Erythrocytes from patients with ST-elevation myocardial infarction induce cardioprotection via the purinergic P2Y13 receptor and nitric oxide signalling

Background

Red blood cells (RBC) are suggested to act as important mediators in the regulation of cardiovascular function by exporting nitric oxide (NO) bioactivity and ATP under hypoxic/ischemic conditions. In addition, RBCs are known to protect from ischemia-reperfusion injury via the export of NO bioactivity in experimental settings. However, it remains unknown if such beneficial effects of RBCs are protective in patients with acute myocardial infarction.

Purpose

To investigate whether RBCs from patients with ST-elevation myocardial infarction (STEMI) protect against myocardial ischemia-reperfusion injury and whether such effect involves activation of purinergic and NO signalling in the RBCs.

Methods

RBCs were collected from patients with STEMI undergoing primary percutaneous coronary intervention and age- and gender-matched healthy controls. The RBCs were administered into the coronary circulation of isolated Langendorff-perfused rat hearts at the onset of global ischemia for 25 min followed by reperfusion of 60 min. Recovery of left ventricular developed pressure (LVDP) during reperfusion and infarct size were determined. All animal experiments and procedures were performed according to the guidelines by the U.S National Institutes of Health (NIH publication no 85–23, revised 1996). The present study was performed following The Code of Ethics of the World Medical Association outlined in the Declaration of Helsinki of 1975 and revised in 1983 for experiments that involve human subjects.

Results

Administration of RBCs from STEMI patients improved recovery of LVDP and reduced infarct size in hearts subjected to ischemia-reperfusion in comparison with RBCs from healthy controls (Figure 1A, B). Pre-incubation of the RBCs with the NO synthase (NOS) inhibitor L-NAME (Figure 1C, D) and the inhibitor of the NO receptor soluble guanylyl cyclase (sGC) ODQ abolished the cardioprotective effect of RBCs from STEMI patients. The cardioprotective effect was also attenuated by inhibition of cardiac cGMP-dependent protein kinase (PKG). Further, the purinergic P2Y13 receptor antagonist MRS2211 (Figure 1E, F), but not the P1 receptor antagonist 8PT applied to RBCs, attenuated the cardioprotection induced by RBCs from STEMI patients. Moreover, administration of RBCs from healthy subjects pre-incubated with a cell permeable ATP analogue improved post-ischemic recovery of LVDP and reduced infarct size. This cardioprotective effect was abolished by co-incubation of the RBCs with ODQ (Figure 2) and MRS2211.

Conclusion

Our findings demonstrate a novel function of RBCs in patients with STEMI that provides protection against myocardial ischemia-reperfusion injury via the activation of P2Y13 receptor and the NO-sGC pathway in RBCs and cardiac PKG.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Swedish Heart and Lung Foundation; Swedish Research Council

Systolic blood pressure time in range and long-term clinical outcomes in patients with ischaemic cardiomyopathy

Background

The relationship between systolic blood pressure (SBP) control and long-term clinical outcomes in patients with ischaemic cardiomyopathy remains unclear. It has been previously reported that either too high or too low SBP may lead to a poorer prognosis. But current SBP control metrics may not take into account the possible effects of fluctuating SBP overtime on patients.

Purpose

This study aimed to estimate the association between time in range (TIR) of SBP and long-term clinical outcomes in patients with ischaemic cardiomyopathy.

Methods

This study was a post-hoc analysis of The Surgical Treatment of Ischaemic Heart Failure (STICH) trial, a randomized controlled trial with two hypotheses that enrolled participants with coronary artery disease and left ventricular ejection fraction ≤35%. The SBP target range of the TIR was defined as 110 to 130 mmHg and the SBP TIR was calculated by linear interpolation method. Patients were equally divided into four groups by quartiles of TIR. Multivariable-adjusted Cox proportional hazards regression models were constructed to compare the effects of different levels of TIR on a 10-year prognosis. The primary outcome was all-cause mortality. Subgroup analyses were performed according to whether patients were assigned to coronary artery bypass grafting (CABG) or medical therapy (MED), and in populations with different baseline SBP.

Results

A total of 1194 eligible patients were included according to the purpose of our study. Compared with patients in the quartile 4 group (TIR 77.87–100%), the fully adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) of all-cause mortality were 1.32 (0.98–1.78) for quartile 3 group (TIR 54.81–77.63%), 1.40 (1.03–1.90) for quartile 2 group (TIR 32.59–54.67%), and 1.53 (1.14–2.04) for quartile 1 group (TIR 0–32.56%) (P for trend = 0.005). When evaluated TIR as a continuous variable, per 1-SD decrement (29.28%) in TIR significantly increased the incidence of all-cause mortality [1.15 (1.04–1.26)]. Similarly, the decrement in TIR significantly elevated the risk of cardiovascular (CV) mortality and the risk of all-cause mortality plus CV rehospitalization. Consistent results were also observed in subgroup analyses of either CABG or MED, or different baseline SBP, indicating the robustness of our findings.

Conclusions

This study suggested that in patients with ischaemic cardiomyopathy, a higher SBP TIR was significantly associated with a decreased risk of all-cause mortality, CV mortality and the composite of all-cause mortality plus CV rehospitalization, regardless of whether the patient received CABG or MED, and the level of baseline SBP. Our findings support that TIR might be a substitutable metric of SBP control for long-term clinical outcomes in patients with ischaemic cardiomyopathy.

Funding Acknowledgement

Type of funding sources: None.

Red blood cells induce endothelial dysfunction in patients with ST-elevation myocardial infarction and elevated C-reactive protein

Background

The important role of inflammation in atherosclerotic plaque progression and instability leading to myocardial infarction has been widely demonstrated. C-reactive protein (CRP) has been shown to be of predictive value in atherosclerotic cardiovascular disease. The red blood cell (RBC) is an important regulator of cardiovascular function through nitric oxide bioactivity and oxidative stress in ischemic heart disease. Also, arginase-1 has been shown to greatly influence nitric oxide bioactivity in RBCs and to cause endothelial dysfunction. However, the mechanisms by which RBCs regulate vascular function in patients with myocardial infarction and its relation to inflammation and arginase-1 remain unknown.

Objective

The study aimed to investigate the effect of RBCs on endothelial function in patients with ST-elevation myocardial infarction (STEMI) and its possible association with systemic inflammation and arginase-1.

Material and methods

Blood samples were collected from patients with STEMI within 36 h after admission and from age-matched healthy controls. RBCs were incubated with isolated rat aortic segments for 18 h after which the aortas were assessed for endothelium-dependent and endothelium-independent relaxations using wire myographs and application of acetylcholine and nitroprusside, respectively. The vascular response was evaluated in relation to the level of inflammation defined as CRP <2 and ≥2 mg/L at admission. The levels of 4-hydroxynonenal (4-HNE; a marker of oxidative stress formed by lipid peroxidation) and the expression of arginase-1 were visualized in rat aortas following incubation with RBCs by immunohistochemistry. All handling and procedures regarding human subjects and sampling were performed according to the Declaration of Helsinki. All animal experiments and procedures were performed according to the guidelines by the U.S National Institutes of Health (NIH publication no 85–23, revised 1996).

Results

RBCs from patients with STEMI and elevated CRP (≥2 mg/L, mean of 9.6 mg/L) induced significant impairment of endothelium-dependent relaxation compared to RBCs from patients with STEMI and low CRP (<2 mg/L, mean of 1.0 mg/L) and to the healthy controls (Fig. 1). Endothelium-independent relaxations did not differ between the groups. Immunohistochemical staining of the aorta revealed that incubation with RBCs from patients with STEMI and high CRP increased the expression of 4-HNE and arginase-1 compared to incubation of RBCs from healthy controls and patients with STEMI and low CRP (Fig. 2).

