Macrophage exosomes transfer angiotensin II type 1 receptor to lung fibroblasts mediating bleomycin-induced pulmonary fibrosis.

BACKGROUND: Macrophages are involved in the pathogenesis of idiopathic pulmonary fibrosis, partially by activating lung fibroblasts. However, how macrophages communicate with lung fibroblasts is largely unexplored. Exosomes can mediate intercellular communication, whereas its role in lung fibrogenesis is unclear. Here we aim to investigate whether exosomes can mediate the crosstalk between macrophages and lung fibroblasts and subsequently induce fibrosis. METHODS: In vivo, bleomycin (BLM)-induced lung fibrosis model was established and macrophages infiltration was examined. The effects of GW4869, an exosomes inhibitor, on lung fibrosis were assessed. Moreover, macrophage exosomes were injected into mice to observe its pro-fibrotic effects. In vitro, exosomes derived from angiotensin II (Ang II)-stimulated macrophages were collected. Then, lung fibroblasts were treated with the exosomes. Twenty-four hours later, protein levels of α-collagen I, angiotensin II type 1 receptor (AT1R), transforming growth factor-ß (TGF-ß), and phospho-Smad2/3 (p-Smad2/3) in lung fibroblasts were examined. The Student's t test or analysis of variance were used for statistical analysis. RESULTS: In vivo, BLM-treated mice showed enhanced infiltration of macrophages, increased fibrotic alterations, and higher levels of Ang II and AT1R. GW4869 attenuated BLM-induced pulmonary fibrosis. Mice with exosomes injection showed fibrotic features with higher levels of Ang II and AT1R, which was reversed by irbesartan. In vitro, we found that macrophages secreted a great number of exosomes. The exosomes were taken by fibroblasts and resulted in higher levels of AT1R (0.22 ±â€Š0.02 vs. 0.07 ±â€Š0.02, t = 8.66, P = 0.001), TGF-ß (0.54 ±â€Š0.05 vs. 0.09 ±â€Š0.06, t = 10.00, P < 0.001), p-Smad2/3 (0.58 ±â€Š0.06 vs. 0.07 ±â€Š0.03, t = 12.86, P < 0.001) and α-collagen I (0.27 ±â€Š0.02 vs. 0.16 ±â€Š0.01, t = 7.01, P = 0.002), and increased Ang II secretion (62.27 ±â€Š7.32 vs. 9.56 ±â€Š1.68, t = 12.16, P < 0.001). Interestingly, Ang II increased the number of macrophage exosomes, and the protein levels of Alix (1.45 ±â€Š0.15 vs. 1.00 ±â€Š0.10, t = 4.32, P = 0.012), AT1R (4.05 ±â€Š0.64 vs. 1.00 ±â€Š0.09, t = 8.17, P = 0.001), and glyceraldehyde-3-phosphate dehydrogenase (2.13 ±â€Š0.36 vs. 1.00 ±â€Š0.10, t = 5.28, P = 0.006) were increased in exosomes secreted by the same number of macrophages, indicating a positive loop between Ang II and exosomes production. CONCLUSIONS: Exosomes mediate intercellular communication between macrophages and fibroblasts plays an important role in BLM-induced pulmonary fibrosis.

[Carbon Monoxide and Pain Regulation: A Review].

Carbon monoxide (CO) is an endogenous gasotransmitter produced by the degradation of heme in the presence of heme oxygenase (HO) in mammals. It has been demonstrated that CO participates in a variety of physiological activities and pathological processes, and is closely related to cell protection and homeostasis maintenance in organ tissues. It has been shown by a growing number of studies that CO may play a regulatory and interventional role in the process of the occurrence and development of pain through a variety of mechanisms of action. However, its mechanism of action is still not fully understood and the uncontrollable factors concerning CO administration also placed considerable limitation to its application. This paper reviews the potential targets and pathways of CO in pain regulation and discusses the challenges and opportunities in the clinical application of CO in order to provide suggestions for further exploration and development of CO analgesics.

The Pull-Through Technique for Recanalization of Transjugular Intrahepatic Portosystemic Shunt Dysfunction.

