Preparation and characterization of a novel triple composite scaffold containing silk fibroin, chitosan, extracellular matrix and the mechanism of Akt/FoxO signaling pathway in colonic cancer cells cultured in 3D

This work examined the physical and chemical properties and biocompatibility in vivo and in vitro of a unique triple composite scaffold incorporating silk fibroin, chitosan, and extracellular matrix. The materials were blended, cross-linked, and freeze-dried to create a composite scaffold of silk fibroin/chitosan/colon extracellular matrix (SF/CTS/CEM) with varying CEM contents. The SF/CTS/CEM (1:1:1) scaffold demonstrated the preferable shape, outstanding porosity, favorable connectivity, good moisture absorption, and acceptable and controlled swelling and degradation properties. Additionally, HCT-116 cells cultivated with SF/CTS/CEM (1:1:1) showed excellent proliferation capacity, cell malignancy, and delayed apoptosis, according to the in vitro cytocompatibility examination. We also examined the PI3K/PDK1/Akt/FoxO signaling pathway and discovered that cell culture using a SF/CTS/CEM (1:1:1) scaffold may prevent cell death by phosphorylating Akt and suppressing FoxO expression. Our findings demonstrate the potential of the SF/CTS/CEM (1:1:1) scaffold as an experimental model for colonic cancer cell culture and for replicating the three-dimensional in vivo cell growth environment.

Geriatric Services Hub - A Collaborative Frailty Management Model between The Hospital and Community Providers

BACKGROUND

Frailty is an important geriatric syndrome especially with ageing populations. Frailty can be managed or even reversed with community-based interventions delivered by a multi-disciplinary team. Innovation is required to find community frailty models that can deliver cost-effective and feasible care to each local context.

OBJECTIVES

We share pilot data from our Geriatric Service Hub (GSH) which is a novel frailty care model in Singapore that identifies and manages frailty in the community, supported by a hospital-based multi-disciplinary team.

METHODS

We describe in detail our GSH model and its implementation. We performed a retrospective data analysis on patient characteristics, uptake, prevalence of frailty and sarcopenia and referral rates for multi-component interventions.

RESULTS

A total of 152 persons attended between January 2020 to May 2021. Majority (59.9%) were female and mean age was 81.0 ± 7.1 years old. One-fifth (21.1%) of persons live alone. Mean Charlson Co-morbidity Index was 5.2 ± 1.8. Based on the clinical frailty risk scale (CFS), 31.6% were vulnerable, 51.3% were mildly frail and 12.5% were moderately frail. Based on SARC-F screening, 45.3% were identified to be sarcopenic whilst 56.9% had a high concern about falling using the Falls-Efficacy Scale-International. BMD scans were done for 41.4% of participants, of which 58.7% were started on osteoporosis treatment. In terms of referrals to allied health professionals, 87.5% were referred for physiotherapy, 71.1% for occupational therapy and 50.7% to dieticians.

CONCLUSION

The GSH programme demonstrates a new local model of partnering with community service providers to bring comprehensive population level frailty screening and interventions to pre-frail and frail older adults. Our study found high rates of frailty, sarcopenia and fear of falling in community-dwelling older adults who were not presently known to geriatric care services.

Designing High Interfacial Conduction beyond Bulk via Engineering the Semiconductor-Ionic Heterostructure CeO2-δ/BaZr0.8Y0.2O3 for Superior Proton Conductive Fuel Cell and Water Electrolysis Applications

Proton ceramic fuel cells (PCFCs) are an emerging clean energy technology; however, a key challenge persists in improving the electrolyte proton conductivity, e.g., around 10^-3-10^-2 S cm^-1 at 600 °C for the well-known BaZr_0.8Y_0.2O₃ (BZY), that is far below the required 0.1 S cm^-1. Herein, we report an approach for tuning BZY from low bulk to high interfacial conduction by introducing a semiconductor CeO_2-δ forming a semiconductor-ionic heterostructure CeO_2-δ/BZY. The interfacial conduction was identified by a significantly higher conductivity obtained from the BZY grain boundary than that of the bulk and a further improvement from the CeO_2-δ/BZY which achieved a remarkably high proton conductivity of 0.23 S cm^-1. This enabled a high peak power of 845 mW cm^-2 at 520 °C from a PCFC using the CeO_2-δ/BZY as the electrolyte, in strong contrast to the BZY bulk conduction electrolyte with only 229 mW cm^-2. Furthermore, the CeO_2-δ/BZY fuel cell was operated under water electrolysis mode, exhibiting a very high current density output of 3.2 A cm^-2 corresponding to a high H₂ production rate, under 2.0 V at 520 °C. The band structure and a built-in-field-assisted proton transport mechanism have been proposed and explained. This work demonstrates an efficient way of tuning the electrolyte from low bulk to high interfacial proton conduction to attain sufficient conductivity required for PCFCs, electrolyzers, and other advanced electrochemical energy technologies.