Conclusion

RBCs from patients with STEMI and elevated CRP induce endothelial dysfunction and increase the expression of 4-HNE and arginase-1, indicating that inflammation is involved in the mechanism by which RBCs induce endothelial dysfunction in STEMI.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Swedish Heart and Lung foundation

Maximally tolerated guideline-directed medical therapy and barriers to optimization in patients with heart failure with reduced ejection fraction: the COAPT trial

Background

The COAPT trial of MitraClip therapy employed a central screening eligibility committee (CSEC) of heart failure (HF) experts to ensure the use of maximally tolerated guideline-directed medical therapy (GDMT) and systematically document intolerances in all potential patients prior to approval for randomization.

Purpose

To describe the percentage of GDMT classes, doses tolerated, predictors of intolerance, and specific intolerances limiting GDMT among patients approved for randomization by the CSEC.

Methods

We analyzed baseline use, dose, and intolerances of i) angiotensin-converting enzyme inhibitors (ACEI), angiotensin II receptor blockers (ARB) or angiotensin receptor neprilysin inhibitor (ARNI); ii) beta-blockers (BB); and iii) mineralocorticoid receptor antagonists (MRA) in the CSEC-approved COAPT population with HF with reduced ejection fraction (HFrEF; LVEF ≤40%). We analyzed variables associated with GDMT tolerance.

Results

In COAPT, 464 patients had HFrEF and complete screening medication information. Any dose of all 3, 2 or 1 GDMT classes were tolerated in 39%, 39% and 20% of patients respectively; only 2% of patients (n=9) could not tolerate any GDMT (Figure 1). BB were prescribed in the most (93%) patients followed by ACEI/ARB/ARNI (69%) and MRA (55%). Intolerances limiting each GDMT class differed, but hypotension and kidney dysfunction were most common (Figure 2). No patients tolerated goal doses of all 3 GDMT classes. For BB, only 32% tolerated ≥50% of the goal dose; while for ACEI/ARB/ARNI, no patients achieved goal doses, and only 1% tolerated ≥50% of the goal dose. For MRA, 86% of patients tolerated 25mg/day or less. Patients intolerant of BB were less likely to tolerate an ACEI/ARB/ARNI (OR 0.39, 95% CI 0.20–0.76; p=0.004) but not a MRA (p=0.21) compared with patients tolerating a low dose BB. Patients intolerant of MRA were less likely to tolerate ACEI/ARB/ARNI therapy (OR 0.37, 95% CI 0.25–0.57; p<0.0001) but not a BB (p=0.31) compared with patients tolerating MRA. Patients tolerating low dose ACEI/ARB/ARNI had a higher baseline mean eGFR (52±21 versus 40±21 ml/min/m2; p<0.0001) compared with patients intolerant of ACEI/ARB/ARNI. Likewise, patients tolerating MRA had a higher baseline mean eGFR (52±21 versus 42±21 ml/min/m2; p<0.0001) compared with patients intolerant of MRA.

Conclusion

In a contemporary trial in which HF specialists ensured GDMT optimization, many patients had medical intolerances prohibiting use of one or more GDMT classes, and few patients tolerated target doses. These findings indicate medical intolerances are the primary cause of low GDMT prescription rates in patients with moderate to severe HFrEF. Yet, use of GDMT in this very ill population was much better than “real world” registries of HFrEF suggesting that mandating careful CSEC review prior to study enrollment is important for clinical trials having the objective of randomizing a maximally treated patient cohort.

Funding Acknowledgement

Type of funding sources: None.

Overexpression of miR-210 ameliorates endothelial dysfunction in type 2 diabetic mice

Background

MicroRNA (miR)-210 plays a protective role in many cardiometabolic diseases, and its levels are reduced in whole blood, erythrocytes, and plasma in type 2 diabetes mellitus (T2DM). Our recent study demonstrated that miR-210 is downregulated in carotid artery plaques from patients with T2DM compared to non-diabetic patients. However, the functional role of miR-210 in endothelial dysfunction is not fully understood.

Purpose

This study aimed to investigate the potential therapeutic value of miR-210 overexpression against T2DM-associated endothelial dysfunction.

Methods

miR-210 transgenic mice (TG) at age of 8 weeks were subjected to Western Diet (WD) for 12 weeks. During the last 10 days of the diet regime, doxycycline or vehicle dissolved in drinking water was given to switch on miR-210 (miR-210/on) expression or keep it off (miR-210/off), respectively. Age-matched wild-type (WT) control mice received normal chow through the same period. Additionally, WT and T2DM db/db mice at age of 15–20 weeks received tail vein injections of miR-210 mimic or miR-210 scramble oligonucleotides. All animals were euthanized at the end of the treatment or 72h after the i.v. injections for determination of endothelial function by acetylcholine-induced endothelium-dependent relaxation (EDR) of isolated aortic segments from all groups of mice using wire myographs. The expression of protein tyrosine phosphatase 1B (PTP1B; a miR-210 target protein) and the levels of 4-hydroxynonenal (4-HNE; an oxidative stress marker) were measured in aortic segments by immunohistochemistry. All animal experiments and procedures were performed according to the guidelines by the U.S National Institutes of Health (NIH publication no 85–23, revised 1996).

Results

EDR in aortic segments from miR-210/off TG mice fed WD and T2DM db/db mice injected with miR-210 scramble was significantly impaired compared to vessels from WT controls fed with regular chow (Fig. 1A, B). Of note, EDR was markedly improved or even restored in aortae from miR-210/on TG mice treated with WD and T2DM db/db mice injected with miR-210 mimic (Fig. 1A, B). Furthermore, the expression of PTP1B and the levels of 4-HNE, which is formed by lipid peroxidation, were significantly elevated in the aortae from miR-210/off TG mice treated with WD when compared to WT controls (Fig. 2A–D). The expression was attenuated in aortae of miR-210/on TG mice treated with WD compared to miR-210/off TG mice (Fig. 2A–D). There was a significant increase in the expression of PTP1B and a trend to increased 4-HNE levels in aortae of db/db mice injected with miR-210 scramble vs. control mice (Fig. 2E–H). A significant reduction in PTP1B but not 4-HNE was observed in db/db mice injected with miR-210 mimic (Fig. 2E–H).

Conclusion

Genetic and pharmacological overexpression of miR-210 ameliorates endothelial dysfunction in mice fed with WD and db/db mice. Increasing miR-210 levels may become a potential treatment strategy.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Swedish Heart and Lung Foundation

Evolution and clinical implications of right ventricular dysfunction in ischemic cardiomyopathy with or without coronary artery bypass surgery

Background

The Surgical Treatment of Ischemic Heart Failure (STICH) trial demonstrated that coronary artery bypass grafting (CABG) provides additional survival benefits to patients with ischemic cardiomyopathy. However, it remains unclear whether this benefit is affected by preoperative right ventricular (RV) function and how post-therapeutic evolution of RV function influences long-term outcomes.

Purpose

We sought to investigate the implications of baseline RV function on therapeutic decision-making in patients with ischemic cardiomyopathy, and to evaluate the prognostic implications of post-therapeutic evolution of RV function.

Methods

Patients with available baseline echocardiographic RV function assessed by experienced Echocardiography Core Laboratory physicians were included from the hypothesis 1 of the STICH trial. The primary outcome was long-term all-cause mortality.

