Co-treatment of betulin and gefitinib is effective against EGFR wild-type/KRAS-mutant non-small cell lung cancer by inducing ferroptosis.

Clinical trials suggest that non-small-cell lung cancer (NSCLC) patients with KRAS mutations and wild-type EGFR have reduced benefits from gefitinib treatment. Ferroptosis is a new form of cell death that plays an important role in mediating the sensitivity of EGFR-TIKs. Here, we explored the antitumor ability of gefitinib in combination with betulin to overcome drug resistance through ferroptosis in wild-type EGFR/KRAS-mutant NSCLC cells. A549 and H460 cells were treated with gefitinib and betulin, and cell viability, apoptosis, and migration ability were assessed using the CCK-8 assay, flow cytometry, and wound-healing assay, respectively. Several cell death inhibitors were used to study the form of cell death. Ferroptosis-related events were detected by performing reactive oxygen species (ROS) and iron level detection, malondialdehyde (MDA) assay, and glutathione (GSH) assay. EMT-associated proteins and ferroptosis-related proteins were detected by using western blotting. A xenograft model was constructed in vivo to investigate the role of the combination treatment of betulin and gefitinib in NSCLC tumor growth. Gefitinib in combination with betulin exhibited antagonistic effects on cellular viability and induced cell apoptosis. It also induced ROS accumulation, lipid peroxidation, and GSH depletion and induced ferroptosis-related gene expression. Moreover, ferroptosis inhibitors, but not inhibitors of other forms of cell death, abrogated the effect of gefitinib in combination with betulin. Moreover, it also inhibited the tumor growth of NSCLC in vivo. Our findings suggest that gefitinib in combination with betulin is a novel therapeutic approach to overcome gefitinib resistance in EGFR wild-type/KRAS-mutant NSCLC cells by inducing ferroptosis.

[Effects of L-carnitine on autophagy and apoptosis of mouse pulmonary microvascular endothelial cells induced by lipopolysaccharide].

Objective: To investigate the protective effects of L-carnitine (LC) on lipopolysaccharide (LPS) - injured mouse pulmonary microvascular endothelial cells (PMVECs) and its effects on autophagy and apoptosis. Methods: Cultured mouse PMVECs were divided into three groups: ① Control group, ② LPS group (10 µg/ml, 3, 6, 12, 24 h), ③ LPS (10 µg/ml, 24 h)+LC (2.5, 5.0, 10 µg/ml) (LPS+LC) group. PMVECs apoptosis was examined by Annexin V-FITC/PI double labeling method. Autophagosome was detected by immunofluorescence staining. Levels of autophagy-related protein LC3 and apoptosis-related protein caspase-3 were detected by Western blot. PMVECs viability was measured by CCK-8. Results: ① Compared with the control group, LPS treatment inhibited the PMVECs viability significantly, whereas the apoptosis rate and the expression of autophagy protein LC3 II were markedly increased after LPS treatment for 6 h, 12 h and 24 h. ② Compared with LPS group (10 µg/ml, 24 h), the PMVECs viability, levels of autophagy protein LC3 II and caspase-3 protein expression as well as apoptosis rate in LPS+LC group were increased significantly. Conclusion: LC can increase the activity of PMVECs injuried by LPS, promote autophagy and inhibit apoptosis of PMVECs.

[Changes of FLI-1 protein expression in mice with pulmonary endothelial barrier dysfunction following acute lung injury induced by lipopolysaccharide].

Objective: To observe changes of Friend leukemia virus integration 1 (FLI-1) protein expression of pulmonary tissue in mice with pulmonary endothelial barrier dysfunction following acute lung injury (ALI) induced by lipopolysaccharide (LPS). Methods: The mouse model of ALI was established by injection of LPS (7.5 mg/kg, i.p. ). At 0 h, 12 h, 24 h and 48 h after LPS injection, pulmonary microvascular endothelial permeability and lung wet/dry weight ratio (W/D) were assessed. The contents of TNF-α and IL-6 in bronchoalveolar lavage fluid (BALF) were detected by ELISA method. The protein levels of FLI-1 and Src protein tyrosine kinase (SRC) were analyzed by Western blotting.Results: ①Pulmonary microvascular endothelial permeability at 12 h and 24 h were significantly higher than those of 0 h by 74.3% and 162.4%, respectively, while that of 48 h was lower than that of 24 h by 27.0% (P＜0.05). The W/D at 12 h and 24 h were significantly higher than those of 0 h by 50.1% and 122.9%, respectively, while that of 48 h was lower than that of 24 h by 10.7% (P＜0.05). ②The contents of IL-6 and TNF-α in BALF at 12 h and 24 h were significantly higher than those of 0 h, while those of 48 h were significantly lower than those of 24 h by 28.3% and 21.6% (P＜0.05), respectively. ③The protein level of FLI-1 in lung at 12 h and 24 h were down-regulated than those of 0 h by 20.4% and 56.9%, respectively, while that of 48 h was up-regulated than that of 24 h by 18.2% (P＜0.05). The protein level of SRC in lung at 12 h and 24 h were up-regulated than those of 0 h by 76.8% and 176.7%, respectively, while that of 48 h was down-regulated than that of 24 h by 33.4% (P＜0.05).④Same as the protein level of FLI-1 with the protein level of SRC in lung, pulmonary microvascular endothelial permeability was significantly negative correlated with the protein level of FLI-1 in lung, while it was significantly positive correlated with the protein level of SRC (P＜0.01). Conclusion: FLI-1 participates in the pathological proceeding of pulmonary endothelial barrier dysfunction following ALI induced by LPS.

