Vascular injury activates the ELK1/SND1/SRF pathway to promote vascular smooth muscle cell proliferative phenotype and neointimal hyperplasia.

BACKGROUND: Vascular smooth muscle cell (VSMC) proliferation is the leading cause of vascular stenosis or restenosis. Therefore, investigating the molecular mechanisms and pivotal regulators of the proliferative VSMC phenotype is imperative for precisely preventing neointimal hyperplasia in vascular disease. METHODS: Wire-induced vascular injury and aortic culture models were used to detect the expression of staphylococcal nuclease domain-containing protein 1 (SND1). SMC-specific Snd1 knockout mice were used to assess the potential roles of SND1 after vascular injury. Primary VSMCs were cultured to evaluate SND1 function on VSMC phenotype switching, as well as to investigate the mechanism by which SND1 regulates the VSMC proliferative phenotype. RESULTS: Phenotype-switched proliferative VSMCs exhibited higher SND1 protein expression compared to the differentiated VSMCs. This result was replicated in primary VSMCs treated with platelet-derived growth factor (PDGF). In the injury model, specific knockout of Snd1 in mouse VSMCs reduced neointimal hyperplasia. We then revealed that ETS transcription factor ELK1 (ELK1) exhibited upregulation and activation in proliferative VSMCs, and acted as a novel transcription factor to induce the gene transcriptional activation of Snd1. Subsequently, the upregulated SND1 is associated with serum response factor (SRF) by competing with myocardin (MYOCD). As a co-activator of SRF, SND1 recruited the lysine acetyltransferase 2B (KAT2B) to the promoter regions leading to the histone acetylation, consequently promoted SRF to recognize the specific CArG motif, and enhanced the proliferation- and migration-related gene transcriptional activation. CONCLUSIONS: The present study identifies ELK1/SND1/SRF as a novel pathway in promoting the proliferative VSMC phenotype and neointimal hyperplasia in vascular injury, predisposing the vessels to pathological remodeling. This provides a potential therapeutic target for vascular stenosis.

Tudor-SN promotes cardiomyocyte proliferation and neonatal heart regeneration through regulating the phosphorylation of YAP.

BACKGROUND: The neonatal mammalian heart exhibits considerable regenerative potential following injury through cardiomyocyte proliferation, whereas mature cardiomyocytes withdraw from the cell cycle and lose regenerative capacities. Therefore, investigating the mechanisms underlying neonatal cardiomyocyte proliferation and regeneration is crucial for unlocking the regenerative potential of adult mammalian heart to repair damage and restore contractile function following myocardial injury. METHODS: The Tudor staphylococcal nuclease (Tudor-SN) transgenic (TG) or cardiomyocyte-specific knockout mice (Myh6-Tudor-SN -/-) were generated to investigate the role of Tudor-SN in cardiomyocyte proliferation and heart regeneration following apical resection (AR) surgery. Primary cardiomyocytes isolated from neonatal mice were used to assess the influence of Tudor-SN on cardiomyocyte proliferation in vitro. Affinity purification and mass spectrometry were employed to elucidate the underlying mechanism. H9c2 cells and mouse myocardia with either overexpression or knockout of Tudor-SN were utilized to assess its impact on the phosphorylation of Yes-associated protein (YAP), both in vitro and in vivo. RESULTS: We previously identified Tudor-SN as a cell cycle regulator that is highly expressed in neonatal mice myocardia but downregulated in adults. Our present study demonstrates that sustained expression of Tudor-SN promotes and prolongs the proliferation of neonatal cardiomyocytes, improves cardiac function, and enhances the ability to repair the left ventricular apex resection in neonatal mice. Consistently, cardiomyocyte-specific knockout of Tudor-SN impairs cardiac function and retards recovery after injury. Tudor-SN associates with YAP, which plays important roles in heart development and regeneration, inhibiting phosphorylation at Ser 127 and Ser 397 residues by preventing the association between Large Tumor Suppressor 1 (LATS1) and YAP, correspondingly maintaining stability and promoting nuclear translocation of YAP to enhance the proliferation-related genes transcription. CONCLUSION: Tudor-SN regulates the phosphorylation of YAP, consequently enhancing and prolonging neonatal cardiomyocyte proliferation under physiological conditions and promoting neonatal heart regeneration after injury.

Endothelial colony-forming cell-derived exosomal miR-21-5p regulates autophagic flux to promote vascular endothelial repair by inhibiting SIPL1A2 in atherosclerosis.

