Human DUS1L catalyzes dihydrouridine modification at tRNA positions 16/17, and DUS1L overexpression perturbs translation.

Human cytoplasmic tRNAs contain dihydrouridine modifications at positions 16 and 17 (D16/D17). The enzyme responsible for D16/D17 formation and its cellular roles remain elusive. Here, we identify DUS1L as the human tRNA D16/D17 writer. DUS1L knockout in the glioblastoma cell lines LNZ308 and U87 causes loss of D16/D17. D formation is reconstituted in vitro using recombinant DUS1L in the presence of NADPH or NADH. DUS1L knockout/overexpression in LNZ308 cells shows that DUS1L supports cell growth. Moreover, higher DUS1L expression in glioma patients is associated with poorer prognosis. Upon vector-mediated DUS1L overexpression in LNZ308 cells, 5' and 3' processing of precursor tRNATyr(GUA) is inhibited, resulting in a reduced mature tRNATyr(GUA) level, reduced translation of the tyrosine codons UAC and UAU, and reduced translational readthrough of the near-cognate stop codons UAA and UAG. Moreover, DUS1L overexpression increases the amounts of several D16/D17-containing tRNAs and total cellular translation. Our study identifies a human dihydrouridine writer, providing the foundation to study its roles in health and disease.

Suppression of autophagy induces senescence in the heart.

Aging is a critical risk factor for heart disease, including ischemic heart disease and heart failure. Cellular senescence, characterized by DNA damage, resistance to apoptosis and the senescence-associated secretory phenotype (SASP), occurs in many cell types, including cardiomyocytes. Senescence precipitates the aging process in surrounding cells and the organ through paracrine mechanisms. Generalized autophagy, which degrades cytosolic materials in a non-selective manner, is decreased during aging in the heart. This decrease causes deterioration of cellular quality control mechanisms, facilitates aging and negatively affects lifespan in animals, including mice. Although suppression of generalized autophagy could promote senescence, it remains unclear whether the suppression of autophagy directly stimulates senescence in cardiomyocytes, which, in turn, promotes myocardial dysfunction in the heart. We addressed this question using mouse models with a loss of autophagy function. Suppression of general autophagy in cardiac-specific Atg7 knockout (Atg7cKO) mice caused accumulation of senescent cardiomyocytes. Induction of senescence via downregulation of Atg7 was also observed in chimeric Atg7 cardiac-specific KO mice and cultured cardiomyocytes in vitro, suggesting that the effect of autophagy suppression upon induction of senescence is cell autonomous. ABT-263, a senolytic agent, reduced the number of senescent myocytes and improved cardiac function in Atg7cKO mice. Suppression of autophagy and induction of senescence were also observed in doxorubicin-treated hearts, where reactivation of autophagy alleviated senescence in cardiomyocytes and cardiac dysfunction. These results suggest that suppression of general autophagy directly induces senescence in cardiomyocytes, which in turn promotes cardiac dysfunction.

Suppression of autophagy induces senescence in the heart.

Aging is a critical risk factor for heart disease, including ischemic heart disease and heart failure. Cellular senescence, characterized by DNA damage, resistance to apoptosis and the senescence-associated secretory phenotype (SASP), occurs in many cell types, including cardiomyocytes. Senescence precipitates the aging process in surrounding cells and the organ through paracrine mechanisms. Generalized autophagy, which degrades cytosolic materials in a non-selective manner, is decreased during aging in the heart. This decrease causes deterioration of cellular quality control mechanisms, facilitates aging and negatively affects lifespan in animals, including mice. Although suppression of generalized autophagy could promote senescence, it remains unclear whether the suppression of autophagy directly stimulates senescence in cardiomyocytes, which, in turn, promotes myocardial dysfunction in the heart. We addressed this question using mouse models with a loss of autophagy function. Suppression of general autophagy in cardiac-specific Atg7 knockout ( Atg7 cKO) mice caused accumulation of senescent cardiomyocytes. Induction of senescence via downregulation of Atg7 was also observed in chimeric Atg7 cardiac-specific KO mice and cultured cardiomyocytes in vitro , suggesting that the effect of autophagy suppression upon induction of senescence is cell autonomous. ABT-263, a senolytic agent, reduced the number of senescent myocytes and improved cardiac function in Atg7 cKO mice. Suppression of autophagy and induction of senescence were also observed in doxorubicin-treated hearts, where activation of autophagy alleviated senescence in cardiomyocytes and cardiac dysfunction. These results suggest that suppression of general autophagy directly induces senescence in cardiomyocytes, which in turn promotes cardiac dysfunction.

