Pirfenidone alleviates vascular intima injury caused by hyperhomocysteinemia.

OBJECTIVES: Hyperhomocysteinemia (HHcy) can induce vascular inflammatory and oxidative damage and accelerate intimal hyperplasia. This study investigated the protective effect of pirfenidone (PFD) on the recovery process of injured endothelial arteries during HHcy. MATERIALS AND METHODS: Thirty rabbits were randomly separated into three groups: A control group (n=10, standard rabbit chow), a model group (n=10, control diet plus 30 g methionine/kg food), and a PFD group (n=10, model diet plus oral administration of 90 mg/day of PFD). After 14 weeks of arterial injury, histopathological changes were determined. Plasma homocysteine (Hcy) concentrations, lipid profiles and oxidant and antioxidant status were evaluated. Macrophage infiltration was assessed using immunohistochemical staining. RESULTS: PFD supplementation decreased macrophage infiltration of iliac artery significantly without changes in blood lipids and Hcy concentrations. Compared with the model group, PFD restored superoxide dismutase and glutathione peroxidase activities and reduced malondialdehyde and reactive oxygen species levels. A high-methionine diet significantly increased neointimal area and the ratio between neointimal and media area. Systemic administration of PFD inhibited neointimal formation. CONCLUSIONS: PFD can partly alleviate intimal hyperplasia by inhibiting inflammatory and oxidative stress response induced by HHcy during endothelial injury. It may be a potential therapeutic agent for the prevention and treatment of endothelial injury-associated diseases such as atherosclerosis.

Intravenous transplantation of mesenchymal stromal cells has therapeutic effects in a sepsis mouse model through inhibition of septic natural killer cells.

Transplantation of mesenchymal stromal cells is a promising strategy for treating sepsis. Natural killer cells are important in the development of sepsis, and their functions can be inhibited by mesenchymal stromal cells, we asked whether mesenchymal stromal cells exert their therapeutic effects through inhibiting the functions of natural killer cells in a septic mouse model generated with cecal ligation puncture method. Using co-cultures of cells, small interfering RNA, enzyme-linked immnuosorbent assays, fluorescence assays, western blotting, and pathological examination, we investigated the levels of inflammatory cytokines, proliferation of natural killer cells, inflammatory infiltration of important organs in mice, and activity of the Janus kinase/signal transducer and activator of transcription signaling pathway and found that mesenchymal stromal cells inhibited the function and proliferation of septic natural killer cells, increased interleukin-10 levels and increased the expression of components, such as Janus kinase 1, Janus kinase 2, and signal transducer and activator of transcription 3 in the Janus kinase/signal transducer and activator of transcription pathway both in vitro and in vivo. We conclude that mesenchymal stromal cells have their therapeutic effect in the septic mouse model through inhibiting the function and proliferation of septic natural killer cells. This biological process may involve interleukin-10 and suppressor of cytokine signaling 3 as well as other pathway components in the Janus kinase/signal transducer and activator of transcription pathway. Transplantation of mesenchymal stromal cells is an effective strategy to treat sepsis.

Urinary Trypsin Inhibitor Reduced Inflammation Response Induced by Hyperlipidemia.

INTRODUCTION AND OBJECTIVES: Atherosclerosis is recognized as a chronic inflammatory disease. The aim of this study was to examine the role of urinary trypsin inhibitor (UTI) in inflammation response induced by hyperlipidemia in rabbits. METHODS: Thirty rabbits after injury of the right iliac artery endothelium were randomly divided into 3 groups: control group, model group, and UTI group. Iliac arteries were isolated and histology was performed on arterial regions that were injured by balloon after 8 weeks. Neointimal thickness (NT) and neointimal to media radio (N/M) were measured. Blood lipids, interleukin 6, and tumor necrosis factor-α were evaluated. Macrophages were evaluated by immunohistochemical analysis. MicroRNA-181b (miR-181b) was measured by reverse transcriptase-polymerase chain reaction. RESULTS: Urinary trypsin inhibitor therapy decreased serum inflammatory factor levels without significant changes in blood lipids. Compared with model group, UTI reduced macrophage infiltration of iliac artery (13.91 ± 2.03% vs 24.21 ± 8.94%, P < .01). Hyperlipidemia reduced the expression of miR-181b and increased NT and N/M ratio. Systemic administration of UTI rescued miR-181b expression and inhibited neointimal formation. CONCLUSIONS: Urinary trypsin inhibitor could reduce neointimal hyperplasia by inhibiting inflammatory response induced by hyperlipidemia and may become a potential antiatherosclerosis supplement.

Colchicine reduces restenosis after balloon angioplasty treatment for in-stent restenosis.

BACKGROUND AND AIMS: Treatment of coronary in-stent restenosis (ISR) is hampered by a high incidence of recurrent ISR. Colchicine is an old drug with known anti-inflammatory and antiproliferative actions. We evaluated the strategy of colchicine combined with conventional balloon angioplasty for the treatment of ISR. METHODS AND RESULTS: Sixty coronary arteries of 60 mini-pigs underwent oversized bare-metal stent implantation to induce ISR. After 28 days, vessels with ISR (≥50% diameter stenosis) were randomly divided into three groups: control (conventional balloon angioplasty combined with placebo), colchicine (conventional balloon angioplasty combined with colchicine) and drug-eluting balloon (DEB). Restenosis and neointima formation were elevated with angiography and histological and morphometric analysis at 28 days after different interventions. Late lumen loss and percent area stenosis at follow-up were lower in colchicine group compared to control group but were similar to those of DEB group. There was no significant difference in proliferating cell nuclear antigen-positive vascular smooth muscle cells and inflammatory score between the colchicine group and the DEB group. CONCLUSIONS: The efficacy of colchicine combined with conventional balloon angioplasty for treatment of ISR was comparable to that of DEB. Treatment of ISR might not require a second stent implantation, and colchicine combined with conventional balloon angioplasty seemed to be another consideration.

