Autocrine phosphatase PDP2 inhibits ferroptosis by dephosphorylating ACSL4 in the Luminal A Breast Cancer.

Phosphatases can dephosphorylate phosphorylated kinases, leading to their inactivation, and ferroptosis is a type of cell death. Therefore, our aim is to identify phosphatases associated with ferroptosis by analyzing the differentially expressed genes (DEGs) of the Luminal A Breast Cancer (LumABC) cohort from the Cancer Genome Atlas (TCGA). An analysis of 260 phosphatase genes from the GeneCard database revealed that out of the 28 DEGs with high expression, only the expression of pyruvate dehydrogenase phosphatase 2 (PDP2) had a significant correlation with patient survival. In addition, an analysis of DEGs using gene ontology, Kyoto Encyclopedia of Genes and Genomes and gene set enrichment analysis revealed a significant variation in the expression of ferroptosis-related genes. To further investigate this, we analyzed 34 ferroptosis-related genes from the TCGA-LumABC cohort. The expression of long-chain acyl-CoA synthetase 4 (ACSL4) was found to have the highest correlation with the expression of PDP2, and its expression was also inversely proportional to the survival rate of patients. Western blot experiments using the MCF-7 cell line showed that the phosphorylation level of ACSL4 was significantly lower in cells transfected with the HA-PDP2 plasmid, and ferroptosis was correspondingly reduced (p < 0.001), as indicated by data from flow cytometry detection of membrane-permeability cell death stained with 7-aminoactinomycin, lipid peroxidation, and Fe2+. Immunoprecipitation experiments further revealed that the phosphorylation level of ACSL4 was only significantly reduced in cells where PDP2 and ACSL4 co-precipitated. These findings suggest that PDP2 may act as a phosphatase to dephosphorylate and inhibit the activity of ACSL4, which had been phosphorylated and activated in LumABC cells. Further experiments are needed to confirm the molecular mechanism of PDP2 inhibiting ferroptosis.

Engineering Co-N-Cr Cross-Interfacial Electron Bridges to Break Activity-Stability Trade-Off for Superdurable Bifunctional Single Atom Oxygen Electrocatalysts.

Atomically dispersed metal-nitrogen-carbon (M-N-C) catalysts have exhibited encouraging oxygen reduction reaction (ORR) activity. Nevertheless, the insufficient long-term stability remains a widespread concern owing to the inevitable 2-electron byproducts, H2O2. Here, we construct Co-N-Cr cross-interfacial electron bridges (CIEBs) via the interfacial electronic coupling between Cr2O3 and Co-N-C, breaking the activity-stability trade-off. The partially occupied Cr 3d-orbitals of Co-N-Cr CIEBs induce the electron rearrangement of CoN4 sites, lowering the Co-OOH* antibonding orbital occupancy and accelerating the adsorption of intermediates. Consequently, the Co-N-Cr CIEBs suppress the two-electron ORR process and approach the apex of Sabatier volcano plot for four-electron pathway simultaneously. As a proof-of-concept, the Co-N-Cr CIEBs is synthesized by the molten salt template method, exhibiting dominant 4-electron selectively and extremely low H2O2 yield confirmed by Damjanovic kinetic analysis. The Co-N-Cr CIEBs demonstrates impressive bifunctional oxygen catalytic activity (▵E=0.70 V) and breakthrough durability including 100 % current retention after 10 h continuous operation and cycling performance over 1500 h for Zn-air battery. The hybrid interfacial configuration and the understanding of the electronic coupling mechanism reported here could shed new light on the design of superdurable M-N-C catalysts.

CD11b mediates hypertensive cardiac remodeling by regulating macrophage infiltration and polarization.

