Carbon nanotube recognition by human Siglec-14 provokes inflammation.

For the design and development of innovative carbon nanotube (CNT)-based tools and applications, an understanding of the molecular interactions between CNTs and biological systems is essential. In this study, a three-dimensional protein-structure-based in silico screen identified the paired immune receptors, sialic acid immunoglobulin-like binding lectin-5 (Siglec-5) and Siglec-14, as CNT-recognizing receptors. Molecular dynamics simulations showed the spatiotemporally stable association of aromatic residues on the extracellular loop of Siglec-5 with CNTs. Siglec-14 mediated spleen tyrosine kinase (Syk)-dependent phagocytosis of multiwalled CNTs and the subsequent secretion of interleukin-1ß from human monocytes. Ectopic in vivo expression of human Siglec-14 on mouse alveolar macrophages resulted in enhanced recognition of multiwalled CNTs and exacerbated pulmonary inflammation. Furthermore, fostamatinib, a Syk inhibitor, blocked Siglec-14-mediated proinflammatory responses. These results indicate that Siglec-14 is a human activating receptor recognizing CNTs and that blockade of Siglec-14 and the Syk pathway may overcome CNT-induced inflammation.

Tim4, a macrophage receptor for apoptotic cells, binds polystyrene microplastics via aromatic-aromatic interactions.

Understanding the interface between microplastics and biological systems will provide new insights into the impacts of microplastics on living organisms. When microplastics enter the body, they are engulfed preferentially by phagocytes such as macrophages. However, it is not fully understood how phagocytes recognize microplastics and how microplastics impact phagocyte functions. In this study, we demonstrate that T cell immunoglobulin mucin 4 (Tim4), a macrophage receptor for phosphatidylserine (PtdSer) on apoptotic cells, binds polystyrene (PS) microparticles as well as multi-walled carbon nanotubes (MWCNTs) through the extracellular aromatic cluster, revealing a novel interface between microplastics and biological systems via aromatic-aromatic interactions. Genetic deletion of Tim4 demonstrated that Tim4 is involved in macrophage engulfment of PS microplastics as well as of MWCNTs. While Tim4-mediated engulfment of MWCNTs causes NLRP3-dependent IL-1ß secretion, that of PS microparticles does not. PS microparticles neither induce TNF-α, reactive oxygen species, nor nitric oxide production. These data indicate that PS microparticles are not inflammatory. The PtdSer-binding site of Tim4 contains an aromatic cluster that binds PS, and Tim4-mediated macrophage engulfment of apoptotic cells, a process called efferocytosis, was competitively blocked by PS microparticles. These data suggest that PS microplastics do not directly cause acute inflammation but perturb efferocytosis, raising concerns that chronic exposure to large amounts of PS microplastics may cause chronic inflammation leading to autoimmune diseases.

Characteristics, Antithrombotic Patterns, and Prognostic Outcomes in Claudication and Critical Limb-Threatening Ischemia Undergoing Endovascular Therapy.