BACKGROUND: Percutaneous transluminal coronary angioplasty (PTCA) represents an efficient therapeutic method for atherosclerosis but conveys a risk of causing restenosis. Endothelial colony-forming cell-derived exosomes (ECFC-exosomes) are important mediators during vascular repair. This study aimed to investigate the therapeutic effects of ECFC-exosomes in a rat model of atherosclerosis and to explore the molecular mechanisms underlying the ECFC-exosome-mediated effects on ox-LDL-induced endothelial injury. METHODS: The effect of ECFC-exosome-mediated autophagy on ox-LDL-induced human microvascular endothelial cell (HMEC) injury was examined by cell counting kit-8 assay, scratch wound assay, tube formation assay, western blot and the Ad-mCherry-GFP-LC3B system. RNA-sequencing assays, bioinformatic analysis and dual-luciferase reporter assays were performed to confirm the interaction between the miR-21-5p abundance of ECFC-exosomes and SIPA1L2 in HMECs. The role and underlying mechanism of ECFC-exosomes in endothelial repair were explored using a high-fat diet combined with balloon injury to establish an atherosclerotic rat model of vascular injury. Evans blue staining, haematoxylin and eosin staining and western blotting were used to evaluate vascular injury. RESULTS: ECFC-exosomes were incorporated into HMECs and promoted HMEC proliferation, migration and tube formation by repairing autophagic flux and enhancing autophagic activity. Subsequently, we demonstrated that miR-21-5p, which is abundant in ECFC-exosomes, binds to the 3' untranslated region of SIPA1L2 to inhibit its expression, and knockout of miR-21-5p in ECFC-exosomes reversed ECFC-exosome-decreased SIPA1L2 expression in ox-LDL-induced HMEC injury. Knockdown of SIPA1L2 repaired autophagic flux and enhanced autophagic activity to promote cell proliferation in ox-LDL-treated HMECs. ECFC-exosome treatment attenuated vascular endothelial injury, regulated lipid balance and activated autophagy in an atherogenic rat model of vascular injury, whereas these effects were eliminated with ECFC-exosomes with knockdown of miR-21-5p. CONCLUSIONS: Our study demonstrated that ECFC-exosomes protect against atherosclerosis- or PTCA-induced vascular injury by rescuing autophagic flux and inhibiting SIAP1L2 expression through delivery of miR-21-5p. Video Abstract.

Thoracic Endovascular Repair for Aortic Arch Pathologies with Surgeon Modified Fenestrated Stent Grafts: A Multicentre Retrospective Study.

OBJECTIVE: To evaluate the outcome of thoracic endovascular repair (TEVAR) for aortic arch pathologies with surgeon modified fenestrated stent grafts. METHODS: A multicentre, retrospective study consisting of consecutive patients from seven centres treated with surgeon modified fenestrated stent grafts for aortic arch pathologies was conducted. A technique to align fenestrations and supra-aortic vessels was applied. Rates of technical success, mortality, complications, and re-interventions were evaluated. RESULTS: Between February 2016 and January 2020, 513 consecutive patients with aortic arch pathologies received TEVAR with surgeon modified fenestrated stent grafts. The technical success rate was 98.6% (n = 506). In total, 626 fenestrations were created to revascularise 684 branch arteries of the aortic arch. There were 13 deaths and 15 re-interventions within 30 days of the operation. The estimated clinical success rate at 30 days was 94.4% (95% confidence interval [CI] 92.4 - 96.4), the estimated survival at 30 days was 97.5% (95% CI 96.1 - 98.9), and the estimated freedom from re-intervention at 30 days was 97.1% (95% CI 95.7 - 98.5). The median follow up was 27 (interquartile range 13 - 31) months. During follow up, there were five aortic related deaths, three non-aortic related deaths, and four deaths of unknown cause. Eighteen patients underwent re-intervention. The estimated clinical success rate at 24 months was 88.2% (95% CI 85.5 - 91.0), the estimated survival at 24 months was 94.9% (95% CI 92.7 - 97.1), and the estimated freedom from re-intervention at 24 months was 93.1% (95% CI 91.0 - 95.3). In total, 18 cases of stroke were recorded, including 12 within 30 days and six during follow up; six cases of retrograde type A aortic dissection were recorded, including five within 30 days and one during the follow up. CONCLUSION: TEVAR with surgeon modified fenestrated stent grafts for the treatment of aortic arch pathologies provides acceptable outcomes. Further follow up is required to confirm the benefits of this approach.

Translation of Tudor-SN, a novel terminal oligo-pyrimidine (TOP) mRNA, is regulated by the mTORC1 pathway in cardiomyocytes.