Endoplasmic Reticulum Selective Autophagy Alleviates Anthracycline-Induced Cardiotoxicity.

Background: The administration of anthracycline drugs induces progressive and dose-related cardiac damage through several cytotoxic mechanisms, including endoplasmic reticulum (ER) stress. The unfolded protein response plays a crucial role for mitigating misfolded protein accumulation induced by excessive ER stress. Objectives: We aimed to clarify whether endoplasmic reticulum-selective autophagy machinery (ER-phagy) serves as an alternative system to protect cardiomyocytes from ER stress caused by anthracycline drugs. Methods: Primary cultured cardiomyocytes, H9c2 cell lines, and cardiomyocyte-specific transgenic mice, all expressing ss-RFP-GFP-KDEL proteins, were used as ER-phagy reporter models. We generated loss-of-function models using RNA interference or gene-trap mutagenesis techniques. We assessed phenotypes and molecular signaling pathways using immunoblotting, quantitative polymerase chain reaction, cell viability assays, immunocytochemical and histopathological analyses, and cardiac ultrasonography. Results: The administration of doxorubicin (Dox) activated ER-phagy in ss-RFP-GFP-KDEL-transduced cardiomyocytes. In addition, Dox-induced cardiomyopathy models of ER-phagy reporter mice showed marked activation of ER-phagy in the myocardium compared to those of saline-treated mice. Quantitative polymerase chain reaction analyses revealed that Dox enhanced the expression of cell-cycle progression gene 1 (CCPG1), one of the ER-phagy receptors, in H9c2 cells. Ablation of CCPG1 in H9c2 cells resulted in the reduced ER-phagy activity, accumulation of proapoptotic proteins, and deterioration of cell survival against Dox administration. CCPG1-hypomorphic mice developed more severe deterioration in systolic function in response to Dox compared to wild-type mice. Conclusions: Our findings highlight a compensatory role of CCPG1-driven ER-phagy in reducing Dox toxicity. With further study, ER-phagy may be a potential therapeutic target to mitigate Dox-induced cardiomyopathy.

Porphyromonas gingivalis, a periodontal pathogen, impairs post-infarcted myocardium by inhibiting autophagosome-lysosome fusion.

While several previous studies have indicated the link between periodontal disease (PD) and myocardial infarction (MI), the underlying mechanisms remain unclear. Autophagy, a cellular quality control process that is activated in several diseases, including heart failure, can be suppressed by Porphyromonas gingivalis (P.g.). However, it is uncertain whether autophagy impairment by periodontal pathogens stimulates the development of cardiac dysfunction after MI. Thus, this study aimed to investigate the relationship between PD and the development of MI while focusing on the role of autophagy. Neonatal rat cardiomyocytes (NRCMs) and MI model mice were inoculated with wild-type P.g. or gingipain-deficient P.g. to assess the effect of autophagy inhibition by P.g. Wild-type P.g.-inoculated NRCMs had lower cell viability than those inoculated with gingipain-deficient P.g. This study also revealed that gingipains can cleave vesicle-associated membrane protein 8 (VAMP8), a protein involved in lysosomal sensitive factor attachment protein receptors (SNAREs), at the 47th lysine residue, thereby inhibiting autophagy. Wild-type P.g.-inoculated MI model mice were more susceptible to cardiac rupture, with lower survival rates and autophagy activity than gingipain-deficient P.g.-inoculated MI model mice. After inoculating genetically modified MI model mice (VAMP8-K47A) with wild-type P.g., they exhibited significantly increased autophagy activation compared with the MI model mice inoculated with wild-type P.g., which suppressed cardiac rupture and enhanced overall survival rates. These findings suggest that gingipains, which are virulence factors of P.g., impair the infarcted myocardium by cleaving VAMP8 and disrupting autophagy. This study confirms the strong association between PD and MI and provides new insights into the potential role of autophagy in this relationship.