Results

A total of 1042 patients were included, among them 757 (72.7%) had normal RV function, 143 (13.7%) mild right ventricular dysfunction (RVD), and 142 (13.6%) moderate to severe RVD. After a median follow-up of 9.8 years, patients with RVD had a higher risk of all-cause mortality compared with patients with normal RV function [mild RVD: adjusted hazard ratio (aHR) 1.32; 95% confidence interval (CI) 1.06–1.64; moderate to severe RVD: aHR, 1.74; 95% CI 1.39–2.18]. Although no significant interaction was detected between RVD degree and treatment allocation (P for interaction = 0.399), a gradually decreasing survival benefit associated with CABG was observed among patients with normal RV function (aHR: 0.79; 95% CI: 0.65–0.96), mild RVD (aHR: 0.85; 95% CI: 0.56–1.29), and moderate to severe RVD (aHR: 0.97; 95% CI: 0.67–1.43). Among 746 patients with available RV function assessed at baseline and post-therapeutic 4-month follow-up, there was a gradient of increasing risk for all-cause mortality across patients with consistent normal RV function, recovery of RVD (aHR: 1.20; 95% CI: 0.88–1.64), newly developed RVD (aHR: 1.59; 95% CI: 1.18–2.14), and consistent RVD (aHR: 2.06; 95% CI: 1.60–2.67). Independent predictors of RVD recovery included baseline left ventricular ejection fraction (per 1-percent increment, adjusted odds ratio: 1.04; 95% CI: 1.00–1.09) and mitral regurgitation ≥ grade 2 (adjusted odds ratio: 0.42; 95% CI: 0.21–0.84).

Conclusions

Baseline RVD was associated with an increased risk of long-term mortality in patients with ischemic cardiomyopathy, and adding CABG to medical therapy might provide limited survival benefits in patients with moderate to severe RVD. A gradient of increasing risk for mortality was observed across different categories of RV function evolution, which emphasizes the necessity of pre- and post-therapeutic RV assessment for prognostic evaluation.

Funding Acknowledgement

Type of funding sources: None.

[Association of nutritional status with clinical outcomes of stroke patients with acute anterior circulation large vessel occlusion after emergency endovascular treatment]

OBJECTIVE

To explore the influence of nutritional status on 90-day functional outcomes of stroke patients with acute large vessel occlusion in the anterior circulation after endovascular treatment (EVT).

METHODS

We retrospectively analyzed the baseline, laboratory, surgical and 90-day follow-up data of patients with stroke resulting from acute large vessel occlusion in the anterior circulation, who underwent emergency endovascular treatment in our hospital from July, 2015 to December, 2020. A favorable outcome was defined as a modified Rankin scale score ≤2 at 90 days. Univariate and multivariate regression analyses were performed to explore the relationship between nutritional status and 90-day functional outcomes of the patients.

RESULTS

A total of 459 patients (mean age of 68.29±11.21 years, including 260 males) were enrolled in this study. According to their prognostic nutritional index (PNI), the patients were divided into normal nutrition group (392 cases, 85.4%), moderate malnutrition group (44 cases, 9.6%), and severe malnutrition group (23 cases, 5.0%). Univariate analysis showed that the patients with good clinical outcomes had a lower proportion of malnutrition with a younger age, a lower rate of diabetes, lower baseline blood pressure, lower baseline NIHSS score, higher baseline ASPECT score, and higher rates of good collateral circulation and complete vascular recanalization. Multivariate analysis showed that in addition to age, diabetes, baseline systolic blood pressure, successful recanalization, baseline ASPECT score, baseline NIHSS score and collateral circulation, a greater PNI was a protective factor for a good 90-day outcome of patients after EVT (moderate vs severe: OR=0.245, 95% CI: 0.066-0.908, P=0.035; normal vs severe: OR=0.185, 95% CI: 0.059-0.581, P=0.004).

CONCLUSION

Nutritional status an important factor affecting the 90-day outcomes after EVT of stroke patients with acute large vessel occlusion in the anterior circulation.

[Determination of chlorobenzene metabolite-p-chlorophenol in urine by solid phase extraction-gas chromatography]

Objective: A method to determine chlorobenzene metabolite-p-chlorophenol in urine by solid phase extraction-gas chromatography was established. Methods: In May 2021, the urine sample was hydrolyzed at 100 ℃ for 1.5 h with 2 ml concentrated hydrochloric acid. After cooling and filtering, the sample was enriched and purified by Oasis(®)MAX 6cc SPE column. Drip washing with 0.01 mol/L hydrochloric acid solution and elution with acetonitrile, the eluent was volumized to 5 ml with acetonitrile and determined by gas chromatography, and quantify by standard curve method. Results: Calibration curve of the method was linear within the range of 1.61-80.30 μg/ml and showed good linearity with r=0.9997, the regression equation was y=1.51602x-0.10234. The determination limit was 0.17 μg/ml, and the limit of quantitation was 0.55 μg/ml. Recovery rates were between 89.3%-104.4%, the relative standard deviation (RSD) of intra-day measurements ranged from 4.3% to 6.7%, and the RSD of inter-day measurements ranged from 4.5% to 6.7%. Conclusion: This method could optimize sample pretreatment, and eliminate the interference of impurities, which is sensitive, efficient and accurate for the determination of chlorobenzene metabolite-p-chlorophenol in urine.

[Cardiovascular biomarkers improve precise risk assessment for cardiovascular diseases]

Cardiovascular diseases (CVD) is an urgent threat to Chinese. It is of primary importance to assess risk for cardiovascular diseases. However, there are some limitations about traditional tools for CVD risk assessment. Recently, numbers of clinical trials demonstrated that CVD risk assessments based on cardiovascular biomarkers would significantly improve sensitivity and specificity of prediction. The comment review the limitations of traditional tools for CVD risk assessment, the application value of novel tools and advances of cardiovascular biomarkers in CVD prediction. It is benefit for precise stratification and management of general population during risk stage. Archieving the strategic goal of"Healthy China"would be promising soon.

Search for Subsolar-Mass Binaries in the First Half of Advanced LIGO's and Advanced Virgo's Third Observing Run

We report on a search for compact binary coalescences where at least one binary component has a mass between 0.2  M_{⊙} and 1.0  M_{⊙} in Advanced LIGO and Advanced Virgo data collected between 1 April 2019 1500 UTC and 1 October 2019 1500 UTC. We extend our previous analyses in two main ways: we include data from the Virgo detector and we allow for more unequal mass systems, with mass ratio q≥0.1. We do not report any gravitational-wave candidates. The most significant trigger has a false alarm rate of 0.14  yr^{-1}. This implies an upper limit on the merger rate of subsolar binaries in the range [220-24200]  Gpc^{-3} yr^{-1}, depending on the chirp mass of the binary. We use this upper limit to derive astrophysical constraints on two phenomenological models that could produce subsolar-mass compact objects. One is an isotropic distribution of equal-mass primordial black holes. Using this model, we find that the fraction of dark matter in primordial black holes in the mass range 0.2  M_{⊙}<m_{PBH}<1.0  M_{⊙} is f_{PBH}≡Ω_{PBH}/Ω_{DM}≲6%. This improves existing constraints on primordial black hole abundance by a factor of ∼3. The other is a dissipative dark matter model, in which fermionic dark matter can collapse and form black holes. The upper limit on the fraction of dark matter black holes depends on the minimum mass of the black holes that can be formed: the most constraining result is obtained at M_{min}=1  M_{⊙}, where f_{DBH}≡Ω_{DBH}/Ω_{DM}≲0.003%. These are the first constraints placed on dissipative dark models by subsolar-mass analyses.

