Outcomes and phenotypic expression of rare variants in hypertrophic cardiomyopathy genes in over 200,000 adults

Background

Hypertrophic cardiomyopathy (HCM) is caused by rare variants in sarcomere-encoding genes, but little is known about the clinical significance of these variants in the general population.

Purpose

To determine the population prevalence of HCM-associated sarcomeric variants, characterise their phenotypic manifestations, estimate penetrance, and identify associations between sarcomeric variants and clinical outcomes, we performed an observational study of 218,813 adults in the UK Biobank (UKBB), of whom 200,584 have whole exome sequencing (WES).

Methods

We carried out an integrated analysis of WES and cardiac magnetic resonance (CMR) imaging in UK Biobank participants stratified by sarcomere-encoding variant status. Computer vision techniques were used to automatically segment the four chambers of the heart (Figure 1). Cardiac motion analysis was used to derive strain and strain rates. Regional analysis of left ventricular wall thickness was performed using three-dimensional modelling of these segmentations.

Results

Median age at recruitment was 58 (IQR 50–63 years), and participants were followed up for a median of 10.8 years (IQR 9.9–11.6 years) with a total of 19,507 primary clinical events reported.

The prevalence of rare variants (allele frequency <0.ehab724.17314) in HCM-associated sarcomere-encoding genes in 200,584 participants was 2.9% (n=5,727; 1 in 35), and the prevalence of pathogenic or likely pathogenic variants (SARC-P/LP) was 0.24% (n=474, 1 in 423).

SARC-P/LP variants were associated with increased risk of death or major adverse cardiac events (MACE) compared to controls (HR 1.68, 95% CI 1.37–2.06, p<0.001), mainly due to heart failure endpoints (Figure 2: cumulative hazard curves with zoomed plots for lifetime risk of A) death and MACE or B) heart failure, stratified by genotype; genotype negative (SARC-NEG), carriers of indeterminate sarcomeric variants (SARC-IND) or SARC-P/LP; C) Forest plot of comparative lifetime risk of clinical endpoints by genotype).

While males had a higher overall risk of adverse outcomes, the incremental genetic risk from SARC-P/LP mutations was greater in females (HR for females: 2.18 CI 1.65–2.89, p<0.001; HR for males: 1.42 CI 1.05–1.9, p=0.02).

In 21,322 participants with CMR, SARC-P/LP were associated with asymmetric increase in left ventricular maximum wall thickness (10.9±2.7 vs 9.4±1.6 mm, p<0.001) but hypertrophy (≥13mm) was only present in 16% (n=7/43, 95% CI 7–31%). Other rare sarcomere-encoding variants had a weak effect on wall thickness (9.5±1.7 vs 9.4±1.6 mm, p=0.002) with no combined excess cardiovascular risk.

Conclusions

In the general population, SARC-P/LP variants have low aggregate penetrance for overt HCM but are associated with increased risk of adverse cardiovascular outcomes and a sub-clinical cardiomyopathic phenotype. Although absolute event rates are low, identification of these variants may enhance risk stratification beyond familial disease.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The study was supported by the Medical Research Council, UK (MC-A651-53301); National Institute for Health Research (NIHR) Imperial College Biomedical Research Centre; NIHR Royal Brompton Cardiovascular Biomedical Research Unit; British Heart Foundation (NH/17/1/32725, RG/19/6/34387, RE/18/4/34215).

Deep learning for automatic calcium scoring in population based cardiovascular screening

Background

High volumes of standardized coronary artery calcium (CAC) scans are generated in screening that need to be scored accurately and efficiently to risk stratify individuals.

Purpose

To evaluate the performance of deep learning based software for automatic coronary calcium scoring in a screening setting.

Methods

Participants from the Robinsca trial that underwent low-dose ECG-triggered cardiac CT for calcium scoring were included. CAC was measured with fully automated deep learning prototype and compared to the original manual assessment of the Robinsca trial. Detection rate, positive Agatston score and risk categorization (0–99, 100–399, ≥400) were compared using McNemar test, ICC, and Cohen's kappa. False negative (FN), false positive (FP) rate and diagnostic accuracy were determined for preventive treatment initiation (cut-off ≥100 AU).

Results

In total, 997 participants were included between December 2015 and June 2016. Median age was 61.0 y (IQR: 11.0) and 54.4% was male. A high agreement for detection was found between deep learning based and manual scoring, κ=0.87 (95% CI 0.85–0.89). Median Agatston score was 58.4 (IQR: 12.3–200.2) and 61.2 (IQR: 13.9–212.9) for deep learning based and manual assessment respectively, ICC was 0.958 (95% CI 0.951–0.964). Reclassification rate was 2.0%, with a very high agreement with κ=0.960 (95% CI: 0.943–0.997), p<0.001. FN rate was 0.7% and FP rate was 0.1% and diagnostic accuracy was 99.2% for initiation of preventive treatment.

