MicroRNA let-7a mediates posttranscriptional inhibition of Nr4A1 and exacerbates cardiac allograft rejection.

BACKGROUND: Acute allograft rejection remains a major obstacle after heart transplantation, and CD4+ T cells play a crucial role in allograft rejection. Upregulation of Nr4A1 could regulate CD4+ T-cell function and alleviate allograft rejection. However, the regulatory mechanism of Nr4A1 in allograft rejection remains elusive. METHODS: BALB/c mouse hearts were transplanted into WT C57BL/6 mice, and dynamic detection of the changes in Nr4A1 expression revealed that Nr4A1 was regulated posttranscriptionally after heart transplantation. Potential upstream miRNAs of Nr4A1 were screened, and the transfection of cells with these miRNA mimics/inhibitors and dual-luciferase reporter experiments were performed to clarify the regulatory mechanism of miRNAs on Nr4A1 expression. The miRNA agomiR/antagomiR was applied in vivo to validate the role of the corresponding miRNA in heart transplantation. Finally, Nr4A1 knockout mice and an adoptive T-cell cotransfer model were used to confirm the specific effects of miRNA. RESULTS: The expression of Nr4A1 protein (rather than mRNA) exhibited a trend of initially increasing and then decreasing rapidly, and this phenomenon could not be reversed by lysosomal or proteasomal inhibitors. The miRNA let-7a directly binds to the Nr4A1 3'UTR and posttranscriptionally regulates Nr4A1 expression. The let-7a antagomiR prolonged allograft survival and regulated CD4+ T-cell function by upregulating Nr4A1 protein expression in CD4+ T cells. CONCLUSIONS: This study confirmed that let-7a is a potential target for interfering with Nr4A1 expression in CD4+ T cells and preventing the pathological progression of cardiac allograft rejection.

Nomogram and Risk Calculator for Postoperative Tracheostomy after Heart Valve Surgery.

Postoperative tracheostomy (POT) is an important indicator of critical illness, associated with poorer prognoses and increased medical burdens. However, studies on POTs after heart valve surgery (HVS) have not been reported. The objectives of this study were first to identify the risk factors and develop a risk prediction model for POTs after HVS, and second to clarify the relationship between POTs and clinical outcomes. Consecutive adults undergoing HVS from January 2016 to December 2019 in a single cardiovascular center were enrolled, and a POT was performed in 1.8% of the included patients (68/3853). Compared to patients without POTs, the patients with POTs had higher rates of readmission to the ICU and in-hospital mortality, as well as longer ICU and hospital stays. Five factors were identified to be significantly associated with POTs after HVS by our multivariate analysis, including age, diabetes mellitus, pulmonary edema, intraoperative transfusion of red blood cells, and surgical types. A nomogram and a risk calculator were constructed based on the five factors, showing excellent discrimination, calibration, and clinical utility. Three risk intervals were defined as low-, medium-, and high-risk groups according to the nomogram and clinical practice. The findings of this study may be helpful for early risk assessment and perioperative management.

The Roles and Mechanisms of TRAT1 in the Progression of Non-Small Cell Lung Cancer.

OBJECTIVE: T cell receptor-associated transmembrane adaptor 1 (TRAT1) is one of the hub genes regulating T cell receptors (TCRs). Herein, the roles of TRAT1 in the prognosis and immune microenvironment of non-small cell lung cancer (NSCLC) were investigated. METHODS: The expression and prognosis values of TRAT1 in NSCLC, and the relationship between TRAT1 expression levels and cancer immune cell infiltration was identified via the TIMER, UALCAN, TISIDB, and other databases. The mechanism of TRAT1 in NSCLC was analyzed using gene set enrichment analysis (GSEA). RESULTS: The expression level of TRAT1 was decreased in NSCLC tissues. Low TRAT1 expression was associated with shorter overall survival of patients with NSCLC and was related to gender, smoking, and tumor grade. TRAT1 was involved in regulating immune response, TCR signaling pathway, PI3K/AKT, and other processes. TRAT1 expression levels were positively correlated with immune cell infiltration in NSCLC. CONCLUSION: Down-regulation of TRAT1 expression was associated with an unfavorable prognosis and immune infiltration of NSCLC.

Nomogram and risk calculator for severe hypoxemia after heart valve surgery.

