[Progress in methodological research on bridging the efficacy-effectiveness gap of clinical interventions(2): to improve the extrapolation of efficacy]

Objective: Randomized controlled trials (RCT) usually have strict implementation criteria. The included subjects' characteristics of the conditions for the intervention implementation are quite different from the actual clinical environment, resulting in discrepancies between the risk-benefit of interventions in actual clinical use and the risk-benefit shown in RCT. Therefore, some methods are needed to enhance the extrapolation of RCT results to evaluate the real effects of drugs in real people and clinical practice settings. Methods: Six databases (PubMed, Embase, Web of Science, CNKI, Wanfang Data, and VIP) were searched up to 31st December 2022 with detailed search strategies. A scoping review method was used to integrate and qualitatively describe the included literature inductively. Results: A total of 12 articles were included. Three methods in the included literature focused on: ①improving the design of traditional RCT to increase population representation; ②combining RCT Data with real-world data (RWD) for analysis;③calibrating RCT results according to real-world patient characteristics. Conclusions: Improving the design of RCT to enhance the population representation can improve the extrapolation of the results of RCT. Combining RCT data with RWD can give full play to the advantages of data from different sources; the results of the RCT were calibrated against real-world population characteristics so that the effects of interventions in real-world patient populations can be predicted.

[Progress in methodological research on bridging the efficacy-effectiveness gap of clinical interventions (1): to improve the validity of real-world evidence]

Objective: Differences between randomized controlled trial (RCT) results and real world study (RWS) results may not represent a true efficacy-effectiveness gap because efficacy-effectiveness gap estimates may be biased when RWS and RCT differ significantly in study design or when there is bias in RWS result estimation. Secondly, when there is an efficacy- effectiveness gap, it should not treat every patient the same way but assess the real-world factors influencing the intervention's effectiveness and identify the subgroup likely to achieve the desired effect. Methods: Six databases (PubMed, Embase, Web of Science, CNKI, Wanfang Data, and VIP) were searched up to 31st December 2022 with detailed search strategies. A scoping review method was used to integrate and qualitatively describe the included literature inductively. Results: Ten articles were included to discuss how to use the RCT research protocol as a template to develop the corresponding RWS research protocol. Moreover, based on correctly estimating the efficacy-effectiveness gap, evaluate the intervention effect in the patient subgroup to confirm the subgroup that can achieve the expected benefit-risk ratio to bridge the efficacy-effectiveness gap. Conclusion: Using real-world data to simulate key features of randomized controlled clinical trial study design can improve the authenticity and effectiveness of study results and bridge the efficacy-effectiveness gap.

Transfer learning enhanced graph neural network for aldehyde oxidase metabolism prediction and its experimental application

Aldehyde oxidase (AOX) is a molybdoenzyme that is primarily expressed in the liver and is involved in the metabolism of drugs and other xenobiotics. AOX-mediated metabolism can result in unexpected outcomes, such as the production of toxic metabolites and high metabolic clearance, which can lead to the clinical failure of novel therapeutic agents. Computational models can assist medicinal chemists in rapidly evaluating the AOX metabolic risk of compounds during the early phases of drug discovery and provide valuable clues for manipulating AOX-mediated metabolism liability. In this study, we developed a novel graph neural network called AOMP for predicting AOX-mediated metabolism. AOMP integrated the tasks of metabolic substrate/non-substrate classification and metabolic site prediction, while utilizing transfer learning from 13C nuclear magnetic resonance data to enhance its performance on both tasks. AOMP significantly outperformed the benchmark methods in both cross-validation and external testing. Using AOMP, we systematically assessed the AOX-mediated metabolism of common fragments in kinase inhibitors and successfully identified four new scaffolds with AOX metabolism liability, which were validated through in vitro experiments. Furthermore, for the convenience of the community, we established the first online service for AOX metabolism prediction based on AOMP, which is freely available at https://aomp.alphama.com.cn.

Identifying canonical and replicable multi-scale intrinsic connectivity networks in 100k+ resting-state fMRI datasets

Despite the known benefits of data-driven approaches, the lack of approaches for identifying functional neuroimaging patterns that capture both individual variations and inter-subject correspondence limits the clinical utility of rsfMRI and its application to single-subject analyses. Here, using rsfMRI data from over 100k individuals across private and public datasets, we identify replicable multi-spatial-scale canonical intrinsic connectivity network (ICN) templates via the use of multi-model-order independent component analysis (ICA). We also study the feasibility of estimating subject-specific ICNs via spatially constrained ICA. The results show that the subject-level ICN estimations vary as a function of the ICN itself, the data length, and the spatial resolution. In general, large-scale ICNs require less data to achieve specific levels of (within- and between-subject) spatial similarity with their templates. Importantly, increasing data length can reduce an ICN's subject-level specificity, suggesting longer scans may not always be desirable. We also find a positive linear relationship between data length and spatial smoothness (possibly due to averaging over intrinsic dynamics), suggesting studies examining optimized data length should consider spatial smoothness. Finally, consistency in spatial similarity between ICNs estimated using the full data and subsets across different data lengths suggests lower within-subject spatial similarity in shorter data is not wholly defined by lower reliability in ICN estimates, but may be an indication of meaningful brain dynamics which average out as data length increases.

Predicting Radiation Esophagitis using 18F-FAPI-04 PET/CT in Patients with LA-ESCC Treated with Concurrent Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

This prospective study examined whether 18F-FAPI-04 PET/CT can predict the development and severity of radiation esophagitis (RE) in patients with locally advanced esophageal squamous cell carcinoma (LA-ESCC) treated with concurrent chemoradiotherapy.

MATERIALS/METHODS

From June 2021 to March 2022, images were prospectively collected from LA-ESCC patients who underwent 18F-FAPI-04 PET/CT examinations before and during radiotherapy. The development of RE was evaluated weekly according to Radiation Therapy Oncology Group criterion. The target-to-background ratio in blood (TBRblood) was analyzed at each time point and correlated with the onset and severity of RE. Factors that predicted RE were identified by multivariate logistic analyses.

RESULTS

Thirty patients (median age, 66.5 years [interquartile range: 56¨C71 years]; 22 men) were evaluated. Significantly higher TBRblood (during radiotherapy, mean: 3.06 vs 7.11, P = 0.003) and change in TBRblood compared with pre-RT (ΔTBRblood, mean: 0.67 vs 4.81, P = 0.002) were observed in patients with RE than patients without RE. Those with grade 3 RE had a significantly higher TBRblood (during radiotherapy, mean: 4.55 vs 9.66, P = 0.003) and ΔTBRblood (mean: 2.16 vs 7.50, P = 0.003) compared with those with RE

CONCLUSION

The ΔTBRblood on 18F-FAPI-04 PET/CT may be effective at identifying patients at risk for the development of RE, especially grade 3 RE.

