ABSTRACT
PURPOSE: This study aims to explore the correlation between PET and CMR in integrated [68Ga]Ga-FAPI-04 PET/CMR multimodal imaging and its value in the diagnosis and risk assessment of hypertrophic cardiomyopathy (HCM). METHODS: This study included 20 HCM patients and 11 age- and gender-matched controls. PET analysis evaluated left ventricular (LV) [68Ga]Ga-FAPI-04 uptake, including SUVmax, TBR, cardiac fibroblast activity (CFA) and volume (CFV), and total SUV of the 16 segments. CMR tissue characterization parameters included cardiac function, myocardial thickness, late gadolinium enhancement (LGE), relaxation time, extracellular volume (ECV), and peak strain parameters. The 5-year sudden cardiac death (SCD) risk score and the 2-year and 5-year atrial fibrillation (AF) risk scores were calculated for each patient. The study analyzed differences between HCM patients and controls, the correlation between [68Ga]Ga-FAPI-04 PET and concurrent CMR imaging results, and the predictive value of PET/CMR. RESULT: The FAPI uptake, myocardial mass, myocardial thickness, and T1/T2 mapping values were significantly higher in HCM patients compared to controls. Twenty HCM patients and their 320 myocardial segments were discussed. Increased [68Ga]Ga-FAPI-04 uptake in the left ventricular wall was observed in 95% (19/20) of the patients, covering 48.8% (156/320) of the segments. On concurrent CMR, 80% (16/20) of the patients showed LGE, including 95 (29.7%) segments. The FAPI(+)LGE(+) segments exhibited the highest myocardial PET uptake, greatest thickness, longest T1/T2 native values, largest ECV value and the greatest loss of myocardial strain capacity (P < 0.05). There was a significant correlation between FAPI uptake and CMR parameters (P < 0.05). Higher [68Ga]Ga-FAPI-04 uptake showed a positive correlation with SCD and AF risk scores (P < 0.05). The number of LGE(+) segments, mapping parameters, and ECV values in CMR also had prognostic significance. Combining PET with CMR aided in further risk stratification of HCM. CONCLUSION: [68Ga]Ga-FAPI-04 PET/CMR multimodal imaging has potential value in the detection of damaged myocardial lesions and risk assessment of HCM patients. [68Ga]Ga-FAPI-04 PET can detect more affected myocardium compared to CMR, and segments with abnormalities in both PET and CMR show more severe myocardial damage.
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OBJECTIVE: The study aimed to investigate the early results of directional femoral ultrasound-guided compression technique (UCT) using in percutaneous mechanical thrombectomy (PMT) for acute deep vein thrombosis (DVT). METHODS: Consecutive single-center patients with acute iliofemoral DVT who underwent PMT from January 2020 to December 2021 were included. Directional femoral UCT was used to adjust the PMT catheter into the residual thrombus in the inguinal region by ultrasound compression to improve the thrombus clearance rate. Patients were retrospectively analyzed and divided into 2 groups based on PMT with or without directional femoral UCT. The primary efficacy outcome was the incidence of post-thrombotic syndrome (PTS) at 24-month follow-up. The secondary efficacy outcomes included common femoral venous thrombus removal grade, total thrombus removal grade, venous primary patency rate, and incidence of moderate-to-severe PTS at 24-month follow-up. The safety outcomes included complications, major bleeding events, and death at 24-month follow-up. RESULTS: A total of 96 patients were included in the study: 42 patients underwent PMT with directional femoral UCT and 54 patients underwent PMT without UCT. There was no significant difference in baseline characteristics between the 2 groups. The percentages of patients achieved common femoral venous thrombus removal grade 3 and total thrombus removal grade 3 were significantly higher in the PMT with UCT group than those in the PMT without UCT group (p<0.001). The 24-month primary patency rate was significantly higher in the PMT with UCT group than that in the PMT without UCT group (90.0% vs 71.2%, p=0.027). The incidence of PTS was significantly lower in the PMT with UCT group (10.0%) than that in the PMT without UCT group (28.8%) (p=0.027). CONCLUSION: PMT with directional femoral UCT could improve the thrombus clearance rate and primary patency rate of acute iliofemoral DVT and might decrease the incidence of PTS compared to traditional PMT treatment without UCT. CLINICAL IMPACT: Residual thrombus in common femoral vein is a difficult problem associated with higher incidence of PTS. Few studies have focused on common femoral venous thrombus clearance. PMT with directional femoral UCT could improve the thrombus clearance rate and primary patency rate of acute iliofemoral DVT, and might decrease the incidence of PTS compared to traditional PMT treatment without UCT. Directional femoral UCT is recommended in PMT treatment of acute iliofemoral DVT.