The mechanisms that regulate cell-cycle arrest of cardiomyocytes during heart development are largely unknown. We have previously identified Tudor staphylococcal nuclease (Tudor-SN) as a cell-cycle regulator and have shown that its expression level was closely related to cell-proliferation capacity. Herein, we found that Tudor-SN was highly expressed in neonatal mouse myocardia, but it was lowly expressed in that of adults. Using Data Base of Transcription Start Sites (DBTSS), we revealed that Tudor-SN was a terminal oligo-pyrimidine (TOP) mRNA. We further confirmed that the translational efficiency of Tudor-SN mRNA was controlled by the mammalian target of rapamycin complex 1 (mTORC1) pathway, as revealed via inhibition of activated mTORC1 in primary neonatal mouse cardiomyocytes and activation of silenced mTORC1 in adult mouse myocardia; additionally, this result was recapitulated in H9c2 cells. We also demonstrated that the downregulation of Tudor-SN in adult myocardia was due to inactivation of the mTORC1 pathway to ensure that heart growth was in proportion to that of the rest of the body. Moreover, we revealed that Tudor-SN participated in the mTORC1-mediated regulation of cardiomyocytic proliferation, which further elucidated the correlation between Tudor-SN and the mTORC1 pathway. Taken together, our findings suggest that the translational efficiency of Tudor-SN is regulated by the mTORC1 pathway in myocardia and that Tudor-SN is involved in mTORC1-mediated regulation of cardiomyocytic proliferation and cardiac development.

Changes in Coagulation and Fibrinolysis Systems During the Perioperative Period of Acute Type A Aortic Dissection.

BACKGROUND: Acute type A aortic dissection (ATAAD) has a high risk of perioperative bleeding and often requires extensive blood product infusions. Analysis of the changes in coagulation and fibrinolysis is both helpful for proper treatment and an improved prognosis. The present study investigated the changes in the coagulation and fibrinolysis systems during the perioperative period of ATAAD. METHODS: Twenty-two patients with ATAAD were included in this study. After diagnosis, all patients underwent ascending aorta replacement, aortic arch replacement, and implantation of a special stented endovascular graft. The control group included 25 patients undergoing elective aortic surgery. Baseline preoperative, intraoperative, and postoperative data were collected in both groups. Venous blood samples of all subjects were collected at five time points, after admission (T1), before surgery (T2), after protamine reversal (T3), postoperative 6 h (T4), and postoperative 24 h (T5), measuring the concentrations of platelet factor 4 (PF4), prothrombin fragment 1 + 2 (F1+2), tissue factor (TF), tissue factor pathway inhibitor (TFPI), plasminogen activator (PA), plasminogen activator inhibitor-1 (PAI-1) and thrombin antithrombin complex (TAT) by enzyme-linked immunosorbent assays (ELISAs). RESULTS: The average age of the ATAAD group was 49.9±12.5 years old, while that of the control group was 57.0±12.1 years old. There were more patients with a smoking history, and the cardiopulmonary bypass time, aortic cross-clamp time, and preoperative left ventricular ejection fraction were higher in the ATAAD group than in the control group (P < 0.05). Additionally, preoperative fibrin degradation products (FDP) and preoperative D-dimer were higher in the ATAAD group than in the control group (P < 0.05). However, time from onset to operation, intraoperative core temperature, preoperative B-type natriuretic peptide (BNP), and left ventricular end-diastolic diameter in the ATAAD group were lower than those in the control group (P < 0.05). In contrast, however, the proportion of abnormal bicuspid aortic valves in the control group was higher (P < 0.05). TF in the ATAAD group was significantly higher at T1 (7.9±3.7 ng/mL versus 0.9±0.7 ng/mL, P < 0.05). The TFPI in the ATAAD group was higher than that in the control group at T1 and T2 (P < 0.05). Additionally, PA in the ATAAD group was higher than that in the control group at T1, T2, T3, and T5 (P < 0.05), while PA in the control group was significantly higher at T3 than at T1 (P < 0.05). There was no significant difference in PAI-1 between the two groups before surgery (P > 0.05). Nevertheless, both groups reached their peak value at T3. The platelet count and fibrinogen (FBG) in the ATAAD group decreased significantly from T1 to T2 and continued to decrease after cardiopulmonary bypass. F1+2 and TAT in the ATAAD group were higher than in the control group (P < 0.05); however, they peaked at T3. The PF4 in the ATAAD group slightly increased at T1, while PF4 at T3 was significantly higher than at T1 (P < 0.05). CONCLUSION: The changes in coagulation and fibrinolysis in the ATAAD group before surgery were very significant, which caused a large amount of fibrinogen and platelet consumption. Cardiopulmonary bypass (CPB) and a lower intraoperative core temperature exacerbated the coagulation and fibrinolysis disorder, and the pro-coagulant function of the platelets was activated after surgery. Maintaining the normal concentration of fibrinogen was helpful to correct the coagulation function disorder.

Gene expression profiling analysis to investigate the role of remote ischemic postconditioning in ischemia-reperfusion injury in rats.