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Affiliation(s)

X Hu Department of Radiology, Shandong Cancer Hospital and Institute, Shandong First Medical University, Shandong Academy of Medical Sciences, Jinan, Shandong, China
C Han Department of Surgery II, Breast Cancer Center, Shandong Cancer Hospital and Institute, Jinan, Shandong, China
M Zhang 1.Department of Radiology, Shandong Cancer Hospital and Institute, Shandong First Medical University, Shandong Academy of Medical Sciences, Jinan, Shandong, China. 2.Cheeloo College of Medicine, Shandong University, Jinan, China
Z Mu Department of Pathology, Shandong Cancer Hospital and Institute, Shandong First Medical University, Shandong Academy of Medical Sciences, Jinan, Shandong, China
Z Fu Shandong Cancer Hospital and Institute, Jinan, China
J Ren Department of PET/CT Center, Shandong Cancer Hospital and Institute, Shandong First Medical University, Shandong Academy of Medical Sciences, Jinan, China
K Qiao Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
J Jia Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China 2. Department of Radiology, Shandong Cancer Hospital and Institute, Shandong First Medical University, Shandong Academy of Medical Sciences, Jinan, Shandong, China
J Yu Shandong Cancer Hospital, Shandong University, Jinan, Shandong, China
S Yuan Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
Y Wei Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China

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Versatile Biocatalytic C(sp3 )-H Oxyfunctionalization for the Site- Selective and Stereodivergent Synthesis of α- and β-Hydroxy Acids

C(sp3 )-H oxyfunctionalization, the insertion of an O-atom into C(sp3 )-H bonds, streamlines the synthesis of complex molecules from easily accessible precursors and represents one of the most challenging tasks in organic chemistry with regard to site and stereoselectivity. Biocatalytic C(sp3 )-H oxyfunctionalization has the potential to overcome limitations inherent to small-molecule-mediated approaches by delivering catalyst-controlled selectivity. Through enzyme repurposing and activity profiling of natural variants, we have developed a subfamily of α-ketoglutarate-dependent iron dioxygenases that catalyze the site- and stereodivergent oxyfunctionalization of secondary and tertiary C(sp3 )-H bonds, providing concise synthetic routes towards four types of 92 α- and β-hydroxy acids with high efficiency and selectivity. This method provides a biocatalytic approach for the production of valuable but synthetically challenging chiral hydroxy acid building blocks.

Spatial Dynamic Subspaces Encode Sex-Specific Schizophrenia Disruptions in Transient Network Overlap and its Links to Genetic Risk

Background

Recent advances in resting-state fMRI allow us to study spatial dynamics, the phenomenon of brain networks spatially evolving over time. However, most dynamic studies still use subject-specific, spatially-static nodes. As recent studies have demonstrated, incorporating time-resolved spatial properties is crucial for precise functional connectivity estimation and gaining unique insights into brain function. Nevertheless, estimating time-resolved networks poses challenges due to the low signal-to-noise ratio, limited information in short time segments, and uncertain identification of corresponding networks within and between subjects.

Methods

We adapt a reference-informed network estimation technique to capture time-resolved spatial networks and their dynamic spatial integration and segregation. We focus on time-resolved spatial functional network connectivity (spFNC), an estimate of network spatial coupling, to study sex-specific alterations in schizophrenia and their links to multi-factorial genomic data.

Results

Our findings are consistent with the dysconnectivity and neurodevelopment hypotheses and align with the cerebello-thalamo-cortical, triple-network, and frontoparietal dysconnectivity models, helping to unify them. The potential unification offers a new understanding of the underlying mechanisms. Notably, the posterior default mode/salience spFNC exhibits sex-specific schizophrenia alteration during the state with the highest global network integration and correlates with genetic risk for schizophrenia. This dysfunction is also reflected in high-dimensional (voxel-level) space in regions with weak functional connectivity to corresponding networks.

Conclusions

Our method can effectively capture spatially dynamic networks, detect nuanced SZ effects, and reveal the intricate relationship of dynamic information to genomic data. The results also underscore the potential of dynamic spatial dependence and weak connectivity in the clinical landscape.

MolFilterGAN: a progressively augmented generative adversarial network for triaging AI-designed molecules

Artificial intelligence (AI)-based molecular design methods, especially deep generative models for generating novel molecule structures, have gratified our imagination to explore unknown chemical space without relying on brute-force exploration. However, whether designed by AI or human experts, the molecules need to be accessibly synthesized and biologically evaluated, and the trial-and-error process remains a resources-intensive endeavor. Therefore, AI-based drug design methods face a major challenge of how to prioritize the molecular structures with potential for subsequent drug development. This study indicates that common filtering approaches based on traditional screening metrics fail to differentiate AI-designed molecules. To address this issue, we propose a novel molecular filtering method, MolFilterGAN, based on a progressively augmented generative adversarial network. Comparative analysis shows that MolFilterGAN outperforms conventional screening approaches based on drug-likeness or synthetic ability metrics. Retrospective analysis of AI-designed discoidin domain receptor 1 (DDR1) inhibitors shows that MolFilterGAN significantly increases the efficiency of molecular triaging. Further evaluation of MolFilterGAN on eight external ligand sets suggests that MolFilterGAN is useful in triaging or enriching bioactive compounds across a wide range of target types. These results highlighted the importance of MolFilterGAN in evaluating molecules integrally and further accelerating molecular discovery especially combined with advanced AI generative models.

Asymmetric C1 Extension of Aldehydes through Biocatalytic Cascades for Stereodivergent Synthesis of Mandelic Acids

The development of mild, efficient, and enantioselective methods for preparing chiral building blocks from simple, renewable carbon units has been a long-term goal of the sustainable chemical industry. Mandelate derivatives are valuable pharmaceutical intermediates and chiral resolving agents, but their manufacture relies heavily on highly toxic cyanide. Herein, we report (S)-4-hydroxymandelate synthase (HmaS)-centered biocatalytic cascades for the synthesis of mandelates from benzaldehydes and glycine. We show that HmaS can be engineered to perform (R)-selective hydroxylation by single-point mutation, empowering the stereo-divergent synthesis of both (S)- and (R)-mandelate derivatives. We demonstrated that these biocatalytic cascades enabled the production of various mandelate derivatives with great atom economy, excellent yields (up to 98%) and enantiomeric excess (up to >99%). This methodology offers an effective cyanide-free technology for greener and sustainable production of mandelate derivatives.

Search for the Majorana Nature of Neutrinos in the Inverted Mass Ordering Region with KamLAND-Zen

The KamLAND-Zen experiment has provided stringent constraints on the neutrinoless double-beta (0νββ) decay half-life in ^{136}Xe using a xenon-loaded liquid scintillator. We report an improved search using an upgraded detector with almost double the amount of xenon and an ultralow radioactivity container, corresponding to an exposure of 970 kg yr of ^{136}Xe. These new data provide valuable insight into backgrounds, especially from cosmic muon spallation of xenon, and have required the use of novel background rejection techniques. We obtain a lower limit for the 0νββ decay half-life of T_{1/2}^{0ν}>2.3×10^{26}  yr at 90% C.L., corresponding to upper limits on the effective Majorana neutrino mass of 36-156 meV using commonly adopted nuclear matrix element calculations.

Thrombectomy Using the EmboTrap Clot-Retrieving Device for the Treatment of Acute Ischemic Stroke: A Glimpse of Clinical Evidence

BACKGROUND

The EmboTrap Recanalization Device is a novel stent retriever for thrombectomy in the setting of acute ischemic stroke due to large-vessel occlusion.