Background: Hypoxemia is a very common issue in patients undergoing heart valve surgery (HVS), related to poor clinical outcomes. However, studies on severe hypoxemia (SH) after HVS have not been reported. The aims of this study were to identify predictors for SH in patients undergoing HVS and to develop and validate a risk prediction model. Methods: Patients undergoing HVS between 2016 and 2019 in a cardiovascular center were enrolled and were assigned to training and validation sets by a 7:3 ratio. Based on whether patients developed SH, they were divided into two groups. By univariate and multivariate analysis, predictors for SH were identified. Based on the predictors and logistic rule, a nomogram and a risk calculator were generated. The model was evaluated using calibration, discrimination and clinical utility. Results: The incidence rates of SH, moderate hypoxemia and mild hypoxemia were respectively 2.4, 23.9, and 58.2%. By multivariate analysis, seven independent risk factors for SH after HVS were identified, including body mass index, chronic obstructive pulmonary disease, renal insufficiency, white blood cell count, serum globulin, cardiopulmonary bypass time, and surgical types. The logistic model demonstrated satisfactory discrimination, calibration and clinical utility in both the training and validation sets. A nomogram and a risk calculator based on the logistic model were generated for easy application. Risk stratification was performed and three risk intervals were defined according to the nomogram and clinical practice. In addition, compared to patients without SH, patients with SH had significantly poorer clinical outcomes. Conclusions: Postoperative hypoxemia was prevalent after HVS, related to poor clinical outcomes. A logistic model including seven independent predictors for SH after HVS were established and validated, which demonstrated satisfactory discrimination, calibration and clinical utility. The results of this study may provide help to individualized risk assessment, early prevention and perioperative management.

Incidence, Risk Factors, and Outcomes of Severe Hypoxemia After Cardiac Surgery.

Background: Hypoxemia is common in patients undergoing cardiac surgery, however, few studies about severe hypoxemia (SH) after cardiac surgery exist. The objectives of this study were to clarify the incidence, risk factors, and outcomes of SH after cardiac surgery. Methods: Patients undergoing cardiac surgery from 2016 to 2019 in a single center were enrolled and were divided into two groups based on whether postoperative SH developed. Independent risk factors for SH were identified by univariate and multivariate analysis. Model selection statistics were applied to help determine the most parsimonious final model. Results: Severe hypoxemia developed in 222 of the 5,323 included patients (4.2%), was associated with poorer clinical outcomes. Six independent risk factors for SH after cardiac surgery were identified by multivariate analysis, such as surgical types, white blood cell (WBC) count, body mass index (BMI), serum albumin, cardiopulmonary bypass (CPB) time, and intraoperative transfusion of red blood cells (RBCs). After comprehensively considering the discrimination, calibration, and simplicity, the most appropriate and parsimonious model was finally established using four predictors, such as WBC count, BMI, CPB time, and intraoperative transfusion of RBCs. A nomogram and a web-based risk calculator based on the final model were constructed to facilitate clinical practice. Patients were stratified into three risk groups based on the nomogram and clinical practice. Conclusion: Severe hypoxemia was common after cardiac surgery and was associated with poorer clinical outcomes. A parsimonious final model with good discrimination, calibration, and clinical utility was constructed, which may be helpful for personalized risk assessment and targeted intervention.

Clinical Roles of Risk Model Based on Differentially Expressed Genes in Mesenchymal Stem Cells in Prognosis and Immunity of Non-small Cell Lung Cancer.

