Circular RNA Cdyl promotes abdominal aortic aneurysm formation by inducing M1 macrophage polarization and M1-type inflammation.

Macrophage polarization plays a crucial role in regulating abdominal aortic aneurysm (AAA) formation. Circular RNAs (circRNAs) are important regulators of macrophage polarization during the development of cardiovascular diseases. How-ever, the roles of circRNAs in regulating AAA formation through modulation of macrophage polarization remain unknown. In the present study, we compared circRNA microarray data under two distinct polarizing conditions (M1 and M2 macrophages) and identified an M1-enriched circRNA, circCdyl. Loss- and gain-of-function assay results demonstrated that circCdyl overexpression accelerated angiotensin II (Ang II)- and calcium chloride (CaCl2)-induced AAA formation by promoting M1 polarization and M1-type inflammation, while circCdyl deficiency showed the opposite effects. RNA pulldown, mass spectrometry analysis, and RNA immunoprecipitation (RIP) assays were conducted to elucidate the underlying mechanisms by which circCdyl regulates AAA formation and showed that circCdyl promotes vascular inflammation and M1 polarization by inhibiting interferon regulatory factor 4 (IRF4) entry into the nucleus, significantly inducing AAA formation. In addition, circCdyl was shown to act as a let-7c sponge, promoting C/EBP-δ expression in macrophages to induce M1 polarization. Our results indicate an important role for circCdyl-mediated macrophage polarization in AAA formation and provide a potent therapeutic target for AAA treatment.

Inhibition of SENP2-mediated Akt deSUMOylation promotes cardiac regeneration via activating Akt pathway.

Post-translational modification (PTM) by small ubiquitin-like modifier (SUMO) is a key regulator of cell proliferation and can be readily reversed by a family of SUMO-specific proteases (SENPs), making SUMOylation an ideal regulatory mechanism for developing novel therapeutic strategies for promoting a cardiac regenerative response. However, the role of SUMOylation in cardiac regeneration remains unknown. In the present study, we assessed whether targeting protein kinase B (Akt) SUMOylation can promote cardiac regeneration. Quantitative PCR and Western blotting results showed that small ubiquitin-like modifier-specific protease 2 (SENP2) is up-regulated during postnatal heart development. SENP2 deficiency promoted P7 and adult cardiomyocyte (CM) dedifferentiation and proliferation both in vitro and in vivo. Mice with SENP2 deficiency exhibited improved cardiac function after MI due to CM proliferation and angiogenesis. Mechanistically, the loss of SENP2 up-regulated Akt SUMOylation levels and increased Akt kinase activity, leading to a decrease in GSK3ß levels and subsequently promoting CM proliferation and angiogenesis. In summary, inhibition of SENP2-mediated Akt deSUMOylation promotes CM differentiation and proliferation by activating the Akt pathway. Our results provide new insights into the role of SUMOylation in cardiac regeneration.

Dysregulation of miR-637 is involved in the development of retinopathy in hypertension patients and serves a regulatory role in retinol endothelial cell proliferation.

BACKGROUND: MicroRNAs (miRNAs) play an important role in the proliferation and migration of retinal endothelial cells in patients with hypertension and hypertensive retinopathy (HR). This study aimed to investigate the clinical value of miR-637 in HR and its role in retinal endothelial cell proliferation and migration. METHODS: A total of 126 subjects were recruited for the study, including 42 patients with hypertension (male/female 25/17), 42 healthy individuals (male/female 20/22), and 42 cases with HR (male/female 20/22). Except SBP and DBP, there was no significant difference in other indexes among the three groups. qRT-PCR was used to detect the expression of miR-637. The receiver operating curve (ROC) was used for diagnosis value analysis. Logistic regression analysis was used to evaluate the relationship between miR-637 and HR. CCK-8 and Transwell were used to detect the effect of miR-637 on the proliferation and migration of HUVECs. RESULTS: Compared with hypertensive patients, HR patients had the lowest expression of miR-637. The area under the curve (AUC) of miR-637 detected by the ROC curve method is 0.892, which has the ability to distinguish hypertension and HR patients. Logistic regression analysis showed that miR-637 was an independent influence factor in HR. Cell experiment results showed that overexpression of miR-637 significantly inhibited cell proliferation and migration, while downregulation of miR-637 had the opposite effect. Luciferase analysis showed that STAT3 was the target gene of miR-637. CONCLUSION: Our data indicate that miR-637 is a potential non-invasive marker for patients with HR. The action of miR-637 on STAT3 may inhibit the proliferation and migration of retinal endothelial cells, providing a possible target for the treatment of HR.

