Coronary CT Angiography-Based Radiomics to Predict Vessel-Specific Ischemia by Stress Dynamic CT Myocardial Perfusion Imaging.

RATIONALE AND OBJECTIVES: To investigate the predictive value of coronary CT angiography (CCTA)-based radiomics for vessel-specific ischemia by stress dynamic CT myocardial perfusion imaging (MPI). MATERIALS AND METHODS: Patients with typical angina/atypical angina/non-angina chest pain who underwent both stress dynamic CT MPI and CCTA scans were retrospectively enrolled. The following models were constructed for ischemic prediction using logistic regression and CCTA-derived quantitative and radiomic features: plaque quantitative model, lumen quantitative model, CT-fractional flow reserve (CT-FFR) model, integrative quantitative model, plaque radiomic model, peri-coronary adipose tissue (pCAT) radiomic model, integrative radiomic model, and quantitative and radiomic fusion model. A relative myocardial blood flow ≤ 0.75 on stress dynamic CT MPI was considered ischemic. The models' performances were quantified by the area under the receiver-operating characteristic curve (AUC). RESULTS: 386 coronary vessels (stenosis grade: 25%∼75%; training set: 200 [ischemia/non-ischemia=96/104]; test set:186 [ischemia/non-ischemia=79/107]) from 326 patients were included. The plaque radiomic model (training/test set: AUC=0.81/0.80) outperformed (p < .05) both the plaque quantitative (training/test set: AUC=0.71/0.68) model and the lumen quantitative (training/test set: AUC=0.69/0.65) model in identifying ischemia. The integrative radiomic model (training/test set: AUC=0.83/0.82) outperformed (p < .05) the CT-FFR model (training/test set: AUC=0.74/0.73) for ischemic prediction. The quantitative and radiomic fusion model (training/test set: AUC=0.86/0.84) outperformed (p < .05) the integrative quantitative model (training/test set: AUC=0.79/0.77) for ischemic detection. CONCLUSION: The plaque and pCAT radiomic features were superior to the plaque and pCAT quantitative features in predicting ischemia and the addition of the radiomic features to the quantitative features for ischemic identification yielded incremental discriminatory value.

Enhanced expression of miR-20a driven by nanog exacerbated the degradation of extracellular matrix in thoracic aortic dissection.

Thoracic aortic dissection (TAD) is a life-threatening vascular disease manifested as intramural bleeding in the medial layers of the thoracic aorta. The key histopathologic feature of TAD is medial degeneration, characterized by depletion of vascular smooth muscle cells (VSMCs) and degradation of extracellular matrix (ECM). MicroRNA, as essential epigenetic regulators, can inhibit the protein expression of target genes without modifying the sequences. This study aimed to elucidate the role and underlying mechanism of miR-20a, a member of the miR-17-92 cluster, in regulating ECM degradation during the pathogenesis of TAD. The expression of the miR-17-92 cluster was significantly increased in synthetic VSMCs derived from TAD lesions compared to contractile VSMCs isolated from normal thoracic aortas. Notably, the expression of miR-20a was increased in VSMCs in response to serum exposure and various stimuli. In TAD lesions, the expression of miR-20a was significantly negatively correlated with that of elastin. Elevated expression of miR-20a was also observed in thoracic aortas of TAD mice induced by ß-aminopropionitrile fumarate and angiotensin II. Overexpression of miR-20a via mimic transfection enhanced the growth and invasive capabilities of VSMCs, with no significant impact on their migratory activity or the expression of phenotypic markers (α-SMA, SM22, and OPN). Silencing of miR-20a with inhibitor transfection mitigated the hyperactivation of MMP2 in VSMCs stimulated by PDGF-bb, as evidenced by reduced levels of active-MMP2 and increased levels of pro-MMP2. Subsequently, TIMP2 was identified as a novel target gene of miR-20a. The role of miR-20a in promoting the activation of MMP2 was mediated by the suppression of TIMP2 expression in VSMCs. In addition, the elevated expression of miR-20a was found to be directly driven by Nanog in VSMCs. Collectively, these findings indicate that miR-20a plays a crucial role in maintaining the homeostasis of the thoracic aortic wall during TAD pathogenesis and may represent a potential therapeutic target for TAD.

Integrating Experimental and Computational Analyses of Yeast Protein Profiles for Optimizing the Production of High-Quality Microbial Proteins.