PURPOSE

Our aim was to summarize the safety and efficacy of the EmboTrap Recanalization Device in acute ischemic stroke-large-vessel occlusion through a systematic review and meta-analysis.

DATA SOURCES

Medline, EMBASE, the Cochrane Library, Web of Science, and Google Scholar were searched up to April 2022.

STUDY SELECTION

Nine observational studies using the EmboTrap Recanalization Device were selected.

DATA ANALYSIS

We adapted effect size with 95% CIs for dichotomous data. P value <.05 was statistically significant.

DATA SYNTHESIS

The estimated rate of successful recanalization (modified TICI 2b-3) was 90% (95% CI, 86%-95%; I ² = 82.4%); 90-day favorable outcome (mRS 0-2), 53% (95% CI, 42%-63%; I ² = 88.6%); modified first-pass effect, 43% (95% CI, 35%-51%; I ² = 63.7%); and first-pass effect, 36% (95% CI, 29%-46%; I ² = 10.7%). The rate of any intracerebral hemorrhage was 19% (95% CI, 16%-22%; I ² = 0.0%); symptomatic intracerebral hemorrhage, 5% (95% CI, 1%-8%; I ² = 84.6%); and 90-day mortality, 14% (95% CI, 9%-19%; I ² = 79.3%). Subgroup analysis showed higher rates of complete recanalization for EmboTrap II than for the EmboTrap System.

LIMITATIONS

The included studies are single-arm without direct comparison with other stent retrievers. Some of the studies recruited had a small sample size and were limited by the retrospective study design. In addition, the uncertain heterogeneity among studies was high.

CONCLUSIONS

The EmboTrap Recanalization Device is safe and efficient in treating acute ischemic stroke due to large-vessel occlusion.

[Real-world evidence and randomized controlled trials: the initiation, implementation, progress interpretation and revelation of RCT DUPLICATE (part 1)]

In recent years, researchers, pharmaceutical companies, and political makers gradually using more real-world data (RWD) to produce real-world evidence (RWE) for policy-making. A research team of Harvard University launched the RCT DUPLICATE project in 2018, aiming to replicate 30 randomized controlled trials using the medical claims database in order to explore methods for quantifying the efficacy-effectiveness gap and explain its potential sources, to enhance the credibility of the RWE. This paper reviews the background of RCT DUPLICATE Initiative, highlights the research purposes, research design and implementation process of the RCT DUPLICATE Initiative, to help domestic scholars better understand the scope and application value of RWE.

[Real-world evidence and randomized controlled trials: the initiation, implementation, progress interpretation and revelation of RCT DUPLICATE (part 2)]

With the promotion and application of big medical data, non-interventional real-world evidence (RWE) has been used by regulators to assess the effectiveness of medical products. This paper briefly introduces the latest progress and research results of the RCT DUPLICATE Initiative launched by the research team of Harvard University in 2018 and summarizes relevant research experience based on the characteristics of China's medical service to provide inspiration and reference for domestic scholars to conduct related RWE research in the future.

[Sorafenib regulates vascular endothelial growth factor by runt-related transcription factor-3 to inhibit angiogenesis in hepatocellular carcinoma]

Objective: To investigate the molecular mechanism of sorafenib against hepatocellular carcinoma. Methods: Sorafenib efficacy was screened and verified by the hepatocellular carcinoma patient-derived tumor xenograft (PDX) model. Veterinary B-mode ultrasonography and in vivo confocal laser scanning microscopy were used to observe PDX angiogenesis. Immunohistochemistry was used to observe the expression of proliferation and angiogenesis-related proteins in PDX tissue. Real-time quantitative PCR technology was used to observe the RUNX3 gene in PDX tissues. SPSS 17.0 statistical software was used for statistical analysis. Results: Four cases of PDX were used to screen the efficacy of sorafenib. PDX1 had a significant response to sorafenib, with an inhibition rate of 68.07%. Compared with the control group, sorafenib had significantly inhibited PDX1 relative tumor volume (5.76±2.14 vs. 11.71±2.87, P<0.05). Cell division index (39.50±7.72 vs. 67.10±9.14, P<0.05) and Ki67 expression (288.6±43.40 vs. 531.70±55.60, P<0.05) were significantly decreased. Veterinary B-mode ultrasonography showed evident blood flow signals in PDX1 tumors. In vivo confocal laser scanning microscopy results showed that sorafenib had significantly reduced the total vessel length (1573.00±236.21 vs. 2675.03±162.00, P<0.05) and area (11 145.33±1931.97 vs. 20 105.37±885.93, P<0.05)) of PDX1 tumors. Immunohistochemical results showed that sorafenib had significantly down-regulated the protein expressions of CD34 (27.55±3.76 vs. 45.47±5.57, P<0.05), VEGF (16.33±2.86 vs. 22.77±3.20, P<0.05) and MVD (38.75±6.01 vs. 55.50±8.61, P<0.05). Real-time PCR results showed that sorafenib had significantly up-regulated RUNX3 gene expression (2.14±0.71 vs. 1.00±0.36, P<0.05). However, there was a negative correlation between the expression of RUNX3 gene and the ratio of VEGF-positive cells in sorafenib group (R²=0.509 7). Conclusion: Sorafenib may inhibit the PDX angiogenesis and the growth of hepatocellular carcinoma by regulating the RUNX3-VEGF pathway.

ASSOCIATION BETWEEN THE CTLA-4 EXON 1+49A/G POLYMORPHISM AND THE RELAPSE OF GRAVE'S DISEASE AFTER ATD WITHDRAWAL: A META-ANALYSIS

Background

The cytotoxic T lymphocyte-associated molecules-4 (CTLA-4) is related to the relapse of Graves' disease (GD) after anti-thyroid drugs (ATDs) withdrawal. We performed a meta-analysis to generate large-scale evidence on whether the CTLA-4 exon 1+49A/G polymorphism can predict the relapse of GD after ATDs withdrawal.

Methods and Results

The PubMed, EMBASE,the Cochrane Library and reference lists of relevant studies were searched to identify eligible studies from inception to Jan, 2021. Ten eligible studies consisting of 1450 GD patients with a total of 848 relapsed patients were included in the meta-analysis.In Caucasians patients, the CTLA-4 exon 1+49A/G polymorphism significantly elevated the relapse risk of GD in additive (OR = 2.07, 95% CI: 1.18-3.62, P=0.011), dominant (OR = 2.52, 95% CI: 1.17-5.41, P=0.02), homozygote model(OR = 3.264, 95% CI: 1.25-8.52, P=0.016), except recessive (OR = 2.18, 95% CI = 0.98-4.86, P = 0.062) and heterozygote model (OR = 2.141, 95% CI = 0.958-4.786, P = 0.064). In Asian subgroup, none of these genotypes show any associations with the relapse of GD after ATDs withdrawal.

Conclusion

This meta-analysis suggests that the CTLA-4 exon1 +49A/G polymorphism is associated with the relapse risk of GD after ATDs withdrawal in Caucasians, not Asians. Compared with the AA genotype, Caucasian patients with GG genotype have 3.264 times risk of relapse. A more aggressive treatment such as radioactive iodine or thyroidectomy, or longer periods treatment of ATDs should be recommended in Caucasian patients with the GG genotype.

