Effects of renal denervation on inflammatory factors in a rabbit model of early atherosclerosis

AIM: To evaluate the effects of renal denervation (RDN) on the expression of tumor necrosis factor-α (TNF-α), interleukin-1α (IL-1α) and interleukin-6 (IL-6) in a rabbit model of early atherosclerosis. METHODS: New Zealand male rabbits were divided into control group, RDN+ high-fat diet (HFD) group (RDN group), sham+HFD group (sham group) and HFD group. The rabbits in later 3 groups were fed with 2% cholesterol for 8 weeks to establish an early atherosclerosis model. The blood samples were collected to test the levels of lipids, norepinephrine (NE), TNF-α, IL-1α and IL-6. The protein expression of angiotensin Ⅱ (Ang Ⅱ) was detected by the method of immunohistochemistry. The levels of nuclear factor-κB (NF-κB) and Ang II 1 type receptor (AT1R) were evaluated by Western blot. The mRNA expression of TNF-α, IL-1α and IL-6 was determined by real-time PCR. RESULTS: After 1 d of RDN procedure, the NE level was lower in RDN group than that in sham group (P<0.01). After 8 weeks, the NE level was lower in RDN group than that in sham group and HFD group (P<0.05), and triglyceride (TG) was lower in RDN group than that in HFD group (P<0.05). The protein expression of Ang II was decreased in RDN group compared with sham group and HFD group (P<0.01). The protein expression of NF-κB was lower in RDN group than that in sham group (P<0.05). The plasma levels of TNF-α and IL-1α were reduced in RDN group compared with sham group and HFD group (P<0.05). The mRNA expression of TNF-α, IL-1α and IL-6 was reduced in RDN group compared with sham group (P<0.05). CONCLUSION: RDN inhibits sympathetic activity, decreases the plasma level of TG, and alleviates inflammatory reactions in the rabbits with atherosclerosis.     

Effect of azithromycin on airway inflammation and airway mucus hypersecretion in rats with chronic obstructive pulmonary disease

AIM: To observe the effect of azithromycin on the rats with chronic obstructive pulmonary disease (COPD), and to explore the underlying mechanism about the airway inflammation and mucus hypersecretion. METHODS: Male SD rats were randomly divided into normal control group, COPD model group, azithromycin treatment group. The COPD model was established by the method of cigarette smoking combined with intratracheal injection of LPS. Pathological changes of the bronchi and lung tissues of the rats were observed with HE staining. Pulmonary ventilation function in the rats was detected with pulmonary function instrument. The levels of IL-8, IL-17 and TNF-α in bronchoalveolar lavage fluid (BALF) were measured by ELISA. The expression of MUC5ac and TLR4 at mRNA and protein levels in bronchi and lung tissues was determined by real-time PCR and Western blot.RESULTS: HE staining showed that the changes of bronchi and lung tissues in model group were consistent with typical pathological manifestations of COPD. Compared with model group, these changes were alleviated in treatment group. The pulmonary functions in model group were significantly decreased compared with control group. The levels of IL-8, IL-17 and TNF-α in the BALF in model group were significantly increased compared with control group (P <0.05). The expression of MUC5ac and TLR4 at mRNA and protein levels in model group was significantly higher than that in control group (P <0.05). Compared with model group, the degree of the descent in pulmonary function in treatment group was significantly lessened. Compared with model group, the levels of IL-8, IL-17 and TNF-α in treatment group were significantly inhibited (P <0.05). Furthermore, the expression of MUC5ac and TLR4 at mRNA and protein levels in treatment group was significantly lower than that in model group (P <0.05). CONCLUSION: Azithromycin decreases the levels of IL-8, IL-17 and TNF-α in the BALF of COPD model rats, inhibits the protein expression of MUC5ac and TLR4 in the lung tissues, thus playing a preventive and therapeutic role to reduce airway inflammation and airway mucus hypersecretion.     