YAP activity protects against endotoxemic acute lung injury by activating multiple mechanisms.

The roles of the Hippo­Yes­associated protein (YAP) pathway in lung injury and repair remain elusive. The present study examined the effects of systemic inhibition or stimulation of YAP activity on lung injury, repair and inflammation in a mouse model of lipopolysaccharide (LPS)­induced lung injury. Mice were treated with or without YAP inhibitor, verteporfin, or with or without YAP stimulator, XMU­MP­1, and intraperitoneally injected with LPS (7.5 mg/kg). Lung injury and repair were evaluated by histological analysis and by testing for markers of lung injury. Lung inflammation was assessed by measuring tissue levels of inflammatory mediators. Lung injury was associated with a decreased, whereas lung repair was associated with an increased YAP activity evidenced by nuclear translocation. Lung injury was associated with a high level of lung inflammation and epithelial adherens junction disassembly, but not with cell proliferation or epithelial cell regeneration. The injury phase was defined as 0­48 h post­LPS injection, and the 48­168 h time period was considered the repair phase. Inhibition of YAP activity at the injury phase, using verteporfin, exacerbated, whereas its stimulation, using XMU­MP­1, alleviated lung injury, lung inflammation and epithelial adherens junction disassembly. Inhibition or stimulation of YAP activity at the injury phase had no effects on cell proliferation or epithelial regeneration. By contrast, lung repair was associated with inflammation resolution, increased cell proliferation, epithelial regeneration and reassembly of epithelial adherens junctions. Inhibition of YAP activity at the repair phase delayed inflammation resolution, impeded lung recovery, inhibited cell proliferation and epithelial regeneration, and inhibited epithelial adherens junction reassembly. Stimulation of YAP activity at the repair phase reversed all these processes. The results of the current study demonstrated that the Hippo­YAP activity serves a protective role against endotoxemic lung injury. The Hippo­YAP activity alleviated lung inflammation and injury at the injury phase and promoted inflammation resolution and lung repair at the repair phase.

SIRT1 activation attenuates cardiac fibrosis by endothelial-to-mesenchymal transition.

Endothelial-to-mesenchymal transition (EndMT) is closely related to the pathogenesis of various diseases, including cardiac fibrosis. Transforming growth factor (TGF)-ß1 strongly induces EndMT, and sirtuin 1 (SIRT1) may play vital roles in TGF-ß/Smad pathway inhibition. This study aimed to determine whether SIRT1 activation inhibits EndMT, thereby attenuating cardiac fibrosis. Cardiac fibrosis was induced in C57BL/6 mice by subcutaneously injecting isoproterenol. SIRT1 was activated and then suppressed by intraperitoneally injecting resveratrol (RSV) and EX527, respectively. EndMT was induced by adding TGF-ß1 to H5V cells and measured by immunofluorescence and western blot. The role of SIRT1 in EndMT was determined by lentivirus-mediated overexpression of SIRT1. Interactions between SIRT1 and Smad2/3 in the TGF-ß/Smad2/3 pathway were examined by immunoprecipitation. SIRT1 activation upregulated CD31 and vascular endothelial-cadherin, and downregulated α-smooth muscle actin, fibroblast-specific protein 1, and vimentin. SIRT1 upregulated and EX527 inhibited TGF-ß receptor 1 (TGF-ßR1) and P-Smad2/3 expression, respectively. SIRT1 activation and overexpression by RSV/SRT2104 and lentivirus transfection, respectively, reduced TGF-ß1-induced EndMT. SIRT1 and Smad2/3 interaction was shown by immunoprecipitation in vivo and in vitro. TGF-ßR1 and P-Smad2/3 expression was downregulated and Smad2/3 nuclear translocation was inhibited. In conclusion, SIRT1 activated by RSV attenuated isoproterenol-induced cardiac fibrosis by regulating EndMT via the TGF-ß/Smad2/3 pathway.

