Molecular Classification of Endometrial Endometrioid Carcinoma With Microcystic Elongated and Fragmented Pattern

The studies on the molecular classification of endometrioid carcinoma (EC) with microcystic, elongated, and fragmented (MELF) pattern invasion are limited. In this study, 77 cases of ECs with MELF patterns in Chinese women were collected. The molecular classification of the fifth edition of the World Health Organization was used to classify the molecular subtypes using immunohistochemistry staining (mismatch repair [MMR]-immunohistochemistry: MSH2, MSH6, MLH1, and PMS2; p53) and Sanger sequencing targeted POLE . The results showed that the prevalence of the 4 molecular subtypes in EC with MELF pattern was 6.5% (5/77) for POLE mutation, 20.8% (16/77) for MMR deficient, 11.7% (9/77) for p53-mutant, and 61.0% (47/77) for no specific molecular profile. The clinicopathological characteristics of each subtype were compared. The p53-mutant and no specific molecular profile subgroups were associated with higher International Federation of Gynecology and Obstetrics stage and International Federation of Gynecology and Obstetrics grade, deeper myometrial invasion, lymphovascular space invasion, lymph node metastasis, and absence of tumor-infiltrating lymphocytes, whereas the POLE mutation and MMR deficient subgroups were associated with lower aggressive features and prominent tumor-infiltrating lymphocytes. Progression-free survival showed that the p53-mutant and no specific molecular profile subgroups had a poorer prognosis than the POLE mutation and MMR deficient subgroups. However, lymph node metastasis was an independent factor associated with a higher risk of disease recurrence in multivariate analysis. In conclusion, ECs with MELF patterns can be divided into 4 molecular subtypes with discrepancies in aggressive clinicopathological characteristics and tumor-infiltrating lymphocytes. Molecular classification has clinical significance in a morpho-molecular approach for ECs with MELF patterns.

[Progress in research of epidemiology of relapsing fever and prevention and control measures]

Relapsing fever, caused by Borreliae of the relapsing fever groups, is an infectious disease, which would cause spirochaetaemia and repeated fever in human. To comprehensively understand the classification and distribution of relapsing fever, as well as correlated factors, this paper summarizes the progress in research of epidemiology of relapsing fever in the world, and suggests prevention and control measures. The disease is heterogenous and can be divided into three groups according to vectors, i.e. tick-borne relapsing fever, louse-borne relapsing fever and the avian relapsing fever. Tick borne relapsing fever can be further divided into two types: soft tick transmission and hard tick transmission. Soft tick-borne relapsing fever generally has obvious geographical distribution characteristics, while hard tick-borne relapsing fever is widely distributed all over the world. Louse-borne relapsing fever, also known as epidemic forms of relapsing fever, is caused by body lice, and the incidence is usually associated with war, famine, refugees and poor sanitation. The prevention and control of relapsing fever should be based on local conditions.

Identification of SIRT3 as an eraser of H4K16la

Lysine lactylation (Kla) is a novel histone post-translational modification discovered in late 2019. Later, HDAC1-3, were identified as the robust Kla erasers. While the Sirtuin family proteins showed weak eraser activities toward Kla, as reported. However, the catalytic mechanisms and physiological functions of HDACs and Sirtuins are not identical. In this study, we observed that SIRT3 exhibits a higher eraser activity against the H4K16la site than the other human Sirtuins. Crystal structures revealed the detailed binding mechanisms between lactyl-lysine peptides and SIRT3. Furthermore, a chemical probe, p-H4K16laAlk, was developed to capture potential Kla erasers from cell lysates. SIRT3 was captured by this probe and detected via proteomic analysis. And another chemical probe, p-H4K16la-NBD, was developed to detect the eraser-Kla delactylation processes directly via fluorescence indication. Our findings and chemical probes provide new directions for further investigating Kla and its roles in gene transcription regulation.

Regioselective stilbene O-methylations in Saccharinae grasses

O-Methylated stilbenes are prominent nutraceuticals but rarely produced by crops. Here, the inherent ability of two Saccharinae grasses to produce regioselectively O-methylated stilbenes is reported. A stilbene O-methyltransferase, SbSOMT, is first shown to be indispensable for pathogen-inducible pterostilbene (3,5-bis-O-methylated) biosynthesis in sorghum (Sorghum bicolor). Phylogenetic analysis indicates the recruitment of genus-specific SOMTs from canonical caffeic acid O-methyltransferases (COMTs) after the divergence of Sorghum spp. from Saccharum spp. In recombinant enzyme assays, SbSOMT and COMTs regioselectively catalyze O-methylation of stilbene A-ring and B-ring respectively. Subsequently, SOMT-stilbene crystal structures are presented. Whilst SbSOMT shows global structural resemblance to SbCOMT, molecular characterizations illustrate two hydrophobic residues (Ile144/Phe337) crucial for substrate binding orientation leading to 3,5-bis-O-methylations in the A-ring. In contrast, the equivalent residues (Asn128/Asn323) in SbCOMT facilitate an opposite orientation that favors 3'-O-methylation in the B-ring. Consistently, a highly-conserved COMT is likely involved in isorhapontigenin (3'-O-methylated) formation in wounded wild sugarcane (Saccharum spontaneum). Altogether, our work reveals the potential of Saccharinae grasses as a source of O-methylated stilbenes, and rationalize the regioselectivity of SOMT activities for bioengineering of O-methylated stilbenes.

Risk prediction of second primary malignancies in primary colorectal neuroendocrine neoplasms patients: a population-based study

PURPOSE

In this study, we aimed to identify risk factors for developing second primary malignancies (SPMs) in colorectal neuroendocrine neoplasms (NENs) patients and develop a competing-risk nomogram to predict SPMs' probabilities quantitatively.

METHODS

Patients with colorectal NENs were retrospectively collected from the Surveillance, Epidemiology, and End Results (SEER) database during 2000-2013. Potential risk factors for SPMs' occurrence in colorectal NENs' patients were identified by the Fine and Gray's proportional sub-distribution hazards model. Then, a competing-risk nomogram was constructed to quantify SPMs' probabilities. The discriminative abilities and calibrations of this competing-risk nomogram were assessed by the area under the receiver-operating characteristic (ROC) curves (AUC) and calibration curves.

RESULTS

We identified 11,017 colorectal NENs' patients, and randomly divided them into training (n = 7711 patients) and validation (n = 3306 patients) cohorts. In the whole cohort, 12.4% patients (n = 1369) had developed SPMs during the maximum follow-up of approximately 19 years (median 8.9 years). Sex, age, race, primary tumor location, and chemotherapy were identified as risk factors for SPMs' occurrence in colorectal NENs' patients. Such factors were selected to develop a competing-risk nomogram and showed excellent predictive ability for SPMs' occurrence (the 3-, 5-, and 10-year AUC values were 0.631, 0.632, and 0.629 in the training cohort and 0.665, 0.639, 0.624 in the validation cohort, respectively).

CONCLUSIONS

This research identified risk factors for SPMs' occurrence in colorectal NENs' patients. Competing-risk nomogram was constructed and proved to have good performance.

