Discovery of meisoindigo derivatives as noncovalent and orally available Mpro inhibitors: their therapeutic implications in the treatment of COVID-19

The progressive emergence of SARS-CoV-2 variants has necessitated the urgent exploration of novel therapeutic strategies to combat the COVID-19 pandemic. The SARS-CoV-2 main protease (Mpro) represents an evolutionarily conserved therapeutic target for drug discovery. This study highlights the discovery of meisoindigo (Mei), derived from the traditional Chinese medicine (TCM) Indigo naturalis, as a novel non-covalent and nonpeptidic Mpro inhibitor. Substantial optimizations and structure-activity relationship (SAR) studies, guided by a structure-based drug design approach, led to the identification of several Mei derivatives, including S5-27 and S5-28, exhibiting low micromolar inhibition against SARS-CoV-2 Mpro with high binding affinity. Notably, S5-28 provided significant protection against wild-type SARS-CoV-2 in HeLa-hACE2 cells, with EC50 up to 2.66 μM. Furthermore, it displayed favorable physiochemical properties and remarkable gastrointestinal and metabolic stability, demonstrating its potential as an orally bioavailable drug for anti-COVID-19 therapy. This research presents a promising avenue for the development of new antiviral agents, offering hope in the ongoing battle against COVID-19.

Discovery of a Meisoindigo-Derived PROTAC as the ATM Degrader: Revolutionizing Colorectal Cancer Therapy via Synthetic Lethality with ATR Inhibitors

Meisoindigo (Mei) has long been recognized in chronic myeloid leukemia (CML) treatment. To elucidate its molecular target and mechanisms, we embarked on designing and synthesizing a series of Mei-derived PROTACs. Through this endeavor, VHL-type PROTAC 9b was identified to be highly cytotoxic against SW620, SW480, and K562 cells. Employing DiaPASEF-based quantitative proteomic analysis, in combination with extensive validation assays, we unveiled that 9b potently and selectively degraded ATM across SW620 and SW480 cells in a ubiquitin-proteasome-dependent manner. 9b-induced selective ATM degradation prompted DNA damage response cascades, thereby leading to the cell cycle arrest and cell apoptosis. This pioneering discovery renders the advent of ATM degradation for anti-cancer therapy. Notably, 9b-induced ATM degradation synergistically enhanced the efficacy of ATR inhibitor AZD6738 both in vitro and in vivo. This work establishes the synthetic lethality-inducing properties of ATR inhibitors in the ATM-deficient context, thereby providing new avenues to innovative therapies for colorectal cancer.

Multiparametric MRI-based radiomics nomogram for predicting malignant transformation of sinonasal inverted papilloma

AIM

To investigate the feasibility of a radiomics nomogram model for predicting malignant transformation in sinonasal inverted papilloma (IP) based on radiomic signature and clinical risk factors.

MATERIALS AND METHODS

This single institutional retrospective review included a total of 143 patients with IP and 75 patients with IP with malignant transformation to squamous cell carcinoma (IP-SCC). All patients underwent surgical pathology and had preoperative magnetic resonance imaging (MRI) and computed tomography (CT) sinus studies between June 2014 and February 2022. Radiomics features were extracted from contrast-enhanced T1-weighted images (CE-T1WI), T2-weighted images (T2WI), and apparent diffusion coefficient (ADC) maps. The least absolute shrinkage and selection operator (LASSO) were performed to select the features extracted from the sequences mentioned above. Independent clinical risk factors were identified by multivariate logistic regression analysis. Radiomics nomogram was constructed by incorporating independent clinical risk factors and radiomics signature. Based on discrimination and calibration, the diagnostic performance of the nomogram was evaluated.

RESULTS

Twelve radiomics features were selected to develop the radiomics model with an area under the curve (AUC) of 0.987 and 0.989, respectively. Epistaxis (p=0.011), T2 equal signal (p=0.003), extranasal invasion (p<0.001), and loss of convoluted cerebriform pattern (p=0.002) were identified as independent clinical predictors. The radiomics nomogram model showed excellent calibration and discrimination (AUC: 0.993, 95% confidence interval [CI]: 0.985-1.00 and 0.990, 95% CI: 0.974-1.00) in the training and validation sets, respectively.

CONCLUSION

The nomogram that the combined radiomics signature and clinical risk factors showed a satisfactory ability to predict IP-SCC.

Targeting epidermal growth factor receptor signalling pathway: A promising therapeutic option for COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is continuously producing new variants, necessitating effective therapeutics. Patients are not only confronted by the immediate symptoms of infection but also by the long-term health issues linked to long COVID-19. Activation of epidermal growth factor receptor (EGFR) signalling during SARS-CoV-2 infection promotes virus propagation, mucus hyperproduction, and pulmonary fibrosis, and suppresses the host's antiviral response. Over the long term, EGFR activation in COVID-19, particularly in COVID-19-induced pulmonary fibrosis, may be linked to the development of lung cancer. In this review, we have summarised the significance of EGFR signalling in the context of SARS-CoV-2 infection. We also discussed the targeting of EGFR signalling as a promising strategy for COVID-19 treatment and highlighted erlotinib as a superior option among EGFR inhibitors. Erlotinib effectively blocks EGFR and AAK1, thereby preventing SARS-CoV-2 replication, reducing mucus hyperproduction, TNF-α expression, and enhancing the host's antiviral response. Nevertheless, to evaluate the antiviral efficacy of erlotinib, relevant clinical trials involving an appropriate patient population should be designed.

Factors associated with nocturnal and diurnal glycemic variability in patients with type 2 diabetes: a cross-sectional study

PURPOSE

There is little information on factors that influence the glycemic variability (GV) during the nocturnal and diurnal periods. We aimed to examine the relationship between clinical factors and GV during these two periods.

METHODS

This cross-sectional study included 134 patients with type 2 diabetes. 24-h changes in blood glucose were recorded by a continuous glucose monitoring system. Nocturnal and diurnal GV were assessed by standard deviation of blood glucose (SDBG), coefficient of variation (CV), and mean amplitude of glycemic excursions (MAGE), respectively. Robust regression analyses were performed to identify the factors associated with GV. Restricted cubic splines were used to determine dose-response relationship.

RESULTS

During the nocturnal period, age and glycemic level at 12:00 A.M. were positively associated with GV, whereas alanine aminotransferase was negatively associated with GV. During the diurnal period, homeostatic model assessment 2-insulin sensitivity (HOMA2-S) was positively associated with GV, whereas insulin secretion-sensitivity index-2 (ISSI2) was negatively associated with GV. Additionally, we found a J-shape association between the glycemic level at 12:00 A.M. and MAGE, with 9.0 mmol/L blood glucose level as a cutoff point. Similar nonlinear associations were found between ISSI2 and SDBG, and between ISSI2 and MAGE, with ISSI2 value of 175 as a cutoff point.