[Effects of apolipoprotein E on proliferation of mouse pulmonary arterial smooth muscle cells induced by hypoxia].

OBJECTIVE: To investigate the effects of apolipoprotein E (apoE) on the proliferation of pulmonary arterial smooth muscle cells (PASMCs) induced by hypoxia. METHODS: Primary culture of mouse PASMCs was prepared from male C57BL/6 mouse pulmonary artery by the method of tissue block anchorage. PASMCs were divided into four groups: normoxia group, normoxia with apoE administration group, hypoxia group and hypoxia with apoE administration group. The proliferation of PASMCs was observed by EdU incorporation. The protein levels of apoE, proliferating cell nuclear antigen (PCNA), protein kinase C (PKC) and phosphorylated protein kinase C (p-PKC) were analyzed by Western blot. RESULTS: The percentage of PASMCs proliferation of hypoxia group was significantly higher than that of normoxia group by 64.7% (P＜0.05), and the protein expression levels of PCNA and p-PKC of hypoxia group were up-regulated than those of normoxia group by 69.0% and 120.0%, while the protein expression of apoE was down-regulated by 51.0% (P＜0.05), respectively. The percentage of PASMCs proliferation of hypoxia with apoE administration group was significantly lower than that of hypoxia group by 19.6% (P＜0.05), and the protein expression levels of PCNA and p-PKC of hypoxia with apoE administration group were down-regulated than those of hypoxia group by 19.8% and 103.2% (P＜0.05), respectively. There was no significant difference among each group in the protein expression of PKC, nor do there any significant difference between normoxia group and hypoxia group in the protein expression of p-PKC (P＞0.05). CONCLUSION: ApoE can inhibit the proliferation of PASMCs induced by hypoxia, and the mechanism of its effect may be attributed to blocking PKC pathway.

[Effect of autophagy inhibitor chloroquine on acute alcoholinduced liver disease].

OBJECTIVES: To investigate the role of autophagy inhibitor chloroquine (CQ) in acute ethanol-induced liver injury and its mechenism. METHODS: Twenty-one C57BL/6 male mice were randomly divided into three groups:control group, ethanol group, CQ + ethanol group (n=7). Mice in ethanol group were administered 33% (v/v) ethanol at a dose of 4.5 g/kg body weight. Ethanol-induced liver steatosis in each group was detected by hematoxylin and eosin staining. Hepatic lipid accumulation was detected by staining with Oil red O. Hepatic tissue triglyceride (TG) levels, serum aspartate aminotransferase(AST) and alanine aminotransferase(ALT) were determined by biochemical assays. Protein expression of microtubule-associated protein 1 light chain 3(LC3) and nuclear factorκB p65(NF-κB p65) were measured by Western blot and immunofluorescence. Pro-inflammatory factors tumor necrosis factor-α(TNF-α)、interleukin 6(IL-6) were detected by ELISA. RESULTS: Compared with control group, ethanol induced liver injury proved by accumulation of hepatic lipids, TG levels, AST and ALT activities were significantly increased by ethanol, protein expression of LC3-Ⅱ was also markedly increased by ethanol. Compared with ethanol group, addition of CQ increased furtherthe level of LC3-Ⅱexpression, and TG amount, serum AST and ALT activities, and the expression of NF-κB p65, TNF-αand IL-6. CONCLUSIONS: Acute ethanol-intake could induce liver steatosis and inflammation, and autophagy inhibitor CQ exacerbatedethanol-induced liver injury, suggested that autophagy might be protective effect in acute ethanol-induced liver disease.

[Changes of apoE protein expression in lung of mice with hypoxic pulmonary arterial hypertension].

