Hydrogen sulfide attenuates atherosclerosis induced by low shear stress by sulfhydrylating endothelium NFIL3 to restrain MEST mediated endothelial mesenchymal transformation.

BACKGROUND: Endothelial-mesenchymal transition (EndMT) induced by low shear stress plays an important role in the development of atherosclerosis. However, little is known about the correlation between hydrogen sulfide (H2S), a protective gaseous mediator in atherosclerosis and the process of EndMT. METHODS: We constructed a stable low-shear-stress-induced(2 dyn/cm2) EndMT model, acombined with the pretreatment method of hydrogen sulfide slow release agent(GYY4137). The level of MEST was detected in the common carotid artery of ApoE-/- mice with local carotid artery ligation. The effect of MEST on atherosclerosis development in vivo was verified using ApoE-/- mice were given tail-vein injection of endothelial-specific overexpressed and knock-down MEST adeno-associated virus (AAV). RESULTS: These findings confirmed that MEST is up-regulated in low-shear-stress-induced EndMT and atherosclerosis. In vivo experiments showed that MEST gene overexpression significantly promoted EndMT and aggravated the development of atherosclerotic plaques and MEST gene knockdown significantly inhibited EndMT and delayed the process of atherosclerosis. In vitro, H2S inhibits the expression of MEST and EndMT induced by low shear stress and inhibits EndMT induced by MEST overexpression. Knockdown of NFIL3 inhibit the up regulation of MEST and EndMT induced by low shear stress in HUVECs. CHIP-qPCR assay and Luciferase Reporter assay confirmed that NFIL3 binds to MEST DNA, increases its transcription and H2S inhibits the binding of NFIL3 and MEST DNA, weakening NFIL3's transcriptional promotion of MEST. Mechanistically, H2S increased the sulfhydrylation level of NFIL3, an important upstream transcription factors of MEST. In part, transcription factor NFIL3 restrain its binding to MEST DNA by sulfhydration. CONCLUSIONS: H2S negatively regulate the expression of MEST by sulfhydrylation of NFIL3, thereby inhibiting low-shear-stress-induced EndMT and atherosclerosis.

WITHDRAWN: Expression of Tmem41b and MMP13 associated with poor outcome in osteosarcomas.

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Feasibility and Safety of Transgastric Natural Orifice Transluminal Endoscopic Surgery in the Diagnosis of Ascites of Unknown Origin.

Objective: The purpose of this study was to evaluate the feasibility and safety of transgastric natural orifice transluminal endoscopic surgery (TG-NOTES) combined with biopsy in the diagnosis of unknown ascites. Method: This retrospective study used data from the first affiliated hospital of Nanchang university on 51 patients who were diagnosed with ascites of unknown origin between January 2013 and May 2019 and experienced peritoneal biopsy through TG-NOTES. The outcome measures included diagnostic accuracy and procedure-related adverse events. Results: TG-NOTES was performed successfully in 46 of 51 patients, tuberculous ascites in 38 cases, carcinomatous ascites in 4 cases, cirrhotic ascites in 1 case, and 3 cases showed no obvious abnormalities in pathological result. Five cases failed to be diagnosed because of abdominal adhesions. The diagnostic rate of TG-NOTES was 84.3%. There were no severe procedure-related adverse events and no mortality. All patients had good wound healing and no complaint of discomfort on follow-up. Conclusion: The majority of ascites of unknown origin can be expounded through TG-NOTES combined with biopsy without severe complication, therefore, it is a feasible and safe method to detect the cause of unexplained ascites.

Clinical analysis of 45 cases of perforation were identified during endoscopic retrograde cholangiopancreatography procedure.

