Proximal telomeric decompaction due to telomere shortening drives FOXC1-dependent myocardial senescence.

Telomeres, TTAGGGn DNA repeat sequences located at the ends of eukaryotic chromosomes, play a pivotal role in aging and are targets of DNA damage response. Although we and others have demonstrated presence of short telomeres in genetic cardiomyopathic and heart failure cardiomyocytes, little is known about the role of telomere lengths in cardiomyocyte. Here, we demonstrate that in heart failure patient cardiomyocytes, telomeres are shortened compared to healthy controls. We generated isogenic human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) with short telomeres (sTL-CMs) and normal telomeres (nTL-CMs) as model. Compared to nTL-CMs, short telomeres result in cardiac dysfunction and expression of senescent markers. Using Hi-C and RNASeq, we observe that short telomeres induced TAD insulation decrease near telomeric ends and this correlated with a transcription upregulation in sTL-CMs. FOXC1, a key transcription factor involved in early cardiogenesis, was upregulated in sTL-CMs and its protein levels were negatively correlated with telomere lengths in heart failure patients. Overexpression of FOXC1 induced hiPSC-CM aging, mitochondrial and contractile dysfunction; knockdown of FOXC1 rescued these phenotypes. Overall, the work presented demonstrate that increased chromatin accessibility due to telomere shortening resulted in the induction of FOXC1-dependent expression network responsible for contractile dysfunction and myocardial senescence.

Trisomy 21-driven metabolite alterations are linked to cellular injuries in Down syndrome.

Down syndrome (DS) arises from a genetic anomaly characterized by an extra copy of chromosome 21 (exCh21). Despite high incidence of congenital diseases among DS patients, direct impacts of exCh21 remain elusive. Here, we established a robust DS model harnessing human-induced pluripotent stem cells (hiPSCs) from mosaic DS patient. These hiPSC lines encompassed both those with standard karyotype and those carrying an extra copy of exCh21, allowing to generate isogenic cell lines with a consistent genetic background. We unraveled that exCh21 inflicted disruption upon the cellular transcriptome, ushering in alterations in metabolic processes and triggering DNA damage. The impact of exCh21 was also manifested in profound modifications in chromatin accessibility patterns. Moreover, we identified two signature metabolites, 5-oxo-ETE and Calcitriol, whose biosynthesis is affected by exCh21. Notably, supplementation with 5-oxo-ETE promoted DNA damage, in stark contrast to the protective effect elicited by Calcitriol against such damage. We also found that exCh21 disrupted cardiogenesis, and that this impairment could be mitigated through supplementation with Calcitriol. Specifically, the deleterious effects of 5-oxo-ETE unfolded in the form of DNA damage induction and the repression of cardiogenesis. On the other hand, Calcitriol emerged as a potent activator of its nuclear receptor VDR, fostering amplified binding to chromatin and subsequent facilitation of gene transcription. Our findings provide a comprehensive understanding of exCh21's metabolic implications within the context of Down syndrome, offering potential avenues for therapeutic interventions for Down syndrome treatment.

MicroRNA-338-3p as a therapeutic target in cardiac fibrosis through FGFR2 suppression.

BACKGROUND: The development of cardiac fibrosis involves the activation of cardiac fibroblasts (CFs) and their differentiation into myofibroblasts, which leads to the disruption of the extracellular matrix network. In the past few years, microRNAs (miRNA) have been described as potential targets for treating cardiac diseases. Although miR-338-3p has been shown to participate in the development of carcinoma, whether it affects cardiac fibrosis is unclear. METHODS: We examined the expression profiles of microRNAs in left ventricular samples of heart failure mice established by thoracic aortic constriction (TAC). Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the expression of miR-338-3p. CCK-8 assay/Transwell migration assay was used to measure the proliferation rate/migration of CFs. Luciferase reporter gene assay was used to test the binding between miR-338-3p and FGFR2. RESULTS: This study demonstrated that miR-338-3p was significantly decreased in thoracic aortic constriction mice. Cardiac miR-338-3p amounts were also reduced in patients with dilated cardiomyopathy (DCM). Interestingly, miR-338-3p overexpression inhibited α-SMA, COL1A1, and COL3A1 expression, as well as cell proliferation and migration in CFs. Bioinformatics analysis and dual-luciferase reporter assays revealed FGFR2 was targeted by miR-338-3p, whose antifibrotic effect could be alleviated by overexpression of FGFR2. Moreover, in DCM cases, serum miR-338-3p levels were markedly elevated in individuals with worse outcomes. CONCLUSIONS: The present study provides evidence that miR-338-3p suppresses cardiac fibroblast activation, proliferation, and migration by directly targeting FGFR2 in mice. Besides, serum miR-338-3p might constitute a potential prognostic biomarker of dilated cardiomyopathy.