CONCLUSION

Factors associated with GV were different between nocturnal and diurnal periods. The cutoff points we found in this study may provide the therapeutic targets for beta-cell function and pre-sleep glycemic level in clinical practice.

Hepatocellular Carcinoma Cell-Derived Exosomal miR-21-5p Induces Macrophage M2 Polarization by Targeting RhoB

M2-like polarized tumor-associated macrophages (TAMs) are the major component of infiltrating immune cells in hepatocellular carcinoma (HCC), which have been proved to exhibit significant immunosuppressive and pro-tumoral effects. However, the underlying mechanism of the tumor microenvironment (TME) educating TAMs to express M2-like phenotypes is still not fully understood. Here, we report that HCC-derived exosomes are involved in intercellular communications and exhibit a greater capacity to mediate TAMs' phenotypic differentiation. In our study, HCC cell-derived exosomes were collected and used to treat THP-1 cells in vitro. Quantitative polymerase chain reaction (qPCR) results showed that the exosomes significantly promoted THP-1 macrophages to differentiate into M2-like macrophages, which have a high production of transforming growth factor-β (TGF-β) and interleukin (IL)-10. The analysis of bioinformatics indicated that exosomal miR-21-5p is closely related to TAM differentiation and is associated with unfavorable prognosis in HCC. Overexpressing miR-21-5p in human monocyte-derived leukemia (THP-1) cells induced down-regulation of IL-1β levels; however, it enhanced production of IL-10 and promoted the malignant growth of HCC cells in vitro. A reporter assay confirmed that miR-21-5p directly targeted Ras homolog family member B (RhoB) 3'-untranslatedregion (UTR) in THP-1 cells. Downregulated RhoB levels in THP-1 cells would weaken mitogen-activated protein kinase (MAPK) axis signaling pathways. Taken together, tumor-derived miR-21-5p promote the malignant advance of HCC, which mediated intercellular crosstalk between tumor cells and macrophages. Targeting M2-like TAMs and intercepting their associated signaling pathways would provide potentially specific and novel therapeutic approaches for HCC treatment.

[Analysis of changes in self-efficacy and its influencing factors in type 2 diabetic patients after community-based self-management group intervention]

Objective: To analyze the changes in self-efficacy and its influencing factors in type 2 diabetic patients after community-based self-management group intervention. Methods: From August to November 2014, a 3-month community-based self-management intervention study of type 2 diabetes patients was implemented in Fangshan District, Beijing. 510 patients were recruited through posters, household inquiries and telephone notification and then were randomly divided into intervention group (260 patients) and control group (250 patients). Finally, 500 patients completed the study, including 259 in the intervention group and 241 in the control group. Self-efficacy score was measured through face-to-face interview at different time points, including pre-intervention, post-intervention, 2 years after the intervention and 5 years after the intervention, respectively. A two-level random coefficient model was fitted to analyze the long-term trend of self-efficacy and its relationship with group intervention. Results: Individual-level educational attainment, disease duration as well as their treatment plans had a positive correlation with self-efficacy of type 2 diabetic patients while gender and age did not affect their self-efficacy. Patients with junior middle school education, senior high school education and university and above education had 4.66 (P<0.05), 6.40 (P<0.05) and 11.02 (P<0.05) points higher than those with primary education, respectively. The self-efficacy of diabetic patients increased by 0.23 (P<0.05) for each additional course year. The effect of treatment plan on self-efficacy was mainly reflected in the self-efficacy of taking medication or insulin injection as prescribed and blood glucose monitoring. After controlling for the confounding factors, i.e., gender, age, disease duration, educational attainment, and treatment plan, self-efficacy scores at the post-intervention increased in both groups compared to those at the pre-intervention. The intervention group had 7.95 points higher than the control group (P<0.05). After the intervention, the self-efficacy scores of both groups decreased year by year while the intervention group declined faster, with 5.41 points (P<0.05) at 2 years after the intervention and 8.94 points (P<0.05) at 5 years after the intervention. Conclusion: Community-based self-management group intervention could improve the self-efficacy of type 2 diabetic patients while the self-efficacy decreases year by year in the absence of follow-up intervention.

M6A-mediated upregulation of circMDK promotes tumorigenesis and acts as a nanotherapeutic target in hepatocellular carcinoma

Background

Emerging evidence suggest the critical role of circular RNAs (circRNAs) in disease development especially in various cancers. However, the oncogenic role of circRNAs in hepatocellular carcinoma (HCC) is still largely unknown.

Methods

RNA sequencing was performed to identify significantly upregulated circRNAs in paired HCC tissues and non-tumor tissues. CCK-8 assay, colony formation, transwell, and xenograft mouse models were used to investigate the role of circRNAs in HCC proliferation and metastasis. Small interfering RNA (siRNA) was used to silence gene expression. RNA immunoprecipitation, biotin pull-down, RNA pull-down, luciferase reporter assay and western blot were used to explore the underlying molecular mechanisms.

Results

Hsa_circ_0095868, derived from exon 5 of the MDK gene (named circMDK), was identified as a new oncogenic circRNA that was significantly upregulated in HCC. The upregulation of circMDK was associated with the modification of N6-methyladenosine (m⁶A) and poor survival in HCC patients. Mechanistically, circMDK sponged miR-346 and miR-874-3p to upregulate ATG16L1 (Autophagy Related 16 Like 1), resulting to the activation of PI3K/AKT/mTOR signaling pathway to promote cell proliferation, migration and invasion. Poly (β-amino esters) (PAEs) were synthesized to assist the delivery of circMDK siRNA (PAE-siRNA), which effectively inhibited tumor progression without obvious adverse effects in four liver tumor models including subcutaneous, metastatic, orthotopic and patient-derived xenograft (PDX) models.

Conclusions

CircMDK could serve as a potential tumor biomarker that promotes the progression of HCC via the miR-346/874-3p-ATG16L1 axis. The PAE-based delivery of siRNA improved the stability and efficiency of siRNA targeting circMDK. The PAE-siRNA nanoparticles effectively inhibited HCC proliferation and metastasis in vivo. Our current findings offer a promising nanotherapeutic strategy for the treatment of HCC.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-022-01575-z.

An atlas of human viruses provides new insights into diversity and tissue tropism of human viruses

MOTIVATION

Viruses continue to threaten human health. Yet, the complete viral species carried by humans and their infection characteristics have not been fully revealed.