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PURPOSE: To evaluate the safety and efficacy of Innospring® stent, a novel self-expanding interwoven nitinol stent, in treating femoropopliteal atherosclerotic lesions. METHODS: A prospective, single-center, single-arm, first-in-human study enrolled 15 patients (mean age 73.1 years; 13 men) to evaluate the safety and efficacy of the Innospring® stent monitored by core laboratories. The inclusion criteria were claudication or ischemic rest pain, de novo lesions or nonstented restenosis, >70% stenosis, lesion length <20 cm, and a reference vessel diameter of 4-7 mm. The primary safety endpoint was 30-day major adverse events. The primary efficacy end point was stent patency at 12 months. Follow-up evaluations were conducted at 30 days, 6 months, and 12 months. RESULTS: The lesion length was 6.1 ± 3.5 mm. Fourteen (93.3%) patients had lesions of the superficial femoral artery and 3 (20.0%) patients had lesions of the popliteal artery. Nine (60.0%) patients had moderate-to-severe calcified lesion. Technical and procedural success was 100%. No patients experienced major adverse events in the first 30 days. The Rutherford category showed significant and sustained improvement at 6 and 12 months. The 12-month follow-up radiographs obtained in 13 patients confirmed the absence of stent fractures in 100% of examinations. The cumulative primary stent patency rate at 6 and 12 months were 93.3% and 84.6%, respectively. CONCLUSION: Stenting of the superficial femoral and popliteal arteries using the Innospring® stent is safe and effective. This competing interwoven nitinol stent may provide superior stent integrity and fracture-resistance as well as serve areas under extreme mechanical stress. CLINICAL IMPACT: Endovascular recanalization is a widely accepted and recommended treatment for symptomatic peripheral artery diseases. The Innospring® stent is a novel self-expanding interwoven stent containing eight nitinol wires with additional radial force, fracture-resistance, and visibility under fluoroscopy. This first-in-human study using the Innospring® stent in patients with femoropopliteal occlusive disease reported that stenting of the superficial femoral and popliteal arteries using the Innospring® stent is safe and effective. This competing interwoven nitinol stent may provide an impressive stent integrity and fracture-resistance as well as serve areas under extreme mechanical stress.
ABSTRACT
Cytoplasmic male sterility (CMS) has been widely used in crop cross breeding. There has been much research on wheat CMS. However, the correlation between S-type CMS and mitochondrial genome remains elusive. Herein, we sequenced the mitochondrial genome of wheat CMS line and compared it with the maintainer line. The results showed that the mitochondrial genome of CMS line encoded 26 tRNAs, 8 rRNAs, and 35 protein-coding genes, and the cob encoding complex III in which the protein coding gene is mutated. This protein is known to affect reactive oxygen (ROS) production. The analysis of ROS metabolism in developing anthers showed that the deficiency of antioxidants and antioxidant enzymes in the sterile system aggravated membrane lipid oxidation, resulting in ROS accumulation, and influencing the anther development. Herein, cob is considered as a candidate causative gene sequence for CMS.