Background: Endoscopic retrograde cholangiopancreatography (ERCP) has become an important method to diagnose and treat biliary-pancreatic diseases. Perforations are infrequent but serious complications can occur during ERCPs. However, it is unclear which patients are suitable for surgery and when these patients should receive surgery. Aim: To analyze the outcome of 45 patients with endoscopic retrograde cholangiopancreatography (ERCP) related perforation. Materials and methods: We retrospectively reviewed all 45 patients with ERCP-related perforation between January 2003 and December 2017, and observed the location and causes of perforation, treatment strategies, and mortality. Results: Twenty thousand four hundred and seventy-nine patients received ERCP procedures from January 2003 to December 2017 in our digestive endoscopy center. Forty-five patients suffered from ERCP-related perforations. The incidence rate of ERCP-related perforations was 0.22%. Twenty-six patients suffered from periampullary perforations, 15 patients suffered from duodenal wall perforations, 1 patient suffered from a fundus perforation, 1 patient suffered from a residual gallbladder duct perforation, 1 patient suffered from a papillary diverticulum perforation, and 1 patient suffered from an intrahepatic bile duct perforation. Six patients with duodenal perforations underwent surgery, and the other patients received conservative treatment. One patient with a duodenal perforation and ERCP-related pancreatitis died of heart failure, and all the other patients recovered. The mortality rate was 2.2%. Conclusion: Endoscopic closure is seen as the first method for treating Stapfer type I perforations in the early phase, and surgery is seen as a remedial method when local treatment was failed. The Stapfer type II to type IV perforations can recover by conservative treatment.

Small Interfering RNA for Gliomas Treatment: Overcoming Hurdles in Delivery.

Gliomas are central nervous system tumors originating from glial cells, whose incidence and mortality rise in coming years. The current treatment of gliomas is surgery combined with chemotherapy or radiotherapy. However, developing therapeutic resistance is one of the significant challenges. Recent research suggested that small interfering RNA (siRNA) has excellent potential as a therapeutic to silence genes that are significantly involved in the manipulation of gliomas' malignant phenotypes, including proliferation, invasion, metastasis, therapy resistance, and immune escape. However, it is challenging to deliver the naked siRNA to the action site in the cells of target tissues. Therefore, it is urgent to develop delivery strategies to transport siRNA to achieve the optimal silencing effect of the target gene. However, there is no systematic discussion about siRNAs' clinical potential and delivery strategies in gliomas. This review mainly discusses siRNAs' delivery strategies, especially nanotechnology-based delivery systems, as a potential glioma therapy. Moreover, we envisage the future orientation and challenges in translating these findings into clinical applications.

Soluble Klotho-integrin ß1/ERK1/2 pathway ameliorates myocardial fibrosis in diabetic cardiomyopathy.

Soluble Klotho (sKL) is closely related to insulin resistance, which is a major factor in the progression of diabetic cardiomyopathy (DCM). The purpose of this study was to investigate the role of sKL in the regulation of DCM and the mechanism involved. A mouse model of type 2 diabetes was induced by high-fat diet and streptozotocin injection. An insulin-resistant cardiac fibroblast model was established by high glucose and high insulin. KL gene overexpression was achieved in vivo and vitro through transfection with an adenovirus-harboring KL-cDNA. Gene overexpression was used to evaluate the role of sKL in the pathophysiologic characteristics of DCM. Insulin-resistant cardiac fibroblasts reduced sKL expression and collagen deposition. Diabetic mice constructed by streptozotocin exhibited severe insulin resistance, inflammation, fibrosis, left ventricular dysfunction, and sKL downregulation. The overexpression of sKL mitigated insulin resistance and metabolic disturbance; inflammation, fibrosis, and upregulated collagen I/III content ratio in diabetic state were significantly reduced. Our findings were accompanied by notable moderation of cardiac function. Further, blunted phosphorylation of Akt was restored with sKL gene overexpression, and activated phosphorylation of extracellular signal-regulated kinase 1/2 in DCM was reduced. Our results suggest that sKL protein overexpression exerts a defensive measure by ameliorating selective insulin resistance in mouse DCM, thus revealing its underlying mechanism for potential human DCM treatment.

Effective control of large deletions after double-strand breaks by homology-directed repair and dsODN insertion.