RESULTS

This study curated an atlas of human viruses from public databases and literature, and built the Human Virus Database (HVD). The HVD contains 1,131 virus species of 54 viral families which were more than twice the number of the human-infecting virus species reported in previous studies. These viruses were identified in human samples including 68 human tissues, the excreta and body fluid. The viral diversity in humans was age-dependent with a peak in the infant and a valley in the teenager. The tissue tropism of viruses was found to be associated with several factors including the viral group (DNA, RNA or reverse-transcribing viruses), enveloped or not, viral genome length and GC content, viral receptors and the virus-interacting proteins. Finally, the tissue tropism of DNA viruses was predicted using a random-forest algorithm with a middle performance. Overall, the study not only provides a valuable resource for further studies of human viruses, but also deepens our understanding towards the diversity and tissue tropism of human viruses.

AVAILABILITY

The HVD is available at http://computationalbiology.cn/humanVirusBase/#/.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Microbiome Profiling Using Shotgun Metagenomic Sequencing Identified Unique Microorganisms in COVID-19 Patients With Altered Gut Microbiota

COVID-19 is mainly associated with respiratory distress syndrome, but a subset of patients often present gastrointestinal (GI) symptoms. Imbalances of gut microbiota have been previously linked to respiratory virus infection. Understanding how the gut–lung axis affects the progression of COVID-19 can provide a novel framework for therapies and management. In this study, we examined the gut microbiota of patients with COVID-19 (n = 47) and compared it to healthy controls (n = 19). Using shotgun metagenomic sequencing, we have identified four microorganisms unique in COVID-19 patients, namely Streptococcus thermophilus, Bacteroides oleiciplenus, Fusobacterium ulcerans, and Prevotella bivia. The abundances of Bacteroides stercoris, B. vulgatus, B. massiliensis, Bifidobacterium longum, Streptococcus thermophilus, Lachnospiraceae bacterium 5163FAA, Prevotella bivia, Erysipelotrichaceae bacterium 6145, and Erysipelotrichaceae bacterium 2244A were enriched in COVID-19 patients, whereas the abundances of Clostridium nexile, Streptococcus salivarius, Coprococcus catus, Eubacterium hallii, Enterobacter aerogenes, and Adlercreutzia equolifaciens were decreased (p < 0.05). The relative abundance of butyrate-producing Roseburia inulinivorans is evidently depleted in COVID-19 patients, while the relative abundances of Paraprevotella sp. and the probiotic Streptococcus thermophilus were increased. We further identified 30 KEGG orthology (KO) modules overrepresented, with 7 increasing and 23 decreasing modules. Notably, 15 optimal microbial markers were identified using the random forest model to have strong diagnostic potential in distinguishing COVID-19. Based on Spearman’s correlation, eight species were associated with eight clinical indices. Moreover, the increased abundance of Bacteroidetes and decreased abundance of Firmicutes were also found across clinical types of COVID-19. Our findings suggest that the alterations of gut microbiota in patients with COVID-19 may influence disease severity. Our COVID-19 classifier, which was cross-regionally verified, provides a proof of concept that a set of microbial species markers can distinguish the presence of COVID-19.

Incidence and risk factors of female urinary incontinence: a 4-year longitudinal study among 24 985 adult women in China

OBJECTIVE

To estimate the incidence of urinary incontinence (UI), including its subtypes stress UI (SUI), urgency UI (UUI) and mixed UI (MUI), and to examine risk factors for de novo SUI and UUI in Chinese women.

DESIGN

Nationwide longitudinal study.

SETTING

Six geographic regions of China.

PARTICIPANTS

Women aged ≥20 years old were included using a multistage, stratified, cluster sampling method.

METHODS

This study was conducted between May 2014 and March 2016, with follow up in 2018. Data on demographics, medical history, lifestyle and physiological and anthropometric information were collected.

MAIN OUTCOME MEASUREMENTS

Incidence, rate ratio (RR).

RESULTS

Analyses included 24 985 women (mean age 41.9 years).The follow-up response rate was 55.5%, median follow-up time was 3.7 years. The standardised incidences of UI, SUI, UUI and MUI were 21.2, 13.1, 3.0 and 5.1 per 1000 person-years, respectively. Risk factors for de novo SUI included delivery pattern (vaginal spontaneous delivery RR 2.12, 95% CI 1.62-2.78 and instrumental delivery RR 3.30, 95% CI 1.99-5.45), high body mass index (BMI) (overweight RR 1.52, 95% CI 1.33-1.74 and obesity RR 1.67, 95% CI 1.32-2.11), cigarette smoking (RR 1.54, 95% CI 1.12-2.12), chronic cough (RR 1.44, 95% CI 1.17-1.76), diabetes (RR 1.33, 95% CI 1.10-1.60) and older age (50-59 years RR 1.49, 95% CI 1.16-1.90 and 60-69 years RR 1.61, 95% CI 1.22-2.13).The risk factors significantly associated with de novo UUI were age (RR increased from 1.21, 95% CI 0.74-1.99, at 30-39 years to 6.3, 95% CI 3.85-10.30, at >70 years) and diabetes (RR 1.48, 95% CI 1.05-2.09).

CONCLUSIONS

The incidence of female UI is 21.2 per 1000 person-years in China. Delivery (vaginal spontaneous delivery, instrumental delivery), high BMI, cigarette smoking, chronic cough, diabetes and older age were risk factors.

TWEETABLE ABSTRACT

The incidence of female urinary incontinence was 21.2 per 1000 person-years in China. Delivery, BMI, diabetes and old age are risk factors.

[Evaluation on the quality of 236 National Demonstration Areas for comprehensive prevention and control of chronic diseases betweem 2017 and 2019]

Objective: To evaluate the quality of the National Demonstration Area for Comprehensive Prevention and Control of NCDs (referred to as "the Demonstration Area"). Methods: Based on the evaluation scores of the Demonstration Area field survey from 2017 to 2019, we counted the scores of each indicator, comparing the scores among indicators and regions. x±s was used to describe the scores. The 95%CI of the score was used to test the statistical difference among regions. Each score was converted into a hundred-mark system to compare the scores among indicators. Results: Of 236 Demonstration Areas, the total score was 83.5. The scores of the first-level indicator listed from high to low appeared as Integrating System of NCD Prevention and Control (92.8), Policy Perfection (90.3), Building Supportive Environment for NCD Prevention and Control (88.4), Implementation of Health Education and Health Promotion (87.4), Whole-course Management of NCDs (78.1), Innovation and Guidance (76.5), Surveillance and Evaluation (75.1). Total scores were higher in the east (259.2±18.8) comparing to the middle (243.2±15.2) or the west (245.4±19.7) regions. Conclusions: Substantial variations on the quality in the Demonstration Area existed across different regions in China. These disparities are important to the government when developing health policies and allocating resources. Whole-course Management of NCDs, Surveillance and Evaluation, and Innovation and Guidance in the Demonstration Area also needs to be improved.

