Potassium dehydroandrographolide succinate regulates the MyD88/CDH13 signaling pathway to enhance vascular injury-induced pathological vascular remodeling / 中国天然药物

Pathological vascular remodeling is a hallmark of various vascular diseases. Previous research has established the significance of andrographolide in maintaining gastric vascular homeostasis and its pivotal role in modulating endothelial barrier dysfunction, which leads to pathological vascular remodeling. Potassium dehydroandrographolide succinate (PDA), a derivative of andrographolide, has been clinically utilized in the treatment of inflammatory diseases precipitated by viral infections. This study investigates the potential of PDA in regulating pathological vascular remodeling. The effect of PDA on vascular remodeling was assessed through the complete ligation of the carotid artery in C57BL/6 mice. Experimental approaches, including rat aortic primary smooth muscle cell culture, flow cytometry, bromodeoxyuridine (BrdU) incorporation assay, Boyden chamber cell migration assay, spheroid sprouting assay, and Matrigel-based tube formation assay, were employed to evaluate the influence of PDA on the proliferation and motility of smooth muscle cells (SMCs). Molecular docking simulations and co-immunoprecipitation assays were conducted to examine protein interactions. The results revealed that PDA exacerbates vascular injury-induced pathological remodeling, as evidenced by enhanced neointima formation. PDA treatment significantly increased the proliferation and migration of SMCs. Further mechanistic studies disclosed that PDA upregulated myeloid differentiation factor 88 (MyD88) expression in SMCs and interacted with T-cadherin (CDH13). This interaction augmented proliferation, migration, and extracellular matrix deposition, culminating in pathological vascular remodeling. Our findings underscore the critical role of PDA in the regulation of pathological vascular remodeling, mediated through the MyD88/CDH13 signaling pathway.

Leaky Gut Plays a Critical Role in the Pathophysiology of Autism in Mice by Activating the Lipopolysaccharide-Mediated Toll-Like Receptor 4-Myeloid Differentiation Factor 88-Nuclear Factor Kappa B Signaling Pathway / 神经科学通报·英文版

Increased intestinal barrier permeability, leaky gut, has been reported in patients with autism. However, its contribution to the development of autism has not been determined. We selected dextran sulfate sodium (DSS) to disrupt and metformin to repair the intestinal barrier in BTBR T+tf/J autistic mice to test this hypothesis. DSS treatment resulted in a decreased affinity for social proximity; however, autistic behaviors in mice were improved after the administration of metformin. We found an increased affinity for social proximity/social memory and decreased repetitive and anxiety-related behaviors. The concentration of lipopolysaccharides in blood decreased after the administration of metformin. The expression levels of the key molecules in the toll-like receptor 4 (TLR4)-myeloid differentiation factor 88 (MyD88)-nuclear factor kappa B (NF-κB) pathway and their downstream inflammatory cytokines in the cerebral cortex were both repressed. Thus, "leaky gut" could be a trigger for the development of autism via activation of the lipopolysaccharide-mediated TLR4-MyD88-NF-κB pathway.

Effects of Buyang Huanwu Decoction and Astragali Radix-Angelicae Sinensis Radix combination on inflammatory responses in atherosclerotic mice / 中国中药杂志

