Gramine improves sepsis-induced myocardial dysfunction by binding to NF-κB p105 and inhibiting its ubiquitination.

BACKGROUND: Sepsis and its associated heart failure are among the leading causes of death. Gramine, a natural indole alkaloid, can be extracted from a wide variety of raw plants, and it exhibits therapeutic potential in pathological cardiac hypertrophy. However, the effect of gramine on inflammatory cardiomyopathy, particularly sepsis-induced myocardial injury, remains an unexplored area. PURPOSE: To determine the role of gramine in sepsis-induced myocardial dysfunction and explore its underlying mechanism. STUDY DESIGN AND METHODS: In mice, sepsis was established by intraperitoneally injecting lipopolysaccharide (LPS, 10 mg/kg). Subsequently, the effects of gramine administration (50 or 100 mg/kg) on LPS-triggered cardiac dysfunction in mice were investigated. For in vitro studies, isolated primary cardiomyocytes were used to assess the effect of gramine (25 or 50 µM) on LPS-induced apoptosis and inflammation. Additionally, molecular docking, co-immunoprecipitation and ubiquitination analyzes were conducted to explore the underlying mechanisms. RESULTS: Gramine visibly ameliorated sepsis-induced cardiac dysfunction, inflammatory response, and mortality in vivo. Moreover, it significantly alleviated LPS-induced apoptotic and inflammatory responses in vitro. Furthermore, target prediction for gramine using the SuperPred website indicated that the nuclear factor NF-κB p105 subunit was one of the molecules ranked in priority order with a high model accuracy and a high probability score. Molecular docking studies demonstrated that gramine effectively docked to the death domain of NF-κB p105. Mechanistic studies revealed that gramine suppressed the processing of NF-κB p105 to p50 by inhibiting NF-κB p105 ubiquitination. Additionally, the protective effect of gramine on cardiac injury was almost abolished by overexpressing NF-κB p105. CONCLUSION: Gramine is a promising bioactive small molecule for treating sepsis-induced myocardial dysfunction, which acts by docking to NF-κB p105 and inhibiting NF-κB p105 ubiquitination, thus preventing its processing to NF-κB p50. Therefore, gramine holds potential as a clinical drug for treating myocardial depression during sepsis.

Mesophilic Argonaute-based isothermal detection of SARS-CoV-2.

Coronavirus disease (COVID-19), caused by SARS-CoV-2 infection and its mutations, has spread rapidly all over the world and still requires sensitive detection to distinguish mutations. CRISPR-based diagnosis has been regarded as a next-generation detection method; however, it has some limitations, such as the need for specific recognition sequences and multiple enzymes for multiplex detection. Therefore, research on the exploration and development of novel nucleases helps to promote specific and sensitive diagnoses. Prokaryotic Argonaute (Ago) proteins exert directed nuclease activity that can target any sequence. Recently, thermophilic Agos have been developed as new detection techniques achieving multiplexity for multiple targets using a single enzyme, as well as accurate recognition of single-base differential sequences. In this study, to overcome the requirement for high reaction temperature of thermophilic Ago-based methods, we expanded the mining of mesophilic Agos to achieve CRISPR-like isothermal detection, named mesophilic Ago-based isothermal detection method (MAIDEN). The principle of MAIDEN uses mesophilic Ago cleavage combined with reverse transcription, which can provide single-strand DNA as a substrate and allow cleavage of fluorescence probes to sense SARS-CoV-2 at moderate temperature. We first mined and optimized the mesophilic Ago and the fluorescence reporter system and then selected a compatible reverse transcription reaction. Furthermore, we optimized MAIDEN into a one-step reaction that can detect SARS-CoV-2 RNA at the nanomolar concentration at a constant temperature of 42°C within 60 min. Therefore, MAIDEN shows advantageous portability and easy-to-implement operation, avoiding the possibility of open-lid contamination. Our study was the first attempt to demonstrate that mesophilic Agos can be harnessed as diagnostic tools, and MAIDEN was easily extended to detect other pathogens in a rapid and efficient manner.