LB0005 ORELABRUTINIB, AN IRREVERSIBLE INHIBITOR OF BRUTON’S TYROSINE KINASE (BTK), FOR THE TREATMENT OF SYSTEMIC LUPUS ERYTHEMATOSUS (SLE): RESULTS OF A RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED, PHASE IB/IIA DOSE-FINDING STUDY

Background

Orelabrutinib is an oral, highly-selective, irreversible inhibitor of Bruton’s tyrosine kinase (BTK). Orelabrutinib has been approved for the treatment of B cell malignancies in China. Two distinct lupus animal models showed significant efficacy of orelabrutinib in reducing disease activity, which supported the clinical development of orelabrutinib in Systemic Lupus Erythematosus (SLE).

Objectives

This phase Ib/IIa, randomized, double-blind, placebo-controlled, dose-finding study aimed to evaluate the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), preliminary efficacy and biomarkers of orelabrutinib in patients with mild to moderate SLE who received standard of care (SoC) therapy.

Methods

Patients diagnosed with SLE by the ACR classification criteria for ≥ 6 months, who had a SLEDAI-2K score ≥5 at screening, and were autoantibody-positive, were randomized 1:1:1:1 to receive oral orelabrutinib at 50mg, 80mg, 100mg or placebo once daily for 12 weeks, respectively.

Results

This study randomized 60 patients with 55 patients who completed 12-week treatment. Age at baseline was 33.7±9.8 years and 96.7% were female. Baseline disease characteristics were generally balanced across treatment groups. Adverse events (AEs) were reported in 80%, 93.3% and 100% of orelabrutinib treated patients at doses of 50mg, 80mg and 100mg QD respectively versus 85.5% in placebo group. AEs were mostly mild or moderate. Treatment-related SAEs were reported in 3 patients treated with orelabrutinib, only 1 of which was grade 3. No deaths were reported. The plasma exposure of orelabrutinib (AUC and Cmax) was proportionally increased with doses. Nearly complete BTK occupancy was achieved at all dose levels, and the occupancy lasted for 24 hours without any decrease compared to that at 4 hour post-dosing. In all evaluable patients, the SLE Response Index (SRI)-4 response rates at week 12 were 50.0%, 61.5% and 64.3% in patients treated with orelabrutinib at 50mg (n=14), 80mg (n=13) and 100mg (n=14) respectively, compared with 35.7% in patients treated with placebo (n=14), which indicated the trend of dose-dependent improvement. Among the subgroup of patients with SLEDAI-2K≥8 at screening, SRI-4 response occurred in 70%, 70% and 66.7% of patients treated with orelabrutinib at 50mg (n=10), 80mg (n=10) and 100mg (n=9), respectively, compared with 30% who received placebo (n=10). Trends of reduced proteinuria, anti-dsDNA and IgG, total B cells and increased complements C4 were also observed following orelabrutinib treatment.

Conclusion

Orelabrutinib was generally safe and well tolerated in patients with SLE. Preliminary results also suggested encouraging efficacy which supports further development of orelabrutinib in larger and longer trials for SLE.

Table 1.

Efficacy results at week 12.

All Evaluable PatientsPlaceboOrelabrutinibOrelabrutinibOrelabrutinib50 mg80 mg100 mgN=5514141314SRI-4 response, n (%)5 (35.7%)7 (50.0%)8 (61.5%)9 (64.3%)Treatment difference vs. PBO (%)14.3%25.8%28.6%SLEDAI-2K≥8, N=391010109SRI-4 response, n (%)3 (30.0%)7 (70.0%)7 (70.0%)6 (66.7%)Treatment difference vs. PBO (%)40.0%40.0%36.7%

Note: All evaluable patients at week 12 efficacy data were included in the efficacy analysis.

Figure 1.

SRI-4 response rates at week 12.

Disclosure of Interests

Ru Li: None declared, Xiaoxia Zhu: None declared, Shengyun Liu: None declared, Xiao Zhang: None declared, Changhao Xie: None declared, Zili Fu: None declared, Anbin Huang: None declared, Lingyun Sun: None declared, Dongzhou Liu: None declared, Jinxia Zhao: None declared, Lin Wu: None declared, Zhoushuai Qin Employee of: InnoCare Pharma Limited., Sichen Li Employee of: InnoCare pharma Limited., Yaorong Liu Employee of: InnoCare pharma Limited., Zhanguo Li: None declared

Moving beyond the 'CAP' of the Iceberg: Intrinsic connectivity networks in fMRI are continuously engaging and overlapping

Resting-state functional magnetic resonance imaging is currently the mainstay of functional neuroimaging and has allowed researchers to identify intrinsic connectivity networks (aka functional networks) at different spatial scales. However, little is known about the temporal profiles of these networks and whether it is best to model them as continuous phenomena in both space and time or, rather, as a set of temporally discrete events. Both categories have been supported by series of studies with promising findings. However, a critical question is whether focusing only on time points presumed to contain isolated neural events and disregarding the rest of the data is missing important information, potentially leading to misleading conclusions. In this work, we argue that brain networks identified within the spontaneous blood oxygenation level-dependent (BOLD) signal are not limited to temporally sparse burst moments and that these event present time points (EPTs) contain valuable but incomplete information about the underlying functional patterns. We focus on the default mode and show evidence that is consistent with its continuous presence in the BOLD signal, including during the event absent time points (EATs), i.e., time points that exhibit minimum activity and are the least likely to contain an event. Moreover, our findings suggest that EPTs may not contain all the available information about their corresponding networks. We observe distinct default mode connectivity patterns obtained from all time points (AllTPs), EPTs, and EATs. We show evidence of robust relationships with schizophrenia symptoms that are both common and unique to each of the sets of time points (AllTPs, EPTs, EATs), likely related to transient patterns of connectivity. Together, these findings indicate the importance of leveraging the full temporal data in functional studies, including those using event-detection approaches.

[Mechanical circulatory support combined with immunomodulation treatment for patients with fulminant myocarditis: a single-center real-world study]