INTRODUCTION: Leukocyte infiltration is an early event during cardiac remodeling frequently leading to heart failure (HF). Integrins mediate leukocyte infiltration during inflammation. However, the importance of specific integrins in hypertensive cardiac remodeling is still unclear. OBJECTIVES: To elucidate the significance of CD11b in hypertensive cardiac remodeling. METHODS: Angiotensin (Ang II) or deoxycorticosterone acetate (DOCA)-salt was used to induce cardiac remodeling in mice of gene knockout (KO), bone marrow (BM) chimera, and the CD11b neutralizing antibody or agonist leukadherin-1 (LA1) treatment. RESULTS: Our microarray data showed that integrin subunits Itgam (CD11b) and Itgb2 (CD18) were the most highly upregulated in Ang II-infused hearts. CD11b expression and CD11b/CD18+ myelomonocytes were also time-dependently increased. KO or pharmacological blockade of CD11b greatly attenuated cardiac remodeling and macrophage infiltration and M1 polarization induced by Ang II or DOCA-salt. This protection was verified in wild-type mice transplanted with CD11b-deficient BM cells. Conversely, administration of CD11b agonist LA1 showed the opposite effects. Further, CD11b KO reduced Ang II-induced macrophage adhesion and M1 polarization, leading to reduction of cardiomyocyte enlargement and fibroblast differentiation in vitro. The numbers of CD14+CD11b+CD18+ monocytes and CD15+CD11b+CD18+ granulocytes were obviously higher in HF patients than in normal controls. CONCLUSION: Our data demonstrate an important role of CD11b+ myeloid cells in hypertensive cardiac remodeling, and suggest that HF may benefit from targeting CD11b.

Gankyrin inhibits ferroptosis through the p53/SLC7A11/GPX4 axis in triple-negative breast cancer cells.

Gankyrin is found in high levels in triple-negative breast cancer (TNBC) and has been established to form a complex with the E3 ubiquitin ligase MDM2 and p53, resulting in the degradation of p53 in hepatocarcinoma cells. Therefore, this study sought to determine whether gankyrin could inhibit ferroptosis through this mechanism in TNBC cells. The expression of gankyrin was investigated in relation to the prognosis of TNBC using bioinformatics. Co-immunoprecipitation and GST pull-down assays were then conducted to determine the presence of a gankyrin and MDM2 complex. RT-qPCR and immunoblotting were used to examine molecules related to ferroptosis, such as gankyrin, p53, MDM2, SLC7A11, and GPX4. Additionally, cell death was evaluated using flow cytometry detection of 7-AAD and a lactate dehydrogenase release assay, as well as lipid peroxide C11-BODIPY. Results showed that the expression of gankyrin is significantly higher in TNBC tissues and cell lines, and is associated with a poor prognosis for patients. Subsequent studies revealed that inhibiting gankyrin activity triggered ferroptosis in TNBC cells. Additionally, silencing gankyrin caused an increase in the expression of the p53 protein, without altering its mRNA expression. Co-immunoprecipitation and GST pull-down experiments indicated that gankyrin and MDM2 form a complex. In mouse embryonic fibroblasts lacking both MDM2 and p53, this gankyrin/MDM2 complex was observed to ubiquitinate p53, thus raising the expression of molecules inhibited by ferroptosis, such as SLC7A11 and GPX4. Furthermore, silencing gankyrin in TNBC cells disrupted the formation of the gankyrin/MDM2 complex, hindered the degradation of p53, increased SLC7A11 expression, impeded cysteine uptake, and decreased GPX4 production. Our findings suggest that TNBC cells are able to prevent cell ferroptosis through the gankyrin/p53/SLC7A11/GPX4 signaling pathway, indicating that gankyrin may be a useful biomarker for predicting TNBC prognosis or a potential therapeutic target.

Molecular targeted therapy and immunotherapy in advanced hepatocellular carcinoma: a systematic review and Bayesian network meta-analysis based on randomized controlled trials.

OBJECTIVE: The aim of this study was to compare and rank different targeted therapies or immunotherapies for advanced hepatocellular carcinoma based on efficacy. METHODS: A systematic search of the PubMed, EMBASE, and Cochrane Library databases was conducted. All systematic treatment regimens that reported comparisons with sorafenib were included in this analysis. The primary outcome measures were overall survival (OS) and progression-free survival (PFS), and other outcome measures included the objective response rate (ORR) and safety analysis according to reported treatment-related adverse events. RESULTS: A total of 29 RCTs involving 13376 patients were included in the analysis, including 10 single-agent therapies and 17 combination therapies. Compared with sorafenib, sintilimab plus IBI305 (HR: 0.57, 95% CI: 0.43-0.75), camrelizumab plus rivoceranib (HR: 0.62, 95% CI: 0.49-0.78), and atezolizumab plus bevacizumab (HR: 0.66, 95% CI: 0.52-0.83) ranked in the top three in terms of OS. CONCLUSIONS: PD-1/PD-L1 inhibitors combined with anti-vascular endothelial growth factor (anti-VEGF)-targeting drugs have shown better therapeutic effects in the systematic treatment of patients with advanced hepatocellular carcinoma, and the combination of targeted and immune therapy modes should be further developed.

