Levels Of Tumor Necrosis Factor Receptor-associated Factor 6 Research Articles

Protective effect of tumor necrosis factor receptor-associated factor 6 inhibitor C25-140 on acute kidney injury induced by diquat poisoning in mice

To investigate the protective effect and mechanism of tumor necrosis factor receptor-associated factor 6 (TRAF6) inhibitor C25-140 on acute kidney injury (AKI) induced by acute diquat (DQ) poisoning in mice. A total of 80 SPF grade healthy male C57BL/6 mice were randomly divided into the normal control group, DQ model group, C25-140 intervention group, and C25-140 control group, with 20 mice in each group. The DQ poisoning mouse model was established by using one-time intraperitoneal injection of 1 mL of 40 mg/kg DQ solution. The normal control group and C25-140 control group were injected with an equal amount of pure water into the peritoneal cavity. After 4 hours of model establishment, the C25-140 intervention group and C25-140 control group were given intraperitoneal injection of C25-140 5 mg/kg. The normal control group and DQ model group were given equal amounts of pure water, once a day for 7 consecutive days. After 7 days, the mice were anesthetized, eye blood was collected, and renal tissue was collected after sacrifice. The pathological changes of renal tissue were observed under a light microscope and renal tissue structure and mitochondrial changes were observed under transmission electron microscopy. The levels of serum creatinine (SCr) and blood urea nitrogen (BUN) were measured. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of serum interleukins (IL-6, IL-1β) and tumor necrosis factor-α (TNF-α). Western blotting was used to detect the protein expression levels of TRAF6, myeloid differentiation factor 88 (MyD88), and nuclear factor-κB (NF-κB) in renal tissue. Chemical method was used to determine the content of serum malondialdehyde (MDA) and superoxide dismutase (SOD). During the observation period, there were no abnormal behaviors in the normal control group mice. The DQ model group mice gradually showed symptoms such as mental fatigue, fluffy fur, reduced activity, and low food intake after being exposed to the toxin, and severe cases resulted in death. The above symptoms were alleviated in the C25-140 intervention group compared to the DQ model group. Under light microscopy, HE staining showed infiltration of inflammatory cells, glomerulosclerosis, proximal tubular dilation, and vacuolization in the DQ model group, while the inflammatory response was reduced in the C25-140 intervention group compared to the DQ model group. Under transmission electron microscopy, the DQ model group showed relatively high levels of mitochondrial damage, severe swelling, increased volume, matrix dissolution, ridge fracture and loss. The degree of mitochondrial damage in the C25-140 intervention group was reduced compared to the DQ model group. Compared with the normal control group, the levels of serum SCr, BUN, IL-6, IL-1β, TNF-α, and MDA in the DQ model group were significantly increased, while the serum SOD level was significantly decreased. Compared with the DQ model group, the levels of serum SCr, BUN, IL-6, IL-1β, TNF-α, and MDA in the C25-140 intervention group were significantly reduced [SCr (μmol/L): 59.07±13.11 vs. 83.61±20.13, BUN (mmol/L): 25.83±9.95 vs. 40.78±11.53, IL-6 (ng/L): 40.76±7.03 vs. 83.33±21.83, IL-1β (ng/L): 53.87±7.82 vs. 91.74±12.53, TNF-α (ng/L): 102.52±32.13 vs. 150.92±31.75, MDA (μmol/L): 3.57±1.06 vs. 5.75±1.83], and the serum SOD level was significantly increased (kU/g: 162.52±36.13 vs. 122.72±22.13), and the differences were statistically significant (all P < 0.01). Western blotting results showed that the protein expression levels of TRAF6, NF-κB, and MyD88 in the renal tissue of DQ model group mice were significantly higher than those in the normal control group. The expression levels of the above-mentioned proteins in the C25-140 intervention group of mice were significantly lower than those in the DQ model group (TRAF6/β-actin: 1.05±0.36 vs. 1.74±0.80, NF-κB/β-actin: 0.57±0.07 vs. 1.03±0.75, MyD88/β-actin: 0.58±0.07 vs. 1.03±0.33, all P < 0.05). TRAF6 inhibitor C25-140 can alleviate AKI induced by DQ poisoning in mice by regulating the Toll-like receptor 4 (TLR4)/TRAF6/NF-κB signaling pathway and downregulating the levels of inflammatory cytokines IL-1β, IL-6, and TNF-α.

Silenced long non-coding RNA RMST ameliorates cardiac dysfunction and inflammatory response in doxorubicin-induced heart failure in C57BL/6 mice via the modulation of the microRNA-10b-5p/TRAF6 axis.