Effects of tripterygium glycosides combined with dexamethasone on TLRs/NF-κB signaling pathway in EAE rats

AIM: To investigate the role of TLRs/NF-κB pathway in experimental allergic encephalomyelitis (EAE) rats treated with tripterygium glycosides (TG) + dexamethasone (DX). METHODS: Lewis rats were used in the study and divided into control group, EAE model group, therapy 1 group (EAE rats treated with DX) and therapy 2 group (EAE rats treated with DX+TG). The mean clinical score of the rats was determined. The expression of TLR4 and TLR9 at mRNA and protein levels was detected by the methods of real-time quantitative RT-PCR and immunohistochemistry. The protein level of NF-κB p65 was also measured. The levels of TNF-α, IL-1β and IL-6 were assayed by ELISA. RESULTS: The mean clinical scores at 5th, 16th and 20th day were lower in therapy 1 group and therapy 2 group than that in EAE model group. The mean clinical score in therapy 2 group was even lower than that in therapy 1 group. At the 16th day (the peaking period), the mRNA expression of TLR4 and TLR9 in therapy 1 group and therapy 2 group were obviously lower than that in EAE model group. The protein levels of TLR4, TLR9 and NF-κB p65 were also significantly lower in therapy 1 group and therapy 2 group than those in EAE model group at peak stage of EAE. The levels of TNF-α, IL-1β and IL-6 were lower in therapy1 group and therapy2 group than those in EAE model group. The significant differences of the mean clinical score, the mRNA expression of TLR4 and TLR9, the positive ratio of NF-κB p65 and the levels of TNF-α, IL-1β and IL-6 between therapy 1 group and therapy 2 group were found. The result of orthogonal factorial analysis of variance indicated that the difference of therapeutic effect between DX and DX+TG was significant (F=75.749, P<0.01). CONCLUSION: The TLRs/NF-κB pathway takes part in the pathological process of EAE. TG combined with DX alleviates the symptoms of EAE by suppressing inflammatory and immunological reactions of EAE.     

Effects of imidapril on blood gas,oxidative stress and inflammatory factors in rats with acute lung injury induced by ammonium chloride

AIM: In this study, the rat lung injury model was induced by ammonium chloride for studying the effect of imidapril on blood gas, serum TNF-α, IL-6 and MDA concentrations, and AngⅡ and CD54 protein expression in rat lung tissue. METHODS: Male rats were randomly divided into 3 groups: control group, lung injury model group and drug group. The rats in control group were given saline (2 mL/kg), while the rats in lung injury model group were given 6% ammonium chloride (2 mL/kg). In drug group, imidapril (3 mg·kg^-1·d^-1) was given to the rats once daily for 1 week by intragastric gavage after given 6% ammonium chloride. On the 7th day, the rats were anesthetized with 2% so-dium pentobarbital. Abdominal aorta blood, venous blood and lung tissue were collected. The blood gas indexes and serum TNF-α, IL-6 and MDA concentrations were determined. The lung tissues were fixed and sliced, and the expression of AngⅡ and CD54 proteins was detected by immunohistochemistry. RESULTS: The PaCO₂ increased in lung injury model group compared with control group and drug group (P < 0.05).The expression of AngⅡ and CD54, and the concentrations of TNF-α, IL-6 and MDA also increased significantly (P < 0.01) in model group. Pulmonary edema, inflammation, alveolus congestion, hemorrhage and hyperplasia in model group were obvious compared with control group and drug group. CONCLUSION: Imidapril improves blood gas indexes, and reduces lipid peroxidation and inflammatory responses in the rats with lung injury induced by ammonium chloride.     

