ABSTRACT
BACKGROUND: Much of what we know about insulin resistance is based on studies from metabolically active tissues such as the liver, adipose tissue, and skeletal muscle. Emerging evidence suggests that the vascular endothelium plays a crucial role in systemic insulin resistance; however, the underlying mechanisms remain incompletely understood. Arf6 (ADP ribosylation factor 6) is a small GTPase that plays a critical role in endothelial cell function. Here, we tested the hypothesis that the deletion of endothelial Arf6 will result in systemic insulin resistance. METHODS: We used mouse models of constitutive endothelial cell-specific Arf6 deletion (Arf6f/- Tie2Cre+) and tamoxifen-inducible Arf6 knockout (Arf6f/f Cdh5CreER+). Endothelium-dependent vasodilation was assessed using pressure myography. Metabolic function was assessed using a battery of metabolic assessments including glucose and insulin tolerance tests and hyperinsulinemic-euglycemic clamps. We used a fluorescence microsphere-based technique to measure tissue blood flow. Skeletal muscle capillary density was assessed using intravital microscopy. RESULTS: Endothelial Arf6 deletion impaired insulin-stimulated vasodilation in white adipose tissue and skeletal muscle feed arteries. The impairment in vasodilation was primarily due to attenuated insulin-stimulated nitric oxide bioavailability but independent of altered acetylcholine-mediated or sodium nitroprusside-mediated vasodilation. Endothelial cell-specific deletion of Arf6 also resulted in systematic insulin resistance in normal chow-fed mice and glucose intolerance in high-fat diet-fed obese mice. The underlying mechanisms of glucose intolerance were reductions in insulin-stimulated blood flow and glucose uptake in the skeletal muscle and were independent of changes in capillary density or vascular permeability. CONCLUSIONS: Results from this study support the conclusion that endothelial Arf6 signaling is essential for maintaining insulin sensitivity. Reduced expression of endothelial Arf6 impairs insulin-mediated vasodilation and results in systemic insulin resistance. These results have therapeutic implications for diseases that are associated with endothelial cell dysfunction and insulin resistance such as diabetes.
Subject(s)
ADP-Ribosylation Factor 6 , Endothelium , Insulin Resistance , Muscle, Skeletal , Mice , ADP-Ribosylation Factor 6/genetics , ADP-Ribosylation Factor 6/metabolism , Endothelium/metabolism , Mice, Inbred C57BL , Glucose Intolerance , Tamoxifen , Mice, Knockout , Adipose Tissue, White/metabolism , Adipose Tissue, White/pathology , Muscle, Skeletal/blood supply , Muscle, Skeletal/metabolism , Muscle, Skeletal/pathology , Obesity/metabolism , Obesity/pathology , Glucose/metabolism , Diet, High-Fat , Mice, Obese , VasodilationABSTRACT
RATIONALE: Myocardial infarction (MI) is one of the most dangerous adverse cardiovascular events. Our previous study found that lysophosphatidic acid (LPA) is increased in human peripheral blood after MI, and LPA has a protective effect on the survival and proliferation of various cell types. However, the role of LPA and its receptors in MI is less understood. OBJECTIVES: To study the unknown role of LPA and its receptors in heart during MI. METHODS AND RESULTS: In this study, we found that mice also had elevated LPA level in peripheral blood, as well as increased cardiac expression of its receptor LPA2 in the early stages after MI. With adult and neonate MI models in global Lpar2 knockout (Lpar2-KO) mice, we found Lpar2 deficiency increased vascular leak leading to disruption of its homeostasis, so as to impaired heart function and increased early mortality. Histological examination revealed larger scar size, increased fibrosis, and reduced vascular density in the heart of Lpar2-KO mice. Furthermore, Lpar2-KO also attenuated blood flow recovery after femoral artery ligation with decreased vascular density in gastrocnemius. Our study revealed that Lpar2 was mainly expressed and altered in cardiac endothelial cells during MI, and use of endothelial-specific Lpar2 knockout mice phenocopied the global knockout mice. Additionally, adenovirus-Lpar2 and pharmacologically activated LPA2 significantly improved heart function, reduced scar size, increased vascular formation, and alleviated early mortality by maintaining vascular homeostasis owing to protecting vessels from leakage. Mechanistic studies demonstrated that LPA-LPA2 signaling could promote endothelial cell proliferation through PI3K-Akt/PLC-Raf1-Erk pathway and enhanced endothelial cell tube formation via PKD1-CD36 signaling. CONCLUSIONS: Our results indicate that endothelial LPA-LPA2 signaling promotes angiogenesis and maintains vascular homeostasis, which is vital for restoring blood flow and repairing tissue function in ischemic injuries. Targeting LPA-LPA2 signal might have clinical therapeutic potential to protect the heart from ischemic injury.