Synthesis of Isotopic Atropisomers Based on 12C/13C Discrimination.

Quinazolin-4-one derivatives possessing an isotopic atropisomerism (isotopic N-C axial chirality) based on ortho-12CH3/13CH3 discrimination were prepared. The diastereomeric quinazolin-4-ones bearing an asymmetric carbon as well as an isotopic atropisomerism were clearly discriminated by 1H and 13C NMR spectra and revealed to possess high rotational stability and stereochemical purity.

Contribution of periodontal health in cardiovascular secondary prevention: Analyses on hospitalized patients in cardiology units.

AIM: To investigate the association between dental health and incident cardiovascular disease (CVD) in secondary prevention setting. MATERIALS AND METHODS: A total of 888 patients with known CVD hospitalized in the cardiology unit were prospectively enrolled. We assessed the association between missing teeth and three variables of periodontitis and major adverse cardiovascular events (MACE), defined as a composite of cardiac death, acute myocardial infarction, stroke and hospital re-admission for congestive heart failure. RESULTS: During a median (Q1, Q3) follow-up of 4.6 (1.4, 6.7) years, an additional missing tooth was associated with a 3% (95% confidence interval [CI]: 1%-5%) higher hazard of MACE (p = .004). Compared with patients with 0 to ≤4 missing teeth, periods free from MACE (95% CI) by 5 years of follow-up were, on average, shorter by 0.17 (-0.04 to 0.37) years, 0.26 (0.04-0.49) years and 0.59 (0.34-0.85) years in patients with 5 to ≤7, 8 to ≤13 and >13 missing teeth, respectively. No significant associations were observed between periodontal measures and MACE incidence. CONCLUSIONS: In hospitalized patients with existing CVD, the total number of missing teeth was associated with incident MACE.

Erratum to "Association between periodontal disease and pericardial adipose tissue in patients with cardiovascular disease" [American Heart Journal Plus: Cardiol. Res. and Pract. Volume 30, 2023, 100,298].

[This corrects the article DOI: 10.1016/j.ahjo.2023.100298.].

Association between periodontal disease and pericardial adipose tissue in patients with cardiovascular disease.

Background: Periodontal disease (PD) is associated with an increased risk of cardiovascular disease (CVD). Pericardial adipose tissue (PAT) is known as a marker of progressive CVD. This study sought to assess the association between PD and PAT in patients with CVD. Methods: We retrospectively investigated 135 patients admitted for CVD who underwent computed tomography coronary angiography (CTCA) and periodontal examinations. Periodontal assessment using the community periodontal index (CPI) was based on the probing pocket depth around teeth. Patients with CPI ≥3 were categorized as having PD. PAT volume was measured with a quantitative semi-automated procedure using CTCA images. Patients were divided into tertiles according to PAT volume. Baseline characteristics and PD findings were compared among the tertiles. Results: Eighty-six patients were diagnosed with PD (63.7 %). Mean PAT volume was 181.4 ml, and patients were categorized as small-PAT (PAT <148.9 ml), intermediate-PAT (148.9 ml ≤ PAT ≤204.6 ml), and large-PAT (PAT >204.6 ml). The prevalence of PD was significantly higher in large-PAT (38/46, 82.6 %) than in small-PAT (18/45, 40.0 %) and intermediate-PAT (30/44, 68.2 %) patients. Multivariate logistic regression analysis showed that body weight, history of hypertension, and the presence of PD were independent predictors for large-PAT (odds ratio [OR]: 1.12, P < 0.001, OR: 3.97, P = 0.017, and OR: 4.18, P = 0.0078, respectively). Conclusion: The presence and severity of PD were significantly correlated with PAT volume, which has been associated with progressive CVD. Further prospective studies are warranted to assess the impact of PD on the onset and outcomes of CVD.

The Pathophysiological Significance of "Mitochondrial Ejection" from Cells.