Hypoxia-inducible factor-1α attenuates myocardial inflammatory injury induced by ischemia and reperfusion in rats

AIM:To investigate the role of hypoxia-inducible factor-1α (HIF-1α) stable expression in myocardial inflammatory injury induced by ischemia and reperfusion (I/R) in rats. METHODS:Male Wistar rats were randomly divided into 4 groups:sham operation (sham) group, I/R group, HIF-1α stabilizer dimethyloxalyl glycine (DMOG)+I/R group and HIF-1α inhibitor YC-1+I/R group. The protein expression of myocardial Toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) was determined by Western blot. The mRNA levels of interleukin (IL)-1β, tumor necrosis factor-α (TNF-α), IL-6, TLR4 and NF-κB were detected by real-time PCR. The myeloperoxidase (MPO) activity in the myocardial tissues was measured. HE staining was used to observe the infiltration of inflammatory cells. RESULTS:HIF-1α decreased the infiltration of inflammatory cells, the MPO activity, and the mRNA levels of inflammatory factors IL-1β, IL-6 and TNF-α in the myocardial tissues. HIF-1α also reduced the expression of TLR4 and NF-κB at mRNA and protein levels (P<0.05). CONCLUSION:The stable expression of HIF-1α has an anti-inflammatory effect on the myocardial tissues after I/R injury in rats. The mechanism may be related to the inhibition of TLR4/NF-κB signaling pathway.     

Effects of apelin-13 on oxidative stress induced by high uric acid in adipocytes

AIM: To study the effects of apelin-13 on oxidative stress induced by high uric acid in 3T3-L1 adipocytes and its underlying mechanisms. METHODS: 3T3-L1 adipocytes were stimulated with uric acid at 10 mg/dL for 48 h. Some of the adipocytes were administered with 1 μmol/L apelin-13 in the presence of uric acid at 10 mg/dL. The adipocytes stimulated with 100 μmol/L H₂O₂ were served as positive controls. The intracellular reactive oxygen species (ROS) concentrations were detected by flow cytometry. The biochemical kits were used to measure the activities of superotide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and NADPH oxidase (NOX) activity, and the content of malondialdehyde (MDA) in the cell lysate and the supernatant. The mRNA levels of renin-angiotensin system (RAS) components, including angiotensinogen (AGT), angiotensin-converting enzyrne1 (ACE1), angiotensin II type 1 receptor (AT1R) and AT2R, as well as angiotensin II receptor -like 1 (APJ) were measured by real-time PCR. The concentrations of angiotensin II (AngⅡ) in the cell lysate and the supernatant were measured by ELISA. RESULTS: Adipocytes stimulated with uric acid at 10 mg/dL had lower activities of antioxidant enzymes (SOD, GSH-PX and CAT) and higher levels of NOX activity and MDA content (P < 0.05). Accordingly, the intracellular ROS levels were found to be dramatically increased. However, apelin-13 administration attenuated uric acid-induced oxidative stress in the 3T3-L1 adipocytes. Uric acid at 10 mg/dL upregulated the mRNA expression of local RAS, enhanced AngⅡ concentrations both in the cell lysate and the supernatant, and down-regulated the mRNA level of APJ in the adipocytes (P < 0.05). Conversely, apelin-13 partially reversed these parameters. CONCLUSION: Apelin-13 attenuates oxidative stress induced by uric acid, may be via down-regulation of local RAS expression in the 3T3-L1 adipocytes.     

Effects of dexamethasone on acute lung injury by inhibiting renin-angiotensin system in rats

AIM:To explore the relationship between renin-angiotensin system (RAS) and acute lung injury (ALI) in rats, and the effect of dexamethasone (DEX) on RAS was observed.METHODS: The rat model of ALI was induced by hemorrhagic shock and LPS administered intraperitoneally. The changes of MAP and the effects of DEX on MAP were observed. The mRNA expressions of ACE, AGT, AT1 and AT2 in lung tissue were assayed by RT-PCR. The changes of Ang I and Ang II in the serum and the effects of DEX on them were observed.RESULTS: The increasing of MAP was statistically obvious. MAP in hemorrhagic shock+LPS (HL) group recovered more slowly than that in HL+DEX(HLD) group. ACE, AGT, AT1 and AT2 mRNA expressions in HL group were increased, and higher than those in HLD group. The change of Ang II in serum in HL group was obviously higher than that in HLD group, while that of Ang I was not obvious.CONCLUSION:ALI activates RAS in rat lung, and promotes the production of Ang II then aggravates the injury of lung through increasing the expression of ACE and AGT. DEX decreases expression of Ang II.     