OBJECTIVE: To observe the changes of apolipoprotein E (apoE) protein expression of pulmonary tissue in mice with pulmonary hypertension induced by hypoxia. METHODS: The animal model of hypoxic pulmonary hypertension was established by exposing the mice to isobaric hypoxic chamber for 3 weeks (23 h/d, regular chow feed).Twenty male wild type (WT) C57BL/6 mice and twenty apoE gene knockout (apoE-KO) mice were randomly divided into normoxia group and hypoxia group. The plasma concentrations of low density lipoprotein (LDL), high density lipoprotein (HDL) and total cholesterol were detected by ELISA method. The protein expression of apoE in lung and liver, and peroxisome proliferators-activated receptor gamma (PPARγ) in lung were measured by Western blot. RESULTS: ①In WT mice, the right ventricular systolic pressure (RVSP) and the weight ratio of right ventricle (RV) to left ventricle plus septum (LV+S) of hypoxia group were significantly higher than those of normoxia group by 68% and 59% (P<0.05), respectively. The plasma concentration of HDL and HDL/LDL of hypoxia group were significantly lower than those of normoxia group by 17% and 40% (P<0.05), respectively.The protein expression of apoE in lung and in liver of hypoxia group were significantly down-regulated than those of normoxia group by 48% and 52% (P<0.05), respectively.The protein expression of PPARγ in lung was significantly down-regulated than that of normoxia group by 37%(P<0.05).RVSP were significantly negative correlated with the protein levels of apoE and PPARγ in lung (P<0.01).② In apoE-KO mice, RVSP and the weight ratio of RV to LV+S of hypoxia group were significantly higher than those of normoxia group by 96% and 86% (P<0.05), respectively.RVSP and RV to (LV+S) of hypoxia group in apoE-KO mice were significantly higher than those of hypoxia group in WT mice by 29% and 24% (P<0.05), respectively. CONCLUSIONS: Down-regulated expression of apoE in lung tissue participates in the pathological proceeding of pulmonary hypertension induced by hypoxia.

[Apelin attenuates hypoxia induced pulmonary hypertension of mice through regulation of lipid metabolism].

OBJECTIVE: To observe the role of apelin in the prevention of pulmonary hypertension induced by hypoxia in mice. METHODS: Adult male apoE gene knockout (apoE-KO) mice were exposed to isobaric hypoxic chamber (9%~11% O2, regular chow feed, 23 h/d)for 3 weeks to establish hypoxia-induced pulmonary hypertension. Thirty apoE-KO mice were randomly divided into normoxia group, hypoxia group and hypoxic with apelin (10 nmol/(kg·d), ip) group. The concentrations of high density lipoprotein (HDL), low density lipoprotein (LDL)and total cholesterol in plasma were detected by Elisa method. The mRNA levels of ATP-binding cassette transporter A1(ABCA1), low density lipoprotein receptor (LDLR), scavenger receptor class B1 (SR-B1), and HMG-CoA reductase (HMGCR)in liver were measured by real-time PCR. The protein level of peroxisome proliferators-activated receptor gamma (PPARγ) in lung was measured by Western blot. RESULTS: ①The right ventricular systolic pressure (RVSP) and the weight ratio of right ventricle (RV) to left ventricle plus septum (LV+S) of hypoxia group were significantly higher than those of normoxia group by 87% and 85% (P<0.05), respectively. RVSP and RV/(LV+S) of apelin group were significantly lower than those of hypoxia group by 39% and 33%(P<0.05), respectively. ②The plasma concentration of HDL and HDL/LDL of apelin group were significantly higher than those of hypoxia group by 21% and 20%(P<0.05), respectively. ③The mRNA levels of LDLR, SR-B1 and ABCA1 in liver of apelin group were significantly up-regulated than those of hypoxia group by 241%, 112% and 69% (P<0.05), respectively, while the mRNA level of HMGCR was down-regulated by 45% (P<0.05). ④The protein level of PPARγ in lung of apelin group was significantly up-regulated than that of hypoxia group by 47% (P<0.05). CONCLUSIONS: Apelin attenuates hypoxia-induced pulmonary hypertension of mice through regulation of lipid metabolism.

[Changes of lipid levels in mice with hypoxic pulmonary arterial hypertension].

OBJECTIVE: To observe the changes of lipid levels in mice with pulmonary hypertension induced by hypoxia. METHODS: The animal model of hypoxic pulmonary hypertension was established by exposing the mice to isobaric hypoxic chamberfor 3 weeks (23 h/d, regular chow feed). Twenty male C57BL/6 mice were randomlydivided into normoxia group and hypoxia group (n=10). The concentrations of total cholesterol, low density lipoprotein (LDL) and high density lipoprotein (HDL) in plasma were detected by Elisa method.The mRNA levels of HMG-CoAreductase (HMGCR), low density lipoprotein receptor (LDLR), scavenger receptor class B1 (SR-B1), and sterol regulatory element-binding factor-2 (SREBF2) in liverwere measured by real-time PCR. RESULTS: ① The right ventricular systolic pressure (RVSP) and the weight ratio of right ventricle (RV) to left ventricle plus septum (LV+S) of hypoxia group were significantly higher than those of normoxia group (P<0.05).② The concentrations of HDL and HDL/LDL in plasma were significantly higher in hypoxia group, compared with normoxia group (P<0.05).③The mRNA levels of LDLR and SR-B1in liver were significantly down-regulated in hypoxia group(P<0.05).④RVSP were significantly negative correlated with HDL/LDL, the gene expression of LDLR and SR-B1 (P<0.05). CONCLUSIONS: Abnormal lipid metabolism participates in the pathological proceeding of pulmonary hypertension induced by hypoxia.