Physical activity patterns, genetic susceptibility, and risk of hip/knee osteoarthritis: a prospective cohort study based on the UK Biobank

OBJECTIVES

The effect of physical activity on hip/knee osteoarthritis (OA) and how it varies by genetic susceptibility to OA remains inconclusive.

METHODS

In a cohort study of UK Biobank, 436,166 OA-free participants were recruited in 2006-2010 and followed for knee/hip OA until the end of 2020. 28 physical activity-related items were collected at baseline. Cox regression was used to estimate associations between physical activity behaviors, as well as major activity patterns (i.e., significant principal components[PCs] identified by principal component analysis), and risk of OA, adjusting for multiple confounders. We further stratified the analyses by polygenic risk score (PRS) for OA to examine the impact of genetic susceptibility to OA on the studied association.

RESULTS

During a mean follow-up of 11.15 years, 13,227 hip and 21,119 knee OA cases were identified. 19, out of 28, studied items showed associations with increased OA risk. Compared with low adherence group(<1^st tertile of PC score for each pattern), individuals with high adherence to five identified patterns were associated with increased risk of OA. The moderate adherence to "strenuous sports"(HR = 0.93, 95%CI: 0.89-0.97) and "walking for pleasure"(HR = 0.93, 95%CI: 0.89-0.98) patterns was associated with reduced OA. Similar risk patterns were obtained in the stratified analysis by PRS levels for OA.

CONCLUSION

High intensity of most activity patterns were associated with increased OA. However, a protective effect was suggested for moderate adherence to patterns of "strenuous sports" and "walking for pleasure" that consistent across different genetic susceptibilities, underscoring the potential benefits of moderate-intensity physical activity on OA.

[Preliminary evaluation on the efficacy of emergency transcatheter aortic valve replacement: a multicenter study]

Objectives: To explore the efficacy and safety of emergency transcatheter aortic valve replacement (TAVR). Methods: Data of patients who underwent emergency TAVR in eight centers, namely Fuwai Hospital, Wuhan Asia Heart Hospital, Xijing Hospital, Union Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology, Guangdong Provincial People's Hospital, Zhongshan Hospital Affiliated to Fudan University, the First Affiliated Hospital of Zhengzhou University, the Second Xiangya Hospital of Central South University, between May 2017 and December 2020 were retrospectively analyzed. The use of mechanical circulatory support system (MCS) and the results of laboratory tests (N-terminal B-type natriuretic peptide (NT-proBNP)) and echocardiography (mean aortic valve cross valve pressure difference and left ventricular ejection fraction) before and after operation were collected. The primary endpoint was all-cause death, and the secondary endpoints were stroke, major bleeding, major vascular complications, myocardial infarction, permanent pacemaker implantation, and acute renal injury. Device success was caculated, which refered to absence of procedural mortality and correct positioning of a single prosthetic heart valve into the proper anatomical location and intended performance of the prosthetic heart valve (mean aortic valve gradient<20 mmHg(1 mmHg=0.133 kPa) or peak velocity<3 m/s, with no moderate or severe prosthetic valve regurgitation). Kaplan-Meier survival curve was used to estimate the survival rate of patients during follow-up. Results: This study included 48 patients. The age was (72.5±8.1) years, and 34 patients were males (70.8%). Device success rate was 91.7% (44/48). The mean aortic valve transvalvular pressure was significantly decreased after operation ((12.3±6.4)mmHg vs. (60.2±23.8)mmHg, P<0.000 1). Left ventricular ejection fraction was significantly increased ((41.5±11.7)% vs. (31.0±11.3)%, P<0.000 1). NT-proBNP significantly decreased (3 492.0 (1 638.8, 7 165.5) ng/L vs. 12 418.5 (6 693.8, 35 000.0) ng/L, P<0.000 1). In-hospital all-cause mortality was 8.3% (4/48). During hospitalization, the rate of stroke was 2.1% (1/48), major bleeding was 6.3% (3/48), major vascular complications was 10.4% (5/48), myocardial infarction was 4.2% (2/48), permanent pacemaker implantation was 6.3% (3/48), and the rate of acute renal injury was 12.5% (6/48). MCS was used in 20 patients (41.7%). The median follow-up time was 196 days. During the follow-up, one patient died (due to systemic metastasis of pancreatic cancer), two cases suffered new myocardial infarction and one case received permanent pacemaker implantation. The survival rate of 30 days, 1 year and 2 years after the operation were 91.7% (44/48), 89.6% (43/48), 89.6% (43/48), respectively. Conclusion: Emergency TAVR may be a safe and effective treatment for patients with severe decompensated aortic valve stenosis.

[Single center experience of transcatheter aortic valve replacement with a simplified operative protocol]

Objective: To summarize the single center experience of transcatheter aortic valve replacement (TAVR) with a simplified operative protocol. Methods: Consecutive patients who underwent transfemoral TAVR (TF-TAVR) from July 2020 to December 2020 in Fuwai Hospital were retrospectively analyzed. We compared the baseline characteristic, procedure information, 30-day follow-up outcomes of the patients who underwent TF-TAVR without the simplified operative protocol (routine group) or with the simplified operative protocol (simplified protocol group). Results: 93 patients were collected, 42 patients belonging to routine group, 51 patients belonging to simplified protocol group. In simplified protocol group, there were 51 patients planned to use ultrasound-guided femoral access puncture, procedure was successful in all 51 patients (100%). There were 49 patients planned to use the radial artery as the secondary access, procedure was successful in 45 patients (92%). There were 48 patients planned to use the strategy of avoidance of urinary catheter, this strategy was achieved in 35 patients (73%). There were 12 patients planned to use the left ventricular guidewire to pace, procedure was successful in 11 patients (92%). There were no differences in baseline characteristics, major clinical endpoints and 30-day follow-up outcomes between the two groups. Meanwhile, the procedure time ((62.5±17.9)min vs. (78.3±16.7)min, P<0.001), operation room time ((133.7±25.1)min vs. (159.2±42.6)min, P<0.001), X-ray exposure time ((17.2±6.5)min vs. (20.2±7.7)min, P=0.027) were significantly shorten in simplified protocol group compared with the routine group. Conclusion: Our study results indicate that the simplified operative protocol of TF-TAVR is as effective and safe as the routine operative protocol, meanwhile using the simplified operative protocol can significantly increase the operative efficiency of TF-TAVR.

[Comparison of efficacy and safety between new oral anticoagulants and traditional anticoagulants in patients with liver cirrhosis requiring anticoagulant therapy]

Objective: To compare the advantages and disadvantages of new oral anticoagulants (NOACs) with traditional anticoagulants, in an attempt to evaluate their efficacy and safety in patients with liver cirrhosis requiring anticoagulant therapy. Methods: Relevant literatures were searched from PubMed, Embase, Cochrane Library, HowNet, Wanfang, VIP and other databases by computer retrieval. The literatures quality was evaluated by NOS. The extracted data were meta-analyzed by RevMan5.3 software. Results: A total of seven studies were included, including one randomized controlled trial and six retrospective cohort studies with a total of 3042 cases. Among them, 1677 and 1365 cases used NOACs and traditional anticoagulants. Meta-analysis results showed that compared with the traditional anticoagulant group, the NOACs group had a lower incidence of massive hemorrhage [OR=0.56, 95%CI (0.37-0.85), P＜0.01] and a higher thrombotic recanalization rate [OR=7.77, 95%CI (3.48~17.34), P＜0.01], and the difference was statistically significant, while there were no statistically significant differences between the two groups in comparison to all-cause bleeding rates [OR=0.72, 95%CI (0.13-3.91), P=0.07], all-cause mortality [OR=0.72, 95%CI (0.25-2.07), P=0.54], recurrent embolism and stroke rates [OR=0.90, 95%CI (0.59-1.39), and P=0.64]. Conclusion: Compared with traditional anticoagulants, NOACs have higher safety and better efficacy in the treatment of patients with liver cirrhosis, but it has not been widely used in China. Therefore, large-scale randomized controlled trials and prospective studies are further needed to confirm it in the future.