PURPOSE: The underlying difference between intermittent claudication (IC) and critical limb-threatening ischemia (CLTI) still remains unclear. This prospective multicenter observational study aimed to clarify differences in clinical features and prognostic outcomes between IC and CLTI, and prognostic factors in patients undergoing endovascular therapy (EVT). MATERIALS AND METHODS: A total of 692 patients with 808 limbs were enrolled from 20 institutions in Japan. The primary measurements were the 3-year rates of major adverse cardiovascular event (MACE) and reintervention. RESULTS: Among patients, 79.0% had IC and 21.0% had CLTI. Patients with CLTI were more frequently women and more likely to have impaired functional status, undernutrition, comorbidities, hypercoagulation, hyperinflammation, distal artery disease, short single antiplatelet and long anticoagulation therapies, and late cilostazol than patients with IC. Aortoiliac and femoropopliteal diseases were dominant in patients with IC and infrapopliteal disease was dominant in patients with CLTI. Patients with CLTI underwent less frequently aortoiliac intervention and more frequently infrapopliteal intervention than patients with IC. Longitudinal change of ankle-brachial index (ABI) exhibited different patterns between IC and CLTI (pinteraction=0.002), but ABI improved after EVT both in IC and in CLTI (p<0.001), which was sustained over time. Dorsal and plantar skin perfusion pressure in CLTI showed a similar improvement pattern (pinteraction=0.181). Distribution of Rutherford category improved both in IC and in CLTI (each p<0.001). Three-year MACE rates were 20.4% and 42.3% and 3-year reintervention rates were 22.1% and 46.8% for patients with IC and CLTI, respectively (log-rank p<0.001). Elevated D-dimer (p=0.001), age (p=0.043), impaired functional status (p=0.018), and end-stage renal disease (p=0.019) were independently associated with MACE. After considering competing risks of death and major amputation for reintervention, elevated erythrocyte sedimentation rate (p=0.003) and infrainguinal intervention (p=0.002) were independently associated with reintervention. Patients with CLTI merely showed borderline significance for MACE (adjusted hazard ratio 1.700, 95% confidence interval 0.950-3.042, p=0.074) and reintervention (adjusted hazard ratio 1.976, 95% confidence interval 0.999-3.909, p=0.05). CONCLUSIONS: The CLTI is characterized not only by more systemic comorbidities and distal disease but also by more inflammatory coagulation disorder compared with IC. Also, CLTI has approximately twice MACE and reintervention rates than IC, and the underlying inflammatory coagulation disorder per se is associated with these outcomes. CLINICAL IMPACT: The underlying difference between intermittent claudication (IC) and critical limb-threatening ischemia (CLTI) still remains unclear. This prospective multicenter observational study, JPASSION study found that CLTI was characterized not only by more systemic comorbidities and distal disease but also by more inflammatory coagulation disorder compared to IC. Also, CLTI had approximately twice major adverse cardiovascular event (MACE) and reintervention rates than IC. Intriguingly, the underlying inflammatory coagulation disorder per se was independently associated with MACE and reintervention. Further studies to clarify the role of anticoagulation and anti-inflammatory therapies will contribute to the development of post-interventional therapeutics in the context of peripheral artery disease.

Clinical outcome of the patients with femoropopliteal artery disease after endovascular therapy: focused on drug-coated-balloon-related distal embolism detected by laser doppler flowmetry.

Several trials have shown that paclitaxel drug-coated balloons (DCBs) significantly reduce restenosis rates. However, some reports have shown distal embolisms occurring after DCBs. No study has analyzed the clinical outcomes of patients with DCB-induced distal embolism. This study aimed to investigate the clinical outcomes of DCB-induced distal embolism in patients with femoropopliteal artery disease. Between February 2018 and April 2019, consecutive patients (n = 32) who presented with de novo femoropopliteal artery disease and underwent endovascular therapy using DCB were retrospectively reviewed in a single-center study. Patients were divided into two groups based on whether distal embolism was detected using laser doppler flowmetry (DEL group) or not (non-DEL group). Baseline characteristics and 1-year clinical outcomes were compared between the groups. DEL was found in 44% of limbs (DEL group: n = 15, non-DEL group: n = 19). Below-the-knee arterial runoff ≤ 1 (p = 0.033), popliteal lesion (p = 0.044), ambulation difficulty (p = 0.021), and previous history of coronary artery disease (p = 0.013) were identified as predictive factors of DEL. Procedural factors, reference vessel diameter, lesion length, and total drug amount were not predictive of DEL. The overall target lesion restenosis (TLR) rate was 17.4% (n = 5). The TLR rate was not significantly different between the DEL and non-DEL groups (13.3% vs. 15.8%, p = 0.55). Severe calcification was the only significant factor for TLR (4.2% vs. 40.0%, p = 0.02). Among patients with femoropopliteal disease, there was no difference in 1-year clinical outcome between patients who underwent DEL and those who did not.

Shaping of T Cell Functions by Trogocytosis.