Subject(s)
Myocardial Infarction , Receptors, Lysophosphatidic Acid , Animals , Cicatrix , Endothelial Cells/metabolism , Endothelium, Vascular/metabolism , Homeostasis , Humans , Lysophospholipids , Mice , Mice, Knockout , Myocardial Infarction/genetics , Phosphatidylinositol 3-Kinases , Receptors, Lysophosphatidic Acid/genetics , Receptors, Lysophosphatidic Acid/metabolism , Ventricular RemodelingABSTRACT
The rise in multidrug-resistant (MDR) organisms portends a serious global threat to the health care system with nearly untreatable infectious diseases, including pneumonia and its often fatal sequelae, acute respiratory distress syndrome (ARDS) and sepsis. Gram-negative bacteria (GNB), including Acinetobacter baumannii, Pseudomonas aeruginosa, and carbapenemase-producing Klebsiella pneumoniae (CPKP), are among the World Health Organization's and National Institutes of Health's high-priority MDR pathogens for targeted development of new therapies. Here, we show that stabilizing the host's vasculature by genetic deletion or pharmacological inhibition of the small GTPase ADP-ribosylation factor 6 (ARF6) increases survival rates of mice infected with A. baumannii, P. aeruginosa, and CPKP. We show that the pharmacological inhibition of ARF6-GTP phenocopies endothelium-specific Arf6 disruption in enhancing the survival of mice with A. baumannii pneumonia, suggesting that inhibition is on target. Finally, we show that the mechanism of protection elicited by these small-molecule inhibitors acts by the restoration of vascular integrity disrupted by GNB lipopolysaccharide (LPS) activation of the TLR4/MyD88/ARNO/ARF6 pathway. By targeting the host's vasculature with small-molecule inhibitors of ARF6 activation, we circumvent microbial drug resistance and provide a potential alternative/adjunctive treatment for emerging and reemerging pathogens.
Subject(s)
Acinetobacter baumannii , Gram-Negative Bacterial Infections , ADP-Ribosylation Factor 6 , Animals , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Drug Resistance, Multiple, Bacterial/genetics , Gram-Negative Bacteria , Gram-Negative Bacterial Infections/drug therapy , Mice , Microbial Sensitivity Tests , Pseudomonas aeruginosaABSTRACT
PURPOSE: Primary open-angle glaucoma (POAG) is the leading cause of irreversible blindness worldwide and mutations in known genes can only explain 5-6% of POAG. This study was conducted to identify novel POAG-causing genes and explore the pathogenesis of this disease. METHODS: Exome sequencing was performed in a Han Chinese cohort comprising 398 sporadic cases with POAG and 2010 controls, followed by replication studies by Sanger sequencing. A heterozygous Ramp2 knockout mouse model was generated for in vivo functional study. RESULTS: Using exome sequencing analysis and replication studies, we identified pathogenic variants in receptor activity-modifying protein 2 (RAMP2) within three genetically diverse populations (Han Chinese, German, and Indian). Six heterozygous RAMP2 pathogenic variants (Glu39Asp, Glu54Lys, Phe103Ser, Asn113Lysfs*10, Glu143Lys, and Ser171Arg) were identified among 16 of 4763 POAG patients, whereas no variants were detected in any exon of RAMP2 in 10,953 control individuals. Mutant RAMP2s aggregated in transfected cells and resulted in damage to the AM-RAMP2/CRLR-cAMP signaling pathway. Ablation of one Ramp2 allele led to cAMP reduction and retinal ganglion cell death in mice. CONCLUSION: This study demonstrated that disruption of RAMP2/CRLR-cAMP axis could cause POAG and identified a potential therapeutic intervention for POAG.
Subject(s)
Glaucoma, Open-Angle/genetics , Receptor Activity-Modifying Protein 2/genetics , Animals , Asian People , COS Cells , Calcitonin Receptor-Like Protein/genetics , Calcitonin Receptor-Like Protein/metabolism , China , Chlorocebus aethiops , Cohort Studies , Cyclic AMP/genetics , Genetic Predisposition to Disease/genetics , Glaucoma, Open-Angle/metabolism , HEK293 Cells , Humans , Male , Mice , Mice, Knockout , Middle Aged , Mutation/genetics , Pedigree , Polymorphism, Single Nucleotide , Receptor Activity-Modifying Protein 2/metabolism , Exome Sequencing/methodsABSTRACT
The lack of distinct morphological features of cryptic species is a hard problem for taxonomy, especially when the taxa are closely related with considerable amounts of ancestral polymorphism. Lately, intensive coalescent-based analyses involving multiple loci have become the preferred method to assess the extent of genetic distinctiveness in otherwise phenotypically similar populations. Previously, phylogenetic studies on Pachyhynobius shangchengensis uncovered five extremely deeply divergent clades, which suggested that this species may be a cryptic species complex. In this study, we used the complete mitochondrial genome data and samples from the entire range of stout salamander (Pachyhynobius), as well as publicly available mitochondrial genomes to assess species boundaries within this genus using a suite of diverse methodologies (e.g. general mixed Yule coalescent model, Automatic Barcode Gap Discovery). The phylogenetic relationships recovered two major groups within P. shangchengensis, with one group formed by four of the six extant populations and corresponding to the central and eastern range of the Dabie mountains, while the other group encompassed two other lineages in the north west of the Dabie mountain range. The species delimitation comparison within Pachyhynobius supported the presence of recognized species within the genus, and consensus was observed across methods for the existence of up to five cryptic species within what has been traditionally considered to be P. shangchengensis. While this implies the existence of four taxa in addition to the described P. shangchengensis species, morphological data and life history information are further required to contribute to the species definition. The observed pattern of genetic variation is likely the outcome of a discontinuous habitat combined with niche conservatism, which produced the sky-island effect observed in Pachyhynobius, and which led to formation of a hidden species diversity in this genus.