The study aims to observe the effects and explore the mechanisms of Buyang Huanwu Decoction and Astragali Radix-Angelicae Sinensis Radix combination in the treatment of the inflammatory response of mice with atherosclerosis(AS) via the Toll-like receptor 4(TLR4)/myeloid differentiation primary response protein 88(MyD88)/nuclear factor-κB(NF-κB) signaling pathway. Male ApoE~(-/-) mice were randomly assigned into a model group, a Buyang Huanwu Decoction group, an Astragali Radix-Angelicae Sinensis Radix combination group, and an atorvastatin group, and male C57BL/6J mice of the same weeks old were used as the control group. Other groups except the control group were given high-fat diets for 12 weeks to establish the AS model, and drugs were administrated by gavage. Aortic intimal hyperplasia thickness, blood lipid level, plasma inflammatory cytokine levels, M1/M2 macrophage markers, and expression levels of proteins in TLR4/MyD88/NF-κB pathway in the vessel wall were measured to evaluate the effects of drugs on AS lesions and inflammatory responses. The results showed that the AS model was successfully established with the ApoE~(-/-) mice fed with high-fat diets. Compared with the control group, the model group showed elevated plasma total cholesterol(TC), triglyceride(TG), and low-density lipoprotein cholesterol(LDL-c) levels(P<0.05), thickened intima(P<0.01), and increased plasma tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6) levels(P<0.01). Moreover, the model group showed increased expression of vascular cell adhesion molecule-1(VCAM-1) and inducible nitric oxide synthase(iNOS)(P<0.01), inhibited expression of endothelial nitric oxide synthase(eNOS) and cluster of differentiation 206(CD206)(P<0.01), and up-regulated mRNA and protein levels of TLR4, MyD88, NF-κB inhibitor alpha(IκBα), and NF-κB in the vessel wall(P<0.05). Compared with the model group, Buyang Huanwu Decoction and Astragali Radix-Angelicae Sinensis Radix combination lowered the plasma TC and LDL-c levels(P<0.01), alleviated the intimal hyperplasia(P<0.01), and reduced the plasma TNF-α and IL-6 levels(P<0.05). Moreover, the two interventions promoted the expression of eNOS and CD206(P<0.05), inhibited the expression of VCAM-1 and iNOS(P<0.01), and down-regulated the mRNA and protein levels of TLR4, MyD88, IκBα, and NF-κB(P<0.05) in the vessel wall. This study indicated that Buyang Huanwu Decoction and Astragali Radix-Angelicae Sinensis Radix combination could delay the progression of AS, inhibit the polarization of vascular wall macrophages toward M1 type, and attenuate vascular inflammatory response by inhibiting the activation of TLR4/MyD88/NF-κB signaling pathway in the vascular wall. Astragali Radix and Angelicae Sinensis Radix were the main pharmacological substances in Buyang Huanwu Decoction for alleviating the AS vascular inflammatory response.

Role of dendritic cells in MYD88-mediated immune recognition and osteoinduction initiated by the implantation of biomaterials / 国际口腔科学杂志·英文版

Bone substitute material implantation has become an important treatment strategy for the repair of oral and maxillofacial bone defects. Recent studies have shown that appropriate inflammatory and immune cells are essential factors in the process of osteoinduction of bone substitute materials. Previous studies have mainly focused on innate immune cells such as macrophages. In our previous work, we found that T lymphocytes, as adaptive immune cells, are also essential in the osteoinduction procedure. As the most important antigen-presenting cell, whether dendritic cells (DCs) can recognize non-antigen biomaterials and participate in osteoinduction was still unclear. In this study, we found that surgical trauma associated with materials implantation induces necrocytosis, and this causes the release of high mobility group protein-1 (HMGB1), which is adsorbed on the surface of bone substitute materials. Subsequently, HMGB1-adsorbed materials were recognized by the TLR4-MYD88-NFκB signal axis of dendritic cells, and the inflammatory response was activated. Finally, activated DCs release regeneration-related chemokines, recruit mesenchymal stem cells, and initiate the osteoinduction process. This study sheds light on the immune-regeneration process after bone substitute materials implantation, points out a potential direction for the development of bone substitute materials, and provides guidance for the development of clinical surgical methods.

Moxibustion improves experimental colitis in rats with Crohn's disease by regulating bile acid enterohepatic circulation and intestinal farnesoid X receptor / 中西医结合学报