Imaging orbital ferromagnetism in a moiré Chern insulator

Electrons in moiré flat band systems can spontaneously break time-reversal symmetry, giving rise to a quantized anomalous Hall effect. In this study, we use a superconducting quantum interference device to image stray magnetic fields in twisted bilayer graphene aligned to hexagonal boron nitride. We find a magnetization of several Bohr magnetons per charge carrier, demonstrating that the magnetism is primarily orbital in nature. Our measurements reveal a large change in the magnetization as the chemical potential is swept across the quantum anomalous Hall gap, consistent with the expected contribution of chiral edge states to the magnetization of an orbital Chern insulator. Mapping the spatial evolution of field-driven magnetic reversal, we find a series of reproducible micrometer-scale domains pinned to structural disorder.

Species-Specific Deamidation of RIG-I Reveals Collaborative Action between Viral and Cellular Deamidases in HSV-1 Lytic Replication

Retinoic acid-inducible gene I (RIG-I) is a sensor that recognizes cytosolic double-stranded RNA derived from microbes to induce host immune response. Viruses, such as herpesviruses, deploy diverse mechanisms to derail RIG-I-dependent innate immune defense. In this study, we discovered that mouse RIG-I is intrinsically resistant to deamidation and evasion by herpes simplex virus 1 (HSV-1). Comparative studies involving human and mouse RIG-I indicate that N495 of human RIG-I dictates species-specific deamidation by HSV-1 UL37. Remarkably, deamidation of the other site, N549, hinges on that of N495, and it is catalyzed by cellular phosphoribosylpyrophosphate amidotransferase (PPAT). Specifically, deamidation of N495 enables RIG-I to interact with PPAT, leading to subsequent deamidation of N549. Collaboration between UL37 and PPAT is required for HSV-1 to evade RIG-I-mediated antiviral immune response. This work identifies an immune regulatory role of PPAT in innate host defense and establishes a sequential deamidation event catalyzed by distinct deamidases in immune evasion.IMPORTANCE Herpesviruses are ubiquitous pathogens in human and establish lifelong persistence despite host immunity. The ability to evade host immune response is pivotal for viral persistence and pathogenesis. In this study, we investigated the evasion, mediated by deamidation, of species-specific RIG-I by herpes simplex virus 1 (HSV-1). Our findings uncovered a collaborative and sequential action between viral deamidase UL37 and a cellular glutamine amidotransferase, phosphoribosylpyrophosphate amidotransferase (PPAT), to inactivate RIG-I and mute antiviral gene expression. PPAT catalyzes the rate-limiting step of the de novo purine synthesis pathway. This work describes a new function of cellular metabolic enzymes in host defense and viral immune evasion.

A nationwide population-based survey on the prevalence and risk factors of symptomatic pelvic organ prolapse in adult women in China - a pelvic organ prolapse quantification system-based study

Objective

To determine the prevalence, risk factors and burden of symptomatic pelvic organ prolapse (POP) in adult Chinese women.

Design

A nationwide cross‐sectional study.

Setting

Six geographic regions of mainland China.

Participants

Women aged ≥20 years old were included using a multistage, stratified, cluster sampling method from February 2014 through March 2016.

Methods

We conducted a nationwide epidemiological survey. ‘Symptomatic POP’ was determined by a screening questionnaire and physical examination.

Main outcome measurements

Prevalence, odds ratio (OR).

Results

A total of 55 477 women (response rate, 92.5%; mean age, 45.1 years old) were included. The prevalence of symptomatic POP was 9.6% (95% CI 9.3–9.8%) and it increased with age in each stage (P < 0.05). Symptomatic POP‐Q stage II, which mainly involved anterior compartment prolapse, was the most common (7.52%). Minor/moderate burden of symptomatic POP was the most common, with a prevalence of 9.7% (95% CI 9.5–10.0%). The odds for each type of symptomatic POP increased with age (>50 vs 20‐29 years old in symptomatic POP‐Q stage II or higher, OR increased from 1.34 [95% CI 1.32–1.45] to 7.34 [95% CI 4.34–12.41]) and multiple vaginal deliveries (multiparous [≥3] vs nulliparous in symptomatic POP‐Q stage II or higher, OR increased from 1.91 [1.71–2.13] to 2.78 [2.13–3.64]).

Conclusions

We found a lower prevalence of symptomatic POP than that found in other surveys. The main type of symptomatic POP was anterior compartment prolapse, indicating that it should be considered first. Older age and multiple vaginal deliveries increased the odds of each type of symptomatic POP.

Tweetable abstract

The prevalence of female symptomatic pelvic organ prolapse (POP) was 9.6% in China. It is related to old age and multiple vaginal deliveries.

The prevalence of female symptomatic pelvic organ prolapse (POP) was 9.6% in China. It is related to old age and multiple vaginal deliveries.

Synovial mesenchymal stem cells effectively alleviate osteoarthritis through promoting the proliferation and differentiation of meniscus chondrocytes

OBJECTIVE

To investigate the relationship between the meniscal defect area and OA progression and explore the effect and mechanism of SMSCs cell therapy in knee osteoarthritis (OA) rat model.

MATERIALS AND METHODS

For animal experiments, knee osteoarthritis (OA) model was constructed in Sprague Dawley (SD) rats by removing the medial meniscus of the right knee. Synovial mesenchymal stem cells (SMSCs) were engrafted by injecting into the right knee cavity. For in vitro experiments, CCK-8 assay was performed to evaluate the proliferation and differentiation of BMSCs and ATDC5 cells after co-cultured with SMSCs. qRT-PCR analysis was performed to detect the expressions of chondrogenic genes in BMSCs and ATDC5 cells after co-cultured with SMSCs. Western blot analysis was conducted to detect the phosphorylations of c-Jun N-terminal kinase (JNK) and extracellular regulated protein kinases (ERK) in MAPK signaling of BMSCs and ATDC5 cells. Enzyme-linked immunosorbent assay (ELISA) was performed to detect the serum levels of interleukin (IL)-1β, IL-1β, IL-6, IL-18 and C-reactive protein (CRP).

RESULTS

Results showed that meniscus damaged area is positively correlated to serum inflammatory factor levels. In vitro study showed that the proliferation and differentiation of BMSCs and ATDC5 cells were promoted after co-cultured with SMSCs. By co-culturing with SMSCs, the MAPK signaling pathway was activated and the expression of chondrogenic markers such as aggrecan (acan), SRY-related high mobility group-box gene 9 (sox9) and Type II collagen a1 (col2a1), was up-regulated both in BMSCs and ATDC5 cells. In vivo study showed SMSCs cell therapy significantly decreased serum inflammatory factor levels and protected cartilage by upregulating the expression of chondrogenic genes of meniscus chondrocytes derived from OA rats.

