Non-contact assessment of cardiac physiology using FO-MVSS-based ballistocardiography: a promising approach for heart failure evaluation.

Continuous monitoring of cardiac motions has been expected to provide essential cardiac physiology information on cardiovascular functioning. A fiber-optic micro-vibration sensing system (FO-MVSS) makes it promising. This study aimed to explore the correlation between Ballistocardiography (BCG) waveforms, measured using an FO-MVSS, and myocardial valve activity during the systolic and diastolic phases of the cardiac cycle in participants with normal cardiac function and patients with congestive heart failure (CHF). A high-sensitivity FO-MVSS acquired continuous BCG recordings. The simultaneous recordings of BCG and electrocardiogram (ECG) signals were obtained from 101 participants to examine their correlation. BCG, ECG, and intracavitary pressure signals were collected from 6 patients undergoing cardiac catheter intervention to investigate BCG waveforms and cardiac cycle phases. Tissue Doppler imaging (TDI) measured cardiac time intervals in 51 participants correlated with BCG intervals. The BCG recordings were further validated in 61 CHF patients to assess cardiac parameters by BCG. For heart failure evaluation machine learning was used to analyze BCG-derived cardiac parameters. Significant correlations were observed between cardiac physiology parameters and BCG's parameters. Furthermore, a linear relationship was found betwen IJ amplitude and cardiac output (r = 0.923, R2 = 0.926, p < 0.001). Machine learning techniques, including K-Nearest Neighbors (KNN), Decision Tree Classifier (DTC), Support Vector Machine (SVM), Logistic Regression (LR), Random Forest (RF), and XGBoost, respectively, demonstrated remarkable performance. They all achieved average accuracy and AUC values exceeding 95% in a five-fold cross-validation approach. We establish an electromagnetic-interference-free and non-contact method for continuous monitoring of the cardiac cycle and myocardial contractility and measure the different phases of the cardiac cycle. It presents a sensitive method for evaluating changes in both cardiac contraction and relaxation in the context of heart failure assessment.

Transcriptome analysis reveals the mechanism of pyroptosis-related genes in septic cardiomyopathy.

Background: Septic cardiomyopathy (SC) is characterized by myocardial dysfunction caused by sepsis and constitutes one of the serious complications of sepsis. Pyroptosis is a unique proinflammatory programmed cell death process. However, the role of pyroptosis in the development of SC remains unclear, and further study is required. The purpose of this study is to identify pyroptosis-related genes (PRGs) in SC and explore the mechanism of pyroptosis involved in the regulation of SC formation and progression. Methods: Differential expression analysis and enrichment analysis were performed on the SC-related dataset GSE79962 to identify differentially expressed genes (DEGs). PRGs were screened by intersecting genes associated with pyroptosis in previous studies with the DEGs obtained from GSE79962. The expression pattern of them was studied based on their raw expression data. Additionally, corresponding online databases were used to predict miRNAs, transcription factors (TFs) and therapeutic agents of PRGs. Lipopolysaccharide (LPS)-induced cell damage models in H9C2 and AC16 cell lines were constructed, cell activity was detected by CCK-8 and cell pyroptosis were detected by Hoechst33342/PI staining. Furthermore, these PRGs were verified in the external datasets (GSE53007 and GSE142615) and LPS-induced cell damage model. Finally, the effect of siRNA-mediated PRGs knockdown on the pyroptosis phenotype was examined. Results: A total of 1,206 DEGs were screened, consisting of 663 high-expressed genes and 543 low-expressed genes. Among them, ten PRGs (SOD2, GJA1, TIMP3, TAP1, TIMP1, NOD1, TP53, CPTP, CASP1 and SAT1) were identified, and they were mainly enriched in "Pyroptosis", "Ferroptosis", "Longevity regulating pathway", and "NOD-like receptor signaling pathway". A total of 147 miRNAs, 31 TFs and 13 therapeutic drugs were predicted targeting the PRGs. The expression trends of SOD2 were confirmed in both the external datasets and LPS-induced cell damage models. Knockdown of SOD2 induced increased pyroptosis in the AC16 LPS-induced cell damage model. Conclusions: In this study, we demonstrated that SOD2 is highly expressed in both the SC and LPS-induced cell damage models. Knockdown of SOD2 led to a significant increase in pyroptosis in the AC16 LPS-induced cell damage model. These findings suggest that SOD2 may serve as a potential target for the diagnosis and treatment of SC.

Protein O-GlcNAcylation in multiple immune cells and its therapeutic potential.