Mitochondria have beneficial effects on cells by producing ATP and contributing to various biosynthetic procedures. On the other hand, dysfunctional mitochondria have detrimental effects on cells by inducing cellular damage, inflammation, and causing apoptosis in response to various stimuli. Therefore, a series of mitochondrial quality control pathways are required for the physiological state of cells to be maintained. Recent research has provided solid evidence to support that mitochondria are ejected from cells for transcellular degradation or transferred to other cells as metabolic support or regulatory messengers. In this review, we summarize the current understanding of the regulation of mitochondrial transmigration across the plasma membranes and discuss the functional significance of this unexpected phenomenon, with an additional focus on the impact on the pathogenesis of cardiovascular diseases. We also provide some perspective concerning the unrevealed mechanisms underlying mitochondrial ejection as well as existing problems and challenges concerning the therapeutic application of mitochondrial ejection.

Neutrophil extracellular traps-mediated Beclin-1 suppression aggravates atherosclerosis by inhibiting macrophage autophagy.

A growing body of evidence suggests that neutrophil extracellular traps (NETs) critically contribute to the development of atherosclerosis. However, the detailed mechanism of how NETs promote atherogenesis remains unknown. In this study, we explored the role of NETs for promoting atherosclerosis by modulating the activity of autophagy in macrophages. NETs were effectively induced by a nicotine administration to the HL-60 cell-derived neutrophil-like cells. Treatment with NETs markedly suppressed both autophagosome formation and autophagosome-lysosome fusion in 7-ketocholesterol-treated macrophages, which are accompanied by the enhancement of inflammasome activity. NETs upregulate epidermal growth factor receptor (EGFR) activity, which enhances Beclin-1 phosphorylation of the tyrosine residues of Beclin-1 by EGFR, inhibits the PI3 kinase activity of the Beclin1-Vps34 complex, and suppresses autophagosome formation in macrophages. Furthermore, NET-induced activation of EGFR allows Rubicon to increase its expression, thereby suppressing autophagosome-lysosome fusion. In vivo experiments revealed that the suppression of NET formation by ablating peptidyl arginine deiminase-4 in neutrophil leukocytes resulted in the attenuation of atherosclerotic plaques in a nicotine-administered HFD-fed ApoE -/- mice. Taken together, these results suggest that NET-mediated EGFR-Beclin-1 signaling in the macrophages promotes atherogenesis by autophagy inhibition-mediated inflammasome activation.

Periodontitis was associated with worse clinical outcomes after catheter ablation for paroxysmal atrial fibrillation.

Background: Periodontitis (PD), a common chronic inflammatory disease, may be associated with the subsequent development of atrial fibrillation (AF) through a mechanism of systemic inflammation. However, little is known about the impact of PD on the recurrence of atrial fibrillation after catheter ablation (CA). Methods: A total of 132 patients (age 62.2 ± 10.6 years; 72.7% male) who underwent periodontal examinations and the first CA for paroxysmal atrial fibrillation (PAF) were investigated. Clinical periodontal examination was performed by independent trained periodontists, and patients were diagnosed with PD when the maximum periodontal probing depth was equal to or greater than 4 mm and bleeding on probing was evident. Of these, 71 patients (54%) were categorized as those with PD (PD group) and the other 61 (46%) as those without PD (non-PD group). Pulmonary vein isolation was performed in a standard fashion. Results: Kaplan-Meier curve analysis revealed worse atrial arrhythmia recurrence-free survival probabilities after CA for PAF in the PD group than in the non-PD group (64.8% versus 80.3%, respectively; p = 0.024) during a median follow-up period of 3.0 (interquartile range: 1.1-6.4) years. Cox regression analysis revealed PD as a significant predictor of arrhythmia recurrence (hazard ratio: 2.063, 95% confidence interval: 1.018-4.182), after adjusting for age and gender. Conclusion: Periodontitis was independently associated with an increased risk of arrhythmia recurrence after the first CA for PAF. Our results may suggest that the periodontal status is potentially a modifiable determinant of the outcomes after PAF ablation, and further prospective studies are warranted.

Effect of Periodontal Disease on Long-Term Outcomes After Percutaneous Coronary Intervention for De Novo Coronary Lesions in Non-Smokers.