CONCLUSIONS

For the first time, we found the positive correlation between meniscal defect area and OA progression and demonstrated the effect and mechanism of SMSCs cell therapy in knee osteoarthritis (OA) treatment.

Venous thromboembolic events in patients with COVID-19: a systematic review and meta-analysis

BACKGROUND

High incidence of venous thromboembolic complications in coronavirus disease 2019 (COVID-19) patients was noted recently.

OBJECTIVE

This study aimed to explore the factors associated with prevalence of venous thromboembolism (VTE) in COVID-19 patients.

METHODS

A literature search was conducted in several online databases. Fixed effects meta-analysis was performed for the factors associated with prevalence of VTE in COVID-19 patients.

RESULTS

A total of 39 studies were analysed in this analysis. The incidence of pulmonary embolism and VTE in severe COVID-19 patients were 17% (95% CI, 13-21%) and 42% (95% CI, 25-60%), respectively. VTE were more common among individuals with COVID-19 of advance age. Male COVID-19 patients are more likely to experience VTE. Higher levels of white blood cell (WBC; WMD = 1.34 × 109/L; 95% CI, 0.84-1.84 × 109/L), D-dimer (WMD = 4.21 μg/ml; 95% CI, 3.77-4.66 μg/ml), activated partial thromboplastin time (APTT; WMD = 2.03 s; 95% CI, 0.83-3.24 s), fibrinogen (WMD = 0.49 μg/ml; 95% CI, 0.18-0.79 g/L) and C-reactive protein (CRP; WMD = 21.89 mg/L; 95% CI, 11.44-32.34 mg/L) were commonly noted in COVID-19 patients with VTE. Patients with lower level of lymphocyte (WMD = -0.15 × 109/L; 95% CI, -0.23--0.07 × 109/L) was at high risk of developing VTE. The incidence of severe condition (OR = 2.66; 95% CI, 1.95-3.62) was more likely to occur among COVID-19 patients who developed VTE.

CONCLUSION

VTE is a common complication in severe COVID-19 patients and thromboembolic events are also associated with adverse outcomes.

Modalities and Mechanisms of Treatment for Coronavirus Disease 2019

Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is spreading rapidly throughout the world. Although COVID-19 has a relatively low case severity rate compared to SARS and Middle East Respiratory syndrome it is a major public concern because of its rapid spread and devastating impact on the global economy. Scientists and clinicians are urgently trying to identify drugs to combat the virus with hundreds of clinical trials underway. Current treatments could be divided into two major part: anti-viral agents and host system modulatory agents. On one hand, anti-viral agents focus on virus infection process. Umifenovir blocks virus recognizing host and entry. Remdesivir inhibits virus replication. Chloroquine and hydroxychloroquine involve preventing the whole infection process, including virus transcription and release. On the other hand, host system modulatory agents are associated with regulating the imbalanced inflammatory reaction and biased immune system. Corticosteroid is believed to be commonly used for repressing hyper-inflammation, which is one of the major pathologic mechanisms of COVID-19. Convalescent plasma and neutralizing antibodies provide essential elements for host immune system and create passive immunization. Thrombotic events are at high incidence in COVID-19 patients, thus anti-platelet and anti-coagulation are crucial, as well. Here, we summarized these current or reproposed agents to better understand the mechanisms of agents and give an update of present research situation.

Epigallocatechin-3-gallate, an active ingredient of Traditional Chinese Medicines, inhibits the 3CLpro activity of SARS-CoV-2

SARS-CoV-2 is the etiological agent responsible for the ongoing pandemic of coronavirus disease 2019 (COVID-19). The main protease of SARS-CoV-2, 3CLpro, is an attractive target for antiviral inhibitors due to its indispensable role in viral replication and gene expression of viral proteins. The search of compounds that can effectively inhibit the crucial activity of 3CLpro, which results to interference of the virus life cycle, is now widely pursued. Here, we report that epigallocatechin-3-gallate (EGCG), an active ingredient of Chinese herbal medicine (CHM), is a potent inhibitor of 3CLpro with half-maximum inhibitory concentration (IC50) of 0.874 ± 0.005 μM. In the study, we retrospectively analyzed the clinical data of 123 cases of COVID-19 patients, and found three effective Traditional Chinese Medicines (TCM) prescriptions. Multiple strategies were performed to screen potent inhibitors of SARS-CoV-2 3CLpro from the active ingredients of TCMs, including network pharmacology, molecular docking, surface plasmon resonance (SPR) binding assay and fluorescence resonance energy transfer (FRET)-based inhibition assay. The SPR assay showed good interaction between EGCG and 3CLpro with KD ~6.17 μM, suggesting a relatively high affinity of EGCG with SARS-CoV-2 3CLpro. Our results provide critical insights into the mechanism of action of EGCG as a potential therapeutic agent against COVID-19.

Comparative Transcriptome Analysis Reveals the Intensive Early Stage Responses of Host Cells to SARS-CoV-2 Infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a widespread outbreak of highly pathogenic coronavirus disease 2019 (COVID-19). It is therefore important and timely to characterize interactions between the virus and host cell at the molecular level to understand its disease pathogenesis. To gain insights, we performed high-throughput sequencing that generated time-series data simultaneously for bioinformatics analysis of virus genomes and host transcriptomes implicated in SARS-CoV-2 infection. Our analysis results showed that the rapid growth of the virus was accompanied by an early intensive response of host genes. We also systematically compared the molecular footprints of the host cells in response to SARS-CoV-2, SARS-CoV, and Middle East respiratory syndrome coronavirus (MERS-CoV). Upon infection, SARS-CoV-2 induced hundreds of up-regulated host genes hallmarked by a significant cytokine production, followed by virus-specific host antiviral responses. While the cytokine and antiviral responses triggered by SARS-CoV and MERS-CoV were only observed during the late stage of infection, the host antiviral responses during the SARS-CoV-2 infection were gradually enhanced lagging behind the production of cytokine. The early rapid host responses were potentially attributed to the high efficiency of SARS-CoV-2 entry into host cells, underscored by evidence of a remarkably up-regulated gene expression of TPRMSS2 soon after infection. Taken together, our findings provide novel molecular insights into the mechanisms underlying the infectivity and pathogenicity of SARS-CoV-2.

Evaluation of current medical approaches for COVID-19: a systematic review and meta-analysis

BACKGROUND

Because of the lack of vaccination, it is urgent to find effective antiviral agents for COVID-19 treatment.

METHOD

Online databases were searched for articles published before or on 22 June 2020. Studies reporting the effectiveness and safety of antiviral agents for COVID-19 were analysed.