Microbial proteins represent a promising solution to address the escalating global demand for protein, particularly in regions with limited arable land. Yeasts, such as Saccharomyces cerevisiae, are robust and safe protein-producing strains. However, the utilization of non-conventional yeast strains for microbial protein production has been hindered, partly due to a lack of comprehensive understanding of protein production traits. In this study, we conducted experimental analyses focusing on the growth, protein content, and amino acid composition of nine yeast strains, including one S. cerevisiae strain, three Yarrowia lipolytica strains, and five Pichia spp. strains. We identified that, though Y. lipolytica and Pichia spp. strains consumed glucose at a slower rate compared to S. cerevisiae, Pichia spp. strains showed a higher cellular protein content, and Y. lipolytica strains showed a higher glucose-to-biomass/protein yield and methionine content. We further applied computational approaches to explain that metabolism economy was the main underlying factor for the limited amount of scarce/carbon-inefficient amino acids (such as methionine) within yeast cell proteins. We additionally verified that the specialized metabolism was a key reason for the high methionine content in Y. lipolytica strains, and proposed Y. lipolytica strain as a potential producer of high-quality single-cell protein rich in scarce amino acids. Through experimental evaluation, we identified Pichia jadinii CICC 1258 as a potential strain for high-quality protein production under unfavorable pH/temperature conditions. Our work suggests a promising avenue for optimizing microbial protein production, identifying the factors influencing amino acid composition, and paving the way for the use of unconventional yeast strains to meet the growing protein demands.

Nitroplasts suggest the creation of artificial nitrogen-fixing eukaryotes.

It is believed that nitrogen-fixing eukaryotes do not exist in nature, and constructing such eukaryotes is extremely challenging. Coale et al., however, have identified the first eukaryote capable of fixing nitrogen through a nitroplast organelle. Understanding the eukaryotic nitrogen-fixing machinery may advance the development of artificial nitrogen-fixing crops and industrial yeasts.

High serum uric acid is a risk factor for arterial stiffness in a Chinese hypertensive population: a cohort study.

The prospective cohort study was to explore the association between serum uric acid (SUA) and arterial stiffness in a Chinese hypertensive population. A total of 7444 participants with hypertension who completed two or more measurements of brachial-ankle pulse wave velocity (baPWV) and baseline SUA detection were followed-up in the Kailuan Study from 2010 to 2020. A restricted cubic spline curve was used to verify whether there was a linear association between baseline SUA and arterial stiffness. A Cox proportional hazard regression model was used to explore the association of between baseline SUA and the incidence of arterial stiffness. Our results showed that the restricted cubic spline curve revealed a linear relationship between baseline SUA and arterial stiffness in total participants (p < 0.001). After follow-up 4.6 ± 2.8 years, Kaplan-Meier survival curves indicated that the risk of arterial stiffness was increased in the high level of baseline SUA (Log-rank p = 0.0002). After adjusting for potential confounding factors, the HR (95% CI) for risk of stiffness was 1.33 (1.17-1.52, p < 0.001) in the highest SUA group. Hierarchical analysis showed that the HRs (95% CI) for risk of arterial stiffness were 1.45 (1.25-1.69), 1.38 (1.19-1.60), 1.41 (1.21-1.64), and 1.35 (1.15-1.58) in the highest SUA group of males, <65 years old, not taking antihypertensive drugs, and failure to achieve the control targets of blood pressure respectively (p < 0.001). These results reveal that high SUA is a risk factor for arterial stiffness in the Chinese hypertensive population.

Experimental observation on a new chimney-shaped mechanical valve completely implanted above the mitral annulus in animals.