BACKGROUND: After repairing double-strand breaks (DSBs) caused by CRISPR-Cas9 cleavage, genomic damage, such as large deletions, may have pathogenic consequences. RESULTS: We show that large deletions are ubiquitous but are dependent on editing sites and cell types. Human primary T cells display more significant deletions than hematopoietic stem and progenitor cells (HSPCs), whereas we observe low levels in induced pluripotent stem cells (iPSCs). We find that the homology-directed repair (HDR) with single-stranded oligodeoxynucleotides (ssODNs) carrying short homology reduces the deletion damage by almost half, while adeno-associated virus (AAV) donors with long homology reduce large deletions by approximately 80%. In the absence of HDR, the insertion of a short double-stranded ODN by NHEJ reduces deletion indexes by about 60%. CONCLUSIONS: Timely bridging of broken ends by HDR and NHEJ vastly decreases the unintended consequences of dsDNA cleavage. These strategies can be harnessed in gene editing applications to attenuate unintended outcomes.

Super-enhancers: a new frontier for epigenetic modifiers in cancer chemoresistance.

Although new developments of surgery, chemotherapy, radiotherapy, and immunotherapy treatments for cancer have improved patient survival, the emergence of chemoresistance in cancer has significant impacts on treatment effects. The development of chemoresistance involves several polygenic, progressive mechanisms at the molecular and cellular levels, as well as both genetic and epigenetic heterogeneities. Chemotherapeutics induce epigenetic reprogramming in cancer cells, converting a transient transcriptional state into a stably resistant one. Super-enhancers (SEs) are central to the maintenance of identity of cancer cells and promote SE-driven-oncogenic transcriptions to which cancer cells become highly addicted. This dependence on SE-driven transcription to maintain chemoresistance offers an Achilles' heel for chemoresistance. Indeed, the inhibition of SE components dampens oncogenic transcription and inhibits tumor growth to ultimately achieve combined sensitization and reverse the effects of drug resistance. No reviews have been published on SE-related mechanisms in the cancer chemoresistance. In this review, we investigated the structure, function, and regulation of chemoresistance-related SEs and their contributions to the chemotherapy via regulation of the formation of cancer stem cells, cellular plasticity, the microenvironment, genes associated with chemoresistance, noncoding RNAs, and tumor immunity. The discovery of these mechanisms may aid in the development of new drugs to improve the sensitivity and specificity of cancer cells to chemotherapy drugs.

KLF5-mediated Eppk1 expression promotes cell proliferation in cervical cancer via the p38 signaling pathway.

BACKGROUND: Epiplakin1 (Eppk1) is part of epidermal growth factor (EGF) signal and takes part in reorganization of cytoskeleton and cell proliferation. However, the role of Eppk1 in cervical cancer (CC) remains unknown. METHODS: To express Eppk1 and KLF5 and their correlation, we used RNA-sequence, RT-qPCR, TCGA database and immunofluorescence staining in vitro and in different pathological cervical tissues. In CC cell lines, we tested adenovirus-mediated over expression or knockdown of KLF5 and siRNA-mediated knockdown of Eppk1 and a suiting assessment of cell proliferation and cell signaling by western blot and CCK8 tests. We studied the mechanism by which KLF5 regulates Eppk1 expression by reporter gene test and chromatin immunoprecipitation test. RESULTS: Eppk1 expression promoted in CC tissues and cell lines compared with increased KLF5 expression. The results of immunofluorescence staining further showed the increased co-expression of Eppk1 and KLF5 correlated substantially with tumorigenesis in cervical tissues. Overexpression of KLF5 significantly increased Eppk1 expression at transcription and translation levels. Conversely, the knockdown of KLF5 by siRNA against KLF5 decreased Eppk1 expression. Mechanically, KLF5 activated Eppk1 transcription by direct binding to the Eppk1 promoter. Gain- and loss-of-function experiments reported that KLF5 promoted cell proliferation in Hela partly dependent on Eppk1 upregulation. Besides, KLF5-mediated activation of p38 signaling significantly decreased after Eppk1 knockdown compared with decline of proliferation, suggesting that Eppk1 lies upstream of p38 signaling affecting cell proliferation. Finally, Eppk1 expression is positively correlated with tumor size in clinicopathological features of CC. CONCLUSIONS: Eppk1 may be an effective therapeutic target for affecting p38 signaling pathway and cell proliferation in cervical cancer.

