increase and mitochondrial damage, simultaneously, the expression of key proteins of apoptosis was affected, including Bcl-2, Bax, Cyt-c, Caspase-9 and Caspase-3. Pre-treatment of ROS scavenger NAC HGC-27 cells could significantly reduce PIP-induced apoptosis and inhibit the activation of apoptotic signals. Consistently, PIP could induce ROS to increase and activate apoptotic signals in the animal model. Therefore, the present study showed that PIP can induce the generation of ROS, thereby promoting the activation of mitochondrial apoptotic pathway and exerting anti-tumour effects.

Antcin A alleviates pyroptosis and inflammatory response in Kupffercells of non-alcoholic fatty liver disease by targeting NLRP3

Pyroptosis, a pattern of inflammatory death, is regulated by NLRP3-Caspase-1 inflammasome and GSDMD-FL protein. Antcin A is a small triterpenoid molecule. In this study, Kupffer cells (KC) were used for in vitro model, which were treated with LPS and Nigericin (L/N) to induce pyroptosis. ELISA was used to determine the influence of Antcin A on the expression of inflammatory factors, IF was utilized to investigate NLRP3 and Caspase-1, PI staining was used to detect the opening level of membrane pores in KCs, C57BL/6J wild-type mice were fed with high-fat diet to construct a NAFLD model, and were simultaneously treated with Antcin A. H&E staining was used to detect hepatic pathological changes in mice, oil red staining was utilized to detect hepatic fat deposits in mice, IHC was used to detect the expression of NLRP3 and Caspase-1, Western blot was used to detect the expression levels of NLRP3 inflammasome (including NLRP3, ASC, Caspase-1, GSDMD-FL and GSDMD-NT). Pull-down assay and immunoprecipitation assay were used to detect the binding between Antcin A and NLRP3. As a result, Antcin A could significantly inhibit the occurrence of pyrolysis, decrease the expression of inflammatory factors, inhibit the activation and assembly of NLRP3 inflammasome, and significantly down-regulate the expression of NLRP3, Caspase-1 and GSDMD-NT in KCs. In NAFLD mice, Antcin A could suppress the inflammatory response in liver tissues of mice, reduce lipid deposition, down-regulate the levels of ALT and AST, and improve liver function in mice. Antcin A could also inhibit the activation of NLRP3 inflammasome in liver tissue and decrease the level of inflammatory factors. In the study of mechanism, we revealed that Antcin A could inhibit the assembly and activation of NLRP3 inflammasome by binding with NLRP3. In summary, in this study, we found that Antcin A could inhibit pyroptosis in KC and alleviate the inflammatory response of liver tissue in NAFLD by targeting NLRP3 inflammasome, which was one of the mechanisms of Anctin A in protecting liver.

SCFAs promote intestinal double-negative T cells to regulate the inflammatory response mediated by NLRP3 inflammasome

Short-chain fatty acids (SCFAs) are a product of intestinal bacteria metabolism. Our previous study has found that intestinal bacteria in patients with Alzheimer's disease (AD) can promote the activation of NLRP3 inflammasome and mediate neuroinflammation. In this study, we mainly explored the regulation of intestinal microenvironmental immunity by intestinal bacterial metabolite SCFAs and the mechanism of NLRP3 activation. First, wild-type (WT) and APP/PS1 mice were intervened with SCFAs. As a result, the proportion of double-negative T cells (CD3+CD4-CD8-, DNTs) in the intestine was increased, SCFAs could promote the expression of intestinal NLRP3 and inflammatory factors (IL-18, IL-6 and TNF-α). Moreover, SCAFs could also promote the level of inflammatory factors in the cerebrospinal fluid (CSF) of mice and aggravate the cognitive impairment in AD mice. CD3+ T cells isolated from the spleen were pre-treated with SCFAs, followed by detection of the proportion of DNTs. Consequently, SCFAs could promote the formation of DNTs, activate OX40 signal and simultaneously up-regulate the protein expression of Bcl-2, Bcl-xl and Survivin. Knockdown of OX40 could inhibit SCFAs-induced differentiation of DNTs. The co-culture of DNTs and intestinal macrophages showed that DNTs could activate Fas/FasL-TNF-α signal and induce the activation of NLRP3 inflammasome. In AD mouse models, treatment with Fas and TNFR1 inhibitors could significantly inhibit SCFAs-induced NLRP3 activation and inflammatory factors, while attenuate the inflammatory response in the brain tissue of mice and improve the cognitive ability of mice, however, without significant effect on the level of DNTs. The present study showed that SCFAs can promote the formation of DNTs through OX40. DNTs could induce the activation of NLRP3 inflammasome and the release of inflammatory factors in macrophages through Fas/FasL-TNF-α signals, thereby increasing the level of inflammatory factors in the central nervous system. When Fas and TNFR1 were inhibited by suppressing the functions of DNTs and macrophages, the activation of NLRP3 was inhibited. DNTs are affected by SCFAs, which is a new mechanism of neuroinflammation in AD.