Objective: To investigate the relationship between the mechanical circulatory support (MCS) combined with immunomodulation and the prognosis of patients with fulminant myocarditis. Methods: This is a retrospective study. A total of 88 patients with fulminant myocarditis admitted to Dongguan Kanghua hospital from Aug. 2008 to Dec. 2020 were included. Medical histories, results of laboratory tests, treatment regimens and clinical outcomes of these patients during their hospitalization were collected from the medical record system. According to the treatment methods, the patients were divided into MCS+immunomodulation group (38 cases), MCS group (20 cases) and traditional treatment group (30 cases). Patients in the MCS+immunomodulation group received intra-aortic balloon pump (IABP) or IABP combined with extracorporeal membrane oxygenation (ECMO) and immunoglobulin or glucocorticoid. Patients in the MCS group only received mechanical circulatory support. Patients in the traditional treatment group received neither mechanical circulatory support nor immunomodulatory therapy, and only used vasoactive drugs and cardiotonic drugs. The in-hospital mortality and length of stay were compared among the three groups. Results: A total of 88 patients with fulminant myocarditis aged (35.0±10.8) years were included, and there were 46 males (52.3%). The mortality of MCS+immunomodulation group (7.9% (3/38) vs. 56.7% (17/30), P=0.001 2) and MCS group (30.0% (6/20) vs. 56.7% (17/30), P=0.002 8) were lower than that of traditional treatment group. Compared with the MCS group, the in-hospital mortality in the MCS+immunomodulation group was lower (P=0.005 4). The most common cause of death was multiple organ dysfunction syndrome (MODS). The constituent ratios of death in MCS+immunomodulation group, MCS group and traditional treatment group were 3/3, 4/6 and 12/17, respectively. The incidence of MODS in the MCS group (20% (4/20)) and the traditional treatment group (40% (12/30)) was significantly higher than that in the MCS+immunomodulation group (7.9% (3/38)) (both P<0.01). In discharged patients, the hospitalization time of MCS+immunomodulation group was shorter than that of traditional treatment group ((13.4±5.5)d vs. (18.5±7.4)d, P<0.05) and MCS group ((13.4±5.5)d vs. (16.9±8.5)d, P<0.05). Conclusion: MCS combined with immunomodulatory therapy is associated with lower in-hospital mortality and shorter hospital stay in patients with fulminant myocarditis.

An inductive graph neural network model for compound-protein interaction prediction based on a homogeneous graph

Identifying the potential compound–protein interactions (CPIs) plays an essential role in drug development. The computational approaches for CPI prediction can reduce time and costs of experimental methods and have benefited from the continuously improved graph representation learning. However, most of the network-based methods use heterogeneous graphs, which is challenging due to their complex structures and heterogeneous attributes. Therefore, in this work, we transformed the compound–protein heterogeneous graph to a homogeneous graph by integrating the ligand-based protein representations and overall similarity associations. We then proposed an Inductive Graph AggrEgator-based framework, named CPI-IGAE, for CPI prediction. CPI-IGAE learns the low-dimensional representations of compounds and proteins from the homogeneous graph in an end-to-end manner. The results show that CPI-IGAE performs better than some state-of-the-art methods. Further ablation study and visualization of embeddings reveal the advantages of the model architecture and its role in feature extraction, and some of the top ranked CPIs by CPI-IGAE have been validated by a review of recent literature. The data and source codes are available at https://github.com/wanxiaozhe/CPI-IGAE.

Effect of pathological complete response after neoadjuvant chemoradiotherapy on postoperative complications of rectal cancer: a systematic review and meta-analysis

BACKGROUND

Standard total mesorectal resection has become an important treatment option for locally advanced or high-risk rectal cancer after neoadjuvant chemo-radiotherapy. 15-27% of patients can achieve pathological complete response (PCR) after neoadjuvant chemo-radiotherapy (nCRT). However, the relationship between PCR and postoperative complications remains an important unsolved problem. The objective of this study was to determine whether PCR was associated with the rate of postoperative complications.

METHODS

This meta-analysis was implemented following the recommendations from Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We searched electronic literature by PubMed, EMBASE, and Google Scholar. Major outcomes of interest included anastomotic leakage, surgical-site infection, reoperation, and any postoperative complications. Other outcomes comprised postoperative hemorrhage, ileus, and mortality.

RESULTS

Eleven thousand two hundred ninety patients in 9 studies were included in the meta-analysis. The pooled analysis revealed that patients with PCR did not have a higher risk of anastomotic leakage (OR = 1.22, 95% CI 0.92-1.62, p = 0.17), reoperation (OR = 1.13, 95% CI 0.93-1.37, p = 0.22), and any postoperative complications (OR = 1.02, 95% CI 0.91-1.15, p = 0.72) than patients with non-PCR. However, the meta-analysis showed that the PCR group was superior to the non-PCR group in terms of surgical-site infection (9.38% vs. 12.44%OR = 0.68, 95% CI 0.47-0.98; p = 0.04).

CONCLUSION

PCR might not be related to the occurrence of postoperative complications in rectal cancer patients following nCRT. In addition, PCR might be associated with a lower risk of surgical-site infection.

Occupational burnout among clinical research associates in China

BACKGROUND

Clinical research associates (CRAs) play an important role in pharmaceutical research and development. Despite growing concern about occupational burnout among CRAs in China, little is known about this topic.

AIMS

We evaluated the factors associated with occupational burnout among CRAs in China and assessed the extent and nature of this syndrome in order to develop effective countermeasures.

METHODS

In October 2020, we collected data from a convenience sample of 438 CRAs from 26 major cities across China using a custom-designed questionnaire. We evaluated their psychopathological status and degree of occupational burnout based on the Maslach Burnout Inventory. Factors associated with burnout were identified using the Wilcoxon rank test, Kruskal-Wallis test, Spearman's rank correlation and multivariable ordinal logistic regression.

RESULTS

Of the 438 CRAs analyzed, 82% showed signs of occupational burnout, with a large proportion experiencing moderate burnout (50%). Burnout in Chinese CRAs manifested as emotional exhaustion (77%), depersonalization (66%) and low sense of accomplishment (15%). The severity of burnout was significantly affected by mode of working (odds ratio [OR] 1.56, 95% confidence interval [CI] 1.04-2.34), average number of working hours per week (OR 1.68, 95% CI 1.14-2.46), support provided by the hospital (OR 3.13, 95% CI 1.40-6.99) and likelihood of receiving a promotion (OR 4.05, 95% CI 1.34-12.22) (all P < 0.05).

CONCLUSIONS

The incidence of occupational burnout among CRAs in China is high. Companies and hospitals must take effective measures to establish support systems for CRAs in order to alleviate this situation and thereby ensure the quality of clinical trials.

Multi-instance learning of graph neural networks for aqueous pKa prediction

MOTIVATION

The acid dissociation constant (pKa) is a critical parameter to reflect the ionization ability of chemical compounds and is widely applied in a variety of industries. However, the experimental determination of pKa is intricate and time-consuming, especially for the exact determination of micro-pKa information at the atomic level. Hence, a fast and accurate prediction of pKa values of chemical compounds is of broad interest.

RESULTS

Here, we compiled a large-scale pKa dataset containing 16 595 compounds with 17 489 pKa values. Based on this dataset, a novel pKa prediction model, named Graph-pKa, was established using graph neural networks. Graph-pKa performed well on the prediction of macro-pKa values, with a mean absolute error around 0.55 and a coefficient of determination around 0.92 on the test dataset. Furthermore, combining multi-instance learning, Graph-pKa was also able to automatically deconvolute the predicted macro-pKa into discrete micro-pKa values.

AVAILABILITY AND IMPLEMENTATION

The Graph-pKa model is now freely accessible via a web-based interface (https://pka.simm.ac.cn/).

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Changed expression of microRNAs may predict postoperative atrial fibrillation in patients with cardiac surgery

OBJECTIVE

Changes of microRNAs (miRNAs) may contribute to the pathogenesis and progression of postoperative atrial fibrillation (POAF) in patients undergoing cardiac valve surgery. This study aimed to measure the expression levels of miRNAs in peripheral blood, as well as their target mRNAs, in POAF patients and normal controls (non-POAF), and to evaluate the potential of miRNAs as promising biomarkers to predict POAF.