Subject(s)
Genome, Mitochondrial , Triticum , Antioxidants , Electron Transport Complex III/genetics , Electron Transport Complex III/metabolism , Gene Expression Regulation, Plant , Membrane Lipids , Oxygen/metabolism , Plant Breeding , Plant Infertility/genetics , Reactive Oxygen Species/metabolism , Triticum/genetics , Triticum/metabolismSubject(s)
Arterial Occlusive Diseases , Drug-Eluting Stents , Peripheral Arterial Disease , Arterial Occlusive Diseases/diagnostic imaging , Arterial Occlusive Diseases/surgery , Femoral Artery/diagnostic imaging , Humans , Peripheral Arterial Disease/diagnostic imaging , Peripheral Arterial Disease/therapy , Popliteal Artery/diagnostic imaging , Popliteal Artery/surgery , Stents , Treatment Outcome , Vascular PatencyABSTRACT
ABSTRACT: A 57-year-old man with primary aldosteronism exhibited multiple nodules in the left adrenal, pancreatic tail, and splenic region. The left adrenal nodule showed positive 68 Ga-pentixafor and negative 68 Ga-FAPI-04 uptake, suggesting an aldosterone-producing adrenal adenoma. The nodule in the pancreatic tail exhibited high 68 Ga-pentixafor and low 68 Ga-FAPI-04 uptake, similarity with the nodule in splenic region, indicating accessory splenic nodule. Postoperative pathology confirmed an adrenal cortical adenoma and an accessory splenic nodule in the pancreas. This case underscores the complementary role of 68 Ga-pentixafor and 68 Ga-FAPI-04 PET/MR in diagnosing complex adrenal and pancreatic pathologies.
Subject(s)
Aldosterone , Magnetic Resonance Imaging , Positron-Emission Tomography , Humans , Male , Middle Aged , Aldosterone/metabolism , Multimodal Imaging , Spleen/diagnostic imaging , Spleen/metabolism , Adenoma/diagnostic imaging , Adenoma/metabolism , Adrenal Gland Neoplasms/diagnostic imaging , Gallium RadioisotopesABSTRACT
ABSTRACT: A 70-year-old woman presented with left ovarian mass and thickened peritoneum. 18F-FDG PET/CT showed no significant FDG-avid in the whole body. 68Ga-FAPI-04 demonstrated abnormally high FAPI uptake in the ileocecal region, left ovarian lesion, and thickened peritoneum. The postoperative pathology confirmed the appendiceal goblet cell adenocarcinoma. This case highlights the superior and innovative diagnostic role of 68Ga-FAPI-04 in appendiceal goblet cell adenocarcinoma and its metastases.
ABSTRACT
Androgen deprivation therapy (ADT) is the first line of treatment for metastatic prostate cancer (PCa) that effectively delays the tumor progression. However, it also increases the risk of venous thrombosis event (VTE) in patients, a leading cause of mortality. How a pro-thrombotic cascade is induced by ADT remains poorly understood. Here, we report that protein disulfide isomerase A2 (PDIA2) is upregulated in PCa cells to promote VTE formation and enhance PCa cells resistant to ADT. Using various in vitro and in vivo models, we demonstrated a dual function of PDIA2 that enhances tumor-mediated pro-coagulation activity via tumor-derived extracellular vehicles (EVs). It also stimulates PCa cell proliferation, colony formation, and xenograft growth androgen-independently. Mechanistically, PDIA2 activates the tissue factor (TF) on EVs through its isomerase activity, which subsequently triggers a pro-thrombotic cascade in the blood. Additionally, TF-containing EVs can activate the Src kinase inside PCa cells to enhance the AR signaling ligand independently. Androgen deprivation does not alter PDIA2 expression in PCa cells but enhances PDIA2 translocation to the cell membrane and EVs via suppressing the clathrin-dependent endocytic process. Co-recruitment of AR and FOXA1 to the PDIA2 promoter is required for PDIA2 transcription under androgen-deprived conditions. Importantly, blocking PDIA2 isomerase activity suppresses the pro-coagulation activity of patient plasma, PCa cell, and xenograft samples as well as castrate-resistant PCa xenograft growth. These results demonstrate that PDIA2 promotes VTE and tumor progression via activating TF from tumor-derived EVs. They rationalize pharmacological inhibition of PDIA2 to suppress ADT-induced VTE and castrate-resistant tumor progression.