Aureusidin derivative CNQX inhibits chronic colitis inflammation and mucosal barrier damage by targeting myeloid differentiation 2 protein

Our previous study has found that aureusidin can inhibit inflammation by targeting myeloid differentiation 2 (MD2) protein. Structural optimization of aureusidin gave rise to a derivative named CNQX. LPS was used to induce inflammation in intestinal macrophages; flow cytometry, PI staining and Hoechst 33342 staining were used to detect the apoptotic level of macrophages; enzyme-linked immunosorbent assay (ELISA) was utilized to detect the expression level of inflammatory factors (including IL-1β, IL-18 and TNF-α); immunofluorescence staining was used to investigate the expression of MD2; Western blot was employed to measure the protein level of TLR4, MD2, MyD88 and p-P65. As a result, CNQX with IC50 of 2.5 μM can significantly inhibit the inflammatory damage of macrophages, decrease apoptotic level, reduce the expression level of inflammatory factors and simultaneously decrease the expression level of TLR4, MD2, MyD88 as well as p-P65. Caco-2 cell line was used to simulate the intestinal mucosal barrier in vitro, LPS was employed to induce cell injury in Caco-2 (to up-regulate barrier permeability), and CNQX with IC50 of 2.5 μl was used for intervention. Flow cytometry was used to detect the apoptotic level of Caco-2 cells, trans-epithelial electric resistance (TEER) was measured, FITC-D was used to detect the permeability of the intestinal mucosa, and Western blot was used to detect the expression levels of tight junction proteins (including occludin, claudin-1, MyD88, TLR4 and MD2). As a result, CNQX decreased the apoptotic level of Caco-2 cells, increased TEER value, decreased the expression levels of MyD88, TLR4 and MD2, and increased the protein levels of tight junction proteins (including occludin and claudin-1). C57BL/6 wild-type mice were treated with drinking water containing Dextran sulphate sodium (DSS) to establish murine chronic colitis model. After CQNX intervention, we detected the bodyweight, DAI score and H&E tissue staining to evaluate the life status and pathological changes. Immunohistochemistry (IHC) staining was used to detect the expression of MD2 protein, tight junction protein (including occludin and claudin-1). Transmission electron microscopy and FITC-D were used to detect intestinal mucosal permeability. Western blot was used to detect the expression levels of tight junction proteins (including occludin, claudin-1, MyD88, TLR4 and MD2) in the intestinal mucosa tissue. Consequently, CNQX can inhibit the intestinal inflammatory response in mice with colitis, inhibit the mucosal barrier injury, increase the expression of tight junction proteins (including occludin and claudin-1) and decrease the expression levels of MyD88, TLR4 and MD2. Mechanistically, pull-down and immunoprecipitation assays showed that CNQX can inhibit the activation of TLR4/MD2-NF-κB by binding to MD2 protein. Collectively, in this study, we found that CNQX can suppress the activation of TLR4 signals by targeting MD2 protein, thereby inhibiting inflammation and mucosal barrier damage of chronic colitis.