Current commercially available prosthetic valves suffer from limited size, high requirements for implantation technique, subvalvular structural destruction, and valve dysfunction due to proliferation of fibrous endothelial tissue. This study aims to perform the preclinical large animal experiments for surgically implanting a chimney-shaped artificial mechanical heart valve with zero left ventricular occupancy, which fully accommodates the movement of the valve leaflets in the valve frame and realizes completely supra-annular surgical implantation. A total of 7 sheep underwent the replacement of artificial valve, and 5 sheep survived normally until anatomical examination. The mechanical properties of these artificial mitral valves remain functionally normal. There was no obvious thromboembolism around the artificial valve and in the important organs. The tissue layer of suture ring was completely organized and endothelialized, and the thickness of tissue layer was about 0.6-1.0 mm. The follow-up of echocardiography showed that the left ventricular ejection fraction was normal (60-70%) before and 6 months after operation. The results of transvalvular pressure gradient and blood flow velocity of artificial valve were normal. Left ventricular retrograde angiography showed that the artificial valve was completely located in the left atrium with good position and normal opening and closing. There was no obvious perivalvular leakage and other abnormalities. At 3 and 6 months, there were no obvious abnormalities in blood routine test, liver and kidney function, and other indexes. The new chimney-shaped artificial mechanical valve implanted completely above the mitral annulus had good wear resistance, histocompatibility, and antithrombotic and hemodynamic performance.

Decreased expression of RPL15 and RPL18 exacerbated the calcification of valve interstitial cells during aortic valve calcification.

Calcific aortic valve disease (CAVD) is the most common valvular heart disease, with an increasing prevalence due to an aging population. The pathobiology of CAVD is a multifaceted and actively regulated process, but the detailed mechanisms have not been elucidated. The present study aims to identify the differentially expressed genes (DEGs) in calcified aortic valve tissues, and to analyze the correlation between DEGs and clinical features in CAVD patients. The DEGs were screened by microarray in normal and CAVD groups (n = 2 for each group), and confirmed by quantitative real-time polymerase chain reaction in normal (n = 12) and calcified aortic valve tissues (n = 34). A total of 1048 DEGs were identified in calcified aortic valve tissues, including 227 upregulated mRNAs and 821 downregulated mRNAs. Based on multiple bioinformatic analyses, three 60S ribosomal subunit components (RPL15, RPL18, and RPL18A), and two 40S ribosomal subunit components (RPS15 and RPS21) were identified as the top 5 hub genes in the protein-protein interaction network of DEGs. The expression of RPL15 and RPL18 was also found significantly decreased in calcified aortic valve tissues (both p < .01), and negatively correlated with the osteogenic differentiation marker OPN in CAVD patients (both p < .01). Moreover, inhibition of RPL15 or RPL18 exacerbated the calcification of valve interstitial cells under osteogenic induction conditions. The present study proved that decreased expression of RPL15 and RPL18 was closely associated with aortic valve calcification, which provided valuable clues to find therapeutic targets for CAVD.

Outcomes of reoperation for total arch replacement combined with frozen elephant trunk after previous cardiovascular surgery.

BACKGROUND: Aortic arch replacement(TAR) combined with frozen elephant trunk (FET) technique is a high-risk operation after previous cardiovascular surgery. The aim of the study was to review our strategy and outcomes in this cohort. METHOD: Data were reviewed for patients who underwent TAR combined with FET after previous cardiovascular surgery from January 2010 to December 2020. The patients were divided into elective group and non-selective group. RESULTS: 63 eligible patients were divided into elective(n = 44) and non-elective(n = 19) groups. The interval between two operations was shorter in non-elective group than elective groups (P = 0.001). The indication for reoperation was different in two groups (P = 0.000), however, the type of reoperations has no differences. Cardiopulmonary bypass time was shorter in elective group than non-elective group (P = 0.000). The over-all 30-day mortality rate was 17.5%, and it was higher in non-elective group (P = 0.013). The 24h drainage increased in non-elective group (P = 0.001) as well as re-explore rate for bleeding (P = 0.022). Postoperative hospital stay prolonged in non-elective group (P = 0.002). However, rates of survival without further aortic events were 72.3 ± 7.1% in elective group, 72.9 ± 13.5% in non-elective group at 5 years, respectively (P = 0. 955). CONCLUSION: Reduced 30-day mortality and shortened post-operative hospital stay was observed in elective group, however, long-term survival rate without reintervention were not affected.

Molecular imaging of fibroblast activity in pressure overload heart failure using [68 Ga]Ga-FAPI-04 PET/CT.