LCK inhibitor attenuates atherosclerosis in ApoE-/- mice via regulating T cell differentiation and reverse cholesterol transport.

Lots of studies demonstrated that CD4+ T cells regulate the development of atherosclerosis (AS). Previously, we reported that LCK, a key molecule in activation of T cell receptor (TCR) signalling and T cells, adversely affects reverse cholesterol transport (RCT), which ameliorates AS in vitro. To investigate the effect of LCK on AS in vivo, we injected the LCK inhibitor, PP2, into ApoE-/- mice fed a chow diet or a high-fat diet (HFD). Although, AS plaques were not affected by PP2 in chow diet-fed mice, PP2 significantly reduced the lesion percentage and necrotic core areas in HFD-fed mice. We further analysed the plaque contents and found that the accumulation of lipids and macrophages were decreased, while the contents of collagen and smooth muscle cells were increased by the LCK inhibitor. Thus, inhibiting LCK enhanced the plaque stability. We also found the LCK inhibitor improved cholesterol efflux capacity of HDL and up-regulated RCT regulatory proteins in the spleen. Moreover, inhibiting LCK regulated differentiation of T cells by increasing regulatory T (Treg) cells and decreasing the number of T helper 1 (Th1) cells in the aorta, thymus and spleen. Consistent with these results, infiltration of CD4+ T cells in plaques, secretion of pro-atherosclerotic cytokines, INF-γ and TNF-α synthesized mostly by Th1 cells, and the activation of PI3K/AKT/mTOR signalling were inhibited by the LCK inhibitor. Moreover, the effect of LCK inhibitor on the ratio of Th1 to Treg cells were compromised by activation of mTOR. Together, these data indicate that inhibiting LCK in TCR signalling attenuated the development of AS and promoted plaque stability. Improving RCT by upregulating RCT regulatory proteins and decreasing the Th1/Treg ratio by inhibiting PI3K/AKT/mTOR signalling may contribute to the anti-atherosclerotic effects of LCK inhibition.

PSRC1 overexpression attenuates atherosclerosis progression in apoE-/- mice by modulating cholesterol transportation and inflammation.

AIMS: Human genome-wide association studies (GWAS) have found that proline/serine-rich coiled-coil 1 (PSRC1) encodes a protein that is associated with serum lipid levels and coronary artery disease. In addition, our previous study showed that the cholesterol efflux capacity is decreased in macrophages following a treatment silencing Psrc1, indicating that PSRC1 has anti-atherosclerotic effects. However, the role of PSRC1 in the development of atherosclerosis is unknown. This study aims to explore the effect of PSRC1 on atherosclerosis and its underlying mechanisms. METHOD AND RESULTS: A recombinant adenovirus expressing Psrc1 (Ad-PSRC1) was constructed and transfected in RAW264.7 cells as well as injected intravenously into apoE-/- mice. The in vitro study showed that PSRC1 overexpression reduced the cellular cholesterol content, increased the cholesterol efflux capacity and inhibited foam cell formation by upregulating the expression of peroxisome proliferator-activated receptor γ (PPAR-γ) and liver X receptor α (LXR-α), which are key cholesterol transportation-related proteins. Infecting apoE-/- mice with Ad-PSRC1 inhibited the development of atherosclerotic lesions and enhanced atherosclerotic plaque stability. Consistent with these results, PSRC1 overexpression in apoE-/- mice decreased the plasma levels of TC, TG, LDL-C, TNF-α, IL-1ß and IL-6, increased the plasma HDL-C levels and improved HDL function. Similarly, the PPAR-γ and LXR-α expression levels were upregulated in the liver and in peritoneal macrophages of PSRC1-overexpressing apoE-/- mice. Finally, the liver and peritoneal macrophages of apoE-/- mice displayed elevated expression of ß-catenin, which is a direct downstream gene of PSRC1 and an upstream gene of PPAR-γ and LXR-α, but decreased activity of nuclear transcription factor (NF-κB), which acts as a key gene in the regulation of inflammation. CONCLUSIONS: PSRC1 protects against the development of atherosclerosis and enhances the stability of plaques by modulating cholesterol transportation and inflammation in macrophages and the liver of apoE-/- mice.