The tumor microenvironment (TME) plays an important regulatory role in the progression of non-small cell lung cancer (NSCLC). Mesenchymal stem cells (MSCs) in the TME might contribute to the occurrence and development of cancer. This study evaluates the role of differentially expressed genes (DEGs) of MSCs and the development of NSCLC and develops a prognostic risk model to assess the therapeutic responses. The DEGs in MSCs from lung tissues and from normal tissues were analyzed using GEO2R. The functions and mechanisms of the DEGs were analyzed using the Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Additionally, the Cancer Genome Atlas (TCGA) database was used to determine the expression levels of the DEGs of MSCs in the NSCLC tissues. The prognostic factors of NSCLC related to MSCs were screened by survival analysis, meta-analysis, Cox regression analysis, and a prognostic risk model and nomogram was developed. The signaling mechanisms and immune roles that risk model participate in NSCLC development were determined via Gene Set Enrichment Analysis and CIBERSORT analysis. Compared to the normal tissues, 161 DEGs were identified in the MSCs of the lung tissues. These DEGs were associated with mechanisms, such as DNA replication, nuclear division, and homologous recombination. The overexpression of DDIT4, IL6, ITGA11, MME, MSX2, POSTN, and TRPA1 were associated with dismal prognosis of NSCLC patients. A high-risk score based on the prognostic risk model indicated the dismal prognosis of NSCLC patients. The nomogram showed that the age, clinical stage, and risk score affected the prognosis of NSCLC patients. Further, the high-risk model was associated with signaling mechanisms, such as the ECM-receptor interaction pathways, cytokine-cytokine receptor interaction, and MAPK pathways, involved in the progression of NSCLC and was also related to the components of the immune system, such as macrophages M0, T follicular helper cells, regulatory T cells. Therefore, the risk model and nomogram that was constructed on the basis of MSC-related factors such as POSTN, TRPA1, and DDIT4 could facilitate the discovery of target molecules that participate in the progression of NSCLC, which might also serve as new candidate markers for evaluating the prognosis of NSCLC patients.

Cytosporone B (Csn-B), an NR4A1 agonist, attenuates acute cardiac allograft rejection by inducing differential apoptosis of CD4+T cells.

CD4+T cell-mediated acute rejection remains a major factor that affects the early survival of transplanted organs post-transplantation. Here, we reveal that nuclear receptor subfamily 4 Group A member 1 (Nr4A1) was upregulated during cardiac allograft rejection and that the increased Nr4A1 was primarily localized in intragraft-infiltrating CD4+T cells. Nr4A1 acts as a transcription factor with an important role in CD4+T cell apoptosis, differentiation and T cell dysfunction, which indicates that Nr4A1 may play a critical role in transplant rejection. Cytosporone B (Csn-B) is a naturally occurring agonist of Nr4A1, and the role of Csn-B in the physiological process of cardiac rejection is poorly defined. This study constructed an acute rejection model of abdominal heterotopic cardiac transplantation in mice and investigated whether Csn-B could attenuate acute transplant rejection by modulating the CD4+T lymphocyte response. The results showed that Csn-B prolonged murine cardiac allograft survival and reduced inflammation in allografts. Subsequently, it was confirmed that Csn-B functions by inducing non-Treg apoptosis and promoting Treg cell differentiation. Finally, we also confirmed that Csn-B attenuates acute rejection by directly targeting Nr4A1 in CD4+T cells. Our data suggest that Csn-B is a promising novel therapeutic approach for acute cardiac allograft rejection.

Plasma extracellular vesicle delivery of miR-210-3p by targeting ATG7 to promote sepsis-induced acute lung injury by regulating autophagy and activating inflammation.

Extracellular vesicles (EVs) can be used for intercellular communication by facilitating the transfer of miRNAs from one cell to a recipient cell. MicroRNA (miR)-210-3p is released into the blood during sepsis, inducing cytokine production and promoting leukocyte migration. Thus, the current study aimed to elucidate the role of plasma EVs in delivering miR-210-3p in sepsis-induced acute lung injury (ALI). Plasma EVs were isolated from septic patients, after which the expression of various inflammatory factors was measured using enzyme-linked immunosorbent assay. Cell viability and apoptosis were measured via cell counting kit-8 and flow cytometry. Transendothelial resistance and fluorescein isothiocyanate fluorescence were used to measure endothelial cell permeability. Matrigel was used to examine the tubulogenesis of endothelial cells. The targeting relationship between miR-210-3p and ATG7 was assessed by dual-luciferase reporter assays. The expression of ATG7 and autophagy-related genes was determined to examine autophagic activation. A sepsis mouse model was established by cecal ligation and puncture (CLP)-induced surgery. The level of miR-210-3p was highly enriched in septic EVs. MiR-210-3p enhanced THP-1 macrophage inflammation, BEAS-2B cell apoptosis, and HLMVEC permeability while inhibiting angiogenesis and cellular activity. MiR-210-3p overexpression reduced ATG7 and LC3II/LC3I expression and increased P62 expression. Improvements in vascular density and autophagosome formation, increased ATG7 expression, and changes in the ratio of LC3II/LC3I were detected, as well as reduced P62 expression, in adenovirus-anti-miR-210-3p treated mice after CLP injury. Taken together, the key findings of the current study demonstrate that plasma EVs carrying miR-210-3p target ATG7 to regulate autophagy and inflammatory activation in a sepsis-induced ALI model.