PURPOSE: We aimed to evaluate whether [68 Ga]Ga-FAPI-04 PET/CT could characterize the early stages of cardiac fibrosis in pressure overload heart failure. METHODS: Sprague-Dawley rats underwent abdominal aortic constriction (AAC) (n = 12) and sham surgery (n = 10). All rats were scanned with [68 Ga]Ga-FAPI-04 PET/CT at 2, 4, and 8 weeks after surgery. The expression of fibroblast activation protein (FAP) in the myocardium was detected by immunohistochemistry. [68 Ga]Ga-FAPI-04 PET signal and FAP expression were compared between two groups. RESULTS: Compared with the sham group, the AAC group presented with decreased ejection fraction (EF) and fractional shortening (FS) and increased left ventricular internal dimensions in diastole (LVIDd) and systole (LVIDs) at 4 and 8 weeks (all p < 0.01). The AAC group showed higher [68 Ga]Ga-FAPI-04 accumulation in the heart than the sham group at 2, 4, and 8 weeks, and FAPI increased significantly from 2 to 8 weeks (all p < 0.001). Immunohistochemistry confirmed the higher density of the FAP+ area in the AAC group. The intensity of the [68 Ga]Ga-FAPI-04 correlated with the density of the FAP+ area (p < 0.001). The expression of the [68 Ga]Ga-FAPI-04 at 4 weeks correlated with the deterioration of cardiac function at 8 weeks (EF: R = - 0.87; FS: R = - 0.72; LVIDd: R = 0.77; LVIDs: R = 0.79; all p < 0.001). The AAC group also showed an increased [68 Ga]Ga-FAPI-04 signal in the liver, peaking at 4 weeks and then declining. Cardiac and liver PET signals correlated at 4 weeks in the AAC group (R = 0.69, p = 0.0010), suggesting an early fibrotic link between organs. A combination of the [68 Ga]Ga-FAPI-04 intensity in the heart and liver at 4 weeks better predicted the deterioration of cardiac function at 8 weeks. CONCLUSIONS: The activated fibroblasts in the heart and liver after pressure overload can be monitored by [68 Ga]Ga-FAPI-04 PET/CT, which reveals an early fibrotic link in cardio-liver interactions and could better predict nonischemic heart failure prognosis.

Prognostic Significance of Biventricular and Biatrial Strain in Dilated Cardiomyopathy: Strain Analysis Derived from Cardiovascular Magnetic Resonance.

Background: Dilated cardiomyopathy (DCM) has a poor prognosis and high mortality. The relationship between the deformation capacity of the biatrial and biventricular regions in patients with DCM remains unclear. Methods: This retrospective study used cardiovascular magnetic resonance (CMR) to assess patient enrollment between September 2020 to May 2022. Feature tracking (FT) was used to evaluate biventricular global radial strain (GRS), global circumferential strain (GCS) and global longitudinal strain (GLS). Fast long-axis method was used to evaluate biatrial GLS by analyzing balanced steady-state free precession cine images. The median follow-up period was 362 days (interquartile range: 234 to 500 days). DCM patients were divided into two groups based on the occurrence or non-occurrence of major adverse cardiac event (MACE). The primary endpoint was defined as all-cause death, heart transplantation, and adverse ventricular arrhythmia. The secondary end point included hospitalizations due to heart failure. Cox regression analysis was utilized for variables and Kaplan-Meier survival was utilized for clinical outcomes. Results: There were 124 DCM patients (52.82 ± 12.59 years, 67.74% male) and 53 healthy volunteers (53.17 ± 14.67 years, 52.83% male) recruited in this study. Biventricular GRS, GCS, GLS, and biatrial GLS were significantly impaired in the DCM group compared with the healthy group. In receiver-operating characteristic curve, biatrial GLS and biventricular GRS, GCS, and GLS showed significant prognostic value in predicting MACEs (all p < 0.05). In multivariate Cox regression analysis, left ventricular (LV) GLS offered a significant and independent prognostic value surpassing other CMR parameters in predicting MACE. In Kaplan-Meier analysis, patients with a LV GLS > -4.81% had a significantly higher rate of MACE (Log-rank p < 0.001). Conclusions: LV GLS was independently associated with MACEs in DCM patients by using FT and fast long-axis method derived from CMR. Comprehensive CMR examination including biatrial and biventricular functions should be systematically performed, to understand disease characteristics, as well as improve the risk stratification and therapeutic management for patients with DCM.

Therapeutic overexpression of miR-92a-2-5p ameliorated cardiomyocyte oxidative stress injury in the development of diabetic cardiomyopathy.