Role of FAT/CD36 in high-fat diet-induced adipose tissue inflammation

AIM: To investigate the role of fatty acid translocase/CD36 (FAT/CD36) in adipose tissue inflammation induced by a high-fat diet. METHODS: C57BL/6J mice were fed with a normal-chow diet (NCD) or a high-fat diet (HFD) for 14 weeks. The content of free fatty acid (FFA) in the serum was measured by ELISA. The expression of CD36, cytokines and chemokines at mRNA and protein levels in the adipose tissues was determined by real-time polymerase chain reaction and Western blotting. Immunohistochemical staining was used to examine the macrophages infiltration in the adipose tissues. The inflammatory responses in CD36 knockout mice and wild type mice with high-fat diet were analyzed. RESULTS: The levels of FAT/CD36 were higher in HFD group than that in NCD group. HFD feeding enhanced the mRNA and protein expression of IL-1β, IL-6, TNF-α, MCP-1 and MIP-1, as well as promoted macrophage infiltration in the adipose tissues. Interestingly, as fed with HFD, the expression of cytokines/chemokines and macrophage infiltration were significantly reduced in adipose tissues of the CD36 knockout mice, compared with the wild type mice. CONCLUSION: High-fat diet promotes adipose tissue inflammation in the mice in a FAT/CD36-dependent manner.     

Effects of bFGF on brain edema,nerve function injury and autophagy related protein in rats with traumatic brain injury

AIM:To study the effects of basic fibroblast growth factor (bFGF) on brain edema, nerve function damage and autophagy related proteins in rats with head injury. METHODS:The rat model of craniocerebral injury (CI) was constructed. The rats were divided into control group, CI group, and low-, middle-and high-dose bFGF groups (n=10). The CI model was established in CI group, while the rats in control group were not given epidural impact. The rats in low-dose, middle-dose and high-dose bFGF groups were given bFGF at 2, 4 and 6 μg, respectively, by intraperitoneal injection after 30 min. The neurological function in the rats was evaluated by improved neurological function scoring. The rat brain tissues were taken, and the water content was detected. The levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-1β in the brain tissue were measured by ELISA. The malondialdehyde (MDA) content was analyzed by thiobarbituric acid method. The activity of superoxide dismutase (SOD) was examined by WST-8 assay. The glutathine peroxidase (GSH-Px) activity was detected by colorimetric method. The protein levels of autophagy related proteins LC3-Ⅱ and beclin-1 in the brain tissues were determined by Western blot. RESULTS:The neurological function score was increased significantly of the rats in CI group. The rat model of craniocerebral injury was successfully constructed. Neurological function scores in the rats in low-dose, middle-dose and high-dose bFGF groups were reduced, the water content of the brain tissue was also reduced (P<0.05). The levels of TNF-α, IL-6 and IL-1 β were decreased in the brain tissues (P<0.05), the content of MDA was declined (P<0.05), the activities of SOD and GSH-Px were increased (P<0.05), the protein levels of LC3-Ⅱ and beclin-1 were decreased, compared with the untreated rats in CI group (P<0.05). CONCLUSION:bFGF improves the nerve function of the rats with craniocerebral injury, reduces the water content of the brain tissue, reduces the expression of autophagic protein LC3-Ⅱ and beclin-1.The mechanism is related to the inhibition of inflammatory reaction and oxidative damage.     