PKM2 Activator TEPP-46 Attenuates Thoracic Aortic Aneurysm and Dissection by Inhibiting NLRP3 Inflammasome-Mediated IL-1ß Secretion.

BACKGROUND: The development of thoracic aortic aneurysm and dissection (TAAD) is mediated by inflammasome activation, which exacerbates the secretion of pro-inflammatory cytokines, chemokines, matrix metalloproteinases (MMPs), and reactive oxygen species (ROS). The glycolytic enzyme pyruvate kinase M2 (PKM2) has shown a protective role against various disorders with an inflammatory basis, such as sepsis, tumorigenesis, and diabetic nephropathy. However, its potential role in TAAD has not been investigated so far. APPROACH AND RESULTS: We analyzed aortic tissues from TAAD patients and the ß-aminopropionitrile fumarate (BAPN)-induced mouse model of TAAD and observed elevated levels of PKM2 in the aortic lesions of both. Treatment with the PKM2 activator TEPP-46 markedly attenuated the progression of TAAD in the mouse model as demonstrated by decreased morbidity and luminal diameter of the aorta. In addition, the thoracic aortas of the BAPN-induced mice showed reduced monocytes and macrophages infiltration and lower levels of IL-1ß, MMPs, and ROS when treated with TEPP-46. Furthermore, TEPP-46 treatment also suppressed the activation of the NOD-like receptor (NLR) family and pyrin domain-containing protein 3 (NLRP3) inflammasome by downregulating p-STAT3 and HIF1-α. CONCLUSION: Pyruvate kinase M2 plays a protective role in TAAD development, and its activation is a promising therapeutic strategy against the progression of TAAD.

Nlrp3 Inflammasome Inhibitor MCC950 Ameliorates Obliterative Bronchiolitis by Inhibiting Th1/Th17 Response and Promoting Treg Response After Orthotopic Tracheal Transplantation in Mice.

BACKGROUND: Obliterative bronchiolitis (OB) remains the major complication limiting long-term survival of patients after lung transplantation. We aimed to explore the effects of the selective NACHT, LRR, and PYD domains-containing protein 3 (Nlrp3) inflammasome inhibitor MCC950 on the pathogenesis of OB. METHODS: Mouse orthotopic tracheal transplants were performed to mimic OB. MCC950 (50 mg/kg) or saline was intraperitoneally injected daily. The luminal occlusion rate and collagen deposition were evaluated by hematoxylin and eosin and Masson's trichrome staining, respectively. Infiltration of CD4+, CD8+ T cells, and neutrophils was detected with immunohistochemical staining. The frequencies of T helper 1 cell (Th1), T helper 17 cell (Th17), and regulatory T cells (Treg) were measured by flow cytometry. Cytokine levels were measured by ELISA kits. RESULTS: MCC950 treatment significantly inhibited Nlrp3 inflammasome activation after allogeneic tracheal transplant and markedly decreased the luminal occlusion rate and collagen deposition in the allograft. The numbers of infiltrating CD4+, CD8+ T cells, and neutrophils in the allograft were also significantly reduced by MCC950 treatment. MCC950 dramatically decreased the frequencies of Th1/Th17 cells and the levels of interferon gamma/interleukin (IL)-17A and increased the Treg cell frequencies and IL-10 level; however, these effects were abolished by the addition of IL-1ß and IL-18 both in vitro and in vivo. OB was also rescued by the addition of IL-1ß and/or IL-18. CONCLUSIONS: Blocking Nlrp3 inflammasome activation with MCC950 ameliorates OB lesions. The mechanistic analysis showed that MCC950 regulated the balance of Th1/Th17 and Treg cells and that this process is partially mediated by inhibition of IL-1ß and IL-18. Therefore, targeting the Nlrp3 inflammasome is a promising strategy for controlling OB after lung transplantation.