BACKGROUND: Diabetic cardiomyopathy (DCM) results from pathological changes in cardiac structure and function caused by diabetes. Excessive oxidative stress is an important feature of DCM pathogenesis. MicroRNAs (miRNAs) are key regulators of oxidative stress in the cardiovascular system. In the present study, we screened for the expression of oxidative stress-responsive miRNAs in the development of DCM. Furthermore, we aimed to explore the mechanism and therapeutic potential of miR-92a-2-5p in preventing diabetes-induced myocardial damage. METHODS: An experimental type 2 diabetic (T2DM) rat model was induced using a high-fat diet and low-dose streptozotocin (30 mg/kg). Oxidative stress injury in cardiomyocytes was induced by high glucose (33 mmol/L). Oxidative stress-responsive miRNAs were screened by quantitative real-time PCR. Intervention with miR-92a-2-5p was accomplished by tail vein injection of agomiR in vivo or adenovirus transfection in vitro. RESULTS: The expression of miR-92a-2-5p in the heart tissues was significantly decreased in the T2DM group. Decreased miR-92a-2-5p expression was also detected in high glucose-stimulated cardiomyocytes. Overexpression of miR-92a-2-5p attenuated cardiomyocyte oxidative stress injury, as demonstrated by increased glutathione level, and reduced reactive oxygen species accumulation, malondialdehyde and apoptosis levels. MAPK interacting serine/threonine kinase 2 (MKNK2) was verified as a novel target of miR-92a-2-5p. Overexpression of miR-92a-2-5p in cardiomyocytes significantly inhibited MKNK2 expression, leading to decreased phosphorylation of p38-MAPK signaling, which, in turn, ameliorated cardiomyocyte oxidative stress injury. Additionally, diabetes-induced myocardial damage was significantly alleviated by the injection of miR-92a-2-5p agomiR, which manifested as a significant improvement in myocardial remodeling and function. CONCLUSIONS: miR-92a-2-5p plays an important role in cardiac oxidative stress, and may serve as a therapeutic target in DCM.

Prognostic significance of myocardial salvage assessed by cardiac magnetic resonance in reperfused ST-segment elevation myocardial infarction.

Aims: Myocardial salvage index (MSI) is attracting increasing attention for predicting prognosis in acute myocardial infarction (AMI); however, the evaluation of MSI is mainly based on contrast agent-dependent cardiac magnetic resonance (CMR) scanning sequences. This study aims to investigate the prognostic value of MSI in reperfused ST-segment elevation myocardial infarction (STEMI) through the contrast agent-free CMR technique. Methods and results: Nighty-two patients with acute STEMI, who underwent CMR after primary percutaneous coronary intervention (PPCI), were finally enrolled. Patients were subcategorized into two groups according to median MSI. T1 and T2 mapping were conducted for measuring infarct size (IS) and area at risk (AAR). IS was significantly larger in < median MSI group than ≥ median MSI group (P < 0.001). AAR between the two groups showed no obvious differences (P = 0.108). Left ventricular ejection fraction (LVEF) was lower in < median MSI group than ≥ median MSI group (P = 0.014). There was an obvious inverse correlation between MSI and reperfusion time (R = -0.440, P < 0.001) and a strong inverse correlation between MSI and IS (R = -0.716, P = 0.011). As for the relationship LVEF, MSI showed positive but weak correlation (R = 0.2265, P < 0.001). Over a median follow-up period of 263 (227-238) days, prevalence of MACEs was significantly higher in the < median MSI group [HR: 0.15 (0.04-0.62); Log-rank P = 0.008]. The univariate Cox regression analysis revealed that LVEF, IS, and MSI were significant predictors for major adverse cardiovascular events (MACEs) (all P < 0.05). In the stepwise multivariate Cox regression analysis, LVEF and MSI were identified as independent parameters for predicting MACEs (both P < 0.05). In the receiver-operating characteristic analysis, LVEF, IS, and MSI showed prognostic value in predicting MACEs with AUCs of 0.809, 0.779, and 0.896, respectively, all (P < 0.05). A combination of MSI with LVEF showed the strongest prognostic value of MACEs (AUC: 0.901, sensitivity: 77.78%, specificity: 98.80%, P < 0.001). Delong's test showed that the combination of LVEF with MSI had an incremental value than LVEF itself in predicting MACEs (P = 0.026). Conclusion: Contrast agent-free CMR technique provides a reliable evaluation of MSI, which contributes to assessing the efficacy of reperfusion therapy and predicting the occurrence of MACEs.