O-GlcNAcylation is a post-translational modification of proteins that involves the addition of O-GlcNAc to serine or threonine residues of nuclear or cytoplasmic proteins, catalyzed by O-GlcNAc transferase (OGT). This modification is highly dynamic and can be reversed by O-GlcNAcase (OGA). O-GlcNAcylation is widespread in the immune system, which engages in multiple physiologic and pathophysiologic processes. There is substantial evidence indicating that both the hexosamine biosynthesis pathway (HBP) and O-GlcNAcylation are critically involved in regulating immune cell function. However, the precise role of O-GlcNAcylation in the immune system needs to be adequately elucidated. This review offers a thorough synopsis of the present research on protein O-GlcNAcylation, accentuating the molecular mechanisms that control immune cells' growth, maturation, and performance via this PTM.

Immune Cell Infiltration Analysis Based on Bioinformatics Reveals Novel Biomarkers of Coronary Artery Disease.

Background: Coronary artery disease (CAD) is a multifactorial immune disease, but research into the specific immune mechanism is still needed. The present study aimed to identify novel immune-related markers of CAD. Methods: Three CAD-related datasets (GSE12288, GSE98583, GSE113079) were downloaded from the Gene Expression Integrated Database. Gene ontology annotation, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis and weighted gene co-expression network analysis were performed on the common significantly differentially expressed genes (DEGs) of these three data sets, and the most relevant module genes for CAD obtained. The immune cell infiltration of module genes was evaluated with the CIBERSORT algorithm, and characteristic genes accompanied by their diagnostic effectiveness were screened by the machine-learning algorithm least absolute shrinkage and selection operator (LASSO) regression analysis. The expression levels of characteristic genes were evaluated in the peripheral blood mononuclear cells of CAD patients and healthy controls for verification. Results: A total of 204 upregulated and 339 downregulated DEGs were identified, which were mainly enriched in the following pathways: "Apoptosis", "Th17 cell differentiation", "Th1 and Th2 cell differentiation", "Glycerolipid metabolism", and "Fat digestion and absorption". Five characteristic genes, LMAN1L, DOK4, CHFR, CEL and CCDC28A, were identified by LASSO analysis, and the results of the immune cell infiltration analysis indicated that the proportion of immune infiltrating cells (activated CD8 T cells and CD56 DIM natural killer cells) in the CAD group was lower than that in the control group. The expressions of CHFR, CEL and CCDC28A in the peripheral blood of the healthy controls and CAD patients were significantly different. Conclusion: We identified CHFR, CEL and CCDC28A as potential biomarkers related to immune infiltration in CAD based on public data sets and clinical samples. This finding will contribute to providing a potential target for early noninvasive diagnosis and immunotherapy of CAD.

Cardiac Mesenchymal Stem Cells Promote Fibrosis and Remodeling in Heart Failure: Role of PDGF Signaling.

Heart failure (HF) is characterized by progressive fibrosis. Both fibroblasts and mesenchymal stem cells (MSCs) can differentiate into pro-fibrotic myofibroblasts. MSCs secrete and express platelet-derived growth factor (PDGF) and its receptors. We hypothesized that PDGF signaling in cardiac MSCs (cMSCs) promotes their myofibroblast differentiation and aggravates post-myocardial infarction left ventricular remodeling and fibrosis. We show that cMSCs from failing hearts post-myocardial infarction exhibit an altered phenotype. Inhibition of PDGF signaling in vitro inhibited cMSC-myofibroblast differentiation, whereas in vivo inhibition during established ischemic HF alleviated left ventricular remodeling and function, and decreased myocardial fibrosis, hypertrophy, and inflammation. Modulating cMSC PDGF receptor expression may thus represent a novel approach to limit pathologic cardiac fibrosis in HF.

Kidney-Specific Klotho Gene Deletion Causes Aortic Aneurysm via Hyperphosphatemia.

[Figure: see text].

Tryptophan-Derived 3-Hydroxyanthranilic Acid Contributes to Angiotensin II-Induced Abdominal Aortic Aneurysm Formation in Mice In Vivo.