Assembly of Ultralong Hydroxyapatite Nanowires into Enamel-like Materials

To develop dental restorative materials with enamel-like structures, ultralong hydroxyapatite (HA) nanowires were synthesized by a hydrothermal method, followed by functionalization with 3-methacryloxypropyltrimethoxysilane (KH-570). The mixture of HA nanowires, KH-570, and light initiator was stirred and centrifuged. The precipitate was vacuum filtered to remove excessive KH-570 and then pressured under cold isostatic pressing (10 MPa × 24 h). Finally, the block was polymerized by lighting. Scanning electron microscopy and transmission electron microscopy showed that HA nanowires with aspect ratios >1,000 were assembled into enamel rod-like microstructures and evenly dispersed in the polymerized KH-570 silane matrix to form enamel-like structures. Thermogravimetric analysis demonstrated that the content of HA nanowires reached 72 wt% in the composite. The enamel-like composite showed a similar hardness, frictional property, and acid-etching property to those of enamel and a comparable or even better diametral tensile strength and compressive strength than some commercial composite resins in mechanical tests in vitro. In addition, the enamel-like composite had good cytocompatibility. Such enamel-like composites may have the potential to be used in biomimetic tooth restorations in the future.

POS0102 GLOBAL CHARACTERIZATION OF SALIVARY GLANDS IMMUNE MICROENVIRONMENT IN PRIMARY SJÖGREN’S SYNDROME BY SINGLE-CELL SEQUENCING

Background

Primary Sjögren’s syndrome (pSS) is a heterogeneous, chronic, complex systemic autoimmune disease. The hallmark symptom of the disease is exocrinopathy, chiefly salivary and lachrymal glands, which often results in dryness of the mouth and eyes. As of today, although a lot of genetic and epigenetic studies have reveal the complexity of pSS to a certain extent, but the knowledge of existing pSS disease heterogeneity is still limited and the immune mechanisms of salivary glands (SG) injury have been challenging to clarify.

Objectives

Single-cell RNA sequencing (scRNA-seq) is a powerful tool capable of defining cell types and states on the basis of their individual transcriptome in a given sample from health and disease. To characterize the salivary glands immune microenvironment of patients with pSS, we performed droplet-based single cell mRNA sequencing (scRNA-seq) (10X Genomics) to provide a deeper insight into the cellular and molecular characteristics of salivary glands from pSS patients.

Methods

11 patients and 5 non-pSS controls were recruited from the The First Affiliated Hospital of USTC. The non-pSS were subjects who had experienced subjective symptoms of dryness, but no not meet any of the classification criteria of pSS. The clinical characteristics and laboratory findings of enrolled patients were also collected. After resection, salivary glands tissue samples were obtained after labial gland biopsy, rapidly digested to a single-cell suspension and subjected to scRNA-seq using the 10X platform. After rigorous quality control (QC) definition, low-quality cells were filtered. Following gene expression normalization for read depth and mitochondrial read count, we applied principle component analysis on genes variably expressed across all 72,853 cell.

Results

A total of 72,853 cells were obtained from all salivary glands samples. Our results revealed 12 major unique cell populations of salivary glands cell, including T cells, B cells, plasma cells, epithelial cells, myoepithelial cells, endothelial cells, myofibroblast, pericytes, melanocytes, fibroblast, myeloid cells and a cluster of unknown cells. As expected, lymphocytes (T and B cell populations) were significant increase in the salivary glands of patients with pSS. For further subsets analysis, we identify 41 subsets, including novel subpopulations in cell types hitherto considered to be homogeneous, as well as transcription factors underlying their heterogeneity. Strikingly, we found that differentially expressed genes (DEGs) that myoepithelial cells uniquely downregulated in pSS patients were involved in regeneration, stem cell population maintenance, cell division, and epithelial cell proliferation. This indicated an impaired stem cell property and regeneration capacity of myoepithelial cells in the SG of pSS patients which may result in the reduction of normal epithelial cells differentiation and proliferation. Our results identified three distinct endothelial subtypes according to the differentially expressed cell markers. ACKR1+ endothelial cells were expanded in the SG of pSS patients which may enhance Leukocyte transendothelial migration. A clear interferon response was observed in most celltypes. We also found a significantly expand PD-1hiCXCR5–CD4+T peripheral helper (Tph), GZMK+CD8+ T cells and a patient-specific fibroblasts in pSS patients. Cellular interaction analysis of SG revealed a strong interaction between epithelial cells and immune cells from pSS patients through CD74-MIF, MIF-TNFRSF14 and HLA-C-FAM3C receptor/ ligand pairs. Chemokine receptors CXCR4 were broadly expressed in SG immune cells implying a potentially central role in cell trafficking.

Conclusion

This resource provides deeper insights into pSS salivary glands immune microenvironment that will be helpful in understanding of the disease heterogeneity and advancing pSS therapy.

Disclosure of Interests

None declared

Dual Functions of MDP Monomer with De- and Remineralizing Ability

Methacryloyloxydecyl dihydrogen phosphate (MDP) has been speculated to induce mineralization, but there has been no convincing evidence of its ability to induce intrafibrillar mineralization. Polymers play a critical role in biomimetic mineralization as stabilizers/inducers of amorphous precursors. Hence, MDP-induced biomimetic mineralization without polymer additives has not been fully verified or elucidated. By combining 3-dimensional stochastic optical reconstruction microscopy, surface zeta potentials, contact angle measurements, inductively coupled plasma-optical emission spectroscopy, transmission electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy with circular dichroism, we show that amphiphilic MDP can not only demineralize dentin by releasing protons as an acidic functional monomer but also infiltrate collagen fibrils (including dentin collagen), unwind the triple helical structure by breaking hydrogen bonds, and finally immobilize within collagen. MDP-bound collagen functions as a huge collagenous phosphoprotein (HCPP), in contrast to chemical phosphorylation modifications. HCPP can induce biomimetic mineralization itself without polymer additives by alternatively attracting calcium and phosphate through electrostatic attraction. Therefore, we herein propose the dual functions of amphiphilic MDP monomer with de- and remineralizing ability. MDP in the free state can demineralize dentin substrates by releasing protons, whereas MDP in the collagen-bound state as HCPP can induce intrafibrillar mineralization. The dual functions of MDP monomer with de- and remineralization properties might create a new epoch in adhesive dentistry and preventive dentistry.

Total bone mineral density is inversely associated with stroke: a family osteoporosis cohort study in rural China

BACKGROUND

The relationship of osteoporosis and stroke is still not fully clarified. Apart from the well-known risk factors for stroke, bone mineral density (BMD) has gained more interest in recent years.

AIM

To further elucidate the relationship between BMD and stroke risk, a prospective cohort study in the Chinese rural population was conducted.

DESIGN

Retrospective analysis of a family osteoporosis cohort.

METHODS

Our subjects were selected from an osteoporosis cohort conducted in Anqing, China. All participants underwent a questionnaire assessment, clinical examinations and laboratory assessments. During the follow-up period, the number of people who had a stroke was recorded. Generalized estimating equation regression analysis was performed to determine the significance of the association between BMD and stroke.