OBJECTIVE@#This study was conducted to explore the mechanism of intestinal inflammation and barrier repair in Crohn's disease (CD) regulated by moxibustion through bile acid (BA) enterohepatic circulation and intestinal farnesoid X receptor (FXR).@*METHODS@#Sprague-Dawley rats were randomly divided into control group, CD model group, mild moxibustion group and herb-partitioned moxibustion group. CD model rats induced by 2,4,6-trinitrobenzene sulfonic acid were treated with mild moxibustion or herb-partitioned moxibustion at Tianshu (ST25) and Qihai (CV6). The changes in CD symptoms were rated according to the disease activity index score, the serum and colon tissues of rats were collected, and the pathological changes in colon tissues were observed via histopathology. Western blot, immunohistochemistry (IHC) and immunofluorescence were used to evaluate the improvement of moxibustion on intestinal inflammation and mucosal barrier in CD by the BA-FXR pathway.@*RESULTS@#Mild moxibustion and herb-partitioned moxibustion improved the symptoms of CD, inhibited inflammation and repaired mucosal damage to the colon in CD rats. Meanwhile, moxibustion could improve the abnormal expression of BA in the colon, liver and serum, downregulate the expression of interferon-γ and upregulate the expression of FXR mRNA, and inhibit Toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88) mRNA. The IHC results showed that moxibustion could upregulate the expression of FXR and mucin2 and inhibit TLR4 expression. Western blot showed that moxibustion inhibited the protein expression of TLR4 and MyD88 and upregulated the expression of FXR. Immunofluorescence image analysis showed that moxibustion increased the colocalization sites and intensity of FXR with TLR4 or nuclear factor-κB p65. In particular, herb-partitioned moxibustion has more advantages in improving BA and upregulating FXR and TLR4 in the colon.@*CONCLUSION@#Mild moxibustion and herb-partitioned moxibustion can improve CD by regulating the enterohepatic circulation stability of BA, activating colonic FXR, regulating the TLR4/MyD88 pathway, inhibiting intestinal inflammation and repairing the intestinal mucosal barrier. Herb-partitioned moxibustion seems to have more advantages in regulating BA enterohepatic circulation and FXR activation. Please cite this article as: Shen JC, Qi Q, Han D, Lu Y, Huang R, Zhu Y, Zhang LS, Qin XD, Zhang F, Wu HG, Liu HR. Moxibustion improves experimental colitis in rats with Crohn's disease by regulating bile acid enterohepatic circulation and intestinal farnesoid X receptor. J Integr Med. 2023; 21(2): 194-204.

Exploring the detection of MYD88 mutation in patients with Waldenström macroglobulinemia by different methods and specimens / 中华血液学杂志

Objective: To improve the positivity rate and accuracy of MYD88 mutation detection in patients with Waldenström macroglobulinemia (WM) . Methods: MYD88 mutation status was retrospectively evaluated in 66 patients diagnosed with WM in Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from June 2017 to June 2021. The positivity rate and accuracy of the different methods and specimens for MYD88 mutation detection were analyzed. Results: MYD88 mutations were detected in 51 of 66 patients with WM, with an overall positivity rate of 77%. The positivity rate of the next-generation sequencing (NGS) or allele-specific polymerase chain reaction (AS-PCR) was significantly higher than that of the first-generation Sanger sequencing (84% vs 71% vs 46%, P<0.05) . For the different specimens, the positivity rate for the lymph nodes or bone marrow was significantly higher than that of peripheral blood (79% vs 84% vs 52%, P<0.05) . The positivity rate of the MYD88 mutation in the lymph nodes, bone marrow, and peripheral blood determined by NGS was 86%, 90%, and 67%, respectively. The positivity rate in the lymph nodes, bone marrow, and peripheral blood detected by AS-PCR was 78%, 81%, and 53%, respectively. Thirty-nine patients with WM underwent ≥ 2 MYD88 mutation detections. The final MYD88 mutational status for each patient was used as the standard to determine the accuracy of the different methods and in different specimens. The accuracy of MYD88 mutation detection in the lymph nodes (n=18) and bone marrow (n=13) by NGS was significantly higher than that in the peripheral blood (n=4) (100% vs 100% vs 75%, P<0.05) . There was no statistically significant difference in the accuracy of MYD88 mutation detection by AS-PCR in the lymph nodes (n=15) , bone marrow (n=11) , or peripheral blood (n=16) (93% vs 91% vs 88%, P>0.05) . Conclusions: In the detection of the MYD88 mutation in patients diagnosed with WM, NGS or AS-PCR is more sensitive than Sanger sequencing. Lymph nodes and bone marrow specimens are better than peripheral blood specimens.