Tranexamic Acid Combined with Compression Bandage Following Total Knee Arthroplasty Promotes Blood Coagulation: A Retrospective Analysis.

OBJECTIVE: This paper included a retrospective review of the effect of tranexamic acid (TXA) combined with pressure bandaging on hemostasis of patients who received a unilateral total knee arthroplasty (TKA) from 2017 to 2019. METHODS: A total of 197 patients undergoing TKA were chosen to be classified into 2 groups, the compression bandage control group and compression bandage combined with TXA observation group. The patients received blood routine examination when they were in the 1st, 3rd, and 6th days of before and postoperation. Some parameters, such as hemoglobin (Hb), C-reactive protein (CRP), D-dimer value, fibrinogen, prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), international normalized ratio (INR), and erythrocyte sedimentation rate (ESR), were also investigated. RESULTS: In our research, the mean age was 66.54 ± 7.95 years. No difference was found in patient sex (P = 0.876) and age (P = 0.749) between groups. No differences were found in the levels of Hb, fibrinogen, TT, and INR between the 2 groups at each period (P > 0.05). The difference of PT was significantly different on the 1st day (P = 0.011), 3rd day (P = 0.010), and 6th day (P = 0.004) after surgery. Besides, the changes in APTT in observation group were clearly higher compared with the control group on the 3rd day (P = 0.001) and 6th day (P = 0.001). On the 3rd and 6th days after operation, the CRP level of the two groups increased continuously, and the CRP level was significantly higher in the observation group in comparison with the control group (P = 0.008, P = 0.010). On 1st and 3rd days after surgery, compared to the control group, the D-dimer level of patients in the observation group was distinctly fewer (P = 0.001, P = 0.027). CONCLUSION: TXA combined with compression bandage is a potential option for the reduction of bleeding after TKA.

CD226 deletion improves post-infarction healing via modulating macrophage polarization in mice.

Macrophages are essential for wound repair after myocardial infarction (MI). CD226, a member of immunoglobulin superfamily, is expressed on inflammatory monocytes, however, the role of CD226 in infarct healing and the effect of CD226 on macrophage remain unknown. Methods: Wild type and CD226 knockout (CD226 KO) mice were subjected to permanent coronary ligation. CD226 expression, cardiac function and ventricular remodeling were evaluated. Profile of macrophages, myofibroblasts, angiogenesis and monocytes mobilization were determined. Results: CD226 expression increased in the infarcted heart, with a peak on day 7 after MI. CD226 KO attenuated infarct expansion and improved infarct healing after MI. CD226 deletion resulted in increased F4/80+ CD206+ M2 macrophages and diminished Mac-3+ iNOS+ M1 macrophages accumulation in the infarcted heart, as well as enrichment of α-smooth muscle actin positive myofibroblasts and Ki67+ CD31+ endothelial cells, leading to increased reparative collagen deposition and angiogenesis. Furthermore, CD226 deletion restrained inflammatory monocytes mobilization, as revealed by enhanced retention of Ly6Chi monocytes in the spleen associated with a decrease of Ly6Chi monocytes in the peripheral blood, whereas local proliferation of macrophage in the ischemic heart was not affected by CD226 deficiency. In vitro studies using bone marrow-derived macrophages showed that CD226 deletion potentiated M2 polarization and suppressed M1 polarization. Conclusion: CD226 expression is dramatically increased in the infarcted heart, and CD226 deletion improves post-infarction healing and cardiac function by favoring macrophage polarization towards reparative phenotype. Thus, inhibition of CD226 may represent a novel therapeutic approach to improve wound healing and cardiac function after MI.

