Development and validation of a novel endovascular thrombectomy device to treat deep vein thrombosis: a preclinical study in a swine model.

This study evaluated the safety and efficacy of a novel endovascular thrombectomy device in a swine model of deep vein thrombosis (DVT). The device has an over-the-wire configuration, a manually expandable catching basket, a funnel sheath with a covered stent to minimize the risk of microembolization, and an integrated delivery system. DVT was induced by occluding the right iliac vein with a balloon catheter and injecting thrombin. The novel device was inserted into the inferior vena cava through the right jugular vein access. The device effectively removed the thrombus, restoring venous patency without residual thrombus, vessel injury, or complications. These findings suggest the potential advantages of the novel device over predicate devices. Further clinical evaluation is needed to establish the efficacy of this device in human patients with DVT.

The inhibition of Wnt signaling attenuates RANKL-induced osteoclastogenic macrophage activation.

Abdominal aortic aneurysms (AAAs) have been linked to the activation of osteoclastogenic macrophages. Reports have suggested that Wnt signaling has a dual effect of proliferation and differentiation during osteoclastogenesis. The Wnt/ß-Catenin pathway is a critical regulator of cell pluripotency, cell survival, and cell fate decisions. It regulates cell proliferation and differentiation through transcriptional co-activators, CBP, and p300, respectively. The inhibition of ß-catenin suppresses proliferation but induces differentiation of osteoclast precursor cells. This study aimed to examine the effect of ICG-001, a ß-catenin/CBP-specific Wnt signaling inhibitor, on osteoclastogenesis by inhibiting proliferation without inducing differentiation. To induce osteoclastogenesis, RAW 264.7 macrophages were stimulated with a soluble receptor activator of NF-κB ligand (RANKL). The effect of Wnt signaling inhibition was examined by treating macrophages with or without ICG-001 during RANKL stimulation. The activation and differentiation of macrophages were examined through western blotting, quantitative PCR, and tartrate-resistant acid phosphate (TRAP) staining in vitro. The relative expression level of the nuclear factor of activated T-cells cytoplasmic 1 protein was significantly suppressed by ICG-001 treatment. The relative expression levels of mRNA of TRAP, cathepsin K, and matrix metalloproteinase-9 were significantly lower in the ICG-001-treated group. The number of TRAP-positive cells decreased in the ICG-001-treated group relative to the non-treated group. The inhibition of Wnt signaling pathway via ICG-001 suppressed osteoclastogenic macrophage activation. Our previous studies have shown the importance of osteoclastogenic macrophage activation in AAA. Further research to examine the therapeutic potential of ICG-001 on AAA is warranted.

Unpacking the Complexities of a Silent Killer.

An abdominal aortic aneurysm (AAA) is a life-threatening condition that affects millions of people worldwide [...].

Antioxidants and azd0156 Rescue Inflammatory Response in Autophagy-Impaired Macrophages.

Autophagy is a lysosomal degradation system that eliminates and recycles damaged intracellular organelles and proteins. Inflammatory macrophages play a critical role in the development of various age-related inflammatory illnesses such as abdominal aortic aneurysm, atherosclerosis, and rheumatoid arthritis; therefore, identifying the mechanisms that cause macrophage inflammation is crucial for a better understanding of and developing therapeutics for inflammatory diseases. Previous research has linked autophagy to macrophage inflammation; Atg16L1-deficient macrophages increase IL-1 and IL-18 production via inflammasome activation. In this study, however, we show an alternative pathway of macrophage inflammation in an autophagy-deficient environment. We found that inhibiting autophagy in THP1 macrophages progressively increased the expression of p65-mediated inflammatory genes. This effect was reversed by treatment with antioxidants or azd0156, an ataxia telangiectasia mutated (ATM) inhibitor. In addition, our results showed that M1 macrophages inhibit autophagy and induce DNA damage, whereas M2 macrophages activate autophagy and reduce DNA damage. Importantly, the chemical activation of autophagy or ATM inhibition during M1 polarization reduced the M1 phenotype and inflammation, whereas inhibiting autophagy during M2 polarization also reduced the M2 phenotype. Thus, our findings highlight the importance of the autophagy-ATM pathway in driving macrophage inflammation.

Induction of endoplasmic reticulum stress markers in an acromegaly model.