Anti-inflammatory effects of Abelmoschus manihot (L.) Medik. on LPS-induced cystitis in mice: potential candidate for cystitis treatment based on classic use / 中国天然药物

Abelmoschus manihot (L.) Medik. (A. manihot) is a traditional Chinese herbal medicine with a variety of pharmacological properties. It was first recorded in Jiayou Materia Medica dating back to the Song dynasty to eliminate urinary tract irritation by clearing away heat and diuretic effect. However, its pharmacological action on urinary tract infections has not been investigated. The present study aims to evaluate the anti-inflammatory activity of A. manihot on a mouse model of lipopolysaccharide (LPS)-induced cystitis. The results showed that A. manihot decreased white blood cell (WBC) count in urine sediments of the cystitis mice, alleviated bladder congestion, edema, as well as histopathological damage, reduced the expression levels of tumor necrosis factor-α, interleukin-6, and interleukin-1β simultaneously. Moreover, A. manihot administration significantly downregulated the expression levels of TLR4, MYD88, IκBα, p-IκBα, NF-κB p65, and p-NF-κB p65 in LPS-induced cystitis mice. These findings demonstrated the protective effect of A. manihot against LPS-induced cystitis, which is attributed to its anti-inflammatory profile by suppressing TLR4/MYD88/NF-κB pathways. Our results suggest that A. manihot could be a potential candidate for cystitis treatment.

Butyl alcohol extract of Baitouweng Decoction alleviates vulvovaginal candidiasis in mice by downregulating NLRP3 inflammasome and related signal pathways / 中国中药杂志

This study aims to explore the effect of butyl alcohol extract of Baitouweng Decoction(BAEB) on vulvovaginal candidiasis(VVC) in mice and to clarify the mechanism from Toll-like receptors(TLRs)/MyD88 and Dectin-1/Syk signal pathways and NLRP3 inflammasome. To be specific, female KM mice were randomized into control group(i.g., normal saline), model group, fluco-nazole group(i.g., 20 mg·kg~(-1)), and low-dose, medium-dose, and high-dose BAEB groups(i.g., 20, 40, and 80 mg·kg~(-1), respectively). VVC was induced in mice except the control group. After the modeling, administration began and lasted 7 days. The ge-neral conditions and body weight of mice were recorded every day. On the 1 st, 3 rd, 7 th, and 14 th after vaginal infection by Candida albicans, the fungal load in the vaginal lavage fluid of the mice was measured with the plate method, and the morphology of C. albicans in vaginal lavage fluid was observed based on Gram staining. After the mice were killed, vaginal tissues were subjected to hematoxylin-eosin(HE) staining and periodic acid-Schiff(PAS) staining for vaginal histopathological analysis. The content of cytokines in vaginal lavage fluid, such as interleukin(IL)-1β, IL-18, tumor necrosis factor-α(TNF-α), IL-6, and S100 a8, was determined by enzyme-linked immunosorbent assay(ELISA), and content of reactive oxygen species(ROS) in vaginal tissues by tissue ROS detection kit. The protein expression of NLRP3, ASC, caspase-1, Dectin-1, Syk, MyD88, TLR2, TLR4, and nuclear factor-κB(NF-κB) in vaginal tissues was detected by Western blot, and the levels and distribution of NLRP3, Dectin-1, Syk, MyD88, TLR2, and TLR4 in vaginal tissues were determined with the immunohistochemical method. The results show that BAEB can improve the general conditions of VVC mice, reduce the fungal load and C. albicans hyphae in vaginal secretion, decrease ROS content in vaginal tissues and content of cytokines in vaginal lavage fluid, and down-regulate the expression of NLRP3, ASC, caspase-1, Dectin-1, Syk, MyD88, TLR2, TLR4, and NF-κB in vaginal tissues. The above results indicate that BAEB exerts therapeutic effect on VVC mice by down-regulating the key proteins in the TLRs/MyD88 and Dectin-1/Syk signal pathways and NLRP3 inflammasome.