PGAM1 deficiency ameliorates myocardial infarction remodeling by targeting TGF-ß via the suppression of inflammation, apoptosis and fibrosis.

Myocardial ischemia-reperfusion (MIR) represents critical challenge for the treatment of acute myocardial infarction diseases. Presently, identifying the molecular basis revealing MIR progression is scientifically essential and may provide effective therapeutic strategies. Phosphoglycerate mutase 1 (PGAM1) is a key aerobic glycolysis enzyme, and exhibits critical role in mediating several biological events, such as energy production and inflammation. However, whether PGAM1 can affect MIR is unknown. Here we showed that PGAM1 levels were increased in murine ischemic hearts. Mice with cardiac knockout of PGAM1 were resistant to MIR-induced heart injury, evidenced by the markedly reduced infarct volume, improved cardiac function and histological alterations in cardiac sections. In addition, inflammatory response, apoptosis and fibrosis in hearts of mice with MIR operation were significantly alleviated by the cardiac deletion of PGAM1. Mechanistically, the activation of nuclear transcription factor κB (NF-κB), p38, c-Jun NH2-terminal kinase (JNK) and transforming growth factor ß (TGF-ß) signaling pathways were effectively abrogated in MI-operated mice with specific knockout of PGAM1 in hearts. The potential of PGAM1 suppression to inhibit inflammatory response, apoptosis and fibrosis were verified in the isolated cardiomyocytes and fibroblasts treated with oxygen-glucose deprivation reperfusion (OGDR) and TGF-ß, respectively. Importantly, PGAM1 directly interacted with TGF-ß to subsequently mediate inflammation, apoptosis and collagen accumulation, thereby achieving its anti-MIR action. Collectively, these findings demonstrated that PGAM1 was a positive regulator of myocardial infarction remodeling due to its promotional modulation of TGF-ß signaling, indicating that PGAM1 may be a promising therapeutic target for MIR treatment.

FLNC and MYLK2 Gene Mutations in a Chinese Family with Different Phenotypes of Cardiomyopathy.

Mutations in the sarcomeric protein filamin C (FLNC) gene have been linked to hypertrophic cardiomyopathy (HCM), as they have been determined to increase the risk of ventricular arrhythmia and sudden death. Thus, in this study, we identified a novel missense mutation of FLNC in a Chinese family with HCM, and, interestingly, a second novel truncating mutation of MYLK2 was discobered in one family member with different phenotype.We performed whole-exome sequencing in a Chinese family with HCM of unknown cause. To determine and confirm the function of a novel mutation of FLNC, we introduced the mutant and wild-type gene into AC16 cells (human cardiomyocytes): we then used western blotting to analyze the expression of FLNC in subcellular fractions, and confocal microscope to observe the subcellular distribution of the protein.As per our findings, we were able to identify a novel missense single nucleotide variant (FLNC c.G5935A [p.A1979T]) in the family, which segregates with the disease. FLNC expression levels were observed to be equivalent in both wild-type and p.A1979T cardiomyocytes. However, the expression of the mutant protein has resulted in cytoplasmic protein aggregations, in contrast to wild-type FLNC, which was distributed in the cytoplasm and did not form aggregates. Unexpectedly, a second truncating mutation, NM_033118:exon8:c.G1138T:p.E380X of the MYLK2 gene, was identified in the mother of the proband with dilated cardiomyopathy, which was not found in other subjects.We then identified the FLNC A1979T mutation as a novel pathogenic variant associated with HCM in a Chinese family as well as a second causal mutation in a family member with a distinct phenotype. The possibility that there is more than one causal mutation in cardiomyopathy warrants clinical attention, especially for patients with atypical clinical features.

A Case of a Derivative Chromosome: der(Y)t(Y;18)Pat with Congenital Abnormalities.