Acromegaly is a growth hormone (GH) excess pathological condition in humans. Acromegaly is associated with somatic disfigurement and a wide range of systemic manifestations such as arthritis, neuropathy, carpal tunnel syndrome, reproductive disorders, metabolic disorders, and gastrointestinal complications. The influence of excess GH on the cellular level could aid in understanding the root causes of acromegaly-related health complications. Previously, we found that GH excess induces DNA damage to somatic cells and reduces the stem cells number and causes premature aging. In this study, an in-depth analysis of the acromegaly RNAseq data revealed the disruption of important biological cellular processes. Gene set enrichment analysis, heatmap, and enrichment analysis of acromegaly RNAseq data revealed induction of endoplasmic reticulum (ER) stress markers in various organs. Interestingly, the induction of ER stress was even more apparent than in aged zebrafish. Splicing of box-binding protein-1 (XBP1) mRNA is a hallmark of ER stress. Therefore, we quantified spliced XBP1 mRNA in different organs of our acromegaly model. Thus, our study emphasizes the importance of ER stress in GH oversecretion, which is important for understanding the health complications of acromegaly.

Effects of Ultrafine Single-Nanometer Oxygen Bubbles on Radiation Sensitivity in a Tumor-Bearing Mouse Model.

Radiation therapy against cancer cells often causes radiation resistance via accumulation of hypoxia-inducible factor 1 subunit alpha (HIF-1α) under hypoxic conditions and severe side effects. Radiation sensitizers without side effects are required to overcome hypoxia-induced radiation resistance and decrease radiation-related side effects in patients with refractory cancer. We previously developed oxygen nanobubble water (NBO2 water) and demonstrated that it suppresses hypoxia-induced radiation resistance in cancer cell lines within the single-nanometer range. This study aimed to elucidate whether NBO2 water could act as a radiosensitizer via regulation of HIF-1α in a tumor-bearing mouse model. Six-week-old female BALB/c mice subcutaneously injected with tumor cells received control water or NBO2 water for 28 days, after which biochemical examinations and radiation treatment were performed. Hypoxic tumor regions were detected immunohistochemically. We found that NBO2 water sensitized radiation reactivity in the xenografted tumors. Notably, NBO2 water administration downregulated the accumulation of HIF-1α in xenografted tumors and did not affect the vital organs of healthy mice. The combination of radiation and single-nanometer NBO2 water without severe side effects may be a promising therapeutic option to improve radiation sensitivity in cancer patients without tolerance to invasive treatments.

A histopathological classification scheme for abdominal aortic aneurysm disease.

OBJECTIVE: Two consensus histopathological classifications for thoracic aortic aneurysms (TAAs) and inflammatory aortic diseases have been issued to facilitate clinical decision-making and inter-study comparison. However, these consensus classifications do not specifically encompass abdominal aortic aneurysms (AAAs). Given its high prevalence and the existing profound pathophysiologic knowledge gaps, extension of the consensus classification scheme to AAAs would be highly instrumental. The aim of this study was to test the applicability of, and if necessary to adapt, the issued consensus classification schemes for AAAs. METHODS: Seventy-two AAA anterolateral wall samples were collected during elective and emergency open aneurysm repair performed between 2002 and 2013. Histologic analysis (hematoxylin and eosin and Movat Pentachrome) and (semi-quantitative and qualitative) grading were performed in order to map the histological aspects of AAA. Immunohistochemistry was performed for visualization of aspects of the adaptive and innate immune system, and for a more detailed analysis of atherosclerotic lesions in AAA. RESULTS: Because the existing consensus classification schemes do not adequately capture the aspects of AAA disease, an AAA-specific 11-point histopathological consensus classification was devised. Systematic application of this classification indicated several universal features for AAA (eg, [almost] complete elastolysis), but considerable variation for other aspects (eg, inflammation and atherosclerotic lesions). CONCLUSIONS: This first multiparameter histopathological AAA consensus classification illustrates the sharp histological contrasts between thoracic and abdominal aneurysms. The value of the proposed scoring system for AAA disease is illustrated by its discriminatory capacity to identify samples from patients with a nonclassical (genetic) variant of AAA disease.

Injectable Hydrogel Capable of In Situ Covalent Crosslinking for Permanent Embolization.