BACKGROUND: This study aimed to investigate the effect of periodontal disease (PD) on the outcomes of patients with coronary artery disease (CAD) treated with percutaneous coronary intervention (PCI).Methods and Results: The study included 77 consecutive non-smoking patients with de novo coronary lesions treated with a drug-eluting stent (DES). Periodontal measurements, including the community periodontal index (CPI), were performed by independent periodontists. A CPI score of ≥3 was used to define PD. The occurrence of major adverse cardiac events (MACEs), which were defined as a composite of cardiovascular death, non-fatal myocardial infarction, target lesion revascularization, or non-target lesion revascularization, was compared between patients with and without PD. Of the 77 patients, 49 (63.6%) exhibited a CPI score of 3 or 4 and were assigned to the PD group. The remaining 28 patients (36.4%) were assigned to the non-PD group. Baseline clinical characteristics and angiographic findings were comparable between the 2 groups. MACEs occurred in 13 (26.5%) of the PD patients and 2 (7.1%) of the non-PD patients. Kaplan-Meier analysis showed a significantly lower MACE-free survival rate in the PD group than for the non-PD group (P=0.034). CONCLUSIONS: PD at baseline was associated with an increased risk of MACEs in CAD patients who were treated with a DES for de novo coronary lesions.

Identification of Novel GCK and HNF4α Gene Variants in Japanese Pediatric Patients with Onset of Diabetes before 17 Years of Age.

BACKGROUND: Maturity-onset diabetes of the young (MODY) is commonly misdiagnosed as type 1 or type 2 diabetes. Common reasons for misdiagnosis are related to limitations in genetic testing. A precise molecular diagnosis is essential for the optimal treatment of patients and allows for early diagnosis of their asymptomatic family members. OBJECTIVE: The aim of this study was to identify rare monogenic variants of common MODY genes in Japanese pediatric patients. METHODS: We investigated 45 Japanese pediatric patients based on the following clinical criteria: development of diabetes before 17 years of age, a family history of diabetes, testing negative for glutamate decarboxylase-65 (GAD 65) antibodies and insulinoma-2-associated autoantibodies (IA-2A), no significant obesity, and evidence of endogenous insulin production. Genetic screening for MODY1 (HNF4α), MODY2 (GCK), MODY3 (HNF1α), and MODY5 (HNF1ß) was performed by direct sequencing followed by multiplex ligation amplification assays. RESULTS: We identified 22 missense variants (3 novel variants) in 27 patients (60.0%) in the GCK, HNF4α, and HNF1α genes. We also detected a whole exon deletion in the HNF1ß gene and an exon 5-6 aberration in the GCK gene, each in one proband (4.4%). There were a total of 29 variations (64.4%), giving a relative frequency of 53.3% (24/45) for GCK, 2.2% (1/45) for HNF4α, 6.7% (3/45) for HNF1α, and 2.2% (1/45) for HNF1ß genes. CONCLUSIONS: Clinicians should consider collecting and assessing detailed clinical information, especially regarding GCK gene variants, in young antibody-negative patients with diabetes. Correct molecular diagnosis of MODY better predicts the clinical course of diabetes and facilitates individualized management.

Effects of Alcohol Consumption and Smoking on the Onset of Hypertension in a Long-Term Longitudinal Study in a Male Workers' Cohort.

AIM: To determine the effects of alcohol consumption and smoking on the onset of hypertension in a long-term longitudinal study. METHODS: 7511 non-hypertensive male workers were enrolled. This cohort study was performed over an 8-year period using the results of the annual workers-health screening. The end-point was defined as systolic blood pressure ≥ 140 mmHg, diastolic blood pressure ≥ 90 mmHg, or use of antihypertensive drugs. For alcohol consumption, weekly alcohol intake (g ethanol/week) was estimated (1 "gou" = 22 g ethanol). Annual survey data were analyzed by pooled logistic regression that included alcohol consumption, smoking, age, body mass index, job schedule types, habitual exercise, and blood test measurements into the statistical model. RESULTS: A significant positive dose-response relationship between alcohol consumption and onset of hypertension was observed, with synergistic health effects present. Compared with abstainers and nonsmokers, the adjusted odds ratios (95% confidence interval) for the onset of hypertension were: 1.51 (1.27-1.79) for 154 g ethanol/week and nonsmokers, and 1.81 (1.54-2.11) for 154 g ethanol/week and smokers. An interaction between alcohol and smoking was confirmed. CONCLUSIONS: This study provided information useful to the prevention of hypertension. By reducing alcohol consumption and smoking simultaneously, the risk of hypertension may be considerably lowered.