The Combination of Feature Tracking and Late Gadolinium Enhancement for Identification Between Hypertrophic Cardiomyopathy and Hypertensive Heart Disease.

Background: The differentiation between hypertrophic cardiomyopathy (HCM) and hypertensive heart disease (HHD) is challenging due to similar myocardial hypertrophic phenotype. The purpose of this study is to evaluate the feasibility of cardiovascular magnetic resonance feature tracking (CMR-FT) and late gadolinium enhancement (LGE) to distinguish between HCM and HHD and the potential relationship between myocardial strain and cardiac functional parameters. Methods: One hundred and seventy subjects (57 HCM, 45 HHD, and 68 controls) underwent 3.0 T CMR, including steady-state free precession cines and LGE images. Global and segmental (basal, mid, and apical) analyses of myocardial radial, circumferential, longitudinal strain, and left ventricular (LV) torsion, as well as global and 16 segments of LGE were assessed. The multivariate analysis was used to predict the diagnostic ability by combining comprehensive myocardial strain parameters and LGE. Results: Global radial strain (GRS), global circumferential strain (GCS), and LV torsion were significantly higher in the HCM group than in the HHD group (GRS, 21.18 ± 7.52 vs. 14.56 ± 7.46%; GCS, -13.34 ± 3.52 vs. -10.11 ± 4.13%; torsion, 1.79 ± 0.69 vs. 1.23 ± 0.65 deg/cm, all P < 0.001). A similar trend was also seen in the corresponding strain rate. As for segmental strain analysis, basal radial strain (BRS), basal circumferential strain (BCS), basal longitudinal strain (BLS), mid-radial strain (MRS), and mid-circumferential strain (MCS) were higher in the HCM group than in the HHD group (all P < 0.001). The receiver operating characteristic (ROC) results showed that the area under the curve (AUC) of LGE in the mid-interventricular septum (mIVS) was the highest among global and segmental LGE analyses. On the multivariate regression analysis, a combined model of LGE (mIVS) with GRS obtained the highest AUC value, which was 0.835 with 88.89% sensitivity and 70.18% specificity, respectively. In addition, for patients with HCM, GRS, GCS, and global longitudinal strain had correlations with LV ejection fraction (LVEF), maximum interventricular septum thickness (IVST max), and left ventricular mass index (LVMi). Torsion was mildly associated with LVEF. Conclusion: CMR-FT-derived myocardial strain and torsion provided valuable methods for evaluation of HCM and HHD. In addition, the combination of GRS and LGE (mIVS) achieved the highest diagnostic value.

KLF4 prevented angiotensin II-induced smooth muscle cell senescence by enhancing autophagic activity.

BACKGROUND: Vascular aging is an important risk factor for various cardiovascular diseases. Transcription factor krüppel-like factor 4 (KLF4) could regulate the phenotypic transformation of the vascular smooth muscle cell (VSMC) in the pathogenesis of aortic diseases. The present study aimed to explore the role and mechanism of KLF4 in angiotensin II (Ang II)-induced VSMC senescence. METHODS: The VSMC senescence mouse model was induced by sustained release of Ang II (1.0 µg/kg/min) for 4 weeks. The premature senescent VSMCs were induced by Ang II (0.1 µmol/L) for 72 h. Cellular senescence was measured by senescence-associated ß-galactosidase (SA-ß-gal) activity and p53/p16 expression. The autophagic activity was evaluated by autophagic flux and autophagic marker expression. RESULTS: The expression of KLF4 was extremely increased in abdominal aorta tissues after 1-week Ang II stimulation (p < .01) but began to decrease in later periods. Decreased expression of KLF4 was also detected in premature senescent VSMCs. Overexpression of KLF4 could enhance the antisenescence ability of VSMCs. Significantly decreased amounts of SA-ß-gal-positive cells and lower p53/p16 expression were detected in KLF4-overexpressing VSMCs (p < .01). Next, telomerase reverse transcriptase (TERT) was identified as a direct downstream target of KLF4 in VSMCs. Overexpression of KLF4 in VSMCs prevented the decreased expression of TERT under Ang II stimulation condition, which could in turn, contribute to the enhanced autophagic activity, and ultimately to the improved antisenescence ability of VSMCs. CONCLUSIONS: Our results demonstrated that overexpression of KLF4 prevented Ang II-induced VSMC senescence by promoting TERT-mediated autophagy. These findings provided novel potential targets for the prevention and therapy of vascular aging.