Subject(s)
Disease Progression , Prostatic Neoplasms, Castration-Resistant , Protein Disulfide-Isomerases , Venous Thrombosis , Animals , Humans , Male , Mice , Androgen Antagonists/pharmacology , Androgen Antagonists/adverse effects , Cell Line, Tumor , Cell Proliferation/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Prostatic Neoplasms, Castration-Resistant/pathology , Prostatic Neoplasms, Castration-Resistant/metabolism , Prostatic Neoplasms, Castration-Resistant/genetics , Prostatic Neoplasms, Castration-Resistant/drug therapy , Protein Disulfide-Isomerases/metabolism , Protein Disulfide-Isomerases/genetics , Receptors, Androgen/metabolism , Receptors, Androgen/genetics , Thromboplastin/metabolism , Thromboplastin/genetics , Venous Thrombosis/metabolism , Venous Thrombosis/chemically induced , Venous Thrombosis/pathology , Venous Thrombosis/genetics , Venous Thrombosis/etiology , Xenograft Model Antitumor AssaysABSTRACT
The fluorescence enhancement in broadband Cr-doped fibers (CDFs) fabricated by a drawing tower with a redrawn powder-in-tube preform is proposed and demonstrated. The CDFs after heat treatment exhibited Cr4⺠emission enhancement with spectral density of 200 pW/nm, verified by the formation of α-Mg2SiO4 nanocrystalline structures in the core of CDFs. The high fluorescence achievement in the CDFs is essential to develop a broadband CDF amplifier for next-generation optical communication systems.
Subject(s)
Chromium/chemistry , Fiber Optic Technology/instrumentation , Equipment Design , Equipment Failure Analysis , FluorescenceABSTRACT
Hepatocellular carcinoma (HCC) is one of the most critical health problems in the world. For proper treatment, it is important to identify the grade of cancer morbidity from HCC biopsy image. The diagnostic work is not only time-consuming but also subjective. The same biopsy image may be diagnosed as of different grades by different doctors, due to lack of experience or difference in opinion. In this work, we proposed an automatic grading system with classification accuracy matching to an experienced doctor, to help augment the diagnosis process. First, we proposed a segmentation method to isolate all nucleus-like objects present in a biopsy image. Non-target objects (here the target is a single HCC nucleus) present in the biopsy image are isolated too in the segmentation process. To eliminate such non-target objects, we proposed clustering of segmented images and a novel method to filter out target objects. Next, we proposed a two track neural network, where input consists of 2 different images. It combines a single segmented nucleus and a random cropped texture patch of the biopsy image to which the nucleus belongs. At this classifier output, we grade the single nucleus. Finally, a majority voting method is used to identify the grade of the whole biopsy image. We achieved an accuracy of 99.03% for nucleus image grading and 99.66% accuracy for grading biopsy images.
Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Humans , Algorithms , Liver Neoplasms/pathology , Neural Networks, Computer , Biopsy , Image Processing, Computer-Assisted/methodsABSTRACT
Concrete cracking is a significant issue in the global construction industry, and the restraint stress of concrete is a crucial contributing factor to early concrete cracking. The addition of magnesium oxide additive (MEA) to concrete is a method to enhance its crack resistance. In this paper, concrete specimens with four different contents of MEA were tested with a temperature stress testing machine. The deformation characteristics and mechanical properties of concrete with varying contents of MEA were investigated using both free deformation tests and fully constrained deformation tests. The prediction model for the early restrained stress of concrete was developed by integrating the stress relaxation phenomenon of concrete with models for autogenous shrinkage, temperature deformation, and elastic modulus. According to the results, (1) the thermal expansion coefficient exhibits a pattern of initially increasing and subsequently decreasing with the increasing ratio of MEA; (2) the addition of 3% and 8% MEA can offset 23% and 35.1% of the concrete's self-shrinkage, respectively. Nevertheless, when the added MEA content is 5%, the self-shrinkage of concrete increases by 6%; (3) the addition of 3-8% MEA can result in a 0.5-1.67 times increase in the maximum expansion stress of concrete, as well as a 0.5-0.95 times increase in cracking stress; (4) as the MEA content continues to increase, the stress relaxation level of concrete also increases. In comparison to concrete mixed without MEA, the maximum increase in the stress relaxation level of concrete is 65.5%, thereby enhancing the concrete's anti-cracking ability. However, when the MEA dosage reaches a certain threshold, the stress relaxation enhancement brought about by the addition of MEA will no longer be significant; (5) when compared to the experimental data, the established model of early-age constraint stress accurately predicts the tensile constraint stress of concrete.