The Mechanism of Aureusidin in Suppressing Inflammatory Response in Acute Liver Injury by Regulating MD2

Objective

In this study, we mainly explored the mechanism and target of the anti-inflammatory effects of Aureusidin (Aur) in acute liver injury.

Methods

Lipopolysaccharide (LPS) was used to induce inflammatory injury in Kupffer cells (KCs) in vitro. After Aur treatment with gradient concentration, flow cytometry, propidium iodide (PI) staining, and Hoechst 33342 staining were used to detect the apoptotic level of KCs, and an enzyme-linked immunosorbent assay (ELISA) was used to detect the expression levels of inflammatory factors, including Interleukin-1β (IL-1β), Interleukin-18 (IL-18), and tumor necrosis factor alpha (TNF-α). Western blot was used to detect the expression of toll-like receptor 4 (TLR4), myeloid differentiation protein-2 (MD2), MyD88, and p-P65. Aur was labeled with biotin, followed by a pull-down assay to detect its binding with MD2. Moreover, D-GalN/LPS was used to induce acute liver injury in mice in vitro, followed by Aur treatment by gavage. H&E staining was used to detect the pathological changes of liver tissue, an IF assay was used to detect the expression of MD2, Western blot was used to detect the expression of relevant proteins.

Results

Aur pretreatment could significantly inhibit LPS-induced KC injury, downregulate the apoptotic level, inhibit the expression of inflammatory factors, decrease the level of MDA, and downregulate the expression of MD2 in cells. Aur could inhibit the activation level of TLR4/MD2-NF-κB in a dose-dependent pattern, a high dose of Aur had a superior effect compared to low-dose Aur. In the case of MD2 deletion, the effects of Aur were suppressed. Additionally, pull-down and co-immunoprecipitation assays show that Aur can bind with the MD2 protein to inhibit the activation of TLR4/MD2-NF-κB. Results of mice experiments also showed that Aur could relieve liver injury, decrease the levels of ALT and AST, and simultaneously downregulate the levels of inflammatory factors in tissues and peripheral blood.

Conclusion

We found that Aur exerted an anti-inflammatory effect by directly targeting the MD2 protein, further inhibiting the expression of TLR4/MD2-NF-κB, thereby relieving acute liver injury. Therefore, Aur might be a potential inhibitor for MD2.

The effects and mechanisms of myeloid differentiation protein 2 on intestinal mucosal permeability in mice with chronic colitis

The present study was designed to investigate the mechanism of myeloid differentiation protein 2 (MD2) on intestinal mucosa destruction in mice with chronic colitis. Briefly, a chronic colitis mouse model was established by the administration of dextran sulfate sodium (DSS) in transgenic mice of MD2 overexpression (Transgenic, MD2-Tg) and C57BL/6 wild-type mice (MD2-WT). In addition, Caco-2 cells were cultured to form a monolayer cell model in vitro. The small interfering RNA was utilized to silence the MD2 gene in Caco-2 cells, and tumor necrosis factor-α (TNF-α) was used to establish the model of intestinal mucosal inflammation. After DSS induction, the intestinal mucosal tissue inflammation was more severe in MD2-Tg mice than MD2-WT. In addition, the intestinal mucosa was severely damaged, the intestinal mucosal permeability was increased, bacterial translocation was obvious, and the expression levels of MD2, MyD88, Toll-like receptor 4 (TLR4), and HMGB1 in mucosal tissues were significantly increased, while the expression levels of tight junction proteins, occludin, and claudin-1 were significantly lower in MD2-Tg mice compared with those in MD2-WT mice. TNF-α could induce inflammatory apoptosis in Caco-2 cell models. After MD2 silencing, the apoptotic level was decreased, the value of transepithelial electrical resistance was increased, the permeability of intestinal mucosa was decreased, the cellular expression levels of MD2, MyD88, TLR4, and HMGB1 were decreased, while the expression levels of tight junction proteins, occludin and claudin-1 were increased. MD2 could aggravate the destruction of intestinal mucosa in chronic colitis through the HMGB1-TLR4-MyD88 pathway.