PURPOSE: To evaluate the technical efficacy and safety of the pull-through technique in recanalization of transjugular intrahepatic portosystemic shunt (TIPS) when standard transjugular approach is inaccessible. MATERIALS AND METHODS: A retrospective review of patients underwent TIPS revision via the pull-through technique was performed. Transhepatic directly punctured stent was conducted if the portal vein could not be accessed via standard transjugular approach. Technical success was defined by recanalization of shunt. Clinical success was defined as bleeding interruption and ascites regression without pharmacological support. All patients were followed up by clinical evaluation and Doppler ultrasound. RESULTS: Between January 2010 and December 2016, a total of 63 patients underwent TIPS revision, and 14 of them could not be accessed via standard transjugular approaches owing to stenosis or occlusion of the hepatic vein. The pull-through technique was successful in 13 patients, and one patient underwent parallel TIPS. No procedure-related complication was observed. One patient died of liver failure one week after the procedure. During the follow-up, three patients developed hepatic encephalopathy, and one patient developed TIPS dysfunction again and experienced variceal bleeding. The primary patency rate after TIPS revision was 92% (11/12) at 12 months. CONCLUSION: The pull-through technique was effective and safe for recanalization of TIPS inaccessible via standard transjugular approach.

Glycerin Monostearate Aggravates Male Reproductive Toxicity Caused by Di(2-ethylhexyl) Phthalate in Rats.

Human beings are increasingly exposed to phthalates, which are a group of chemicals used to make plastics more flexible and harder to break, and simultaneously ingesting abundant food emulsifiers via daily diet. The purpose of this study was to investigate the effect of the food emulsifier glycerin monostearate (GMS) on male reproductive toxicity caused by di(2-ethylhexyl) phthalate (DEHP, one of the phthalates) and explore the underlying mechanism. Thirty male Sprague-Dawley rats were randomly divided into control group, DEHP group and DEHP+GMS group. Rats in the DEHP group and DEHP+GMS group were orally administered with 200 mg/kg/d DEHP with or without 20 mg/kg/d GMS. After 30 days of continuous intervention, it was found that the serum testosterone level was significantly lowered in DEHP group and DEHP+GMS group than that in control group (P<0.01). The serum testosterone level and the relative testis weight were significantly decreased in the DEHP+GMS group as compared with those in the DEHP group and control group (P<0.05). More spermatids were observed to be shed off in DEHP+GMS group than in DEHP group. The expression levels of cell cycle checkpoint kinase 1 (Chk1), cell division cycle gene 2 (Cdc2), and cyclin-dependent kinase 2 (CDK2) were down-regulated in DEHP group, and this tendency was more significant in DEHP+GMS group (P<0.05 or P<0.01). There was no significant difference in the P-glycoprotein (P-gp) expression between DEHP group and control group. However, P-gp was markedly down-regulated in DEHP+GMS group (P<0.01). The results indicated that the food emulsifier GMS aggravated the toxicity of DEHP on male reproduction by inhibiting the cell cycle of testicular cells and the expression of P-gp in testis tissues.

MicroRNA-21 Mediates Angiotensin II-Induced Liver Fibrosis by Activating NLRP3 Inflammasome/IL-1ß Axis via Targeting Smad7 and Spry1.

AIMS: Angiotensin II (AngII), a vasoconstrictive peptide of the renin-angiotensin system (RAS), promotes hepatic fibrogenesis and induces microRNA-21(mir-21) expression. Angiotensin-(1-7) [Ang-(1-7)] is a peptide of the RAS, which attenuates liver fibrosis. Recently, it was reported that the NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome participated in liver fibrosis. However, it remains unclear how mir-21 mediates AngII-induced NLRP3 inflammasome activation. We investigate the role of AngII-induced mir-21 in the regulation of NLRP3 inflammasome/IL-1ß axis in liver fibrosis. RESULTS: In vivo, circulating mir-21 was upregulated in patients with liver fibrosis and was positively correlated with liver fibrosis and oxidation. Treatment with Ang-(1-7) inhibited mir-21, NLRP3 inflammasome, and liver fibrosis after bile duct ligation (BDL) or AngII infusion. Inhibition of mir-21 suppressed the Smad7/Smad2/3/NOX4, Spry1/ERK/NF-κB pathway, NLRP3 inflammasome, and liver fibrosis induced by AngII infusion. In vitro, AngII upregulated mir-21 expression via targeting Smad7 and Spry1 in primary hepatic stellate cells (HSCs). In contrast, Ang-(1-7) suppressed mir-21 expression and oxidation induced by AngII. Overexpression of mir-21 promoted oxidation, and collagen production enhanced the effect of AngII on NLRP3 inflammasome activation via the Spry1/ERK/NF-κB, Smad7/Smad2/3/NOX4 pathways. However, downregulation of mir-21 exerted the opposite effects. Innovation and Conclusions: Mir-21 mediates AngII-activated NLRP3 inflammasome and resultant HSC activation via targeting Spry1 and Smad7. Ang-(1-7) protected against BDL or AngII infusion-induced hepatic fibrosis and inhibited mir-21 expression. Antioxid. Redox Signal. 27, 1-20.