Trogocytosis is an active process whereby plasma membrane proteins are transferred from one cell to the other cell in a cell-cell contact-dependent manner. Since the discovery of the intercellular transfer of major histocompatibility complex (MHC) molecules in the 1970s, trogocytosis of MHC molecules between various immune cells has been frequently observed. For instance, antigen-presenting cells (APCs) acquire MHC class I (MHCI) from allografts, tumors, and virally infected cells, and these APCs are subsequently able to prime CD8+ T cells without antigen processing via the preformed antigen-MHCI complexes, in a process called cross-dressing. T cells also acquire MHC molecules from APCs or other target cells via the immunological synapse formed at the cell-cell contact area, and this phenomenon impacts T cell activation. Compared with naïve and effector T cells, T regulatory cells have increased trogocytosis activity in order to remove MHC class II and costimulatory molecules from APCs, resulting in the induction of tolerance. Accumulating evidence suggests that trogocytosis shapes T cell functions in cancer, transplantation, and during microbial infections. In this review, we focus on T cell trogocytosis and the related inflammatory diseases.

Tim4 recognizes carbon nanotubes and mediates phagocytosis leading to granuloma formation.

Macrophage recognition and phagocytosis of crystals is critical for the associated fibrosis and cancer. Of note, multi-walled carbon nanotubes (MWCNTs), the highly representative products of nanotechnology, induce macrophage NLRP3 inflammasome activation and cause asbestosis-like pathogenesis. However, it remains largely unknown how macrophages efficiently recognize MWCNTs on their cell surfaces. Here, we identify by a targeted screening of phagocyte receptors the phosphatidylserine receptors T cell immunoglobulin mucin 4 (Tim4) and Tim1 as the pattern-recognition receptors for carbon crystals. Docking simulation studies reveal spatiotemporally stable interfaces between aromatic residues in the extracellular IgV domain of Tim4 and one-dimensional carbon crystals. Further, CRISPR-Cas9-mediated deletion of Tim4 and Tim1 reveals that Tim4, but not Tim1, critically contributes to the recognition of MWCNTs by peritoneal macrophages and to granuloma development in a mouse model of direct mesothelium exposure to MWCNTs. These results suggest that Tim4 recognizes MWCNTs through aromatic interactions and mediates phagocytosis leading to granulomas.

Hypersensitivity reaction to pegylated liposomal doxorubicin administration for Mullerian carcinoma in Japanese women.

AIM: PEGylated liposomal doxorubicin (PLD) is a therapeutic agent for gynecological malignancy. Hypersensitivity reaction (HSR) is a major adverse effect that usually disappears after halting administration of PLD. Premedication is usually not necessary before administration of PLD to prevent HSR. Here, we evaluated the frequency of HSR during administration of PLD following premedication in Japanese women. METHODS: We performed PLD administration in 78 patients (386 cycles) between 2013 and 2018. Granisetron hydrochloride and dexamethasone sodium phosphate were administered 30 min before PLD administration. Then, PLD (40 or 30 mg/m2 combined usage with carboplatin) was administered. We retrospectively reviewed the medical records of 78 patients and examined the frequency of HSR. RESULTS: Seven of 78 (9%) patients showed HSR by PLD administration following premedication. One patient showed cardiopulmonary arrest in 13 min after PLD administration (grade 4). The other six patients showed grade 2 HSR. All patients developed HSR in the first course. The incidence of HSR was significantly higher in patients with allergic history than in patients without allergic history (p = 0.0151). CONCLUSIONS: Clinicians should be aware of the potential for HSR in patients administered PLD, particularly those with allergic history and those receiving the first cycle of PLD, even following premedication.

Sudden cardiac arrest of a 16-year-old boy with left main coronary artery atresia: a case report.