Long non-coding RNA rhabdomyosarcoma 2-associated transcript (RMST) has been found to exert effects on cardiovascular diseases. However, the research for probing its role in heart failure (HF) is limited. Our study intends to unravel the regulatory effects of RMST on HF via the microRNA (miR)-10b-5p/tumor necrosis factor receptor-associated factor 6 (TRAF6) axis. The mouse model of HF was induced by doxorubicin. The expression levels of RMST, miR-10b-5p and TRAF6 were detected. The virus carrying RMST, miR-10b-5p or TRAF6 vectors were injected into doxorubicin-induced HF mice to examine the cardiac function, inflammatory response, pathological changes and cell apoptosis in doxorubicin-induced HF mice. The target relationships among RMST, miR-10b-5p and TRAF6 were confirmed. RMST and TRAF6 were elevated and miR-10b-5p was reduced in doxorubicin-induced HF mice. RMST or TRAF6 silencing or miR-10b-5p overexpression could improve doxorubicin-induced cardiac dysfunction, and inflammatory response, and reduce cardiomyocyte apoptosis. Down-regulation of miR-10b-5p or overexpression of TRAF6 were both able to inverse the therapeutic effect of silencing RMST on doxorubicin-induced HF mice. RMST bound to miR-10b-5p that targeted TRAF6. RMST silencing could attenuate inflammatory response and cardiomyocyte apoptosis and upregulate cardiac function in mice with doxorubicin-induced HF by modulating the miR-10b-5p/TRAF6 axis. The study provides novel therapeutic targets for HF treatment.

Embryonic Lethal Abnormal Visual-Like Protein 1 Aggravates Caerulein-Induced AR42J Cell Injury and Macrophage M1 Polarization to Accelerate Acute Pancreatitis by Upregulating TRAF6.

Tumor necrosis factor receptor-associated factor 6 (TRAF6) has been found to promote the progression of acute pancreatitis (AP). However, its underlying molecular mechanisms in AP need to be further revealed. Caerulein-induced AR42J cells were used to construct AP cell models. Cell viability and apoptosis were measured by Cell Counting Kit 8 assay and flow cytometry. Levels of inflammatory factors and oxidative stress-related markers were assessed. The medium of AR42J cells was collected for coculturing RAW264.7 cells. Macrophage marker CD86+ cell rates were checked with flow cytometry. The levels of TRAF6, embryonic lethal abnormal visual-like protein 1 (ELAVL1), and inducible nitric oxide synthase (iNOS) were examined by Western blot or quantitative real-time polymerase chain reaction. RNA immunoprecipitation assay was performed to evaluate the interaction between ELAVL1 and TRAF6. TRAF6 mRNA stability was tested using actinomycin D treatment. Caerulein treatment suppressed viability, induced AR42J cell apoptosis, inflammation, oxidative stress, and accelerated macrophage M1 polarization. TRAF6 downregulation could alleviate caerulein-induced AR42J cell injury and macrophage M1 polarization. ELAVL1 interacted with TRAF6 to stabilize its expression. Meanwhile, ELAVL1 knockdown relieved caerulein-induced AR42J cell injury and macrophage M1 polarization, while these effects were abolished by TRAF6 overexpression. TRAF6, stabilized by ELAVL1, promoted caerulein-induced AR42J cell injury and macrophage M1 polarization, suggesting that it might accelerate AP9 progression.

Astragaloside IV relieves passive heymann nephritis and podocyte injury by suppressing the TRAF6/NF-κb axis

The pathogenesis of membranous nephropathy (MN) involves podocyte injury that is attributed to inflammatory responses induced by local immune deposits. Astragaloside IV (AS-IV) is known for its robust anti-inflammatory properties. Here, we investigated the effects of AS-IV on passive Heymann nephritis (PHN) rats and TNF-α-induced podocytes to determine the underlying molecular mechanisms of MN. Serum biochemical parameters, 24-h urine protein excretion and renal histopathology were evaluated in PHN and control rats. The expression of tumor necrosis factor receptor associated factor 6 (TRAF6), the phosphorylation of nuclear factor kappa B (p-NF-κB), the expression of associated proinflammatory cytokines (TNF-α, IL-6 and IL-1β) and the ubiquitination of TRAF6 were measured in PHN rats and TNF-α-induced podocytes. We detected a marked increase in mRNA expression of TNF-α, IL-6 and IL-1β and in the protein abundance of p-NF-κB and TRAF6 within the renal tissues of PHN rats and TNF-α-induced podocytes. Conversely, there was a reduction in the K48-linked ubiquitination of TRAF6. Additionally, AS-IV was effective in ameliorating serum creatinine, proteinuria, and renal histopathology in PHN rats. This effect was concomitant with the suppression of NF-κB pathway activation and decreased expression of TNF-α, IL-6, IL-1β and TRAF6. AS-IV decreased TRAF6 levels by promoting K48-linked ubiquitin conjugation to TRAF6, which triggered ubiquitin-mediated degradation. In summary, AS-IV averted renal impairment in PHN rats and TNF-α-induced podocytes, likely by modulating the inflammatory response through the TRAF6/NF-κB axis. Targeting TRAF6 holds therapeutic promise for managing MN.