BACKGROUND: Abnormal amino acid metabolism is associated with vascular disease. However, the causative link between dysregulated tryptophan metabolism and abdominal aortic aneurysm (AAA) is unknown. METHODS: Indoleamine 2,3-dioxygenase (IDO) is the first and rate-limiting enzyme in the kynurenine pathway of tryptophan metabolism. Mice with deficiencies in both apolipoprotein e (Apoe) and IDO (Apoe-/-/IDO-/-) were generated by cross-breeding IDO-/- mice with Apoe-/- mice. RESULTS: The acute infusion of angiotensin II markedly increased the incidence of AAA in Apoe-/- mice, but not in Apoe-/-/IDO-/- mice, which presented decreased elastic lamina degradation and aortic expansion. These features were not altered by the reconstitution of bone marrow cells from IDO+/+ mice. Moreover, angiotensin II infusion instigated interferon-γ, which induced the expression of IDO and kynureninase and increased 3-hydroxyanthranilic acid (3-HAA) levels in the plasma and aortas of Apoe-/- mice, but not in IDO-/- mice. Both IDO and kynureninase controlled the production of 3-HAA in vascular smooth muscle cells. 3-HAA upregulated matrix metallopeptidase 2 via transcription factor nuclear factor-κB. Furthermore, kynureninase knockdown in mice restrained 3-HAA, matrix metallopeptidase 2, and resultant AAA formation by angiotensin II infusion. Intraperitoneal injections of 3-HAA into Apoe-/- and Apoe-/-/IDO-/- mice for 6 weeks increased the expression and activity of matrix metallopeptidase 2 in aortas without affecting metabolic parameters. Finally, human AAA samples had stronger staining with the antibodies against 3-HAA, IDO, and kynureninase than those in adjacent nonaneurysmal aortic sections of human AAA samples. CONCLUSIONS: These data define a previously undescribed causative role for 3-HAA, which is a product of tryptophan metabolism, in AAA formation. Furthermore, these findings suggest that 3-HAA reduction may be a new target for treating cardiovascular diseases.

Aberrant NRP-1 expression serves as predicator of metastatic endometrial and lung cancers.

Neuropilin-1 (NRP-1) has emerged as an important driver of tumor-promoting phenotypes of human malignancies. However, incomplete knowledge exists as to how this single-pass transmembrane receptor mediates pleiotropic tumor-promoting functions. The purpose of this study was to evaluate NRP-1 expression and metastatic properties in 94 endometrial cancer and matching serum specimens and in a lung cancer cell line. We found that NRP-1 expression significantly correlated with increased tumoral expression of vascular endothelial growth factor 2 (VEGFR2) and serum levels of hepatocyte growth factor (HGF) and cell growth-stimulating factor (C-GSF). Tumoral NRP-1 also was positively associated with expression of NEDD9, a pro-metastatic protein. In the highly metastatic lung cancer cell line (H1792), stable LKB1 depletion caused increased migration in vitro and accentuated NRP-1 and NEDD9 expression in vivo. Our findings demonstrate that perturbed expression of these targets correlate with metastatic potential of endometrial and lung tumors, providing clinically-relevant biomarker applications for diagnostic and therapeutic targeting.

Tryptophan-kynurenine pathway is dysregulated in inflammation, and immune activation.

The kynurenine (Kyn) pathway is the major route for tryptophan (Trp) metabolism, and it contributes to several fundamental biological processes. Trp is constitutively oxidized by tryptophan 2, 3-dioxygenase in liver cells. In other cell types, it is catalyzed by an alternative inducible indoleamine-pyrrole 2, 3-dioxygenase (IDO) under certain pathophysiological conditions, which consequently increases the formation of Kyn metabolites. IDO is up-regulated in response to inflammatory conditions as a novel marker of immune activation in early atherosclerosis. Besides, IDO and the IDO-related pathway are important mediators of the immunoinflammatory responses in advanced atherosclerosis. In particular, Kyn, 3-hydroxykynurenine, and quinolinic acid are positively associated with inflammation, oxidative stress (SOX), endothelial dysfunction, and carotid artery intima-media thickness values in end-stage renal disease patients. Moreover, IDO is a potential novel contributor to vessel relaxation and metabolism in systemic infections, which is also activated in acute severe heart attacks. The Kyn pathway plays a key role in the increased prevalence of cardiovascular disease by regulating inflammation, SOX, and immune activation.

Chemokine receptors CXCR2 and CX3CR1 differentially regulate functional responses of bone-marrow endothelial progenitors during atherosclerotic plaque regression.