Synthetic biology-driven customization of functional feed resources.

To constantly supply functional feed resources (FFRs) toward meeting the rapidly growing meat demand, an efficient process alternative to traditional farming is required. Fermentation of synthetic microorganisms serves as an emerging solution, necessitating the coordination of (i) microorganism customization, (ii) product processing, and (iii) effect evaluation using animal experiments.

MicroRNA-22 promoted osteogenic differentiation of valvular interstitial cells by inhibiting CAB39 expression during aortic valve calcification.

Calcific aortic valve disease (CAVD) is a common valve disease characterized by the fibro-calcific remodeling of the aortic valves, which is an actively regulated process involving osteogenic differentiation of valvular interstitial cells (VICs). MicroRNA (miRNA) is an essential regulator in diverse biological processes in cells. The present study aimed to explore the role and mechanism of miR-22 in the osteogenic differentiation of VICs. The expression profile of osteogenesis-related miRNAs was first detected in aortic valve tissue from CAVD patients (n = 33) and healthy controls (n = 12). miR-22 was highly expressed in calcified valve tissues (P < 0.01), and the expression was positively correlated with the expression of OPN (rs = 0.820, P < 0.01) and Runx2 (rs = 0.563, P < 0.01) in VICs isolated from mild or moderately calcified valves. The sustained high expression of miR-22 was also validated in an in-vitro VICs osteogenic model. Adenovirus-mediated gain-of-function and loss-of-function experiments were then performed. Overexpression of miR-22 significantly accelerated the calcification process of VICs, manifested by significant increases in calcium deposition, alkaline phosphate activity, and expression of osteoblastic differentiation markers. Conversely, inhibition of miR-22 significantly negated the calcification process. Subsequently, calcium-binding protein 39 (CAB39) was identified as a target of miR-22. Overexpression of miR-22 significantly reduced the expression of CAB39 in VICs, leading to decreased catalytic activity of the CAB39-LKB1-STRAD complex, which, in turn, exacerbated changes in the AMPK-mTOR signaling pathway, and ultimately accelerated the calcification process. In addition, ROS generation and autophagic activity during VIC calcification were also regulated by miR-22/CAB39 pathway. These results indicate that miR-22 is an important accelerator of the osteogenic differentiation of VICs, and a potential therapeutic target in CAVD.

Engineering precursor supply for the high-level production of ergothioneine in Saccharomyces cerevisiae.

Ergothioneine (ERG) is an unusual sulfur-containing amino acid. It is a potent antioxidant, which shows great potential for ameliorating neurodegenerative and cardiovascular diseases. L-ergothioneine is rare in nature, with mushrooms being the primary dietary source. The chemical synthesis process is complex and expensive. Alternatively, ERG can be produced by fermentation of recombinant microorganisms engineered for ERG overproduction. Here, we describe the engineering of S. cerevisiae for high-level ergothioneine production on minimal medium with glucose as the only carbon source. To this end, metabolic engineering targets in different layers of the amino acid metabolism were selected based on literature and tested. Out of 28 targets, nine were found to improve ERG production significantly by 10%-51%. These targets were then sequentially implemented to generate an ergothioneine-overproducing yeast strain capable of producing 106.2 ± 2.6 mg/L ERG in small-scale cultivations. Transporter engineering identified that the native Aqr1 transporter was capable of increasing the ERG production in a yeast strain with two copies of the ERG biosynthesis pathway, but not in the strain that was further engineered for improved precursor supply. Medium optimization indicated that additional supplementation of pantothenate improved the strain's productivity further and that no supplementation of amino acid precursors was necessary. Finally, the engineered strain produced 2.39 ± 0.08 g/L ERG in 160 h (productivity of 14.95 ± 0.49 mg/L/h) in a controlled fed-batch fermentation without supplementation of amino acids. This study paves the way for the low-cost fermentation-based production of ergothioneine.

[Artificial bioconversion of carbon dioxide].