BACKGROUND: Chromosome reciprocal translocations are frequently occurring structural rearrangements observed in humans. Although individuals with balanced reciprocal translocations tend to be clinically normal, they have an increased risk of reproductive failure, miscarriage and abnormal phenotype.Casereport: A 14 days old neonate was found to have a 46,X,der(Y)t(Y;18)(q12;q11)pat karyotype causing multiple dysmorphisms and death within one month. The proband inherited from his father(carrier) an abnormal Y chromosome with Yq deletion of regions (q12-qter) and an 18q duplication of regions (q11-qter), resulting in a severe clinical phenotype similar to Edwards syndrome (Trisomy 18 syndrome). CONCLUSION: These findings expand our current knowledge of the mutation spectrum of Y-autosomal translocations associated with dysmorphosis.

CD36 Enhances Vascular Smooth Muscle Cell Proliferation and Development of Neointimal Hyperplasia.

Objective- Dysregulated proliferation of vascular smooth muscle cells (VSMC) plays an essential role in neointimal hyperplasia. CD36 functions critically in atherogenesis and thrombosis. We hypothesize that CD36 regulates VSMC proliferation and contributes to the development of obstructive vascular diseases. Approach and Results- We found by immunofluorescent staining that CD36 was highly expressed in human vessels with obstructive diseases. Using guidewire-induced carotid artery injury and shear stress-induced intima thickening models, we compared neointimal hyperplasia in Apoe-/-, Cd36-/- /Apoe-/-, and CD36 specifically deleted in VSMC (VSMC cd36-/-) mice. CD36 deficiency, either global or VSMC-specific, dramatically reduced injury-induced neointimal thickening. Correspondingly, carotid artery blood flow was significantly increased in Cd36-/- /Apoe-/- compared with Apoe-/- mice. In cultured VSMCs from thoracic aorta of wild-type and Cd36-/- mice, we found that loss of CD36 significantly decreased serum-stimulated proliferation and increased cell populations in S phase, suggesting that CD36 is necessary for VSMC S/G2-M-phase transition. Treatment of VSMCs with a TSR (thrombospondin type 1 repeat) peptide significantly increased wild-type, but not Cd36-/- VSMC proliferation. TSR or serum treatment significantly increased cyclin A expression in wild-type, but not in Cd36-/- VSMCs. STAT3 (signal transducer and activator of transcription), which reportedly enhances both VSMC differentiation and maturation, was higher in Cd36-/- VSMCs. CD36 deficiency significantly decreased expression of Col1A1 (type 1 collagen A1 chain) and TGF-ß1 (transforming growth factor beta 1), and increased expression of contractile proteins, including calponin 1 and smooth muscle α actin, and dramatically increased cell contraction. Conclusions- CD36 promotes VSMC proliferation via upregulation of cyclin A expression that contributes to the development of neointimal hyperplasia, collagen deposition, and obstructive vascular diseases.

Ankyrin repeat domain 1: A novel gene for cardiac septal defects.

INTRODUCTION: Cardiac septal defects account for more than 50% of congenital heart defects. Ankyrin repeat domain 1 (ANKRD1) is an important transcription factor that is mutated in multiple cardiac diseases; however, a relationship between the ANKRD1 mutation and cardiac septal defects has not been described. METHODS: We examined genetic mutations in a large family with three cardiac septal defect patients. Whole exome sequencing, bioinformatics and conservation analysis were utilized to predict the pathogenicity of candidate mutations. Dual luciferase reporter assay and nuclear localization experiments were performed to evaluate the influence of target mutation. RESULTS: A heterozygous, missense variant of ANKRD1 (MIM* 609599): NM_014391: exon6: c.C560T:p.S187F was identified at a highly conserved region. Sanger sequencing in extended family members demonstrated an incomplete inheritance model. When co-activated with NKX2.5, ANKRD1 repressed ANF expression as assessed by a dual-luciferase reporter assay, and p.S187F mutation enhanced the repressive effect (0.318 ± 0.018 versus 0.564 ± 0.048, p < 0.01). A real-time polymerase chain reaction confirmed that p.S187F mutation of ANKRD1 decreased the expression of endogenous ANF (0.85 ± 0.05 versus 0.61 ± 0.04, p < 0.01). Furthermore, nuclear localization experiments demonstrated that the mutation significantly decreased the nuclear distribution of ANKRD1. CONCLUSIONS: The present study is the first to identify the p.S187F mutant of ANKRD1, which is associated with cardiac septal defects.