Conclusion

Deep learning based software for automatic CAC scoring can be used in a cardiovascular CT screening setting with high accuracy for risk categorization and initiation of preventive treatment.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Robinsca trial was supported by advanced grant of European Research Council

[Effects of ambient particulate matter (PM10) on prevalence of diabetes and fasting plasma glucose]

Objective: To explore the effect of long-term exposure to ambient particulate matter (PM₁₀) on the prevalence of diabetes and fasting plasma glucose (FPG). Methods: The subjects of the study were from the baseline population of "Jinchang Cohort", and 24 285 subjects were finally included after excluding incomplete home address information and diabetic diagnosis information. The demographic characteristics, lifestyle and health status of the survey subjects were collected through questionnaire, physical examination and laboratory tests. ArcGIS software was used to match the nearest environmental monitoring stations for each subject according to residential address. Two-year average concentrations of PM₁₀ were calculated to estimate exposure level. The logistic regression and the multiple linear regression were conducted to assess the effects of ambient PM₁₀ on the prevalence of diabetes and FPG. The restricted cubic spline was used to quantify the dose-response relationship. Stratified analysis and effect modification analysis were also performed. Results: The age of 24 285 participants was (49.32±8.60) years, and the BMI was (24.22±6.09) kg/m². There were 13 950 (57.44%) males and 2 066 (8.51%) diabetic patients. After adjusting for confounders, for every 10 μg/m³ increase in the average PM₁₀ concentration in the first two years of the survey, the prevalence of diabetes increased [OR (95%CI) =1.05 (1.01-1.09)]and the FPG level elevated [β (95%CI) = 0.061 (0.047-0.076) mmol/L]. The results of the restricted cubic spline analysis showed a nonlinear relationship between PM₁₀ concentration and FPG level (P<0.001). Further subgroup analysis showed that female [OR (95%CI) =1.10 (1.03-1.18)], people over 50 years old [OR (95%CI) =1.06 (1.02-1.11) ], subjects with family history of diabetes [OR (95%CI) = 1.13 (1.04-1.23) ], and with hypertension [OR (95%CI) = 1.07 (1.02-1.12) ] had a stronger association between the prevalence of diabetes and PM₁₀ exposure (all P interaction values were<0.05). The effects of PM₁₀ on FPG were more significant in people older than 50 years[β (95%CI) = 0.080 (0.050-0.109) mmol/L], with family history of diabetes [β (95%CI) = 0.087 (0.036-0.137) mmol/L], and hypertension [β (95%CI) = 0.077 (0.046-0.108) mmol/L] (all P interaction values were<0.05). Conclusions: Long-term exposure to ambient PM₁₀ increases the diabetes prevalence and FPG. People older than 50 years old, with family history of diabetes and hypertension could be more sensitive to the effects of PM₁₀ exposure.

[Screening and analysis of Treponema pallidum specific antibody among childbearing age people in rural areas of Yunnan province, 2013-2017]

Objective: To determine the prevalence, epidemiological characteristics, and related factors of syphilis infection among rural childbearing age people to promote medical interventions on pre-pregnancy aristogenesis and syphilis infection in Yunnan province. Methods: The subjects in this study were 18-49-year-old rural couples of childbearing age from the National Free Preconception Health Examination Project in Yunnan province during 2013-2017. The descriptive study was carried out to determine the positive rate of Treponema pallidum specific antibody (TPsAb) and related sociodemographic characteristics. Results: The overall positive rate of TPsAb was 0.38% (8 204/2 160 455) in 2 160 455 rural childbearing age people in Yunnan. The positive rate of TPsAb was 0.39% (4 019/1 040 981) in men,higher than that in women (0.37%,4 185/1 119 474). The positive rate of TPsAb was highest in the age group 45-49 years (0.70%,158/22 511). The positive rate of TP antibody in the minority ethnic groups and Han ethnic groups appeared the same (0.38%). However,the highest positive rate of TPsAb was 0.77% (461/60 153) in Hani ethnic group among all the 17 minority ethnic groups. People with education level of primary education had the highest anti-TP positive rate (0.54%,2 327/431 275). The positive rate of TPsAb appeared the highest in Zhaotong (0.73%, 2 049/281 614) area among all the 16 prefectures of the province. The positive rate of TPsAb in the population from the impoverished regions (0.50%,2 963/590 039) was higher than in other disadvantaged areas (0.34%, 3 115/929 368) or areas with average income (0.33%,2 126/641 048). Significant differences appeared in the positive rate of TPsAb among populations of different ages, ethnic, education level, and economic level groups (trend χ² test, P<0.001). Conclusions: The positive rate of TP antibody in rural childbearing age people in Yunnan was related to multi factors,including sex,age,ethnic group,education level,area, residence, and local economic situation. The positive rate of TPsAb was higher in men than in women. And people with elder age, lower education level, being Hani or Lahu ethnic group, and Zhaotong areas had higher TPsAb positive rates and higher syphilis infection risk.