BACKGROUND: In many cases, the cause of exercise-induced cardiopulmonary arrest in young persons is thought to be fatal arrhythmia, and one of the causes is ischaemic heart disease. Left main coronary artery atresia (LMCAA) is an extremely rare disease in which there is a congenital defect of the left main coronary artery, causing heart failure and exercise-induced angina attacks at a young age. Thus, it is disease that should be differentiated when examining young persons with chest pain. CASE SUMMARY: A 16-year-old boy experienced sudden cardiopulmonary arrest during soccer practice, was brought to our hospital for emergency treatment after return of spontaneous circulation. Elective coronary angiography revealed findings indicating an osmium defect in the left coronary artery (LCA) and blood flow via collateral circulation from the right coronary artery. Contrast-enhanced coronary computed tomography (CT) angiography showed a defect in the LCA ostium and LMCAA was diagnosed in the patient. After coronary artery bypass grafting was performed, but the patient was discharged in an ambulatory state with a wearable cardiac defibrillator. Postoperative course has been favourable. DISCUSSION: Left main coronary artery atresia is an extremely rare disease in which there is a congenital defect of the left main trunk of the coronary artery and should be differentiated when encountering cases of heart failure or exercise-induced angina/arrhythmia attacks in young persons who are not at risk for atherosclerosis. Exercise electrocardiogram may show a false negative result, and therefore coronary CT is useful for diagnosis.

A newly designed 0.018-in.-compatible inner dilator as a novel option for endovascular therapy with the crossover approach.

This study aimed to investigate the efficacy of guiding sheath delivery with the crossover approach using a newly customized inner dilator for a 0.018-in. guidewire of the Destination® guiding sheath (Terumo Corporation, Tokyo, Japan) (18-system), compared with that of the conventional-type 0.035-in. guidewires with inner dilators (35-system), and to predict failure of guiding sheath delivery. We conducted a prospective multicenter case series study of the contralateral crossover approach using Destination®, to determine whether the 18-system could be a rescue system in cases in which the conventional 35-system failed. To evaluate the efficacy of the 18-system, we created an in vitro aortoiliac bifurcation model by using a silicone vessel. We enrolled 172 cases consecutively. The initial crossover approach with the 35-system failed in 37 cases (21.5%), and a second attempt with the 18-system was successful in all failed cases. The bifurcation angles in the 35-system failure cases were significantly steeper than those in the 35-system success cases. A receiver operating characteristic curve analysis demonstrated that an aortoiliac bifurcation angle of 68° was the optimal cut-off value for predicting failure of the crossover procedure. Data from the analysis using the silicone vessel model suggested that the 18-system provided superior results, especially in aortoiliac bifurcation angles steeper than 60°, consistent with the in vivo findings. The results of the initial use of the 18-system with the crossover approach suggest that it may be superior to the conventional 35-system, especially in cases of steeper aortoiliac bifurcation angles.

Retrospective analysis of treatment and prognosis for uterine leiomyosarcoma: 10-year experience of a single institute.

AIM: Uterine leiomyosarcoma (ULMS) is a highly aggressive and lethal disease. This malignancy remains the most common type of uterine sarcoma, affecting approximately 0.4/100 000 women each year. Our aim was to assess the treatment and prognosis of ULMS patients. METHODS: A total of 14 patients were treated at our institution between January 2008 and July 2017. We retrospectively analyzed their clinicopathological variables, treatment and prognosis. RESULTS: The median patient age was 63 years (range, 35-83 years). The largest group of patients had stage IB disease (stage IB, n = 8; IIB, n = 2; IIIB, n = 1; IVB, n = 3) and the largest group by histological subtype was ordinary (ordinary, n = 11; myxoid, n = 2; epithelioid, n = 1). Total abdominal hysterectomy and bilateral salpingo-oophorectomy were performed for all patients, with additional surgical procedures (e.g., tumor resection, lymphadenectomy) performed if necessary. Twelve patients received adjuvant chemotherapy (ACT) consisting of gemcitabine and docetaxel. Ten patients experienced recurrence and received multidisciplinary therapies, including tumor resection, chemotherapy, radiation and targeted therapies. The median observation period was 17 months (range, 5-75 months), and 11 patients were alive (without disease, n = 5; with disease, n = 6). Intriguingly, five of eight stage IB patients who received postoperative ACT were alive without disease. CONCLUSION: ULMS is rare but is associated with a poor prognosis, even if multidisciplinary therapies are administered. However, ACT appears to be effective in improving the prognosis of patients with stage IB disease.