Tocotrienol suppresses colitis-associated cancer progression through TLR4 signaling in a mouse model of colorectal cancer

This study aimed to evaluate the preventive efficacy of tocotrienol in inhibiting the nuclear factor-kappa B (NF-κB) mediated inflammation pathways in colorectal cancer. We utilized the azoxymethane (AOM) and dextran sulfate sodium salt (DSS) to induce colitis-associated colorectal cancer (CAC) mice model. In generating a CAC model, mice were intraperitoneally injected with AOM at a concentration of 10 mg/kg body weight. Seven days after the AOM injection, mice drinking water containing 3 % DSS for 1 week, followed by a 2-week period of regular water. This cycle of DSS treatment (1-week 3 % DSS+2-week water) was repeated for two additional cycles. Mice were randomly divided into five groups (n = 20/group), including Blank group, Model group, three different dosages tocotrienol groups (Low dose group [50 mg/kg], Medium dose group [75 mg/kg], and High dose group [100 mg/kg]). The protective effects of tocotrienol were assessed using histological, flow cytometry, western blot and mouse Luminex assay. Compared with the blank group, expressions of toll-like receptor 4 (TLR4), myeloid differentiation protein 88 (MyD88), tumor necrosis factor receptor-associated factor 6 (TRAF-6), NF-κB, Interleukin (IL)-6 and tumor necrosis factor (TNF) −α were increased in model group, while IL-4 and IL-10 were decreased in model group (P<0.05). Tocotrienol prevented carcinogenesis and decreased the IL-6, TNF-α, MyD88, TLR4, TRAF-6 and NF-κB expression levels, compared with the model group (P<0.05). Compared with the model group, the expression of IL-10 was increased in medium dose group and high dose group (P<0.05). The protective effects of tocotrienol may be related to the inhibition of TLR4 /MyD88 /NF-κB mediated inflammatory signaling pathways. Therefore, the use of tocotrienol can improve the abnormal expression of cytokines in a mouse model of colorectal cancer and inhibit the occurrence and development of colorectal cancer.

2,3,4',5-Tetrahydroxystilbene-2-O-β-d-glucoside attenuates atherosclerotic progression by inhibiting inflammation via downregulation of TNF receptor-associated factor 6 expression.

Atherosclerosis (As) is an inflammatory disease, and 2,3,4',5-tetrahydroxystilbene-2-O-β-d-glucoside (TSG) has been shown to suppress inflammation. However, it is still unclear if TSG alleviates As by inhibiting inflammation. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to assess the mRNA levels of tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6), TNF-α and interleukin-6 (IL-6) in lipoprotein E knockout (ApoE -/-) mice with As. Hematoxylin-eosin (H&E) staining was performed to examine the atherosclerotic plaques in the aortic sinus. QRT-PCR and western blotting were used to measure the expression levels of TRAF6, TNF-α, and IL-6 in human umbilical vein endothelial cells (HUVECs), and enzyme-linked immunosorbent assays (ELISAs) were performed to monitor the levels of TNF-α and IL-6 in serum and cell culture medium. TSG inhibited subendothelial plaques formation in the aortic sinus and inhibited the levels of total cholesterol (TCHO), low-density lipoprotein (LDL), TRAF6, TNF-α and IL-6 in AS mice in a dose-dependent manner. Moreover, TSG attenuated the oxidatively modified LDL (ox-LDL)-induced increases in TRAF6, TNF-α and IL-6 expression, whereas TRAF6 overexpression reversed the TSG-induced decreases in TRAF6, TNF-α, and IL-6 expression in HUVECs. TSG attenuates atherosclerotic progression by inhibiting inflammation via the downregulation of TRAF6 in ApoE-/- mice and HUVECs.

TRAF6 promotes Bacillus Calmette-Guérin-induced macrophage apoptosis through the intrinsic apoptosis pathway

To investigate the role of tumor necrosis factor receptor-associated factor 6 (TRAF6) in regulating Bacillus Calmette-Guérin (BCG)-induced macrophage apoptosis. The expression of TRAF6 in peripheral blood samples of 50 patients with active tuberculosis (TB) and 50 healthy individuals were detected using quantitative real-time PCR (qPCR). RAW264.7 macrophages were infected with BCG at different MOI and for different lengths of time, and the changes in expressions of Caspase 3 and TRAF6 were detected with Western blotting and qPCR. In a RAW264.7 cell model of BCG infection with TRAF6 knockdown established using RNA interference technique, the bacterial load was measured and cell apoptotic rate and mitochondrial membrane potential (MMP) were determined with flow cytometry. The expression levels of TRAF6, Caspase 3, PARP, BAX and Bcl-2 in the cells were detected using Western blotting, and the expressions of TRAF6 and Caspase 3 were also examined with immunofluorescence assay. The expression of TRAF6 was significantly upregulated in the peripheral blood of patients with active TB as compared with healthy subjects (P < 0.001). In RAW264.7 cells, BCG infection significantly increased the expressions of Caspase 3 and TRAF6, which were the highest in cells infected for 18 h and at the MOI of 15. TRAF6 knockdown caused a significant increase of bacterial load in BCG-infected macrophages (P=0.05), lowered the cell apoptotic rate (P < 0.001) and reduced the expressions of Caspase 3 (P=0.002) and PARP (P < 0.001). BCG-infected RAW264.7 cells showed a significantly increased MMP (P < 0.001), which was lowered by TRAF6 knockdown (P < 0.001); the cells with both TRAF6 knockdown and BCG infection showed a lowered BAX expression (P=0.005) and an increased expression of Bcl-2 (P=0.04). TRAF6 promotes BCG-induced macrophage apoptosis by regulating the intrinsic apoptosis pathway.