[Relapse of ankylosing spondylitis and its predictors after withdrawal of tumor necrosis factor-α inhibitors: a 52-week follow-up study]

OBJECTIVE

To investigate the recurrence of ankylosing spondylitis (AS) that has been relieved by standard-dose adalimumab (ADA) after dose reduction or withdrawal of tumor necrosis factor-α inhibitor (TNFi) and explore the factors that predict AS occurrence.

OBJECTIVE

This study was conducted among 63 patients with AS who reduced the dose of or discontinued TNFi after completing at least 12 treatment cycles with ADA (40 mg/2 weeks) to achieve ASAS20 improvement with a BATH disease activity index (BASDAI) < 4 for more than 8 weeks. The patients were followed up every 12 weeks for a total of 52 weeks, and the recurrence of AS, changes of BASDAI, C-reactive protein (CRP)-based disease activity score (ASDASCRP), low back pain (LBP) score, Bath Ankylosing Spondylitis Metrology Index (BASMI), CRP and ESR were recorded and analyzed. Cox regression model and ROC curve analyses were performed to analyze the risk factors of AS relapse after dose reduction or discontinuation of TNFi.

OBJECTIVE

Of the 63 patients enrolled, 57 completed the follow-up study, among whom 22 (38.6%) patients experienced AS relapse within 52 weeks, with a median clinical recurrence time of 31 weeks. The recurrence rate of AS was significantly higher in patients with complete withdrawal of medications (89.0%) than in those with TNFi dose reduction and TNFi discontinuation (P < 0.001), and did not differ significantly between the latter two groups of patients (χ²= 0.071, P=0.791). The Cox regression model showed that a high baseline LBP score (HR=1.438, P=0.027) and a high BASMI score (HR=1.29, P=0.049) were the risk factors for AS recurrence after TNFi dose reduction or discontinuation, while maintenance of medication during follow-up was a protective factor (HR=0.209, P=0.001). ROC curve analysis showed that the combination of baseline LBP score, BASMI and medication during follow-up had a good predictive value for AS relapse (AUC=0.819) with a sensitivity of 0.772 and a specificity of 0.718.

OBJECTIVE

Dose reduction or discontinuation of TNFi is associated with a high recurrence rate of AS that has been relieved by TNFi treatment. A high LBP score, a high BASMI score and discontinuation of maintenance medication are the risk factors for AS recurrence in patients after dose reduction or withdrawal of TNFi.

POS0081 CLINICAL FEATURES OF PEDIATRIC BEHÇET’S DISEASE IN CHINA

Background:

Behçet’s disease (BD) is a systemic inflammatory disease involving primarily the oral and genital mucosa, skin and eyes. Some patients exhibit broader involvement with multi-organ system inflammation, causing significant morbidity and mortality. With much of the literature focused on adult-onset BD, the clinical spectrum of BD in children is not well studied. The diagnosis of pediatric BD is difficult to make due to its rarity in childhood, the paucity of experience among pediatricians and the lack of validated diagnostic criteria.

Objectives:

We aim to describe the clinical characteristic of children with Behçet’s disease in China.

Methods:

We performed a cross-sectional cohort analysis of patients with BD recruited between June 2017 and May 2020. We enrolled a total of 848 patients with pediatric BD (onset prior to age 18 years) and 1531 patients with adult-onset BD. Clinical data were collected by retrospective chart review.

Results:

From a cohort of 848 patients with pediatric BD (412 males, 436 females), the average age of disease onset was 11.59 ± 4.11 years and the earliest case was appeared the first symptom at 7 months of age. Clinical manifestations in this group included recurrent oral aphtosis (100%), genital ulcers (77.71%), ocular involvement (30.19%), skin involvement (63.56%), neurological involvement (4.60%), gastrointestinal involvement (20.05%), vascular involvement (9.79%), heart valve involvement (3.66%), arthritis / arthralgia (32.43%), fever (0.35%) and positive pathergy test (21.11%; Table 1). The prevalence of these clinical findings was largely similar to that of adult BD patients with the exception of mild differences in the frequency of gastrointestinal, heart valve, joint involvement and fever. However, the time from symptom onset to diagnosis was significantly longer in children with BD compared to adults (13.34±9.13 years vs. 6.73±33.21 years, P<0.001). The most common initial symptom in pediatric BD was recurrent oral aphtosis (91.57% vs. 86.28% in adults, P<0.001).

In the pediatric group, clinical manifestations also differed between males and females. In addition to oral ulcers, the most common clinical manifestations in male patients were ocular involvement (42.23%), vascular involvement (15.53%), heart valve involvement (5.10%) and epididymitis (9.95%). Among female patients, the frequency of genital ulcers is significantly higher than that of men (86.24% vs. 68.69%, P<0.001).

Conclusion:

We described the clinical characteristics of a large cohort of pediatric BD patients in China. While the clinical manifestations are largely similar to adult BD, the time from symptom onset to diagnosis is significantly delayed in pediatric patients. Our study highlights the need to improve awareness of BD among pediatric providers to facilitate rapid diagnosis and treatment in children.