RESULTS

A total of 42 studies were included in this analysis. Hydroxychloroquine (HCQ) was not associated with the incidence of death (risk ratio (RR)=1.08; 95% CI 0.81 to 1.44) and severe cases (RR=1.05; 95% CI 0.61 to 1.81). Patients treated with HCQ obtained few benefits with respect to the clearance of viral RNA and were more likely to have adverse reactions. HCQ treatment could shorten the body temperature recovery time (weighted mean difference = -1.04; 95% CI -1.64 to -0.45). Lopinavir/ritonavir (LPV/r) (RR=0.90; 95% CI 0.76 to 1.07) and Arbidol (RR=1.09; 95% CI 0.92 to 1.29) were not associated with the negative conversion rate. Integrative Chinese-Western medicine alleviated clinical symptoms and decreased the incidence of severe cases (RR=0.38; 95% CI 0.25 to 0.59). Remdesivir treatment reduced the 14-day mortality rate of patients with severe COVID-19 (RR=0.64; 95% CI 0.44 to 0.94). Convalescent plasma (CP) tended to increase the negative conversion rate (RR=2.47; 95% CI 1.70 to 3.57).

CONCLUSION

HCQ, LPV/r and Arbidol bring little benefit in COVID-19 treatment. Integrative Chinese-Western medicine improved the clinical symptoms of patients with COVID-19. Remdesivir and CP might be the potential treatments for patients with severe COVID-19. However, large-scale clinical randomised trials are needed to validate our conclusions.

Multi-organ Dysfunction in Patients with COVID-19: A Systematic Review and Meta-analysis

This study aimed to provide systematic evidence for the association between multiorgan dysfunction and COVID-19 development. Several online databases were searched for articles published until May 13, 2020. Two investigators independently selected trials, extracted data, and evaluated the quality of individual trials. Single-arm meta-analysis was performed to summarize the clinical features of confirmed COVID-19 patients. Fixed effects meta-analysis was performed for clinically relevant parameters that were closely related to the patients' various organ functions. A total of 73 studies, including 171,108 patients, were included in this analysis. The overall incidence of severe COVID-19 and mortality were 24% (95% confidence interval [CI], 20%-28%) and 2% (95% CI, 1%-3%), respectively. Patients with hypertension (odds ratio [OR] = 2.40; 95% CI, 2.08-2.78), cardiovascular disease (CVD) (OR = 3.54; 95% CI, 2.68-4.68), chronic obstructive pulmonary disease (COPD) (OR=3.70; 95% CI, 2.93-4.68), chronic liver disease (CLD) (OR=1.48; 95% CI, 1.09-2.01), chronic kidney disease (CKD) (OR = 1.84; 95% CI, 1.47-2.30), chronic cerebrovascular diseases (OR = 2.53; 95% CI, 1.84-3.49) and chronic gastrointestinal (GI) disease (OR = 2.13; 95% CI, 1.12-4.05) were more likely to develop severe COVID-19. Increased levels of lactate dehydrogenase (LDH), creatine kinase (CK), high-sensitivity cardiac troponin I (hs-cTnI), myoglobin, creatinine, urea, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin were highly associated with severe COVID-19. The incidence of acute organ injuries, including acute cardiac injury (ACI); (OR = 11.87; 95% CI, 7.64-18.46), acute kidney injury (AKI); (OR=10.25; 95% CI, 7.60-13.84), acute respiratory distress syndrome (ARDS); (OR=27.66; 95% CI, 18.58-41.18), and acute cerebrovascular diseases (OR=9.22; 95% CI, 1.61-52.72) was more common in patients with severe COVID-19 than in patients with non-severe COVID-19. Patients with a history of organ dysfunction are more susceptible to severe conditions. COVID-19 can aggravate an acute multiorgan injury.

Zika virus-spread, epidemiology, genome, transmission cycle, clinical manifestation, associated challenges, vaccine and antiviral drug development

Zika Virus (ZIKV) is a Flavivirus transmitted primarily via the bite of infected Aedes aegypti mosquitoes. Globally, 87 countries and territories have recorded autochthonous mosquito-borne transmission of ZIKV as at July 2019 and distributed across four of the six WHO Regions. Outbreaks of ZIKV infection peaked in 2016 and declined substantially throughout 2017 and 2018 in the Americas region. There is the likely risk for ZIKV to spread to more countries. There is also the potential for the re-emergence of ZIKV in all places with prior reports of the virus transmission. The current status of ZIKV transmission and spread is, however, a global health threat, and from the aforementioned, has the potential to re-emerge as an epidemic. This review summarizes the past and present spread of ZIKV outbreak-2007-2019, the genome, transmission cycle, clinical manifestations, vaccine and antiviral drug advancement.

Cell membrane proteins with high N-glycosylation, high expression and multiple interaction partners are preferred by mammalian viruses as receptors

Motivation

Receptor mediated entry is the first step for viral infection. However, the question of how viruses select receptors remains unanswered.

Results

Here, by manually curating a high-quality database of 268 pairs of mammalian virus–host receptor interaction, which included 128 unique viral species or sub-species and 119 virus receptors, we found the viral receptors are structurally and functionally diverse, yet they had several common features when compared to other cell membrane proteins: more protein domains, higher level of N-glycosylation, higher ratio of self-interaction and more interaction partners, and higher expression in most tissues of the host. This study could deepen our understanding of virus–receptor interaction.

Availability and implementation

The database of mammalian virus–host receptor interaction is available at http://www.computationalbiology.cn: 5000/viralReceptor.

Supplementary information

Supplementary data are available at Bioinformatics online.

DNA methylation modifier LSH inhibits p53 ubiquitination and transactivates p53 to promote lipid metabolism

BACKGROUND

The stability of p53 is mainly controlled by ubiquitin-dependent degradation, which is triggered by the E3 ubiquitin ligase MDM2. The chromatin modifier lymphoid-specific helicase (LSH) is essential for DNA methylation and cancer progression as a transcriptional repressor. The potential interplay between chromatin modifiers and transcription factors remains largely unknown.

RESULTS

Here, we present data suggesting that LSH regulates p53 in cis through two pathways: prevention proteasomal degradation through its deubiquitination, which is achieved by reducing the lysine 11-linked, lysine 48-linked polyubiquitin chains (K11 and K48) on p53; and revival of the transcriptional activity of p53 by forming a complex with PKM2 (pyruvate kinase 2). Furthermore, we confirmed that the LSH-PKM2 interaction occurred at the intersubunit interface region of the PKM2 C-terminal region and the coiled-coil domains (CC) and ATP-binding domains of LSH, and this interaction regulated p53-mediated transactivation in cis in lipid metabolism, especially lipid catabolism.

CONCLUSION

These findings suggest that LSH is a novel regulator of p53 through the proteasomal pathway, thereby providing an alternative mechanism of p53 involvement in lipid metabolism in cancer.