Universal Strategy to Develop Fluorogenic Probes for Lysine Deacylase/Demethylase Activity and Application in Discriminating Demethylation States

Dynamically controlling the post-translational modification of the ε-amino groups of lysine residues is critical for regulating many cellular events. Increasing studies have revealed that many important diseases, including cancer and neurological disorders, are associated with the malfunction of lysine deacylases and demethylases. Developing fluorescent probes that are capable of detecting lysine deacylase and demethylase activity is highly useful for interrogating their roles in epigenetic regulation and diseases. Due to the distinct substrate recognition of these epigenetic eraser enzymes, designing a universal strategy for detecting their activity poses substantial difficulty. Moreover, designing activity-based probes for differentiating their demethylation states is even more challenging and still remains largely unexplored. Herein, we report a universal strategy to construct probes that can detect the enzymatic activity of epigenetic "erasers" through NBD-based long-distance intramolecular reactions. The probes can be easily prepared by installing the O-NBD group at the C-terminal residue of specific peptide substrates by click chemistry. Based on this strategy, detecting the activity of lysine deacetylase, desuccinylase, or demethylase with superior sensitivity and selectivity has been successfully achieved through single-step probe development. Furthermore, the demethylase probe based on this strategy is capable of distinguishing different demethylation states by both absorption and fluorescence lifetime readout. We envision that these newly developed probes will provide powerful tools to facilitate drug discovery in epigenetics in the future.

linc00958/miR-185-5p/RSF-1 modulates cisplatin resistance and angiogenesis through AKT1/GSK3β/VEGFA pathway in cervical cancer

BACKGROUND

Chemoresistance is one of the major obstacles that lead to poor prognosis in cervical cancer. linc00958 was reported to be an oncogene in cervical cancer. However, its role in mediating chemoresistance remains to be revealed.

PURPOSE

To explore the regulatory mechanisms of linc00958 in cisplatin-resistant cervical cancer cells and further validate in xenograft mice.

METHODS

Online bioinformatic tools were used to conduct the pre-investigation of linc00958/miR-185-5p/RSF-1 and predict the associations between RSF-1 and AKT1/GSK3β/VEGFA in cervical cancer. RT-qPCR measured the RNA expression levels of linc00958/miR-185-5p/RSF-1 in SiHa and SiHa/DDP. Cell survival rates were evaluated by CCK8 methods after cells were exposed to differential concentrations of DDP. Dual-luciferase reporter methods were used to measure luciferase activity. Western blot measured RSF-1 protein and phosphorylated changes of AKT1/GSK3β. Immunofluorescence was employed to observe VEGFA secretion in vitro. Tube formation was applied to evaluate the in-vitro changes of angiogenesis. The SiHa/DDP cells stably transfected with pLKO-sh-NC or pLKO-sh-linc00958 plasmids, were injected into mice, establishing xenograft models. The changes in mice weight and tumor volumes were recorded. H&E staining and Immunohistochemistry (IHC) method was further performed.

RESULTS

linc00958 expression was higher in SiHa/DDP cells. High linc00958 expression was associated with low overall survival. In SiHa/DDP cells linc00958/miR-185-5p/RSF-1 axis inhibited the cellular resistance to cisplatin and suppressed VEGFA and the tube formation through AKT1/GSK3β/VEGFA pathway. The knockdown of linc00958 inhibited RSF-1 and Ki67, curbing tumor growth; it also inhibited VEGFA and CD34, decreasing angiogenesis in mice.

CONCLUSION

linc00958/miR-185-5p/RSF-1 modulates cisplatin resistance and angiogenesis through AKT1/GSK3β/VEGFA pathway in cervical cancer.

Downregulation of SOX21-AS1 alleviated cisplatin resistance in cervical cancer through Epithelial-messenchymal transition (EMT) inhibition

Cisplatin is widely used in chemotherapies in cervical cancer (CC). Nevertheless, drug resistance in cancer patients poses a major threat to efficacy of treatment. To explore the underlying modulatory mechanism of SOX21-AS1 in cisplatin resistance in CC cell and mice models，Gepia database was referred for SOX21-AS1 expression in cancer tissues and normal ones. RT-qPCR was used to measure the differential expression of SOX21-AS1 in parental Siha cells and cisplatin-resistant Siha/DDP cells. Luciferase reporter gene assays were conducted to verify putative bindings between SOX21-AS1 and miR-9-3p. Western blot method was employed to evaluate the changes in cleaved-caspase 7 protein expression. Cisplatin resistance was evaluated in each transfected group using CCK8 method after cells were exposed to cisplatin (0,7.5,15,30,60,120, 240ug/ml) for 24h. Flow cytometry method was used to measure the apoptosis rates. Cell migration and invasion were measured using Transwell assays. Immunofluorescence method was applied to observe EMT markers including E-cadherin, Snail, MMP3 and MMP9. Siha/DDP cell groups stably transfected with sh-NC and sh- SOX21-AS1 were injected through tail vein of Balb/C mice. Lung tissue sections were used for HE staining and IHC analysis. SOX1-AS1 expression was higher in cancer tissues than normal ones and was also higher in Siha/DDP rather than Siha cells. SOX21-AS1 was targeted by miR-9-3p in CC cells. Downregulation of SOX21-AS1 or overexpression of miR-9-3p inhibited cisplatin resistance in Siha/DDP cells and reduced cell invasion and migration and attenuated EMT progression. In vivo, the SOX21-AS1 knockdown led to less severe lung metastasis. Downregulation of SOX21-AS1 alleviated cisplatin resistance in cervical cancer through EMT inhibition.

Esophageal cancer-related gene 4 and solid tumors: a brief literature review

Esophageal cancer-related gene 4 (ECRG4) plays key roles in various malignancies, including lung cancer, prostate cancer, esophageal cancer, and breast cancer, and has potential applications in the early diagnosis, prevention, treatment, and prognosis of cancer. However, the mechanisms underlying the role of ECRG4 in cancer remain elusive. An association between ECRG4 and proliferation, migration, cell cycle, apoptosis, methylation, and ubiquitination in cancer has been found. Additionally, some studies have investigated the regulatory mechanism of the relationship between ECRG4 and long non-coding RNAs, co-factors, and resistance to chemotherapy. Drugs that demethylate ECRG4 are in clinical use. Thus, further investigation of the mechanisms by which ECRG4 influences tumorigenesis, and its clinical significance, are needed. The present study outlines the current understanding of the functions of ECRG4 in cancer and discusses its potential value in cancer therapy.

[Immediate rehabilitation of edentulous mandibles with implant-supported full-arch prostheses by intra-oral welding technique: a two-year follow-up]

Objective: To evaluate the 2-year clinical outcome of immediate loading implant-supported fixed full-arch prostheses in mandibles using intra-oral welding technique and to discuss the characteristics of the technique. Methods: Totally 15 patients (4 males and 11 females) who treated with immediate rehabilitation of edentulous mandibles with implant-supported full-arch prostheses from July 2015 to February 2019 in Department of Implantology, Peking University School and Hospital of Stomatology were included in the present study. The patients' average age was 64.2±9.3 years. In each case, 4 implants were placed in the mandible area, a titanium bar was connected with each of the implants by using intra-oral welding technique as the Ti-metal framework of the prostheses. Pre-fabricated abutment-level fixed prostheses were delivered immediately after the surgery. A total of 60 implants, 15 mandibles were treated. Biological and mechanical complications, hygiene of the tissue-contacted surface of the restoration and patients' satisfactory grade were recorded. The radiological fitness of welded frameworks to abutments, survival rate of implants and marginal bone loss were calculated and analyzed. The observation period of the study was 24-55 months, with an average of 34.9 months. Results: All of the 15 cases of welded bar-abutment frameworks were fixed on implants with well passive fitness in clinical and radiological level. However, 2 of the 60 implants were failed by loss of osseointegration, and the result of implant survival rate of 96.7% in 2 years. The average marginal bone loss was (0.7±0.2) mm. The average bleeding index of the 58 implants remained was under 3 without clinical signs of gingival swelling, tenderness or fistula. No mechanical complications, such as break or distortion of the implants, occurred. Fracture of artificial teeth and complex resin area happened in 6 of the 15 prostheses. The average debris index was 3.4±0.4 and the hygiene of the tissue-contact areas was under satisfactory condition. Conclusions: Using the intra-oral welding technique to achieve a rigid splint of implants, the clinical outcome of the newly performed technique was predictable in early stage. The frame structure remained stable to avoiding the occurrence of mechanical complications. The provisional restoration could be expected to provide long functional period. Long term result of the treatment were needed for further observation.