The prognostic value of serum α-klotho in age-related diseases among the US population: A prospective population-based cohort study.

Objective: α-Klotho is a potential biological marker of aging with satisfactory clinical applicability. However, its prognostic significance in age-related diseases has largely been undermined. Therefore, we aimed to report the prognostic value of serum α-klotho levels in age-related diseases. Methods: Participants with available serum α-klotho data from the National Health and Nutrition Examination Survey (2007-2016) were included. Their survival status was collected at 7.62 ± 2.99 years after serum α-klotho data was collected, and the endpoint was all-cause and cardiovascular mortality. A Cox regression model was established to examine the association between serum α-klotho levels and all-cause and cardiovascular mortality. Results: The present study included 13,746 U.S. adults with a survey-weighted mean age of 56.19 ± 10.42 years old. Of these, 52.2 % were female and 72.9 % were non-Hispanic whites. The optimal cutoff value of serum α-klotho for predicting all-cause mortality risk in the general population was 603.5 pg/ml. Individuals with low serum α-klotho (<603.5 pg/ml) had a significantly higher risk of all-cause (adjusted HR: 1.34(1.18-1.52), P < 0.001) and cardiovascular mortality (adjusted HR: 1.63(1.27-2.10), P < 0.001). Subgroup analysis showed that low serum α-klotho level was an independent risk factor for all-cause and cardiovascular mortality in people with hypertension, congestive heart failure, diabetes mellitus, and emphysema, while it was an independent risk factor for all-cause mortality in patients with renal insufficiency. Conclusion: A low serum α-klotho concentration (<603.5 pg/ml) could serve as a marker of all-cause and cardiovascular mortality in the general population and in people with age-related diseases, including hypertension, congestive heart failure, diabetes mellitus, and emphysema.

The combined impact of hyponatremia and hematocrit on the risk for 90-day readmission and death in patients with heart failure: dilutional hyponatremia versus depletional hyponatremia.

BACKGROUND: Hyponatremia is common in hospitalized patients with heart failure (HF) and predicts a poor prognosis after discharge. In general, hyponatremia can be divided into two types: dilutional or depletional. OBJECTIVE: Assess the impact of hyponatremia type on short-term outcomes. DESIGN: Retrospective cohort SETTINGS: Single center in China PATIENTS AND METHODS: We sorted patients by hyponatremia into two types: dilutional hyponatremia (DiH, with hematocrit <35%) and depletional hyponatremia (DeH, with hematocrit ≥35%). The Kaplan-Meier method and Cox regression analysis were used to identify the impact of hyponatremia types on the risk for 90-day readmission and death. MAIN OUTCOME MEASURES: 90-day readmission and death combined. SAMPLE SIZE: 1770 patients. RESULTS: Hyponatremia was present in 324/1770 patients with 182 cases classified as DiH versus 142 as DeH. Kaplan-Meier analyses showed a higher incidence of poor short-term outcomes in hyponatremia compared with normonatremia (log-rank P<.001), and the risk was higher in DiH than DeH although the difference was not statistically significant (log-rank P=.656). Multivariate Cox regression analyses showed that only DiH was independently associated with short-term outcomes (HR=1.34, 95%CI: 1.02-1.77, P=.038), but not DeH (HR=1.32, 95%CI: 0.97-1.80, P=.081). Analysis of the secondary endpoints showed that DiH increased the risk of readmission but not death (HR=1.36, P=.035 for readmission; HR=1.13, P=.831 for all-cause death). CONCLUSIONS: Low hematocrit, rather than high hematocrit, with hyponatremia was associated with a risk of 90-day readmission in patients with HF. LIMITATIONS: Single center, nonrandomized. CONFLICT OF INTEREST: None.

Achieving a Record Scintillation Performance by Micro-Doping a Heterovalent Magnetic Ion in Cs3 Cu2 I5 Single-Crystal.