Inhibition of the ox-LDL-Induced Pyroptosis by FGF21 of Human Umbilical Vein Endothelial Cells Through the TET2-UQCRC1-ROS Pathway.

Fibroblast growth factor 21 (FGF21) is a hormone-like member of the FGF family that is associated with cell death in atherosclerosis. However, its underlying mechanisms remain unclear. In this study, the effect of FGF21 on endothelial cell pyroptosis and its potential mechanisms were investigated. Results showed that FGF21 inhibits oxidized low-density lipoprotein (ox-LDL)-induced pyroptosis and related molecular expression in human umbilical vein endothelial cells (HUVECs). Mitochondrial function was damaged by ox-LDL and restored by FGF21. A mechanism proved that ubiquinol cytochrome c reductase core protein I (UQCRC1) was downregulated by ox-LDL and upregulated by FGF21. Further, the silencing of UQCRC1 aggravated HUVEC pyroptosis and impaired mitochondrial function and reactive oxygen species (ROS) production. Moreover, Tet methylcytosine dioxygenase (TET2) was involved in the regulation of UQCRC1 expression and pyroptosis. In summary, FGF21 inhibited ox-LDL-induced HUVEC pyroptosis through the TET2-UQCRC1-ROS pathway.

Risk factors for delayed hemorrhage after endoscopic sphincterotomy.

BACKGROUND: Hemorrhage is one of the most serious complications of endoscopic sphincterotomy (EST). The risk factors for delayed hemorrhage are not clear. This study aimed to explore the risk factors for post-EST delayed hemorrhage and suggest some precautionary measures. METHODS: This study analyzed 8477 patients who successfully underwent endoscopic retrograde cholangiopancreatography (ERCP) and EST between January 2007 and June 2015 in the First Affiliated Hospital of Nanchang University. Univariate and multivariate analyses were performed to find the risk factors for delayed hemorrhage after EST. RESULTS: Of the 8477 patients screened, 137 (1.62%) experienced delayed hemorrhage. Univariate analysis showed that male, the severity of jaundice, duodenal papillary adenoma and carcinoma, diabetes, intraoperative bleeding, moderate and large incisions, and directional deviation of incision were risk factors for post-EST delayed hemorrhage (P < 0.05). Multivariate analysis showed that intraoperative bleeding [odds ratio (OR) = 3.326; 95% CI: 1.785-6.196; P < 0.001] and directional deviation of incision (OR = 2.184; 95% CI: 1.266-3.767; P = 0.005) were independent risk factors for post-EST delayed hemorrhage. CONCLUSIONS: Delayed hemorrhage is the most common and dangerous complication of EST. Intraoperative bleeding and directional deviation of incision are independent risk factors for post-EST delayed hemorrhage.

Hypermethylation of Single CpG Dinucleotides at the Promoter of CXCL13 Gene Promoting Cell Migration in Cervical Cancer.

BACKGROUND: Chemokine 13 (CXCL13) and its chemokine receptor 5 (CXCR5) are involved in the onset of various types of cancer. However, their role in cervical cancer (CC) remains unknown. OBJECTIVE: To investigate the role of chemokine 13 (CXCL13) and its receptor in CC. METHODS: The expression of CXCL13/CXCR5 and the infiltration of CXCR5+CD8+ T cells in CC, cervical intraepithelial neoplasia (CIN), normal cervical epithelial (NCE) tissues, and in CC cell lines were analysed and the associated clinical significance was determined. In vitro, CXCL13 overexpression and DNA methyltransferase inhibition (through S110) were used to investigate the biological function and the underlying mechanism that regulates CXCL13 expression. Tumor growth and liver metastasis were also evaluated in the xenogenous subcutaneously implant model. RESULTS: CXCL13/CXCR5 expression levels and the infiltration of CXCR5+CD8+ T cells were significantly decreased in CC tissues compared with CIN and NCE tissues. CXCL13 downregulation was significantly correlated with the FIGO stages, lymph node metastasis, interstitial infiltration depth, and pathological grade. The overexpression of CXCL13 suppressed CC cell migration. CXCL13 downregulation was associated with hypermethylation in CC cell lines, and primary tumor biopsies. Furthermore, a CpG dinucleotide at the HIF-1a transcription factor motifs in the promoter element of CXCL13 was consistently methylated in CC cells and associated with HIF-1a. CXCL13 overexpression and S110 treatment dramatically repressed tumor growth and liver metastasis in the xenograft model; whereas it's low expression increased the risk of death in CC patients. CONCLUSION: DNA methylation-dependent CXCL13 downregulation may promote cervical carcinogenesis and progression.