Clinical application of chromosomal microarray analysis for the prenatal diagnosis of chromosomal abnormalities and copy number variations in fetuses with congenital heart disease.

OBJECTIVES: This study aimed to determine chromosomal abnormalities and copy number variations (CNVs) in fetuses with congenital heart disease (CHD) by chromosomal microarray analysis (CMA). METHODS: One hundred and ten cases with CHD detected by prenatal echocardiography were enrolled in the study; 27 cases were simple CHDs, and 83 were complex CHDs. Chromosomal microarray analysis was performed on the Affymetrix CytoScan HD platform. All annotated CNVs were validated by quantitative PCR. RESULTS: Chromosomal microarray analysis identified 6 cases with chromosomal abnormalities, including 2 cases with trisomy 21, 2 cases with trisomy 18, 1 case with trisomy 13, and 1 unusual case of mosaic trisomy 21. Pathogenic CNVs were detected in 15.5% (17/110) of the fetuses with CHDs, including 13 cases with CHD-associated CNVs. We further identified 10 genes as likely novel CHD candidate genes through gene functional enrichment analysis. We also found that pathogenic CMA results impacted the rate of pregnancy termination. CONCLUSIONS: This study shows that CMA is particularly effective for identifying chromosomal abnormalities and CNVs in fetuses with CHDs as well as having an effect on obstetrical outcomes. The elucidation of the genetic basis of CHDs will continue to expand our understanding of the etiology of CHDs.

In vitro remodeling and structural characterization of degradable polymer scaffold-based tissue-engineered vascular grafts using optical coherence tomography.

Non-destructive imaging strategies to monitor long-term cultures is essential for vascular engineering. The goal of this study is to investigate whether optical coherence tomography (OCT) can be a suitable approach to monitor the long-term remodeling process of biodegradable polymeric scaffold-based tissue-engineered vascular grafts (TEVG) after pulsatile stimulation and to observe polymeric scaffold degradation during bioreactor cultivation. In the present study, a perfusion system driven by a ventricular assist device was provided for a three-dimensional culture system as a pulsatile force. We characterized the structural features of wall thickness and polyglycolic acid degradation based on optical signal attenuation using catheter-based OCT. Scanning electron microscopy confirmed morphological changes. Also, polymer degradation and the detection of different types of collagen was visualized after 4 weeks of culture by means of polarized microscopy. Findings on OCT imaging correlated with those on histological examination and revealed the effects of pulsatile stimulation on the development of engineered vessels. This finding demonstrated that real-time imaging with OCT may be a promising tool for monitoring the growth and remodeling characterization of TEVG and provide a basis to promote the ideal and long-term culture of vascular tissue engineering.

Population pharmacokinetics and safety of eptifibatide in healthy Chinese volunteers and simulations on the dose regimens approved for a Western population.

OBJECTIVE: This study was designed to evaluate the pharmacokinetics (PK) and safety of eptifibatide in healthy Chinese volunteers and provide information for the further study in the Chinese population. METHODS: 30 healthy volunteers (15 male) were enrolled in the study and divided into three dose groups (45 µg x kg⁻¹, 90 µg x kg⁻¹, and 180 µg x kg⁻¹). Plasma and urine samples were drawn after one single-bolus administration and measured by LC-MS/MS. The plasma and urine data were analyzed simultaneously by the population approach using the NONMEM software and evaluated by the visual predicted check (VPC) and bootstraping. The PK profiles of dose regimens approved for a Western population in the Chinese population were simulated. RESULTS: A two-compartment model adequately described the PK profiles of eptifibatide. The clearance (CL) and the distribution volume (V1) of the central compartment were 0.128 L x h⁻¹ x kg⁻¹ and 0.175 L x kg⁻¹, respectively. The clearance (Q) and V2of the peripheral compartment were 0.0988 L x h⁻¹ x kg⁻¹ and 0.147 L x kg⁻¹, respectively. The elimination fraction from plasma to urine (F0) was 17.2%. No covariates were found to have a significant effect. Inter-individual variabilites were all within 33.9%. The VPC plots and bootstrap results indicated good precision and prediction of the model. The simulations of the approved regimens in the Chinese population showed much lower steady-state concentrations than the target concentration obtained from the Western clinical trials. No severe safety events were found in this study. CONCLUSIONS: The PK model of eptifibatide was established and could provide PK information for further studies in the Chinese population.