Subject(s)
Biodiversity , Genome, Mitochondrial , Urodela/genetics , Animals , China , DNA Barcoding, Taxonomic , Geography , Phylogeny , Species SpecificityABSTRACT
PURPOSE: By comparing short- and long-term outcomes following totally robotic radical distal gastrectomy (TRDG) and robotic-assisted radical distal gastrectomy (RADG), we aimed to assess in which modus operandi patients will benefit more. METHODS: From January 2015 to May 2019, we included 332 patients undergone RADG (237) and TRDG (95). Based on the propensity score matching (PSM), inclusion and exclusion criteria, 246 patients were finally included in the propensity score-matched cohort including RADG group (164) and TRDG group (82). We then compared the short- and long-term outcomes following both groups. RESULTS: Propensity score-matched cohort revealed no significant differences in both groups. Intra-abdominal bleeding, time to pass flatus, postoperative activity time, length of incision hospital stays, and stress response were significantly less in TRDG group than in RADG group. We observed 30 complications in RADG group while 13 complications in TRDG group. There were no significant differences in TRDG group and RADG group in terms of operation time, time for anastomosis, proximal resection, distal resection margin, number of lymph node resection, and total hospitalization cost. Both 3-year overall survival and 3-year disease-free survival were comparable in both groups. CONCLUSIONS: TRDG is a safe and feasible modus operandi profiting from short- and long-term outcomes compared with RADG. As surgeons improving their professional skills, TRDG could serve as the standard procedure for distal locally advanced gastric cancer with D2 lymphadenectomy.
Subject(s)
Gastrectomy/methods , Laparoscopy/methods , Postoperative Complications/epidemiology , Robotic Surgical Procedures/methods , Stomach Neoplasms/surgery , Adult , Aged , Disease-Free Survival , Female , Follow-Up Studies , Gastrectomy/adverse effects , Gastrectomy/instrumentation , Humans , Laparoscopy/adverse effects , Length of Stay/statistics & numerical data , Lymph Node Excision/instrumentation , Lymph Node Excision/methods , Male , Middle Aged , Neoplasm Staging , Operative Time , Postoperative Complications/etiology , Prognosis , Retrospective Studies , Robotic Surgical Procedures/adverse effects , Robotic Surgical Procedures/instrumentation , Stomach/pathology , Stomach/surgery , Stomach Neoplasms/mortality , Stomach Neoplasms/pathology , Time FactorsABSTRACT
The innate immune response is essential for combating infectious disease. Macrophages and other cells respond to infection by releasing cytokines, such as interleukin-1ß (IL-1ß), which in turn activate a well-described, myeloid-differentiation factor 88 (MYD88)-mediated, nuclear factor-κB (NF-κB)-dependent transcriptional pathway that results in inflammatory-cell activation and recruitment. Endothelial cells, which usually serve as a barrier to the movement of inflammatory cells out of the blood and into tissue, are also critical mediators of the inflammatory response. Paradoxically, the cytokines vital to a successful immune defence also have disruptive effects on endothelial cell-cell interactions and can trigger degradation of barrier function and dissociation of tissue architecture. The mechanism of this barrier dissolution and its relationship to the canonical NF-κB pathway remain poorly defined. Here we show that the direct, immediate and disruptive effects of IL-1ß on endothelial stability in a human in vitro cell model are NF-κB independent and are instead the result of signalling through the small GTPase ADP-ribosylation factor 6 (ARF6) and its activator ARF nucleotide binding site opener (ARNO; also known as CYTH2). Moreover, we show that ARNO binds directly to the adaptor protein MYD88, and thus propose MYD88-ARNO-ARF6 as a proximal IL-1ß signalling pathway distinct from that mediated by NF-κB. Finally, we show that SecinH3, an inhibitor of ARF guanine nucleotide-exchange factors such as ARNO, enhances vascular stability and significantly improves outcomes in animal models of inflammatory arthritis and acute inflammation.