CD1d-Dependent Natural Killer T Cells Mediate Hypertension and Vascular Injury Through Interleukin-17A.

Background Different T-lymphocyte subsets, including CD1d-dependent natural killer T (NKT) cells, play distinct roles in hypertension, highlighting the importance of identifying key immune cells for its treatment. This study aimed to determine the unknown effects of CD1d-dependent NKT cells on hypertension and vascular injury. Methods and Results Hypertension models were induced in male CD1d knockout (CD1dko), wild-type, and adoptive bone marrow transfer mice by angiotensin II (Ang II) or deoxycorticosterone acetate salt. Blood pressure was measured by the tail-cuff system and radiotelemetry. Vascular injury was assessed by histologic studies or aortic ring assay. Inflammation was detected by flow cytometry, quantitative real-time polymerase chain reaction, or ELISA. Results showed that Ang II infusion significantly reduced CD1d expression and NKT cell numbers in the aorta of mice. CD1dko mice exhibited worsened blood pressure elevation, vascular injury, and inflammatory response induced by Ang II or deoxycorticosterone acetate salt. However, these effects were markedly reversed in wild-type mice treated with NKT cell-specific activator. Adoptive transfer of CD1dko bone marrow cells to wild-type mice also significantly worsened Ang II-induced responses. Mechanistically, CD1dko increased Ang II-induced interleukin-6 production and activated signal transducer and activator of transcription 3 and orphan nuclear receptor γ, subsequently inducing interleukin-17A production. Neutralizing interleukin-17A partially reversed Ang II-induced hypertension and vascular injury in CD1dko mice. In addition, levels of NKT cells were lower in the blood of patients with hypertension (n=57) compared with normotensive individuals (n=87). Conclusions These findings reveal a previously unknown role for CD1d-dependent NKT cells in hypertension and vascular injury, indicating that NKT cell activation could be a promising therapeutic target for hypertension.

Single-Cell Transcriptome Analysis of Peripheral Neutrophils From Patients With Idiopathic Pulmonary Arterial Hypertension.

BACKGROUND: Idiopathic pulmonary hypertension (IPAH) is a rare and devastating disease often accompanied by persistent inflammation and immune responses. We aim to provide a reference atlas of neutrophils to facilitate a better understanding of cellular phenotypes and discovery of candidate genes. METHODS: Peripheral neutrophils from naive patients with IPAH and matched controls were profiled. Whole-exon sequencing was performed to exclude known genetic mutations before establishing single-cell RNA sequencing. Marker genes were validated by flow cytometry and histology in a separate validation cohort. RESULTS: Seurat clustering analysis revealed that the landscape of neutrophils encompassed 5 clusters, including 1 progenitor, 1 transition, and 3 functional clusters. The intercorrelated genes in patients with IPAH were mainly enriched in antigen processing presentation and natural killer cell mediated cytotoxicity. We identified and validated differentially upregulated genes, including MMP9 (matrix metallopeptidase 9), ISG15 (ISG15 ubiquitin-like modifier), and CXCL8 (C-X-C motif ligand 8). The positive proportions and fluorescence quantification of these genes were significantly increased in CD16+ neutrophils in patients with IPAH. The higher proportion of positive MMP9 neutrophils increased mortality risk after adjustment for age and sex. Patients with higher proportions of positive MMP9 neutrophils had worse survival, while the fraction of ISG15- or CXCL8-positive expression neutrophils failed to predict outcome. CONCLUSIONS: Our study yields a comprehensive dataset of the landscape of neutrophils in patients with IPAH. The predictive values of a neutrophil cluster characterized by higher MMP9 expression indicate a functional role for neutrophil-specific matrix metalloproteinases in the pathogenesis of pulmonary arterial hypertension.

Fractional flow reserve measured via left internal mammary artery after coronary artery bypass grafting: Two case reports.