BACKGROUND: Blood flow restoration is a definitive therapy for salvaging the myocardium following ischemic injury. Nevertheless, the sudden restoration of blood flow to the ischemic myocardium can induce ischemia-reperfusion injury (IRI). RESULTS: Herein, we investigated the cardioprotective effect of remote ischemic postconditioning (RPostC) through our in vivo rat model of myocardial IRI. The study included three groups: the control group, the IRI group, and the IRI + RPostC group. Ischemia-reperfusion treatment led to an increase in the myocardial infarction area, which was inhibited by RPostC. In contrast to that in the control group, the myocardial apoptosis level was enhanced in the IRI group, whereas RPostC treatment decreased IRI-induced cellular apoptosis. Affymetrix Rat Gene 2.0 ST chip data identified a total of 265 upregulated genes and 267 downregulated genes between the IRI and IRI + RPostC groups. A group of differentially expressed noncoding RNAs (ncRNAs), such as MTA_TC0600002772.mm, MTA_TC1300002394.mm, U7 small nuclear RNA (Rnu7) and RGD7543256_1, were identified. Gene Ontology (GO) enrichment analysis indicated that the positive regulation of some molecular functions, such as GTPase activity, GTP binding, cyclic-nucleotide phosphodiesterase activity and cytokine activity, may contribute to the cardioprotective role of RPostC. Moreover, pathway enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) suggested the potential implication of the TNF signaling pathway and Toll-like receptor signaling pathway. Global signal transduction network analysis, co-expression network analysis and quantitative real-time polymerase chain reaction analysis further identified several core genes, including Pdgfra, Stat1, Lifr and Stfa3. CONCLUSION: Remote ischemic postconditioning treatment can decrease IRI-mediated myocardial apoptosis by regulating multiple processes and pathways, such as GTPase activity, cytokine activity, and the TNF and Toll-like receptor signaling pathways. The potential role of the above ncRNAs and core genes in IRI-induced cardiac damage merits further study as well.

Phosphorylation of Tudor-SN, a novel substrate of JNK, is involved in the efficient recruitment of Tudor-SN into stress granules.

Posttranslational modifications of certain stress granule (SG) proteins are closely related to the assembly of SGs, a type of cytoplasmic foci structure. Our previous studies revealed that the Tudor staphylococcal nuclease (Tudor-SN) protein participates in the formation of SGs. However, the functional significance of potential Tudor-SN modifications during stress has not been reported. In this study, we demonstrated that the Tudor-SN protein was phosphorylated at threonine 103 (T103) upon stimulation with arsenite. In addition, c-Jun N-terminal kinase (JNK) was found to be responsible for Tudor-SN phosphorylation at the T103 site. We further illustrated that either a T103A mutation or the suppression of phosphorylation of T103 by the JNK inhibitor SP600125 inhibited the efficient recruitment of Tudor-SN into SGs. In addition, the T103A mutation could affect the physical binding of Tudor-SN with the G3BP (Ras-GAP SH3 domain-binding protein) protein but not with the HuR (Hu antigen R) protein and AGTR1-3'UTR (3'-untranslated region of angiotensin II receptor, type 1) mRNA cargo. These data suggested that JNK-enhanced Tudor-SN phosphorylation promotes the interaction between Tudor-SN and G3BP and facilitates the efficient recruitment of Tudor-SN into SGs under conditions of sodium arsenite-induced oxidative stress. This finding provides novel insights into the physiological function of Tudor-SN modification.

Long Period and High Level of D-Dimer after Coronary Artery Bypass Grafting Surgery.

Hyper-coagulation after off-pump coronary artery bypass grafting (OPCAB) is one of the main reasons for graft thrombosis. D-dimer is closely linked to the activation of coagulation. Few studies have reported the variation range and long-term abnormal coagulation after OPCAB in the Chinese population. Our study aimed to determine the characteristics and value of D-dimer after OPCAB.In this prospective study, 265 patients who underwent OPCAB for the first time were recruited from 2011 to 2012. The D-dimer level of the patients was tested before surgery and on the 1st, 4th, and 14th day, and 1st, 2nd, and 3rd month after surgery. Clinical data in the perioperative period and during the one-year follow-up period were recorded.D-dimer level increased from day 4 after OPCAB ([1321.9 ± 36.4] µg/L), peaked at 1 month ([2839.7 ± 101.4] µg/L), and decreased to the baseline ([370.3 ± 260.2] µg/L) 3 months after surgery. No death occurred, but 25 (10%) patients suffered recurrent angina in the one-year follow-up. They had significantly higher D-dimer level at one month after OPCAB than those of patients who did not suffer from angina. Preoperative ejection fraction <50% and D-dimer level >2915 µg/L at one month after surgery were significantly associated the recurrent angina.After OPCAB, patients have a higher level of D-dimer. And this lasts for a long period (about 3 months). It may reflect a certain degree of hypercoagulable and hyperfibrinolytic state after OPCAB.

Tudor staphylococcal nuclease (Tudor-SN), a novel regulator facilitating G1/S phase transition, acting as a co-activator of E2F-1 in cell cycle regulation.