References:

[1]Yildiz et al. Pediatric Behçet’s disease- clinical aspects and current concepts. Eur J Rheumatol 2020; 7(Suppl 1): S38-S47.

[2]Koné-Paut. Behçet’s disease in children, an overview. Pediatric Rheumatology (2016) 14:10.

Table 1.

Comparison of clinical features of BD in children and adults

Children(n=848)Adult(n=1531)PAge of first symptom (y)11.59±4.1127.08±7.91Sex(M/F)412/436Years of diagnosis (y)13.34±9.136.73±33.21<0.001Recurrent oral aphthosis848 (100%)1518 (99.15%)0.007Genital Ulcers659 (77.71%)1891152 (75.24%)3790.176Ocular signs256 (30.19%)592508 (33.18%)10230.134Cutaneous signs539 (63.56%)3091020 (66.62%)5110.132Neurological signs39 (4.60%)80982 (5.36%)14490.421Gastrointestinal signs170 (20.05%)678244 (15.94%)13870.001Vascular signs83 (9.79%)765162 (10.58%)13690.542Heart valve signs31 (3.66%)817110 (7.18%)1421<0.001Joint signs275 (32.43%)573612 (39.97%)919<0.001Fever3 (0.35%)84522 (1.44%)15090.013Positive pathergy test179 (21.11%)669347 (22.66%)11840.381

Acknowledgements:

China Behcet’ Disease Patients Assossiation.

Disclosure of Interests:

None declared.

POS0833 A RETROSPECTIVE COHORT STUDY IN CHINESE PATIENTS WITH ADULT POLYMYOSITIS AND DERMATOMYOSITIS: RISK OF COMORBIDITIES AND SUBCLASSIFICATION USING MACHINE LEARNING

Background:

Idiopathic inflammatory myopathy (IIM), also known as myositis, refers to a group of heterogeneous disorders including polymyositis (PM), dermatomyositis (DM), inclusion body myositis and immune-mediated necrotising myopathy. Phenotype, pathogenesis, and prognosis vary due to multi-organ involvement and comorbidities. With the clinical application of MSAs, a new classification system for myositis was explored to reduce confusion between subgroups. But it is far from showing the full picture of myositis due to high heterogeneity. Therefore, it is necessary to systematically evaluate the relevant risk factors of myositis for ILD, other rheumatic diseases, and malignancy for better clinical vigilance. And further exploring the subclassification of myositis is critical.

Objectives:

To identify the risk factors in Chinese patients with adult polymyositis and dermatomyositis for their comorbidities and explore a subclassification system.

Methods:

Clinical records of 397 patients with idiopathic inflammatory myopathies were retrospectively reviewed. Logistic regression was used to identify potential risk factors for interstitial lung disease (ILD), other rheumatic diseases, and malignancy after bivariate analysis. Hierarchical clustering and decisional tree were utilized to identify subgroups and explore a subclassification system.

Results:

A total of 119 polymyositis and 191 dermatomyositis patients were included. Anti-PM/Scl, anti-Ro52, anti-aminoacyl-tRNA synthetase and anti-MDA5 (adjusted odds ratios (AOR)=4.779, 1.917, 5.092 and 7.714 respectively) antibodies were risks (p<0.05), whereas overlapping malignancy was protective (AOR=0.107; p=0.002) for ILD across polymyositis, dermatomyositis and the total group. In subgroup models, Raynaud’s phenomenon, arthralgia and semi-quantitative anti-nuclear antibody (AOR=51.233, 4.261, 3.047 respectively) were risks for other overlapping rheumatic diseases (p<0.05). For overlapping malignancy, male and anti-TIF1γ antibodies (AOR=2.533, 16.949) were risks (p<0.05), whereas disease duration and combination of ILD (AOR=0.954, 0.106) were protective in the total group (p<0.05); while anti-NXP2 antibodies were identified as risk factors (AOR=73.152; p=0.038) in polymyositis. Hierarchical clustering suggested a subclassification with 6 subgroups: malignancy overlapping dermatomyositis, classical dermatomyositis, polymyositis with severe muscle involvement, dermatomyositis with ILD, polymyositis with ILD, and overlapping of myositis with other rheumatic diseases according to the characteristics of grouped patients. Accuracy of the classification and regression trees model was 0.768 (95% CI 0.711 to 0.819) on training set and 0.633 (95%CI 0.499 to 0.754) on test set.

Conclusion:

Accompanying ILD, other rheumatic diseases and malignancy are strongly associated with clinical manifestation and myositis-specific or myositis-associated autoantibodies among Chinese polymyositis and dermatomyositis patients. The subclassification system proposed a more precise phenotype defining toward stratified treatments.