BACKGROUND: The fractional flow reserve (FFR) has made the treatment of coronary heart disease more precise. However, there are few reports on the measurement of FFR via the left internal mammary artery (LIMA). Herein, we described the determination of further treatments by measuring FFR via the LIMA in 2 cases after coronary artery bypass grafting (CABG). CASE SUMMARY: Case 1 was a 66-year-old male who was admitted due to "chest tightness after CABG." The patient underwent CABG 7 years prior due to coronary heart disease. Coronary artery angiography showed complete occlusion of the left anterior descending artery (LAD), and subtotal occlusion of the third segment of the right coronary artery. On arterial angiography, there was 85% stenosis at the distal end of the anastomosis of the LIMA-LAD graft. FFR via LIMA was determined at 0.75. Thus, balloon dilation was performed in Case 1. FFR after balloon dilation was 0.94. Case 2 was a 60-year-old male who was admitted due to "chest tightness after CABG." The patient underwent CABG 6 years prior due to coronary heart disease. There was 60% segmental stenosis in the middle segment of LAD and 75% anastomotic stenosis. FFR measured via LIMA was 0.83 (negative); thus the intervention was not performed. Case 2 was given drug treatments. At the 3-mo follow-up, there was no recurrence of chest tightness or shortness of breath in both cases. They are currently under continual follow-up. CONCLUSION: We provided evidence that FFR measurement via grafted blood vessels, especially LIMA, after CABG is a good method to determine the intervention course.

Adipose Triglyceride Lipase Deficiency Aggravates Angiotensin II-Induced Atrial Fibrillation by Reducing Peroxisome Proliferator-Activated Receptor α Activation in Mice.

Atrial fibrillation (AF) is a main risk factor for cerebrovascular diseases but lacks precision therapy. Adipose triglyceride lipase (ATGL) is a key enzyme involved in the intracellular degradation of triacylglycerol and plays an important role in lipid and energy metabolism. However, the role of ATGL in the regulation of AF remains unclear. In this study, AF was induced by infusion of angiotensin II (Ang II, 2000 ng/kg/min) for 3 weeks in male ATGL knockout (KO) mice and age-matched C57BL/6 wild-type mice. The atrial volume was measured by echocardiography. Atrial fibrosis, inflammatory cells, and superoxide production were detected by histologic examinations. The results showed that ATGL expression was significantly downregulated in the atrial tissue of the Ang II-infused mice. Moreover, Ang II-induced increase in the inducibility and duration of AF, atrial dilation, fibrosis, inflammation, and oxidative stress in wild-type mice were markedly accelerated in ATGL KO mice; however, these effects were dramatically reversed in the ATGL KO mice administered with peroxisome proliferator-activated receptor (PPAR)-α agonist clofibric acid. Mechanistically, Ang II downregulated ATGL expression and inhibited PPAR-α activity, activated multiple signaling pathways (inhibiting kappa B kinase α/ß-nuclear factor-κB, nicotinamide adenine dinucleotide phosphate oxidase, and transforming growth factor-ß1/SMAD2/3) and reducing Kv1.5, Cx40, and Cx43 expression, thereby contributing to atrial structural and electrical remodeling and subsequent AF. In summary, our results indicate that ATGL KO enhances AF inducibility, possibly through inhibiting PPAR-α activation and suggest that activating ATGL might be a new therapeutic option for treating hypertensive AF.

Fe-N-C catalysts decorated with oxygen vacancies-rich CeOx to increase oxygen reduction performance for Zn-air batteries.

Platinum group metal (PGM)-free catalysts represented by nitrogen and iron co-doped carbon (Fe-N-C) catalysts are desirable and critical for metal-air batteries, but challenges still exist in performance and stability. Here, cerium oxides (CeOx) are incorporated into a two-dimensional Fe-N-C catalyst (FeNC-Ce-950) via a host-guest strategy. The Ce4+/Ce3+ redox system creates a large number of oxygen vacancies for rapid O2 adsorption to accelerate the kinetics of oxygen reduction reaction (ORR). Consequently, the as-synthesized FeNC-Ce-950 catalyst exhibits a half-wave potential (E1/2) of 0.921 V and negligible decay (<2 mV for ΔE1/2) after 5,000 accelerated durability cycles, significantly outperforming most of ORR catalysts reported in recent years and precious metal counterparts. When applied in a zinc-air battery, it demonstrates a peak power density of 175 mW cm-2 and a specific capacity of 757 mAh gZn-1. This study also provides a reference for the exploration of Fe-N-C catalysts decorated with variable valence metal oxides.

ATGL deficiency aggravates pressure overload-triggered myocardial hypertrophic remodeling associated with the proteasome-PTEN-mTOR-autophagy pathway.