Cardiac device implant wound closure with a novel low-density suture spacing single layer method.

BACKGROUND: To establish a novel time-saving and safe suture method for cardiac implantable electronic device (CIED) implantation. METHODS: From January 2017 to April 2020, a total of 1317 patients scheduled for CIED procedure were consecutively enrolled in this study. Wound closure of all patients were prospectively assigned either to low-density suture spacing single layer suture group (single-layer group) or traditional two layer suture group (two-layer group). The effects of two closure methods on wound healing and pocket related complications were compared. RESULTS: There were no significant differences in age, gender, BMI, comorbid diseases (diabetes, hypertension, coronary heart disease, and chronic kidney disease), and antiplatelet or anticoagulant drug use between the two groups. The number of suture stitches in the single-layer group was significantly less than that in the two-layer group [3.03(3-4) vs. 7.17(7-10), p < .001], the suture time in the single-layer group was significantly shorter than that in the two-layer group [190.57(167-256) s vs. 493.36(452-655) s, p < .001], and the incidence of clinically significant hematoma in the single-layer group was comparable to that in the two-layer group (0.7% vs. 0.3%, p = .742). Additionally, there were no significant differences in the incidence of pocket infection, dehiscence and keloid between the two groups. CONCLUSION: Novel single-layer suture with low-density suture spacing is feasible and associated with a low incidence of wound dehiscence or infection for CIED implantation.

Circulating primary bile acid is correlated with structural remodeling in atrial fibrillation.

BACKGROUND: Circulating primary bile acid was involved in the regulation of cardiac ionic channel currents and ventricular myocyte apoptosis, but it was unknown whether or not it played a role in structural remodeling of AF. This study was aimed to testify the hypothesis that elevated chenodeoxycholic acid (CDCA) concentration correlated with left atrial low voltage area (LVA) and could induce apoptosis of atrial myocytes in AF. METHODS AND RESULTS: Serum concentrations of 12 types of bile acids were determined in patients with paroxysmal (n = 21), persistent AF (n = 20), and type A pre-excitation and paroxysmal supraventricular tachycardia (PSVT) (n = 19) and were correlated with LVA in AF, which was obtained by electroanatomical mapping during ablation. Additionally, the impact of CDCA incubation on apoptosis of mouse atrial myocytes was evaluated. Serum levels of CDCA and cholic acid were significantly higher in AF than in PSVT. CDCA serum concentration was significantly higher in persistent AF than in paroxysmal AF. CDCA serum level was positively correlated with the size (r = 0.78, P < 0.05) and proportion of LVA (r = 0.89, P < 0.05) in AF patients. CDCA (75 µM, 100 µM) promoted atrial myocyte apoptosis in a concentration-dependent manner. CONCLUSIONS: The higher circulating level of CDCA in AF than in PSVT, positive correlation of CDCA with LVA in AF, and incubation dose-dependent increase of mouse atrial myocyte apoptosis indicated that CDCA might play a significant role in the progress of structural remodeling of AF.

Novel Protective Role for Ubiquitin-Specific Protease 18 in Pathological Cardiac Remodeling.

Ubiquitin-specific protease 18 (USP18), a USP family member, is involved in antiviral activity and cancer inhibition. Although USP18 is expressed in heart, the role of USP18 in the heart and in cardiac diseases remains unknown. Here, we show that USP18 expression is elevated in both human dilated hearts and hypertrophic murine models. Cardiomyocyte-specific overexpression of USP18 in mice significantly blunted cardiac remodeling as evidenced by mitigated myocardial hypertrophy, fibrosis, ventricular dilation, and preserved ejection function, whereas USP18-deficient mice displayed exacerbated cardiac remodeling under the same pathological stimuli. Similar results were observed for in vitro angiotensin II-induced neonatal rat cardiomyocyte hypertrophy. The antihypertrophic effects of USP18 under hypertrophic stimuli were associated with the blockage of the transforming growth factor-ß-activated kinase 1-p38/c-Jun N-terminal kinase 1/2 signaling cascade. Blocking transforming growth factor-ß-activated kinase 1-p38/c-Jun N-terminal kinase 1/2 signaling with a pharmacological inhibitor (5Z-7-oxozeaenol) greatly reversed the detrimental effects observed in USP18-knockout mice subjected to aortic banding. Our data indicate that USP18 inhibits cardiac hypertrophy and postpones cardiac dysfunction during the remodeling process, which is dependent on its modulation of the transforming growth factor-ß-activated kinase 1-p38/c-Jun N-terminal kinase 1/2 signaling axis. Thus, USP18 is a potent therapeutic target for heart failure treatment.