Subject(s)
ADP-Ribosylation Factors/metabolism , GTPase-Activating Proteins/metabolism , Myeloid Differentiation Factor 88/metabolism , Receptors, Interleukin/metabolism , ADP-Ribosylation Factor 6 , Adjuvants, Immunologic/pharmacology , Animals , Arthritis/pathology , Cadherins/metabolism , Capillary Permeability/drug effects , Cell Line , Endothelial Cells/drug effects , Enzyme Activation/drug effects , Humans , Interleukin-1beta/pharmacology , NF-kappa B/metabolism , Protein Kinase Inhibitors/pharmacology , Protein Transport/drug effects , Purines/pharmacology , Signal Transduction , Thiophenes/pharmacologyABSTRACT
BACKGROUND: Cerebral cavernous malformation (CCM) is a hemorrhagic stroke disease affecting up to 0.5% of North Americans that has no approved nonsurgical treatment. A subset of patients have a hereditary form of the disease due primarily to loss-of-function mutations in KRIT1, CCM2, or PDCD10. We sought to identify known drugs that could be repurposed to treat CCM. METHODS AND RESULTS: We developed an unbiased screening platform based on both cellular and animal models of loss of function of CCM2. Our discovery strategy consisted of 4 steps: an automated immunofluorescence and machine-learning-based primary screen of structural phenotypes in human endothelial cells deficient in CCM2, a secondary screen of functional changes in endothelial stability in these same cells, a rapid in vivo tertiary screen of dermal microvascular leak in mice lacking endothelial Ccm2, and finally a quaternary screen of CCM lesion burden in these same mice. We screened 2100 known drugs and bioactive compounds and identified 2 candidates, cholecalciferol (vitamin D3) and tempol (a scavenger of superoxide), for further study. Each drug decreased lesion burden in a mouse model of CCM vascular disease by ≈50%. CONCLUSIONS: By identifying known drugs as potential therapeutics for CCM, we have decreased the time, cost, and risk of bringing treatments to patients. Each drug also prompts additional exploration of biomarkers of CCM disease. We further suggest that the structure-function screening platform presented here may be adapted and scaled to facilitate drug discovery for diverse loss-of-function genetic vascular disease.
Subject(s)
Central Nervous System Neoplasms/drug therapy , Disease Models, Animal , Drug Repositioning/methods , Hemangioma, Cavernous, Central Nervous System/drug therapy , Animals , Cells, Cultured , Central Nervous System Neoplasms/pathology , Cholecalciferol/pharmacology , Cholecalciferol/therapeutic use , Drug Screening Assays, Antitumor/methods , Endothelial Cells/drug effects , Endothelial Cells/pathology , Free Radical Scavengers/pharmacology , Free Radical Scavengers/therapeutic use , Hemangioma, Cavernous, Central Nervous System/pathology , Humans , Mice , Mice, Knockout , Mice, Transgenic , Treatment OutcomeABSTRACT
The vascular endothelium responds to infection by destabilizing endothelial cell-cell junctions to allow fluid and cells to pass into peripheral tissues, facilitating clearance of infection and tissue repair. During sepsis, endotoxin and other proinflammatory molecules induce excessive vascular leak, which can cause organ dysfunction, shock, and death. Current therapies for sepsis are limited to antibiotics and supportive care, which are often insufficient to reduce morbidity and prevent mortality. Previous attempts at blocking inflammatory cytokine responses in humans proved ineffective at reducing the pathologies associated with sepsis, highlighting the need for a new therapeutic strategy. The small GTPase ARF6 is activated by a MyD88-ARNO interaction to induce vascular leak through disruption of endothelial adherens junctions. In this study, we show that the MyD88-ARNO-ARF6-signaling axis is responsible for LPS-induced endothelial permeability and is a destabilizing convergence point used by multiple inflammatory cues. We also show that blocking ARF6 with a peptide construct of its N terminus is sufficient to reduce vascular leak and enhance survival during endotoxic shock, without inhibiting the host cytokine response. Our data highlight the therapeutic potential of blocking ARF6 and reducing vascular leak for the treatment of inflammatory conditions, such as endotoxemia.