Plasma apolipopotein C-2 elevation is associated with Takayasu arteritis.

Takayasu arteritis (TAK) is an autoimmune systemic arteritis of unknown etiology. Although a number of investigators have attempted to determine biomarkers for diagnosing TAK, there exist no specific serological markers of this intractable disease. We undertook the exploration of novel serological markers which could be useful for an accurate diagnosis of TAK using an unbiased proteomics approach. The purified plasma samples from untreated patients with TAK and healthy individuals were separated by two-dimensional electrophoresis. The differentially expressed protein spots were detected by gel comparison and identified using matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MS). Next, we validated plasma concentrations of identified proteins by enzyme-linked immunosorbent assay (ELISA). Two-dimensional electrophoresis and numerical analysis revealed 19 spots and 3 spot clusters whose sum of the sample averages was ≥ 0.01, and the average concentrations were ≥ 1.5 times in the patient group compared with the control group. Among them, 10 spots and spot clusters that met the condition of the average spot concentration being 2.5 times more than that in the control group were selected. After processing these spots using MS and conducting MS/MS ion search, we identified 10 proteins: apolipoprotein C-2 (ApoC-2), actin, apolipoprotein A-1, complement C3, kininogen-1, vitronectin, α2-macroglobulin, 14-3-3 protein ζ/δ, complement C4, and inter-α-trypsin inhibitor heavy chain H4 isoform 1 precursor. Finally, ELISA demonstrated that plasma ApoC-2 level was significantly elevated in patients with TAK compared with that in healthy individuals. Thus, ApoC-2 would be a promising candidate biomarker for TAK diagnosis.

Linagliptin, A Xanthine-Based Dipeptidyl Peptidase-4 Inhibitor, Ameliorates Experimental Autoimmune Myocarditis.

This study sought to show the mechanism of how to ameliorate experimental autoimmune myocarditis (EAM) by administering dipeptidyl peptidase (DPP)-4 inhibitor linagliptin. The number of RAR-related orphan nuclear receptor gamma-positive Th17 cells infiltrated to the EAM myocardium was significantly attenuated by linagliptin treatment. Tandem mass spectrometry-based analysis demonstrated that DPP-4 binds to cathepsin G in EAM hearts, thereby protecting cathepsin G activity through inhibiting SerpinA3N activity. Linagliptin suppresses oxidative stress in EAM hearts as well. Thus, we found that DPP-4 plays a detrimental role in the progression of EAM by interacting with cathepsin G, which, in turn, suppresses SerpinA3N activity.

Predictive values of early head computed tomography for survival outcome after cardiac arrest in childhood: a pilot study.

Predicting outcomes of children after cardiac arrest (CA) remains challenging. To identify useful prognostic markers for pediatric CA, we retrospectively analyzed the early findings of head computed tomography (CT) of patients. Subjects were non-traumatic, out-of-hospital CA patients < 16 years of age who underwent the first head CT within 24 h in our institute from 2006 to 2018 (n = 70, median age: 4 months, range 0-163). Of the 24 patients with return of spontaneous circulation, 14 survived up to 30 days after CA. The degree of brain damage was quantitatively measured with modified methods of the Alberta Stroke Program Early CT Score (mASPECTS) and simplified gray-matter-attenuation-to-white-matter-attenuation ratio (sGWR). The 14 survivors showed higher mASPECTS values than the 56 non-survivors (p = 0.035). All 3 patients with mASPECTS scores ≥ 20 survived, while an sGWR ≥ 1.14 indicated a higher chance of survival than an sGWR < 1.14 (54.5% vs. 13.6%). Follow-up magnetic resonance imaging for survivors validated the correlation of the mASPECTS < 15 with severe brain damage. Thus, low mASPECTS scores were associated with unfavorable neurological outcomes on the Pediatric Cerebral Performance Category scale. A quantitative analysis of early head CT findings might provide clues for predicting survival of pediatric CA.