Persistent myocardial hypertrophy frequently leads to heart failure (HF). Intramyocardial triacylglycerol (TAG) accumulation is closely related with cardiac remodeling and abnormal contractile function. Adipose triglyceride lipase (ATGL), a key enzyme in TAG metabolism, regulates cardiac function. However, its associated molecular pathways have not been fully defined. Here, cardiac hypertrophy and HF were induced in wild-type (WT) or ATGL knockout (KO) mice through transverse aortic constriction (TAC) for up to 4 weeks. TAC in WT mice significantly reduced cardiac function and autophagy while enhancing left ventricular hypertrophy, interstitial fibrosis, inflammatory response, superoxide generation, and cardiomyocyte apoptosis, accompanied with upregulation of the proteasome activity, reduction of PTEN level and activation of AKT-mTOR signaling, and these effects were further aggravated in ATGL KO mice. Interestingly, ATGL KO-mediated cardiac dysfunction and remodeling were markedly reversed by proteasome inhibitor (epoxomicin) or autophagic activator (rapamycin), but accelerated by PTEN inhibitor (VO-OHpic) or autophagy inhibitor 3-MA. Mechanistically, ATGL KO upregulated proteasome expression and activity, which in turn mediates PTEN degradation leading to activation of AKT-mTOR signaling and inhibition of autophagy, thereby enhancing hypertrophic remodeling and HF. In conclusion, ATGL KO contributes to TAC-induced cardiac dysfunction and adverse remodeling probably associated with the proteasome-PTEN-mTOR-autophagy pathway. Therefore, modulation of this pathway may have a therapeutic effect potential for hypertrophic heart disease. TAC-induced downregulation of ATGL results in increased proteasome (ß1i/ß2i/ß5i) activity, which in turn promotes degradation of PTEN and activation of AKT-mTOR signaling and then inhibits autophagy and ATP production, thereby leading to cardiac hypertrophic remodeling and dysfunction. Conversely, blocking proteasome activity or activating autophagy attenuates these effects.

Integrin CD11b Contributes to Hypertension and Vascular Dysfunction Through Mediating Macrophage Adhesion and Migration.

BACKGROUND: Leukocyte adhesion to endothelium is an early inflammatory response and is mainly controlled by the ß2-integrins. However, the role of integrin CD11b/CD18 in the pathogenesis of hypertension and vascular dysfunction is unclear. METHODS: Hypertension was established by angiotensin II (490 ng/kg·per min) or deoxycorticosterone acetate salt. Hypertensive responses were studied in CD11b-deficient (CD11b-/-) mice, bone marrow transplanted and wild-type (WT) mice that were administered anti-CD11b neutralizing antibody or agonist leukadherin-1. Blood pressure was monitored with tail-cuff method and radiotelemetry. Blood and vascular inflammatory cells were assessed by flow cytometry. Aortic remodeling and function were examined using histology and aortic ring analysis. Cell adhesion and migration were evaluated in vitro. The relationship between circulating CD11b+ immune cells and hypertension was analyzed in patients with hypertension. RESULTS: We found that CD11b and CD18 expression as well as the CD45+CD11b+CD18+ myeloid cells were highly increased in the aorta of angiotensin II-infused mice. Ablation or pharmacological inhibition of CD11b in mice significantly alleviated hypertension, aortic remodeling, superoxide generation, vascular dysfunction, and the infiltration of CD11b+ macrophages through reducing macrophage adhesion and migration. These effects were confirmed in WT mice reconstituted with CD11b-deficient bone marrow cells. Conversely, angiotensin II-induced hypertensive response was exacerbated by CD11b agonist leukadherin-1. Notably, circulating CD45+CD11b+CD18+ myeloid cells and the ligand levels in hypertensive patients were significantly higher than in normotensive controls. CONCLUSIONS: We demonstrated a critical significance of CD11b+ myeloid cells in hypertension and vascular dysfunction. Targeting CD11b may represent a novel therapeutic option for hypertension.

Comparison of the supraglottic airway device BlockBusterTM and laryngeal mask airway Supreme in anaesthetised, paralyzed adult patients: a multicenter randomized controlled trial.