Trametinib alleviates lipopolysaccharide-induced acute lung injury by inhibiting the MEK-ERK-Egr-1 pathway.

Acute lung injury (ALI) is a devastating clinical disorder with a high mortality rate and for which there is no effective treatment. The main characteristic of ALI is uncontrolled inflammation, and macrophages play a critical role in the development of this disorder. Trametinib, an inhibitor of MAPK/ERK kinase (MEK) activity that possesses anti-inflammatory properties, has been approved for clinical use. Herein, the influence of trametinib and its underlying mechanism were investigated using a lipopolysaccharide (LPS)-induced murine ALI model. We found that trametinib treatment prevented the LPS-facilitated expression of proinflammatory mediators in macrophages, and this anti-inflammatory action was closely correlated with suppression of the MEK-ERK-early growth response (Egr)-1 pathway. Furthermore, trametinib treatment alleviated LPS-induced ALI in mice, and attenuated edema, proinflammatory mediator production, and neutrophil infiltration. Trametinib pretreatment also attenuated the MEK-ERK-Egr-1 pathway in lung tissues. In conclusion, these data demonstrate that trametinib pretreatment suppresses inflammation in LPS-activated macrophages in vitro and protects against murine ALI established by LPS administration in vivo through inhibition of the MEK-ERK-Egr-1 pathway. Therefore, trametinib might have therapeutic potential for ALI.

Inhibition of S-adenosyl-L-homocysteine hydrolase alleviates alloimmune response by down-regulating CD4+ T-cell activation in a mouse heart transplantation model.

BACKGROUND: Transmethylation reactions play an important role on lymphocyte activation and function. S-adenosyl-L-homocysteine hydrolase (SAHH) inhibitors prevent the feedback of transmethylation reactions by S-adenosyl-L-homocysteine (SAH) accumulation, a competitive antagonist of S-adenosylmethionine (SAM)-dependent methyltransferases. However, the role of SAH in solid organ transplantation is currently unclear. METHODS: A murine model of cardiac transplantation (BALB/C to C57B/6) was established to assess allograft survival, histology, and T cell infiltration. The reversible SAHH inhibitor, DZ2002, and irreversible SAHH inhibitor, adenosine dialdehyde (AdOx), were used to assess their immunosuppressive effects in murine cardiac transplantation, compared with mice with DMSO. RESULTS: Both SAHH inhibitors prolonged the survival of cardiac allografts and alleviated alloimmune response. Notably, AdOx and DZ2002 both eliminated frequencies of Th1 and Th17 in CD4+ T cells in cardiac transplantation, and reduced the frequency of active CD4+ T cell (CD44+ CD62L-). The irreversible SAHH inhibitor facilitated the differentiation of regulatory T cells (Tregs) and increased Bim expression. Furthermore, both SAHH inhibitors alleviated infiltration of CD4+ T cells in cardiac allografts. CONCLUSIONS: The SAHH inhibitors (AdOx and DZ2002) alleviates allograft rejection in cardiac transplantation by inhibition of CD4+ T alloimmune response. SAHH inhibitors, especially DZ2002, is a promising complementary therapeutic agent in organ transplantation.

TROVE2 strengthens the anti-inflammatory effect via macrophage polarization by estrogen induction in abdominal aortic aneurysm.

Abdominal Aortic Aneurysm (AAA) is a severe cardiovascular disease, with high mortality rate after acute rupture of blood vessels. However, the underlying pathogenesis of different morbidity between men and women remains unclear. In the present study, we first selected four datasets including 68 AAA and 32 control samples from published data on GEO database, and analyzed them by data mining. The integrative analysis found a total of 368 differentially expressed genes in E2-related AAA. Next, regulatory mechanism networks among these target genes were predicted, and four genes were identified as key nodes in the network, which play a major role in the immune system. We focused on the role of monocytes/macrophages in the development of cardiovascular diseases to further explore the role of estrogen in the polarization of monocytes/macrophage, the mRNA level of the four genes was validated by RT-PCR in RAW264.7 cells treated with ß-estradiol (E2), diarylpropionitrile (DPN), 1,3,5-Tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole (PPT), fulvestrant or vehicle. The results showed that the mRNA level and protein level of TROVE2 was significantly increased in estrogen or estrogen receptor agonist-treated groups. Moreover, estrogen affected the transformation of macrophages to M2 phenotype by detecting M1- and M2-related indicator genes at the mRNA level. Flow cytometry demonstrated that the TROVE2 deficiency led to a notable decrease in the level of M2 phenotype marker protein CD206. In conclusion, our results suggest that E2 can promote the expression of TROVE2, which is closely related to the M2-phenotype transformation of macrophages.