Clinical evaluation of endoscopic resection for treatment of large gastric stromal tumors.

BACKGROUND: Gastric stromal tumor is a digestive tract mesenchymal tumor with malignant potential, and endoscopic techniques have been widely used in the treatment of gastric stromal tumors, but there is still controversy over their use for large gastric stromal tumors (≥ 3 cm). AIM: To evaluate the clinical long-term efficacy and safety of endoscopic resection for large (≥ 3 cm) gastric stromal tumors. METHODS: All patients who underwent endoscopic resection or surgery at our hospital from 2012 to 2017 for pathologically confirmed gastric stromal tumor with a maximum diameter of ≥ 3 cm were collected. The clinical data, histopathologic characteristics of the tumors, and long-term outcomes were recorded. RESULTS: A total of 261 patients were included, including 37 patients in the endoscopy group and 224 patients in the surgical group. In the endoscopy group, the maximum tumor diameter was 3-8 cm; the male: Female ratio was 21/16; 34 cases had low-risk tumors, 3 had intermediate-risk, and 0 had high-risk; the mean follow-up time was 30.29 ± 19.67 mo, no patient was lost to follow-up, and no patient received chemotherapy after operation; two patients with recurrence had low-risk stromal tumors, and neither had complete resection under endoscopy. In the surgical group, the maximum tumor diameter was 3-22 cm; the male: Female ratio was 121/103; 103 cases had low-risk tumors, 75 had intermediate-risk, and 46 had high-risk; the average follow-up time was 38.83 ± 21.50 mo, 53 patients were lost to follow-up, and 8 patients had recurrence after operation (6 cases had high-risk tumors, 1 had intermediate-risk, and 1 had low-risk). The average tumor volume of the endoscopy group was 26.67 ± 26.22 cm3 (3.75-120), all of which were less than 125 cm3. The average volume of the surgical group was 273.03 ± 609.74 cm3 (7-4114). Among all patients with a tumor volume < 125 cm3, 7 with high-risk stromal tumors in the surgical group (37.625 cm3 to 115.2 cm3) accounted for 3.8% (7/183); of those with a tumor volume < 125 cm3, high-risk patients accounted for 50% (39/78). We found that 57.1% (12/22) of patients with high-risk stromal tumors also had endoscopic surface ulcer bleeding and tumor liquefaction on ultrasound or abdominal computed tomography; the ratio of tumors positive for both in high-risk stromal tumors with a volume < 125 cm3 was 60% (3/5). CONCLUSION: Endoscopic treatment is safe for 95.5% of patients with gastric stromal tumors with a tumor diameter ≥ 3 cm and a volume of < 125 cm3 without endoscopic surface ulcer bleeding or CT liquefaction.

Fibroblast growth factor-21 alleviates hypoxia/reoxygenation injury in H9c2 cardiomyocytes by promoting autophagic flux.