Subject(s)
ADP-Ribosylation Factors/immunology , Adherens Junctions/immunology , Capillary Permeability/immunology , Endothelial Cells/immunology , Shock, Septic/immunology , Signal Transduction/immunology , ADP-Ribosylation Factor 6 , Adherens Junctions/pathology , Animals , Capillary Permeability/drug effects , Cells, Cultured , Endothelial Cells/pathology , Female , GTPase-Activating Proteins/immunology , Humans , Lipopolysaccharides/toxicity , Male , Mice , Myeloid Differentiation Factor 88/immunology , Shock, Septic/chemically induced , Shock, Septic/pathology , Signal Transduction/drug effectsABSTRACT
Dissemination of HIV in the host involves transit of the virus and virus-infected cells across the lymphatic endothelium. HIV may alter lymphatic endothelial permeability to foster dissemination, but the mechanism is largely unexplored. Using a primary human lymphatic endothelial cell model, we found that HIV-1 envelope protein gp120 induced lymphatic hyperpermeability by disturbing the normal function of Robo4, a novel regulator of endothelial permeability. HIV-1 gp120 induced fibronectin expression and integrin α5ß1 phosphorylation, which led to the complexing of these three proteins, and their subsequent interaction with Robo4 through its fibronectin type III repeats. Moreover, pretreatment with an active N-terminus fragment of Slit2, a Robo4 agonist, protected lymphatic endothelial cells from HIV-1 gp120-induced hyperpermeability by inhibiting c-Src kinase activation. Our results indicate that targeting Slit2/Robo4 signaling may protect the integrity of the lymphatic barrier and limit the dissemination of HIV in the host.
Subject(s)
Endothelium, Lymphatic/metabolism , HIV Envelope Protein gp120/metabolism , HIV Infections/metabolism , Intercellular Signaling Peptides and Proteins/metabolism , Nerve Tissue Proteins/metabolism , Receptors, Cell Surface/metabolism , Signal Transduction , Enzyme Activation , Genes, src , HEK293 Cells , HIV Envelope Protein gp120/genetics , HIV Infections/genetics , Humans , Integrin alpha5beta1/genetics , Integrin alpha5beta1/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Nerve Tissue Proteins/genetics , Permeability , Receptors, Cell Surface/geneticsABSTRACT
BACKGROUND: Signaling through vascular endothelial growth factor C (VEGFC) and VEGF receptor 3 (VEGFR-3) plays a central role in lymphangiogenesis and the metastasis of several cancers via the lymphatics. Recently, the Slit2/Robo4 pathway has been recognized as a modulator of vascular permeability and integrity. Signaling via the Robo receptor inhibits VEGF-mediated effects; however, its effects on lymphatic endothelial cell function have not been well characterized. RESULTS: We found that pretreatment with Slit2N, an active fragment of Slit2, inhibited VEGF-C-mediated lung-derived lymphatic endothelial cell (L-LEC) proliferation, migration, and in vitro tube formation. Slit2N induced the internalization of VEGFR-3, which blocked its activation, and inhibited the activation of the PI3K/Akt pathway by VEGF-C in L-LECs. Moreover, we found that inhibition of VEGF-C-induced effects by Slit2N was Robo4-dependent. CONCLUSION: These results indicate that Slit2N/Robo4 modulates several key cellular functions, which contribute to lymphangiogenesis, and identify this ligand-receptor pair as a potential therapeutic target to inhibit lymphatic metastasis of VEGF-C-overexpressing cancers and manage lymphatic dysfunctions characterized by VEGF-C/VEGFR-3 activation.
Subject(s)
Intercellular Signaling Peptides and Proteins/metabolism , Lymphangiogenesis , Nerve Tissue Proteins/metabolism , Receptors, Cell Surface/metabolism , Vascular Endothelial Growth Factor C/pharmacology , Vascular Endothelial Growth Factor Receptor-3/metabolism , Cell Line , Cell Movement , Cell Proliferation , Endothelial Cells/drug effects , Endothelial Cells/metabolism , Humans , Intercellular Signaling Peptides and Proteins/genetics , Lymphatic Vessels/cytology , Nerve Tissue Proteins/genetics , Peptide Fragments/pharmacology , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Receptors, Cell Surface/genetics , Vascular Endothelial Growth Factor Receptor-3/geneticsABSTRACT
OBJECTIVE: We aimed to investigate the impacts of prolonged mask use on patients with hypertension or diabetes during the COVID-19 pandemic. METHODS: This study included patients with hypertension or diabetes who visited the outpatient department of Nanjing Yimin Hospital between 1 February 2022 and 31 January 2023. We compared the change in blood pressure (BP) and fasting plasma glucose in patients with hypertension or diabetes and adjustments to treatment between the group with prolonged mask-wearing group (≥20 hours/week) and the control group (<20 hours/week). RESULTS: Compared with the control group of hypertensive patients, the prolonged mask-wearing group had significantly higher diastolic blood pressure (DBP) and mean arterial pressure (MAP). These two groups had had similar DBP and MAP 1 year earlier. Likewise, the prolonged mask-wearing group of patients with diabetes had a greater need than the control group for upgraded treatment to reach their therapeutic goals. CONCLUSIONS: This study suggests that prolonged mask use by patients with hypertension or diabetes has negative effects on hypertension and plasma glucose control. BP and plasma glucose monitoring should be improved in these patient populations and their treatment should be adjusted in a timely manner.