Tudor staphylococcal nuclease (Tudor-SN) is a multifunctional protein implicated in a variety of cellular processes. In the present study, we identified Tudor-SN as a novel regulator in cell cycle. Tudor-SN was abundant in proliferating cells whereas barely expressed in terminally differentiated cells. Functional analysis indicated that ectopic overexpression of Tudor-SN promoted the G1/S transition, whereas knockdown of Tudor-SN caused G1 arrest. Moreover, the live-cell time-lapse experiment demonstrated that the cell cycle of MEF(-/-) (knock-out of Tudor-SN in mouse embryonic fibroblasts) was prolonged compared with wild-type MEF(+/+). We noticed that Tudor-SN was constantly expressed in every cell cycle phase, but was highly phosphorylated in the G1/S border. Further study revealed that Tudor-SN was a potential substrate of Cdk2/4/6, supportively, we found the physical interaction of endogenous Tudor-SN with Cdk4/6 in G1 and the G1/S border, and with Cdk2 in the G1/S border and S phase. In addition, roscovitine (Cdk1/2/5 inhibitor) or CINK4 (Cdk4/6 inhibitor) could inhibit the phosphorylation of Tudor-SN, whereas ectopic overexpression of Cdk2/4/6 increased the Tudor-SN phosphorylation. The underlying molecular mechanisms indicated that Tudor-SN could physically interact with E2F-1 in vivo, and could enhance the physical association of E2F-1 with GCN5 (a cofactor of E2F-1, which possesses histone acetyltransferase activity), and promote the binding ability of E2F-1 to the promoter region of its target genes CYCLIN A and E2F-1, and as a result, facilitate the gene transcriptional activation. Taken together, Tudor-SN is identified as a novel co-activator of E2F-1, which could facilitate E2F-1-mediated gene transcriptional activation of target genes, which play essential roles in G1/S transition.

Tudor-SN, a novel coactivator of peroxisome proliferator-activated receptor γ protein, is essential for adipogenesis.

Adipogenesis, in which mesenchymal precursor cells differentiate into mature adipocytes, is a well orchestrated process. In the present study we identified Tudor-SN as a novel co-activator of the transcription factor peroxisome proliferator-activated receptor γ (PPARγ). We provide the first evidence that Tudor-SN and PPARγ exist in the same complex. Both are up-regulated by the early factor C/EBPß during adipogenesis and significantly influence the regulation of PPARγ target genes in both 3T3-L1 pre-adipocyte and mouse embryonic fibroblasts (MEF) upon exposure to a mixture of hormonal mixture. Moreover, aP2-PPARγ response element (PPRE) interacts with both PPARγ and Tudor-SN, and the gene transcriptional activation of PPRE-luc is enhanced by ectopic expression of Tudor-SN. Deletion of Tudor-SN protein (MEF-KO) affects but does not completely abolish the association of PPARγ and aP2-PPRE. Loss-of-function studies further verified that Tudor-SN is required for adipogenesis, as deletion of Tudor-SN (MEF-KO) impairs dexamethasone, 3-isobutyl-1-methylxanthine, and insulin (DMI)-induced adipocyte differentiation and the expression of PPARγ target genes, such as aP2 and adipsin. Furthermore, H3 acetylation levels were lower in MEF-KO than MEF-WT. Both HDAC1 and HDAC3 are stably associated with PPARγ in MEF-KO, whereas only a small amount of association was observed in MEF-WT after 5 days of treatment during adipogenesis. PPARγ requires various co-activators or co-repressors, which may dynamically associate with and regulate the higher order chromatin remodeling of the promoter region of PPARγ-bound target genes; Tudor-SN is likely one of these co-activators.

Staging reinterventions for remodeling of residual aortic dissection: a single-center retrospective study.

Objective: Inadequate remodeling of residual aortic dissection (RAD) following repair of Stanford A or B aortic dissections has been identified as a significant predictor of patient mortality. This study evaluates the short- to mid-term outcomes of staged reinterventions for RAD at a single center with prospective follow-up. Methods: Data were retrospectively collected from patients with RAD who underwent staged reinterventions or received none-surgery treatment in the Cardiovascular Surgery Department of our hospital between July 2019 and December 2021. The cohort included 54 patients with residual distal aortic dissection post-primary surgery, comprising 28 who underwent open surgery and 26 who received thoracic endovascular aortic repair (TEVAR). Patients were divided into two groups: those who underwent staged stent interventions for distal dissection [staged reintervention (SR) group] and those who did not undergo surgery (non-surgery group). For the SR group, second or third staged stent interventions were performed. The study assessed distal remodeling of aortic dissection between the groups, focusing on endpoints such as mortality (both general and aortic-specific), occurrences of visceral branch occlusion, necessity for further interventions, and significant adverse events. Morphological changes were analyzed to determine the therapeutic impact. Results: The study encompassed 54 participants, with 33 in the SR group and 21 in the non-surgical control group. Baseline demographics and clinical characteristics were statistically comparable across both groups. During an average follow-up of 31.5 ± 7.0 months, aortic-related mortality was 0% in both groups; all-cause mortality was 3% (one case) and 5% (one case) in the SR and control groups, respectively, with no statistically significant difference noted. In the SR group, a single patient experienced complications, including renal artery thrombosis, leading to diminished blood flow. An increased true lumen (TL) area and a decreased false lumen area at various aortic planes were observed in the SR group compared to the control group. Conclusion: The staged reintervention strategy for treating RAD is safe and provides promising early results.