Fibroblast growth factor (FGF)­21, a member of the family of FGFs, exhibits protective effects against myocardial ischemia and ischemia/reperfusion injury; it is also an enhancer of autophagy. However, the mechanisms underlying the protective role of FGF­21 against cardiomyocyte hypoxia/reoxygenation (H/R) injury remain unclear. The present study aimed to investigate the effect of FGF­21 on H9c2 cardiomyocyte injury induced by H/R and the mechanism associated with changes in autophagy. Cultured H9c2 cardiomyocytes subjected to hypoxia were treated with a vehicle or FGF­21 during reoxygenation. The viability of H9c2 rat cardiomyocytes was measured using Cell Counting Kit­8 and trypan blue exclusion assays. The contents of creatine kinase (CK) and creatine kinase isoenzymes (CK­MB), cardiac troponin I (cTnT), cardiac troponin T (cTnI) and lactate dehydrogenase (LDH) in culture medium were detected with a CK, CK­MB, cTnT, cTnI and LDH assay kits. The protein levels were examined by western blot analysis. Autophagic flux was detected by Ad­mCherry­GFP­LC3B autophagy fluorescent adenovirus reagent. The results indicated that FGF­21 alleviated H/R­induced H9c2 myocardial cell injury and enhanced autophagic flux during H/R, and that this effect was antagonized by co­treatment with 3­methyladenine, an autophagy inhibitor. Furthermore, FGF­21 increased the expression levels of Beclin­1 and Vps34 proteins, but not of mechanistic target of rapamycin. These data indicate that FGF­21 treatment limited H/R injury in H9c2 cardiomyocytes by promoting autophagic flux through upregulation of the expression levels of Beclin­1 and Vps34 proteins.

Vitamin C down-regulate apo(a) expression via Tet2-dependent DNA demethylation in HepG2 cells.

Lipoprotein(a)[Lp(a)] is a risk factor for coronary heart diseases. However, the metabolism of this protein remains poorly understood. Efficient and specific drugs that can decrease high plasma levels of Lp(a) have not been developed yet. Vitamin C is responsible for maintaining the catalytic activity of a group of iron and 2-oxoglutarate (2OG)-dependent dioxygenases and induces the generation of 5-hydroxymethylcytosine (5hmC) via Ten-eleven translocation (Tet) dioxygenases. In addition, It has been reported vitamin C deficiency induces atherosclerosis and increases Lp(a) and apo(a) plasma levels in Lp(a)+ mice. However, the mechanism is still unclear. In this study, we investigated the effects of vitamin C on apo(a) expression and the possible molecular mechanism of vitamin C that influences apolipoprotein(a) [apo(a)] biosynthesis in HepG2 cells. Results showed that vitamin C significantly inhibited the expression and secretion levels of apo(a). Vitamin C can also increase ELK1 expression and hydroxymethylation of ELK1 promoter and the globle DNA in HepG2 cells. In addition, the effects of vitamin C inhibiting the apo(a) expression were attenuated by ELK1siRNA and Tet2siRNA. These results suggested vitamin C down-regulate apo(a) expression via Tet2-dependent DNA demethylation in HepG2 cells.

Tet methylcytosine dioxygenase 2 inhibits atherosclerosis via upregulation of autophagy in ApoE-/- mice.

Tet methylcytosine dioxygenase 2 (TET2) mediates the conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC). The loss of TET2 is associated with advanced atherosclerotic lesions. Our previous study showed that TET2 improves endothelial cell function by enhancing endothelial cell autophagy. Accordingly, this study determined the role of TET2 in atherosclerosis and potential mechanisms. In ApoE-/- mice fed high-fat diet, TET2 overexpression markedly decreased atherosclerotic lesions with uniformly increased level of 5hmC and decreased level of 5mC in genomic DNA. TET2 overexpression also promoted autophagy and downregulated inflammation factors, such as vascular cell adhesion molecule 1, intercellular adhesion molecule 1, monocyte chemotactic protein 1, and interleukin-1. Consistently, TET2 knockdown with small hairpin RNA (shRNA) in ApoE-/- mice decreased 5hmC and increased 5mC levels in atherosclerotic lesions. Meanwhile, autophagy was inhibited and atherosclerotic lesions progressed with an unstable lesion phenotype characterized by large lipid core, macrophage accumulation, and upregulated inflammation factor expression. Experiments with the cultured endothelial cells revealed that oxidized low-density lipoprotein (ox-LDL) inhibited endothelial cell autophagy. TET2 shRNA strengthened impaired autophagy and autophagic flux in the ox-LDL-treated endothelial cells. TET2 overexpression reversed these effects by decreasing the methylation level of the Beclin 1 promoter, which contributed to the downregulation of inflammation factors. Overall, we identified that TET2 was downregulated during the pathogenesis of atherosclerosis. The downregulation of TET2 promotes the methylation of the Beclin 1 promoter, leading to endothelial cell autophagy, impaired autophagic flux, and inflammatory factor upregulation. Upregulation of TET2 may be a novel therapeutic strategy for treating atherosclerosis.