Subject(s)
COVID-19 , Diabetes Mellitus, Type 2 , Hypertension , Humans , Diabetes Mellitus, Type 2/drug therapy , Blood Glucose , Masks , Pandemics , Blood Glucose Self-MonitoringABSTRACT
BACKGROUND: The efficacy of laparoscopic surgery (LS) for the treatment of colonoscopic perforation is still controversial. The purpose of this meta-analysis was to evaluate the effectiveness and safety of LS versus open surgery (OS) for colonoscopic perforation. METHODS: All clinical trials that compared laparoscopic with OS for colonoscopic perforation published in English were identified in PubMed, EMBASE, Web of Science, and Cochrane Library searches. A modified scale was used to assess the quality of the literature. We analyzed the age, sex ratio, aim of colonoscopy, history of abdominopelvic surgery, type of procedure, size of perforation, operation time, postoperative fasting time, hospital stay, postoperative complication morbidity, and postoperative mortality. Meta-analyses were performed using weighted mean differences for continuous variables, and odds ratios for dichotomous variables. RESULTS: No eligible randomized trials were identified, but eleven nonrandomized trials were analyzed. In the pooled data of 192 patients who underwent LS and 131 OS, there were no significant differences in age, sex ratio, aim of colonoscopy, history of abdominopelvic surgery, perforation size, and operative time between the groups. LS group had shorter time of hospital stay and postoperative fasting time, less postoperative complication morbidity, but there were no significant difference in postoperative mortality rate between LS group and OS group. CONCLUSIONS: Based on the current meta-analysis, we conclude that LS is a safe and efficacious technique for colonoscopic perforation, with fewer postoperative complications, less hospital mortality, and faster recovery compared with OS.
Subject(s)
Laparoscopy , Humans , Laparoscopy/methods , Colonoscopy/adverse effects , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Colonoscopes , Length of Stay , Treatment OutcomeABSTRACT
Background: Much of what we know about insulin resistance is based on studies from metabolically active tissues such as liver, adipose tissue, and skeletal muscle. Emerging evidence suggests that the vascular endothelium plays a crucial role in systemic insulin resistance, however, the underlying mechanisms remain incompletely understood. ADP ribosylation factor 6 (Arf6) is a small GTPase that plays a critical role in endothelial cell (EC) function. Here, we tested the hypothesis that the deletion of endothelial Arf6 will result in systemic insulin resistance. Methods: We used mouse models of constitutive EC-specific Arf6 deletion (Arf6 f/- Tie2Cre) and tamoxifen inducible Arf6 knockout (Arf6 f/f Cdh5Cre). Endothelium-dependent vasodilation was assessed using pressure myography. Metabolic function was assessed using a battery of metabolic assessments including glucose- and insulin-tolerance tests and hyperinsulinemic-euglycemic clamps. A fluorescence microsphere-based technique was used to measure tissue blood flow. Intravital microscopy was used to assess skeletal muscle capillary density. Results: Endothelial Arf6 deletion impaired insulin-stimulated vasodilation in white adipose tissue (WAT) and skeletal muscle feed arteries. The impairment in vasodilation was primarily due to attenuated insulin-stimulated nitric oxide (NO) bioavailability but independent of altered acetylcholine- or sodium nitroprusside-mediated vasodilation. In vitro Arf6 inhibition resulted in suppressed insulin stimulated phosphorylation of Akt and endothelial NO synthase. Endothelial cell-specific deletion of Arf6 also resulted in systematic insulin resistance in normal chow fed mice and glucose intolerance in high fat diet fed obese mice. The underlying mechanisms of glucose intolerance were reductions in insulin-stimulated blood flow and glucose uptake in the skeletal muscle and were independent of changes in capillary density or vascular permeability. Conclusion: Results from this study support the conclusion that endothelial Arf6 signaling is essential for maintaining insulin sensitivity. Reduced expression of endothelial Arf6 impairs insulin-mediated vasodilation and results in systemic insulin resistance. These results have therapeutic implications for diseases that are associated with endothelial cell dysfunction and insulin resistance such as diabetes.