Chaihu Longgu Muli Decoction relieving temporal lobe epilepsy in rats by inhibiting TLR4 signaling pathway through miR-146a-3p and miR-146a-5p

ObjectiveTo explore the effect and mechanism of Chaihu Longgu Muli Decoction (柴胡龙骨牡蛎汤, CHLGMLD) in rats with temporal lobe epilepsy (TLE). MethodsA total of 80 Sprague-Dawley (SD) male rats were randomized into control (CON), model (MOD), carbamazepine (CBZ, 0.1 g/kg), CHLGMLD low dose (CHLGMLD-L, 12.5 g/kg), and high dose (CHLGMLD-H, 25 g/kg) groups, with 16 rats in each group. TLE rat models were established in the four groups with the use of lithium-pilocarpine except for the CON group. After the successful establishment of TLE models, all drugs were administered through gavage, and distilled water was given to rats in the CON and MOD groups for four weeks. The frequency and duration of seizures before and after treatment were recorded for the evaluation of the alleviation degree. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression levels of miR-146a-3p and miR-146a-5p. The expression levels of toll-like receptor 4 (TLR4), interleukin-1 receptor-associated kinase 1 (IRAK1), tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6), TAK1-binding protein (TAB), nuclear factor-kappa B (NF-κB), and interleukin-1 beta (IL-1β) in hippocampus were tested by immunofluorescence assay. Correlation analysis between the above factors and expressions of miR-146a-3p and miR-146a-5p were performed separately. ResultsCHLGMLD decreased the frequency (P < 0.05) and duration (P < 0.01) of seizures in rats. CHLGMLD down-regulated the expression levels of miR-146a-5p and miR-146a-3p (P < 0.05), and inhibited the expression levels of TLR4, IRAK1, TRAF6, TAB, NF-κB, and IL-1β (P < 0.01). The correlation analysis revealed that the expression levels of TLR4, IRAK1, TRAF6, TAB, NF-κB, and IL-1β were positively correlated with the expression levels of miR-146a-3p and miR-146a-5p detected by qRT-PCR, respectively (P < 0.01). ConclusionCHLGMLD can inhibite the TLR4 signaling pathway by lowering the expression levels of miR-146a-3p and miR-146a-5p to alleviate hippocampal dentate gyrus inflammation in TLE rats, thus relieving seizures.

IFT80 negatively regulates osteoclast differentiation via association with Cbl-b to disrupt TRAF6 stabilization and activation

Excess bone loss due to increased osteoclastogenesis is a significant clinical problem. Intraflagellar transport (IFT) proteins have been reported to regulate cell growth and differentiation. The role of IFT80, an IFT complex B protein, in osteoclasts (OCs) is completely unknown. Here, we demonstrate that deletion of IFT80 in the myeloid lineage led to increased OC formation and activity accompanied by severe bone loss in mice. IFT80 regulated OC formation by associating with Casitas B-lineage lymphoma proto-oncogene-b (Cbl-b) to promote protein stabilization and proteasomal degradation of tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6). IFT80 knockdown resulted in increased ubiquitination of Cbl-b and higher TRAF6 levels, thereby hyperactivating the receptor activator of nuclear factor-κβ (NF-κβ) ligand (RANKL) signaling axis and increased OC formation. Ectopic overexpression of IFT80 rescued osteolysis in a calvarial model of bone loss. We have thus identified a negative function of IFT80 in OCs.

Inhibitory effects of luteolin on TLR3-mediated inflammation caused by TAK/NF-κB signaling in human corneal fibroblasts.

To study the role of luteolin (LUT) in the expression of toll-like receptors 3 (TLR3) ligand polyI:C stimulated inflammatory factors in human corneal fibroblasts (HCFs). HCFs cells were cultivated with or without LUT or polyI:C. The expression levels of interleukin (IL)-6, IL-8, monocyte chemotactic protein-1 (MCP-1), vascular cell adhesion molecule (VCAM)-1, as well as intercellular adhesion molecule (ICAM)-1 were measured using enzyme-linked immunosorbent assay (ELISA), immunoblotting or reverse transcription-quantitative polymerase chain reaction (PCR) analyses. Immunoblotting was used to assess toll-interleukin-1 receptor-domain-containing adapter-inducing interferon-β (TRIF), TLR3, transforming growth factor-b-activated kinase 1 (TAK1), tumor necrosis factor receptor-associated factor 6 (TRAF6), the transcription factor AP-1, as well as transcription factor nuclear factor (NF-κB)-inhibitory protein IκB-α degradation and phosphorylation. Immunofluorescence assays were used to localize the cellular location of the p65 subunit of NF-κB. Corneal fibroblasts exposed to polyI:C demonstrated decreased VCAM-1, ICAM-1, MCP-1, IL-6, and IL-8 expression levels upon exposure to LUT in a time-dependent and concentration-dependent manner. LUT was observed to suppress polyI:C-triggered expression of TLR3, the translocation of NF-κB p65 into cell nuclei, as well as the phosphorylation of TAK, c-Jun, and IκB-α, while no impact on the expression levels of TRIF and TRAF6 were observed. LUT suppress the expression of proinflammatory adhesion molecules, chemokines, and cytokines in polyI:C exposed HCFs. These effects are likely mediated through TAK/NF-κB signal attenuation. Therefore, LUT is a candidate molecule that can prevent the TLR3-mediated inflammation response associated with corneal viral infection.