PATIENTS AND METHODS

The expression of miRNAs in peripheral blood, including miR-27b, miR-133a, miR-328, miR-499 and their target mRNAs, was analyzed in 109 POAF patients and 96 non-POAF patients via quantitative real-time polymerase chain reaction (RT-PCR). We compared differences between the two groups and also analyzed the treat reaction to amiodarone.

RESULTS

All miRNAs in POAF patients were significantly highly expressed. Compared to non-POAF, the expression of miR-27b, miR-133a, miR-328, miR-499 increased in both groups of POAF patients, and miR-499 was the only upregulated miRNAs in the amiodarone - group versus amiodarone + group and non-POAF. Among the upregulated miRNAs, miR-499 expression significantly changed in amiodarone + and amiodarone - patients (p = 0.005). The ROC curve analysis revealed that miR-499 might be a potential therapeutic response biomarker. The miRNA-mRNA interactions revealed 10 mRNAs regulated by miR-27b, miR-133a, and miR- 499.

CONCLUSIONS

We found an expression on miR-133a, miR-27b, miR-328, and miR-499 was significantly different between these groups, with a high expression being observed in POAF patients compared to non-POAF patients. Further, the present results showed that miR-499 was significantly upregulated in amiodarone - patients, compared to non-POAF, and amiodarone + patients. This finding indicates that miR-499 may be a potential biomarker for predicting the occurrence of POAF after cardiac valve surgery and treat the reaction to amiodarone.

SK2 channel deletion reduces susceptibility to bupivacaine-induced cardiotoxicity in mouse

Bupivacaine is frequently used for regional anesthesia and postoperative analgesia. However, an inadvertent intravenous injection can cause severe cardiotoxicity, manifesting as arrhythmia, hypotension, and even cardiac asystole. The mechanism of bupivacaine-mediated cardiotoxicity remains unclear. SK2 knockout mice (SK) and wild-type mice (WT) were divided into four groups, with 12 mice per group. We determined the difference in bupivacaine cardiotoxicity between SK2 knockout and WT mice by measuring the time to the first arrhythmia (T_arrhythmia) and the time to asystole (T_asystole). Secondary indicators of cardiotoxicity were the time from the beginning of bupivacaine infusion to 20% prolongation of the QT interval (T_QT) and the time to 20% widening of the QRS complex (T_QRS). T_arrhythmia and T_asystole were significantly longer in the SK-bupi group than in the WT-bupi group (both P < 0.05). T_QT and T_QRS were longer in the SK-bupi group than in the WT-bupi group (all P < 0.05). The time to 25%, 50%, and 75% reduction in HR in the SK-bupi group was significantly longer than in the WT-bupi group (all P < 0.05). Knocking out the SK2 channel can reduce bupivacaine-induced cardiotoxicity in the mouse.

Apelin-13 protects the lungs from ischemia-reperfusion injury by attenuating inflammatory and oxidative stress

Apelin has been reported to regulate mitochondrial function in myocardial ischemia-reperfusion injury and cerebral ischemia-reperfusion injury. However, the role of apelin-13 in lung ischemia-reperfusion injury (LIRI) remains unclear. This study established an experimental rat model to evaluate the underlying mechanisms of apelin-13 on LIRI. Twenty-four rats were randomly divided to sham operation group (group SM), ischemia/reperfusion group (group IR), and apelin-13 treatment group (group APL). The effects of apelin-13 on LIRI were determined histologically using H&E staining, while the wet/dry weight ratio was used to assess lung edema caused by LIRI. Inflammatory cytokines were also detected in Bronchoalveolar lavage (BAL) fluid by ELISA. The protein expression of UCP2 and the morphological changes of mitochondria were determined by western blotting and electromicroscopy, respectively. The results demonstrated the structural damage of lung tissues and lung edema in group IR. An increased level of inflammatory cytokines including IL-1β, IL-6 and TNF-α was observed in rats with LIRI using ELISA. After that, oxidative stress and morphological damage of mitochondria were also shown in group IR. Yet, the application of apelin-13 reversed all these deleterious effects in group APL. The protective effects of apelin-13 were indicated by decreased reactive oxygen species (ROS) and elevated UCP2 expression levels in rats. In conclusion, this study revealed that apelin-13 had protective effects against LIRI via attenuating lung edema, the production of inflammatory cytokines, oxidative stress and mitochondrial dysfunction.

Cytoplasmic DNA sensing by KU complex in aged CD4+ T cell potentiates T cell activation and aging-related autoimmune inflammation

Aging is associated with DNA accumulation and increased homeostatic proliferation of circulating T cells. Although these attributes are associated with aging-related autoimmunity, their direct contributions remain unclear. Conventionally, KU complex, the regulatory subunit of DNA-dependent protein kinase (DNA-PK), together with the catalytic subunit of DNA-PK (DNA-PKcs), mediates DNA damage repair in the nucleus. Here, we found KU complex abundantly expressed in the cytoplasm, where it recognized accumulated cytoplasmic DNA in aged human and mouse CD4⁺ T cells. This process enhanced T cell activation and pathology of experimental autoimmune encephalomyelitis (EAE) in aged mice. Mechanistically, KU-mediated DNA sensing facilitated DNA-PKcs recruitment and phosphorylation of the kinase ZAK. This activated AKT and mTOR pathways, promoting CD4⁺ T cell proliferation and activation. We developed a specific ZAK inhibitor, which dampened EAE pathology in aged mice. Overall, these findings demonstrate a KU-mediated cytoplasmic DNA-sensing pathway in CD4⁺ T cells that potentiates aging-related autoimmunity.

DrugSpaceX: a large screenable and synthetically tractable database extending drug space

One of the most prominent topics in drug discovery is efficient exploration of the vast drug-like chemical space to find synthesizable and novel chemical structures with desired biological properties. To address this challenge, we created the DrugSpaceX (https://drugspacex.simm.ac.cn/) database based on expert-defined transformations of approved drug molecules. The current version of DrugSpaceX contains >100 million transformed chemical products for virtual screening, with outstanding characteristics in terms of structural novelty, diversity and large three-dimensional chemical space coverage. To illustrate its practical application in drug discovery, we used a case study of discoidin domain receptor 1 (DDR1), a kinase target implicated in fibrosis and other diseases, to show DrugSpaceX performing a quick search of initial hit compounds. Additionally, for ligand identification and optimization purposes, DrugSpaceX also provides several subsets for download, including a 10% diversity subset, an extended drug-like subset, a drug-like subset, a lead-like subset, and a fragment-like subset. In addition to chemical properties and transformation instructions, DrugSpaceX can locate the position of transformation, which will enable medicinal chemists to easily integrate strategy planning and protection design.

Family History of Crohn’s Disease (CD) May Be a Risk Factor for Developing de novo CD following Ileal Pouch Anal Anastomosis (IPAA) for Ulcerative Colitis (UC)

Introduction/Objective

A subset of patients with an established diagnosis of UC develops signs of CD (de novo CD) following IPAA. While the etiology and risk factors of de novo CD remain largely unknown, preliminary studies have shown controversial results regarding family history of inflammatory bowel disease (IBD) and smoking history.