Genetic association analyses highlight apolipoprotein B as a determinant of chronic kidney disease in patients with type 2 diabetes.

BACKGROUND: Blood lipid levels were associated with chronic kidney disease (CKD) in patients with type 2 diabetes (T2D), but the genetic basis and causal nature remains unclear. OBJECTIVE: This study aimed to investigate the relationships of lipids and their fractions with CKD in patients with T2D. METHODS: Our prospective analysis involved 8,607 White participants with T2D but no CKD at baseline from the UK Biobank. Five common lipid traits were included as exposures. Weighted genetic risk scores (GRSs) for these lipid traits were developed. The causal associations between lipid traits, as well as lipid fractions, and CKD were explored using linear or nonlinear Mendelian randomization (MR). The 10-year predicted probabilities of CKD were evaluated via integrating MR and Cox models. RESUTLS: Higher GRS of apolipoprotein B (ApoB) was associated with an increased CKD risk (HR[95 % CI]:1.07[1.02,1.13] per SD;P = 0.008) after adjusting for potential confounders. Linear MR indicated a positive association between genetically predicted ApoB levels and CKD (HR[95 % CI]:1.53[1.12,2.09];P = 0.008), but no evidence of associations was found between other lipid traits and CKD in T2D. Regarding 12 ApoB-contained lipid fractions, a significant causal association was found between medium very-low-density lipoprotein particles and CKD (HR[95 % CI]:1.16[1.02,1.32];P = 0.020). Nonlinear MR did not support nonlinearity in these causal associations. The 10-year probability curve showed that ApoB levels was positively associated with the risk of CKD in patients with T2D. CONCLUSION: Lower ApoB levels were causally associated with a reduced risk of CKD in patients with T2D, positioning ApoB as a potential therapeutic target for CKD prevention in this population.

Transcriptome analysis reveals EBF1 ablation-induced injuries in cardiac system.

Rationale: Regulatory processes of transcription factors (TFs) shape heart development and influence the adult heart's response to stress, contributing to cardiac disorders. Despite their significance, the precise mechanisms underpinning TF-mediated regulation remain elusive. Here, we identify that EBF1, as a TF, is highly expressed in human heart tissues. EBF1 is reported to be associated with human cardiovascular disease, but its roles are unclear in heart. In this study, we investigated EBF1 function in cardiac system. Methods: RNA-seq was utilized to profile EBF1 expression patterns. CRISPR/Cas9 was utilized to knock out EBF1 to investigate its effects. Human pluripotent stem cells (hPSCs) differentiated into cardiac lineages were used to mimic cardiac development. Cardiac function was evaluated on mouse model with Ebf1 knockout by using techniques such as echocardiography. RNA-seq was conducted to analyze transcriptional perturbations. ChIP-seq was employed to elucidate EBF1-bound genes and the underlying regulatory mechanisms. Results: EBF1 was expressed in some human and mouse cardiomyocyte. Knockout of EBF1 inhibited cardiac development. ChIP-seq indicated EBF1's binding on promoters of cardiogenic TFs pivotal to cardiac development, facilitating their transcriptional expression and promoting cardiac development. In mouse, Ebf1 depletion triggered transcriptional perturbations of genes, resulting in cardiac remodeling. Mechanistically, we found that EBF1 directly bound to upstream chromatin regions of cardiac hypertrophy-inducing genes, contributing to cardiac hypertrophy. Conclusions: We uncover the mechanisms underlying EBF1-mediated regulatory processes, shedding light on cardiac development, and the pathogenesis of cardiac remodeling. These findings emphasize EBF1's critical role in orchestrating diverse aspects of cardiac processes and provide a promising therapeutic intervention for cardiomyopathy.

Contribution of Tregs to the promotion of constructive remodeling after decellularized extracellular matrix material implantation.