Utilization of carbon dioxide (CO2) is a huge challenge for global sustainable development. Biological carbon fixation occurs in nature, but the low energy efficiency and slow speed hamper its commercialization. Physical-chemical carbon fixation is efficient, but relies on high energy consumption and often generates unwanted by-products. Combining the advantages of biological, physical and chemical technologies for efficient utilization of CO2 remains to be an urgent scientific and technological challenge to be addressed. Here, based on the development of Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences in the past decade, we summarize the important progress in the design and construction of functional parts, pathways and systems for artificial bioconversion of carbon dioxide, including the breakthrough on the artificial synthesis of starch from CO2. Moreover, we prospect how to further develop the technologies for artificial bioconversion of carbon dioxide. These progress and perspectives provide new insight for achieving the goal of "carbon peaking and carbon neutrality".

Shared gene characteristics and molecular mechanisms of macrophages M1 polarization in calcified aortic valve disease.

Background: CAVD is a common cardiovascular disease, but currently there is no drug treatment. Therefore, it is urgent to find new and effective drug therapeutic targets. Recent evidence has shown that the infiltration of M1 macrophages increased in the calcified aortic valve tissues, but the mechanism has not been fully elucidated. The purpose of this study was to explore the shared gene characteristics and molecular mechanisms of macrophages M1 polarization in CAVD, in order to provide a theoretical basis for new drugs of CAVD. Methods: The mRNA datasets of CAVD and M1 polarization were downloaded from Gene Expression Omnibus (GEO) database. R language, String, and Cytoscape were used to analyze the functions and pathways of DEGs and feature genes. Immunohistochemical staining and Western Blot were performed to verify the selected hub genes. Results: CCR7 and GZMB were two genes appeared together in hub genes of M1-polarized and CAVD datasets that might be involved in the process of CAVD and macrophages M1 polarization. CCR7 and CD86 were significantly increased, while CD163 was significantly decreased in the calcified aortic valve tissues. The infiltration of M1 macrophages was increased, on the contrary, the infiltration of M2 macrophages was decreased in the calcified aortic valve tissues. Conclusion: This study reveals the shared gene characteristics and molecular mechanisms of CAVD and macrophages M1 polarization. The hub genes and pathways we found may provide new ideas for the mechanisms underlying the occurrence of M1 polarization during CAVD process.

Aspirin relieves the calcification of aortic smooth muscle cells by enhancing the heat shock response.

CONTEXT: Vascular calcification is a major complication of chronic renal failure, which has been identified as an active process partly driven by osteogenic transition of vascular smooth muscle cells (VSMCs). Aspirin could prevent cardiomyocyte damage by inducing heat shock response. OBJECTIVE: This study investigates the effect of aspirin on alleviating VSMC calcification. MATERIALS AND METHODS: An in vitro VSMC calcification model was established by 10-day calcification induction in osteogenic medium. VSMCs were grouped as following: control group (normal medium), calcified group (osteogenic medium) and treated group (osteogenic medium with 1 or 4 mmol/L aspirin). VSMC calcification was evaluated by calcified nodules formation, intracellular calcium concentration and osteoblastic marker (OPN and Runx2) expression. RESULTS: After 10-day culture, the intracellular calcium concentration in calcified group was significantly higher than that in control group (1.16 ± 0.04 vs. 0.14 ± 0.01 µg/mg, p < 0.01), but significantly reduced in 1 mmol/L aspirin treated group (0.74 ± 0.05 µg/mg, p < 0.01), and 4 mmol/L aspirin treated group (0.93 ± 0.03 µg/mg, p < 0.01). The elevated expression of OPN and Runx2 induced by osteogenic medium was significantly relieved after 1 or 4 mmol/L aspirin treatment. The expression of HSF1, HSP70 and HSP90 was decreased in calcification-induced VSMCs, but significantly increased after treatment of aspirin. Furthermore, inhibition of HSP70 (or HSP90) by small-molecule inhibitor or small interfering RNA could partially abolish the anti-calcification effect of aspirin, proved by the changes of intracellular calcium concentration and osteoblastic marker expression. DISCUSSION AND CONCLUSIONS: Aspirin could relieve the calcification of VSMCs partially through HSP70- or HSP90-mediated heat shock response. These findings expanded the understanding of aspirin pharmacology, and imply that local induction expression of HSPs might be a potential therapeutic strategy for the prevention and therapy of vascular calcification.