Challenges and countermeasures of thoracic surgery in the epidemic of novel coronavirus pneumonia / 中国胸心血管外科临床杂志

@#Since December 2019, a novel coronavirus (2019-nCoV, SARS-CoV-2) pneumonia (COVID-19) outbreak has occurred in Wuhan, Hubei Province, and the epidemic situation has continued to spread. Such cases have also been found in other parts of the country. The spread of the novel coronavirus pneumonia epidemic has brought great challenges to the clinical practice of thoracic surgery. Outpatient clinics need to strengthen the differential diagnosis of ground glass opacity and pulmonary plaque shadows. During the epidemic, surgical indications are strictly controlled, and selective surgery is postponed. Patients planning to undergo a limited period of surgery should be quarantined for 2 weeks and have a nucleic acid test when necessary before surgery. For patients who are planning to undergo emergency surgery, nucleic acid testing should be carried out before surgery, and three-level protection should be performed during surgery. Patients who are planning to undergo emergency surgery in the epidemic area should be confirmed with or without novel coronavirus pneumonia before operation, and perform nucleic acid test if necessary. Surgical disinfection and isolation measures should be strictly carried out. Among postoperative patients, cases with new coronavirus infection were actively investigated. For the rescue of patients with novel coronavirus infection, attention needs to be paid to prevention and treatment and related complications, including mechanical ventilation-related pneumothorax or mediastinal emphysema, and injury after tracheal intubation.

BCL6 inhibitor FX1 attenuates inflammatory responses in murine sepsis through strengthening BCL6 binding affinity to downstream target gene promoters.

BACKGROUND: Sepsis occurs when an infection triggers deranged inflammatory responses. There exists no efficacious treatment for this condition. The transcriptional repressor B-cell Lymphoma 6 (BCL6) is known to act as an inhibitor of macrophage-mediated inflammatory responses. FX1, a novel specific BCL6 BTB inhibitor, is able to attenuate activity of B cell-like diffuse large B cell lymphoma (ABC-DLBCL). Nevertheless, the effect of FX1 in inflammatory responses and sepsis remains unknown. OBJECTIVES: Here, we explored the effect and potential mechanisms of FX1 on the regulation of LPS-induced inflammatory responses in murine sepsis. METHOD: Mice models of LPS-induced sepsis were monitored for survival rate following FX1 administration. ELISA was used to assess how FX1 administration affected pro-inflammatory cytokines present in macrophages exposed to LPS and in the serum of mice sepsis models. Flow cytometric analysis, Western blot and qRT-PCR were performed to evaluate differences in macrophages immune responses after FX1 pre-treatment. Finally, the affinity of BCL6 binding to downstream target genes was checked by ChIP. RESULTS: The survival rate of mice models of LPS-induced sepsis was improved in following FX1 administration. FX1 decreased the production of inflammatory cytokines, attenuated macrophage infiltration activities and reduced monocytes chemotaxis activities, all of which suggest that FX1 exert anti-inflammatory effects. Mechanistically, FX1 may enhance the affinity of BCL6 binding to downstream target pro-inflammatory genes. CONCLUSIONS: These findings illustrated the anti-inflammatory properties and potential mechanisms of FX1 in sepsis caused by LPS. FX1 could potentially become a new immunosuppressive and anti-inflammatory drug candidate in sepsis therapy.

Dual-Specificity Phosphatase 26 Protects Against Nonalcoholic Fatty Liver Disease in Mice Through Transforming Growth Factor Beta-Activated Kinase 1 Suppression.