Vascular embolization provides an effective approach for the treatment of hemorrhage, aneurysms, and other vascular abnormalities. However, current embolic materials, such as metallic coils and liquid embolic agents, are limited by their inability to provide safe, consistent, and controlled embolization. Here, we report an injectable hydrogel that can remain at the injection site and subsequently undergo in situ covalent crosslinking, leading to the formation of a dual-crosslinking network (DCN) hydrogel for endovascular embolization. The DCN hydrogel is simple to prepare, easy to deploy via needles and catheters, and mechanically stable at the target injection site, thereby avoiding embolization of nontarget vessels. It possesses efficient hemostatic activity and good biocompatibility. The DCN hydrogel is also clearly visible under X-ray imaging, thereby allowing for targeted embolization. In vivo tests in a rabbit artery model demonstrates that the DCN hydrogel is effective in achieving immediate embolization of the target artery with long-term occlusion by inducing luminal fibrosis. Collectively, the DCN hydrogel provides a viable, biocompatible, and cost-effective alternative to existing embolic materials with clinical translation potential for endovascular embolization.

Role of FOXM1 in vascular smooth muscle cell survival and neointima formation following vascular injury.

BACKGROUND: Accelerated smooth muscle cell (SMC) proliferation is the primary cause of intimal hyperplasia (IH) following vascular interventions. Forkhead Box M1 (FOXM1) is considered a proliferation-associated transcription factor. However, the presence and role of FOXM1 in IH following vascular injury have not been determined. OBJECTIVE: We examined the expression of FOXM1 in balloon-injured rat carotid arteries and investigated the effect of FOXM1 inhibition in SMCs and on the development of IH. METHODS AND RESULTS: FOXM1 was detected by immunofluorescent staining in balloon-injured rat carotid arteries where we observed an upregulation at day 7, 14, and 28 compared to uninjured controls. Immunofluorescence staining revealed FOXM1 coincided with proliferating cell nuclear antigen (PCNA). FOXM1 was also detectable in human carotid plaque samples. Western blot showed an upregulation of FOXM1 protein in serum-stimulated SMCs. Inhibition of FOXM1 using siRNA or chemical inhibition led to the induction of apoptosis as measured by flow cytometry and western blot for cleaved caspase 3. Perturbations in survival signaling were measured by western blot following FOXM1 inhibition, which showed a decrease in phosphorylated AKT and ß-catenin. The chemical inhibitor thiostrepton was delivered by intraperitoneal injection in rats that underwent balloon injury and led to reduced intimal thickening compared to DMSO controls. CONCLUSIONS: FOXM1 is an important molecular mediator of IH that contributes to the proliferation and survival of SMCs following vascular injury.

Spinal Cord Ischemia Rescue after Hybrid Total Arch Repair with Frozen Elephant Trunk: A Case Report.

Frozen elephant trunk repair is a technique described to simplify total arch repair for Stanford type A aortic dissection. Spinal cord ischemia is a devastating complication after frozen elephant trunk repair. In this report, we describe a case of spinal cord ischemia resulting in paralysis after frozen elephant trunk repair. Our spinal cord ischemia protocol was implemented and rescued patients from paraplegia. We report a dedicated spinal cord ischemia protocol that can rescue patients from paraplegia after hybrid arch repair with frozen elephant trunk.

Osteoclast-Like Cells in Aneurysmal Disease Exhibit an Enhanced Proteolytic Phenotype.

Abdominal aortic aneurysm (AAA) is among the top 20 causes of death in the United States. Surgical repair is the gold standard for AAA treatment, therefore, there is a need for non-invasive therapeutic interventions. Aneurysms are more closely associated with the osteoclast-like catabolic degradation of the artery, rather than the osteoblast-like anabolic processes of arterial calcification. We have reported the presence of osteoclast-like cells (OLCs) in human and mouse aneurysmal tissues. The aim of this study was to examine OLCs from aneurysmal tissues as a source of degenerative proteases. Aneurysmal and control tissues from humans, and from the mouse CaPO4 and angiotensin II (AngII) disease models, were analyzed via flow cytometry and immunofluorescence for the expression of osteoclast markers. We found higher expression of the osteoclast markers tartrate-resistant acid phosphatase (TRAP), matrix metalloproteinase-9 (MMP-9), and cathepsin K, and the signaling molecule, hypoxia-inducible factor-1α (HIF-1α), in aneurysmal tissue compared to controls. Aneurysmal tissues also contained more OLCs than controls. Additionally, more OLCs from aneurysms express HIF-1α, and produce more MMP-9 and cathepsin K, than myeloid cells from the same tissue. These data indicate that OLCs are a significant source of proteases known to be involved in aortic degradation, in which the HIF-1α signaling pathway may play an important role. Our findings suggest that OLCs may be an attractive target for non-surgical suppression of aneurysm formation due to their expression of degradative proteases.