Effects of Huaiyu decoctum on serum concentrations of TNF-α, IL-6 and IL-10 in rats after anorectal operation

ATM: To investigate the effects of Huaiyu decoctum on the serum concentrations of TNF-α, IL-6 and IL-10 in rats after anorectal operation. METHODS: Sprague-Dawley rats (n=40) were randomly divided into 4 groups:normal group, model group, low-dose Huaiyu decoctum group and high-dose Huaiyu decoctum group. The concentrations of TNF-α, IL-6 and IL-10 in the rat serum were measured by ELISA. The pathologic changes of the anorectal tissues were observed under microscope with HE staining. The protein expression of ICAM-1, VCAM-1 and NF-κB was determined by Western blotting. RESULTS: After Huaiyu decoctum administration, TNF-α and IL-6 concentrations in the serum were significantly decreased, and IL-10 concentration was increased as compared with model group. Moreover, Huaiyu decoctum markedly attenuated edema and hyperemia in the rats after anorectal operation. The protein expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and NF-κB in the anorectal tissues was obviously inhibited by Huaiyu decoctum treatment. CONCLUSION: Huaiyu decoctum improves the recovery of anorectal tissues after operation by decreasing the serum concentrations of TNF-α, IL-6 and IL-10, and reducing the protein expression of ICAM-1, VCAM-1 and NF-κB in the anorectal tissues.     

Angiotensin 1-7 attenuates angiotensin Ⅱ-induced human glomerular endothelial cell injury via Mas receptor

AIM:To investigate the effect of angiotensin 1-7 (Ang1-7) on the human glomerular endothelial cells (HGECs) injury induced by angiotensin Ⅱ (Ang Ⅱ) and its possible mechanism. METHODS:Cultured HGECs were divided into 6 groups randomly:control group, Ang Ⅱ group, Ang1-7 group, Ang Ⅱ +Ang1-7 group, Ang Ⅱ +Ang1-7+A779 (an inhibitor of Mas receptor) group and A779 group. The apoptotic rate and reactive oxygen species (ROS) of HGECs were analyzed by flow cytometry and photographed by fluorescence microscopy. The levels of lactate dehydrogenase (LDH), nitric oxide (NO), endothelin-1 (ET-1), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), monocyte chemoattractant protein-1 (MCP-1) and intercellular adhesion molecule-1 (ICAM-1) in the supernatant of cell cultures were measured. RESULTS:Compared with the control group, the apoptotic rate and the average fluorescence intensity of ROS were increased in the Ang Ⅱ group, IL-6, TNF-α, TGF-β, ICAM-1 and MCP-1 in cell supernatants were also increased in the Ang Ⅱ group (P<0.05). Compared with the Ang Ⅱ group, the apoptotic rate, ROS level, and the above inflammatory factors were decreased in Ang Ⅱ +Ang1-7 group (P<0.05). Compared with the Ang Ⅱ +Ang1-7 group, adding A779 increased the cell apoptotic rate, ROS production and the releases of the above inflammatory factors in cell supernatants (P<0.05). Compared with the Ang Ⅱ group, adding Ang1-7 inhibited the LDH leakage, ET-1 secretion and promoted the release of NO in a dose-dependent manner (P<0.05). CONCLUSION:Ang1-7 attenuates the HGECs injury induced by Ang Ⅱ by inhibiting the Mas receptor.     

Expression of calprotectin in rats with renal ischemia-reperfusion injury

AIM: To investigate the expression of calprotectin(CALP) in the rats with renal ischemia-reperfusion injury(IRI). METHODS: Male Sprague-Dawley rats were randomly divided into sham operation and IRI group(n=25 in each group). Blood samples and the kidneys were obtained at 6 h, 12 h, 24 h, 48 h and 72 h after reperfusion. The pathological changes of the kidneys were observed. The serum concentrations of blood urea nitrogen(BUN) and serum creatinine(SCr) were measured. The serum levels of CALP, tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6) were detected by ELISA, and the expression of CALP, Toll-like receptor 4(TLR4) and NF-κB p65 in the renal tissues were determined by the methods of immunohistochemistry and Western blot. RESULTS: Different serial ischemia changes were observed in the renal tissues, mainly in the renal tubular epithelial cells and the mesenchyma, with the infiltration of inflammatory cells. The serum levels of BUN, SCr, CALP, TNF-α and IL-6 in IRI group were markedly increased as compared with sham group(P<0.05). The protein expression of CALP, TLR4 and NF-κB p65 in the renal tubular epithelial cells in IRI group was greatly enhanced in comparison with that in sham group(P<0.05). CONCLUSION: The serum concentrations of CALP, TNF-α and IL-6, and the protein expression levels of CALP, TLR4 and NF-κB p65 in the renal tissue are significantly increased in the rats with IRI, suggesting that calprotectin plays an important role in the inflammation in rats with IRI.     