SEGMENTATION OF ORGANS AT RISK IN THORACIC CT IMAGES USING A SHARPMASK ARCHITECTURE AND CONDITIONAL RANDOM FIELDS

Cancer is one of the leading causes of death worldwide. Radiotherapy is a standard treatment for this condition and the first step of the radiotherapy process is to identify the target volumes to be targeted and the healthy organs at risk (OAR) to be protected. Unlike previous methods for automatic segmentation of OAR that typically use local information and individually segment each OAR, in this paper, we propose a deep learning framework for the joint segmentation of OAR in CT images of the thorax, specifically the heart, esophagus, trachea and the aorta. Making use of Fully Convolutional Networks (FCN), we present several extensions that improve the performance, including a new architecture that allows to use low level features with high level information, effectively combining local and global information for improving the localization accuracy. Finally, by using Conditional Random Fields (specifically the CRF as Recurrent Neural Network model), we are able to account for relationships between the organs to further improve the segmentation results. Experiments demonstrate competitive performance on a dataset of 30 CT scans.

A model for the coupling of the Greater Bairam and local environmental factors in promoting Rift-Valley Fever epizootics in Egypt

OBJECTIVES

Rift-Valley Fever (RVF) is a zoonotic mosquito-borne disease in Africa and the Arabian Peninsula. Drivers for this disease vary by region and are not well understood for North African countries such as Egypt. A deeper understanding of RVF risk factors would inform disease management policies.

STUDY DESIGN

The present study employs mathematical and computational modeling techniques to ascertain the extent to which the severity of RVF epizootics in Egypt differs depending on the interaction between imported ruminant and environmentally-constrained mosquito populations.

METHODS

An ordinary differential system of equations, a numerical model, and an individual-based model (IBM) were constructed to represent RVF disease dynamics between localized mosquitoes and ruminants being imported into Egypt for the Greater Bairam. Four cases, corresponding to the Greater Bairam's occurrence during distinct quarters of the solar year, were set up in both models to assess whether the different season-associated mosquito populations present during the Greater Bairam resulted in RVF epizootics of variable magnitudes.

RESULTS

The numerical model and the IBM produced nearly identical results: ruminant and mosquito population plots for both models were similar in shape and magnitude for all four cases. In both models, all four cases differed in the severity of their corresponding simulated RVF epizootics. The four cases, ranked by the severity of the simulated RVF epizootics in descending order, correspond with the occurrence of the Greater Bairam on the following months: July, October, April, and January. The numerical model was assessed for sensitivity with respect to parameter values and exhibited a high degree of robustness.

CONCLUSIONS

Limiting the importation of infected ruminants beginning one month prior to the Greater Bairam festival (on years in which the festival falls between the months of July and October: 2014-2022) might be a feasible way of mitigating future RVF epizootics in Egypt.

Segmentation of heterogeneous or small FDG PET positive tissue based on a 3D-locally adaptive random walk algorithm

A segmentation algorithm based on the random walk (RW) method, called 3D-LARW, has been developed to delineate small tumors or tumors with a heterogeneous distribution of FDG on PET images. Based on the original algorithm of RW [1], we propose an improved approach using new parameters depending on the Euclidean distance between two adjacent voxels instead of a fixed one and integrating probability densities of labels into the system of linear equations used in the RW. These improvements were evaluated and compared with the original RW method, a thresholding with a fixed value (40% of the maximum in the lesion), an adaptive thresholding algorithm on uniform spheres filled with FDG and FLAB method, on simulated heterogeneous spheres and on clinical data (14 patients). On these three different data, 3D-LARW has shown better segmentation results than the original RW algorithm and the three other methods. As expected, these improvements are more pronounced for the segmentation of small or tumors having heterogeneous FDG uptake.