miR-139-5p protects septic mice with acute lung injury by inhibiting Toll-like receptor 4/Myeloid differentiation factor 88/Nuclear factor-&mac_kgr; B signaling pathway

OBJECTIVES: To investigate the role of miR-139-5p and the TLR4/MyD88/NF-κB signaling pathway in acute lung injury in septic mice. METHOD: A total of 140 healthy male SPF C57BL/6 mice were divided into seven groups, i.e., Normal, Control, NC, miR-139-5p mimic, miR-139-5p inhibitor, TAK-242, and miR-139-5p inhibitor+TAK-242 groups. The levels of miR-139-5p, proteins related to the TLR4/MyD88/NF-κB signaling pathway (TLR4, MyD88, and p-NF-κB p50), and MPO, SOD, GSH, and MDA in lung tissue were measured. The lung tissue wet-to-dry mass ratio (W/D), arterial oxygen partial pressure (PaO2), and carbon dioxide partial pressure (PaCO2) were measured. RESULTS: A web-based bioinformatic tool predicted that MyD88 was a target of miR-139-5p, which was verified by a dual luciferase reporter assay. Compared with those in the Normal group, the levels of miR-139-5p, PaO2, SOD, and GSH were significantly lower, while those of TLR4, MyD88, p-NF-κB p50, W/D, PaCO2, IL-1β, TNF-α, IL-6, MPO, and MDA were higher in all other groups. Moreover, compared with their levels in the Control group, these indicators exhibited contrasting results in the miR-139-5p mimic and TAK-242 groups, but were similar in the miR-139-5p inhibitor group. In the miR-139-5p inhibitor+TAK-242 group, acute lung injury, aggravated by miR-139-5p inhibitor, was partially rescued by TAK-242. CONCLUSION: miR-139-5p inhibits the TLR4/MyD88/NF-κB signaling pathway to alleviate acute lung injury in septic mice.

Regulatory effect of Di'ao Xinxuekang on TLR4/MyD88/NF-κB signaling pathway in atherosclerotic rats / 中国中药杂志

The aim of this paper was to observe the effect of Di'ao Xinxuekang(DXXK) on TLR4/MyD88/NF-κB signaling pathway in atherosclerotic rats, and to explore its anti-atherosclerotic mechanism. Sixty SD rats were randomly divided into normal group, model group, atorvastatin group(4.0 mg·kg~(-1)), and DXXK groups(100, 30, 10 mg·kg~(-1)), with 10 rats in each group. The atherosclerosis model was induced by high fat diet plus vitamin D_2. Experimental drugs were administered intragastrically once daily for 8 weeks starting from the 9 th week. Biochemical analyzers were used to detect levels of triglyceride(TG), total cholesterol(TC), low-density lipoprotein cholesterol(LDL-C) and high-density lipoprotein cholesterol(HDL-C) in blood lipid. The levels of serum tumor necrosis factor(TNF)-α, interleukin(IL)-6 and IL-1β were detected by ELISA. Pathological changes of aortic tissues were observed by using Sudan Ⅳ and HE staining. The mRNA and protein expressions of TLR4, MyD88 and NF-κB p65 in aortic tissues were detected by RT-PCR and Western blot, respectively. As compared with the model group, TC, TG, and LDL-C levels in serum were significantly decreased, HDL-C content was significantly increased, and levels of TNF-α, IL-6, and IL-1β in serum were significantly decreased in atorvastatin group and DXXK high and middle dose groups. Aortic lesions in atorvastatin group and DXXK group were significantly improved, and the mRNA and protein expressions of TLR4, MyD88, NF-κB p65 in the aorta were decreased. DXXK has a preventive and therapeutic effect on atherosclerosis in rats, and its mechanism may be related to inhibiting inflammatory reaction by regulating TLR4/MyD88/NF-κB signal transduction, thereby inhibiting the progression of atherosclerosis.