Screening of Antiviral Components of Yinhuapinggan Granule and Protective Effects of Yinhuapinggan Granule on MDCK Cells with Influenza A/H1N1 Virus.

Background Traditional Chinese medicine Yinhuapinggan granule (YHPG) has been used for treating upper respiratory tract infection like influenza, cough, and viral pneumonia. However, its active ingredients that really exert the main efficacy have not been well elucidated. This study is aimed at screening its antiviral components and investigating the potential therapeutic mechanisms of YHPG against the influenza A/PR8/34 (H1N1) virus in Madin Darby canine kidney (MDCK). Methods MDCK cells were infected with the influenza virus and then treated with ribavirin, YHPG, and main active ingredients in YHPG. Based on the maximum nontoxic concentration (TC0), half-maximal toxic concentration (TC50), half-maximal inhibitory concentration (IC50), and therapeutic index (TI), interferon-β (IFN-β) and interleukin-6 (IL-6) levels were measured using enzyme-linked immunosorbent assay (ELISA), and the gene expression of TLR7, MyD88, tumor necrosis factor receptor-associated factor 6 (TRAF6), c-Jun amino terminal kinase (JNK), p38 mitogen-activated protein kinase (p38 MAPK), and p65 nuclear transcription factor-kappa B (p65 NF-κB) was quantified using reverse transcription-polymerase chain reaction (RT-PCR). Results The results indicated that the components of YHPG, such as ephedrine hydrochloride, pseudoephedrine hydrochloride, chlorogenic acid, and emodin, had significant antiviral effects. High and medium doses of YHPG effectively reduced the cytopathic effect (CPE) and significantly decreased IFN-β and IL-6 levels in the supernatant. Simultaneously, the transcript levels of TLR7, MyD88, TRAF6, JNK, p38 MAPK, and p65 NF-κB decreased in infected MDCK cells. Moreover, a certain dose-dependent relationship among different groups of YHPG was observed. Conclusions These results indicated that YHPG and the components of YHPG had a significant inhibitory function on the proliferation of the H1N1 virus. The mechanism might be associated with suppressing the activation of the TLR7/MyD88 signaling pathway, a decrease in the mRNA expression of key target genes, and inhibition of IFN-β and IL-6 secretion.

Changes in the related indicators of bone formation and bone resorption in severely burned rats

Objective: To observe the changes in the related indicators of bone formation and bone resorption in severely burned rats. Methods: The experimental research method was adopted. Thirty female Sprague-Dawley rats aged 6 to 8 weeks were divided into sham injury group, 12% total body surface area (TBSA) full-thickness burn group, and 24%TBSA full-thickness burn group according to the random number table, with 10 rats in each group. The rats were treated on the back correspondingly, after which, the burned rats were rehydrated by intraperitoneal injection according to the Parkland formula, and the wound was coated with 20 g/L iodophor until wound healing. On post injury day (PID) 28, the tibia tissue of rats in each group was collected. The new bone tissue and the number of osteoclasts were observed after staining with Masson and tartrate-resistant acid phosphatase, respectively. The abdominal aortic blood of rats in each group was harvested for serum preparation. The bone metabolism indexes of serum calcium ion and phosphorus ion concentration were determined by the methyl thymol blue colorimetric method and phosphomolybdic acid method, respectively. The serum levels of bone formation marker of aminoterminal propeptide of type 1 procollagen (P1NP) and bone resorption marker of beta-carboxy-terminated peptide of type Ⅰ collagen (β-CTX) were determined by enzyme-linked immunosorbent assay. The first lumbar spine tissue of rats in each group was collected, and the mRNA expression levels of osteoprotegerin, receptor activator of nuclear factor-κB ligand (RANKL), tumor necrosis factor receptor-associated factor 6 (TRAF-6), nuclear factor of activated T cell 1 (NFATC1), c-Fos, and c-Src were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were statistically analyzed with one-way analysis of variance, Bonferroni method, Welch test, Games-Howell test, Kruskal-Wallis test, Mann-Whitney U test, and Bonferroni correction. Results: On PID 28, compared with that in sham injury group, the formation of new bone tissue in the tibia tissue of rats in the two burn groups was decreased, and the larger the burn area, the more obvious the decrease. The numbers of osteoclasts in the tibia tissue of rats in the two burn groups were similar, both significantly more than the number in sham injury group. On PID 28, the serum calcium ion concentration and serum level of β-CTX of rats in the three groups were similar (P>0.05). The serum phosphorus ion concentration of rats in 24%TBSA full-thickness burn group was significantly higher than that in 12%TBSA full-thickness burn group (P<0.05), and the serum phosphorus ion concentrations in the two burn groups were significantly higher than the concentration in sham injury group (P<0.01). The serum level of P1NP of rats in 24%TBSA full-thickness burn group was significantly lower than that in sham injury group (P<0.01). On PID 28, the mRNA expression levels of osteoprotegerin in the first lumbar spine tissue of rats in sham injury group, 12%TBSA full-thickness burn group, and 24%TBSA full-thickness burn group were 1.01±0.20, 1.71±0.83, and 2.24±0.51, respectively, and that in 24%TBSA full-thickness burn group was significantly higher than that in sham injury group (P<0.01). The mRNA expression level of RANKL in the first lumbar spine tissue of rats in 24%TBSA full-thickness burn group was 1.31±0.17, which was significantly higher than 1.00±0.14 in sham injury group and 0.97±0.10 in 12%TBSA full-thickness burn group (P<0.01). The mRNA expression levels of TRAF-6, NFATC1 (Z=3.141, 3.782), and c-Src in the first lumbar tissue of rats in 12%TBSA full-thickness burn group and 24%TBSA full-thickness burn group and the mRNA expression level of c-Fos in the first lumbar tissue of rats in 12%TBSA full-thickness burn group were significantly higher than those in sham injury group (P<0.05 or P<0.01). The mRNA expression levels of c-Fos and c-Src in the first lumbar spine tissue of rats in 12%TBSA full-thickness burn group were significantly higher than those in 24%TBSA full-thickness burn group (P<0.01). Conclusions: Severe burns can cause a decrease in the generation of new bone tissue, an increase in the number of osteoclasts and the serum phosphorus ion concentration, and a decrease in the serum level of P1NP in rats. The level of osteoprotegerin, RANKL, TRAF-6, NFATC1, c-Fos, and c-Src in bone tissue showed an increasing trend while the level of NFATC1, c-Fos, and c-Src showed a decreasing trend with the increase of burn area.