Host remodeling of decellularized extracellular matrix (dECM) material through the appropriate involvement of immune cells is essential for achieving functional organ/tissue regeneration. As many studies have focused on the role of macrophages, only few have evaluated the role of regulatory T cells (Tregs) in dECM remodeling. In this study, we used a mouse model of traumatic muscle injury to determine the role of Tregs in the constructive remodeling of vascular-derived dECM. According to the results, a certain number of Tregs could be recruited after dECM implantation. Notably, using anti-CD25 to reduce the number of Tregs recruited by the dECM was significantly detrimental to material remodeling based on a significant reduction in the number of M2 macrophages. In addition, collagen and elastic fibers, which maintain the integrity and mechanical properties of the material, rapidly degraded during the early stages of implantation. In contrast, the use of CD28-SA antibodies to increase the number of Tregs recruited by dECM promoted constructive remodeling, resulting in a decreased inflammatory response at the material edge, thinning of the surrounding fibrous connective tissue, uniform infiltration of host cells, and significantly improved tissue remodeling scores. The number of M2 macrophages increased whereas that of M1 macrophages decreased. Moreover, Treg-conditioned medium further enhanced material-induced M2 macrophage polarization in vitro. Overall, Treg is an important cell type that influences constructive remodeling of the dECM. Such findings contribute to the design of next-generation biomaterials to optimize the remodeling and regeneration of dECM materials.

Single-cell RNA-seq uncovers distinct pathways and genes in endothelial cells during atherosclerosis progression.

Background: Atherosclerosis (AS) is a chronic inflammatory disease involving various cell types, cytokines, and adhesion molecules. Herein, we aimed to uncover its key molecular mechanisms by single-cell RNA-seq (scRNA-seq) analysis. Methods: ScRNA-seq data of cells from atherosclerotic human coronary arteries were analyzed using the Seurat package. Cell types were clustered, and differentially expressed genes (DEGs) were screened. GSVA (Gene Set Variation Analysis) scores of hub pathways were compared among different cell clusters. DEGs in endothelial cells between apolipoprotein-E (ApoE)-/- mice and specific TGFbR1/2 KO ApoE-/- mice fed with high-fat diet were overlapped with those from human AS coronary arteries. In fluid shear stress and AS, hub genes were determined based on the protein-protein interaction (PPI) network, which were verified in ApoE-/- mice. Finally, hub genes were validated in three pairs of AS coronary arteries and normal tissues by histopathological examination. Results: ScRNA-seq identified nine cell clusters in human coronary arteries, namely, fibroblasts, endothelial cells, macrophages, B cells, adipocytes, HSCs, NK cells, CD8+ T cells, and monocytes. Among them, endothelial cells had the lowest fluid shear stress and AS and TGF-beta signaling pathway scores. Compared to ApoE-/- mice fed with normal diet, fluid shear stress and AS and TGF-beta scores were both significantly lower in endothelial cells from TGFbR1/2 KO ApoE-/- mice fed with normal or high-fat diet. Furthermore, the two hub pathways had a positive correlation. Three hub genes (ICAM1, KLF2, and VCAM1) were identified, and their expression was distinctly downregulated in endothelial cells from TGFbR1/2 KO ApoE-/- mice fed with normal or high-fat diet than in those from ApoE-/- mice fed with a normal diet, which were confirmed in human AS coronary artery. Conclusion: Our findings clarified the pivotal impacts of pathways (fluid shear stress and AS and TGF-beta) and genes (ICAM1, KLF2, and VCAM1) in endothelial cells on AS progression.

PRP significantly promotes the adhesion and migration of vascular smooth muscle cells on stent material.

BACKGROUND: The adhesion and survival state of cells on scaffold material is a major problem in tissue-engineered blood vessel (TEBV) culture. Platelet-rich plasma (PRP) contains a large amount of biologically active factors and fibrin, which is expected to play an important role in TEBV culture. PURPOSE: To combine PRP with cells and scaffold material to promote cell adhesion and biological activity on the scaffold material. METHODS: The adhesion status and migration of SMCs under the optimal concentration suitable for SMC growth and the optimal concentration of PRP were examined by scanning electron microscopy, HE staining, CCK-8 assays, qPCR, WB, and other experimental methods and compared with those under the conventional culture (20% FBS); finally, the effect of PRP on the deposition of ECM in vascular tissue engineering culture was verified by three-dimensional culture. RESULTS: PRP at 20% is a suitable concentration for SMCs. Compared with the control group, the 20% PRP group had better migration, and the number of SMC adhesions was significantly higher than that of the control group. In addition, collagen deposition in the experimental group was significantly higher than that in the control group. CONCLUSION: PRP (20%) can promote SMC adhesion, migration, and collagen deposition on the scaffold material.