The analysis of osteosarcopenia as a risk factor for fractures, mortality, and falls

Osteosarcopenia is defined as the concomitant occurrence of sarcopenia and osteoporosis/osteopenia. This study aimed to clarify whether osteosarcopenia implies a greater risk of fractures, mortality, and falls and to draw attention to osteosarcopenia.

INTRODUCTION

Osteosarcopenia, which is characterized by the co-existence of osteoporosis/osteopenia and sarcopenia, is one of the most challenging geriatric syndromes. However, the association between osteosarcopenia and the risk of falls, fractures, disability, and mortality is controversial.

METHODS

We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials, from their inception to March 18, 2021, for cohort studies on the relationship between osteosarcopenia and fractures, falls, and mortality. Two reviewers independently extracted data and assessed study quality. A pooled analysis was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) using fixed or random-effects models.

RESULTS

Eight cohort studies including 19,836 participants showed that osteosarcopenia significantly increased the risk of fracture (OR 2.46, 95% CI 1.83-3.30, P_{heterogeneity} = 0.006, I² = 63.0%), three cohort studies involving 2601 participants indicated that osteosarcopenia significantly increased the risk of mortality (OR 1.66, 95% CI 1.23-2.26, P_{heterogeneity} = 0.214, I² = 35.2%), and three cohort studies involving 3144 participants indicated that osteosarcopenia significantly increased the risk of falls (OR 1.62, 95% CI 1.28-2.04, P_{heterogeneity} = 0.219, I² = 34.1%). No publication bias existed among the studies regarding the association between osteosarcopenia and fractures. The findings were robust according to the subgroup and sensitivity analyses.

CONCLUSIONS

This pooled analysis demonstrated that osteosarcopenia significantly increased the risk of fractures, falls, and mortality, thus highlighting its relevance in daily life. Therefore, we suggest that elderly persons should be aware of the risks associated with osteosarcopenia.

Down-regulation of betatrophin enhances insulin sensitivity in type 2 diabetes mellitus through activation of the GSK-3β/PGC-1α signaling pathway

OBJECTIVE

The incidence of type 2 diabetes mellitus (T2DM) among children and adolescents has been rising. Accumulating evidences have noted the significant role of betatrophin in the regulation of lipid metabolism and glucose homeostasis. In our study, we tried to figure out the underlying mechanism of betatrophin in insulin resistance (IR) in type 2 diabetes mellitus (T2DM).

METHODS

First, fasting serum betatrophin, fasting blood glucose (FBG), insulin, total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) were detected in T2DM children. The homeostasis model assessment of insulin resistance (HOMA-IR), Gutt insulin sensitivity index (ISI_G) and Matsuda insulin sensitivity index (ISI_M) were calculated. A T2DM-IR mouse model was induced by high-fat diet, with the expression of GSK-3β and PGC-1α detected. Besides, HepG2 cells were induced by a high concentration of insulin to establish an IR cell model (HepG2-IR). The cell viability, glucose consumption, liver glycogen content, inflammation, and fluorescence level of GSK-3β and PGC-1α were analyzed.

RESULTS

Betatrophin was highly expressed in serum of T2DM children and was positively correlated with FBG, insulin, TC, TG, LDL-C and HOMA-IR, while negatively correlated with ISI_G and ISI_M. Betatrophin and GSK-3β in the liver tissues of T2DM-IR mice were increased, while the PGC-1α expression was decreased. Betatrophin expression was negatively correlated with PGC-1α and positively correlated with GSK-3β. Silencing of betatrophin enhanced insulin sensitivity through the activation of GSK-3β/PGC-1α signaling pathway. In vitro experiments also found that silencing of betatrophin promoted glucose consumption and glycogen synthesis while inhibited inflammation.

CONCLUSION

Our findings concluded that silencing of betatrophin could enhance insulin sensitivity and improve histopathological morphology through the activation of GSK-3β/PGC-1α signaling pathway.

Discovery of a Novel Specific Inhibitor Targeting Influenza A Virus Nucleoprotein with Pleiotropic Inhibitory Effects on Various Steps of the Viral Life Cycle

Influenza A viruses (IAVs) continue to pose an imminent threat to humans due to annual influenza epidemic outbreaks and episodic pandemics with high mortality rates. In this context, the suboptimal vaccine coverage and efficacy, coupled with recurrent events of viral resistance against a very limited antiviral portfolio, emphasize an urgent need for new additional prophylactic and therapeutic options, including new antiviral targets and drugs with new mechanisms of action to prevent and treat influenza virus infection. Here, we characterized a novel influenza A virus nucleoprotein (NP) inhibitor, FA-6005, that inhibited a broad spectrum of human pandemic and seasonal influenza A and B viruses in vitro and protects mice against lethal influenza A virus challenge. The small molecule FA-6005 targeted a conserved NP I41 domain and acted as a potentially broad, multimechanistic anti-influenza virus therapeutic since FA-6005 suppressed influenza virus replication and perturbed intracellular trafficking of viral ribonucleoproteins (vRNPs) from early to late stages. Cocrystal structures of the NP/FA-6005 complex reconciled well with concurrent mutational studies. This study provides the first line of direct evidence suggesting that the newly identified NP I41 pocket is an attractive target for drug development that inhibits multiple functions of NP. Our results also highlight FA-6005 as a promising candidate for further development as an antiviral drug for the treatment of IAV infection and provide chemical-level details for inhibitor optimization.IMPORTANCE Current influenza antivirals have limitations with regard to their effectiveness and the potential emergence of resistance. Therefore, there is an urgent need for broad-spectrum inhibitors to address the considerable challenges posed by the rapid evolution of influenza viruses that limit the effectiveness of vaccines and lead to the emergence of antiviral drug resistance. Here, we identified a novel influenza A virus NP antagonist, FA-6005, with broad-spectrum efficacy against influenza viruses, and our study presents a comprehensive study of the mode of action of FA-6005 with the crystal structure of the compound in complex with NP. The influenza virus inhibitor holds promise as an urgently sought-after therapeutic option offering a mechanism of action complementary to existing antiviral drugs for the treatment of influenza virus infection and should further aid in the development of universal therapeutics.