Angiotensin(1-7) attenuated Angiotensin II-induced hepatocyte EMT by inhibiting NOX-derived H2O2-activated NLRP3 inflammasome/IL-1ß/Smad circuit.

Epithelial-mesenchymal transition (EMT) is correlated with NAPDH oxidase (NOX)-derived reactive oxygen species (ROS). The ROS-induced NOD-like receptor pyrin domain containing-3 (NLRP3) inflammasome is a novel mechanism of EMT. Angiotensin II (AngII) induces EMT by regulating intracellular ROS. Nevertheless, it has not been reported whether AngII could induce hepatocyte EMT. Angiotensin-(1-7) [Ang-(1-7)] can inhibit the effects of AngII via a counter-regulatory mechanism. However, whether Ang-(1-7) attenuated the effects of AngII on hepatocyte EMT remains unclear. The aim of this study was to determine whether Ang-(1-7) attenuated AngII-induced hepatocyte EMT by inhibiting the NOX-derived ROS-mediated NLRP3 inflammasome/IL-1ß/Smad circuit. In vivo, two animal models were established. In the first model, rats were infused AngII. In the second model, Ang-(1-7) was constantly infused into double bile duct ligated (BDL) rats. In vitro, hepatocytes were pretreated with antioxidant, NLRP3 siRNA, NOX4 siRNA, or Ang-(1-7) before exposure to AngII. In vitro, AngII induced hepatocyte EMT, which was inhibited by N-acetylcysteine (NAC), diphenylene iodonium (DPI), and NOX4 siRNA. NLRP3 inflammasome, which was activated by hydrogen peroxide (H2O2), mediated AngII-induced hepatocyte EMT. Ang-(1-7) suppressed AngII-induced EMT by inhibiting the NOX-derived H2O2-activated NLRP3 inflammasome/IL-1ß/Smad circuit. In vivo, infusion of AngII induced activation of H2O2-correlated NLRP3 inflammasome in rat livers and accumulation of α-collagen I (Col1A1) in hepatocytes. Infusion of Ang-(1-7) alleviated BDL-induced liver fibrosis and inhibited the expression of Col1A1 and the activation of NLRP3 inflammasome in hepatocytes. Ang-(1-7) attenuated AngII-induced hepatocyte EMT by inhibiting the NOX-derived H2O2-activated NLRP3 inflammasome/IL-1ß/Smad circuit.

[NLRP3 inflammasome mediates angiotension II-induced expression of inflammatory factor interleukin-1ß in human umbilical vein endothelial cells].

OBJECTIVE: To investigate the effect of angiotension II (AngII) on the activation of NLRP3 inflammasome and the expression of interleukin-1ß (IL-1ß) in human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs cultured in vitro were treated with different concentrations of AngII for varying lengths of time to determine the optimal concentration and time for AngII exposure. To test the impact of different agents on the effect of AngII exposure, HUVECs were pretreated with AngII receptor blocker losartan, NAD(P)H inhibitor DPI and H(2)O(2) scavenger CAT, caspase 1 inhibitor YVAD, or NLRP3 siRNA for silencing NLRP3, and the protein levels of NOX4, NLRP3, caspase-1 and IL-1ß in HUVECs were analyzed by Western blotting. RESULTS: AngII treatment at the optimal concentration (10(-9) mol/L) for 12 h significantly increased the protein levels of NOX4, NLRP3, caspase1 and IL-1ß in HUVECs. Pretreatment with losartan, DPI, CAT, YVAD, or NLRP3 siRNA all attenuated the effects of AngII on the cells. CONCLUSION: AngII can induce vascular inflammation by promoting the production of reactive oxygen species and activating NLRP3 inflammasome to increase the protein expression of IL-1ß in HUVECs.