Experimental study on effect and mechanism of Danzhi Jiangtang Capsules on diabetic myocardial injury / 中国中药杂志

Diabetic cardiomyopathy( DCM) is one of the major cardiovascular complications of diabetes mellitus. Based on the clinical efficacy of Danzhi Jiangtang Capsules( DJC) in the prevention and treatment of diabetes and its cardiovascular complications,both in vivo and in vitro methods were adopted to investigate its effect and underlying mechanism of protecting myocardial injury induced by diabetes. The type 2 diabetic rats were prepared by feeding high-energy food combined with streptozotin( STZ) injection,and the effects of DJC were observed by blood sugar,blood lipid,hemodynamic index,cardiac weight index and the change of cardiac pathological morphology. The protein expressions of TLR4,MyD88 and NF-κB p65 in myocardial tissue were detected and the possible mechanism was preliminarily analyzed. Besides this,DJC containing serum was prepared,H9 c2 cardiomyocyte induced by high sugar were studied to investigate the mechanism of TLR4/MyD88/NF-κB signaling pathway regulating cardiomyocyte injury and the therapeutic effect of DJC. The results demonstrated that fasting blood sugar,glycosylated hemoglobin,total cholesterol and glycerol triglyceride were significantly reduced( P<0. 01,P<0. 05). Cardiac weight index,left ventricle weight index,LVEDP and the protein expressions of TLR4,MyD88 and NF-κB p65 were significantly reduced( P<0. 01,P<0. 05). LVSP,+dp/dtmaxand-dp/dtmaxincreased significantly( P<0. 01,P< 0. 05). Moreover,the pathological damage of myocardial tissue in rats improved significantly. Meanwhile,the protein expressions of TLR4,MyD88 and NF-κB p65 in cardiomyocytes induced by high sugar were significantly inhibited( P<0. 01).It showed that DJC were effective in preventing and treating myocardial injury induced by diabetes and its mechanism may be related to the over-expression of TLR4/MyD88/NF-κB signaling pathway induced by high sugar.

Toll-like receptor 7 involves the injury in acute kidney ischemia/reperfusion of STZ-induced diabetic rats

ABSTRACT PURPOSE: To determine whether Toll-like receptor 7 (TLR7) is the potential targets of prevention or progression in the renal ischemia/reperfusion (I/R) injury of STZ-induced diabetic rats. METHODS: Thirty six Sprague-Dawley rats were randomly arranged to the nondiabetic (ND) or diabetic group (DM), with each group further divided into sham (no I/R injury), I/R (ischemia-reperfusion) and CD (given by Chloroquine) group. Preoperatively, Chloroquine (40 mg/kg, intraperitoneal injection.) was administrated 6 days for treatment group. I/R animals were subjected to 25 min of bilateral renal ischemia. Renal function, histology, apoptosis, cytokines, expression of TLR7, MyD88 and NF-κB were detected. RESULTS: The serum levels of blood urea nitrogen, creatinine, IL-6 and TNF-α, apoptotic tubular epithelial cells, expression of TLR7, MyD88 and NF-κB were significantly increased in DM+I/R group, compared with ND+I/R group (p<0.05). All these changes were further improved by TLR7 inhibition Chloroquine except Paller scores (p<0.05). CONCLUSION: Toll-like receptor 7 inhibition attenuates the acute renal ischemia/reperfusion injury of STZ-induced diabetic in SD rats.

Overexpression of myeloid differentiation protein 88 in mice induces mild cardiac dysfunction, but no deficit in heart morphology

Cardiac remodeling involves changes in heart shape, size, structure, and function after injury to the myocardium. The proinflammatory adaptor protein myeloid differentiation protein 88 (MyD88) contributes to cardiac remodeling. To investigate whether excessive MyD88 levels initiate spontaneous cardiac remodeling at the whole-organism level, we generated a transgenic MyD88 mouse model with a cardiac-specific promoter. MyD88 mice (male, 20-30 g, n=∼80) were born at the expected Mendelian ratio and demonstrated similar morphology of the heart and cardiomyocytes with that of wild-type controls. Although heart weight was unaffected, cardiac contractility of MyD88 hearts was mildly reduced, as shown by echocardiographic examination, compared with wild-type controls. Moreover, the cardiac dysfunction phenotype was associated with elevation of ANF and BNP expression. Collectively, our data provide novel evidence of the critical role of balanced MyD88 signaling in maintaining physiological function in the adult heart.