BACKGROUND: This multicenter prospective, randomized controlled clinical trial compared the clinical performance of supraglottic airway device (SAD) BlockBusterTM and laryngeal mask airway (LMA) Supreme for airway maintenance in anesthetized, paralyzed adult patients. METHODS: A total of 651 adult patients scheduled for elective surgery in 13 hospitals were randomly allocated into BlockBuster group (n = 351) or Supreme group (n = 300). The primary outcome was oropharyngeal leak pressure (OLP). Duration and ease of insertion, fiberscopic view of positioning, airway manipulations, and complications were also assessed. RESULTS: The OLP was significantly higher in BlockBuster group compared with Supreme group (29.9 ± 4.2 cmH2O vs 27.4 ± 4.3 cmH2O, p < 0.001). Success rate of insertion at the first attempt (90.2% vs 85.1%, p = 0.027), rate of optimal fiberscopic view (p = 0.002) and satisfactory positioning of SAD (p < 0.001) were significantly increased in BlockBuster group. CONCLUSIONS: Both SAD BlockBusterTM and LMA Supreme are safe, effective, and easy-to-use devices for airway maintenance in anesthetized, paralyzed adult patients, but the SAD BlockBusterTM is superior to LMA Supreme in terms of OLP, success rate at the first attempt, and fiber-optic view of positioning. TRIAL REGISTRATION: The trial is registered at www.chictr.org.cn (ChiCTR-ONC-16009105).

Regulation of Rhesus glycoprotein-related genes in large-scale loach Paramisgurnus dabryanus during ammonia loading.

Waterborne ammonia is one of the crucial issues that limited production and animal health in aquaculture. Ammonia-tolerant varieties are highly desired in intensive fish farming. Screening for the key regulatory genes of ammonia tolerance is essential for variety breeding. According to the previous hypothesis, Rh glycoproteins play an important role in ammonia excretion in teleosts. However, the ammonia defensive mechanisms are not well described at present for large-scale loach (Paramisgurnus dabryanus), a typical air-breathing and commercially important fish in East Asia. Here we show that the transcription of Rh glycoprotein-related genes was significantly affected by ammonia exposure in this species. Probit analysis showed that 96 h-LC50 of NH4Cl at 23 â„ƒ and pH 7.2 was 92.64 mmol/L. A significant increase of Rhcg expression in gills was observed after 48 h of 60 mmol/L and 36 h of 80 mmol/L NH4Cl exposure, suggesting that Rhcg present on the apical side of the branchial epithelium facilitates NH3 excretion out of gills. A high concentration of acute ammonia exposure induced elevated Rhbg transcript in the gills of large-scale loaches, while a slight change in Rhbg expression was observed in response to lower ammonia, suggesting that transcriptions of Rhbg genes are activated by a considerably high level of ambient ammonia to eliminate excessive endogenous nitrogen. The Rhag mRNA level in gills of large-scale loaches increased markedly with the prolonging of exposure time from 0 to 36 h of ammonia loading, suggesting Rhag localized in gills may be primarily associated with ammonia handling. During 7-21 days of ammonia exposure, the expression of most Rh glycoproteins-related genes in the gills decreased, indicating that the functional role of Rh glycoproteins is not primarily associated with ammonia defense over a long period (more than 7 days). Although a significant transcript of Rhbg was found in the skin of a large-scale loach, the lack of Rhcg and down-regulation of Rhag may indicate that the skin is not an essential location of ammonia excretion, at least when submerged to high levels of ammonia in the environment. In conclusion, Rh glycoproteins localized in gills as ammonia transporters play a momentous role in ammonia detoxification in this species during acute ammonia loading. However, it does not show a positive function during long-term ammonia exposure. Furthermore, the physiological function of Rh glycoproteins localized in the skin is still unclear and deserves further study.

CXCL1-CXCR2 signalling mediates hypertensive retinopathy by inducing macrophage infiltration.