Digoxin Attenuates Receptor Activation of NF-κB Ligand-Induced Osteoclastogenesis in Macrophages.

BACKGROUND: Even though hypoxia-inducible factor-1α (HIF-1α) is among the transcriptional factors demonstrated to contribute to the formation of abdominal aortic aneurysms (AAAs), the precise mechanism has been unclear. Digoxin is known as an inhibitor of HIF-1α, and shows a protective effect against the progression of AAAs. OBJECTIVES: We tested the effect of digoxin on osteoclastogenesis (OCG) and examined the pathway through which digoxin exerts inhibition of HIF-1α. MATERIALS AND METHODS: RAW 264.7 macrophage cells were cultured and stimulated by soluble receptor activator of NF-κB ligand (sRANKL) with or without digoxin. First, we tested the effect of digoxin to attenuate macrophage activation, which led to OCG, characterized by tartrate-resistant acid phosphatase (TRAP)-positive macrophages (TPMs). RESULTS: The activation of TPMs stimulated by sRANKL was attenuated by digoxin treatment. Furthermore, the receptor activator of NF-κB (RANK)/receptor activator of NF-κB ligand (RANKL) complex signaling pathway, which is stimulated by HIF-1α, was downregulated by digoxin treatment. CONCLUSIONS: These results show that digoxin attenuates OCG. By inhibition of HIF-1α, digoxin decreases OCG through the downregulation of the RANK/RANKL signaling pathway. Therefore, digoxin is a potential candidate for medical treatment of AAAs.

Cigarette Smoke Extract Activates Tartrate-Resistant Acid Phosphatase-Positive Macrophage.

BACKGROUND: It has been reported that smoking is one of the strongest positive risk factors for abdominal aortic aneurysms (AAAs). Although many studies have been directed to decipher the effect of smoking on AAA, its effect on macrophage activation has not yet been explored. OBJECTIVES: We have reported the importance of osteoclastogenesis (OCG) in aneurysm formation. Therefore, we examined the effect of cigarette smoking on OCG and arterial aneurysmal formation by using cigarette smoke extract (CSE) in this study. METHODS: Macrophage cell lines were stimulated with CSE, and their activation and differentiation were examined in vitro. Since macrophages activated through the OCG pathway are identified by tartrate-resistant acid phosphatase (TRAP) expression, these cells are referred to as TRAP-positive macrophages (TPMs) in this study. We also applied CSE-contained PBS in the calcium chloride-induced mouse carotid aneurysm model in vivo. RESULTS: Macrophages stimulated with CSE expressed significantly higher levels of nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), TRAP, cathepsin K, matrix metalloproteinase-9 and membrane-type metalloproteinase (MT1-MMP). CSE-treated mouse aneurysms showed increased aneurysm size with increased TPM infiltration and protease expression compared to non-CSE-treated mouse aneurysms. CONCLUSIONS: These results suggest that CSE intensifies OCG in macrophages and promotes arterial aneurysmal progression.

Case report of retrograde in situ fenestration of the thoracic stent graft with reentry device in a patient with aortobronchial fistula.

RATIONALE: In situ fenestration may be necessary to preserve branch arteries during thoracic endovascular aortic repair (TEVAR) when there is an inadequate landing zone. PATIENT CONCERNS: We report the case of a 74-year-old man presenting with recurrent hemoptysis. DIAGNOSES: Based on computed tomography (CT) angiogram and bronchoscopy, diagnosis was aorto-bronchial fistula. INTERVENTIONS: We performed retrograde in situ fenestration with reentry catheter (Pioneer Plus, Volcano Corporation, San Diego, CA) to preserve the left subclavian artery following TEVAR for aorto-bronchial fistula. OUTCOMES: Following this procedure, the patient had a patent left subclavian artery and no evidence of endoleak. The patient had no further episodes of hemoptysis. LESSONS: The retrograde in situ fenestration with reentry catheter strategy is an option for patients when carotid-subclavian bypass is deemed unsafe.