AIMS: Atherosclerosis manifests itself as arterial plaques, which lead to heart attacks or stroke. Treatments supporting plaque regression are therefore aggressively pursued. Studies conducted in models in which hypercholesterolaemia is reversible, such as the Reversa mouse model we have employed in the current studies, will be instrumental for the development of such interventions. Using this model, we have shown that advanced atherosclerosis regression occurs when lipid lowering is used in combination with bone-marrow endothelial progenitor cell (EPC) treatment. However, it remains unclear how EPCs home to regressing plaques and how they augment atherosclerosis reversal. Here we identify molecules that support functional responses of EPCs during plaque resolution. METHODS AND RESULTS: Chemokines CXCL1 and CX3CL1 were detected in the vascular wall of atheroregressing Reversa mice, and their cognate receptors CXCR2 and CX3CR1 were observed on adoptively transferred EPCs in circulation. We tested whether CXCL1-CXCR2 and CX3CL1-CX3CR1 axes regulate functional responses of EPCs during plaque reversal. We show that pharmacological inhibition of CXCR2 or CX3CR1, or genetic inactivation of these two chemokine receptors interfered with EPC-mediated advanced atherosclerosis regression. We also demonstrate that CXCR2 directs EPCs to regressing plaques while CX3CR1 controls a paracrine function(s) of these cells. CONCLUSION: CXCR2 and CX3CR1 differentially regulate EPC functional responses during atheroregression. Our study improves understanding of how chemokines and chemokine receptors regulate plaque resolution, which could determine the effectiveness of interventions reducing complications of atherosclerosis.

Gefitinib-mediated reactive oxygen specie (ROS) instigates mitochondrial dysfunction and drug resistance in lung cancer cells.

Therapeutic benefits offered by tyrosine kinase inhibitors (TKIs), such as gefitinib (Iressa) and erlotinib (Tarceva), are limited due to the development of resistance, which contributes to treatment failure and cancer-related mortality. The aim of this study was to elucidate mechanistic insight into cellular perturbations that accompany acquired gefitinib resistance in lung cancer cells. Several lung adenocarcinoma (LAD) cell lines were screened to characterize epidermal growth factor receptor (EGFR) expression and mutation profile. To circumvent intrinsic variations between cell lines with respect to response to drug treatments, we generated gefitinib-resistant H1650 clone by long-term, chronic culture under gefitinib selection of parental cell line. Isogenic cells were analyzed by microarray, Western blot, flow cytometry, and confocal and transmission electron microscope. We observed that although chronic gefitinib treatment provided effective action against its primary target (aberrant EGFR activity), secondary effects resulted in increased cellular reactive oxygen species (ROS). Gefitinib-mediated ROS correlated with epithelial-mesenchymal transition, as well as striking perturbation of mitochondrial morphology and function. However, gefitinib treatment in the presence of ROS scavenger provided a partial rescue of mitochondrial aberrations. Furthermore, withdrawal of gefitinib from previously resistant clones correlated with normalized expression of epithelial-mesenchymal transition genes. These findings demonstrate that chronic gefitinib treatment promotes ROS and mitochondrial dysfunction in lung cancer cells. Antioxidants may alleviate ROS-mediated resistance.

Endothelial cell-specific liver kinase B1 deletion causes endothelial dysfunction and hypertension in mice in vivo.

BACKGROUND: Liver kinase B1 (LKB1), a tumor suppressor, is a central regulator of cell polarity and energy homeostasis. The role of LKB1 in endothelial function in vivo has not been explored. METHODS AND RESULTS: Endothelium-specific LKB1 knockout (LKB1(endo-/-)) mice were generated by cross-breeding LKB1(flox/flox) mice with VE-Cadherin-Cre mice. LKB1(endo-/-) mice exhibited hypertension, cardiac hypertrophy, and impaired endothelium-dependent relaxation. LKB1(endo-/-) endothelial cells exhibited reduced endothelial nitric oxide synthase activity and AMP kinase (a downstream enzyme of LKB1) phosphorylation at Thr172 compared with wild-type (WT) cells. In addition, the levels of caveolin-1 were higher in the endothelial cells of LKB1(endo-/-) mice, and knockdown of caveolin-1 by siRNA normalized endothelial nitric oxide synthase activity. Human antigen R bound with the adenylate-uridylate-rich elements of caveolin-1 mRNA 3' untranslated region, resulting in the increased stability of caveolin-1, and genetic knockdown of human antigen R decreased the expression of caveolin-1 in LKB1-deficient endothelial cells. Finally, adenoviral overexpression of constitutively active AMP kinase, but not green fluorescent protein, decreased caveolin-1, lowered blood pressure, and improved endothelial function in LKB1(endo-/-) mice in vivo. CONCLUSIONS: Our findings indicate that endothelial LKB1 regulates endothelial nitric oxide synthase activity, endothelial function, and blood pressure by modulating AMP kinase-mediated caveolin-1 expression.