[Role of catestatin in 2K1C-induced renal hypertension in rats and the underlying mechanism].

OBJECTIVE: To investigate the roles of catestatin (CST) in 2-kidney-1 clip (2K1C)-induced renal hypertension in rats, and to explore the underlying mechanism. METHODS: Thirty six male SD rats were randomly divided into Sham group (n=15) and Model group(n=21).The model group was performed by 2K1C operation. For 2K1C operation, the left renal arteries were narrowed by cotton thread. The Sham group was treated with the same condition as the 2K1C group except the renal artery was narrowed. Tail-cuff systemic blood pressure of rats was measured before and every weeks after 2K1C operation. Six weeks after 2K1C operation, a carotid artery catheter was inserted to measure blood pressure of rats under anesthesia. Then, the model group was randomly subdivided into 2K1C group (n=15) and 2K1C+CST group (n=6). The rats of 2K1C+CST group were intravenous given CST (80 µg/100 g) and the rats of Sham or 2K1C group were given normal saline. All rats were sacrificed after blood pressure was measured and blood was collected. Then, the left ventricular plus interventricular septum weight (LV+S) was weighted and the ratio of (LV+S)/body weight(BW) was calculated as the index of left ventricular hypertrophy. Norepinephrine (NE) contents in plasma were determined by high performance liquid chromatography(HPLC) and CST contents in plasma by ELISA. The nitrite/nitrate contents in the left ventricular tissue and plasma were measured by nitrate reduction method to represent nitric oxide (NO)contents.Expression levels of CST in the left ventricle, kidney, medulla oblongata and adrenal gland,as well as eNOS and iNOS, were tested by Western blot. RESULTS: ①The 2K1C group had higher tail-artery blood pressure(P<0.01) and were more marked presence of right ventricular hypertrophy than those of sham group (P<0.01). Compared with Sham group, plasma CST content in 2K1C group was decreased by 226% (P<0.01), while plasma NE content in 2K1C group was increased by 246% (P<0.01), expression levels of chromograminA(Chga) in medulla oblongata of 2K1C group were increased by 108%, in leftventricle and kidneywere decreased by 60% and 30%, respectively (P<0.05).the content of NO in left ventricular and plasmawere increased by 46% and 24% respectively. ②The carotid arterial blood pressure of 2K1C group markedly reduced after administration of CST.③Compared with 2K1C group, the content of NO in left ventricul and plasma of 2K1C+CST group were increased by 35% and 19% respectively(P<0.05). The expression of eNOS in left ventricular of 2K1C+CST group were also obviously increased. CONCLUSIONS: The CST expression of 2K1C-induced renal hypertension rats is reduced and the effects of exogenous CST lowering their blood pressure may be related to NO/NOS system.Therefore, we speculate CST could contribute to the pathogenesis and progression of renal hypertension.

Effects of curcumin on TTX-R sodium currents of dorsal root ganglion neurons in type 2 diabetic rats with diabetic neuropathic pain.

Type 2 diabetic mellitus (T2DM) has reached pandemic status and shows no signs of abatement. Diabetic neuropathic pain (DNP) is generally considered to be one of the most common complications of T2DM, which is also recognized as one of the most difficult types of pain to treat. As one kind of peripheral neuropathic pain, DNP manifests typical chronic neuralgia symptoms, including hyperalgesia, allodynia, autotomy, and so on. The injured dorsal root ganglion (DRG) is considered as the first stage of the sensory pathway impairment, whose neurons display increased frequency of action potential generation and increased spontaneous activities. These are mainly due to the changed properties of voltage-gated sodium channels (VGSCs) and the increased sodium currents, especially TTX-R sodium currents. Curcumin, one of the most important phytochemicals from turmeric, has been demonstrated to effectively prevent and/or ameliorate diabetic mellitus and its complications including DNP. The present study demonstrates that the TTX-R sodium currents of small-sized DRG neurons isolated from DNP rats are significantly increased. Such abnormality can be efficaciously ameliorated by curcumin.