ABSTRACT
Phenotypic switch of vascular smooth muscle cells (VSMCs) plays an important role in the pathogenesis of atherosclerosis. The mRNA expression of the synthetic biomarker Collagen Type I Alpha 1 Chain (COL1A1) gene is upregulated during the switch of VSMCs from the contractile to the synthetic phenotype. The association of noncoding circular RNAs transcribed by the COL1A1 gene with VSMC phenotype alteration and atherogenesis remains unclear. Here we reported a COL1A1 circular RNA (circCOL1A1) which is specifically expressed in VSMCs and is upregulated during phenotype alteration of VSMCs. CircCOL1A1 is also detectable in the serum or plasma. Healthy vascular tissues have a low expression of CircCOL1A1, while it is upregulated in atherosclerosis patients. Through ex vivo and in vitro assays, we found that circCOL1A1 can promote VSMC phenotype switch. Mechanistic analysis showed that circCOL1A1 may exert its function as a competing endogenous RNA of miR-30a-5p. Upregulation of circCOL1A1 ameliorates the inhibitory effect of miR-30a-5p on its target SMAD1, which leads to suppression of transforming growth factor-ß (TGF-ß) signaling. Our findings demonstrate that circCOL1A1 promotes the phenotype switch of VSMCs through the miR-30a-5p/SMAD1/TGF-ß axis and it may serve as a novel marker of atherogenesis or as a therapeutic target for atherosclerosis.
Subject(s)
Atherosclerosis , MicroRNAs , Humans , Atherosclerosis/metabolism , Cell Movement , Cell Proliferation , Cells, Cultured , MicroRNAs/metabolism , Muscle, Smooth, Vascular , Myocytes, Smooth Muscle/pathology , Phenotype , RNA, Circular/genetics , RNA, Circular/metabolism , Transforming Growth Factor beta/metabolismABSTRACT
Vascular intimal hyperplasia (VIH) is an important stage of atherosclerosis (AS), in which macrophages not only play a critical role in local inflammation, but also transform into foam cells to participate into plaque formation, where they appear to be heterogeneous. Recently, it was shown that CD11c+ macrophages were more associated with active plaque progression. However, the molecular regulation of phenotypic changes of plaque macrophages during VIH has not been clarified and thus addressed in the current study. Since CD11c- cells were M2a-polarized anti-inflammatory macrophages, while CD11c+ cells were M1/M2b-polarized pro-inflammatory macrophages, we used bioinformatics tools to analyze the CD11c+ versus CD11c- plaque macrophages, aiming to detect the differential genes associated with M1/M2 macrophage polarization. We obtained 122 differential genes that were significantly altered in CD11c+ versus CD11c- plaque macrophages, regardless of CD11b expression. Next, hub genes were predicted in these 122 genes, from which we detected 3 candidates, interleukin 6 (Il6), Decorin (Dcn) and Tissue inhibitor matrix metalloproteinase 1 (Timp1). The effects of these 3 genes on CD11c expression as well as on the macrophage polarization were assessed in vitro, showing that only expression of Il6, but not expression of Dcn or Timp1, induced M1/M2b-like polarization in M2a macrophages. Moreover, only suppression of Il6, but not suppression of either of Dcn or Timp1, induced M2a-like polarization in M1/M2b macrophages. Furthermore, pharmaceutical suppression of Il6 attenuated VIH formation and progression of AS in a mouse model that co-applied apolipoprotein E-knockout and high-fat diet. Together, our data suggest that formation of VIH can be controlled through modulating macrophage polarization, as a promising therapeutic approach for prevent AS.