Overexpression and Inhibition of 3-Hydroxy-3-Methylglutaryl-CoA Synthase Affect Central Metabolic Pathways in Tobacco

Little has been established on the relationship between the mevalonate (MVA) pathway and other metabolic pathways except for the sterol and glucosinolate biosynthesis pathways. In the MVA pathway, 3-hydroxy-3-methylglutaryl-CoA synthase (HMGS) catalyzes the condensation of acetoacetyl-CoA and acetyl-CoA to form 3-hydroxy-3-methylglutaryl-coenzyme A. Our previous studies had shown that, while the recombinant Brassica juncea HMGS1 (BjHMGS1) mutant S359A displayed 10-fold higher enzyme activity than wild-type (wt) BjHMGS1, transgenic tobacco overexpressing S359A (OE-S359A) exhibited higher sterol content, growth rate and seed yield than OE-wtBjHMGS1. Herein, untargeted proteomics and targeted metabolomics were employed to understand the phenotypic effects of HMGS overexpression in tobacco by examining which other metabolic pathways were affected. Sequential window acquisition of all theoretical mass spectra quantitative proteomics analysis on OE-wtBjHMGS1 and OE-S359A identified the misregulation of proteins in primary metabolism and cell wall modification, while some proteins related to photosynthesis and the tricarboxylic acid cycle were upregulated in OE-S359A. Metabolomic analysis indicated corresponding changes in carbohydrate, amino acid and fatty acid contents in HMGS-OEs, and F-244, a specific inhibitor of HMGS, was applied successfully on tobacco to confirm these observations. Finally, the crystal structure of acetyl-CoA-liganded S359A revealed that improved activity of S359A likely resulted from a loss in hydrogen bonding between Ser359 and acyl-CoA, which is evident in wtBjHMGS1. This work suggests that regulation of plant growth by HMGS can influence the central metabolic pathways. Furthermore, this study demonstrates that the application of the HMGS-specific inhibitor (F-244) in tobacco represents an effective approach for studying the HMGS/MVA pathway.

[Serological study of Lyme disease antibody in 2 311 patients with arthritis symptoms in Hainan Province]

Objective: To understand the infectious status of Lyme disease among patients with arthritis symptoms in Hainan Province, and to provide a theoretical basis for prevention and control of Lyme disease. Methods: From 2013 to 2018, sampling surveys had been conducted in medical institutions in 8 cities in Hainan Province(Haikou, Sanya, Danzhou, Dongfang, Wenchang, Qionghai, Qiongzhong, Wuzhishan), 2 311 patients serum samples were collected with arthritis symptoms, and descriptive research were conducted base on the collected clinical data. The Indirect Fluorescent-Antibody Test (IFA) method was used for preliminary screening of Lyme disease antibody, the Western Blot (WB) method was used for IFA positive samples confirmation. Statistical analysis using χ² test. Results: 2 311 serum samples were tested by IFA, and 166 were positive with the positive rate of 7.18%. Further confirmed by WB method, 62 samples were positive, the positive rate of Lyme disease antibody was 2.68%(62/2 311). The positive rate of Lyme disease antibody among patients with arthritis in different regions of Hainan was statistically significant (χ²=40.636,P<0.001), and the positive rate in Qiongzhong city was the highest (8.81%, 14/159). Danzhou's positive rate was the second highest, 5.62%(5/89). Dongfang city had the lowest positive rate (0.51%, 2/394). The positive rates of Lyme disease serum antibody in men and women were 2.79% (33/1 182) and 2.57% (29/1 129), respectively; the positive rates of antibodies between each age groups were in the range of 1.74% to 3.64%. The antibody positive rate of Lyme disease showed no significant difference between gender and age (χ²=0.110,P=0.740 ;χ²=1.938,P=0.747). Conclusion: Patients with arthritis symptoms caused by Borrelia burgdorferi infection were found in 8 cities in Hainan province, but the Lyme disease antibody positive rate was different among cities, with Qiongzhong County being the highest.

The Role of Baseline Sarcopenia Index in Predicting Chemotherapy-Induced Undesirable Effects and Mortality in Older People with Stage III or IV Non-Small Cell Lung Cancer

OBJECTIVES

To assess the predictability value of Sarcopenia index( (SI, serum creatinine value/cystatin C value×100) in determining potential chemotherapy-induced undesirable reactions and eventual death of older patients diagnosed with stage III or IV of non-small cell lung cancer (NSCLC).

METHODS

General information was retrieved from health records and mortality data was obtained by phone interview. Serum Cr and CysC levels were measured before chemotherapy. The endpoints recorded were chemotherapy-induced undesirable reactions and mortality from any causes. Logit regression analysis was employed for the analysis of correlation between the SI and short-term adverse reactions to chemotherapy. Cox regression analysis was employed to analyze correlation between the SI and mortality.

RESULTS

In this study, 664 NSCLC patients were enrolled. Among them, 83.13% were diagnosed with adenocarcinoma lung cancer and 16.87% with squamous cell carcinoma lung cancer. As of March 1, 2019, 486 patients died, including 361(74.28%) males and 125 (25.72%) females. After the first course of chemotherapy, the proportion of short-term adverse reactions, including bone marrow suppression, digestive reactions, all infection, liver function impairment, and other adverse reactions (non-infectious fever or rashes) was 16%, 4.7%, 7.4, %, 6.6%, and 2.11%, respectively. After adjusting for confounding factors, there was no association between the SI and adverse reactions. We found that high SI was independently associated with a lower risk of mortality after adjusting for confounding factors in females (HR=0.593,95% CI: 0.382-0.92; p=0.02). There was no marked association existed between the SI and mortality in males.

CONCLUSION

Among patients with stage III or IV non-small cell lung cancer, the SI is associated with mortality in females, but not in males.

The Relationship between Pre-Admission Waiting Time and the Surgical Outcomes after Hip Fracture Operation in the Elderly

OBJECTIVES

To investigate the association between pre-admission waiting time and postoperative complications, length of stay (LOS), and costs during hospitalization.

METHOD

This was a single-center, observational study. The subjects of this study were elderly hip fracture patients who were admitted to the Department of Orthopedics, West China Hospital, Sichuan University, from December 2010 to June 14, 2017, and that underwent internal fixation or joint replacement surgery. The pre-admission waiting time was treated as a categorical variable according to median and first quartile values. Outcomes included postoperative complications (pneumonia and other complications [urinary tract infection, heart failure, non-A-grade healing]), LOS, and costs during hospitalization. LOS and costs during hospitalization were converted into binary outcomes based upon median values. Binary logistic regression analyses were used to analyze correlations between pre-admission waiting time and patient outcomes.

RESULTS

A total of 889 patients 60 years of age and older were enrolled in this study, of whom 65.47% were females and 34.53% were males. The proportion of patients with pre-admission waiting times less than 8 h, 8 - 24 h, and ≥ 24 h were 24.3%, 17.32%, and 58.38%, respectively. Postoperative pneumonia and other complications affected 12.04% and 6.30% of patients, respectively. Relative to patients with the pre-admission waiting times of less than 8 h, those with longer pre-admission waiting times exhibited a higher risk of postoperative pneumonia (8 - 24 h: OR = 2.72,95% CI: 1.29-5.74, p = 0.009; ≥ 24 h: OR = 2.76,95% CI: 1.48-5.14, p = 0.001). Patients with the pre-admission waiting time ≥ 24 h also exhibited a higher risk of the other complications (OR = 2.55, 95% CI: 1.53-4.26, p <0.001), a longer LOS (OR = 1.43, 95% CI:1.02-2.01, p = 0.036), and higher costs during hospitalization (OR = 1.51, 95% CI:1.05 - 2.17, p = 0.026) relative to patients with a waiting time less than 8 hours.

CONCLUSION

Pre-admission waiting time was associated with postoperative complications, LOS, and hospitalization costs among older Chinese patients undergoing surgery to treat hip fractures.