Saturation of radiation trapping and lifetime measurements in three-level laser crystals.

In this study, we take the pump rate into consideration for the first time to give a theoretical description of radiation trapping in three-level systems. We numerically verify that under strong pumping, the population of the ground state is depleted, which leads to saturation of the radiation trapping within the pumped region. This saturation inevitably clamps the lifetime lengthening that is experimentally verified on a 0.05 at% thin ruby crystal based on the axial pinhole method. Our model is confirmed to be valid in lifetime measurement when the ruby fluorescence is collected from both the pumped and the unpumped regions.

Upregulation of the Long Non-coding RNA LINC01480 Is Associated With Immune Infiltration in Coronary Artery Disease Based on an Immune-Related lncRNA-mRNA Co-expression Network.

Coronary artery disease (CAD) is considered one of the leading causes of death worldwide. Although dysregulation of long non-coding RNAs (lncRNAs) has been reported to be associated with the initiation and progression of CAD, the knowledge regarding their specific functions as well their physiological/pathological significance in CAD is very limited. In this study, we aimed to systematically analyze immune-related lncRNAs in CAD and explore the relationship between key immune-related lncRNAs and the immune cell infiltration process. Based on differential expression analysis of mRNAs and lncRNAs, an immune-related lncRNA-mRNA weighted gene co-expression network containing 377 lncRNAs and 119 mRNAs was constructed. LINC01480 and AL359237.1 were identified as the hub immune-related lncRNAs in CAD using the random forest-recursive feature elimination and least absolute shrinkage and selection operator logistic regression. Furthermore, 93 CAD samples were divided into two subgroups according to the expression values of LINC01480 and AL359237.1 by consensus clustering analysis. By performing gene set enrichment analysis, we found that cluster 2 enriched more cardiovascular risk pathways than cluster 1. The immune cell infiltration analysis of ischemic cardiomyopathy (ICM; an advanced stage of CAD) samples revealed that the proportion of macrophage M2 was upregulated in the LINC01480 highly expressed samples, thus suggesting that LINC01480 plays a protective role in the progression of ICM. Based on the findings of this study, lncRNA LINC01480 may be used as a novel biomarker and therapeutic target for CAD.

SGLT2 inhibitor dapagliflozin reduces endothelial dysfunction and microvascular damage during cardiac ischemia/reperfusion injury through normalizing the XO-SERCA2-CaMKII-coffilin pathways.

Background: Given the importance of microvascular injury in infarct formation and expansion, development of therapeutic strategies for microvascular protection against myocardial ischemia/reperfusion injury (IRI) is of great interest. Here, we explored the molecular mechanisms underlying the protective effects of the SGLT2 inhibitor dapagliflozin (DAPA) against cardiac microvascular dysfunction mediated by IRI. Methods: DAPA effects were evaluated both in vivo, in mice subjected to IRI, and in vitro, in human coronary artery endothelial cells (HCAECs) exposed to hypoxia/reoxygenation (H/R). DAPA pretreatment attenuated luminal stenosis, endothelial swelling, and inflammation in cardiac microvessels of IRI-treated mice. Results: In H/R-challenged HCAECs, DAPA treatment improved endothelial barrier function, endothelial nitric oxide synthase (eNOS) activity, and angiogenic capacity, and inhibited H/R-induced apoptosis by preventing cofilin-dependent F-actin depolymerization and cytoskeletal degradation. Inhibition of H/R-induced xanthine oxidase (XO) activation and upregulation, sarco(endo)plasmic reticulum calcium-ATPase 2 (SERCA2) oxidation and inactivation, and cytoplasmic calcium overload was further observed in DAPA-treated HCAECs. DAPA also suppressed calcium/Calmodulin (CaM)-dependent kinase II (CaMKII) activation and cofilin phosphorylation, and preserved cytoskeleton integrity and endothelial cell viability following H/R. Importantly, the beneficial effects of DAPA on cardiac microvascular integrity and endothelial cell survival were largely prevented in IRI-treated SERCA2-knockout mice. Conclusions: These results indicate that DAPA effectively reduces cardiac microvascular damage and endothelial dysfunction during IRI through inhibition of the XO-SERCA2-CaMKII-cofilin pathway.