LPS Down-Regulates Specificity Protein 1 Activity by Activating NF-κB Pathway in Endotoxemic Mice.

BACKGROUND: Specificity protein (Sp) 1 mediates the transcription of a large number of constitutive genes encoding physiological mediators. NF-κB mediates the expression of hundreds of inducible genes encoding pathological mediators. Crosstalk between Sp1 and NF-κB pathways could be pathophysiologically significant, but has not been studied. This study examined the crosstalk between the two pathways and defined the role of NF-κB signaling in LPS-induced down-regulation of Sp1 activity. METHODS AND MAIN FINDINGS: Challenge of wild type mice with samonelia enteritidis LPS (10 mg/kg, i.p.) down-regulated Sp1 binding activity in lungs in a time-dependent manner, which was concomitantly associated with an increased NF-κB activity. LPS down-regulates Sp1 activity by inducing an LPS inducible Sp1-degrading enzyme (LISPDE) activity, which selectively degrades Sp1 protein, resulting in Sp1 down-regulation. Blockade of NF-κB activation in mice deficient in NF-κB p50 gene (NF-κB-KO) suppressed LISPDE activity, prevented Sp1 protein degradation, and reversed the down-regulation of Sp1 DNA binding activity and eNOS expression (an indicator of Sp1 transactivation activity). Inhibition of LISPDE activity using a selective LISPDE inhibitor mimicked the effects of NF-κB blockade. Pretreatment of LPS-challenged WT mice with a selective LISPDE inhibitor increased nuclear Sp1 protein content, restored Sp1 DNA binding activity and reversed eNOS protein down-regulation in lungs. Enhancing tissue level of Sp1 activity by inhibiting NF-κB-mediated Sp1 down-regulation increased tissue level of IL-10 and decreased tissue level of TNF- αin the lungs. CONCLUSIONS: NF-κB signaling mediates LPS-induced down-regulation of Sp1 activity. Activation of NF-κB pathway suppresses Sp1 activity and Sp1-mediated anti-inflammatory signals. Conversely, Sp1 signaling counter-regulates NF-κB-mediated inflammatory response. Crosstalk between NF-κB and Sp1 pathways regulates the balance between pro- and anti-inflammatory cytokines.

Effects of curcumin on sodium currents of dorsal root ganglion neurons in type 2 diabetic neuropathic pain rats.

Along with the development of economy and society, type 2 diabetic mellitus (T2DM) has become one of the most common diseases at the global level. As one of the complications of T2DM, diabetic neuropathic pain (DNP) stubbornly and chronically affects the health and life of human beings. In the pain field, dorsal root ganglion (DRG) is generally considered as the first stage of the sensory pathway where the hyperexcitability of injured neurons is associated with different kinds of peripheral neuropathic pains. The abnormal electrophysiology is mainly due to the changed properties of voltage-gated sodium channels (VGSCs) and the increased sodium currents (I(Na)). Curcumin is an active ingredient extracted from turmeric and has been demonstrated to ameliorate T2DM and its various complications including DNP effectively. The present study demonstrates that the I(Na) of small-sized DRG neurons are significantly increased with the abnormal electrophysiological characteristics of VGSCs in type 2 diabetic neuropathic pain rats. And these abnormalities can be ameliorated efficaciously by a period of treatment with curcumin.

The Apelin-APJ axis is an endogenous counterinjury mechanism in experimental acute lung injury.

BACKGROUND: Although the mechanisms and pathways mediating ARDS have been studied extensively, less attention has been given to the mechanisms and pathways that counteract injury responses. This study found that the apelin-APJ pathway is an endogenous counterinjury mechanism that protects against ARDS. METHODS: Using a rat model of oleic acid (OA)-induced ARDS, the effects of ARDS on apelin and APJ receptor expressions and on APJ receptor binding capacity were examined. The protective effect of activating the apelin-APJ pathway against OA- or lipopolysaccharide (LPS)-induced ARDS was evaluated. RESULTS: ARDS was coupled to upregulations of the apelin and APJ receptor. Rats with OA-induced ARDS had higher lung tissue levels of apelin proprotein and APJ receptor expressions; elevated plasma, BAL fluid (BALF), and lung tissue levels of apelin-36 and apelin-12/13; and an increased apelin-APJ receptor binding capacity. Upregulation of the apelin-APJ system has important pathophysiologic function. Stimulation of the apelin-APJ signaling using receptor agonist apelin-13 alleviated, whereas inhibition of the apelin-APJ signaling using receptor antagonist [Ala]-apelin-13 exacerbated, OA-induced lung pathologies, extravascular lung water accumulation, capillary-alveolar leakage, and hypoxemia. The APJ receptor agonist inhibited, and the APJ receptor antagonist augmented, OA-induced lung tissue and BALF levels of tumor necrosis factor-α and monocyte chemoattractant protein-1, and plasma and lung tissue levels of malondialdehyde. Postinjury treatment with apelin-13 alleviated lung inflammation and injury and improved oxygenation in OA- and LPS-induced lung injury. CONCLUSIONS: The apelin-APJ signaling pathway is an endogenous anti-injury and organ-protective mechanism that is activated during ARDS to counteract the injury response and to prevent uncontrolled lung injury.