Cutting balloon combined with paclitaxel-eluting balloon for treatment of in-stent restenosis.

BACKGROUND: The optimal therapy for in-stent restenosis (ISR) is controversial. We evaluated three different strategies for the treatment of in-stent restenosis: cutting balloon angioplasty (CBA), paclitaxel-eluting balloon angioplasty (PEBA) and cutting balloon followed by paclitaxel-eluting balloon angioplasty (CB+PEBA). METHODS: Forty-five coronary arteries in 45 mini-pigs underwent oversized bare-metal stent (stent-to-artery ratio, 1.2:1) implantation to induce in-stent restenosis. After 28 days, vessels with in-stent restenosis (≥50% diameter stenosis) were randomly divided into three groups: CBA, PEBA and CB+PEBA. In vivo angiography was performed before intervention, immediately after intervention and at 28-day follow-up. Stented arteries were harvested for pathological analyses. The proliferation and apoptosis of vascular smooth muscle cells were evaluated by immunohistochemical staining and the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay, respectively. RESULTS: Acute lumen gain was not different between the three groups. Late lumen loss and neointimal area at follow-up were lower for CB+PEBA compared with CBA but similar for CB+PEBA compared with PEBA. There were no significant differences in proliferating cell nuclear antigen-positive vascular smooth muscle cells and TUNEL-positive vascular smooth muscle cells between the CB+PEBA and PEBA groups. CONCLUSIONS: PEBA with or without cutting balloon was superior to CBA alone for in-stent restenosis. The underlying mechanism was probably related to inhibition of smooth muscle cell proliferation and increased apoptosis. In this porcine coronary artery restenosis model, PEBA with or without cutting balloon was superior.

Urinary trypsin inhibitor reduced neointimal hyperplasia induced by systemic inflammation after balloon injury in rabbits.

OBJECTIVES: The aims of this study were to evaluate the effect of urinary trypsin inhibitor (UTI) on the regulation of inflammatory cytokines induced by lipopolysaccharide (LPS) and the reduction of neointimal formation in rabbits. METHODS AND RESULTS: Rabbits subjected to iliac artery balloon injury were randomly divided into three groups: control group (balloon injury), LPS group (LPS + balloon injury) and UTI group (UTI + LPS + balloon injury). Systemic markers of inflammation (serum IL-1ß and TNF-α levels measured by ELISA) were increased after LPS administration. Arterial nuclear factor-κB (NF-κB/p65) at 28 days after injury was 31.50 ± 7.08 % of total cells in controls and 73.50 ± 6.90 % in LPS group (P < 0.05). Morphometric analysis of the injured arteries at 28 days revealed significantly increased luminal stenosis (45.81 ± 5.31 vs 27.93 ± 2.85 %, P < 0.05) and neointima-to-media ratio (1.40 ± 0.15 vs 0.68 ± 0.12, P < 0.05) in LPS-treated animals compared with controls. This effect was reduced by UTI administration. Serum IL-1ß and TNF-α levels and NF-κB/p65 expression were significantly increased in correlation with the severity of intimal hyperplasia and inhibited by UTI. CONCLUSIONS: Systemic inflammatory response concurrently with arterial vascular injury facilitated neointimal formation. UTI reduced neointimal hyperplasia by regulating inflammatory response and could be considered as a potential anti-restenosis supplement.

A novel polymer-free paclitaxel-eluting stent with a nanoporous surface for rapid endothelialization and inhibition of intimal hyperplasia: Comparison with a polymer-based sirolimus-eluting stent and bare metal stent in a porcine model.

Hypersensitivity and inflammatory responses to polymers may be responsible for late stent thrombosis after implantation of a drug-eluting stent (DES). Polymer-free DES may reduce the prevalence of these adverse reactions in vessels. We evaluated a polymer-free paclitaxel-eluting-stent with a nanoporous surface (nano-PES) for endothelialization and inhibition of neointimal hyperplasia by optical coherence tomography (OCT) and pathology in a porcine model. Nano-PES with high-dose (HD) and low-dose (LD) paclitaxel (1.0 µg/mm(2) and 0.4 µg/mm(2), respectively) was compared with a sirolimus-eluting stent (SES) and bare-metal stent (BMS) in a porcine model. Fifty-three stents (14 HD, 14 LD, 14 SES, 11 BMS) were implanted in 18 minipigs. At 14 days, nano-PES with HD and LD showed more complete endothelialization compared with SES. BMS had 100% endothelial coverage. At 28 days, a significant reduction in neointimal hyperplasia was detected by OCT in the nano-PES HD group compared with BMS. No benefit in prevention of the neointimal hyperplasia was observed in the nano-PES LD group. Nano-PES stents showed decreased deposition of fibrin and inflammation compared with SES. Pharmacokinetic studies revealed that nano-PES could effectively deliver the drug to the local coronary artery and it released the drug more rapidly than SES. Such a release profile was favorable for rapid endothelialization of nano-PES. The present study showed the nano-PES to be a new drug-delivery technology; that it used a nanoporous stent surface; that it offered desirable drug-elution properties without the use of polymers; that it may translate into an improved safety profile for next-generation DES.