Antibiotic-impregnated calcium sulfate for the treatment of pediatric hematogenous osteomyelitis

BACKGROUND

Antibiotic-impregnated calcium sulfate has excellent curative efficacy in chronic osteomyelitis. However, its curative efficacy in pediatric hematogenous osteomyelitis has not been sufficiently studied. The purpose of this study was to evaluate the curative effects of antibiotic-impregnated calcium sulfate in the treatment of pediatric hematogenous osteomyelitis.

METHODS

Overall, twenty-one pediatric patients with hematogenous osteomyelitis treated at our hospital between 2013 and 2018 were included for assessment. The clinical history, clinical manifestation, infection recurrence rate, sinus leakage, incision leakage, pathological fractures, bone growth and surgical procedures were analyzed.

RESULTS

The infection recurrence rate was 0% (0/21) at a minimum of 31 months (range 31 to 91 months) of follow-up. Postoperative incision leakage was found in one pediatric patient. Osteolysis was found in one pediatric patient. Acceleration of bone growth occurred in one pediatric patient. Retardation of bone growth occurred in one pediatric patient. Genu valgus deformity occurred in one pediatric patient.

CONCLUSIONS

Although noninfectious complications occurred, the curative effect of antibiotic-impregnated calcium sulfate in pediatric hematogenous osteomyelitis was satisfactory.

Risk factors and long-term prognosis for postoperative hypoxemia in patients with acute type A aortic dissection: A retrospective observational study

Hypoxemia is 1 of the most common complications in the patients with acute Type A aortic dissection (ATAAD). This study aimed to summarize the risk factors, management strategies and long-term prognosis for postoperative hypoxemia in ATAAD patients. Baseline characteristics and clinical data of all the patients were collected. Patients were divided into 2 groups according to the PaO2/FiO2 after surgery: Hypoxemia group (n = 142) and Non-hypoxemia group (n = 68). The differences in gender, age, body mass index, operation time, cardiopulmonary bypass (CPB) time, aortic cross-clamping time, deep hypothermic circulatory arrest time, preoperative PaO2/FiO2, postoperative PaO2/FiO2, PaO2/FiO2 before extubating, time of mechanical ventilation, length of intensive care unit stay, length of hospital stay, in-hospital mortality, and overall mortality were compared between the 2 groups. The incidence of postoperative hypoxemia in this study was 67.6% (142/210). body mass index (26.4 ± 3.8 vs 24.4 ± 3.3kg/m2, P < .001) in the hypoxemia group were markedly higher and CPB time (196.3 ± 41.0 vs 181.0 ± 37.3 minutes, P = .010) in the hypoxemia group were significantly longer than those in the non-hypoxemia group. While preoperative PaO2/FiO2 (229.7 ± 91.4 vs 299.7 ± 101.2mmHg, P < .001) was significantly lower than those in the non-hypoxemia group. In the hypoxemia group, PaO2/FiO2 before extubating was significantly higher than that after operation, and the difference was significant. Logistic regression analysis showed that overweight (odds ratio [OR]: 1.113, P = .030), CPB time (OR: 1.009, P = .043) and preoperative PaO2/FiO2 (OR: 0.994, P = .001) were independent risk factors for postoperative hypoxemia. Further follow-up results showed no significant difference in long-term mortality between the 2 groups. Logistic regression analysis revealed that PaO2/FiO2 before extubating (OR: 0.985, P < .001), paraplegia (OR: 10.994, P = .019), acute renal failure (OR: 12.590, P < .001), re-operation (OR: 4.721, P = .014) and re-admission to intensive care unit (OR: 13.727, P = .001) were independent risk factors for long-term mortality. Our results showed that overweight and prolonged CPB time were risk factors for postoperative hypoxemia in ATAAD patients. While PaO2/FiO2 before extubating were independent risk factors for long-term mortality, indicating that active correction of hypoxemia and maintain a higher PaO2/FiO2 before extubating may help to improve the prognosis of the ATAAD patients.