Activation of NAD(P)H oxidase by tryptophan-derived 3-hydroxykynurenine accelerates endothelial apoptosis and dysfunction in vivo.

RATIONALE: The kynurenine (Kyn) pathway is the major route for tryptophan (Trp) metabolism in mammals. The Trp-Kyn pathway is reported to regulate several fundamental biological processes, including cell death. OBJECTIVE: The aim of this study was to elucidate the contributions and molecular mechanism of Trp-Kyn pathway to endothelial cell death. METHODS AND RESULTS: Endogenous reactive oxygen species, endothelial cell apoptosis, and endothelium-dependent and endothelium-independent vasorelaxation were measured in aortas of wild-type mice or mice deficient for nicotinamide adenine dinucleotide phosphate [NAD(P)H] oxidase subunits (p47(phox) or gp91(phox)) or indoleamine-pyrrole 2,3-dioxygenase 1 with or without angiotensin (Ang) II infusion. As expected, AngII increased plasma levels of Kyn- and 3-hydroxykynurenine-modified proteins in endothelial cells in vivo. Consistent with this, AngII markedly increased the expression of indoleamine-pyrrole 2,3-dioxygenase in parallel with increased expression of interferon-γ. Furthermore, in wild-type mice, AngII significantly increased oxidative stress, endothelial cell apoptosis, and endothelial dysfunction. These effects of AngII infusion were significantly suppressed in mice deficient for p47(phox), gp91(phox), or indoleamine-pyrrole 2,3-dioxygenase 1, suggesting that AngII-induced enhancement of Kynurenines via NAD(P)H oxidase-derived oxidants causes endothelial cell apoptosis and dysfunction in vivo. Furthermore, interferon-γ neutralization eliminates AngII-increased superoxide products and endothelial apoptosis by inhibiting AngII-induced Kynurenines generation, suggesting that AngII-activated Kyn pathway is interferon-γ-dependent. Mechanistically, we found that AngII-enhanced 3-hydroxykynurenine promoted the generation of NAD(P)H oxidase-mediated superoxide anions by increasing the translocation and membrane assembly of NAD(P)H oxidase subunits in endothelial cells, resulting in accelerated apoptosis and consequent endothelial dysfunction. CONCLUSIONS: Kyn pathway activation accelerates apoptosis and dysfunction of the endothelium by upregulating NAD(P)H-derived superoxide.

[Visfatin upregulates MMP-2 and MMP-9 expressions in human monocytes through activating NF-kappaB].

OBJECTIVE: To investigate the effects of visfatin on the MMP-2 and MMP-9 expressions in human monocytes and related mechanisms. METHODS: Human monocytes were isolated from blood, the expressions of MMP-2 and MMP-9 at mRNA and protein levels were detected in visfatin stimulated monocytes (0, 100, 200, 400 ng/ml) in the absence and presence of NF-kappaB inhibitor specific Bay11-7082 by Realtime PCR or Western blot, the MMP-2 and MMP-9 enzyme activity in the culture media was also detected by Gelatin Zymography. The NF-kappaB protein level and NF-kappaBp65 expression in visfatin stimulated cells were measured by Western blot and ELISA, respectively. RESULTS: Visfatin upregulated MMP-2 and MMP-9 expressions in human monocytes in a dose dependent manner. After treatment with visfatin 400 ng/ml for 24 h, comparing with the free visfatin treatment, the protein expressions of MMP-2 and MMP-9 were up-regulated to 1.644 +/- 0.052 and 3.578 +/- 0.081 (all P < 0.001); the enzyme activities of MMP-2 and MMP-9 were enhanced by 1.661 +/- 0.036 (P < 0.001) and 1.662 +/- 0.100 (P < 0.001). NF-kappaB was also activated in these cells by visfatin and these effects could be significantly attenuated by Bay11-7082. Visfatin induced a dose-dependent (100 - 400 ng) increase of NF-kappaBp65 nuclear translocation from 0.763 +/- 0.056 to 1.290 +/- 0.065 at 100 and 400 ng/ml, comparing with free visfatin treatment 0.467 +/- 0.046 (all P < 0.05). Bay11-7082 decreased the protein expression of MMP-2 and MMP-9 to 1.183 +/- 0.030 and 2.024 +/- 0.056 (all P < 0.001 comparing with 400 ng/ml visfatin treatment). CONCLUSION: Visfatin enhanced the expression and activity of MMP-2 and MMP-9 in human monocytes via activating NF-kappaB signaling pathway.