Acknowledgements:

The study was supported by the Natural Science Foundation of China [No. 81803932] and the Natural Science Foundation of Guangdong Province [No. 2018030310025 and 2017A030313868]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Disclosure of Interests:

None declared

Dynamic programming for solving a simulated clinical scenario of sepsis resuscitation

BACKGROUND

A major challenge in clinical research is population heterogeneity and we need to consider both historical response and current condition of an individual in considering medical decision making. The idea of precise medicine cannot be fully accounted for in traditional randomized controlled trials. Reinforcement learning (RL) is developing rapidly and has found its way into various fields including clinical medicine in which RL is employed to find an optimal treatment strategy. The key idea of RL is to optimize the treatment policy depending on the current state and previous treatment history, which is consistent with the idea behind dynamic programming (DP). DP is a prototype of RL and can be implemented when the system dynamics can be fully quantified.

METHODS

The present article aims to illustrate how to perform DP algorithm in a clinical scenario of Sepsis resuscitation. The state transition dynamics are constructed in the framework of Markov Decision Process. The state space is defined by mean arterial pressure (MAP) and lactate; the action space is comprised of fluid administration and vasopressor. The implementation of policy evaluation, policy improvement and iteration are explained with R code.

RESULTS

the DP algorithm was able to find the optimal treatment policy depending on the current states and previous conditions. The iteration process converged at finite steps. We defined several functions such as nextStep(), policyEval() and policy_iteration() to implement the DP algorithm.

CONCLUSIONS

This article illustrates how DP can be used to solve a clinical problem. We show that DP is a potential useful tool to tailor treatment strategy to patients with different conditions/states. Potential audience of the paper are those who are interested in using DP for solving clinical problems with dynamic changing states.

The cross-sectional and longitudinal associations of dietary patterns with knee symptoms and MRI detected structure in patients with knee osteoarthritis

OBJECTIVES

To examine the cross-sectional and longitudinal associations of dietary patterns with knee symptoms and structures in patients with knee osteoarthritis (OA).

METHODS

Participants with symptomatic knee OA were recruited from a randomised, placebo-controlled trial conducted in Tasmania (N = 259) and Victoria (N = 133). Diet was assessed by the Anti-Cancer Council of Victoria food frequency questionnaire. Factor analysis was used to identify dietary patterns. Knee symptoms were assessed using Western Ontario and McMaster Universities Arthritis Index (WOMAC) and structures using MRI. Multivariable linear regressions were used to examine associations.

RESULTS

Three dietary patterns ("high-fat", "healthy" and "mixed") were identified in whole sample. Participants with higher "healthy pattern" score had lower total WOMAC, pain, function and stiffness scores at baseline but the associations were not significant over 24 months. Three ("western", "vegetable and meat" and "mediterranean") and two ("processed" and "vegetable") patterns were identified in Tasmania and Victoria, respectively. Cross-sectionally, only "mediterranean pattern" and "vegetable pattern" scores were significantly and negatively associated with total WOMAC or function scores. Longitudinally, participants with higher "western pattern" had worsening function (β: 0.35, 95%CI: 0.03, 0.67) and total WOMAC (β: 0.40, 95%CI: 0.07, 0.72) scores; furthermore, "vegetable pattern" was associated with decreased WOMAC stiffness score (β: -0.47, 95%CI: -0.93, -0.02). In contrast, dietary patterns were largely not associated with structural changes.

CONCLUSION

Some healthy dietary patterns were associated with reduced joint symptoms but dietary patterns were not associated with joint structure in this sample with knee OA. Further studies are required to confirm these findings.

MicroRNA-26b-5p alleviates cerebral ischemia-reperfusion injury in rats via inhibiting the N-myc/PTEN axis by downregulating KLF10 expression

MicroRNAs plays important role in cerebral ischemia-reperfusion (CIR). However, the role of miR-26b-5p in CIR injury remains unclear. PC12 cells were treated with oxygen-glucose deprivation (OGD) for 0 h, 2 h, 4 h, 6 h, and then reoxygenated for 24 h to construct an in vitro I/R model. Then, miR-26b-5p mimic, small interfering RNA of KLF10 and KLF10 overexpression plasmid were transfected into cells respectively for mechanism study. Our results showed that miR-26b-5p was downregulated in OGD/R-induced PC12 cells. After overexpression of miR-26b-5p, cell proliferation ability was enhanced, apoptosis, ROS and inflammatory mediators were inhibited. Bioinformatics analysis indicated that miR-26b-5p was directly bound to the 3' UTR of KLF10, and downregulated the expression of KLF10. KLF10 was upregulated in OGD/R cells, and transfection with si-KLF10 promoted cell proliferation and reduced apoptosis, NO concentration and inflammatory factor secretion. Moreover, pcDNA-KLF10 reversed the inhibitory effects of miR-26b-5p mimic on apoptosis, NO content and inflammatory factor secretion, as well as the downregulation of N-myc and PTEN expression. Meanwhile, I/R rat models were constructed and divided into sham operation group (femoral artery isolation only), model group (middle cerebral artery occlusion model of rats was prepared by thread embolization), treatment group (200 µL of miR-26b-5p mimic was injected into the brain of model rats). We observed that the infarct size of brain tissue was reduced, KLF10 expression was downregulated, and apoptosis and inflammatory response were reduced. These results suggest that miR-26b-5p had protective effects on CIRI and it may be a potential treatment target.