zVAD alleviates experimental autoimmune hepatitis in mice by increasing the sensitivity of macrophage to TNFR1-dependent necroptosis

BACKGROUND & AIMS

Autoimmune hepatitis (AIH) is characterized by hepatocyte destruction, leading to lymphocyte and macrophage accumulation in the liver. Macrophages are key drivers of AIH. A membrane-permeable pan-caspase inhibitor, Z-Val-Ala-DL-Asp-fluoromethylketone (zVAD), induces macrophage necroptosis in response to certain stimuli. However, the function of zVAD in the pathogenesis of autoimmune hepatitis remains elusive. In this study, we aimed to evaluate the effect and explore the underlying mechanisms of zVAD against AIH.

METHODS

Murine acute autoimmune liver injury was established by concanavalin A (ConA) injection. Bone marrow-derived macrophages (BMDMs) were used in adoptive cell transfer experiments. The mechanism of action of zVAD was examined using macrophage cell lines and BMDMs. Phosphorylation of mixed lineage kinase domain-like proteins was used as a marker of necroptosis.

RESULTS

Treatment with zVAD increased necroptosis, reduced inflammatory cytokine production, and alleviated liver injury in a ConA-induced liver injury mouse model. Regardless of zVAD treatment, macrophage deletion resulted in reduced neutrophil accumulation and relieved ConA-induced liver injury. In vitro studies have shown that zVAD pretreatment promotes lipopolysaccharide-induced macrophage necroptosis and leads to reduced pro-inflammatory cytokine and chemokine secretion. Transferring zVAD-pretreated BMDMs in mice notably reduced ConA-associated liver inflammation and injury, resulting in lower mortality than that observed after transferring normal BMDMs. Mechanistically, zVAD treatment increased the expression of tumour necrosis factor receptor (TNFR)-1 and interleukin (IL)-10 in macrophages. TNFR1 expression decreased upon transfection with IL-10-specific small interfering RNAs and blocking of TNFR1 decreased macrophage necroptosis.

CONCLUSIONS

We found that zVAD alleviated ConA-induced liver injury by increasing the sensitivity of macrophages to necroptosis via IL-10-induced TNFR1 expression. This study provides new insights into the treatment of autoimmune hepatitis via zVAD-induced macrophage necroptosis.

Reconstruction of aortic sinus using patches in patients with acute type A aortic dissection

OBJECTIVES

Acute type A aortic dissection involving the aortic sinus is often combined with varying degrees of aortic regurgitation, while the structure of the aortic valve is often undamaged. The aim of this study was to evaluate the clinical effects of reconstruction of the aortic sinus using patches in patients with acute type A aortic dissection.

METHODS

From January 2016 to December 2019, 52 patients with acute type A aortic dissection involving the aortic sinus were treated with aortic sinus reconstruction using pericardial or artificial vascular patches. The clinical and follow-up data were summarized.

RESULTS

Bovine pericardial patches were used in 31 cases and artificial vascular patches were used in 21 cases for aortic sinus reconstruction. Cardiopulmonary bypass time was (250.4 ± 65.7) min, aortic cross clamp time was (143.7 ± 42.3) min, and hypothermic circulatory arrest time was (9.6 ± 8.1) min. Three patients died in hospital, with a mortality rate of 5.8%. Fifteen patients (28.8%) had mild postoperative aortic regurgitation. The follow-up duration was 40 ± 12 (range, 21-66) months. Five patients (10.2%) developed moderate to severe aortic regurgitation and 3 (6.1%) died during the follow-up period.

CONCLUSIONS

The application of patches for aortic sinus reconstruction is a relatively easy method in aortic valve-sparing root reconstruction for acute type A aortic dissection involving the aortic sinus. The clinical and follow-up results are favorable.

A Novel Inflammation-Based Risk Score Predicts Mortality in Acute Type A Aortic Dissection Surgery: The Additive Anti-inflammatory Action for Aortopathy and Arteriopathy Score

OBJECTIVE

To develop an inflammation-based risk stratification tool for operative mortality in patients with acute type A aortic dissection.