Inflammation plays an important role in hypertensive retinal vascular injury and subsequent retinopathy. Monocyte chemotaxis via CXCL1-CXCR2 binding has been implicated in various cardiovascular diseases, but the function of CXCL1-CXCR2 signalling involved in retinopathy, which was investigated as angiotensin II (Ang II)-induced retinopathy, is unclear. In our study, we established a hypertensive retinopathy (HR) model by Ang II infusion (3000 ng/min/kg) for 3 weeks. To determine the involvement of CXCR2 signalling, we used CXCR2 knockout (KO) mice or C57BL/6J wild-type (WT) mice as experimental subjects. The mice were treated with a CXCL1 neutralizing antibody or SB225002 (the specific CXCR2 inhibitor). Our results showed that after Ang II treatment, the mRNA levels of CXCL1 and CXCR2 and the number of CXCR2+ inflammatory cells were significantly elevated. Conversely, unlike in the IgG control group, the CXCL1 neutralizing antibody greatly reduced the increase in central retinal thickness induced by Ang II infusion, arteriolar remodelling, superoxide production, and retinal dysfunction in WT mice. Furthermore, Ang II infusion induced arteriolar remodelling, infiltration of Iba1+ macrophages, the production of oxidative stress, and retinal dysfunction, but the symptoms were ameliorated in CXCR2 KO mice and SB225002-treated mice. These protective effects were related to the reduction in the number of CXCR2+ immune cells, particularly macrophages, and the decrease in proinflammatory cytokine (IL-1ß, IL-6, TNF-ɑ, and MCP-1) expression in Ang II-treated retinas. Notably, serum CXCL1 levels and the number of CXCR2+ monocytes/neutrophils were higher in HR patients than in healthy controls. In conclusion, this study provides new evidence that the CXCL1-CXCR2 axis plays a vital role in the pathogenesis of hypertensive retinopathy, and selective blockade of CXCL1-CXCR2 activation may be a potential treatment for HR.

Time Series Transcriptomic Analysis by RNA Sequencing Reveals a Key Role of PI3K in Sepsis-Induced Myocardial Injury in Mice.

Septic cardiomyopathy is the main complication and cause of death of severe sepsis with limited therapeutic strategy. However, the molecular mechanism of sepsis-induced cardiac injury remains unclear. The present study was designed to investigate differentially expressed genes (DEGs) involved in the pathogenesis of septic cardiomyopathy induced by cecal ligation and puncture (CLP) in mice. Male C57BL/6J mice (8-10 weeks old) were subjected to CLP with 21-gauge needles for 24, 48, and 72 h. Myocardial function was assessed by echocardiography. The pathological changes of the heart were evaluated by hematoxylin and eosin as well as immunohistochemical staining. Time series RNA sequencing was utilized to investigate the gene expression profiles. CLP surgery resulted in a significant decrease of animal survival rate and left ventricle contractile function, and an increase in cardiac dilation and infiltration of proinflammatory cells including Mac-2+ macrophages in a time-dependent manner. RNA sequencing identified 5,607 DEGs in septic myocardium at 24, 48, and 72 h after CLP operation. Moreover, gene ontology analysis revealed that these DEGs were mainly associated with the biological processes, including cell adhesion, immune system process, inflammatory response, and positive regulation of cell migration. KEGG pathway enrichment analysis indicated that Staphylococcus aureus infection, osteoclast differentiation, leishmaniasis, and ECM-receptor interaction were significantly altered in septic hearts. Notably, Pik3r1 and Pik3r5 were localized in the center of the gene co-expression network, and were markedly upregulated in CLP-induced septic myocardium. Further, blocking PI3Kγ by the specific inhibitor CZC24832 significantly protected against sepsis-induced cardiac impairment. The present study uncovers the gene expression signatures of CLP-induced myocardial injury and sheds light on the role of Pik3r5 in septic cardiomyopathy.

Blockage of Fibronectin 1 Ameliorates Myocardial Ischemia/Reperfusion Injury in Association with Activation of AMP-LKB1-AMPK Signaling Pathway.

Myocardial ischemia/reperfusion injury (I/RI) is closely associated with energy substrate metabolism. Fibronectin 1 (Fn1) was markedly elevated in the heart of I/R pigs and ischemic patients, but its role in myocardial I/RI is controversial and the precise mechanism involved remains elusive. Herein, we tested whether blockage of Fn1 with its inhibitor (fibronectin tetrapeptide, RGDS) would alleviate myocardial I/RI. Wild-type (WT) mice were administered with RGDS once 3 h before I/R operation and once at 24 or 48 h postreperfusion, and sacrificed at 24 or 72 h post-I/R, respectively. Cardiac function was evaluated by echocardiography. Myocardial infarction size, apoptosis, fibrosis, and inflammation were examined via histological staining. Uptake of glucose and fatty acids were detected by positron emission tomography (PET) and computer tomography (CT) with [18F]-2-fluoro-2-deoxy-D-glucose (FDG) and [18F]-fluoro-6-thia-heptadecanoic acid (FTHA), respectively. Our results showed that administration of RGDS to mice remarkably limited the I/R-induced myocardial infarct size, myocyte apoptosis, inflammation, oxidative stress, and fibrosis and improved cardiac contractile dysfunction. These protective effects were associated with upregulation of the AMP/ATP ratio and the activation of LKB1-AMPK signaling, which subsequently increased AS160-GLUT4-mediated glucose and fatty acid uptake, improved mitochondrial dynamic imbalance, and inactivated TGF-ß and NF-κB signals in the I/R heart. In conclusion, the current study identified that blocking Fn1 protects against myocardial I/RI likely through activating the LKB1-AMPK-dependent signals and highlights that inhibition of Fn1 may be a novel therapeutic option for treating ischemic heart diseases.