Identification of Maillard reaction products on peanut allergens that influence binding to the receptor for advanced glycation end products

BACKGROUND

Recent immunological data demonstrated that dendritic cells preferentially recognize advanced glycation end product (AGE)-modified proteins, upregulate expression of the receptor for AGE (RAGE), and consequently bias the immune response toward allergy.

METHODS

Peanut extract was characterized by mass spectrometry (MS) to elucidate the specific residues and specific AGE modifications found in raw and roasted peanuts and on rAra h 1 that was artificially glycated by incubation with glucose or xylose. The binding of the RAGE-V1C1 domain to peanut allergens was assessed by PAGE and Western analysis with anti-Ara h 1, 2, and 3 antibodies. IgE binding to rAra h 1 was also assessed using the same methods.

RESULTS

AGE modifications were found on Ara h 1 and Ara h 3 in both raw and roasted peanut extract. No AGE modifications were found on Ara h 2. Mass spectrometry and Western blot analysis demonstrated that RAGE binds selectively to Ara h 1 and Ara h 3 derived from peanut extract, whereas the analysis failed to demonstrate Ara h 2 binding to RAGE. rAra h 1 with no AGE modifications did not bind RAGE; however, after AGE modification with xylose, rAra h 1 bound to RAGE.

CONCLUSIONS

AGE modifications to Ara h 1 and Ara h 3 can be found in both raw and roasted peanuts. Receptor for AGE was demonstrated to selectively interact with AGE-modified rAra h 1. If sensitization to peanut allergens occurs in dendritic cells via RAGE interactions, these cells are likely interacting with modified Ara h 1 and Ara h 3, but not Ara h 2.

Computationally predicted IgE epitopes of walnut allergens contribute to cross-reactivity with peanuts

BACKGROUND

Cross-reactivity between peanuts and tree nuts implies that similar immunoglobulin E (IgE) epitopes are present in their proteins.

OBJECTIVE

To determine whether walnut sequences similar to known peanut IgE-binding sequences, according to the property distance (PD) scale implemented in the Structural Database of Allergenic Proteins, react with IgE from sera of patients with allergy to walnut and/or peanut.

METHODS

  Patient sera were characterized by western blotting for IgE binding to nut protein extracts and to peptides from walnut and peanut allergens, similar to known peanut epitopes as defined by low PD values, synthesized on membranes. Competitive enzyme-linked immunosorbent assay (ELISA) was used to show that peanut and predicted walnut epitope sequences compete with purified Ara h 2 for binding to IgE in serum from a cross-reactive patient.

RESULTS

Sequences from the vicilin walnut allergen Jug r 2, which had low PD values to epitopes of the peanut allergen Ara h 2, a 2S albumin, bound to IgE in sera from five patients who reacted to either walnut or peanut or both. A walnut epitope recognized by sera from six patients mapped to a surface-exposed region on a model of the N-terminal pro-region of Jug r 2. This predicted walnut epitope competed for IgE binding to Ara h 2 in serum as well as the known IgE epitope from Ara h 2.

CONCLUSIONS

Sequences with low PD value (< 8.5) to known IgE epitopes could contribute to cross-reactivity between allergens. This further validates the PD scoring method for predicting cross-reactive epitopes in allergens.

Modelling the transmission dynamics of meticillin-resistant Staphylococcus aureus in Beijing Tongren hospital