SETD4 in the Proliferation, Migration, Angiogenesis, Myogenic Differentiation and Genomic Methylation of Bone Marrow Mesenchymal Stem Cells

Epigenetic modification is a crucial mechanism affecting the biological function of stem cells. SETD4 is a histone methyltransferase, and its biological role in bone marrow mesenchymal stem cells (BMSCs) is currently unknown. In this study, we employed CRISPR/Cas9 technology edited mouse model and found that SETD4 knockout significantly promoted the proliferation of BMSCs, impaired BMSCs migration and differentiation potentials of lineages of cardiacmyocyte and smooth muscle cell, and even the angiogenesis via paracrine of VEGF. Through Reduced Representation Bisulfite Sequencing (RRBS) method, we verified that the overall genomic methylation of BMSCs in the SETD4 knockout group only was decreased by 0.47 % compared with wild type. However, the changed genomic methylation covers a total of 96,331 differential methylated CpG sites and 8,692 differential methylation regions (DMRs), with part of them settled in promoter regions. Bioinformatic analysis revealed that differential CpG islands and DMRs in promoter impacted 270 GO functions and 34 KEGG signaling pathways, with some closely related to stem cell biology. Mechanismly, SETD4 knockout inhibited sets of monomethylases and dimethylases for histone lysine, along with significant changes in some factors including Nkx2.5, Gata4, Gli2, Grem2, E2f7, Map7, Nr2f2 and Shox2 that associated with stem cell biology. These results are the first to reveal that even though SETD4 changes the genome's overall methylation to a limited extent in BMSCs, it still affects the numerous cellular functions and signaling pathways, implying SETD4-altered genomic methylation serves a crucial molecular role in BMSCs' biological functions.

Repurposing antitussive benproperine phosphate against pancreatic cancer depends on autophagy arrest

Pancreatic cancer (PC) is one of the most common human malignancies worldwide and remains a major clinical challenge. Here, we found that benproperine phosphate (BPP), a cough suppressant, showed a significant anticancer effect on PC both in vitro and in vivo via the induction of autophagy‐mediated cell death. Mechanistic studies revealed that BPP triggered AMPK/mTOR‐mediated autophagy initiation and disturbed Ras‐related protein Rab‐11A (RAB11A)‐mediated autophagosome–lysosome fusion, resulting in excessive accumulation of autophagosomes. Inhibition of autophagy or overexpression of RAB11A partially reversed BPP‐induced growth inhibition in PC cells, suggesting that BPP might induce lethal autophagy arrest in PC cells. In conclusion, our results identify BPP as a potent antitumor agent for PC via the induction of autophagy arrest, therefore providing a new potential therapeutic strategy for the treatment of PC.

Tafolecimab, a novel potential long-acting PCSK9 monoclonal antibody: efficacy and safety in healthy and hypercholesterolemia subjects

Background

LDL cholesterol (LDL-C) is a well-established risk factor for cardiovascular disease. PCSK9 binds LDL receptors, targeting them for degradation. The dosing intervals for currently available PCSK9 monoclonal antibodies are once every 2 or 4 weeks. Tafolecimab, a novel recombinant human PCSK9 monoclonal antibody, was found to have higher affinity with PCSK9 and show longer LDL-C reduction compared to evolocumab in preclinical studies.

Purposes

The objectives for the SAD and MAD studies were to investigate the safety and efficacy of tafolecimab and explore the optimal dosing schedule.

Methods

The phase 1 study was a randomized, placebo-controlled, double-blind, single-ascending dose study (SAD) in Chinese healthy subjects, who were randomized 3:1 to tafolecimab and placebo (n=58). SAD subjects received tafolecimab subcutaneously at 25/75/150/300/450/600mg, or intravenously at 75/450mg, monitored up to day 84. The phase 2 study was a randomized, double-blind, placebo-controlled, repeated-dosing, multiple ascending dose (MAD) study in patients with hypercholesterolemia, who were randomized 4:1 to tafolecimab and placebo (n=60). MAD subjects received tafolecimab subcutaneously at 75/140mg every 2 weeks, 300/420mg every 4weeks, 450/600mg every 6 weeks up to day 84 or 98 with 3 months follow-up.

Results

In the SAD, the maximum mean reduction in LDL-C ranged from 52.2% to 72.1% and was achieved as early as 5 days (figure 1a). The duration of LDL-C reduction was tafolecimab dose dependent. In the MAD, the mean LDL-C concentrations were reduced by tafolecimab for each dose at 12 weeks relative to baseline (ranging from 54.30% to 72.26%; p&lt;0.001). Particularly, a 56.52% (−72.50%, −40.54%) reduction of LDL-C was observed in the cohort of 600mg Q6W. The effect sustained till week 14 (8 weeks after the last dose) where there was still a 43.46% (−60.96%, −25.96%) reduction from baseline (figure 1b). The mean reduction of Lp(a) at week 12 ranged from 24.04% to 50.59% relative to baseline. Tafolecimab reduced the other lipids when comparing with placebo. The pharmacokinetics/pharmadynamics (LDL-C) profiles of tafolecimab were well characterised and support the potential dosing interval of 6–8 weeks subcutaneously.