RESULTS

A total of 17868 people were included. A two-way interaction test of sex and BMD on stroke was significant (P = 0.002). There was a significant difference in BMD and stroke morbidity in the male group (P = 0.003). When BMD was assessed as quartiles and the lowest quartile was used as reference, a significantly lower risk for stroke was observed in Q2-4. Notably, no significant difference was observed in female participants with adjusted odds ratio (P > 0.05). The P-value for interaction was calculated. The body mass index (P = 0.014) and waist-to-hip ratio (P = 0.027) were found to be significantly associated with BMD and stroke risk in female participants.

CONCLUSIONS

In Chinese rural areas, total BMD may negatively correlated with stroke, especially in men.

Treatment-related adverse events as predictive biomarkers of efficacy in patients with advanced neuroendocrine tumors treated with surufatinib: results from two phase III studies

Background

No validated biomarkers currently exist for predicting the efficacy outcomes in patients with neuroendocrine tumors (NETs) treated with antiangiogenic therapy. We aimed to evaluate the association between treatment-related adverse events (TRAEs) and efficacy outcomes of surufatinib in patients with advanced NET.

Patients and methods

We included patients with NET treated with surufatinib in two multicenter, randomized, double-blind, placebo-controlled, phase III trials (SANET-p and SANET-ep) in this study. The main exposure was the presence of any of the TRAEs including hypertension, proteinuria, and hemorrhage in the first 4 weeks of surufatinib treatment. The primary outcome of the study was investigator-assessed progression-free survival (PFS). PFS outcomes were estimated using the Kaplan–Meier method with the log-rank test. Hazard ratios (HRs) were calculated by using univariable and multivariable Cox proportional hazard regression models. Blinded independent image review committee (BIIRC) assessments and 4-week landmark analysis were also performed as supportive evaluations.

Results

During the study period, a total of 242 patients treated with surufatinib were included in the analysis, and 164 (68%) patients had at least one of hypertension, proteinuria, and hemorrhage in the first 4 weeks of treatment. The presence of TRAEs in the first 4 weeks was associated with prolonged median PFS [11.1 versus 9.2 months; HR 0.67, 95% confidence interval (CI) 0.47-0.97; P = 0.036]. In multivariable Cox regression analysis, the presence of TRAEs was also significantly associated with longer PFS (HR 0.65, 95% CI 0.44-0.97; P = 0.035). Similar results were obtained in the BIIRC assessments and 4-week landmark analysis.

Conclusions

Treatment-related hypertension, proteinuria, and hemorrhage could be potential biomarkers to predict antitumor efficacy of surufatinib in patients with advanced NET. Future prospective studies are needed to validate the findings.

Trial registration

ClinicalTrials.govNCT02589821; https://clinicaltrials.gov/ct2/show/NCT02589821 and ClinicalTrials.gov NCT02588170; https://clinicaltrials.gov/ct2/show/NCT02588170

•

Treatment-related hypertension, proteinuria, or hemorrhage is associated with longer survival in NETs.

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The association is confirmed by the BIIRC assessments and 4-week landmark analysis.

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TRAEs can be biomarkers to predict antitumor efficacy in patients with NET.

[Initial clinical experience of left bundle branch pacing after transcatheter aortic valve implantation]

Objective: To investigate the efficacy and safety of left bundle branch pacing(LBBP) in patients after transcatheter aortic valve implantation (TAVI). Methods: This is a retrospective study. A total of 35 patients underwent TAVI and received pacemaker implantation from January 2018 to December 2020 in Beijing Fuwai Hospital were enrolled. Patients were divided into LBBP group (n=12) and right ventricular apex pacing (RVAP) group (n=23) according to the pacing position. The success rate of operation in LBBP group was calculated, and the occurrence of complications were observed, and the parameters of pacemaker were measured on the 3rd day and 1, 3 and 6 months after operation. The N-terminal pro-B-type natriuretic peptide (NT-proBNP), echocardiographic and ECG indexes were compared between the two groups on the 3rd day and 1, 3, and 6 months after pacemaker implantation. Result: A total of 35 patients were included, The age was (76.4±7.7) years, including 19 males (54.3%). The procedure time ((86.58±17.10)min vs. (68.74±9.18)min, P<0.001) and fluoroscopy duration ((20.08±4.44)min vs. (17.00±2.26)min, P<0.001) were significantly longer in LBBP group compared with RVAP group. The operation success rate of LBBP group was 11/12. There was no serious operation related complications such as pneumothorax, hemothorax, electrode dislocation, infection, and lower limb bleeding. The patients were followed up for 7.43 (5.21, 9.84) months. The programmed parameters of pacemaker were in the ideal range and stable during follow-up. At 3 and 6 months after operation, the left ventricular ejection fraction in LBBP group was higher than that in RVAP Group (at 3 months: (60.75±2.89)% vs. (57.35±3.33)%, P=0.004; at 6 months: (63.17±3.33)% vs. (56.17±3.97)%, P<0.001), NT-proBNP values was lower in LBBP group than that in RVAP Group (at 3 months: 822 (607, 1 150)ng/L vs. 1 052 (902, 1 536)ng/L, P=0.006; at 6 months: 440 (330,679)ng/L vs. 783 (588, 1 023)ng/L, P=0.001). At 1, 3 and 6 months after operation, the QRS duration was shorter in LBBP group than that in RVAP group (1 month: 99 (97, 107)ms vs. 126(124, 130)ms, P<0.001; 3 months: 98(96, 105)ms vs. 129(128, 133)ms, P<0.001; 6 months: 96(94, 104)ms vs. 130(128, 132)ms, P<0.001). Conclusions: For patients with permanent pacemaker indications after TAVI, LBBP is feasible, safe and reliable. It could improve the cardiac function in the short term, the long-term effect of LBBP needs to be further observed.

Need to Belong and Social Ties in Late Life

According to socioemotional selectivity theory, older adults are more selective and tend to shrink their social network to their closest ties. However, a heightened need to belong, which is characterized by a stronger desire for acceptance and motivation to affiliation, may alter this common pattern. We know little about how the need to belong shapes social network structure, especially in late life. This study investigated the associations between the need to belong, size of social network, and engagement with social ties among older adults. Participants (N = 314) aged over 65 years from the Daily Experiences and Well-being Study completed a baseline interview regarding their close ties (i.e., social convoy members), and weak ties, as well as a self-report measure of need to belong. They completed ecological momentary assessment (EMA) surveys reporting their social encounters every 3 hours over 5 to 6 days. Need to belong was unrelated to the number of close ties. In contrast, participants with a higher need to belong reported more less close (but still important) ties and weak ties than those with a lower need to belong, but spent a similar amount of time (i.e., proportion of EMA involving social encounters) with either their close ties or weak ties. These results suggest that the need to belong may motivate older adults to go beyond their closest ties to weaker ties, and highlight the discrepancies between the sense of being connected to social partners and the actual engagement with them in this process.

Digital guides to facilitate retained root removal and simultaneous implant placement

The aim of this study was to report the use of digital guides to locate impacted residual roots (IRR) (location guide) and to simultaneously insert dental implants (surgical guide). This case series included five patients. The IRR was first removed through a lateral window approach using the digital location guide, then the implant was placed simultaneously with the implant surgical guide. Definitive restorations were completed after a 6-month healing period. An average of 13.0 ± 3.1 minutes was required to locate the IRR. The implant stability quotient (ISQ) was obtained during surgery and before digital coping using a non-invasive resonance frequency measurement. The average ISQ during surgery for the five dental implants was 60.2 ± 6.3, and the value increased to 66.6 ± 4.8 before final restoration. The average deviations at the implant neck and root apex were 0.48 ± 0.25 mm and 0.74 ± 0.46 mm, respectively. The average angular deviation was 3.5 ± 1.4°. Bone resorption at the implant neck was a mean 0.072 ± 0.041 mm before final restoration. All implants functioned well at 1 year after final restoration. The application of surgical guides in the extraction of IRR enabled crestal bone preservation and simultaneous implant placement.