Semi-professional volunteers work in many tertiary care hospitals in China as healthcare assistants. Proper infection control measures are needed to reduce nosocomial transmission involving volunteers. A compartmental model was constructed to describe the transmission characteristics of meticillin-resistant Staphylococcus aureus (MRSA) in the emergency ward (EW) and respiratory intensive care unit (RICU) for volunteers in Beijing Tongren Hospital, Beijing, China. The model consists of components describing uncolonized and colonized patients, uncontaminated and contaminated healthcare workers (HCWs), and uncontaminated and contaminated volunteers. The basic reproduction number (R(0)) was calculated, and the dependence of R(0) on various model parameters was analysed. Moreover, simulations of the model were performed for comparision with the reported data on the numbers of colonized patients in the EW and RICU from 3 March 2009 to 28 February 2010, respectively. Sensitivity analysis of R(0) showed that increasing handwashing compliance among HCWs and volunteers would reduce the risk of transmission dramatically. As volunteers care for patients on a one-to-one basis, this study showed that the number of MRSA-positive patients would increase if volunteers were replaced by HCWs. Therefore, in addition to improving hand hygiene among HCWs, the employment of properly trained volunteers is an attractive alternative to decrease MRSA and other multi-drug resistant bacteria infections in the hospital setting.

BioCARS: a synchrotron resource for time-resolved X-ray science

BioCARS, a NIH-supported national user facility for macromolecular time-resolved X-ray crystallography at the Advanced Photon Source (APS), has recently completed commissioning of an upgraded undulator-based beamline optimized for single-shot laser-pump X-ray-probe measurements with time resolution as short as 100 ps. The source consists of two in-line undulators with periods of 23 and 27 mm that together provide high-flux pink-beam capability at 12 keV as well as first-harmonic coverage from 6.8 to 19 keV. A high-heat-load chopper reduces the average power load on downstream components, thereby preserving the surface figure of a Kirkpatrick-Baez mirror system capable of focusing the X-ray beam to a spot size of 90 µm horizontal by 20 µm vertical. A high-speed chopper isolates single X-ray pulses at 1 kHz in both hybrid and 24-bunch modes of the APS storage ring. In hybrid mode each isolated X-ray pulse delivers up to ~4 × 10(10) photons to the sample, thereby achieving a time-averaged flux approaching that of fourth-generation X-FEL sources. A new high-power picosecond laser system delivers pulses tunable over the wavelength range 450-2000 nm. These pulses are synchronized to the storage-ring RF clock with long-term stability better than 10 ps RMS. Monochromatic experimental capability with Biosafety Level 3 certification has been retained.

Five-Year Longitudinal MRI Follow-up and (1)H Single Voxel MRS in 14 patients with Gliomatosis Treated with Temodal, Radiotherapy and Antiangiogenic Therapy

Gliomatosis cerebri (GC) is a challenging tumor, considered to have a poor prognosis and poor response to treatments. The purpose of this study is to better understand glial tumor metabolism and post chemotherapy, radiotherapy and antiangiogenic variations in a longitudinal study to determine cerebral variation in MRS area, amplitude, and ratios of metabolites and spectral profiles during a five year longitudinal follow-up in 14 patients with gliomatosis without initial hyperperfusion and treated with chemotherapy (Temozolomide (Temodal(®))), radiotherapy and subsequent antiangiogenic therapy. The study also aimed to detect changes in infiltration, proliferation, lipids or glycolytic metabolism, as these changes could be monitored longitudinally in humans with glial brain tumors (low and high grade) after therapy, using conventional magnetic resonance imaging (MRI), spectroscopy (MRS) and MR perfusion. Most patients had first initial clinical and MRS improvement and stable MRI. After 12 to 24 chemotherapy treatment cycles MRS usually showed an increase in the Cho/Cr ratio (proliferation) and sometimes contrast enhancements. Later, the patients showed clinical deterioration and radiotherapy was started. There was an improvement with radiotherapy that lasted nine to 18 months. This was followed by a worsening that led to try antiangiogenic therapy. Later in the evolution for three patients with hyperperfusion this symptom disappeared, but proliferation, infiltration and glycolytic metabolism remained at a high level. Spectroscopic and metabolic changes often occur well before clinical deterioration and sometimes before improvement. Therefore, MRS could be more sensitive and could detect changes earlier than MRI and is sometimes predictive. Despite the difficulty, the variability and unknown factors, these repeated measurements give us a better insight into the nature of the different processes, tumor progression and could lead to better understanding of therapeutic response.