Both healthy and hypercholesterolemia subjects are generally tolerable to tafolecimab. Reported treatment-emergent adverse events (TEAEs) were: tafolecimab 23 (52.3%) vs. placebo 8 (57.1%); tafolecimab 34 (70.8%) vs. placebo 9 (75.0%) in the SAD and MAD respectively. There were no serious TEAEs or events leading to death or treatment discontinuation in both SAD and MAD.

Conclusions

Tafolecimab was well tolerated in both healthy and hypercholesterolemia in Chinese subjects, and improved lipid profile including LDL-C, Lp(a) and other lipids. The sustained effects on LDL-C suggests the potential of tafolecimab as a long-lasting PCSK9 inhibitor with dosing interval of 6–8 weeks or beyond.

Figure 1. LDL-C: Percent change from baseline

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Innovent Biologics (Suzhou), China

Resistance to FGFR1-targeted therapy leads to autophagy via TAK1/AMPK activation in gastric cancer

BACKGROUND

Fibroblast growth factor receptor 1 (FGFR1) is frequently dysregulated in various tumors. FGFR inhibitors have shown promising therapeutic value in several preclinical models. However, tumors resistant to FGFR inhibitors have emerged, compromising therapeutic outcomes by demonstrating markedly aggressive metastatic progression; however, the underlying signaling mechanism of resistance remains unknown.

METHODS

We established FGFR inhibitor-resistant cell models using two gastric cancer (GC) cell lines, MGC-803 and BGC-823. RNA-seq was performed to determine the continuous cellular transcriptome changes between parental and resistant cells. We explored the mechanism of resistance to FGFR inhibitor, using a subcutaneous tumor model and GC patient-derived tumor organotypic culture.

RESULTS

We observed that FGFR1 was highly expressed in GC and FGFR1 inhibitor-resistant cell lines, demonstrating elevated levels of autophagic activity. These resistant cells were characterized by epithelial-mesenchymal transition (EMT) required to facilitate metastatic outgrowth. In drug-resistant cells, the FGFR1 inhibitor regulated GC cell autophagy via AMPK/mTOR signal activation, which could be blocked using either pharmacological inhibitors or essential gene knockdown. Furthermore, TGF-β-activated kinase 1 (TAK1) amplification and metabolic restrictions led to AMPK pathway activation and autophagy. In vitro and in vivo results demonstrated that the FGFR inhibitor AZD4547 and TAK1 inhibitor NG25 synergistically inhibited proliferation and autophagy in AZD4547-resistant cell lines and patient-derived GC organotypic cultures.

CONCLUSIONS

We elucidated the molecular mechanisms underlying primary resistance to FGFR1 inhibitors in GC, and revealed that the inhibition of FGFR1 and TAK1 signaling could present a potential novel therapeutic strategy for FGFR1 inhibitor-resistant GC patients.

LncRNA MALAT1 inhibits osteogenic differentiation of mesenchymal stem cells in osteoporosis rats through MAPK signaling pathway

OBJECTIVE

The aim of this study was to explore whether long non-coding ribonucleic acid metastasis-associated lung adenocarcinoma transcript 1 (lncRNA MALAT1) could lead to osteoporosis (OP) by stimulating the activation of the mitogen-activated protein kinase (MAPK) signaling pathway.

MATERIALS AND METHODS

The OP model was first successfully established in rats. The expression of lncRNA MALAT1 in OP rats and normal rats was detected via quantitative Polymerase Chain Reaction (qPCR). Bone marrow mesenchymal stem cells (BMSCs) were cultured and transfected to establish the MALAT1 knockdown model. Subsequently, the apoptosis of mesenchymal stem cells in MALAT1 siRNA group and NC siRNA group was detected via flow cytometry. Meanwhile, the expressions of the MAPK signaling pathway proteins related to OP were detected via Western blotting. After alkaline phosphatase (ALP) staining in cells of both groups, early osteogenic differentiation of BMSCs was observed.