Nonalcoholic fatty liver disease (NAFLD), which has a wide global distribution, includes different stages ranging from simple steatosis to nonalcoholic steatohepatitis, advanced fibrosis, and liver cirrhosis according to the degree of severity. Chronic low-grade inflammation, insulin resistance, and lipid accumulation are the leading causes of NAFLD. To date, no effective medicine for NAFLD has been approved by governmental agencies. Our study demonstrated that the expression of dual-specificity phosphatase 26 (Dusp26), a member of the Dusp protein family, was decreased in the liver tissue of mice with hepatic steatosis and genetically obese (ob/ob) mice. In our study, hepatic steatosis, inflammatory responses, and insulin resistance were exacerbated in liver-specific Dusp26-knockout (KO) mice but ameliorated in liver-specific Dusp26-transgenic mice induced by a high-fat diet. In addition, the degree of liver fibrosis was aggravated in high-fat high-cholesterol diet-induced Dusp26-KO mice. We further found that the binding of Dusp26 to transforming growth factor beta-activated kinase 1 (TAK1) to block the phosphorylation of TAK1 regulated the TAK1-p38/c-Jun NH2-terminal kinase signaling axis to alleviate hepatic steatosis and metabolic disturbance. Conclusion: These findings suggest that Dusp26 is a good TAK1-dependent therapeutic target for NAFLD.

Nucleotide-Binding Oligomerization Domain-Like Receptor Protein 3 Deficiency in Vascular Smooth Muscle Cells Prevents Arteriovenous Fistula Failure Despite Chronic Kidney Disease.

Background The arteriovenous fistula ( AVF ) is the preferred hemodialysis access for patients with chronic kidney disease. Chronic kidney disease can increase neointima formation, which greatly contributes to AVF failure by an unknown mechanism. Our study aimed to determine the role of nucleotide-binding oligomerization domain-like receptor protein 3 ( NLRP 3) in neointima formation induced by experimental AVF s in the presence of chronic kidney disease. Methods and Results From our findings, NLRP 3 was upregulated in the intimal lesions of AVF s in both uremic mice and patients. Smooth muscle-specific knockout NLRP 3 mice exhibited markedly decreased neointima formation in the outflow vein of AVF s. Compared with primary vascular smooth muscle cells isolated from control mice, those isolated from smooth muscle-specific knockout NLRP 3 mice showed compromised proliferation, migration, phenotypic switching, and a weakened ability to activate mononuclear macrophages. To identify how NLRP 3 functions, several small-molecule inhibitors were used. The results showed that NLRP 3 regulates smooth muscle cell proliferation and migration through Smad2/3 phosphorylation rather than through caspase-1/interleukin-1 signaling. Unexpectedly, the selective NLRP 3-inflammasome inhibitor MCC 950 also repressed Smad2/3 phosphorylation and relieved chronic kidney disease-promoted AVF failure independent of macrophages. Conclusions Our findings suggest that NLRP 3 in vascular smooth muscle cells may play a crucial role in uremia-associated AVF failure and may be a promising therapeutic target for the treatment of AVF failure.

ADAM23 in Cardiomyocyte Inhibits Cardiac Hypertrophy by Targeting FAK - AKT Signaling.

Background Cardiac hypertrophy has been recognized as an important independent risk factor for the development of heart failure and increases the risk of cardiac morbidity and mortality. A disintegrin and metalloprotease 23 (ADAM23), a member of ADAM family, is involved in cancer and neuronal differentiation. Although ADAM23 is expressed in the heart, the role of ADAM23 in the heart and in cardiac diseases remains unknown. Methods and Results We observed that ADAM23 expression is decreased in both failing human hearts and hypertrophic mice hearts. Cardiac-specific conditional ADAM23-knockout mice significantly exhibited exacerbated cardiac hypertrophy, fibrosis, and dysfunction, whereas transgenic mice overexpressing ADAM23 in the heart exhibited reduced cardiac hypertrophy in response to pressure overload. Consistent results were also observed in angiotensin II -induced neonatal rat cardiomyocyte hypertrophy. Mechanistically, ADAM23 exerts anti-hypertrophic effects by specifically targeting the focal adhesion kinase-protein kinase B (FAK-AKT) signaling cascade. Focal adhesion kinase inactivation by inhibitor ( PF -562271) greatly reversed the detrimental effects in ADAM23-knockout mice subjected to aortic banding. Conclusion Altogether, we identified ADAM23 as a negative regulator of cardiac hypertrophy through inhibiting focal adhesion kinase-protein kinase B signaling pathway, which could be a promising therapeutic target for this malady.