METHODS

Between January 1, 2016 and December 31, 2021, 3124 patients from Beijing Anzhen Hospital were included for derivation, 571 patients from the same hospital were included for internal validation, and 1319 patients from other 12 hospitals were included for external validation. The primary outcome was operative mortality according to the Society of Thoracic Surgeons criteria. Least absolute shrinkage and selection operator regression were used to identify clinical risk factors. A model was developed using different machine learning algorithms. The performance of the model was determined using the area under the receiver operating characteristic curve (AUC) for discrimination, calibration curves, and Brier score for calibration. The final model (5A score) was tested with respect to the existing clinical scores.

RESULTS

Extreme gradient boosting was selected for model training (5A score) using 12 variables for prediction-the ratio of platelet to leukocyte count, creatinine level, age, hemoglobin level, prior cardiac surgery, extent of dissection extension, cerebral perfusion, aortic regurgitation, sex, pericardial effusion, shock, and coronary perfusion-which yields the highest AUC (0.873 [95% confidence interval (CI) 0.845-0.901]). The AUC of 5A score was 0.875 (95% CI 0.814-0.936), 0.845 (95% CI 0.811-0.878), and 0.852 (95% CI 0.821-0.883) in the internal, external, and total cohort, respectively, which outperformed the best existing risk score (German Registry for Acute Type A Aortic Dissection score AUC 0.709 [95% CI 0.669-0.749]).

CONCLUSION

The 5A score is a novel, internally and externally validated inflammation-based tool for risk stratification of patients before surgical repair, potentially advancing individualized treatment.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT04918108.

Entropy Driving the Mg2+-Induced Folding of TPP Riboswitch RNA

Mg²⁺ is well known to facilitate the structural folding of RNA. However, the thermodynamic and dynamic roles of Mg²⁺ in RNA folding remain elusive. Here, we exploit single-molecule fluorescence resonance energy transfer (smFRET) and isothermal titration calorimetry (ITC) to study the mechanism of Mg²⁺ in facilitating the folding of thiamine pyrophosphate (TPP) riboswitch RNA. The results of smFRET identify that the presence of Mg²⁺ compacts the RNA and enlarges the conformational dispersity among individual RNA molecules, resulting in a large gain of entropy. The compact yet flexible conformations triggered by Mg²⁺ may help the riboswitch recognize its specific ligand and further fold. This is supported by the ITC experiments, in which the Mg²⁺-induced RNA folding is driven by entropy (ΔS) instead of enthalpy (ΔH). Our results complement the understanding of the Mg²⁺-induced RNA folding. The strategy developed in this work can be used to model other RNAs' folding under different conditions.

Does bariatric surgery change the risk of acute ischemic stroke in patients with a history of transient ischemic attack? A nationwide analysis

BACKGROUND

Stroke is the second leading cause of death worldwide and fifth in the United States, and it represents the major cause of disability in older adults.

OBJECTIVE

We aimed to determine the risk of acute ischemic stroke (AIS) in individuals with obesity with a history of transient ischemic attack (TIA) compared with patients with a history of bariatric surgery.

SETTING

Academic hospital, United States.

METHODS

Using the Nationwide Inpatient Sample (NIS) database from 2010 to 2015, we retrospectively identified patients with obesity and past medical history of TIA and divided them into 2 groups: a treatment group of patients who underwent bariatric surgery, and a control group of patients with obesity. We compared incidence of new AIS in both groups using a univariate analysis and multivariate regression model. Covariates included were lifestyle (smoking status, alcohol habits, cocaine use), family history of stroke, co-morbidities (diabetes, hypertension, hyperlipidemia, atrial fibrillation) and long-term medical treatment (antiplatelet/antithrombotic treatment).

RESULTS

A total of 91,640 patients met inclusion criteria, of which treatment patients were 12.3% (n = 11,284) and control patients 87.6% (n = 80,356). The average age of the treatment group was 62.9 ± 17.08 years, and the average of the control was 59.6 ± 12.74 years. The rate of AIS in the treatment group was significantly lower compared with the control group (2.8% versus 4.2%, P < .0001). After adjusting for covariables, the risk difference of AIS was still significant between groups (odds ratio = 1.33, P < .0001), showing that patients in the treatment group were less likely to have AIS compared with the control group.

CONCLUSIONS

After analyzing nationwide information, we conclude bariatric surgery helps decrease risk of AIS in patients with a history of TIA. However, this comparison is limited by the nature of the database; further studies are needed to better understand these results.