Angiotensin II Induces Cardiac Edema and Hypertrophic Remodeling through Lymphatic-Dependent Mechanisms.

Cardiac lymphatic vessel growth (lymphangiogenesis) and integrity play an essential role in maintaining tissue fluid balance. Inhibition of lymphatic lymphangiogenesis is involved in cardiac edema and cardiac remodeling after ischemic injury or pressure overload. However, whether lymphatic vessel integrity is disrupted during angiotensin II- (Ang II-) induced cardiac remodeling remains to be investigated. In this study, cardiac remodeling models were established by Ang II (1000 ng/kg/min) in VEGFR-3 knockdown (Lyve-1Cre VEGFR-3f/-) and wild-type (VEGFR-3f/f) littermates. Our results indicated that Ang II infusion not only induced cardiac lymphangiogenesis and upregulation of VEGF-C and VEGFR-3 expression in the time-dependent manner but also enhanced proteasome activity, MKP5 and VE-cadherin degradation, p38 MAPK activation, and lymphatic vessel hyperpermeability. Moreover, VEGFR-3 knockdown significantly inhibited cardiac lymphangiogenesis in mice, resulting in exacerbation of tissue edema, hypertrophy, fibrosis superoxide production, inflammation, and heart failure (HF). Conversely, administration of epoxomicin (a selective proteasome inhibitor) markedly mitigated Ang II-induced cardiac edema, remodeling, and dysfunction; upregulated MKP5 and VE-cadherin expression; inactivated p38 MAPK; and reduced lymphatic vessel hyperpermeability in WT mice, indicating that inhibition of proteasome activity is required to maintain lymphatic endothelial cell (LEC) integrity. Our results show that both cardiac lymphangiogenesis and lymphatic barrier hyperpermeability are implicated in Ang II-induced adaptive hypertrophic remodeling and dysfunction. Proteasome-mediated hyperpermeability of LEC junctions plays a predominant role in the development of cardiac remodeling. Selective stimulation of lymphangiogenesis or inhibition of proteasome activity may be a potential therapeutic option for treating hypertension-induced cardiac remodeling.

MicroRNA-451a attenuates angiotensin II–induced cardiac fibrosis and inflammation by directly targeting T-box1

Hypertension or angiotensin II (Ang II) induces cardiac inflammation and fibrosis, thus contributing to cardiac remodeling. MicroRNAs (miRNAs) are considered crucial regulators of cardiac homeostasis and remodeling in response to various types of stress. It has been reported that miR-451a is involved in regulating ischemic heart injury. However, its role in Ang II-induced cardiac fibrosis remains unknown. Cardiac remodeling was induced in mice by infusion of low-dose Ang II (490 ng/kg/min) with a minipump for 2 weeks. Echocardiography and histological examinations were performed to evaluate cardiac function and pathological changes. We observed that miR-451a expression was the most significantly downregulated in the hearts of Ang II-infused mice and in both primary cardiac myocytes and fibroblasts. Overexpression of miR-451a in mice significantly attenuated Ang II–induced cardiac fibrosis and inflammation. Conversely, knockdown of miR-451a in mice aggravated this effect. Bioinformatics analysis and a luciferase reporter assay revealed that TBX1 was a direct target of miR-451a. Mechanistically, miR-451a directly targeted TBX1 expression, which inhibited TGF-β1 production in both cardiac myocytes and fibroblasts, inactivating of TGF-β1/SMAD2/3 signaling, inhibiting myofibroblast differentiation and proinflammatory cytokine expression, and leading to attenuation of cardiac fibrosis and inflammation. In conclusion, these results indicate that miR-451a acts as a novel regulator of Ang II–induced cardiac fibrosis and inflammation by directly targeting TBX1, and may be a promising therapeutic target for treating hypertensive cardiac diseases. (AU)