RNA interference in Pardosa pseudoannulata, an important predatory enemy against several insect pests, through ingestion of dsRNA-expressing Escherichia coli

RNA interference is an important technology for gene functional research in many organisms. The pond wolf spider (Pardosa pseudoannulata) is an important natural enemy of rice field pests. To facilitate large-scale gene functional research in this spider species and others, we developed an RNA interference (RNAi) method via ingestion of bacteria expressing dsRNA. The dsRNA targeting a cytochrome P450 monooxygenase (cyp41g2) was expressed in Escherichia coli HT115 (DE3). And then the bacterial suspension was fed to 14-20 days old spiderlings. The mRNA abundance of the target gene was significantly reduced after 3-day's ingestion of bacteria expressing dsRNA, and between day 5 and 7, RNAi efficiency remained stable. Thus, we selected 5 days as the optimum interference time. Furthermore, the bacteria resuspension containing 20 ng/μl dsRNA was selected as the optimum concentration. To evaluate the applicability of this method, three other genes with different tissue expression pattern were also selected as targets. And the mRNA abundance of all the four target genes was significantly reduced with RNAi efficiency between 66.0% and up to 86.9%. The results demonstrated that the oral delivery of bacteria expressing dsRNA would be an effective RNAi method for the gene functional study in P. pseudoannulata.

[Mage-D1 binding to activated p75NTR positively regulates mineralization of rat ectomesenchymal stem cells in vitro]

OBJECTIVE

To detect the binding of Mage-D1 with activated p75NTR and explore their role in regulating mineralization of ectomesenchymal stem cells (EMSCs).

METHODS

EMSCs were isolated from the tooth germs of embryonic SD rats (19.5 days of gestation) by tissue explant culture and were identified for surface markers using flow cytometry. The cultured cells were divided into blank control group, 100 ng/mL nerve growth factor (NGF) stimulation group, and lentivirus-mediated Mage-D1 interference (SH-Mage-D1) group. Proximity ligation assay was used to detect the binding of Mage-D1 with activated p75NTR in the EMSCs, and the binding strength was compared among the 3 groups. Alizarin red staining and ALP staining were used to observe mineralization of the induced cells. The expressions of ALP, Runx2, OCN, BSP, OPN, Msx1 and Dlx1 at both the mRNA and protein levels were detected using RT-PCR and Western blotting.

RESULTS

The isolated EMSCs expressed high levels of cell surface markers CD44, CD90, CD29, CD146, and CD105 with a low expression of CD45. The results of proximity ligation assay showed that the binding of Mage-D1 with activated p75NTR in the cells increased over time, and the binding strength was significantly greater in NFG-treated cells than in the cells in the other two groups (P < 0.05). Alizarin red staining and ALP staining of the induced cells showed that the changes in the mineralization nodules were consistent with those of ALP activity. The cells treated with 100 ng/mL NGF exhibited significantly increased expressions of ALP, Runx2, OCN, BSP, OPN, Col1, Msx1 and Dlx1 as compared with the cells in the other two groups (P < 0.05).

CONCLUSION

Mage-D1 directly binds to activated p75NTR in embryonic rat EMSCs to positively regulate the mineralization of the EMSCs.

[Activation of mir-30a-wnt/β-catenin signaling pathway upregulates cathepsin K expression to promote cementogenic differentiation of periodontal ligament stem cells]

OBJECTIVE

To explore the role of cathepsin K (CTSK) regulated by mir-30a-wnt/β-catenin signaling pathway in cementogenic differentiation of periodontal ligament stem cells (PDLSCs).

METHODS

Human PDLSCs isolated by limiting dilution culture were induced by enamel matrix protein derivative (EMD) for differentiation into cementoblast-like cells. MicroRNA chip technique was employed to screen the differentially expressed microRNAs in the cells during induced differentiation. The effect of inhibiting miR-30a on CTSK expression in the induced cells was examined using RT-PCR and Western blotting. Ceramic scaffolds coated with PDLSCs treated with EMD and transfected with the miR-30a inhibitor or a lentiviral vector for CTSK overexpression were prepared and implanted subcutaneously in nude mice, and 8 weeks later the cellular expressions of cementoblast markers CAP and CEMP-1 were detected with immunohistochemistry to verify whether CTSK participate in cementogenic differentiation of PDLSCs. The role of wnt signaling pathway in miR-30a-mediated regulation of CTSK expression was explored by examining CTSK protein expressions after blocking wnt signaling in PDLSCs.

RESULTS

In PDLSCs with EMD-induced differentiation into cementoblast-like cells, multiple microRNAs exhibited differential expressions; and among them, miR-30a was specifically and significantly up-regulated (P < 0.05). Up-regulation of miR-30a obviously increased the expression of CTSK (P < 0.05) and promoted PDLSCs to form cementum-like tissues with high expressions of CAP and CEMP-1. The regulatory effect of miR-30a on CTSK expression was obviously attenuated after inhibiting wnt/β-catenin signaling pathway.

CONCLUSION

EMD induces cementogenic differentiation of PDLSCs possibly by up-regulating the expression of miR-30a, which further activates the wnt/β-catenin signaling pathway to enhance the expression of CTSK.

Erythrocytes induce vascular dysfunction in COVID-19

Background

Vascular injury has been implicated as a major cause of clinical complications in patients with coronavirus disease 2019 (COVID-19). Autopsy studies have revealed destruction of the endothelial cell lining, which might explain cardiovascular alterations arising from the infection. However, data demonstrating endothelial dysfunction during ongoing infection are sparse, and the underlying mechanisms are still largely unknown. Red blood cells (RBCs) are affected by COVID-19 with alterations in their structure and function, possibly contributing to vascular injury via increased oxidative stress.

Purpose

To determine the presence of endothelial dysfunction in patients with COVID-19 and to explore the RBC as a possible mediator of such dysfunction.

Methods

The study was performed on 17 patients hospitalized for moderate COVID-19 infection and age- and sex-matched healthy subjects. Inclusion criteria of the COVID-19 patients were PCR-verified SARS-CoV2 infection, pulmonary infiltrates on x-ray, oxygen demand during hospital stay and ≤ one cardiovascular co-morbidity. Microvascular endothelial function in vivo was assessed with a pulse amplitude tonometry device on each index finger at baseline and during reactive hyperemia and expressed as reactive hyperemia index (RHI). RBCs from COVID-19 patients (C19-RBCs) and healthy subjects (H-RBCs) were incubated with isolated rat aortic segments for evaluation of endothelium-dependent and -independent relaxation.

Results

COVID-19 patients displayed profound impairment in endothelial function in vivo with RHI 1.56 (1.30–1.81, median and interquartile range) compared to healthy subjects 2.36 (1.97–2.79, p&lt;0.001). C19-RBCs induced severe impairment in both endothelium-dependent (27% maximal relaxation) and -independent relaxations (54%) compared to H-RBCs (67% and 95% relaxation, respectively). Further, C19-RBCs induced upregulation of vascular arginase 1 (∼2 fold increase compared to H-RBCs) and markers of oxidative stress (∼6 fold). Consequently, inhibition of vascular arginase or superoxide attenuated the impairment in endothelial function induced by C19-RBCs. C19-RBCs were characterized by increased production of reactive oxygen species (∼1.4 fold) and reduced export of the nitric oxide metabolite nitrate. Following pre-incubation with interferon-γ, but not interleukin-6 or tumor necrosis factor-α, H-RBCs induced impairment in endothelial function.