Dual effects of VEGF-B on activating cardiomyocytes and cardiac stem cells to protect the heart against short- and long-term ischemia-reperfusion injury.

AIMS: To investigate whether vascular endothelial growth factor B (VEGF-B) improves myocardial survival and cardiac stem cell (CSC) function in the ischemia-reperfusion (I/R) heart and promotes CSC mobilization and angiogenesis. METHODS AND RESULTS: One hour after myocardial ischemia and infarction, rats were treated with recombinant human VEGF-B protein following 24 h or 7 days of myocardial reperfusion. Twenty-four hours after myocardial I/R, VEGF-B increased pAkt and Bcl-2 levels, reduced p-p38MAPK, LC3-II/I, beclin-1, CK, CK-MB and cTnt levels, triggered cardiomyocyte protection against I/R-induced autophagy and apoptosis, and contributed to the decrease of infarction size and the improvement of heart function during I/R. Simultaneously, an in vitro hypoxia-reoxygenation (H/R)-induced H9c2 cardiomyocyte injury model was used to mimic I/R injury model in vivo; in this model, VEGF-B decreased LDH release, blocked H/R-induced apoptosis by inhibiting cell autophagy, and these special effects could be abolished by the autophagy inducer, rapamycin. Mechanistically, VEGF-B markedly activated the Akt signaling pathway while slightly inhibiting p38MAPK, leading to the blockade of cell autophagy and thus protecting cardiomyocyte from H/R-induced activation of the intrinsic apoptotic pathway. Seven days after I/R, VEGF-B induced the expression of SDF-1α and HGF, resulting in the massive mobilization and homing of c-Kit positive cells, triggering further angiogenesis and vasculogenesis in the infracted heart and contributing to the improvement of I/R heart function. CONCLUSION: VEGF-B could contribute to a favorable short- and long-term prognosis for I/R via the dual manipulation of cardiomyocytes and CSCs.

PI3K/Akt/FoxO3a signaling mediates cardioprotection of FGF-2 against hydrogen peroxide-induced apoptosis in H9c2 cells.

Cardiovascular disease is a growing major global public health problem. Oxidative stress is regarded as one of the key regulators of pathological physiology, which eventually leads to cardiovascular disease. However, mechanisms by which FGF-2 rescues cells from oxidative stress damage in cardiovascular disease is not fully elucidated. Herein this study was designed to investigate the protective effects of FGF-2 in H2O2-induced apoptosis of H9c2 cardiomyocytes, as well as the possible signaling pathway involved. Apoptosis of H9c2 cardiomyocytes was induced by H2O2 and assessed using methyl thiazolyl tetrazolium assay, Hoechst, and TUNEL staining. Cells were pretreated with PI3K/Akt inhibitor LY294002 to investigate the possible PI3K/Akt pathways involved in the protection of FGF-2. The levels of p-Akt, p-FoxO3a, and Bim were detected by immunoblotting. Stimulation with H2O2 decreased the phosphorylation of Akt and FoxO3a, and induced nuclear localization of FoxO3a and apoptosis of H9c2 cells. These effects of H2O2 were abrogated by pretreatment with FGF-2. Furthermore, the protective effects of FGF-2 were abolished by PI3K/Akt inhibitor LY294002. In conclusion, our data suggest that FGF-2 protects against H2O2-induced apoptosis of H9c2 cardiomyocytes via activation of the PI3K/Akt/FoxO3a pathway.