Protective effects of sequoyitol on type 2 diabetic rats with liver inflammatory lesions

AIM：To investigate the possible protective effect of sequoyitol on type 2 diabetic rats with liver inflammatory lesions. METHODS：Type 2 diabetic rats were induced by feeding high-fat/high-sugar diet and injecting with a low dose of streptozotocin. Sequoyitol at doses of 12.5, 25 and 50 mg·kg-1·d-1 was orally administered in the model rats. At the end of the experiment, the rats were sacrificed. Serum levels of fasting blood glucose, alanine aminotransferase(ALT), aspartate aminotransferase(AST) and albumin(ALB) were determined. Liver wet was recorded and liver index was calculated. The levels of C-reactive protein(CRP),tumor necrosis factor α(TNF-α) and interleukin 6(IL-6) in the liver tissues were also measured. Real-time PCR was used to determine the mRNA expression of TNF-α. In addition, the pathological changes of the liver were observed with HE staining. RESULTS：Compared with the model rats, treatment with sequoyitol obviously decreased the levels of fasting blood glucose, ALT, AST, ALB, CRP, TNF-α and IL-6, reduced the liver index, down-regulated the mRNA expression of TNF-α in the liver, and ameliorated the pathologic changes of the liver. CONCLUSION：Sequoyitol attenuates liver lesions in type 2 diabetic rats through down-regulation of TNF-α and IL-6 expression.     

Propofol inhibits LPS-induced inflammatory response in microglia via TRPV1 ion channels

AIM:To investigate the effects of propofol (P) on the inflammatory response of microglia induced by lipopolysaccharide (LPS) and the mechanisms. METHODS:Mouse microglia BV2 cells were treated with LPS at 100 μg/L to establish a neuroinflammatory injury model. The BV2 cells were divided into 4 groups:control group (C group), model group (L group), L+P group and LPS+AMG517 group (L+A group). The level of tumor necrosis factor-α (TNF-α) in the cell culture supernatant was measured by ELISA. The mRNA expression of transient receptor potential cation channel subfamily V member 1 (TRPV1) was detected by real-time PCR. The protein levels of TRPV1, TNF-α, interleukin-1β (IL-1β), interleukin-6 (IL-6) and phosphorylated calcium/calmodulin-dependent protein kinase Ⅱ (p-CaMKⅡ) were determined by Western blot. The content of free Ca²⁺ in the microglia BV2 cells was detected by Fluo-3 AM assay. RESULTS:Compared with C group, the level of TNF-α was significantly increased in L group (P<0.01), but that in P group was not changed. Compared with L group, the level of TNF-α was significantly lower than that in L+P group within 4 h (P<0.01). Compared with C group, the mRNA expression of TRPV1 was significantly increased in L group (P<0.01). Compared with L group, the mRNA expression of TRPV1 was significantly down-regulated in L+P group (P<0.01).Compared with L group, the protein levels of TNF-α, IL-1β, IL-6 and p-CaMKⅡ and intracellular Ca²⁺ concentration were significantly lower than those in L+P group and L+A group (P<0.01). CONCLUSION:Propofol inhibits the inflammatory response of microglia by reducing the expression of TNF-α, IL-1 and IL-6, which may be related to the down-regulation of TRPV1 and p-CaMKⅡ and the reduction of intracellular Ca²⁺ concentration.     