Electroacupuncture and A-317491 depress the transmission of pain on primary afferent mediated by the P2X3 receptor in rats with chronic neuropathic pain states.

P2X is a family of ligand-gated ion channels that act through adenosine ATP. The P2X3 receptor plays a key role in the transmission of neuropathic pain at peripheral and spinal sites. Electroacupuncture (EA) has been used to treat neuropathic pain effectively. To determine the role of EA in neuropathic pain mediated through the P2X3 receptor in dorsal root ganglion neurons and the spinal cord, a chronic constriction injury (CCI) model was used. Sprague-Dawley rats were divided into four groups: sham CCI, CCI, CCI plus contralateral EA, and CCI plus ipsilateral EA. The mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were recorded. Furthermore, the expression of the P2X3 receptor was evaluated through Western blotting and immunofluorescence. The effects of EA and A-317491 were investigated through the whole-cell patch-clamp method and intrathecal administration. Our results show that the MWT and TWL of EA groups were higher than those in the CCI group, whereas the expression of the P2X3 receptor was lower than that in the CCI group. However, no significant difference was detected between the two EA groups. EA depressed the currents created by ATP and the upregulation of the P2X3 receptor in CCI rats. Additionally, EA was more potent in reducing mechanical allodynia and thermal hyperalgesia when combined with A-317491 through intrathecal administration. These results show that both contralateral and ipsilateral EA might inhibit the primary afferent transmission of neuropathic pain induced through the P2X3 receptor. In addition, EA and A-317491 might have an additive effect in inhibiting the transmission of pain mediated by the P2X3 receptor.

[Effect of autophagy inhibitor chloroquine on the proliferation of PASMCs induced by hypoxia].

OBJECTIVE: To investigate the role of autophagy inhibitor chloroquine (CQ) in the proliferation of pulmonary arterial smooth muscle cells (PASMCs) in hypoxia conditions. METHODS: The following groups in this study were set up: control group, hypoxia group, 50 micromol/L CQ + hypoxia group, 50 micromol/L CQ group. The viability of PASMCs in every group was detected by MTT assay. Autophagic vacuoles in the cells were observed by MDC staining. Protein expression of microtubule associated protein light chain 3 (LC3) was measured by Western blot. Migration of PASMCs was detected by wound healing assay. RESULTS: Compared with control group, no effect on the viability of PASMCs was observed treated by CQ alone. In 1% hypoxia group, cell viability increased significantly compared with that in control group. The number of autophagic vacuoles and the rate of cell migration and also protein expression of LC3-II were also markedly increased. Compared with hypoxia group, addition of CQ increased the number of autophagic vacuoles and the levels of LC3-II protein, but decreased the proliferation and migration of PASMCs. CONCLUSION: Hypoxia could activates autophagy and contributes to proliferation and migration of PASMCs, and autophagy inhibitor CQ could decrease the effect of hypoxia on PASMCs through inhibiting autophagy process.

Intermedin modulates hypoxic pulmonary vascular remodeling by inhibiting pulmonary artery smooth muscle cell proliferation.