An ultrabright, ultrafast, and low-cost ideal scintillator has been critically absent and is sorely desired in scintillation detection, but has hitherto not been found. Here, a high-quality bulk Cs3 Cu2 I5 :Mn single-crystal scintillator with ultrahigh light yield (≈95 772 photons per MeV, 137 Cs γ-rays), excellent energy resolution (3.79%, 662 keV), and ultrafast scintillation decay time (3 ns, 81.5%) is reported. In mechanism, it is found that micro-doping of a heterovalent magnetic ion (at the ppm level) can effectively modulate the luminescence kinetics of self-trapped excitons in the scintillator. Compared with previous reports, the introduction of trace amounts of magnetic Mn2+ (≈18.6 ppm) in Cs3 Cu2 I5 single-crystal shortens the scintillation decay time by several hundred times, transforming the slow decay into an ultrafast decay. Simultaneously, the light yield is also increased about three times to the highest value so far. From the comprehensive performance of the micro-doped Cs3 Cu2 I5 :Mn single-crystal, these excellent scintillation properties, physical characteristics suitable for practical applications, and low-cost advantages render this single-crystal an ideal scintillator with great potential for commercialization.

LDHA-mediated metabolic reprogramming promoted cardiomyocyte proliferation by alleviating ROS and inducing M2 macrophage polarization.

AIMS: Metabolic switching during heart development contributes to postnatal cardiomyocyte (CM) cell cycle exit and loss of regenerative capacity in the mammalian heart. Metabolic control has potential for developing effective CM proliferation strategies. We sought to determine whether lactate dehydrogenase A (LDHA) regulated CM proliferation by inducing metabolic reprogramming. METHODS AND RESULTS: LDHA expression was high in P1 hearts and significantly decreased during postnatal heart development. CM-specific LDHA knockout mice were generated using CRISPR/Cas9 technology. CM-specific LDHA knockout inhibited CM proliferation, leading to worse cardiac function and a lower survival rate in the neonatal apical resection model. In contrast, CM-specific overexpression of LDHA promoted CM proliferation and cardiac repair post-MI. The α-MHC-H2B-mCh/CAG-eGFP-anillin system was used to confirm the proliferative effect triggered by LDHA on P7 CMs and adult hearts. Metabolomics, proteomics and Co-IP experiments indicated that LDHA-mediated succinyl coenzyme A reduction inhibited succinylation-dependent ubiquitination of thioredoxin reductase 1 (Txnrd1), which alleviated ROS and thereby promoted CM proliferation. In addition, flow cytometry and western blotting showed that LDHA-driven lactate production created a beneficial cardiac regenerative microenvironment by inducing M2 macrophage polarization. CONCLUSIONS: LDHA-mediated metabolic reprogramming promoted CM proliferation by alleviating ROS and inducing M2 macrophage polarization, indicating that LDHA might be an effective target for promoting cardiac repair post-MI.

Hydrogen sulfide-loaded microbubbles combined with ultrasound mediate thrombolysis and simultaneously mitigate ischemia-reperfusion injury in a rat hindlimb model.

BACKGROUND: Thromboembolism and subsequent ischemia/reperfusion injury (IRI) remain major clinical challenges. OBJECTIVES: To investigate whether hydrogen sulfide (H2 S)-loaded microbubbles (hs-Mbs) combined with ultrasound (US) radiation (hs-Mbs+US) dissolve thrombi and simultaneously alleviate tissue IRI through local H2 S release. METHODS: hs-Mbs were manufactured and US-triggered H2 S release was recorded. White and red thromboembolisms were established ex vivo and in rats left iliac artery. All subjects randomly received control, US, Mbs+US, or hs-Mbs+US treatment for 30 minutes. RESULTS: H2 S was released from hs-Mbs+US both ex vivo and in vivo. Compared with control and US, hs-Mbs+US and Mbs+US showed comparable substantial decreases in thrombotic area, clot mass, and flow velocity increases for both ex vivo macrothrombi. In vivo, hs-Mbs+US and Mbs+US caused similarly increased recanalization rates, blood flow velocities, and hindlimb perfusion for both thrombi compared with the other treatments, with no obvious influence on hemodynamics, respiration, and macrophage vitality. More importantly, hs-Mbs+US substantially alleviated skeletal muscle IRI by reducing reactive oxygen species, cellular apoptosis, and proapoptotic Bax, caspase-3, and caspase-9 and increasing antiapoptotic Bcl-2 compared with other treatments. In vitro, hypoxia/reoxygenation-predisposed skeletal muscle cells and endothelial cells treated with normal saline solution exhibited similar trends, which were largely reversed by an H2 S scavenger or an inhibitor of Akt phosphorylation. CONCLUSION: hs-Mbs+US effectively dissolved both white and red macrothrombi and simultaneously alleviated skeletal muscle IRI through the US-triggered, organ-specific release of H2 S. This integrated therapeutic strategy holds promise for treating thromboembolic diseases and subsequent IRI.