Two types of small cell carcinoma of the ovary: Two typical case reports.

•This report shows very rare cases of small cell carcinoma of the ovary, hypercalcemic type and pulmonary type.•Their chemo sensitivity is quite different. These two cases followed opposite clinical courses.•The first case (SCOHT) progressed rapidly, and showed resistance to chemotherapy and radiotherapy.•The second case (SCOPT) showed sensitivity to chemotherapy and radiotherapy although recurrence was repeated.

A study of treatments and outcomes in elderly women with cervical cancer.

OBJECTIVE: With the population aging, development of safe and effective treatments for elderly patients with cancer is needed. Although old age is considered a poor prognostic factor, this is not only because of the patient's disease condition or response to treatment, but also because of treatment strategy and intensity. The purpose of this study was to clarify the influence of age on treatment and prognosis in patients with cervical cancer. METHODS: Women with stage Ib-IV cervical cancer treated at our institution between 1997 and 2014 were retrospectively analyzed. Patients were stratified by age into groups for analysis, <65 years and ≥65 years. Categorical variables were compared using chi-squared and Fisher's exact tests. Survival analyses were performed using the Kaplan-Meier method, and comparisons were made using the log-rank test. Subsequently, Cox proportional hazards models were developed to find independent prognostic factors. RESULTS: Of 959 patients included in our study, 247 were ≥65 and 712 were <65 years of age. Elderly patients tended to be at a more advanced stage than younger patients (p < 0.001). Elderly patients more commonly had comorbidities. More received standard treatment in the younger patient group at any disease stage than in the elderly patient group (p < 0.001). Similar rates of adverse effects caused by surgery or radiotherapy were seen in patients from both groups. Although overall survival was statistically shorter in elderly patients (74.7 vs. 57.1%, p < 0.001), there was no significant difference in disease-specific survival for patients treated only with standard treatment. In multivariate analyses, clinical stage, histological type, treatment intensity, and primary surgery remained independent prognostic factors. Age was not an independent prognostic factor. CONCLUSIONS: The influence of age on prognosis in patients with cervical cancer was less than we expected. Elderly patients might have better outcomes depending on the type of standard treatment they receive. The appropriate modality and intensity of treatment should be based on the patient's general condition and background.

Improvement in the prognosis of ovarian cancer in the era before addition of molecular targeting therapy.

OBJECTIVE: The prognosis of ovarian cancer has improved because of platinum- and taxane-containing chemotherapy. We investigated the 5-year disease-specific overall survival and prognostic factors of patients with advanced ovarian cancer to elucidate the change in clinical course of ovarian cancer with the advance of chemotherapy for patients who developed relapse in the era before the addition of molecular targeting therapy. METHODS: We reviewed the clinical course of 134 patients with advanced ovarian cancer (FIGO Stage III and IV) treated in the past 11 years (1999-2010). We classified the patients into two groups: those who had been diagnosed with ovarian cancer from 1999 to 2005 (Group A) and those who had been diagnosed from 2006 to 2010 (Group B). We compared the 5-year disease-specific overall survival and median survival rates between these two groups. We also investigated the prognostic factors of 104 patients who developed relapse. RESULTS: The 5-year disease-specific overall survival rate was significantly higher in Group B than A (67.0% vs. 38.6%; P = 0.032). Chemotherapy containing pegylated liposomal doxorubicin hydrochloride, non-clear cell adenocarcinoma and intestinal resection were independent prognostic factors. CONCLUSIONS: The induction of new chemotherapeutic drugs and the increased variation of second- or third-line chemotherapy affected the improvement in overall survival of patients with advanced epithelial ovarian cancer.

Popliteal artery aneurysm treated with implantation of a covered stent graft (fluency(®)) reinforced with a nitinol stent (S.M.A.R.T. (®)).

A 60-year-old man was admitted for right knee pain provoked by an enlarging popliteal artery aneurysm (PAA) after endovascular therapy for thromboembolism in the right popliteal artery. The PAA was treated with implantation of a covered stent graft (Fluency(®)); however, acute thromboembolism occurred 6 months after the intervention. Therefore, we implanted a nitinol stent (S.M.A.R.T.(®)) in the proximal part of the covered stent where the major hinge point existed in addition to a stent fracture. No vascular event occurred during 4.5 years of follow-up.