Subject(s)
Atherosclerosis , Interleukin-6 , Macrophage Activation , Macrophages , Plaque, Atherosclerotic , Tunica Intima , Animals , Atherosclerosis/genetics , Atherosclerosis/immunology , Atherosclerosis/pathology , Hyperplasia/genetics , Hyperplasia/immunology , Hyperplasia/pathology , Interleukin-6/genetics , Interleukin-6/immunology , Macrophage Activation/genetics , Macrophage Activation/immunology , Macrophages/immunology , Macrophages/pathology , Mice , Plaque, Atherosclerotic/genetics , Plaque, Atherosclerotic/immunology , Plaque, Atherosclerotic/pathology , Tunica Intima/immunology , Tunica Intima/pathologyABSTRACT
BACKGROUND: Numerous studies have explored whether serum beta 2-microglobulin (ß2-MG) can be used as a biomarker for monitoring systemic lupus erythematosus (SLE) disease activity, but the results are conflicting. Therefore, we performed a systematic meta-analysis to further investigate the correlation between serum ß2-MG level and SLE disease activity. METHODS: PubMed, Web of Science, Embase, and CNKI databases were thoroughly searched for eligible studies through April 2022. Standardized mean differences with 95% confidence intervals (95% CIs) were used to depict the differences in serum ß2-MG levels between groups compared in the studies. The correlation between serum ß2-MG level and SLE disease activity was assessed using Fisher z-values. RESULTS: Sixteen articles with combined 1368 SLE patients were included in this meta-analysis. Serum ß2-MG levels were significantly higher in SLE patients than in healthy controls (pooled standardized mean difference: 3.98, 95% CI: 2.50-5.46, Pâ <â .01). In addition, patients with active SLE had an increased serum ß2-MG concentration compared to their inactive SLE counterparts. Furthermore, a positive correlation was observed between serum ß2-MG levels and SLE disease activity (pooled Fisher zâ =â 0.78, 95% CI: 0.61-0.96, Pâ <â .01). CONCLUSIONS: This study suggests that patients with SLE have higher serum ß2-MG levels than healthy controls and that serum ß2-MG levels are positively correlated with SLE disease activity. Thus, serum ß2-MG level may be a promising biomarker for monitoring SLE disease activity.
Subject(s)
Lupus Erythematosus, Systemic , beta 2-Microglobulin , Biomarkers , Humans , Patient ComplianceABSTRACT
Several previously proposed deep learning methods to design amino acid sequences that autonomously fold into a given protein backbone yielded promising results in computational tests but did not outperform conventional energy function-based methods in wet experiments. Here we present the ABACUS-R method, which uses an encoder-decoder network trained using a multitask learning strategy to predict the sidechain type of a central residue from its three-dimensional local environment, which includes, besides other features, the types but not the conformations of the surrounding sidechains. This eliminates the need to reconstruct and optimize sidechain structures, and drastically simplifies the sequence design process. Thus iteratively applying the encoder-decoder to different central residues is able to produce self-consistent overall sequences for a target backbone. Results of wet experiments, including five structures solved by X-ray crystallography, show that ABACUS-R outperforms state-of-the-art energy function-based methods in success rate and design precision.
ABSTRACT
The infectious pancreatic necrosis virus (IPNV) belongs to the Birnaviridae family of viruses and causes acute contagious diseases in a number of economically important freshwater and marine fish. In this study, we infected zebrafish embryonic cells (ZF4) with IPNV and analyzed the gene expression patterns of normal and infected cells using quantitative real-time PCR. We identified a number of immune response genes, including ifna, ifng, mx, irf1, irf2, irf4, tnfa, tnfb, il-1b, il-15, il-26, ccl4 and mmp family genes, that are induced after viral infection. Transcriptional regulators, including cebpb, junb, nfkb and stat1, stat4 and stat5, were also upregulated in IPNV-infected cells. In addition, we used Pathway Studio software to identify TNFα as having the greatest downstream influence among these altered genes. Treating virus-infected cells with an siRNA targeting TNFα inhibited NF-κB expression. To further interrupt the TNFα/NF-κB-mediated pathway, the expression levels of cytokines and metalloproteinases were inhibited in IPNV-infected cells. These data suggest that, during IPNV infection, the expression of cytokines and metalloproteinases might be initiated through the TNFα/NF-κB-mediated pathway. The modulation of TNFα/NF-κB-related mechanisms may provide a therapeutic strategy for inhibiting viral infection in teleosts.