Application of the radial artery after angiography in patients undergoing total arterial coronary revascularization.

OBJECTIVE: There is growing evidence supporting the utilization of the radial artery as a secondary arterial graft in coronary artery bypass grafting (CABG) surgery. However, debates continue over the recovery period of the radial artery following angiography. This study aims to evaluate the clinical outcomes and experiences related to the use of the radial artery post-angiography in total arterial coronary revascularization. METHODS: A retrospective analysis was performed on data from patients who underwent total arterial CABG surgery at the University of Hong Kong Shenzhen Hospital from July 1, 2020, to September 30, 2022. Preoperative assessments included ultrasound evaluations of radial artery blood flow, diameter, intimal integrity, and the Allen test. Additionally, pathological examinations of the distal radial artery and coronary artery CT angiography were conducted, along with postoperative follow-up to assess the safety and efficacy of using the radial artery in patients undergoing total arterial CABG. RESULTS: A total of 117 patients, compromising 102 males and 15 females with an average age of 60.0 ± 10.0 years, underwent total arterial CABG. The internal mammary artery was used in situ in 108 cases, while in 4 cases, it was grafted to the ascending aorta due to length limitations. Bilateral radial arteries were utilized in 88 patients, and bilateral internal mammary arteries in 4 patients. Anastomoses of the proximal radial arteries to the proximal ascending aorta included 42 cases using distal T-anastomosis and 4 using sequential grafts. The interval between bypass surgery and coronary angiography ranged from 7 to 14 days. Pathological examination revealed intact intima and continuous elastic membranes with no significant inflammatory infiltration or hyperplastic lumen stenosis in the radial arteries. There were no hospital deaths, 3 cases of perioperative cerebral infarction, 1 secondary thoracotomy for hemorrhage control, 21 instances of intra-aortic balloon pump (IABP) assistance, and 2 cases of poor wound healing that improved following debridement. CT angiography performed 2 weeks post-surgery showed no internal mammary artery occlusions, but 4 radial artery occlusions were noted. CONCLUSION: Ultrasound may be used within 2 weeks post-angiography to assess the recovery of the radial artery in some patients. Radial arteries with intact intima may be considered in conjunction with the internal mammary artery for total arterial coronary CABG. However, long-term outcomes of these grafts require further validation through larger prospective studies.

Polymorphisms and high on-aspirin platelet reactivity after off-pump coronary artery bypass grafting.

OBJECTIVES: High on-aspirin residual platelet reactivity (RPR) after coronary artery bypass grafting (CABG) is a transient phenomenon with important implications for graft patency. This study was designed to determine the role of polymorphisms [TBXA2R (T924C), GPIIIa (Pl(A1/A2)), P2Y1 (A1622G), and GP1Bα (C1018T)] on RPR in Chinese patients undergoing off-pump CABG (OPCAB). METHODS: Of 420 patients recruited to this study, 210 patients underwent primary OPCAB and 210 controls with ischemic heart disease received optimal medical therapy. Arachidonic acid-induced platelet aggregation and urinary 11-dehydro thromboxane B2 were measured at baseline and following aspirin administration on days 1, 4, 10, and on 6th month. Four polymorphisms were identified [TBXA2R (T924C), P2Y1 (A1622G), Pl(A1/A2) and GP1Bα (C1018T)]. RESULTS: On the first post-operative day, 62 patients (29.5%) were with high RPR and 148 (70.5%) were with low RPR. Of the former, 33 (15.7%), 10 (4.6%), and 0 (0%) patients remained with high RPR on days 4, 10, and on 6 month, respectively. No individuals with high RPR was found in controls. Logistic regression identified TBXA2R-924TT (OR = 4.5; 95% CI, 1.8-11.1) and body mass index > 27 kg/m(2) (OR = 2.73; 95% CI, 1.1-7.0) as independent risk factors for high on-aspirin RPR. CONCLUSIONS: High on-aspirin RPR after OPCAB is associated with genetic polymorphism TBXA2R-924TT and obesity.

[Overexpression of connexin 40 (Cx40) inhibits the proliferation of H9c2 cardiomyocytes in rats by cell cycle arrest].