Methods

Patients that underwent IPAA for UC, with at least 1 year of follow-up, were identified (n=161; 1996 to 2018). We retrospectively reviewed the electronic medical records. Patients that were diagnosed with de novo CD during the follow-up period were further identified. Smoking history and family history of IBD were evaluated. Chi square test was performed to compare the frequencies. Odds ratio (OR) and 95% confidence intervals (CIs) were estimated by logistic regression model. P&lt;0.05 was considered statistically significant.

Results

29 de novo CD were identified. At the time of proctocolectomy, the family history of IBD and smoking history was documented in 152 UC patients including 27 that subsequently developed de novo CD. 23 of 152 had a family history of IBD (12 UC, 9 CD and 2 IBD, NOS). 19/129 (14.7%) UC patients without a family history of any type of IBD, 4/9 (44.4%) with a family history of CD, and 4/12 (33.3%) with a family history of UC developed de novo CD. Patients with a family history of CD were more likely to develop de novo CD post IPAA than those without a family history of any type of IBD (OR 4.63, 95% CI 1.14-18.82, p=0.03). Family history of UC did not correlate with development of de novo CD (OR 2.90; 95% CI 0.79-10.57, p=0.108). At the time of proctocoletomy, 11 were current smokers, 25 were former smokers, and 116 never smoked. In de novo CD group, there were 4/27 (14.8 %) former smokers and 23/27 (85.2 %) never smokers. No de novo CD patient was current smoker. In the UC group that remained as UC following IPAA, 11/125 (8.8%) were current smokers, 21/125 (16.8 %) former smokers, and 93/125 (74.4 %) were never smokers. Current smoking status was not associated with development of de novo CD (p = 0.214).

Conclusion

Family history of CD may be a risk factor for developing de novo CD following IPAA for UC. Current smoking status was not associated with development of de novo CD following IPAA for UC.

Impacts of extreme summers on European ecosystems: a comparative analysis of 2003, 2010 and 2018

In Europe, three widespread extreme summer drought and heat (DH) events have occurred in 2003, 2010 and 2018. These events were comparable in magnitude but varied in their geographical distribution and biomes affected. In this study, we perform a comparative analysis of the impact of the DH events on ecosystem CO₂ fluxes over Europe based on an ensemble of 11 dynamic global vegetation models (DGVMs), and the observation-based FLUXCOM product. We find that all DH events were associated with decreases in net ecosystem productivity (NEP), but the gross summer flux anomalies differ between DGVMs and FLUXCOM. At the annual scale, FLUXCOM and DGVMs indicate close to neutral or above-average land CO₂ uptake in DH2003 and DH2018, due to increased productivity in spring and reduced respiration in autumn and winter compensating for less photosynthetic uptake in summer. Most DGVMs estimate lower gross primary production (GPP) sensitivity to soil moisture during extreme summers than FLUXCOM. Finally, we show that the different impacts of the DH events at continental-scale GPP are in part related to differences in vegetation composition of the regions affected and to regional compensating or offsetting effects from climate anomalies beyond the DH centres. This article is part of the theme issue 'Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.

MiRNA-485-5p, inhibits esophageal cancer cells proliferation and invasion by down-regulating O-linked N-acetylglucosamine transferase

OBJECTIVE

Previous reports suggest that miRNA-485-5p is dysregulated and contributes to tumorigenesis in some cancer types. Nevertheless, the biological role of miRNA-485-5p in esophageal cancer (EC) is not well understood. Additionally, we found that the expression of miR-485-5p in EC tissues was aberrant.

PATIENTS AND METHODS

Quantitative RT-PCR (qRT-PCR) was used to demonstrate the expression of miRNA-485-5p in EC cell lines. Cell counting kit-8 (CCK-8) assay and transwell assay indicated that miRNA-485-5p overexpression inhibited cell proliferation, migration, and invasion in EC cell lines. Additionally, Western blotting, dual-luciferase reporter assay, and rescue assay predicted that O-linked N-acetylglucosamine transferase (OGT) was a direct target of miRNA-485-5p. Moreover, we showed that miRNA-485-5p regulated EC tumorigenesis by down-regulating OGT expression in vitro and in vivo.

RESULTS

The upregulation of miR-485-5p (fold change = 44 and 26 in ECA109 and TE-1, respectively; p<0.001) was showed by qRT-PCR. Compared with the control groups, the expression miR-485-5p significantly suppressed the proliferation, migration, and invasion of EC cells. The bioinformatic analysis predicted that the 3' untranslated region (UTR) of OGT contains one miR-485-5p target sequences. Western blotting and dual-luciferase reporter assay showed that activation of OGT 3'UTR was increased by co-transfection with miR-485-5p. Finally, CCK-8 assay predicted that the rescue effects of OGT expression on miR-485-5p induced inhibition of cell growth and tumor weight in Eca109 and TE1 cells.

CONCLUSIONS

Our results suggest that miRNA-485-5p is a suppressor of EC tumorigenesis and could serve as a novel candidate for therapeutic applications in EC treatment.

KinomeX: a web application for predicting kinome-wide polypharmacology effect of small molecules

MOTIVATION

The large-scale kinome-wide virtual profiling for small molecules is a daunting task by experimental and traditional in silico drug design approaches. Recent advances in deep learning algorithms have brought about new opportunities in promoting this process.

RESULTS

KinomeX is an online platform to predict kinome-wide polypharmacology effect of small molecules based solely on their chemical structures. The prediction is made by a multi-task deep neural network model trained with over 140 000 bioactivity data points for 391 kinases. Extensive computational and experimental validations have been performed. Overall, KinomeX enables users to create a comprehensive kinome interaction network for designing novel chemical modulators, and is of practical value on exploring the previously less studied or untargeted kinases.

AVAILABILITY AND IMPLEMENTATION

KinomeX is available at: https://kinome.dddc.ac.cn.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Direct and seasonal legacy effects of the 2018 heat wave and drought on European ecosystem productivity

In summer 2018, central and northern Europe were stricken by extreme drought and heat (DH2018). The DH2018 differed from previous events in being preceded by extreme spring warming and brightening, but moderate rainfall deficits, yet registering the fastest transition between wet winter conditions and extreme summer drought. Using 11 vegetation models, we show that spring conditions promoted increased vegetation growth, which, in turn, contributed to fast soil moisture depletion, amplifying the summer drought. We find regional asymmetries in summer ecosystem carbon fluxes: increased (reduced) sink in the northern (southern) areas affected by drought. These asymmetries can be explained by distinct legacy effects of spring growth and of water-use efficiency dynamics mediated by vegetation composition, rather than by distinct ecosystem responses to summer heat/drought. The asymmetries in carbon and water exchanges during spring and summer 2018 suggest that future land-management strategies could influence patterns of summer heat waves and droughts under long-term warming.