Vitamin D receptor activation protects against myocardial reperfusion injury through inhibition of apoptosis and modulation of autophagy.

AIMS: To determine the roles of vitamin D receptor (VDR) in ischemia/reperfusion-induced myocardial injury and to investigate the underlying mechanisms involved. RESULTS: The endogenous VDR expression was detected in the mouse heart, and myocardial ischemia/reperfusion (MI/R) upregulated VDR expression. Activation of VDR by natural and synthetic agonists reduced myocardial infarct size and improved cardiac function. Mechanistically, VDR activation inhibited endoplasmic reticulum (ER) stress (determined by the reduction of CCAAT/enhancer-binding protein homologous protein expression and caspase-12 activation), attenuated mitochondrial impairment (determined by the decrease of mitochondrial cytochrome c release and caspase-9 activation), and reduced cardiomyocyte apoptosis. Furthermore, VDR activation significantly inhibited MI/R-induced autophagy dysfunction (determined by the inhibition of Beclin 1 over-activation, the reduction of autophagosomes, the LC3-II/LC3-I ratio, p62 protein abundance, and the restoration of autophagy flux). Moreover, VDR activation inhibited MI/R-induced oxidative stress through a metallothionein-dependent mechanism. The cardioprotective effects of VDR agonists mentioned earlier were impaired in the setting of cardiac-specific VDR silencing. In contrast, adenovirus-mediated cardiac VDR overexpression decreased myocardial infarct size and improved cardiac function through attenuating oxidative stress, and inhibiting apoptosis and autophagy dysfunction. INNOVATION AND CONCLUSION: Our data demonstrate that VDR is a novel endogenous self-defensive and cardioprotective receptor against MI/R injury, via mechanisms (at least in part) reducing oxidative stress, and inhibiting apoptosis and autophagy dysfunction-mediated cell death.

Liver X receptor agonist treatment attenuates cardiac dysfunction in type 2 diabetic db/db mice.

BACKGROUND: Liver X receptor (LXR) plays a critical regulatory role in metabolism and inflammation, and has been demonstrated to be involved in cardiovascular physiology/pathology. In the present study, we investigated the effect of GW3965, a potent LXR agonist, on diabetic cardiomyopathy (DCM) in type 2 diabetic db/db mice. METHODS AND RESULTS: Non-diabetic db/+ mice and diabetic db/db mice received either vehicle or LXR agonist GW3965 for 12 weeks. Systemic insulin resistance was evaluated by glucose tolerance test and homeostasis model assessment for insulin resistance. Endpoint cardiac function was assessed by echocardiography and catheterization. Ventricular tissue was collected for histology and gene/protein expression analysis. Untreated db/db diabetic mice exhibited diastolic dysfunction with adverse structural remodeling (including myocardial fibrosis and increased apoptosis). Treatment with GW3965 remarkably attenuated myocardial dysfunction and structural remodeling in diabetic db/db mice. Mechanistically, GW3965 restored Akt phosphorylation and inhibited MAP kinases phosphorylation, and reduced oxidative/nitrative stress and inflammation response in the diabetic myocardium. CONCLUSIONS: Our data demonstrate that GW3965 exerts a cardioprotective effect against DCM by (at least in part) attenuating insulin resistance, modulating Akt and MAP kinases pathways, and reducing oxidative/nitrative stress and inflammatory response. These findings strongly suggest that LXR agonist may have therapeutic potential in treating DCM.