RANKL-mediated osteoclastogenic differentiation of macrophages in the abdominal aorta of angiotensin II-infused apolipoprotein E knockout mice.

OBJECTIVE: Osteoclastogenic activation of macrophages (OCG) occurs in human abdominal aortic aneurysms (AAAs) and in calcium chloride-induced degenerative AAAs in mice, which have increased matrix metalloproteinase activity. As the activity of OCG in dissecting aneurysms is not clear, we tested the hypothesis that OCG contributes to angiotensin II (Ang II)-induced dissecting aneurysm (Ang II-induced AAA) in apolipoprotein E knockout mice. METHODS: AAAs were produced in apolipoprotein E knockout mice via the administration of Ang II. Additionally, receptor activator of nuclear factor kB ligand (RANKL)-neutralizing antibody (5 mg/kg) was administered to one group of mice 7 days prior to Ang II infusion. Aneurysmal sections were probed for presence of RANKL and tartrate-resistant acid phosphatase via immunohistochemistry and immunofluorescence staining. Mouse aortas were also examined for RANKL and matrix metalloproteinase 9 expression via Western blot. In vitro murine vascular smooth muscle cells (MOVAS) and murine macrophages (RAW 264.7) were analyzed for the expression of osteogenic factors via Western blot, qPCR, and flow cytometry in response to Ang II or RANKL stimulation. The signaling pathway that mediates Ang II-induced RANKL expression in MOVAS cells was also investigated via application of TG101348, a Janus kinase 2 (JAK2) inhibitor, and Western blot analysis. RESULTS: Immunohistochemical staining of Ang II-induced AAA sections revealed OCG as evidenced by increased RANKL and tartrate-resistant acid phosphatase expression compared with control mice. Immunofluorescence staining of AAA sections revealed co-localization of vascular smooth muscle cells and RANKL, revealing vascular smooth muscle cells as one potential source of RANKL. Systemic administration of RANKL-neutralizing antibody suppressed Ang II-induced AAA, with significant reduction of the maximum diameter of the abdominal aorta compared with vehicle controls (1.5 ± 0.4 mm vs 2.2 ± 0.2 mm). Ang II (1 µM) treatment induced a significant increase in RANKL messenger RNA expression levels in MOVAS cells compared with the vehicle control (1.0 ± 0.2 vs 2.8 ± 0.2). The activities of JAK2 and signal transducer and activator of transcription 5 (STAT5) were also significantly increased by Ang II treatment. Inhibition of JAK2/STAT5 suppressed Ang II-induced RANKL expression, suggesting the involvement of the JAK2/STAT5 signaling pathway. CONCLUSIONS: OCG with increased RANKL expression was present in Ang II-induced AAA, and neutralization of RANKL suppressed AAA formation. As neutralization of RANKL has been used clinically to treat osteoporosis and other osteoclast-related diseases, additional study of the effectiveness of RANKL neutralization in AAA is warranted.

Development of single nanometer-sized ultrafine oxygen bubbles to overcome the hypoxia-induced resistance to radiation therapy via the suppression of hypoxia-inducible factor­1α.

Radiation therapy can result in severe side-effects, including the development of radiation resistance. The aim of this study was to validate the use of oxygen nanobubble water to overcome resistance to radiation in cancer cell lines via the suppression of the hypoxia-inducible factor 1-α (HIF­1α) subunit. Oxygen nanobubble water was created using a newly developed method to produce nanobubbles in the single-nanometer range with the ΣPM-5 device. The size and concentration of the oxygen nanobubbles in the water was examined using a cryo-transmission electron microscope. The nanobubble size was ranged from 2 to 3 nm, and the concentration of the nanobubbles was calculated at 2x1018 particles/ml. Cell viability and HIF-1α levels were evaluated in EBC­1 lung cancer and MDA­MB­231 breast cancer cells treated with or without the nanobubble water and radiation under normoxic and hypoxic conditions in vitro. The cancer cells grown in oxygen nanobubble-containing media exhibited a clear suppression of hypoxia-induced HIF­1α expression compared to the cells grown in media made with distilled water. Under hypoxic conditions, the EBC­1 and MDA­MB231 cells displayed resistance to radiation compared to the cells cultured under normoxic cells. The use of oxygen nanobubble medium significantly suppressed the hypoxia-induced resistance to radiation compared to the use of normal medium at 2, 6, 10 and 14 Gy doses. Importantly, the use of nanobubble media did not affect the viability and radiation sensitivity of the cancer cell lines, or the non­cancerous cell line, BEAS­2B, under normoxic conditions. This newly created single-nanometer range oxygen nanobubble water, without any additives, may thus prove to be a promising agent which may be used to overcome the hypoxia-induced resistance of cancer cells to radiation via the suppression of HIF-1α.