Single-step fluorescent probes to detect decrotonylation activity of HDACs through intramolecular reactions

Lysine crotonylation plays vital roles in gene transcription and cellular metabolism. Nevertheless, methods for dissecting the molecular mechanisms of decrotonyaltion remains limited. So far, there is no single-step fluorescent method developed for enzymatic decrotonylation activity detection. The major difficulty is that the aliphatic crotonylated lysine doesn't allow π-conjugation to a fluorophore and decrotonylation can not modulate the electronic state directly. Herein, we have designed and synthesized two activity-based single-step fluorogenic probes KTcr-I and KTcr-II for detecting enzymatic decrotonylation activity. These two probes can be recognized by histone deacetylases and undergo intramolecular nucleophilic exchange reaction to generate fluorescence signal. Notably, peptide sequence-dependent effect was observed. KTcr-I can be recognized by Sirt2 more effectively, while KTcr-II with LGKcr peptide sequence preferentially reacted with HDAC3. Compared to other methods of studying enzymatic decrotonylation activity, our single-step fluorescent method has a number of advantages, such as facileness, high sensitivity, cheap facility and little material consumed. We envision that the probes developed in this study will provide useful tools to screen inhibitors which suppress the decrotonylation activity of HDACs. Such probes will be useful for further delineating the roles of decrotonylation enzyme and aid in biomarker identification and drug discovery.

Crystal Structure of Human APPL BAR-PH Heterodimer Reveals a Flexible Dimeric BAR curve: Implication in Mutual Regulation of Endosomal Targeting

The APPL (adaptor proteins containing pleckstrin homology domain, phosphotyrosine binding domain and a leucine zipper motif) family consists of two isoforms, APPL1 and APPL2. By binding to curved plasma membrane, these adaptor proteins associate with multiple transmembrane receptors and recruit various downstream signaling components. They are involved in the regulation of signaling pathways evoked by a variety of extracellular stimuli, such as adiponectin, insulin, FSH (follicle stimulating hormone), EGF (epidermal growth factor). And they play important roles in cell proliferation, apoptosis, glucose uptake, insulin secretion and sensitivity. However, emerging evidence suggests that APPL1 and APPL2 perform different or even opposite functions and the underlying mechanism remains unclear. As APPL proteins can either homodimerize or heterodimerize in vivo, we hypothesized that heterodimerization of APPL proteins might account for the mechanism. By solving the crystal structure of APPL1-APPL2 BAR-PH heterodimer, we find that the overall structure is crescent-shaped with a longer curvature radius of 76 Å, compared to 55 Å of the APPL1 BAR-PH homodimer. However, there is no significant difference of the curvature between APPL BAR-PH heterodimer and APPL2 homodimer. The data suggest that the APPL1 BAR-PH homodimer, APPL2 BAR-PH homodimer and APPL1/APPL2 BAR-PH heterodimer may bind to endosomes of different sizes.   Different positive charge distribution is observed on the concave surface of APPL BAR-PH heterodimer than the homodimers, which may change the affinity of membrane association and subcellular localization. Collectively, APPL2 may regulate APPL1 function through altering the preference of endosome binding by heterodimerization.

Structural basis of DNA replication origin recognition by human Orc6 protein binding with DNA

The six-subunit origin recognition complex (ORC), a DNA replication initiator, defines the localization of the origins of replication in eukaryotes. The Orc6 subunit is the smallest and the least conserved among ORC subunits. It is required for DNA replication and essential for viability in all species. Orc6 in metazoans carries a structural homology with transcription factor TFIIB and can bind DNA on its own. Here, we report a solution structure of the full-length human Orc6 (HsOrc6) alone and in a complex with DNA. We further showed that human Orc6 is composed of three independent domains: N-terminal, middle and C-terminal (HsOrc6-N, HsOrc6-M and HsOrc6-C). We also identified a distinct DNA-binding domain of human Orc6, named as HsOrc6-DBD. The detailed analysis of the structure revealed novel amino acid clusters important for the interaction with DNA. Alterations of these amino acids abolish DNA-binding ability of Orc6 and result in reduced levels of DNA replication. We propose that Orc6 is a DNA-binding subunit of human/metazoan ORC and may play roles in targeting, positioning and assembling the functional ORC at the origins.

Crystal structure of the rice acyl-CoA-binding protein OsACBP2 in complex with C18:3-CoA reveals a novel pattern of binding to acyl-CoA esters

Acyl-CoA-binding proteins (ACBPs) are a family of proteins that bind acyl-CoA esters at a conserved acyl-CoA-binding domain. ACBPs maintain intracellular acyl-CoA pools to regulate lipid metabolism. Here, we report on the structure of rice OsACBP2 in complex with C18:3-CoA ester. The residues Y33, K34 and K56 of OsACBP2 play a crucial role in binding the CoA group, while residues N23, L27, K52 and Y55 in one molecule of OsACBP2 cooperate with L27, L28, A59 and A62 from another anchoring the fatty acyl group. Multiangle light scattering assays indicate that OsACBP2 binds C18:3-CoA as a monomer. The first complex structure of a plant ACBP binding with C18:3-CoA is therefore presented, providing a novel model for the interaction between an acyl-CoA ester and the acyl-CoA-binding domain(s).

Atomic differentiation of silver binding preference in protein targets: Escherichia coli malate dehydrogenase as a paradigm

Understanding how metallodrugs interact with their protein targets is of vital importance for uncovering their molecular mode of actions as well as overall pharmacological/toxicological profiles, which in turn facilitates the development of novel metallodrugs. Silver has been used as an antimicrobial agent since antiquity, yet there is limited knowledge about silver-binding proteins. Given the multiple dispersed cysteine residues and histidine-methionine pairs, Escherichia coli malate dehydrogenase (EcMDH) represents an excellent model to investigate silver coordination chemistry as well as its targeting sites in enzymes. We show by systematic biochemical characterizations that silver ions (Ag+) bind EcMDH at multiple sites including three cysteine-containing sites. By X-ray crystallography, we unravel the binding preference of Ag+ to multiple binding sites in EcMDH, i.e., Cys113 > Cys251 > Cys109 > Met227. Silver exhibits preferences to the donor atoms and residues in the order of S > N > O and Cys > Met > His > Lys > Val, respectively, in EcMDH. For the first time, we report the coordination of silver to a lysine in proteins. Besides, we also observed argentophilic interactions (Ag⋯Ag, 2.7 to 3.3 Å) between two silver ions coordinating to one thiolate. Combined with site-directed mutagenesis and an enzymatic activity test, we unveil that the binding of Ag+ to the site IV (His177-Ag-Met227 site) plays a vital role in Ag+-mediated MDH inactivation. This work stands as the first unusual and explicit study of silver binding preference to multiple binding sites in its authentic protein target at the atomic resolution. These findings enrich our knowledge on the biocoordination chemistry of silver(i), which in turn facilitates the prediction of the unknown silver-binding proteins and extends the pharmaceutical potentials of metal-based drugs.

RSF-1 siRNA Enhances Tumor Radiosensitivity in Cervical Cancer via Enhanced DNA Damage, Cell Cycle Redistribution, and Promotion of Apoptosis

Background

Remodeling and spacing factor-1 (RSF-1) is an identified tumor biomarker that is overexpressed in a variety of human cancers, but its effect on radiotherapy remains unclear. In this study, we aimed to explore the effect of RSF-1 siRNA on sensitizing cervical cancer cells to radiation and its underlying mechanism.