Subject(s)
Birnaviridae Infections/veterinary , Cytokines/metabolism , Fish Diseases/immunology , Infectious pancreatic necrosis virus/immunology , Metalloproteases/metabolism , NF-kappa B/metabolism , Signal Transduction , Tumor Necrosis Factor-alpha/metabolism , Zebrafish/immunology , Animals , Birnaviridae Infections/immunology , Cell Line , Cytokines/genetics , Cytokines/immunology , Fish Proteins/genetics , Fish Proteins/immunology , Fish Proteins/metabolism , Gene Expression Profiling , Metalloproteases/genetics , Metalloproteases/immunology , NF-kappa B/genetics , NF-kappa B/immunology , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/immunology , Up-Regulation , Zebrafish/genetics , Zebrafish/metabolism , Zebrafish/virologyABSTRACT
BACKGROUND: Vascular smooth muscle cells (VSMC) switch to macrophage-like cells after cholesterol loading, and this change may play an important role in atherogenesis. Muscleblind-like splicing regulator 1 (MBNL1) is a well-known splicing factor that has been implicated in many cellular processes. However, the role of MBNL1 in VSMC macrophage-like transdifferentiation is largely unknown. In this study, we aim to characterize the role of MBNL1-induced gene splicing during atherogenesis. METHODS: The expression of MBNL1 and Abelson interactor 1 (Abi1) splice variants (Abi1-e10 and Abi1-Δe10) was compared between artery tissues from healthy donors and atherosclerosis patients. Regulatory mechanisms of MBNL1-induced Abi1 gene splicing were studied, and the signal pathways mediated by Abi1 splice variants were investigated in VSMC. RESULTS: Loss of MBNL1 was found in the macrophage-like VSMC (VSMC-M) in artery wall from atherosclerosis patients. In vitro and in vivo evidence confirmed that Abi1 is one of the MBNL1 target genes. Loss of MBNL1 significantly induces the Abi1-Δe10 isoform expression. Compared to the known actin organization activities of the Abi1 gene, we discovered a novel action of Abi1-Δe10, whereby Abi1-Δe10 activates Rac1 independent of upstream stimulation and triggers the Rac1-NOX1-ROS pathway, which results in increased expression of transcription factor Kruppel-like factor 4 (KLF4). While Abi1-Δe10 inhibits contractile VSMC biomarkers expression and cell contraction, it stimulates VSMC proliferation, migration and macrophage-like transdifferentiation. CONCLUSION: Loss-of-function of MBNL1 activates VSMC-M transdifferentiation to promote atherogenesis through regulating Abi1 RNA splicing.
Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Cytoskeletal Proteins/genetics , Muscle, Smooth, Vascular/metabolism , RNA Splicing , RNA-Binding Proteins/metabolism , Actins/metabolism , Adaptor Proteins, Signal Transducing/metabolism , Atherosclerosis/metabolism , Atherosclerosis/pathology , Cell Dedifferentiation , Cells, Cultured , Cytoskeletal Proteins/metabolism , Humans , Kruppel-Like Factor 4 , Kruppel-Like Transcription Factors/metabolism , Macrophages/cytology , Macrophages/metabolism , Muscle, Smooth, Vascular/cytology , NADPH Oxidase 1/antagonists & inhibitors , NADPH Oxidase 1/genetics , NADPH Oxidase 1/metabolism , Phenotype , Protein Isoforms/metabolism , RNA Interference , RNA, Small Interfering/metabolism , RNA-Binding Proteins/antagonists & inhibitors , RNA-Binding Proteins/genetics , Reactive Oxygen Species/metabolism , Signal Transduction , rac1 GTP-Binding Protein/metabolismABSTRACT
BACKGROUND AND AIMS: Phenotypic switch of vascular smooth muscle cells (VSMC) plays a key role in the pathogenesis of atherosclerosis and restenosis after artery intervention. Transcription repressor element 1-silencing transcription factor (REST) has been identified as key regulator of VSMC proliferation. In the present study, we sought to investigate the potential association of E3-ubiquitin ligase ß-TRCP mediated REST protein degradation with Kv1.3 expression during VSMC phenotypic switch. METHODS: Protein and mRNA expression was measured in ex vivo and in vitro models. Protein interaction and ubiquitination were analyzed by immunoprecipitation assays. ChIP assays were performed to assess the relationship between REST and targeted DNA binding site. RESULTS: We found that the expression level of E3-ubiquitin ligase ß-TRCP is significantly increased during VSMC phenotypic switch. REST protein ubiquitination mediated by ß-TRCP is critical for VSMC proliferation and migration. We also found that the gene KCNA3 encoding potassium channel protein Kv1.3 contains a functional REST binding site and is repressed by REST. Downregulation of REST by ß-TRCP and consequently upregulation of Kv1.3 are important events during VSMC phenotypic switch. Furthermore, upregulated Kv1.3 accelerates ß-TRCP modulated REST degradation through Erk1/2 signaling. CONCLUSIONS: Our results reveal a fundamental role for regulatory interactions between ß-TRCP modulated REST degradation and Kv1.3 in the control of the multilayered regulatory programs required for VSMC phenotype switch.