Stent dislodgement induced by a vasodilator used for severe coronary artery spasm caused by Kounis syndrome.

Coronary stent dislodgement is a rare but critical complication of percutaneous coronary intervention. It can potentially result in serious consequences, such as stent embolization and emergent coronary artery bypass graft surgery. Here, we describe the successful retrieval of an extracoronary dislodged stent, where dislodgement was induced by a vasodilator used for severe coronary artery spasm caused by Kounis syndrome.

A side-grooved guiding sheath as an effective treatment strategy for femoro-popliteal artery lesions.

During revascularization for chronic total occlusion (CTO) of the proximal superficial femoral artery (SFA), the guiding sheath may prolapse out of the common femoral artery (CFA) or may not be fully inserted during treatment. Therefore, we have developed a treatment strategy using a novel side-grooved guiding sheath, whereby a 5.0-Fr guiding sheath (45 cm long) with a 1.0 mm × 5.0 mm rectangular side-groove is inserted into the deep femoral artery, the side-groove is aligned with the bifurcation, and the SFA lesion treatment is performed via the side-groove. This technique provides good stability and maintains the wire's torque performance, while avoiding sheath prolapse from its position in the CFA. We have successfully treated seven cases of SFA-CTO with this guiding sheath, and did not observe any increase in complications, procedure time, or amount of contrast media (vs. the conventional procedure). Therefore, our side-grooved guiding sheath appears to be safe and effective for treating SFA-CTO, and we hope to perform additional development of this technique.

[Nogitecan Hydrochloride Treatment for Patients with Recurrent Ovarian Cancer].

Nogitecan hydrochloride(topotecan)has shown efficacy in patients with recurrent ovarian cancer, but has not been used widely in Japan. We evaluated the efficacy and adverse effects of topotecan in 12 patients (median age, 62 years) treated for recurrent ovarian cancer between 2000 and 2013. Four patients had relapsed after primary treatment, and 8 had relapsed at least twice. Seven patients had been treated with more than 3 prior regimens. Initial treatment of the 12 patients consisted of intravenous topotecan (1.0-1.4 mg/m2/day) for 5 consecutive days. Initial doses were based on previous chemotherapy and/ or renal function, with reduced doses administered to patients with severe adverse effects during prior courses of treatment. The 12 patients received a total of 54 courses of topotecan(range, 1-15 courses). Of these 12 patients, one achieved a partial response and 6 had stable disease. The median time to progression was 14.4 weeks. All 12 patients had grade 3-4 myelosuppression, while none had febrile neutropenia or severe non-hematologic toxicities. Patients who received higher doses or increased courses of chemotherapy had apparently more severe adverse events. These findings suggested that topotecan should be used as a second- or third-line treatment, rather than later, in patients with tumor recurrence, with its dose reduced according to the physical status of each patient. Such strategies may enhance both the efficacy and safety of topotecan in patients with recurrent ovarian cancer.

Immune thrombocytopenia associated with solid cancer.

We describe a case of immune thrombocytopenia (ITP) associated with ovarian cancer. At the patient's first visit to hospital, high platelet-associated IgG and low platelet count (74 × 10(9)/L) were noted on blood test. She was diagnosed as having ITP complicated by ovarian cancer. Four days after surgery, the platelet count had increased to within the normal range. This is the first report of a patient with ITP complicated by ovarian cancer in which the platelet count reverted to normal soon after surgery for the ovarian cancer. We also investigated the characteristics of similar solid cancers with ITP at National Kyushu Cancer Center, Fukuoka, Japan.

Early inflammatory reactions in atherosclerosis are induced by proline-rich tyrosine kinase/reactive oxygen species-mediated release of tumor necrosis factor-alpha and subsequent activation of the p21Cip1/Ets-1/p300 system.