Methods

The mRNA and protein expression of RSF-1 in tissue and cells were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. Cell counting kit-8 (CCK-8) and colony formation assay were used to examine cell proliferation. Flow cytometry was used to analyzed the cell cycle and cell apoptosis. DNA damage was examined by the comet assay. ATM, ATR, CHK1, CHK2, H2AX, γH2AX and phosphorylated ATM, ATR, CHK1 and CHK2 were detected by Western blotting. γH2AX foci were demonstrated by immunofluorescence staining.

Results

RSF-1 was upregulated in cervical cancer tissue and decreased after effective treatment. RSF-1 siRNA in combination with radiation suppressed cell viability, redistributed cell cycles and also induced cell apoptosis in HeLa and SiHa cell lines. Further, knockdown of RSF-1 induced DNA damage by attenuating DNA repair capability, thereby sensitizing cervical cancer cells to radiation.

Conclusions

These data demonstrate that RSF-1 siRNA enhanced the sensitivity of radiotherapy, and targeting RSF-1 may be a promising approach for the development of novel radiosensitizing agents for the treatment of cervical cancer.

Vessel Wall MRI Enhancement in Noninflammatory Cerebral Amyloid Angiopathy

Cerebral amyloid angiopathy is characterized by deposition of amyloid-β fibrils in the walls of small-to-medium-sized blood vessels. In this retrospective review of 5 patients with histologically confirmed noninflammatory cerebral amyloid angiopathy, high-resolution vessel wall MRI showed arterial wall enhancement in 2 patients (40%). Despite common consensus of equating vessel wall enhancement with inflammation, this report demonstrates that β-amyloid accumulation alone without inflammation can be associated with arterial wall enhancement in a subset of patients.

IPCAS: a direct-method-based pipeline from phasing to model building and refinement for macromolecular structure determination

A new version (2.0) of the pipeline IPCAS (Iterative Protein Crystal structure Automatic Solution) has been released, in which the program OASIS performs direct-method single-wavelength anomalous diffraction/single isomorphous replacement phasing and direct-method-aided partial-structure extension. IPCAS incorporates the widely used packages CCP4 and PHENIX for locating heavy atoms, density modification, molecular replacement, model building and refinement. Important extensions to the previous version of IPCAS include a resolution screening method for non-crystallographic symmetry searching, an alternate model-building protocol for avoiding premature convergence and direct-method image processing for electron microscopy maps, including single-particle cryo-EM maps. Moreover, a new graphical user interface is provided for controlling and real-time monitoring of the whole dual-space iterative process, which works as a plugin to CCP4i. Applications of the new IPCAS to difficult cases have yielded promising results, including `direct-method phasing and fragment extension' from weak anomalous diffraction signal data and `direct-method-aided partial-structure extension' from low-homology models.

Ethnic Groups Differences in the Prevalence of Sarcopenia Using the AWGS Criteria

OBJECTIVES

To estimate the prevalence of sarcopenia in different ethnic groups and the association with cultural life styles in west China.

DESIGN

A cross-sectional study.

SETTINGS

The communities in Yunnan, Guizhou, Sichuan, and Xinjiang provinces.

PARTICIPANTS

4500 participants aged 50 years or older in west China were enrolled in this study. Sarcopenia was defined according to the diagnostic algorithm of the Asia Working Group for Sarcopenia (AWGS).

MEASUREMENTS

We measured gait speed, handgrip strength and muscle mass by using bioelectrical impedance analysis (BIA) for all eligible participants. Life-style information were collected by reviewers. Relationships between sarcopenia and ethnic groups were analyzed using univariate and multivariate analyses.

RESULTS

We found 869 (19.31%) adults aged 50 years old or older were sarcopenia. The mean age is 62.4±8.3 years. The main ethnic groups enrolled in this study is Han, Tibetan, Qiang, Yi and Hui. The crude prevalence of sarcopenia is 22.3% in Han, 18.2% in Tibetan, 11.8% in Qiang, 34.7% in Yi and 26.7% in Hui. Compared to Han, after adjusting sex and age, Qiang has a lower prevalence of sarcopenia (odds ratio [OR]: 0.44, 95% CI 0.35-0.55), Yi has a higher prevalence of sarcopenia (OR: 1.78, 95% CI 1.29-2.43). While adding adjusting other potential cofounders, sarcopenia is still less prevalent in Qiang (OR: 0.44, 95% CI 0.34-0.57).

CONCLUSIONS

The crude prevalence of sarcopenia is 22.3% in Han, 18.2% in Tibetan, 11.8% in Qiang, 34.7% in Yi and 26.7% in Hui. Sarcopenia was less prevalent in Qiang compared with Han. Further studies to determine related factors of sarcopenia among different ethnic groups are recommended.

Using cryo-electron microscopy maps for X-ray structure determination of homologues

The combination of cryo-electron microscopy (cryo-EM) and X-ray crystallography reflects an important trend in structural biology. In a previously published study, a hybrid method for the determination of X-ray structures using initial phases provided by the corresponding parts of cryo-EM maps was presented. However, if the target structure of X-ray crystallography is not identical but homologous to the corresponding molecular model of the cryo-EM map, then the decrease in the accuracy of the starting phases makes the whole process more difficult. Here, a modified hybrid method is presented to handle such cases. The whole process includes three steps: cryo-EM map replacement, phase extension by NCS averaging and dual-space iterative model building. When the resolution gap between the cryo-EM and X-ray crystallographic data is large and the sequence identity is low, an intermediate stage of model building is necessary. Six test cases have been studied with sequence identity between the corresponding molecules in the cryo-EM and X-ray structures ranging from 34 to 52% and with sequence similarity ranging from 86 to 91%. This hybrid method consistently produced models with reasonable R_work and R_free values which agree well with the previously determined X-ray structures for all test cases, thus indicating the general applicability of the method for X-ray structure determination of homologues using cryo-EM maps as a starting point.

Sarcopenia, Obesity and Sarcopenia Obesity in Comparison: Prevalence, Metabolic Profile, and Key Differences: Results from WCHAT Study

OBJECTIVE

To identify the prevalence, lifestyle factors, chronic disease status, and assessing the metabolic profile, comparing key differences in a cohort of subjects with non-sarcopenia/non-obesity (H), sarcopenia/non-obesity (S), non-sarcopenia/obesity (O) and sarcopenia obesity (SO) in a multi-ethnic population in west China.

DESIGN

A cross-sectional study.

SETTING

The communities in Yunnan, Guizhou, Sichuan, and Xinjiang provinces.

PARTICIPANTS

We included 4,500 participants aged 50 years or older who did bioelectrical impedance in our analysis from West China Health and Aging Trend (WCHAT) study.

MEASUREMENTS

We measured gait speed, handgrip strength and muscle mass by using bioelectrical impedance analysis (BIA) for all participants. We defined sarcopenia using the diagnostic algorithm recommended by the Asian Working Group for Sarcopenia (AWGS). Obesity was defined as the highest sex-specific quintile of the percentage body fat. Different variables like anthropometry measures, life styles, chronic disease and blood test were collected. Analysis of variance and a multinomial logistic regression analysis adjusting for covariates were used to assess the differences of metabolic profiles among different groups.