MyD88-BLT2-dependent cascade contributes to LPS-induced interleukin-6 production in mouse macrophage

Endotoxic responses to bacterial lipopolysaccharide (LPS) are triggered by Toll-like receptor 4 (TLR4) and involve the production of inflammatory mediators, including interleukin-6 (IL-6), by macrophages. The detailed mechanism of IL-6 production by macrophages in response to LPS has remained unclear, however. We now show that LPS induces IL-6 synthesis in mouse peritoneal macrophages via the leukotriene B4 receptor BLT2. Our results suggest that TLR4-MyD88 signaling functions upstream of BLT2 and that the generation of reactive oxygen species (ROS) by NADPH oxidase 1 (Nox1) and consequent activation of the transcription factor nuclear factor (NF)-kappaB function downstream of BLT2 in this response. These results suggest that a TLR4-MyD88-BLT2-Nox1-ROS-NF-kappaB pathway contributes to the synthesis of IL-6 in LPS-stimulated mouse macrophages.

Normalization of the levels of inflammatory molecules in Mycobacterium smegmatis-infected U937 cells by fibrate pretreatment

BACKGROUND: Tuberculosis (TB) is a respiratory tract disease caused by Mycobacterium tuberculosis infection. M. tuberculosis exploits immune privilege to grow and divide in pleural macrophages. Fibrates are associated with the immune response and control lipid metabolism through glycolysis with ß-oxidation of fatty acids. RESULTS: In this study, we investigated the effect of fibrate pretreatment on the immune response during M. smegmatis infection in U937 cells, a human leukemic monocyte lymphoma cell line. The protein expression of tumor necrosis factor α (TNF-α), an inflammatory marker, and myeloid differentiation primary response gene 88 (MyD88), a toll like receptor adaptor molecule, in the infected group increased at 1 and 6 h after M. smegmatis infection of U937 cells. Acetyl coenzyme A acetyl transferase-1 (ACAT-1), peroxisome proliferator-activated receptor-α (PPAR-α), TNF-α, and MyD88 decreased in U937 cells treated with fibrates at 12 and 24 h after treatment. More than a 24 h pretreatment with fibrate resulted in similar expression levels of ACAT-1 and PPAR-α between infected vehicle control and infected groups which were pretreated with fibrate for 24 h. However, upon exposure to M. smegmatis, the cellular expression of the TNF-α and MyD88 in the infected groups pretreated with fibrate for 24 h decreased significantly compared to that in the infected vehicle group. CONCLUSION: These results suggest that fibrate pretreatment normalized the levels of inflammatory molecules in Mycobacterium smegmatis-infected U937 cells. Further studies are needed to confirm the findings on pathophysiology and immune defense mechanism of U937 by fibrates during M. tuberculosis infection.

Rhamnogalacturonan II is a Toll-like receptor 4 agonist that inhibits tumor growth by activating dendritic cell-mediated CD8+ T cells

We evaluated the effectiveness of rhamnogalacturonan II (RG-II)-stimulated bone marrow-derived dendritic cells (BMDCs) vaccination on the induction of antitumor immunity in a mouse lymphoma model using EG7-lymphoma cells expressing ovalbumin (OVA). BMDCs treated with RG-II had an activated phenotype. RG-II induced interleukin (IL)-12, IL-1beta, tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) production during dendritic cell (DC) maturation. BMDCs stimulated with RG-II facilitate the proliferation of CD8+ T cells. Using BMDCs from the mice deficient in Toll-like receptors (TLRs), we revealed that RG-II activity is dependent on TLR4. RG-II showed a preventive effect of immunization with OVA-pulsed BMDCs against EG7 lymphoma. These results suggested that RG-II expedites the DC-based immune response through the TLR4 signaling pathway.