Conclusions

This study demonstrates the presence of marked endothelial dysfunction in an otherwise mainly healthy patient group hospitalized for COVID-19, and clearly implicates a central role of the RBC as a mediator of endothelial injury through enhancement of reactive oxygen species and arginase. These data shed light on a new pathological mechanism underlying vascular dysfunction in COVID-19 patients and may lay the foundation for future therapeutic developments.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Swedish Heart and Lung foundationSwedish Research Council

Attenuated cardiac post-ischemic injury and endothelial dysfunction by stimulation of soluble guanylyl cyclase in red blood cells from patients with type 2 diabetes

Background

Reduced bioavailability of nitric oxide (NO) contributes to ischemic heart disease in type 2 diabetes (T2D). Red blood cells (RBCs) are known to produce NO bioactivity and to contain a functional soluble guanylyl cyclase (sGC) that is activated by NO. Recent studies revealed that RBCs from patients with T2D exacerbates ischemia-reperfusion (I/R) injury and induces endothelial dysfunction via a mechanism that is dependent on reduced export of NO bioactivity from RBCs. It remains unknown whether stimulation of sGC in RBCs from patients with T2D protects against myocardial I/R injury and endothelial dysfunction.

Purpose

To test the hypothesis that stimulation of sGC in RBCs from T2D patients protects against myocardial I/R injury and improves endothelial function.

Methods

RBCs collected from T2D patients and healthy subjects were incubated with vehicle or the sGC stimulator CYR715 before being administered to isolated Langendorff-perfused rat hearts subjected to 25 min global ischemia and 60 min reperfusion. Left ventricular developed pressure (LVDP) and infarct size were determined. In addition, isolated rat aortic rings were incubated with RBCs subsequent determination of endothelium-dependent relaxation (EDR).

Results

Administration of RBCs from T2D patients impaired post-ischemic recovery of LVDP and induced endothelial dysfunction in comparison with RBCs from healthy subjects (P&lt;0.001). Pre-incubation of RBCs from patients with T2D with CYR715 prior to administration to the isolated heart enhanced the recovery of LVDP (Fig.1A), reduced infarct size (Fig.1B), and attenuated endothelial dysfunction (Fig.1C). CYR715 did not induce cardioprotection in the absence of RBCs. The sGC inhibitor ODQ did not significantly affect cardiac recovery per se but totally abolished the protective effect of CYR715 (Fig.1A).

Conclusions

Stimulation of sGC in RBCs from patients with T2D protects against cardiac I/R injury and prevents development of endothelial dysfunction. Stimulation of the NO-sGC pathway in RBCs appears to be an attractive therapeutic strategy to prevent cardiovascular injury in T2D.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Swedish Heart and Lung Foundation, the Swedish Research Council

Soft-Dielectron Excess in Proton-Proton Collisions at sqrt[s]=13 TeV

A measurement of dielectron production in proton-proton (pp) collisions at sqrt[s]=13  TeV, recorded with the ALICE detector at the CERN LHC, is presented in this Letter. The data set was recorded with a reduced magnetic solenoid field. This enables the investigation of a kinematic domain at low dielectron (ee) invariant mass m_{ee} and pair transverse momentum p_{T,ee} that was previously inaccessible at the LHC. The cross section for dielectron production is studied as a function of m_{ee}, p_{T,ee}, and event multiplicity dN_{ch}/dη. The expected dielectron rate from hadron decays, called hadronic cocktail, utilizes a parametrization of the measured η/π^{0} ratio in pp and proton-nucleus collisions, assuming that this ratio shows no strong dependence on collision energy at low transverse momentum. Comparison of the measured dielectron yield to the hadronic cocktail at 0.15<m_{ee}<0.6  GeV/c^{2} and for p_{T,ee}<0.4  GeV/c indicates an enhancement of soft dielectrons, reminiscent of the "anomalous" soft-photon and soft-dilepton excess in hadron-hadron collisions reported by several experiments under different experimental conditions. The enhancement factor over the hadronic cocktail amounts to 1.61±0.13(stat)±0.17(syst,data)±0.34(syst,cocktail) in the ALICE acceptance. Acceptance-corrected excess spectra in m_{ee} and p_{T,ee} are extracted and compared with calculations of dielectron production from hadronic bremsstrahlung and thermal radiation within a hadronic many-body approach.

Characterization of serum adiponectin and leptin in healthy perinatal dairy cows or cows with ketosis, and their effectson ketosis involved indices

We investigated changes in concentrations of ADP (adiponectin), LEP (leptin), BHBA (beta-hydroxybutyric acid), NEFA (non-esterified fatty acid), Glucose (Glu) and INS (insulin) in serum of healthy perinatal dairy cows and cows with ketosis. Twenty-one healthy cows and seventeen cows with ketosis from a herd of a total 60 Holstein cows (near dry period i.e. 56 days antepartum) were selected. Blood was collected through the tail vein every 7 days, from 56 day antepartum to 56 day postpartum. Serum ADP, LEP, BHBA, NEFA, Glu, and INS concentrations were determined, and ketosis was diagnosed through serum BHBA (≥1.2 mmol/L). We showed the concentration of serum adipokines and energy balancing indices were stable during antepar- tum period. However, ADP concentration increased while LEP decreased, and there were a significant increase in cows with ketosis compared to that of in healthy cows. Serum BHBA and NEFA concentrations increased significantly at first, and then gradually decreased in both healthy cows and cows with ketosis. However, cows with ketosis showed higher concentrations of BHBA and NEFA which restored later. The serum concentration of Glu in both healthy dairy cows and cows with ketosis showed a decreasing trend. INS concentration in healthy cows was decreased while it was increased in cows with ketosis. The results reflect the extent of hypo- glycemia and lipid mobilization postpartum, suggest IR exists in cows with ketosis while serum ADP and LEP might play roles in the development of ketosis.

Differential Associations Between Parents' Versus Children's Perceptions of Parental Socialization Goals and Chinese Adolescent Depressive Symptoms

Although prior studies have demonstrated the associations between parental socialization goals and parenting practices, as well as parenting practices and adolescent depressive symptoms, respectively, research examining the comprehensive developmental pathways among these constructs (i. e., the path from parental socialization goals to parenting practices to adolescent depressive symptoms) is scarce, especially in the Chinese context. Grounded in the integrative model of parenting, this study investigated the associations between parental socialization goals and adolescent depressive symptoms by examining the indirect pathways through parents' autonomy support and psychological control as well as the moderating effect of educational stage. In Study 1, 345 Chinese adolescents and their primary caregivers completed a measure on parental socialization goals. Adolescents also reported on their depressive symptoms. Results showed that children who reported more self-development parental goals showed fewer depressive symptoms. However, parents' reports of goals or child-parent perceptual discrepancies were not related to children's depressive symptoms. Drawing on this finding, 424 middle school and 301 high school Chinese adolescents completed measures regarding parental socialization goals, autonomy support, psychological control, and their own depressive symptoms in Study 2. Results showed that parental autonomy support linked the associations of self-development and achievement-oriented parental goals and children's depressive symptoms among middle school students, whereas parental psychological control linked such associations among high school students. Our findings provide a more holistic view on how parents' socialization goals are related to children's depressive symptoms via their parenting practices. We also discussed the practical implications for the clinical work regarding adolescent depressive symptoms.