Osteoclastogenesis in Abdominal Aortic Aneurysms: A New Therapeutic Target.

Abdominal aortic aneurysms (AAA) are a major cause of death. Currently, the mainstay of treatment for AAA is surgical repair and there are no FDA approved medical therapies for AAA. Much research is in progress to discover new medical therapies for AAA. The pathophysiology of AAA is understood to be a complex interplay of inflammatory and proteolytic processes that degenerate the aneurysm wall. Arterial calcification, which is observed in AAA but to a lesser extent than in arterial occlusive disease, occurs in a highly regulated manner in a similar process as mineral deposition in bone. Osteoblasts-like cells are responsible for mineral deposition in atherosclerotic plaques. Recently, osteoclast-like cells - the catabolic counterpart to osteoblasts - were discovered in atherosclerotic plaques. Additionally, osteoclast-like cells are present in the wall of AAA but not in healthy aortas. Osteoclast-like cells secrete matrix metalloproteinases (MMP) - proteases implicated in arterial aneurysm wall degeneration - and may contribute to the degredation of the aneurysm wall. Inhibiting osteoclast-like cells may prevent aneurysm progression by reducing tissue levels of MMPs. In this review, we discuss the pathophysiology of AAA formation and the current role of medical therapy in treatment of AAA. Furthermore, we highlight the emerging hypothesis that osteoclasts play a key role in the development of AAA and discuss therapies to inhibit osteoclastogenesis in AAA.

Hyperglycemia attenuates receptor activator of NF-κB ligand-induced macrophage activation by suppressing insulin signaling.

BACKGROUND: Although male gender, aging, hypertension, dyslipidemia, and smoking are common risk factors for abdominal aortic aneurysm, diabetes mellitus is an independent negative risk factor. In aneurysm tissue, matrix metalloproteinases (MMPs) expressed by activated macrophages degrades extracellular matrix proteins. In our previous experimental study, we demonstrated that the aneurysmal formation and macrophage activity were suppressed by inhibiting mimicking hyperglycemia (HG) through upregulation of glucose-sensing nuclear receptor, Nr1h2. Here in this study, we focused on the role of HG-induced altered glucose uptake on macrophage activation. METHODS: RAW264.7 murine macrophage cells were pretreated in cultures containing HG (HG group, 15.5 mM) or normal glucose (NG) concentrations (NG group, 5.5 mM) for 7 d. The culture medium was then changed in both groups to NG conditions, and the cells were stimulated with recombinant murine soluble receptor activator of NF-κB ligand (sRANKL). Macrophage activation was confirmed by tartrate-resistant acid phosphatase (TRAP) staining. RESULTS: Compared with the NG group, MMP-9 expression in the HG group was significantly suppressed. Glucose uptake was increased in the NG group but not in the HG group during macrophage activation. To determine the mechanism of activation, we studied the expression and distribution of glucose transporters (Gluts) in the macrophages. Although Glut expression was unaffected by glucose pretreatment, membrane translocation of Glut-1 was significantly enhanced in macrophages in the NG group but not in the HG group during activation. Insulin receptor and insulin receptor substrate-1 (IRS-1) messenger RNA, known stimulate to membrane translocation of Gluts, were both decreased by the HG condition but not by the NG condition. CONCLUSIONS: HG pretreatment suppressed the macrophage activation. sRANKL increased macrophage glucose uptake at NG concentrations, which was impaired by HG pretreatment through the inhibition of Glut1 membrane translocation and the insulin receptor and IRS-1 gene transcription. These data suggest that HG suppressed macrophage activation, through attenuation of glucose uptake via the suppression of the membrane translocation of Glut1 and insulin signaling.