Subject(s)
Kv1.3 Potassium Channel/metabolism , Muscle, Smooth, Vascular , Repressor Proteins/metabolism , beta-Transducin Repeat-Containing Proteins/metabolism , Animals , Humans , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Phenotype , Proteolysis , beta-Transducin Repeat-Containing Proteins/geneticsABSTRACT
miR-122, a hepato-specific microRNA (miRNA), is frequently down-regulated in human hepatocellular carcinoma (HCC). In an effort to identify novel miR-122 targets, we performed an in silico analysis and detected a putative binding site in the 3'-untranslated region (3'-UTR) of Bcl-w, an anti-apoptotic Bcl-2 family member. In the HCC-derived cell lines, Hep3B and HepG2, we confirmed that miR-122 modulates Bcl-w expression by directly targeting binding site within the 3'-UTR. The cellular mRNA and protein levels of Bcl-w were repressed by elevated levels of miR-122, which subsequently led to reduction of cell viability and activation of caspase-3. Thus, Bcl-w is a direct target of miR-122 that functions as an endogenous apoptosis regulator in these HCC-derived cell lines.
Subject(s)
Apoptosis Regulatory Proteins/metabolism , Apoptosis , Carcinoma, Hepatocellular/metabolism , Liver Neoplasms/metabolism , MicroRNAs/physiology , 3' Untranslated Regions , Apoptosis Regulatory Proteins/genetics , Base Sequence , Carcinoma, Hepatocellular/genetics , Caspase 3/metabolism , Cell Survival , Down-Regulation , Enzyme Activation , Genetic Vectors , Humans , Liver Neoplasms/genetics , MicroRNAs/genetics , Molecular Sequence Data , RNA, Small Interfering/genetics , TransfectionABSTRACT
Myostatin, a member of the TGF-beta superfamily, is a potent negative regulator of skeletal muscle and growth. Previously, we reported Mstn1 from zebrafish and studied its influence on muscle development. In this study, we identified another form of Myostatin protein which is referred to as Mstn2. The size of Mstn2 cDNA is 1342 bp with 109 and 132 bp of 5' and 3'-untranslated regions (UTRs), respectively. The coding region is 1101 bp encoding 367 amino acids. The identity between zebrafish Mstn1 and 2 is 66%. The phylogenetic tree revealed that the Mstn2 is an ancestral form of Mstn1. To study the functional aspects, we overexpressed mstn2 and noticed that embryos became less active and the juveniles with bent and curved phenotypes when compared to the control. The RT-PCR and in situ hybridization showed concurrent reduction of dystrophin associated protein complex (DAPC). In cryosection and in situ hybridization, we observed the disintegration of somites, lack of transverse myoseptum and loss of muscle integrity due to the failure of muscle attachment in mstn2 overexpressed embryos. Immunohistochemistry and western blot showed that there was a reduction of dystrophin, dystroglycan and sarcoglycan at translational level in overexpressed embryos. Taken together, these results indicate the suitability of zebrafish as an excellent animal model and our data provide the first in vivo evidence of muscle attachment failure by the overexpression of mstn2 and it leads to muscle loss which results in muscle dystrophy that may contribute to Duchenne syndrome and other muscle related diseases.