ABSTRACT
Preventing or effectively treating metastatic uveal melanoma (UM) is critical because it occurs in about half of patients and confers a very poor prognosis. There is emerging evidence that hepatocyte growth factor (HGF) and insulin-like growth factor 1 (IGF-1) promote metastasis and contribute to the striking metastatic hepatotropism observed in UM metastasis. However, the molecular mechanisms by which HGF and IGF-1 promote UM liver metastasis have not been elucidated. ASAP1, which acts as an effector for the small GTPase ARF6, is highly expressed in the subset of uveal melanomas most likely to metastasize. Here, we found that HGF and IGF-1 hyperactivate ARF6, leading to its interaction with ASAP1, which then acts as an effector to induce nuclear localization and transcriptional activity of NFAT1. Inhibition of any component of this pathway impairs cellular invasiveness. Additionally, knocking down ASAP1 or inhibiting NFAT signaling reduces metastasis in a xenograft mouse model of UM. The discovery of this signaling pathway represents not only an advancement in our understanding of the biology of uveal melanoma metastasis but also identifies a novel pathway that could be targeted to treat or prevent metastatic uveal melanoma.
Subject(s)
Melanoma , Uveal Neoplasms , Humans , Animals , Mice , Hepatocyte Growth Factor/genetics , Hepatocyte Growth Factor/metabolism , Insulin-Like Growth Factor I/genetics , Insulin-Like Growth Factor I/metabolism , Melanoma/pathology , Uveal Neoplasms/metabolism , Disease Models, Animal , Adaptor Proteins, Signal Transducing/metabolismABSTRACT
Atherosclerosis is the root cause of major cardiovascular diseases (CVD) such as myocardial infarction and stroke. ADP-ribosylation factor 6 (Arf6) is a ubiquitously expressed GTPase known to be involved in inflammation, vascular permeability and is sensitive to changes in shear stress. Here, using atheroprone, ApoE-/- mice, with a single allele deletion of Arf6 (HET) or wildtype Arf6 (WT), we demonstrate that reduction in Arf6 attenuates atherosclerotic plaque burden and severity. We found that plaque burden in the descending aorta was lower in HET compared to WT mice (pË0.001) after the consumption of an atherogenic Paigen diet for 5 weeks. Likewise, luminal occlusion, necrotic core size, plaque grade, elastic lamina breaks, and matrix deposition were lower in the aortic root atheromas of HET compared to WT mice (all p≤0.05). We also induced advanced human-like complex atherosclerotic plaque in the left carotid artery using partial carotid ligation surgery and found that atheroma area, plaque grade, intimal necrosis, intraplaque hemorrhage, thrombosis, and calcification were lower in HET compared to WT mice (all p≤0.04). Our findings suggest that the atheroprotection afforded by Arf6 heterozygosity may result from reduced immune cell migration (all p≤0.005) as well as endothelial and vascular smooth muscle cell proliferation (both p≤0.001) but independent of changes in circulating lipids (all p≥0.40). These findings demonstrate a critical role for Arf6 in the development and severity of atherosclerosis and suggest that Arf6 inhibition can be explored as a novel therapeutic strategy for the treatment of atherosclerotic CVD.
Subject(s)
Atherosclerosis , Plaque, Atherosclerotic , Animals , Humans , Mice , ADP-Ribosylation Factor 6 , Aorta , Atherosclerosis/genetics , Disease Models, Animal , Mice, Inbred C57BL , Mice, Knockout, ApoE , Necrosis , Plaque, Atherosclerotic/geneticsABSTRACT
BACKGROUND: ARF nucleotide-binding site opener (ARNO) is a guanine nucleotide-exchange factor for ADP-ribosylation factor proteins. ARF nucleotide-binding site opener also binds MyD88, and small-molecule inhibition of ARNO reduces inflammation in animal models of inflammatory arthritis and acute inflammation. However, whether genetic deletion of Arno in mice reduces pathologic inflammation has not yet been reported. Furthermore, its role in the nasal cavity has yet to be investigated. OBJECTIVE: To generate Arno knockout mice and to determine whether genetic loss of ARNO reduces eosinophilic inflammation in the ovalbumin (OVA) murine model of rhinitis. METHODS: Arno knockout mice were generated and wild type and knockout littermates were subjected to the OVA-induced mouse model of rhinosinutitis. Eosinophilic inflammation was assessed through immunofluorescent quantification of EMBP+ eosinophils in the septal mucosa and cytokine expression was assessed by quantitative polymerase chain reaction. RESULTS: Arno knockout mice are viable and fertile without any noted deficits. Arno wild type and knockout mice subjected to the OVA-induced model of rhinitis demonstrated an average of 314.5 and 153.8 EMBP+ cells per mm2 septal tissue, respectively (P < .05). Goblet cells per mm of basal lamina were assessed via Alcian blue and there was no statistically significant difference between Arno wild type and knockout mice. Ovalbumin-induced expression of interleukin-5 (IL-5) was significantly reduced in Arno knockout mice (P < .05). There was no statistically significant reduction in IL-4, IL-13, or eotaxin-1 expression. CONCLUSIONS: These data demonstrate that deletion of Arno reduces eosinophilic inflammation and IL-5 expression in an OVA-induced model of rhinitis.