Protein interactome of the deamidase phosphoribosylformylglycinamidine synthetase (PFAS) by LC-MS/MS

Phosphoribosylformylglycinamidine synthase (PFAS) is an essential enzyme in de novo synthesis of purine. Previously, PFAS has been reported to modulate RIG-I activation during viral infection via deamidation. In this study, we sought to identify potential substrates that PFAS can deamidate. Flag-PFAS was transfected into HEK-293T cells and PFAS associated proteins were purified with anti-Flag M2 magnetic beads. PFAS associated proteins were identified using mass spectrometry and were analyzed using bioinformatics tools including KEGG pathway analysis, gene ontology annotation, and protein interaction network analysis. A total of 441 proteins is suggested to potentially interact with PFAS. Of this number, 12 were previously identified and 429 are newly identified. The interactions of PFAS with CAD, CCT2, PRDX1, and PHGDH were confirmed by co-immunoprecipitation and western blotting. This study is first to report the interaction of PFAS with several proteins which play physiological roles in tumor development including CAD, CCT2, PRDX1, and PHGDH. Furthermore, we show here that PFAS is able to deamidate PHGDH, and induce other posttranslational modification into CAD, CCT2 and PRDX1. The present data provide insight on the biological function of PFAS. Further study to explore the role of these protein interactions in tumorigenesis and other diseases is recommended.

Effects of oat protein supplementation on skeletal muscle damage, inflammation and performance recovery following downhill running in untrained collegiate men

The positive influence of animal-based protein supplementation during muscle-damaging exercise has been widely studied. However, the effects of plant-based proteins remain unclear and require further clarification. This study investigated the protective role of oat protein against exercise induced muscle damage (EIMD), subsequent inflammation, and loss of performance induced by downhill running. Subjects consumed either oat protein (25 g protein) or a placebo for 14 days prior to a downhill running test and then for 4 days thereafter. Treatments with oat protein for 19 days markedly alleviated eccentric exercise induced skeletal muscle soreness, and reduced the elevation of plasma IL-6 concentrations and serum creatine kinase, myoglobin and C reactive protein contents. In addition, oat protein supplementation significantly inhibited limb edema following damaging exercise, and the adverse effects on muscle strength, knee-joint range of motion, and vertical jump performance were lessened. Furthermore, the administration of oat protein facilitated recovery from exhaustive downhill running in this study. These findings demonstrated that oat protein supplementation has the potential to alleviate the negative effects of eccentric exercise in untrained young males.

An epidemiologic study of pelvic organ prolapse in postmenopausal women: a population-based sample in China

OBJECTIVE

This study aimed to assess the prevalence and factors associated with symptomatic pelvic organ prolapse (POP) in a representative sample of postmenopausal Chinese women.

METHODS

A total of 20,008 postmenopausal Chinese women were recruited to this cross-sectional study between February 2014 and March 2016. The prevalence of symptomatic POP, defined as any stage II or higher POP resulting in symptoms, was assessed using questionnaires and physical examinations. Multivariable logistic regression was used to assess factors associated with symptomatic POP.

RESULTS

Among all women with natural menopause included in the study (mean age =61.98 ± 10.62 years), 2962 of 20,008 women (14.80%, 95% confidence interval [CI] 14.3-15.3%) had symptomatic POP. In the multivariate analysis, women were more likely to have symptomatic POP if aged 50-59 years (adjusted odds ratio [AOR] 1.322, 95% CI 1.123-1.560), 60-69 years (AOR 1.603, 95% CI 1.352-1.907), or above 70 years (AOR 1.824, 95% CI 1.158-2.197), compared with women aged 40-49 years. Having delivered two times (AOR 1.145, 95% CI 1.105-1.292) or three or more times (AOR 1.384, 95% CI 1.214-1.578) was significantly associated with symptomatic POP. Compared with normal weight women, overweight women (AOR 1.365, 95% CI 1.247-1.494) and obese women (AOR 1.548, 95% CI 1.344-1.780) were more likely to have POP. Living in an urban area, smoking, alcohol consumption, cough, constipation, mental labor, physical disease, and gynecological diseases were also associated with symptomatic POP.

CONCLUSIONS

Symptomatic POP affects nearly 15% of postmenopausal women in China. The prevalence of symptomatic POP increases significantly with age, body mass index, and parity.

Diagnostic guidelines for the histological particle algorithm in the periprosthetic neo-synovial tissue

BACKGROUND

The identification of implant wear particles and non-implant related particles and the characterization of the inflammatory responses in the periprosthetic neo-synovial membrane, bone, and the synovial-like interface membrane (SLIM) play an important role for the evaluation of clinical outcome, correlation with radiological and implant retrieval studies, and understanding of the biological pathways contributing to implant failures in joint arthroplasty. The purpose of this study is to present a comprehensive histological particle algorithm (HPA) as a practical guide to particle identification at routine light microscopy examination.

METHODS

The cases used for particle analysis were selected retrospectively from the archives of two institutions and were representative of the implant wear and non-implant related particle spectrum. All particle categories were described according to their size, shape, colour and properties observed at light microscopy, under polarized light, and after histochemical stains when necessary. A unified range of particle size, defined as a measure of length only, is proposed for the wear particles with five classes for polyethylene (PE) particles and four classes for conventional and corrosion metallic particles and ceramic particles.

RESULTS

All implant wear and non-implant related particles were described and illustrated in detail by category. A particle scoring system for the periprosthetic tissue/SLIM is proposed as follows: 1) Wear particle identification at light microscopy with a two-step analysis at low (× 25, × 40, and × 100) and high magnification (× 200 and × 400); 2) Identification of the predominant wear particle type with size determination; 3) The presence of non-implant related endogenous and/or foreign particles. A guide for a comprehensive pathology report is also provided with sections for macroscopic and microscopic description, and diagnosis.

CONCLUSIONS

The HPA should be considered a standard for the histological analysis of periprosthetic neo-synovial membrane, bone, and SLIM. It provides a basic, standardized tool for the identification of implant wear and non-implant related particles at routine light microscopy examination and aims at reducing intra-observer and inter-observer variability to provide a common platform for multicentric implant retrieval/radiological/histological studies and valuable data for the risk assessment of implant performance for regional and national implant registries and government agencies.