Objective To establish a stable strain of H9c2 cardiomyocytes overexpressing Cx40 and preliminarily investigate the effect of lentiviral vector-mediated Cx40 protein overexpression on the proliferation of H9c2 cells and its related mechanisms. Methods The Cx40 gene fragment was cloned from H9c2 cells by PCR and linked with lentivirus vector pLVX-IRES-Puro to obtain the recombinant plasmid pLVX-Flag-Cx40. Recombinant lentiviral particles carrying Flag-Cx40 were obtained by cotransfection with packaging plasmids into HEK293T cells. A stable expression strain (H9c2-Flag-Cx40 cell) was screened from infected H9c2 cells by purinomycin. The expression of Cx40 protein was detected by Western blot analysis, and the effect of Cx40 on H9c2 cells proliferation was determined by CCK-8 assay; cell cycle changes were measured by flow cytometry; the expression of the cell cycle protein cyclin D1 was detected by qRT-PCR and Western blot analysis. Co-immunoprecipitation (Co-IP) immunoprecipitation and Western blot analysis were used to identify the binding of Cx40 and Yes associated protein (YAP) in H9c2 cells; cytoplasmic and cytosolic proteins were isolated to detect the effect of Cx40 on the localization of YAP using Western blot analysis. Results Sequencing results showed that the recombinant pLVX-Flag-Cx40 expression vector was successfully established. A stable transfected cell line containing recombinant Flag-Cx40 lentivirus (H9c2-Flag-Cx40 cell) was successfully constructed from H9c2 cells. Compared with the control group, overexpression of Cx40 significantly reduced the proliferation of H9c2 cells, arrested the cell cycle at G0/G1 and reduced cyclin D1 expression. A significant increase in YAP expression was observed in the cytoplasm of the H9c2-Flag-Cx40 stable cell line, while the expression in the nucleus was significantly reduced. Cx40 bound to YAP in the cytoplasm and prevented it from entering the nucleus to play the role of transcriptional coactivation. Conclusion Overexpression of Cx40 induces cell-cycle arrest at G0/G1 phase and inhibits the proliferation in H9c2 cells.

Efficacy of endovascular repair in the treatment of retrograde ascending aortic intramural haematoma.

BACKGROUND: The current treatment for retrograde ascending aortic intramural hematoma (RAIMH) remains challenging. This study aims to summarize the short-term results of endovascular repair in the treatment of retrograde ascending aortic intramural hematoma. METHODS: Between June 2019 and June 2021, 21 patients (16 males and 5 females) with a retrograde ascending aortic intramural hematoma, aged 53 ± 14years, received an endovascular repair in our hospital. All cases involved an ascending aortic or aortic arch intramural hematoma. 15 patients had an ulcer on the descending aorta combined with an intramural hematoma in the ascending aorta and 6 patients had typical dissection changes on the descending aorta combined with an intramural hematoma in the ascending aorta. All patients had a successful endovascular stent-graft repair, with 10 cases operated on in the acute phase (<14 days) and 11 cases in the chronic phase (14-35 days). RESULTS: A single-branched aortic stent graft system was implanted in 10 cases, a straight stent in 2 cases, and a fenestrated stent in 9 cases. All surgeries were technically successful. One of the patients developed a new rupture 2 weeks after surgery and was converted to a total arch replacement. No perioperative stroke, paraplegia, stent fracture or displacement, limb or abdominal organ ischemia occurred. The intramural hematomas started being absorbed on CT angiography images before discharge. There was no incidence of postoperative 30-day mortality, and the intramural hematomas in the ascending aorta and aortic arch were fully or partly absorbed. CONCLUSION: Endovascular repair of retrograde ascending aortic intramural hematoma was shown to be safe and effective, and correlated with favorable short-term results.

[Application of radial artery in total arterial coronary revascularization in elderly patients].

OBJECTIVE: To summarize the application experience and clinical effect of radial artery in total arterial coronary revascularization (TAR) in elderly patients. METHODS: Retrospectively analyzed the clinical data of patients who underwent TAR at the University of Hong Kong Shenzhen Hospital from July 1, 2020 to May 30, 2022. Patients were divided into ≥ 65-year-old group and < 65-year-old group according to age. The radial artery blood flow, diameter, intimal integrity and Allen test were evaluated by ultrasound before operation. The distal ends of radial artery were collected for pathological examination during operation. Coronary artery CT angiography (CTA) was examined postoperatively and follow up. The safety and reliability of ultrasonic assessment of radial artery and application of radial artery in elderly patients with TAR were summarized and analyzed. RESULTS: A total of 101 patients received TAR, including 35 cases aged ≥ 65 years old, 66 cases aged < 65 years old; 78 cases used bilateral radial arteries, and 23 cases used unilateral radial arteries. 4 cases of bilateral internal mammary arteries. All the proximal ends of the radial artery were anastomosed to the proximal end of the ascending aorta, 34 cases were performed of "Y" grafts, and 4 cases were sequential anastomoses. There was no in-hospital death and perioperative cardiovascular events. Perioperative cerebral infarction occurred in 3 patients. 1 patients was reoperated for bleeding. Intra-aortic balloon pump (IABP) assistance was used in 21 patients. Poor wound healing occurred in 2 cases and healed well after debridement. Follow-up of 2 to 20 months after discharge showed no internal mammary artery occlusion and 4 radial artery occlusions; no major adverse cardiovascular and cerebrovascular event (MACCE) occurred, and the survival rate was 100%. There was no significant difference in the above perioperative complications and follow-up endpoints between the two age groups. CONCLUSIONS: By adjusting the order of bypass anastomosis and optimizing the preoperative evaluation method, radial artery combined with internal mammary artery can obtain better outcome early in TAR, and can be safely and reliably applied to elderly patients.