OBJECTIVE: Reactive oxygen species (ROS) are involved in the initial process of atherosclerosis, whereas it remains to be determined how atherogenic stimulus causes ROS-mediated proinflammatory reactions. Here, we focused on proline-rich tyrosine kinase (PYK2)-mediated ROS generation and examined how atherogenic stimulus causes early proinflammatory reactions. METHODS AND RESULTS: PYK2-deficient (knockout [KO]) (PYK2-KO) mice were crossbred with apolipoprotein E (ApoE)-deficient (PYK2-KO/ApoE-KO) mice. PYK2-KO/ApoE-KO mice and endothelial cells (EC) were used for the study. Aortic atherogenic lesions in PYK2-KO/ApoE-KO mice were markedly decreased (55% versus ApoE-KO) after 8 weeks of a Western diet. Aortic PYK2 was activated as early as 7 days after the Western diet, when inflammatory cells were not yet activated. Addition of the proatherogenic oxidized phospholipid lysophosphatidylcholine caused activation of endothelial PYK2. Lysophosphatidylcholine-activated PYK2 induced NADPH oxidase-mediated ROS generation and ROS-mediated synthesis of tumor necrosis factor-α (TNFα), vascular cell adhesion molecule-1 (VCAM-1), monocyte chemotactic protein-1 (MCP-1), and p21Cip1/Ets-1. Neutralizing anti-TNFα antibody or knockdown of p21Cip1/Ets-1 system blocked the induction of VCAM-1 and MCP-1. PYK2 deficiency abolished these ROS-mediated proinflammatory reactions. Further analysis revealed that PYK2/ROS-mediated p21Cip1/Ets-1 activation upregulated the transcription of the MCP-1 gene in collaboration with p300 transcription coactivator. CONCLUSIONS: PYK2 is a key tyrosine kinase activated by high cholesterol exposure, which causes ROS-mediated TNFα release and induces TNFα-dependent expression of proinflammatory molecules via the p21Cip1/Ets-1/p300 transcription system.

Endothelial FGF receptor signaling accelerates atherosclerosis.

Members of the fibroblast growth factor (FGF) family have been clinically applied to the treatment of ischemic diseases because of their strong angiogenic actions. Although tissue ischemia is predominantly caused by atherosclerosis, the roles of endothelial FGF receptors (FGF-Rs) in atherosclerosis remain obscure. We generated endothelial cell (EC)-targeted constitutively active FGF-R2-overexpressing mice, using the Tie2 promoter (Tie2-FGF-R2-Tg), and crossed them with apolipoprotein E (ApoE)-deficient mice (ApoE-KO) to generate Tie2-FGF-R2-Tg/ApoE-deficient mice (Tie2-FGF-R2-Tg/ApoE-KO). After being fed a Western diet for 8 wk, the Tie2-FGF-R2-Tg/ApoE-KO demonstrated 2.0-fold greater atherosclerotic lesion area on the luminal surfaces of the aortas than the ApoE-KO (P < 0.01). The level of p21(Cip1) protein, a cell cycle inhibitor, in the FGF-R2-overexpressing EC was 2.5-fold greater than that in the wild-type (WT) EC at the baseline (P < 0.01). FGF-R2 overexpression in the EC resulted in increased expression of VCAM-1 and ICAM-1, acceleration of apoptosis, and decreased proliferative activity, all of which were normalized by small interfering RNA (siRNA)-mediated knockdown of p21(Cip1) (75% reduction in protein level, P < 0.01). Furthermore, the expression of PDGF-B and Egr-1, a PDGF/p21(Cip1)-inducible transcription factor, in the aortic endothelium of Tie2-FGF-R2-Tg/ApoE-KO was significantly greater than that in ApoE-KO. The proliferation of vascular smooth muscle cells in the aortic media of Tie2-FGF-R2-Tg/ApoE-KO was 2.0-fold higher than that in ApoE-KO (P < 0.01). Thus our study reveals that endothelial FGF-R2 signaling aggravates atherosclerosis by promoting p21(Cip1)-mediated EC dysfunction and cautions against the use of FGF for therapeutic angiogenesis in the setting of atherosclerosis.