RESULTS

The results of qPCR showed that the expression of lncRNA MALAT1 in OP rats was significantly lower than that of normal rats. It was observed under a fluorescence microscope that there were a large number of siRNA particles in BMSCs. The expression of lncRNA MALAT1 in cells was detected via Real Time-fluorescence qPCR as well. The results indicated that siRNA transfection could effectively inhibit the expression of lncRNA MALAT1, indicating successful transfection. Flow cytometry revealed that no significant difference was observed in the apoptosis of BMSCs between the MALAT1 siRNA group and NC siRNA group. Besides, the results of Western blotting showed that the expression levels of the MAPK signaling pathway-related proteins extracellular signal-regulated kinase 1/2 (ERK1/2) and P38 in MALAT1 siRNA group were significantly higher than those of the NC siRNA group. This indicated that inhibiting the expression of lncRNA MALAT1 might promote the activation of the OP-related MAPK pathway. According to the results of ALP staining, the depth of staining in MALAT1 siRNA group was markedly declined when compared with the NC siRNA group. Quantification of ALP activity demonstrated that ALP activity in the MALAT1 siRNA group was markedly declined compared with the NC siRNA group. The above results suggested that suppressing the expression of lncRNA MALAT1 could reduce the ALP activity of BMSCs. Furthermore, lncRNA MALAT1 inhibited osteogenic differentiation of BMSCs.

CONCLUSIONS

LncRNA MALAT1 was lowly expressed in OP rats. Moreover, it inhibited osteogenic differentiation of BMSCs by enhancing the activation of the MAPK signaling pathway, thereby promoting OP progression.

Second harmonic generation microscopy using pixel reassignment

Second harmonic generation (SHG) microscopy is expected to be a powerful tool for observing the cellular-level functionality and morphology information of thick tissue owe to its unique imaging properties. However, the maximum attainable resolution obtainable by SHG microscopy is limited by the use of long-wavelength, near-infrared excitation. In this paper, we report the use of pixel reassignment to improve the spatial resolution of SHG microscopy. The SHG signal is imaged onto a position-sensitive camera, instead of a point detector typically used in conventional SHG microscope. The data processing is performed through pixel reassignment and subsequent deblurring operation. We present the basic principle and a rigorous theoretical model for SHG microscopy using pixel reassignment (SHG-PR). And for the first time, the optimal reassignment factor for SHG-PR is derived based on the coherent characteristics and the dependence of wavelength in SHG microscopy. To evaluate the spatial resolution improvement, images of nano-beads separated by different distances and of a microtubule array have been simulated. We gain about a 1.5-fold spatial resolution enhancement compared to conventional SHG microscopy. When a further deblurring operation is implemented, this method allows for a total spatial resolution enhancement of about 1.87. Additionally, we demonstrate the validity of SHG-PR for raw data with noise. LAY DESCRIPTION: Second harmonic generation (SHG) microscopy has emerged as a powerful imaging technique in clinical diagnostics and biological research. SHG microscopy is label-free and provides intrinsic optical sectioning for three-dimensional (3D) imaging. However, a near-infrared excitation wavelength results a restriction in the maximum attainable spatial resolution of SHG microscopy. In this paper, we present a simple resolution-enhanced SHG imaging method, SHG microscopy using pixel reassignment (SHG-PR). We demonstrate a rigorous theoretical model for SHG-PR and derive the optimal reassignment factor. The simulation result shows the clear improvement of the image resolution and contrast in the SHG-PR after deblurring operation. The FWHM value of single microtubule shows that SHG-PR enables a spatial resolution enhancement by a factor of 1.5, compared to conventional SHG microscopy. After a proper deblurring operation, this method allows for a total spatial resolution enhancement of about 1.87. The improvements of spatial resolution and contrast are still valid for raw data with noise. It is expected that this method can contribute towards new insights in unstained tissue morphology, interaction of cells, and diseases diagnosis.

[Progress of cohort studies in countries from Asia and Europe]

Objective: To share related knowledge and experiences with countries along the line, literature regarding current cohort studies was summarized. Distribution, establishment and development of cohort studies among large prospective general population were analyzed in 17 countries of Western Asia and the 16 countries of Central and Eastern Europe. Methods: Literature review was conducted to collect basic information on cohort studies, with descriptive study used to analyze the characteristics of these cohort studies. Results: There were 562 cohort studies with sample size as more than 1 000 stated in Western Asia and Central and Eastern Europe, including 468 (83.27%) carried out in the nation itself and 94 (16.73%) with international multicentered collaboration. According to the nature of cohort studies, 347 (61.74%) were etiologically based. As for the contents involved, 310 (55.16%) of them targeted on chronic/non-communicable diseases, 125 (22.24%) concentrated on maternal and child health. Among those on chronic/non-communicable diseases, 51 (16.45%) were on cancers and 83 (26.77%) on cardiovascular disease studies. There appeared 10 large prospective cohort studies targeting on general population, mainly ongoing in Iran and European countries, with a duration of 8-29 years, including 4 of them with sample size as more than 50 000. In terms of the contents, epidemiological investigation, physical examination and biological samples collection took the major parts. Few papers were published in 9 out of the 10 cohort studies at the early stage of those projects but the number of papers increased annually and stabilized to certain extent. Conclusions: The regional distribution of cohort studies carried out in countries from the Western Asia and Central and Eastern European areas appeared unbalanced. Contents of these designs would mainly involve etiological studies, with focus on non-communicable diseases as cancer, cardiovascular disease, diabetes, respiratory diseases, mental and psychological diseases, and maternal and infant health etc.. However, only few large prospective cohort studies would base on general population.