Effects of three kinds of bacteria on DIGIRR signaling pathway in the Chinese Sturgeon (Acipenser sinensis)

Double Ig IL-1R related molecule (DIGIRR), myeloid differentiation factor 88 (MyD88), interleukin-1 receptor-associated kinase-1 (IRAK-1), tumor necrosis factor receptor-associated factor 6 (TRAF6), and Interferon-c (IFNc), are all signaling molecules involved in Toll-like receptor (TLR)-dependent inflammation. In this study, Chinese sturgeon DIGIRR, MyD88, IRAK1, TRAF6, and IFNc expression levels in immune tissues (blood, spleen, liver, head kidney and middle kidney) were upregulated in response to Citrobacter freundii infection. DIGIRR were highest in the head kidney, MyD88, IRAK1 and TRAF6 were highest in the liver, and IFNc were highest in the blood, respectively. The expression levels of DIGIRR and other genes sturgeons challenged with Plesiomonas shigelloides were similar to those challenged with C. freundii, except that DIGIRR expression was highest in the liver. Surprisingly, the expression levels of the genes after Mycobacterium marinum challenge decreased significantly, DIGIRR, MyD88, IRAK1 were lowest in the liver, TRAF6 were lowest in the blood and IFNc were lowest in the head kidney, respectively. Taken together, the expression levels of DIGIRR and other genes in Chinese sturgeon were upregulated significantly after challenge with C. freundii and P. shigelloides, but decreased significantly by M. marinum. Although their reactions varied, these findings indicate that the DIGIRR signaling pathway in Chinese sturgeon is involved the inflammatory response to diverse bacterial infection.

Randomized, double-blind, placebo-controlled trial to examine the safety, pharmacokinetics and effects of Epimedium prenylflavonoids, on bone specific alkaline phosphatase and the osteoclast adaptor protein TRAF6 in post-menopausal women

BackgroundFragility fractures due to menopausal osteoporosis are a major cause of morbidity and mortality. Osteoporotic medications have substantial side effects that limit long term use. HypothesesIngestion of a purified extract of Epimedium spp. (EP) is safe, can increase serum levels of prenylflavonoid metabolites, exert positive changes in bone specific alkaline phosphatase (BSAP), suppress of tumor necrosis factor receptor associated factor 6 (TRAF6) protein in osteoclast-precursor monocytes in peripheral blood and therefore have the potential to reduce post-menopausal bone loss. Study design & methodsHealthy postmenopausal women were randomized in a double-blind fashion to consume either EP prenylflavonoid extract (740 mg daily) or placebo daily for 6 weeks. The main outcome measures were safety and pharmacokinetics of EP flavonoids. Fasting blood was collected at 3- and 6-weeks, and two weeks after stopping medication for safety evaluations and measurement of BSAP. Peripheral blood monocytes were harvested for measurement of TRAF6 levels. Serum levels of the EP metabolites icariin, icariside I & II, icaritin and desmethylicaritin were measured using tandem mass spectrometry, and non-compartmental pharmacokinetic analyses performed using WinNonlin software. ResultsBetween October 2018 and Jun 2020, 58 postmenopausal women, aged 57.9 ± 8.9 years, were randomized and completed the study. Consumption of EP prenylflavonoids was not associated with any significant adverse symptoms, with no changes in hepatic, hematological, and renal parameters observed. The main metabolites detected in sera after ingestion of EP prenylflavonoid capsules were desmethylicaritin, icaritin and icariside II. Icariin and icariside I were below detection levels. Ingestion of EP prenylflavonoids induced a median Cmax and AUC0→∞ for desmethylicaritin of 60.9 nM, and 157.9 nM ×day, respectively; and were associated with higher levels of BSAP (p < 0.05) and a trend (p = 0.068) towards lower levels of TRAF6 in peripheral blood monocytes eight weeks after commencing prenylflavonoid ingestion. Prenylflavonoid metabolites were not detected in the sera of placebo participants. ConclusionsDespite the widespread consumption of EP extracts, the safety, mechanisms of action of their bioactive compounds, and therapeutic indications in humans are unknown. Daily consumption of EP prenylflavonoids for six weeks was safe. The predominant metabolite in sera was desmethylicaritin. Rise in prenylflavonoid metabolites was associated with higher levels of the bone anabolic marker BSAP, suggesting potential therapeutic value for post-menopausal osteoporosis.