Neuronal HIF-1α in the nucleus tractus solitarius contributes to ventilatory acclimatization to hypoxia

KEY POINTS

We hypothesized that hypoxia inducible factor 1α (HIF-1α) in CNS respiratory centres is necessary for ventilatory acclimatization to hypoxia (VAH); VAH is a time-dependent increase in baseline ventilation and the hypoxic ventilatory response (HVR) occurring over days to weeks of chronic sustained hypoxia (CH). Constitutive deletion of HIF-1α in CNS neurons in transgenic mice tended to blunt the increase in HVR that occurs in wild-type mice with CH. Conditional deletion of HIF-1α in glutamatergic neurons of the nucleus tractus solitarius during CH significantly decreased ventilation in acute hypoxia but not normoxia in CH mice. These effects are not explained by changes in metabolic rate, nor CO2 , and there were no changes in the HVR in normoxic mice. HIF-1α mediated changes in gene expression in CNS respiratory centres are necessary in addition to plasticity of arterial chemoreceptors for normal VAH.

ABSTRACT

Chronic hypoxia (CH) produces a time-dependent increase of resting ventilation and the hypoxic ventilatory response (HVR) that is called ventilatory acclimatization to hypoxia (VAH). VAH involves plasticity in arterial chemoreceptors and the CNS [e.g. nucleus tractus solitarius (NTS)], although the signals for this plasticity are not known. We hypothesized that hypoxia inducible factor 1α (HIF-1α), an O2 -sensitive transcription factor, is necessary in the NTS for normal VAH. We tested this in two mouse models using loxP-Cre gene deletion. First, HIF-1α was constitutively deleted in CNS neurons (CNS-HIF-1α-/- ) by breeding HIF-1α floxed mice with mice expressing Cre-recombinase driven by the calcium/calmodulin-dependent protein kinase IIα promoter. Second, HIF-1α was deleted in NTS neurons in adult mice (NTS-HIF-1α-/- ) by microinjecting adeno-associated virus that expressed Cre-recombinase in HIF-1α floxed mice. In normoxic control mice, HIF-1α deletion in the CNS or NTS did not affect ventilation, nor the acute HVR (10-15 min hypoxic exposure). In mice acclimatized to CH for 1 week, ventilation in hypoxia was blunted in CNS-HIF-1α-/- and significantly decreased in NTS-HIF-1α-/- compared to control mice (P < 0.0001). These changes were not explained by differences in metabolic rate or CO2 . Immunofluorescence showed that HIF-1α deletion in NTS-HIF-1α-/- was restricted to glutamatergic neurons. The results indicate that HIF-1α is a necessary signal for VAH and the previously described plasticity in glutamatergic neurotransmission in the NTS with CH. HIF-1α deletion had no effect on the increase in normoxic ventilation with acclimatization to CH, indicating this is a distinct mechanism from the increased HVR with VAH.

Leucine promotes the growth of squabs by increasing crop milk protein synthesis through the TOR signaling pathway in the domestic pigeon (Columba livia)

Leucine (Leu) plays a critical regulatory role in protein synthesis, however, the effects and molecular mechanisms of Leu on crop milk protein in the domestic pigeons (Columba livia) are still unknown. Therefore, the study aimed to investigate the effects of dietary Leu supplementation on crop milk protein synthesis and the growth performance of squabs and the possible underlying mechanism. A total of 240 pairs of breeding pigeons (1102.3 ± 9.5 g/pair) were randomly assigned to 1 of 5 treatments, including a positive control (PC) diet that had adequate crude protein (crude protein, CP = 18%; Leu = 1.30%), a negative control (NC) diet that was low in CP (CP = 16%, Leu = 1.30%), and NC diets supplemented with Leu at 0.15%, 0.45%, or 1.05%. Compared with the NC diet, 0.15 to 0.45% Leu supplementation decreased BW loss and increased relative crop weight, crop thickness, and protein levels in the crop tissue and milk of breeding pigeons. However, dietary supplementation with 1.05% Leu inhibited ADFI in breeding pigeons. Dietary supplementation with 0.15 to 0.45% Leu decreased the mortality rate and increased the BW, eviscerated yield, and breast muscle yield of young squabs. The protein expression levels of the target of rapamycin (TOR), ribosomal protein S6 kinase 1 (S6K1), ribosomal protein S6 kinase (S6), eukaryotic initiation factor 4E binding protein 1 (4EBP1), and eukaryotic translation initiation factor 4E (eIF4E) were upregulated in the crop tissue of breeding pigeons in PC, 0.15% and 0.45% Leu-supplemented groups. Collectively, these results indicated that 0.15 to 0.45% Leu supplementation could decrease BW loss, increase milk protein synthesis in the crop of breeding pigeons, and enhance the survival rate and growth performance of young squabs through the TOR signaling pathway.

Targeted disruption of TORC1 retards young squab growth by inhibiting the synthesis of crop milk protein in breeding pigeon (Columba livia)

This study was conducted to explore the regulatory role of the target of rapamycin complex 1 (TORC1) signaling pathway in crop milk synthesis in breeding pigeons (Columba livia). Three groups of breeding pigeons in the lactation period (n = 30 pairs/group) were respectively injected with rapamycin (RAPA, a specific inhibitor of the target of rapamycin complex) at doses of 0 (vehicle, control), 0.6, or 1.2 mg/kg body weight (BW)/day via the wing vein for 7 days. The average daily feed intake (ADFI) and BW of the breeding pigeons and the BW of young squabs were respectively recorded throughout the experimental period. The breeding pigeons were sacrificed to collect their crop tissues, crop milk, and serum on the eighth day of the experiment. The results showed that neither 0.6 nor 1.2 mg/kg BW RAPA injection affected BW loss or ADFI in breeding pigeons (P > 0.05), while crop thickness and crop relative weight were significantly decreased (P < 0.05) in the 1.2 mg/kg BW rapamycin-injected group. Simultaneously, RAPA (especially at 1.2 mg/kg BW) decreased the crude protein, αs1-casein, αs2-casein, β-casein, and amino acid contents (Asp, Thr, Ser, Glu, Gly, Ala, Cys, Val, Met, Ile, Leu, Tyr, Lys, His, Arg, and Pro) of crop milk (P < 0.05) and the concentrations of albumin, total protein, and uric acid in the serum of breeding pigeons (P < 0.05). Additionally, the expression of TORC1 pathway-related proteins (TORC1, S6K1, S6, 4EBP1, and eIF4E) was downregulated in the crop tissues of breeding pigeons by 0.6 or 1.2 mg/kg BW/day RAPA injection (P < 0.05). Accordingly, the average daily gain (ADG) of young squabs declined, and the mortality rate increased significantly (P < 0.05). Together, the results showed that RAPA reduced protein and amino acid levels in the crop milk of breeding pigeons and retarded young squab growth, suggesting a crucial role of TORC1 in crop milk synthesis in breeding pigeons.

Investigation of the remote acyl group participation in glycosylation from conformational perspectives by using trichloroacetimidate as the acetyl surrogate

The remote acyl group participation in glycosylation was studied by using trichloroacetimidate as the acetyl surrogate. The bridging participation intermediates were systematically trapped, and DFT calculations were applied to explain the results.

Optimizing chemical reaction conditions using deep learning: a case study for the Suzuki–Miyaura cross-coupling reaction

Deep learning was used to optimize chemical reactions with the quantum mechanical properties of chemical contexts and reaction conditions as inputs. The trained deep learning model determines optimal reaction conditions by in silico exploration of accessible reaction space.