[Farnesoid-X-receptor blockade reduces myocardial reperfusion injury in cholesterol-fed apolipoprotein E knockout mice].

OBJECTIVE: To investigate the effect of farnesoid-X-receptor (FXR) antagonist Z-guggulsterone in an in vivo high-fat fed apolipoprotein E knockout (ApoE(-/-)) mice model of myocardial ischemia/reperfusion (I/R). METHODS: Male ApoE(-/-) mice were randomly divided into three groups: standard ApoE(-/-) group (fed with standard mouse diet for 12 weeks before myocardial I/R procedure, n = 18), high-fat ApoE(-/-) group (fed with high-fat mouse diet for 12 weeks before myocardial I/R procedure, n = 22), and high-fat ApoE(-/-) + FXR antagonist group(fed with high-fat mouse diet for 12 weeks and received FXR antagonist Z-Guggulsterone 30 minutes before myocardial I/R procedure, n = 17). The expression of FXR was detected by real-time quantitative-PCR. Myocardial infarct size was determined by Evans blue/TTC double staining methods. Myocardial apoptosis was determined by in situ TUNEL technique. Markers of the mitochondrial-mediated apoptotic pathway (cytochrome c release, caspase-9 activity, and BAX and BCL-2 levels), endoplasmic reticulum stress apoptotic pathway (caspase-12 activity and CHOP level), and death receptor apoptotic pathway (caspase-8 activity, and Fas and FasL levels) were also measured. RESULT: FXR expression (3.7-fold higher, P < 0.01), myocardial infarct size [(62.1 ± 7.0)% vs. (33.8 ± 5.8)%, P < 0.01] and myocardial apoptosis index[ (36.8 ± 5.7)% vs. (17.2 ± 3.8)%, P < 0.01]were all significantly higher in high-fat ApoE(-/-) group than those in standard ApoE(-/-) group. Compared with high-fat ApoE(-/-) group, myocardial infarct size [(24.4 ± 4.7)% vs. (62.1 ± 7.0)%, P < 0.01] and myocardial apoptosis index [(13.8 ± 2.7)% vs. (36.8 ± 5.7)%, P < 0.01] were significantly reduced in high-fat ApoE(-/-) + FXR antagonist group. Moreover, levels of mitochondrial-mediated apoptotic pathway markers (cytochrome c release, caspase-9 activity, and BAX/BCL-2 levels) and endoplasmic reticulum stress apoptotic pathway markers (caspase-12 activity and CHOP level) were significantly lower in high-fat ApoE(-/-) + FXR antagonist group than those in high-fat ApoE(-/-) group (all P < 0.01). Levels of death receptor apoptotic pathway markers (caspase-8 activity, and Fas and FasL levels) were similar between high-fat ApoE(-/-) group and high-fat ApoE(-/-) + FXR antagonist group. CONCLUSION: FXR antagonist alleviates myocardial reperfusion injury in cholesterol-fed ApoE(-/-) mice via inhibition of the mitochondrial-mediated and endoplasmic-reticulum stress pathway.

Effect of statin pretreatment on myocardial perfusion in patients undergoing primary percutaneous coronary intervention: a systematic review and meta-analysis.