Effect of moxibustion at "Zusanli"(ST36) and "Shenshu"(BL23) on miR-155-mediated TLR4/NF-κB signaling involving amelioration of synovitis in rheumatoid arthritis rats

To explore the effect of moxibustion at "Zusanli"(ST36) and "Shenshu"(BL23) on synovitis, and expressions of miR-155, Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), interlukine（IL-1） receptor-associated kinase (IRAK1), tumor necrosis factor receptor-associated factor 6 (TRAF6), nuclear factor κB (NF-κB), IL-1β, tumor necrosis factor receptor (TNF)-α and IL-6 mRNA and protein of synovial membrane in rheumatoid arthritis (RA) rats, so as to explore its mechanism underlying improvement of RA. A total of 48 male Wistar rats were randomly divided into normal control, model, moxibustion and antagonist groups (n=12 rats in each group). The RA model was replicated by placing the rats in a wind, cold and wet environment and injection of Freund's complete adjuvant (CFA, 0.5 mL) into the right hindlimb foot plantar. Moxibustion was applied to bilateral ST36 and BL23 for 30 min, once daily for 21 consecutive days. Rats of the antagonist group was treated by injection of TLR4 antagonist (TAK-242, 1 mg/mL, 0.1 mg/kg) via tail vein, once per day for consecutive 21 d. The joint swelling degree (JSD) and arthritis index (AI, red swelling scale) were determined, and the expression levels of various indicators of miR-155, and TLR4, myeloid MyD88, IRAK1, TRAF6, NF-κB, IL-1β, TNF-α and IL-6 mRNA and protein were assayed by quantitative real time-PCR and Western blot, separately. Compared with the normal control group, the JSD and AI, and the expression levels of synovial miR-155, TLR4, MyD88, IRAK1, TRAF6, NF-κB, IL-1β, TNF-α and IL-6 mRNA and protein were significantly increased in the model group (P<0.01). Compared with the model group, the increased levels of JSD and AI, and the expression levels of synovial miR-155, TLR4, MyD88, IRAK1, TRAF6, NF-κB, IL-1β, TNF-α and IL-6 mRNA and protein were notably down-regulated in both moxibustion and antagonist groups (P<0.01). The effects of moxibustion were evidently superior to the antagonist in down-regulating the abovementioned indexes (P<0.01), except TLR4 mRNA and protein. Moxibustion at ST36 and BL23 can reduce the synovitis of RA rats, which is related to its effects in suppressing the expressions of miR-155, TLR4, MyD88, IRAK1, TRAF6, NF-κB, IL-1β, TNF-α and IL-6 mRNA and protein (i.e., inhibition of miR-155/TLR4/NF-κB signaling).

Knockdown of TRAF6 inhibits chondrocytes apoptosis and inflammation by suppressing the NF-κB pathway in lumbar facet joint osteoarthritis.

Tumor necrosis factor receptor-associated factor 6 (TRAF6), a regulator of NF-κB signaling, has been discovered recently to be probably related to osteoarthritis, while the function of TRAF6 in lumbar facet joint osteoarthritis(FJOA)still remains unknown. The aim of this study was to probe the specific function of TRAF6 in chondrocytes and its connection with the pathophysiology of FJOA. We found upregulation of TRAF6 in FJOA cartilage by western blot analysis. In vitro, we stimulated immortalized human chondrocytes by LPS to establish the cells apoptosis model. Western blot analysis demonstrated that levels of TRAF6 and cleaved caspase-3/8 in the chondrocyte injury model increased significantly. Knockdown of TRAF6 suppressed the expression of matrix metallopeptidase-13 (MMP-13) and interleukin-6 (IL-6) induced by LPS, and alleviated cell apoptosis. Meanwhile, western blot and immunofluorescent staining demonstrated that IκBα degradation and p65 nuclear transportation were also inhibited, revealing that knockdown of TRAF6 suppressed activation of the NF-κB pathway in LPS-induced chondrocytes apoptosis model. Collectively, our findings suggest that TRAF6 plays a crucial role in FJOA development by regulating NF-κB signaling pathway. Knockdown of TRAF6 may supply a potential therapeutic strategy for FJOA.

NOD-like receptor X1, tumor necrosis factor receptor-associated factor 6 and NF-κB are associated with clinicopathological characteristics in gastric cancer.