RESULTS

Of 4500 participants aged 50 years old or older, the proportions of H, O, S, SO were 63.0%, 17.7%, 16.7% and 2.6%, respectively. And the prevalence of S subjects in men was 18.3% and 15.7% in women, while the prevalence of SO was 3.7% in men and 2.0% in women. Data showed that the prevalence of S and SO has an aging increase pattern which was opposite with O. Both S and SO tends to be older, lower educational level, without spouse, smoking, comorbidity of chronic disease, poor nutrition status, depression and cognitive decline compared to H and S seems to be worse than SO. Compared to H, S cohort showed a decrease in Vitamin D, triglyceride, albumin, fasting glucose, insulin, creatinine, ALT, nutrition scores and increase in HDL. SO cohort were observed for an increase in cholesterol, LDL, total protein and decrease in vitamin D. While O cohort showed an increase in triglyceride, cholesterol, LDL, total protein, glucose, insulin, WBC, uric acid, ALT and nutrition scores, but a decrease in HDL and vitamin D level.

CONCLUSIONS

Among individuals aged 50 years old or older in West China. S, O and SO participants demonstrate distinct differences in the life-styles, chronic disease profile, and metabolic profiles. The prevalence of S and SO has an aging increase pattern contrary to O. Both S and SO tend to be older, lower educational level, without spouse, smoking, comorbidity of chronic disease, poor nutrition status, depression and cognitive decline compared to H and S looks like to be worse than SO. Besides, the S subjects seem to have more metabolic index changes than SO compared to H. While O subjects have some contrary metabolic index to S subjects.

Chemical Probes Reveal Sirt2's New Function as a Robust "Eraser" of Lysine Lipoylation

Lysine lipoylation, a highly conserved lysine post-translational modification, plays a critical role in regulating cell metabolism. The catalytic activity of a number of vital metabolic proteins, such as pyruvate dehydrogenase (PDH), depends on lysine lipoylation. Despite its important roles, the detailed biological regulatory mechanism of lysine lipoylation remains largely unexplored. Herein we designed a powerful affinity-based probe, KPlip, to interrogate the interactions of lipoylated peptide/proteins under native cellular environment. Large-scale chemical proteomics analysis revealed a number of binding proteins of KPlip, including sirtuin 2 (Sirt2), an NAD⁺-dependent protein deacylase. To explore the potential activity of Sirt2 toward lysine lipoylation, we designed a single-step fluorogenic probe, KTlip, which reports delipoylation activity in a continuous manner. The results showed that Sirt2 led to significant delipoylation of KTlip, displaying up to a 60-fold fluorescence increase in the assay. Further kinetic experiments with different peptide substrates revealed that Sirt2 can catalyze the delipoylation of peptide (DLAT-PDH, K259) with a remarkable catalytic efficiency (k_cat/K_m) of 3.26 × 10³ s^-1 M^-1. The activity is about 400-fold higher than that of Sirt4, the only mammalian enzyme with known delipoylation activity. Furthermore, overexpression and silencing experiments demonstrated that Sirt2 regulates the lipoylation level and the activity of endogenous PDH, thus unequivocally confirming that PDH is a genuine physiological substrate of Sirt2. Using our chemical probes, we have successfully established the relationship between Sirt2 and lysine lipoylation in living cells for the first time. We envision that such chemical probes will serve as useful tools for delineating the roles of lysine lipoylation in biology and diseases.

LOXL 2 Promotes The Epithelial-Mesenchymal Transition And Malignant Progression Of Cervical Cancer

Purpose

Increasing evidence suggests that lysyl oxidase-like 2 (LOXL2) contributes to tumor progression. However, the role of LOXL2 in cervical cancer still remains unclear.

Patients and methods

We used the TCGA database to analyze the expression of LOXL2 in cervical cancer and its role on survival. The effects of LOXL2 on cervical cancer metastasis and EMT were verified by transwell and wound healing assay. Western blot assay was used to detect the effect of LOXL2 on EMT-related gene expression. In addition, we used animal experiments to observe the role of LOXL2 on tumor genesis and metastasis in cervical cancer.

Results

Here we found that LOXL2 participates in epithelial–mesenchymal transition-related cervical cancer progression. LOXL2 ablation in cervical cancer cells inhibited cell metastatic ability, whereas LOXL2 overexpression promoted cell metastasis. In addition, more clinical data from TCGA revealed that LOXL2 is closely related to the prognosis and is highly expressed in highly malignant and metastatic cervical tumors.

Conclusion

Taken together, our findings established a pathophysiologic role and new function for LOXL2 in cervical cancer metastasis.

Antimicrobial silver targets glyceraldehyde-3-phosphate dehydrogenase in glycolysis of E. coli

Silver has long been used as an antibacterial agent, yet its molecular targets remain largely unknown. Using a custom-designed coupling of gel electrophoresis with inductively coupled plasma mass spectrometry (GE-ICP-MS), we identified six silver-binding proteins in E. coli. The majority of the identified proteins are associated with the central carbon metabolism of E. coli. Among them, we unveil that GAPDH, an essential enzyme in glycolysis, serves as a vital target of Ag+ in E. coli for the first time. We demonstrate that silver inhibits the enzymatic function of GAPDH through targeting Cys149 in its catalytic site. The X-ray structure reveals that Ag+ coordinates to Cys149 and His176 with a quasi-linear geometry (S-Ag-N angle of 157°). And unexpectedly, two Ag+ ions coordinate to Cys288 in the non-catalytic site with weak argentophilic interaction (Ag···Ag distance of 2.9 Å). This is the first report on antimicrobial Ag+ targeting a key enzyme in the glycolytic pathway of E. coli. The findings expand our knowledge on the mode of action and bio-coordination chemistry of silver, particularly silver-targeting residues in proteins at the atomic level.

Mp1p homologues as virulence factors in Aspergillus fumigatus

Recently, we showed that Mp1p is an important virulence factor of Talaromyces marneffei, a dimorphic fungus phylogenetically closely related to Aspergillus fumigatus. In this study, we investigated the virulence properties of the four Mp1p homologues (Afmp1p, Afmp2p, Afmp3p, and Afmp4p) in A. fumigatus using a mouse model. All mice died 7 days after challenge with wild-type A. fumigatus QC5096, AFMP1 knockdown mutant, AFMP2 knockdown mutant and AFMP3 knockdown mutant and 28 days after challenge with AFMP4 knockdown mutant (P<.0001). Only 11% of mice died 30 days after challenge with AFMP1-4 knockdown mutant (P<.0001). For mice challenge with AFMP1-4 knockdown mutant, lower abundance of fungal elements was observed in brains, kidneys, and spleens compared to mice challenge with QC5096 at day 4 post-infection. Fungal counts in brains of mice challenge with QC5096 or AFMP4 knockdown mutant were significantly higher than those challenge with AFMP1-4 knockdown mutant (P<.01 and P<.05). Fungal counts in kidneys of mice challenge with QC5096 or AFMP4 knockdown mutant were significantly higher than those challenge with AFMP1-4 knockdown mutant (P<.001 and P<.001) and those of mice challenge with QC5096 were significantly higher than those challenge with AFMP4 knockdown mutant (P<.05). There is no difference among the survival rates of wild-type A. fumigatus, AFMP4 knockdown mutant and AFMP1-4 knockdown mutant, suggesting that Mp1p homologues in A. fumigatus do not mediate its virulence via improving its survival in macrophage as in the case in T. marneffei. Afmp1p, Afmp2p, Afmp3p, and Afmp4p in combination are important virulence factors of A. fumigatus.