Circulating biomarker-based risk stratifications individualize arch repair strategy of acute Type A aortic dissection via the XGBoosting algorithm

Aims

The incremental usefulness of circulating biomarkers from different pathological pathways for predicting mortality has not been evaluated in acute Type A aortic dissection (ATAAD) patients. We aim to develop a risk prediction model and investigate the impact of arch repair strategy on mortality based on distinct risk stratifications.

Methods and results

A total of 3771 ATAAD patients who underwent aortic surgery retrospectively included were randomly divided into training and testing cohorts at a ratio of 7:3 for the development and validation of the risk model based on multiple circulating biomarkers and conventional clinical factors. Extreme gradient boosting was used to generate the risk models. Subgroup analyses were performed by risk stratifications (low vs. middle-high risk) and arch repair strategies (proximal vs. extensive arch repair). Addition of multiple biomarkers to a model with conventional factors fitted an ABC risk model consisting of platelet-leucocyte ratio, mean arterial pressure, albumin, age, creatinine, creatine kinase-MB, haemoglobin, lactate, left ventricular end-diastolic dimension, urea nitrogen, and aspartate aminotransferase, with adequate discrimination ability {area under the receiver operating characteristic curve (AUROC): 0.930 [95% confidence interval (CI) 0.906-0.954] and 0.954, 95% CI (0.930-0.977) in the derivation and validation cohort, respectively}. Compared with proximal arch repair, the extensive repair was associated with similar mortality risk among patients at low risk [odds ratio (OR) 1.838, 95% CI (0.559-6.038); P = 0.316], but associated with higher mortality risk among patients at middle-high risk [OR 2.007, 95% CI (1.460-2.757); P < 0.0001].

Conclusion

In ATAAD patients, the simultaneous addition of circulating biomarkers of inflammatory, cardiac, hepatic, renal, and metabolic abnormalities substantially improved risk stratification and individualized arch repair strategy.

The role of Phe150 in human voltage-gated proton channel

The voltage-gated proton channel H_v1 is a member of voltage-gated ion channels containing voltage-sensing domains (VSDs). The VSDs are made of four membrane-spanning segments (S1 through S4), and their function is to detect changes in membrane potential in the cells. A highly conserved phenylalanine 150 (F150) is located in the S2 segment of human voltage-gated proton channels. We previously discovered that the F150 is a binding site for the open channel blocker 2GBI. Here, we show that the H_v1 VSD voltage-dependent activation requires a hydrophobic group at position F150. We perform double-mutant cycle analysis to probe interactions between F150 and positively charged arginines in the S4 segment of the channel. Our results indicate that F150 interacts with two arginines (R2 and R3) in the S4 segment and catalyzes the transfer of the S4 arginines in the process of voltage-dependent activation.

•

Hydrophobicity of F150 is crucial for human H_v1 channel voltage-dependent activation

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F150 interacts with R2 to stabilize the closed state of the H_v1 channel

•

When depolarized, R3 moves upward to interact with F150 stabilizing the open state of H_v1

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F150 is essential for the transfer of the H_v1 arginines in the process of voltage sensing

Role of a lipid metabolism-related lncRNA signature in risk stratification and immune microenvironment for colon cancer

Background

Energy metabolism disorder, especially lipid metabolism disorder, is an important biological characteristic of colon cancer. This research sought to examine the association between lipid metabolism-related long non-coding RNAs (lncRNAs) and prognoses among colon cancer patients.

Methods

The transcriptome profile and clinical data of patients with colon cancer were retrieved from The Cancer Genome Atlas database. Using consensus clustering, cases were divided into two clusters and Kaplan–Meier analysis was executed to analyze differences in their prognoses. The gene set enrichment analysis (GSEA) was used to discover biological processes and signaling pathways. A lipid metabolism-related lncRNA prognostic model (lipid metabolism-LncRM) was created utilizing the least absolute shrinkage and selection operator (LASSO) regression. The tumor microenvironment was evaluated on the basis of the composition of immune and stromal cells.