Gastric cancer (GC) is a common cancer worldwide and its precise mechanism is largely unknown. The aim of the present study was to evaluate the expression levels of NOD-like receptor X1 (NLRX1), tumor necrosis factor receptor-associated factor 6 (TRAF6) and NF-κB in GC and normal gastric tissue samples to determine the association with the clinicopathological features of GC. GC and adjacent normal gastric tissues from 60 patients with GC were analyzed using immunohistochemistry and western blotting analysis. In addition, the association between NLRX1, TRAF6 and NF-κB expression levels were investigated by Spearman's correlation analysis. The results revealed that NLRX1 protein expression levels were downregulated in the GC tissues compared with the normal gastric tissues (P<0.05). Conversely, TRAF6 and NF-κB protein expression levels were upregulated in the GC tissues compared with the normal gastric tissues (P<0.05). A significant difference was identified between GC patients with high and low expression levels of each protein in the tumor size, vascular invasion, neural invasion, lymph node metastasis, differentiation, gross stage and clinical stage. In addition, a negative correlation was observed between NLRX1 and TRAF6, and NLRX1 and NF-κB expression levels, while a positive correlation was observed between TRAF6 and NF-κB expression levels. In conclusion, NLRX1 expression levels were discovered to be downregulated in GC tissues. The expression levels of NLRX1, TRAF6 and NF-κB were also significantly associated with the clinicopathological characteristics of GC, and the aforementioned results indicated that NLRX1 may be a biomarker in assessing GC.

Toll-like receptor signaling is changed in ovine lymph node during early pregnancy.

Toll-like receptors (TLRs) participate in regulation of adaptive immune responses, and lymph nodes play key roles in the initiation of immune responses. There is a tolerance to the allogenic fetus during pregnancy, but it is unclear that expression of TLR signaling is in ovine lymph node during early pregnancy. In this study, lymph nodes were sampled from day 16 of nonpregnant ewes and days 13, 16, and 25 of pregnant ewes, and the expressions of TLR family (TLR2, TLR3, TLR4, TLR5 and TLR9), adaptor proteins, including myeloid differentiation primary-response protein 88 (MyD88), tumor necrosis factor receptor associated factor 6 (TRAF6), and interleukin-1-receptor-associated kinase 1 (IRAK1), were analyzed through real-time quantitative polymerase chain reaction, Western blot, and immunohistochemistry analysis. The results showed that mRNA and protein levels of TLR2, TLR3, TLR4, TRAF6, and MyD88 were upregulated in the maternal lymph node, but TLR5, TLR9, and IRAK1 were downregulated during early pregnancy. In addition, MyD88 protein was located in the subcapsular sinus and lymph sinuses. Therefore, it is suggested that early pregnancy induces changes in TLR signaling in maternal lymph node, which may be involved in regulation of maternal immune responses in sheep.

The early stage of pregnancy modulates toll-like receptor signaling in the ovine liver

ABSTRACT Toll-like receptors (TLRs) participate in maternal immune regulation at multiple maternal-fetal interfaces. The liver is crucial for innate and adaptive immunity during pregnancy. The objective of this study was to measure the expression of genes and proteins related to TLR signaling. In this study, livers were obtained from ewes on day 16 of the estrous cycle, and on days 13, 16 and 25 of gestation, and RT-qPCR, western blot and immunohistochemistry were employed to measure the expression of genes and proteins related to TLR signaling, including TLR2, TLR3, TLR4, TLR5, TLR7, TLR9, myeloid differentiation primary-response protein 88 (MyD88), tumor necrosis factor receptor associated factor 6 (TRAF6) and interleukin-1-receptor-associated kinase 1 (IRAK1). Our data showed that the expression levels of TLR2, TLR3, TLR5, TLR9 and TRAF6 were increased, but those of TLR4 and TLR7 were decreased in the liver during early pregnancy. In addition, the expression levels of MyD88 and IRAK1 were the highest on days 13 and 16 of pregnancy, respectively, and the MyD88 protein was located in endothelial cells of proper hepatic arteries and portal veins and in hepatocytes. In conclusion, early pregnancy modulates TLR signaling in the maternal liver in sheep, which may participate in maternal immune regulation.

Early pregnancy affects expression of Toll-like receptor signaling members in ovine spleen.

Toll-like receptors (TLRs) are involved to the maternal immune tolerance. The spleen is essential for adaptive immune reactions. However, it is unclear that early pregnancy regulates TLR-mediated signalings in the maternal spleen. The purpose of this study was to investigate the effects of early pregnancy on expression of TLR signaling members in the ovine spleen. Ovine spleens were collected at day 16 of the estrous cycle, and at days 13, 16 and 25 of pregnancy (n = 6 for each group). Real-time quantitative PCR, western blot and immunohistochemistry analysis were used to detect TLR signaling members, including TLR2, TLR3, TLR4, TLR5, TLR7, TLR9, myeloid differentiation primary-response protein 88 (MyD88), tumor necrosis factor receptor associated factor 6 (TRAF6) and interleukin-1-receptor-associated kinase 1 (IRAK1). The results showed that expression levels of TLR2, TLR4 and IRAK1 were downregulated, but expression levels of TLR3, TLR5, TLR7, TLR9, TRAF6 and MyD88 were increased during early pregnancy. In addition, MyD88 protein was located in the capsule, trabeculae and splenic cords of the maternal spleen. This paper reports for the first time that early pregnancy has effects on TLR signaling pathways in the ovine spleen, which is beneficial for understanding the maternal immune tolerance during early pregnancy.