Mechanism of systemic inflammatory response syndrome induced by EC DNA

AIM: To investigate whether the bacterial DNA participates in SIRS and its possible mechanism. METHODS: Escherichia coli genomic DNA (EC DNA) was extracted and purified from Escherichia coli 25922 by alkaline lysis method. Mortality of mice challenged with EC DNA and the changes of TNF-α and IL-6 in rat serum were observed. ANA-1 cells were cultured in vitro, after the cells were stimulated by different concentrations of EC DNA and LPS, the level of TNF-α and IL-6 in supernatant were tested. Meanwhile,expression of TLR9 and TLR4 on cell surface was measured. Activation of NF-JB was also observed. RESULTS: The lethal effect of EC DNA on mice with an obvious dose-effect relationship was observed. The death happened within 24 hours. Calf thymus DNA and DNase I-treated EC DNA did not lead to mice to die. The changes of serum TNF-α and IL-6 in rats induced by EC DNA and LPS were similar, but TNF-α peak level of EC DNA group appeared 1 hour earlier than that of LPS group. In vitro, large amount of TNF-α and IL-6 were released from ANA-1 cells stimulated by EC DNA. High expression of TLR9 and TLR4 was observed on surfaces of THP-1 cells. In particularly, LPS induced strong activation of NFκB. The results suggested other pathway possibly took part in the signal transduction inducea by EC DNA. CONCLUSION: EC DNA has the abilities to lead to death of mice, andinduces serum TNF- αand IL- 6 level to increase in rats and ANA- 1 cells to release cytokines in vitro. High expression of TLR9 and TLR4, strong activation of NF- κB may be its importantmolecular mechanism, but other pathway probably exists to play an important role.     

Protective effects of taurine on LPS-induced myocardial damage in rats

AIM: To investigate the effects of taurine on lipopolysaccharide (LPS)-induced myocardial damage in rats. METHODS: Healthy male SD rats (n=30) were randomly divided into control group (CON), LPS model group (LPS) and taurine treatment group (TAU). The rats in CON group and LPS group were intravenously injected with normal saline, and the rats in TAU group were injected with taurine (100 mg/kg). After 2 h, the rats in LPS group and TAU group were intraperitoneally injected with LPS at 10 mg/kg, and the rats in CON group were injected with normal saline. Six hours after injection of LPS, the blood samples were collected for determination of superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, and tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) levels. The myocardial tissues were processed for histological examination and the analysis of Western blot. RESULTS: Compared with CON group, LPS significantly reduced SOD activity in the serum and heme oxygenase 1 (HO-1) protein expression in the myocardial tissues, increased the serum content of MDA and levels of TNF-α and IL-6. LPS also significantly elevated the levels of TNF-α and IL-6, and up-regulated the cyclooxygenase-2 (COX-2) expression and phosphorylation of nuclear factor kappa B (NF-κB) in the myocardial tissues. Taurine pretreatment significantly elevated SOD activity and HO-1 protein expression level, decreased the levels of COX-2, TNF-α, IL-6 and phosphorylated NF-κB. Histological observation showed that taurine reduced inflammatory response in the myocardial tissue. CONCLUSION: Taurine attenuates LPS-induced myocardial damage in rats. The beneficial effects of taurine may be associated with its reduction of p-NF-κB/COX-2 signaling by activation of HO-1/CO.     

Effects of AT1 receptor autoantibody on renal cell apoptosis and JNK expression in diabetic nephropathy rats

AIM:To study the effects of angiotensin Ⅱ type 1 receptor autoantibody (AT1-AA) on the apoptosis of renal cell and the expression of c-Jun N-terminal kinase (JNK) in diabetic nephropathy (DN) rats. METHODS:High-sucrose and high-fat diet and intraperitoneal injection of streptozotocin were utilized to induce DN rat model. We employed enzyme-linked immunosorbent assay (ELISA) for serum AT1-AA and TUNEL staining for renal cell apoptosis. Furthermore, Western blotting was performed to measure the levels of endoplasmic reticulum stress (ERS) chaperone glucose-regulated protein 78 (GRP78) and ERS-associated apoptosis protein p-JNK. RESULTS:The renal cell apoptotic rate in DN group was significantly increased compared with NC group, and the apoptotic renal cells in AT1-AA positive DN rats were much greater than those in AT1-AA negative DN rats (P<0.05). The protein levels of GRP78 and p-JNK were significantly increased compared with NC group. GRP78 and p-JNK protein levels also significantly increased in AT1-AA positive DN rats compared with AT1-AA negative DN rats. CONCLUSION: AT1-AA activates ERS response and induces renal cell apoptosis via the JNK apoptotic pathway in the renal tissues of DN rats.     