Investigation into the role of Stmn2 in vascular smooth muscle phenotype transformation during vascular injury via RNA sequencing and experimental validation.

This study examined the effects of Stmn2 on phenotype transformation of vascular smooth muscle in vascular injury via RNA sequencing and experimental validation. Total RNA was extracted for RNA sequencing after 1, 3 and 5 days of injury to screen the differentially expressed genes (DEGs). Western blot was used to detect the protein expression of Stmn2 and its associated targets. The morphological changes of carotid arteries in rats were examined by hematoxylin and eosin (H&E) staining. The expression of vascular smooth muscle cell (VSMC) phenotype markers smooth muscle alpha-actin (α-SMA), vimentin and OPN were detected by immunohistochemistry. DEGs were related to the extracellular matrix and other cell components outside the plasma membrane. They were associated with protein binding, cytoskeleton protein binding, signal receptor binding and other molecular functions, actin cytoskeleton regulation and other Kyoto Encyclopedia of Genes and Genomes pathways. Stmn2 was identified as the hub gene of actin cytoskeleton pathway and vascular disease, and its expression followed the trend of decreasing initially and increasing afterwards during the progress of vascular injury. Western blot assay showed that the expression of Stmn2 and Tubulin decreased immediately after vascular injury; Stmn2 overexpression significantly up-regulated the expression of osteopontin and α-SMA and vimentin in VSMCs. The results of morphology analysis and immunostaining also showed that Stmn2 overexpression promoted the intima thickening and enhanced the proliferating cell nuclear antigen expression in the injured vascular tissues. In conclusion, our results implied that Stmn2 may play a potential role in vascular injury, which may be associated with VSMC phenotype transformation. Further studies are warranted to determine detailed molecular mechanisms of Stmn2 in vascular injury.

Postconditioning inhibits myocardial apoptosis during prolonged reperfusion via a JAK2-STAT3-Bcl-2 pathway.

BACKGROUND: Postconditioning (PostC) inhibits myocardial apoptosis after ischemia-reperfusion (I/R) injury. The JAK2-STAT3 pathway has anti-apoptotic effects and plays an essential role in the late protection of preconditioning. Our aim was to investigate the anti-apoptotic effect of PostC after prolonged reperfusion and the role of the JAK2-STAT3 pathway in the anti-apoptotic effect of PostC. METHODS: Wistar rats were subjected to 30 minutes ischemia and 2 or 24 hours (h) reperfusion, with or without PostC (three cycles of 10 seconds reperfusion and 10 seconds reocclusion at the onset of reperfusion). Separate groups of rats were treated with a JAK2 inhibitor (AG490) or a PI3K inhibitor (wortmannin) 5 minutes before PostC. Immunohistochemistry was used to analyze Bcl-2 protein levels after reperfusion. mRNA levels of Bcl-2 were detected by qRT-PCR. TTC staining was used to detect myocardial infarction size. Myocardial apoptosis was evaluated by TUNEL staining. Western-blot was used to detect p-STAT3 and p-Akt levels after reperfusion. RESULTS: There was more myocardial apoptosis at 24 h vs 2 h after reperfusion in all groups. PostC significantly reduced myocardial apoptosis and elevated Bcl-2 levels at both 2 and 24 hours after reperfusion. PostC increased p-STAT3 and p-Akt levels after reperfusion. Administration of AG490 reduced p-STAT3 and p-Akt levels and attenuated the anti-apoptotic effect of PostC. Wortmannin also reduced p-Akt levels and attenuated the anti-apoptotic effect of PostC but had no effect on p-STAT3 levels. AG490 abrogated the up-regulation of Bcl-2 by PostC. CONCLUSION: PostC may reduce myocardial apoptosis during prolonged reperfusion via a JAK2-STAT3-Bcl-2 pathway. As a downstream target of JAK2 signaling, activation of PI3K/Akt pathway may be necessary in the protection of PostC.