Subject(s)
Interleukin-5 , Rhinitis , Animals , Disease Models, Animal , GTPase-Activating Proteins , Inflammation/genetics , Interleukin-5/genetics , Interleukin-5/metabolism , Mice , Mice, Knockout , Rhinitis/geneticsABSTRACT
Breakdown of the blood-central nervous system barrier (BCNSB) is a hallmark of many neuroinflammatory disorders, such as multiple sclerosis (MS). Using a mouse model of MS, experimental autoimmune encephalomyelitis (EAE), we show that endothelial-to-mesenchymal transition (EndoMT) occurs in the CNS before the onset of clinical symptoms and plays a major role in the breakdown of BCNSB function. EndoMT can be induced by an IL-1ß-stimulated signaling pathway in which activation of the small GTPase ADP ribosylation factor 6 (ARF6) leads to crosstalk with the activin receptor-like kinase (ALK)-SMAD1/5 pathway. Inhibiting the activation of ARF6 both prevents and reverses EndoMT, stabilizes BCNSB function, reduces demyelination, and attenuates symptoms even after the establishment of severe EAE, without immunocompromising the host. Pan-inhibition of ALKs also reduces disease severity in the EAE model. Therefore, multiple components of the IL-1ß-ARF6-ALK-SMAD1/5 pathway could be targeted for the treatment of a variety of neuroinflammatory disorders.
Subject(s)
Encephalomyelitis, Autoimmune, Experimental , Monomeric GTP-Binding Proteins , Multiple Sclerosis , Activin Receptors/metabolism , Animals , Central Nervous System/metabolism , Mice , Mice, Inbred C57BL , Monomeric GTP-Binding Proteins/metabolism , Neuroinflammatory Diseases , Receptor Protein-Tyrosine Kinases/metabolism , Signal TransductionABSTRACT
BACKGROUND: Natural orifice specimen extraction surgery for colorectal cancer has been introduced in order to reduce the abdominal incision, demonstrating major development potential in minimally invasive surgery. We are conducting this randomized controlled trial to assess whether robotic NOSES is non-inferior to traditional robotic-assisted surgery for patients with colorectal cancer in terms of primary and secondary outcomes. METHOD/DESIGN: Accordingly, a prospective, open-label, randomized controlled, parallel-group, multicenter, and non-inferiority trial will be conducted to discuss the safety and efficacy of robotic natural orifice extraction surgery compared to traditional robotic-assisted surgery. Here, 550 estimated participants will be enrolled to have 80% power to detect differences with a one-sided significance level of 0.025 in consideration of the non-inferiority margin of 10%. The primary outcome is the incidence of surgical complications, which will be classified using the Clavien-Dindo system. DISCUSSION: This trial is expected to reveal whether robotic NOSES is non-inferior to traditional robotic-assisted surgery, which is of great significance in regard to the development of robotic NOSES for patients with colorectal cancer in the minimally invasive era. Furthermore, robotic NOSES is expected to exhibit superiority to traditional robotic-assisted surgery in terms of both primary and secondary outcomes. TRIAL REGISTRATION: ClinicalTrials.gov NCT04230772 . Registered on January 15, 2020.
Subject(s)
Colorectal Neoplasms , Laparoscopy , Robotic Surgical Procedures , Colorectal Neoplasms/surgery , Humans , Laparoscopy/adverse effects , Minimally Invasive Surgical Procedures , Multicenter Studies as Topic , Prospective Studies , Randomized Controlled Trials as Topic , Research Design , Robotic Surgical Procedures/adverse effects , Treatment OutcomeABSTRACT
In recent years, the incidence of gastrointestinal cancer has remained high. Currently, surgical resection is still the most effective method for treating gastrointestinal cancer. Traditionally, radical surgery depends on open surgery. However, traditional open surgery inflicts great trauma and is associated with a slow recovery. Minimally invasive surgery, which aims to reduce postoperative complications and accelerate postoperative recovery, has been rapidly developed in the last two decades; it is increasingly used in the field of gastrointestinal surgery and widely used in early-stage gastrointestinal cancer. Nevertheless, many operations for gastrointestinal cancer treatment are still performed by open surgery. One reason for this may be the challenges of minimally invasive technology, especially when operating in narrow spaces, such as within the pelvis or near the upper edge of the pancreas. Moreover, some of the current literature has questioned oncologic outcomes after minimally invasive surgery for gastrointestinal cancer. Overall, the current evidence suggests that minimally invasive techniques are safe and feasible in gastrointestinal cancer surgery, but most of the studies published in this field are retrospective studies and case-matched studies. Large-scale randomized prospective studies are needed to further support the application of minimally invasive surgery. In this review, we summarize several common minimally invasive methods used to treat gastrointestinal cancer and discuss the advances in the minimally invasive treatment of gastrointestinal cancer in detail.