Results

The patients in Cluster 2 were found to have a better prognosis and higher expression of programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) relative to Cluster 1. The results of GSEA showed the enrichment of energy metabolism pathways in Cluster 2. LASSO regression was used to identify the five LncRNAs that were shown to be most substantially linked to patient prognosis. These were NSMCE1-DT, LINC02084, MYOSLID, LINC02428, and MRPS9-AS1. Receiver operating characteristic (ROC) curves and survival analysis illustrated that the lipid metabolism-LncRM had a significant prognostic value. Further analysis showed that high- and low-risk groups were significantly different in terms of clinical characteristics and immune cells infiltration.

Conclusions

Lipid metabolism-related lncRNAs could predict the prognoses and tumor microenvironment of colon cancer and might be important biomarkers relevant to immunotherapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01369-8.

Comprehensive analysis of transient receptor potential channels-related signature for prognosis, tumor immune microenvironment, and treatment response of colorectal cancer

BACKGROUND

Transient receptor potential channels (TRPC) play critical regulatory functions in cancer occurrence and progression. However, knowledge on its role in colorectal cancer (CRC) is limited. In addition, neoadjuvant treatment and immune checkpoint inhibitors (ICIs) have increasing roles in CRC management, but not all patients benefit from them. In this study, a TRPC related signature (TRPCRS) was constructed for prognosis, tumor immune microenvironment (TIME), and treatment response of CRC.

METHODS

Data on CRC gene expression and clinical features were retrospectively collected from TCGA and GEO databases. Twenty-eight TRPC regulators (TRPCR) were retrieved using gene set enrichment analysis. Different TRPCR expression patterns were identified using non-negative matrix factorization for consensus clustering, and a TRPCRS was established using LASSO. The potential value of TRPCRS was assessed using functional enrichment analysis, tumor immune analysis, tumor somatic mutation analysis, and response to preoperative chemoradiotherapy or ICIs. Moreover, an external validation was conducted using rectal cancer samples that received preoperative chemoradiotherapy at Fujian Cancer Hospital (FJCH) via qRT-PCR.

RESULTS

Among 834 CRC samples in the TCGA and meta-GEO cohorts, two TRPCR expression patterns were identified, which were associated with various immune infiltrations. In addition, 266 intersected genes from 5564 differentially expressed genes (DEGs) between two TRPC subtypes, 4605 DEGs between tumor tissue and adjacent non-tumor tissue (all FDR< 0.05, adjusted P< 0.001), and 1329 prognostic related genes (P< 0.05) were identified to establish the TRPCRS, which was confirmed in the TCGA cohort, two cohorts from GEO, and one qRT-PCR cohort from FJCH. According to the current signature, the high-TRPC score group had higher expressions of PD-1, PD-L1, and CTLA4, lower TIDE score, and improved response to anti-PD-1 treatment with better predictive ability. Compared to the high-TRPC score group, the low-TRPC score group comprised an immunosuppressive phenotype with increased infiltration of neutrophils and activated MAPK signaling pathway, but was more sensitive to preoperative chemoradiotherapy and associated with improved prognosis.

CONCLUSIONS

The current TRPCRS predicted the prognosis of CRC, evaluated the TIME in CRC, and anticipated the response to immune therapy and neoadjuvant treatment.

A random batch Ewald method for charged particles in the isothermal-isobaric ensemble

We develop an accurate, highly efficient, and scalable random batch Ewald (RBE) method to conduct molecular dynamics simulations in the isothermal-isobaric ensemble (the NPT ensemble) for charged particles in a periodic box. After discretizing the Langevin equations of motion derived using suitable Lagrangians, the RBE method builds the mini-batch strategy into the Fourier space in the Ewald summation for the pressure and forces such that the computational cost is reduced to O(N) per time step. We implement the method in the Large-scale Atomic/Molecular Massively Parallel Simulator package and report accurate simulation results for both dynamical quantities and statistics for equilibrium for typical systems including all-atom bulk water and a semi-isotropic membrane system. Numerical simulations on massive supercomputing cluster are also performed to show promising central processing unit efficiency of the RBE.