MicroRNA-21 Knockout Exacerbates Angiotensin II-Induced Thoracic Aortic Aneurysm and Dissection in Mice With Abnormal Transforming Growth Factor-ß-SMAD3 Signaling.

OBJECTIVE: Thoracic aortic aneurysm and dissection (TAAD) are severe vascular conditions. Dysfunctional transforming growth factor-ß (TGF-ß) signaling in vascular smooth muscle cells and elevated angiotensin II (AngII) levels are implicated in the development of TAAD. In this study, we investigated whether these 2 factors lead to TAAD in a mouse model and explored the possibility of using microRNA-21 (miR-21) for the treatment of TAAD. APPROACH AND RESULTS: TAAD was developed in Smad3 (mothers against decapentaplegic homolog 3) heterozygous (S3+/-) mice infused with AngII. We found that p-ERK (phosphorylated extracellular regulated protein kinases)- and p-JNK (phosphorylated c-Jun N-terminal kinase)-associated miR-21 was higher in TAAD lesions. We hypothesize that downregulation of miR-21 mitigate TAAD formation. However, Smad3+/-:miR-21-/- (S3+/-21-/-) mice exhibited conspicuous TAAD formation after AngII infusion. The vascular wall was dilated, and aortic rupture occurred within 23 days during AngII infusion. We then examined canonical and noncanonical TGF-ß signaling and found that miR-21 knockout in S3+/- mice increased SMAD7 and suppressed canonical TGF-ß signaling. Vascular smooth muscle cells lacking TGF-ß signals tended to switch from a contractile to a synthetic phenotype. The silencing of Smad7 with lentivirus prevented AngII-induced TAAD formation in S3+/-21-/- mice. CONCLUSIONS: Our study demonstrated that miR-21 knockout exacerbated AngII-induced TAAD formation in mice, which was associated with TGF-ß signaling dysfunction. Therapeutic strategies targeting TAAD should consider unexpected side effects associated with alterations in TGF-ß signaling.

A Disintegrin and Metalloprotease-22 Attenuates Hypertrophic Remodeling in Mice Through Inhibition of the Protein Kinase B Signaling Pathway.

BACKGROUND: Severe cardiac hypertrophy can lead to cardiac remodeling and even heart failure in the end, which is a leading cause of cardiovascular disease-related mortality worldwide. A disintegrin and metalloprotease-22 (ADAM22), a member of the transmembrane and secreted metalloendopeptidase family, participates in many biological processes, including those in the cardiovascular system. However, there is no explicit information on whether ADAM22 can regulate the process of cardiac hypertrophy; the effects that ADAM22 exerts in cardiac hypertrophy remain elusive. METHODS AND RESULTS: We observed significantly increased ADAM22 expression in failing hearts from patients with dilated cardiomyopathy and hypertrophic cardiomyopathy; the same trend was observed in mice induced by transaortic constriction and in neonatal rat cardiomyocytes treated by angiotensin II. Therefore, we constructed both cardiac-specific ADAM22 overexpression and knockout mice. At 4 weeks after transaortic constriction, cardiac-specific ADAM22 knockout, by the CRISPR/Cas9 (clustered regularly interspaced palindromic repeat (CRISPR)-Cas9) system, deteriorated the severity of cardiac hypertrophy in mice, whereas cardiac-specific ADAM22 overexpression mitigated the degrees of cardiac hypertrophy in mice. Similarly, altered ADAM22 expression modulated the angiotensin II-mediated cardiomyocyte hypertrophy in neonatal rat cardiomyocytes. After screening several signaling pathways, we found ADAM22 played a role in inhibition of protein kinase B (AKT) activation. Under the cardiac-specific ADAM22 knockout background, AKT activation was enhanced in transaortic constriction-induced mice and angiotensin II-stimulated neonatal rat cardiomyocytes, with a severe degree of cardiac hypertrophy. Treatment of a specific AKT inhibitor attenuated the transaortic constriction-enhanced AKT activation and cardiac hypertrophy in mice. CONCLUSIONS: The findings demonstrated that ADAM22 negatively regulates the AKT activation and the process of cardiac hypertrophy and may provide new insights into the pathobiological features of cardiac hypertrophy.