Mild Hypothermia Protects Renal Function in Ischemia-reperfusion Kidney: An Experimental Study in Mice

Mild hypothermia reduces the damage caused by hypoxia and oxidative stress, but how this happens is not very clear. Mice were anesthetized and their core body temperature was maintained at 38 ± 0.5°C and 32 ± 0.5°C. The renal artery and renal veins were blocked for 35 minutes and reperfusion was performed. Twenty-four hours later, serum was obtained to detect the concentrations of creatinine. The expression of CIRP, TRX, Bcl-2, and Bax were detected in tissue samples using Western blot. Apoptosis was measured using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and the apoptosis rates were calculated. SOD and MDA were detected to determine the extent of oxidative damage in different groups. The concentration of creatinine in the NC group was 2.11 ± 0.39 mg/dL. Compared to the IR group, the concentration of creatinine decreased in MH+IR group and showed a significant statistical difference (8.74 ± 1.38 mg/dL vs 15.36 ± 2.13 mg/dL, P < .01); the apoptosis rate also decreased with statistical significance (15.02 ± 1.45% vs 37.02 ± 5.70%, P < .01). Compared to the IR group, the expression of CIRP, TRX, and the Bcl-2/Bax ratio significantly increased in the MH+IR group. The SOD activity in the MH+IR group increased (26.90 ± 4.41 U/mgprot vs 16.85 ± 2.41 U/mgprot, P < .05) and the MDA level decreased (0.76 ± 0.18 nmol/mgprot vs 1.37 ± 0.32 nmol/mgprot, P < .05) compared to those of the IR group. Mild hypothermia protects mice kidneys from ischemia-reperfusion damage by reducing oxidative stress injury and apoptosis.

Species-Specific Deamidation of cGAS by Herpes Simplex Virus UL37 Protein Facilitates Viral Replication

Herpes simplex virus 1 (HSV-1) establishes infections in humans and mice, but some non-human primates exhibit resistance via unknown mechanisms. Innate immune recognition pathways are highly conserved but are pivotal in determining susceptibility to DNA virus infections. We report that variation of a single amino acid residue in the innate immune sensor cGAS determines species-specific inactivation by HSV-1. The HSV-1 UL37 tegument protein deamidates human and mouse cGAS. Deamidation impairs the ability of cGAS to catalyze cGAMP synthesis, which activates innate immunity. HSV-1 with deamidase-deficient UL37 promotes robust antiviral responses and is attenuated in mice in a cGAS- and STING-dependent manner. Mutational analyses identified a single asparagine in human and mouse cGAS that is not conserved in many non-human primates. This residue underpins UL37-mediated cGAS deamidation and species permissiveness of HSV-1. Thus, HSV-1 mediates cGAS deamidation for immune evasion and exploits species sequence variation to disarm host defenses.

Myocardial ischaemia reperfusion injury: the challenge of translating ischaemic and anaesthetic protection from animal models to humans

Myocardial ischaemia reperfusion injury is the leading cause of death in patients with cardiovascular disease. Interventions such as ischaemic pre and postconditioning protect against myocardial ischaemia reperfusion injury. Certain anaesthesia drugs and opioids can produce the same effects, which led to an initial flurry of excitement given the extensive use of these drugs in surgery. The underlying mechanisms have since been extensively studied in experimental animal models but attempts to translate these findings to clinical settings have resulted in contradictory results. There are a number of reasons for this such as dose response, the intensity of the ischaemic stimulus applied, the duration of ischaemia and lost or diminished cardioprotection in common co-morbidities such as diabetes and senescence. This review focuses on current knowledge regarding myocardial ischaemia reperfusion injury and cardioprotective interventions both in experimental animal studies and in clinical trials.

β-catenin regulates IRF3-mediated innate immune signalling in colorectal cancer

OBJECTIVE

β-catenin is one of the most critical oncogenes associated with many kinds of human cancers, especially in the human CRC. Innate immunity recognizes tumour derived damage-associated molecular patterns (DAMPs) and primes the anti-tumour adaptive responses. While the function of β-catenin in CRC tumourigenesis is well established, its impact on innate immune evasion is largely unknown. The aim of this study is to characterize the role of β-catenin in inhibiting RIG-I-like receptor (RLR)-mediated IFN-β signalling in colorectal cancer.

MATERIALS AND METHODS

Immunohistochemical staining and western blotting were conducted to study the expression of β-catenin, IRF3 and phospho-IRF3 (p-IRF3) in CRC samples and cell lines. Plaque assay determining virus replication was performed to assess the regulation of β-catenin on IFN-β signalling. The inhibition of β-catenin on RLR-mediated IFN-β signalling was further studied by real-time analyses and reporter assays in the context of lentiviral-mediated β-catenin stably knocking down. Lastly, co-immunoprecipitation and nuclear fractionation assay were conducted to monitor the interaction between β-catenin and IRF3.

RESULTS

We found that high expression of β-catenin positively correlated with the expression of IRF3 in CRC cells. Overexpression of β-catenin increased the viral replication. Conversely knocking down of β-catenin inhibited viral replication. Furthermore, our data demonstrated that β-catenin could inhibit the expression of IFN-β and interferon-stimulated gene 56 (ISG56). Mechanistically, we found that β-catenin interacted with IRF3 and blocked its nuclear translocation.

CONCLUSION

Our study reveals an unprecedented role of β-catenin in enabling innate immune evasion in CRC.

A potential strategy for counteracting age-related sarcopenia: preliminary evidence of combined exercise training and leucine supplementation

Previous research has demonstrated the positive effects of concurrent/combined aerobic and resistance exercise or leucine supplementation on skeletal muscle protein synthesis (MPS) and hypertrophy in aging organisms. However, the effects of a multimodal intervention which combines both aerobic and resistance exercise and leucine supplementation has not been fully elucidated. Eighteen month old and 2 month old C57BL/6 mice were assigned to aging control (AC, n = 8), aging and multimodal intervention (AMI, n = 8) and young control (YC, n = 8). Mice in the YC and AC groups were fed an alanine-rich diet (3.4%), and mice in the AMI group received an isonitrogenous leucine-supplemented (5%) diet in combination with combined aerobic (30 minutes swimming) and resistance exercise training (incremental jumping submersed in water with overload corresponding to 40%-50% body weight) for a total of 4 weeks. The gastrocnemius muscles were dissected for western blotting detection (signaling proteins involved in MPS) and the ex vivo determination of protein synthesis and protein content. The muscle strength of the hind limbs was measured pre-experiment and repeated once per week on Sunday for 4 weeks. Mice in the AC and AMI groups showed lower ex vivo protein synthesis, protein content, expression of signaling proteins involved in MPS, maximal grip strength but higher plasma cortisol compared with the YC group post intervention. When compared to AC mice, the multimodal treatment led to lower activity of Sestrin2, higher expression of PI3K III and the phosphorylation of mTOR, p70S6K and 4E-BP1, as well as higher plasma leucine, wet gastrocnemius muscle weight and muscle weight to body weight ratio. Furthermore, the multimodal intervention induced more pronounced anabolic response such as higher ex vivo protein synthesis rate, total protein content, and myofibrillar fractions in gastrocnemius muscle, and greater maximum grip strength. The present research shows that a multimodal intervention including combined both aerobic and resistance exercise training and 5% leucine supplementation has the potential to maintain skeletal muscle protein synthesis and attenuate losses in muscular strength during the aging process.