Discovery of an autophagy inducer J3 to lower mutant huntingtin and alleviate Huntington's disease-related phenotype

Huntington’s disease (HD) is a neurodegenerative disorder caused by aggregation of the mutant huntingtin (mHTT) protein encoded from extra tracts of CAG repeats in exon 1 of the HTT gene. mHTT proteins are neurotoxic to render the death of neurons and a series of disease-associated phenotypes. The mHTT is degraded through autophagy pathway and ubiquitin–proteasome system (UPS). This study identified a small molecule, J3, as an autophagy inducer by high-content screening. The results revealed that J3 could inhibit mTOR, thus promoting autophagic flux and long-lived protein degradation. Further, J3 selectively lowered the soluble and insoluble mHTT but not wild type HTT levels in cell models. The HdhQ140 mice showed reduced HD-associated activity and loss of motor functions. However, administration of J3 showed increased activity and a slight improvement in the motor function in the open-field test, balance beam test, and rotarod tests. Furthermore, in vivo studies revealed that J3 decreased T-HTT and misfolded protein levels in the striatum and increased the levels of the medium spiny neuron marker DARPP-32. In addition, J3 showed good permeability across the brain-blood barrier efficiently, suggesting that J3 was a promising candidate for the treatment of HD.

Conduction Mechanism in Graphene Oxide Membranes with Varied Water Content: From Proton Hopping Dominant to Ion Diffusion Dominant

Proton conductors, particularly hydrated solid membranes, have various applications in sensors, fuel cells, and cellular biological systems. Unraveling the intrinsic proton transfer mechanism is critical for establishing the foundation of proton conduction. Two scenarios on electrical conduction, the Grotthuss and the vehicle mechanisms, have been reported by experiments and simulations. But separating and quantifying the contributions of these two components from experiments is difficult. Here, we present the conductive behavior of a two-dimensional layered proton conductor, graphene oxide membrane (GOM), and find that proton hopping is dominant at low water content, while ion diffusion prevails with increasing water content. This change in the conduction mechanism is attributable to the layers of water molecules in GOM nanosheets. The overall conductivity is greatly improved by forming one layer of water molecules. It reaches the maximum with two layers of water molecules, resulting from creating a complete hydrogen-bond network within GOM. When more than two layers of water molecules enter the GOM nanosheets, inducing the breakage of the ordered lamellar structure, protons spread in both in-plane and out-of-plane directions inside the GOM. Our results validate the existence of two conduction mechanisms and show their distinct contributions to the overall conductivity. Furthermore, these findings provide an optimization strategy for the design of realizing the fast proton transfer in materials with water participation.

Self-supervised contrastive learning for integrative single cell RNA-seq data analysis

We present a novel self-supervised Contrastive LEArning framework for single-cell ribonucleic acid (RNA)-sequencing (CLEAR) data representation and the downstream analysis. Compared with current methods, CLEAR overcomes the heterogeneity of the experimental data with a specifically designed representation learning task and thus can handle batch effects and dropout events simultaneously. It achieves superior performance on a broad range of fundamental tasks, including clustering, visualization, dropout correction, batch effect removal, and pseudo-time inference. The proposed method successfully identifies and illustrates inflammatory-related mechanisms in a COVID-19 disease study with 43 695 single cells from peripheral blood mononuclear cells.

Structure and dynamics of supercooled water in the hydration layer of poly(ethylene glycol)

The statics and dynamics of supercooled water in the hydration layer of poly(ethylene glycol) (PEG) were studied by a combination of quasi-elastic neutron scattering (QENS) and molecular dynamics (MD) simulations. Two samples, that is, hydrogenated PEG/deuterated water (h-PEG/D₂O) and fully deuterated PEG/hydrogenated water (d-PEG/H₂O) with the same molar ratio of ethylene glycol (EG) monomer to water, 1:1, are compared. The QENS data of h-PEG/D₂O show the dynamics of PEG, and that of d-PEG/H₂O reveals the motion of water. The temperature-dependent elastic scattering intensity of both samples has shown transitions at supercooled temperature, and these transition temperatures depend on the energy resolution of the instruments. Therefore, neither one is a phase transition, but undergoes dynamic process. The dynamic of water can be described as an Arrhenius to super-Arrhenius transition, and it reveals the hydrogen bonding network relaxation of hydration water around PEG at supercooled temperature. Since the PEG-water hydrogen bond structural relaxation time from MD is in good agreement with the average relaxation time from QENS (d-PEG/H₂O), MD may further reveal the atomic pictures of the supercooled hydration water. It shows that hydration water molecules form a series of pools around the hydrophilic oxygen atom of PEG. At supercooled temperature, they have a more bond ordered structure than bulk water, proceed a trapping sites diffusion on the PEG surface, and facilitate the structural relaxation of PEG backbone.