[Correlation of lipoprotein(a) with clinical stability and severity of coronary artery lesions in patients with coronary artery disease].

OBJECTIVE: To analyze the correlation of lipoprotein(a) [Lp(a)] with the clinical stability and severity of coronary artery stenosis in patients with coronary artery disease (CAD). METHODS: A total of 531 patients undergoing coronary angiography in Nanfang Hospital between January, 2013 and December, 2016 were enrolled in this study. At the cutoff Lp(a) concentration of 300 mg/L, the patients were divided into high Lp(a) group (n=191) and low Lp(a) group (n=340). In each group, the patients with an established diagnosis of CAD based on coronary angiography findings were further divided into stable angina pectoris (SAP) group and acute coronary syndrome (ACS) group. The correlation between the severity of coronary artery stenosis and Lp(a) was evaluated. RESULTS: The patients in high and low Lp(a) groups showed no significant differences in age, gender, body mass index, smoking status, hypertension, or diabetes (P>0.05). Multivariate logistic regression analysis revealed that age, gender, and serum levels of low-density lipoprotein cholesterol (LDL-C) and Lp(a) were independent risk factors for CAD in these patients. A high Lp(a) level was associated with an increased risk of CAD (OR=2.443, 95%CI: 1.205-4.951, P=0.013). The patients with a high Lp(a) level were at a significantly higher risk of CAD than those with a low Lp(a) level irrespective of a low or high level of LDL-C (P=0.006 and 0.020). In the patients with CAD, the ACS group had a significantly higher Lp(a) level than the SAP group (P < 0.001); the proportion of the patients with high Gensini scores was significantly greater in high Lp(a) group than in low Lp(a) group (17.3% vs 5.6%, P=0.026), and a linear relationship was found between Lp(a) level and Gensini score (R=0.130, P=0.006). CONCLUSIONS: Serum level of Lp(a) is an independent risk factor for CAD, and an increased Lp(a) is the residual risk for CAD. In patients with CAD, a high Lp(a) level is associated with the clinical instability and severity of coronary artery stenosis.

ZAP70 deficiency promotes reverse cholesterol transport through MAPK/ERK pathway in Jurkat cell.

BACKGROUND: Lots of studies have demonstrated that immune cells could regulate reverse cholesterol transport (RCT). However, neither T cell receptor (TCR) signalling nor Zeta-chain associated protein 70 (ZAP70) have been demonstrated to be associated with RCT. To investigate this association, we used a ZAP70-deficient Jurkat-derived mutant, P116 cell line, to detect the effect of ZAP70 on RCT and inflammatory response. ZAP70 deficiency improved cholesterol efflux capacity by 14%. Meanwhile, mRNA and proteins expression of RCT regulatory proteins such as ABCA1, ABCG1 and SR-BI were increased in P116 cells. ZAP70-deficiency had no influence on LXR-α and PPAR-γ. Regarding the inflammatory response, the mRNA expression and secretion of pro-atherosclerotic cytokines, TNF-α, IFN-γ, IL-2 and IL-6, were significantly decreased in the ZAP70-deficient cell line. Activation of MAP kinases cascades, as determined by of ERK, JNK and p38 MAPK phosphorylation, were found to be inhibited in the absence of ZAP70. Specific inhibition of ERK, JNK and p38 MAPK activity was also found to decreased TNF-α, IFN-γ, and IL-6 secretion. However, only the ERK inhibition was observed to reduce IL-2 secretion, improve cholesterol efflux capacity and increase expression of ABCA1, ABCG1 and SR-BI without increasing LXR-α and PPAR-γ. Using ChIP assay to detect the binding of LXR-α to LXRE, which promotes the expression of ABCG1, we found that inhibiting ERK improved binding without increasing LXR-α levels. Thus, we speculate that ZAP70-deficiency may improve RCT and decrease the inflammatory response of T cells. Furthermore, these effects are probably achieved via ERK signalling pathway.