BACKGROUND: Hypoxic pulmonary arterial hypertension (PAH) is a disabling disease with limited treatment options. Hypoxic pulmonary vascular remodeling is a major cause of hypoxic PAH. Pharmacological agents that can inhibit the remodeling process may have great therapeutic value. OBJECTIVE: To examine the effect of intermedin (IMD), a new calcitonin gene-related peptide family of peptide, on hypoxic pulmonary vascular remodeling. METHODS: Rats were exposed to normoxia or hypoxia (∼10% O(2)), or exposed to hypoxia and treated with IMD, administered by an implanted mini-osmotic pump (6.5 µg/rat/day), for 4 weeks. The effects of IMD infusion on the development of hypoxic PAH and right ventricle (RV) hypertrophy, on pulmonary vascular remodeling, on pulmonary artery smooth muscle cell (PASMC) proliferation and apoptosis, and on the activations of l-arginine nitric oxide (NO) pathway and endoplasmic reticulum stress apoptotic pathway were examined. RESULTS: Rats exposed to hypoxia developed PAH and RV hypertrophy. IMD treatment alleviated PAH and prevented RV hypertrophy. IMD inhibited hypoxic pulmonary vascular remodeling as indicated by reduced wall thickness and increased lumen diameter of pulmonary arterioles, and decreased muscularization of distal pulmonary vasculature in hypoxia-exposed rats. IMD treatment inhibited PASMC proliferation and promoted PASMC apoptosis. IMD treatment increased tissue level of constitutive NO synthase activity and tissue NO content in lungs, and enhanced l-arginine uptake into pulmonary vascular tissues. IMD treatment increased cellular levels of glucose-regulated protein (GRP) 78 and GRP94, two major markers of endoplasmic reticulum (ER) stress, and increased caspase-12 expression, the ER stress-specific caspase, in lungs and cultured PASMCs. CONCLUSIONS: These results demonstrate that IMD treatment attenuates hypoxic pulmonary vascular remodeling, and thereby hypoxic PAH mainly by inhibiting PASMC proliferation. Promotion of PASMC apoptosis may also contribute to the inhibitory effect of IMD. Activations l-arginine-NO pathway and of ER stress-specific apoptosis pathway could be the mechanisms mediating the anti-proliferative and pro-apoptotic effects of IMD.

[Changes of apelin and its receptor in lung tissue of rats with pulmonary hypertension induced by monocrotaline].

OBJECTIVE: To observe the change of apelin and its receptor (APJ) in the lung tissue of rats with pulmonary hypertension induced by monocrotaline and to explore its significance. METHODS: Twenty-five male SD rats were randomly divided into control group (n = 10) and monocrotaline group (n = 15). On the twenty-first day after the rats were intraperitoneally injected 60 mg/kg monocrotaline for monocrotaline group or equal volume vehicle for control group, the mean pulmonary artery pressure was measured by right heart catheterization. Histopathological study of lung tissue was done with hematoxylin-eosin (HE) and Masson's trichrome staining. The concentration of apelin in the plasma was measured by radioimmunoassay. The expressions of apelin/APJ proteins and genes in lung tissue were measured respectively by Western blot and reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The mean pulmonary arterial pressure, right ventricular hypertrophy, pulmonary vascular remodeling index, content of apelin protein in lung tissue of monocrotaline group were higher than those in control group. APJ protein and gene expression in monocrotaline group were significantly lower than those in control group (P < 0.01, P < 0.05), but apelin gene expression in the lung tissue between the two groups had no significant difference. CONCLUSION: Endogenous apelin/APJ dysfunction may play an important role in the development of pulmonary hypertension induced by monocrotaline.

[Migratory properties of vascular smooth muscle cells on extracellular matrix: a study on inverted coverslip migration assay].

Migration of vascular smooth muscle cells (VSMCs) is involved in vascular development and various vascular diseases; however, the molecular mechanisms of VSMC migration remain unclear. In this study, we established an inverted coverslip migration assay to study the migratory properties of cultured VSMCs on extracellular matrix. Pulmonary arterial smooth muscle cells (PASMCs) from rats were cultured and identified by immunocytochemistry. Each coverslip with a confluent monolayer of PASMCs was inverted to a larger coverslip which was coated with phosphate buffered saline (PBS, as a control), poly-D-lysine hydrobromide (PDL), laminin or Matrigel. After 24 h of migration over the larger coverslip, PASMCs were fixed, and reliably quantified. The roles and mechanisms of extracellular matrix in PASMC migration were further studied by wound-healing assay and immunocytochemistry. The results showed that: (1) The purity of the cultured PASMCs was (97 ± 3)%. (2) The number of PASMCs on laminin or Matrigel migrating out from the inverted coverslip was significantly increased compared with that on PBS or PDL, and the migratory distance of PASMCs on laminin or Matrigel was significantly farther than that on PBS or PDL. (3) The motility of PASMCs on laminin or Matrigel was significantly higher than that on PBS at 8 h, 12 h and 24 h after wounding, respectively. (4) F-actin staining showed that F-actin was congregated along the brim of the migrating cells from the inverted coverslip, and vinculin (a cell marker of focal adhesion) staining showed that the distribution of vinculin in PASMCs plated on laminin or Matrigel was significantly lower than that on PBS or PDL. These results suggest that the inverted coverslip migration assay is suitable to study VSMC migration, and laminin and Matrigel substrates may promote VSMC migration through inhibiting the formation of focal adhesion and regulating the cytoskeletal proteins.