Prediction of low cardiac output syndrome in patients following cardiac surgery using machine learning

Background

This study aimed to develop machine learning models to predict Low Cardiac Output Syndrome (LCOS) in patients following cardiac surgery using machine learning algorithms.

Methods

The clinical data of cardiac surgery patients in Nanjing First Hospital between June 2019 and November 2020 were retrospectively extracted from the electronic medical records. Six conventional machine learning algorithms, including logistic regression, support vector machine, decision tree, random forest, extreme gradient boosting and light gradient boosting machine, were employed to construct the LCOS predictive models with all predictive features (full models) and selected predictive features (reduced models). The discrimination of these models was evaluated by the area under the receiver operating characteristic curve (AUC) and the calibration of the models was assessed by the calibration curve. Shapley Additive explanation (SHAP) and Local Interpretable Model-Agnostic Explanations (LIME) were used to interpret the predictive models.

Results

Data from 1,585 patients [982 (62.0%) were male, aged 18 to 88, 212 (13.4%) with LCOS] were employed to train and validate the LCOS models. Among the full models, the RF model (AUC: 0.909, 95% CI: 0.875–0.943; Sensitivity: 0.849, 95% CI: 0.724–0.933; Specificity: 0.835, 95% CI: 0.796–0.869) and the XGB model (AUC: 0.897, 95% CI: 0.859–0.935; Sensitivity: 0.830, 95% CI: 0.702–0.919; Specificity: 0.809, 95% CI: 0.768–0.845) exhibited well predictive power for LCOS. Eleven predictive features including left ventricular ejection fraction (LVEF), first post-operative blood lactate (Lac), left ventricular diastolic diameter (LVDd), cumulative time of mean artery blood pressure (MABP) lower than 65 mmHg (MABP &lt; 65 time), hypertension history, platelets level (PLT), age, blood creatinine (Cr), total area under curve above threshold central venous pressure (CVP) 12 mmHg and 16 mmHg, and blood loss during operation were used to build the reduced models. Among the reduced models, RF model (AUC: 0.895, 95% CI: 0.857–0.933; Sensitivity: 0.830, 95% CI: 0.702–0.919; Specificity: 0.806, 95% CI: 0.765–0.843) revealed the best performance. SHAP and LIME plot showed that LVEF, Lac, LVDd and MABP &lt; 65 time significantly contributed to the prediction model.

Conclusion

In this study, we successfully developed several machine learning models to predict LCOS after surgery, which may avail to risk stratification, early detection and management of LCOS after cardiac surgery.

Fibrosis Risk in Nonalcoholic Fatty Liver Disease Is Related to Chronic Kidney Disease in Older Type 2 Diabetes Patients

CONTEXT

Nonalcoholic fatty liver disease (NAFLD) is a multisystem disease, associated with fibrosis and an increased risk of type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD).

OBJECTIVE

This work aimed to investigate the association of NAFLD fibrosis with the development of CKD in aged patients with T2DM.

METHODS

This cross-sectional study enrolled 13 915 participants. A further 1734 individuals who had been followed annually for 5 years comprised the retrospective cohort study. Noninvasive markers, NAFLD fibrosis score (NFS), and fibrosis index based on 4 factors (FIB-4) were applied to determine NAFLD fibrosis risk.

RESULTS

In the cross-sectional study, there was an additive interaction for NAFLD with increased risk of fibrosis and T2DM on CKD incidence. Logistic regression demonstrated that as NAFLD fibrosis risk progressed from low to intermediate and high, there was a stepwise increase in CKD in patients with NAFLD, T2DM, and those with coexistent NAFLD and T2DM when stratified by diabetes and fibrosis stage. FIB-4 had a much higher odds ratio (OR) value than NFS for prediction of CKD incidence. In the cohort study, individuals were grouped according to FIB-4 and NFS. Cox regression analysis showed that FIB-4 intermediate risk (hazard ratio [HR] 1.268; 95% CI, 1.056-1.521) and high risk (HR 2.516; 95% CI, 1.970-3.214) were significant predictors of CKD progression. When NFS was applied, only high risk was a significant predictor.

CONCLUSION

NAFLD with an increased risk of fibrosis and presence of T2DM had an additive interaction on CKD incidence. Increased risk of NAFLD fibrosis was closely associated with CKD incidence and progression in aged T2DM patients. FIB-4 outperformed NFS as a noninvasive means to predict CKD development.