BACKGROUND: To achieve sufficient myocardial perfusion in ST-segment elevation myocardial infarction (STEMI) patients receiving primary percutaneous coronary intervention (PPCI), many adjunctive therapies have been proposed. Previous trials have reported variances in myocardial perfusion improvement for statin pretreatment, which made it inconvincible to confirm the beneficial effects of statins. Therefore, we performed a systematic review and meta-analysis to determine whether statin pretreatment was effective in improving myocardial perfusion. HYPOTHESIS: Statin pretreatment could improve myocardial perfusion in STEMI patients undergoing PPCI. METHODS: We searched the PubMed, Web of Knowledge, and the Cochrane Library databases for studies evaluating the impact of statin pretreatment on myocardial perfusion in STEMI patients receiving PPCI. RESULTS: Twelve trials were finally included in our meta-analysis. There were no significant differences in patients' baseline characteristics between the statin pretreatment and control groups. Overall pooled analysis showed that patients in the statin pretreatment groups had significantly better epicardial coronary blood flow (measured by Thrombosis in Myocardial Infarction [TIMI] grade, odds ratio [OR]: 0.49, 95% confidence interval [CI]: 0.28 to 0.84; measured by corrected TIMI frame count, mean difference: -5.63; 95% CI: -9.66 to -1.6). A trend toward myocardial tissue level perfusion improvement was seen in the statin pretreatment arm rather than the control arm (measured by myocardial blush grade, OR: 0.74; 95% CI: 0.50 to 1.09). CONCLUSIONS: This present meta-analysis suggests that statin pretreatment might be effective in improving myocardial perfusion in STEMI patients.

Pharmacoinvasive therapy for ST elevation myocardial infarction in China: a pilot study.

Most patients with acute ST-elevation myocardial infarction (STEMI) cannot receive timely primary percutaneous coronary intervention (PCI) because of lack of facilities or delays in patient transfer or catheterization team mobilization. In these patients, early routine post-thrombolysis PCI might be a reasonable, useful strategy. This study investigated feasibility and safety of early PCI after successful half-dose alteplase reperfusion in a Chinese population. Patients with STEMI received half-dose alteplase if expected time delay to PCI was ≥90 min. Patients who reached clinical criteria of successful thrombolysis reperfusion were recommended to undergo diagnostic angiography within 3-24 h after thrombolysis. Patients with residual stenosis ≥70% in the infarct-related artery underwent PCI, regardless of flow or patency status. Epicardial arterial flow was assessed using thrombolysis in myocardial infarction (TIMI) flow grade and TIMI frame count (CTFC). Myocardial perfusion was assessed using myocardial blush grade (MBG) and TIMI myocardial perfusion frame count (TMPFC). Forty-nine patients were enrolled and underwent diagnostic angiography 3-11.3 h (median 6.5 h) after thrombolysis. Forty-six patients underwent PCI. No procedure-related complications occurred, except two patients who had no reflow after PCI. Twenty-two (47.8%) patients had TIMI grade 3 flow before PCI and 33 (71.7%) after PCI. CTFC was significantly improved after PCI (48.5 ± 32.1 vs. 37.9 ± 25.6, P = 0.01). MBG and TMPFC exhibited a similar improving trend after PCI, and the best myocardial perfusion tended to be achieved 3-12 h after lysis. During the 30-day follow-up, there were two deaths. The composite end point of death, cardiogenic shock, heart failure, reinfarction, and recurrent ischemia occurred in four patients. TIMI minor bleeding occurred in four patients. No TIMI major bleeding and stroke occurred. Early routine PCI after half-dose alteplase thrombolysis in Chinese population appears feasible. A larger clinical trial should be designed to further elucidate its efficacy and safety. Early PCI after thrombolysis in STEMI: The EARLY-PCI pilot feasibility study, ChiCTR-TNC-11001363.

Variants in COMT and DBH influence on response inhibition ability in Chinese Han females.

Catechol-O-methyltransferase (COMT) and dopamine-beta hydroxylase (DBH) are key enzymes to breakdown dopamine. Some previous studies have indicated that val158met in COMT and 19 bp insertion/deletion in 5' flank of DBH are related to the performance of executive function. To further investigate the associations of the two genes with executive function, we performed a population-based study in a Chinese Han population. The results indicated that val158met in COMT and the 19 bp insertion/deletion of DBH were associated with the average reaction time of response inhibition in female group (P = 0.01, P = 0.03), respectively. Furthermore, there was a significant interaction of the two genes on the reaction time (P = 0.006). This present study suggests that not only do COMT and DBH influence independently on response inhibition in females, but also exert a significant interaction on response inhibition.