TNF-α induces PIP3-mediated necroptosis in MLO-Y4 cells

AIM: To explore whether tumor necrosis factor-α (TNF-α) induces necroptosis in murine long bone osteocyte-like cell line MLO-Y4 and the possible mechanism. METHODS: The MLO-Y4 cells were divided into control group, TNF-α group, TNF-α+necrostatin-1 (Nec-1) group, TNF-α+Z-VAD group and TNF-α+receptor-interacting protein 3 (RIP3)-siRNA group. The death rate of MLO-Y4 cells was assessed by flow cytometry with Annexin V-FITC/PI staining. The morphological features of the cells were observed under transmission electron microscope (TEM). The protein levels of RIP1, RIP3 and cleaved caspase-3 were determined by Western blot. Finally, the numbers of total cells and RIP1-RIP3-positive cells were observed under laser scanning confocal microscope. The production of reactive oxygen species (ROS) in the cells was measured by DCFH-DA staining. RESULTS: Compared with control group, the apoptotic or necroptotic rate of the cells induced by TNF-α was increased significantly (P<0.01). The increased apoptotic or necroptotic rate was dramatically reduced by treating with Nec-1, Z-VAD or RIP3-siRNA transfection (P<0.01). In TNF-α group and TNF-α+Z-VAD group, a lot of MLO-Y4 cells with typical necroptotic morphological features were observed under TEM. However, obvious necroptotic cells were not found in Nec-1 or RIP3-siRNA treatment group. The protein level of RIP1 in the cells treated with Nec-1 was sharply lower than that in TNF-α group (P<0.01). However, Z-VAD did not reduce the elevated levels of RIP1 and RIP3. RIP3-siRNA effectively down-regulated the protein level of RIP3 compared with TNF-α group (P<0.01). Nec-1 effectively down-regulated the protein levels of RIP1 colocalized with RIP3 compared with TNF-α group (P<0.01). However, Z-VAD did not reduce the levels of RIP1 colocalized with RIP3. Nec-1, Z-VAD and RIP3 siRNA significantly decreased the ROS levels (P<0.01). CONCLUSION: TNF-α induces the necroptosis of MLO-Y4 cells. RIP3 play vital roles in the cell necroptotic signal pathway. ROS may be the executor of necroptosis of MLO-Y4 cells.     

Effects of Radix Angelicae Sinensis on changes of IL-6, TNF-α and bFGF in renal ischemia/reperfusion injury in rabbits

AIM: To determine the effect of Radix Angelicae Sinensis(RAS) on renal ischemia/reperfusion injury in rabbits and to explore its mechanism. METHODS: Twenty-five rabbits were divided randomly into the sham operated group(Control group), renal ischemia/reperfusion injury group(IR group) and RAS+IR group. At the time point of reperfusion 48 h after renal ischemia 1 h, the renal tissue were observed by electron-microscope and the contents of creatinine(Cr) in serum, tumor necrosis factor-α(TNF-α), interleukin-6(IL-6)and basic fibroblast growth factor(bFGF) in the renal tissue were measured. RESULTS: A remarkably degenerative changes in renal tissue were showed under electronmicroscope in IR group, but the changes in RAS+IR group were slight. The contents of Cr, TNF-α and IL-6 in IR group were higher than those in Control group, these parameters in RAS+IR group were lower than those in IR group, the difference between these groups was significant(P< 0.05 or P< 0.01). At the same time, the content of bFGF in IR group was lower than that in Control group(P< 0.01), while the content of bFGF in RAS+IR group was higher than that in IR group(P< 0.01) and Control group(P< 0.05). CONCLUSION: RAS has an effect of alleviating the renal ischemia/reperfusion injury by modulating the production or release of TNF-α, IL-6 and bFGF.