[Regulatory effect of exosomes secreted by vaginal wall fibroblasts on angiogenesis in patients with stress urinary incontinence]

Objective: Exosomes are considered to mediate intercellular communication by delivering biomolecules like mRNA, miRNA into recipient cells. The purpose of this study was to evaluate the effects of exosomes secreted by fibroblasts from women with stress urinary incontinence (SUI-EXO) on endothelial cells angiogenesis. Methods: Primary fibroblasts were acquired from periurethral vaginal wall tissues and exosomes were prepared by ultracentrifugation of fibroblasts cells conditioned medium. The expression levels of pro-angiogenic and anti-angiogenic genes were assessed using qRT-PCR analysis. Migration of endothelial cells was measured by transwell assay, and the effects of SUI-EXO on angiogenesis were evaluated by performing a tube formation assay in vitro. Results: SUI-EXO was successfully isolated from fibroblasts cells conditional medium and transferred to endothelial cells efficiently. When the endothelial cells were treated with SUI-EXO, the expression levels of pro-angiogenic genes in fibroblasts were downregulated, and the expression levels of anti-angiogenic genes were upregulated significantly (P<0.01). Endothelial cells exhibited a decreased migratory capacity after treatment with SUI-EXO compared to exosomes from health women (64.6±8.7 vs 114.5±14.2,P<0.01), and tube formation of endothelial cells was also significantly inhibited in the SUI-EXO treated group as determined by the increase of the tube length (87.6±13.3 vs 168.5±28.3,P<0.01). Conclusion: This study suggests that SUI-EXO plays related roles in regulating endothelial cells angiogenesis and SUI-EXO maybe involve in the pathogenesis of SUI.

The Association between Sarcopenia and Prealbumin Levels among Elderly Chinese Inpatients

OBJECTIVES

The goal of the present study was to assess the relationship between sarcopenia and prealbumin levels among hospitalized patients ages 60 and older.

DESIGN

Cross-sectional study.

SETTING

The geriatric wards in Guizhou Provincial People's Hospital, Guiyang. Guizhou, China.

MEASUREMENTS

Sarcopenia was defined according to the Asian Working Group for Sarcopenia (AWGS) criteria, which consist of three components: low muscle mass, assessed based on an index of appendicular skeletal mass/height2 <7.0kg/m2 for men and <5.4kg/m2 for women; low muscle strength, defined as handgrip strength <26kg for men and <18kg for women; and low physical performance, defined as gait speed <0.8m/s. Using these criteria, sarcopenia was defined as presence of low muscle mass in addition to low muscle strength and/or low physical performance. Prealbumin levels and other variables were considered as being independent variables in an effort to evaluate any potential associations between these factors and sarcopenia status using non-adjusted and multivariate-adjusted regression models.

RESULTS

The overall prevalence of sarcopenia was 60.17%, affecting 65 (70.65%) men and 6 (23.08%) women in the present study. Age, body mass index (BMI), and prealbumin levels were each independently associated with sarcopenia (p<0.05). In a multivariate model, after adjusting for all potential covariates, prealbumin levels remained significantly associated with sarcopenia incidence, with an inflection point of 265.9mg/L. The effect sizes and the confidence intervals on the left and right sides of this inflection point were 0.94 (0.90 to 0.99) and 1.07 (0.93 to 1.23), respectively.

CONCLUSION

Among older Chinese inpatients in the present study, prealbumin levels were negatively correlated with sarcopenia incidence, when prealbumin levels were below 265.9mg/L.

Lysine benzoylation is a histone mark regulated by SIRT2

Metabolic regulation of histone marks is associated with diverse biological processes through dynamically modulating chromatin structure and functions. Here we report the identification and characterization of a histone mark, lysine benzoylation (K_bz). Our study identifies 22 K_bz sites on histones from HepG2 and RAW cells. This type of histone mark can be stimulated by sodium benzoate (SB), an FDA-approved drug and a widely used chemical food preservative, via generation of benzoyl CoA. By ChIP-seq and RNA-seq analysis, we demonstrate that histone K_bz marks are associated with gene expression and have physiological relevance distinct from histone acetylation. In addition, we demonstrate that SIRT2, a NAD⁺-dependent protein deacetylase, removes histone K_bz both in vitro and in vivo. This study therefore reveals a new type of histone marks with potential physiological relevance and identifies possible non-canonical functions of a widely used chemical food preservative.

Histone marks regulate chromatin structure and function. Here the authors identify and characterize lysine benzoylation, a histone mark that can be modulated by sodium benzoate, a widely used chemical food preservative, associated with specific regulation of gene expression.

IL-27 regulates HIF-1α-mediated VEGFA response in macrophages of diabetic retinopathy patients and healthy individuals

Human macrophages produce vascular endothelial growth factor A (VEGFA) for angiogenesis in diabetic retinopathy (DR). The regulatory function of IL-27 on human macrophages is not well understood. In particular, the effect of IL-27 on VEGFA response in human macrophages has not been investigated. We find that IL-27 suppresses VEGFA mRNA expression as well as protein secretion by human macrophages. The synergistic action of purinergic signaling and activation of hypoxia-inducible factor 1 alpha (HIF-1α) induces VEGFA production in a positive feedback loop. IL-27 signaling in human macrophages disrupts this positive feedback loop thus suppresses VEGFA production. Blockade of IL-27 signaling with a JAK2 antagonist reverses this downregulatory effect on HIF-1α and partially blocks the inhibitory effect on VEGFA production. Lastly, DR patient macrophages have a higher propensity to produce VEGFA and this is amplified by an in vitro challenge with the pro-inflammatory cytokine IL-1β. IL-27 suppresses VEGFA production by DR patient macrophages even in the presence of IL-1β challenge indicating a potential therapeutic use of IL-27 in the clinic.

Using cryo-electron microscopy maps for X-ray structure determination

X-ray crystallography and cryo-electron microscopy (cryo-EM) are complementary techniques for structure determination. Crystallography usually reveals more detailed information, while cryo-EM is an extremely useful technique for studying large-sized macromolecules. As the gap between the resolution of crystallography and cryo-EM data narrows, the cryo-EM map of a macromolecule could serve as an initial model to solve the phase problem of crystal diffraction for high-resolution structure determination. FSEARCH is a procedure to utilize the low-resolution molecular shape for crystallographic phasing. The IPCAS (Iterative Protein Crystal structure Automatic Solution) pipeline is an automatic direct-methods-aided dual-space iterative phasing and model-building procedure. When only an electron-density map is available as the starting point, IPCAS is capable of generating a completed model from the phases of the input map automatically, without the requirement of an initial model. In this study, a hybrid method integrating X-ray crystallography with cryo-EM to help with structure determination is presented. With a cryo-EM map as the starting point, the workflow of the method involves three steps. (1) Cryo-EM map replacement: FSEARCH is utilized to find the correct translation and orientation of the cryo-EM map in the crystallographic unit cell and generates the initial low-resolution map. (2) Phase extension: the phases calculated from the correctly placed cryo-EM map are extended to high-resolution X-ray data by non-crystallographic symmetry averaging with phenix.resolve. (3) Model building: IPCAS is used to generate an initial model using the phase-extended map and perform model completion by iteration. Four cases (the lowest cryo-EM map resolution being 6.9 Å) have been tested for the general applicability of the hybrid method, and almost complete models have been generated for all test cases with reasonable Rwork/Rfree. The hybrid method therefore provides an automated tool for X-ray structure determination using a cryo-EM map as the starting point.

Association of sarcopenia and fractures in community-dwelling older adults: a systematic review and meta-analysis of cohort studies

To our knowledge, no comprehensive meta-analysis has examined the association between sarcopenia and the risk of fractures. This systematic review and meta-analysis of prospective cohort studies aims to summarize whether sarcopenia is a risk factor for fractures among community-dwelling older adults. We searched four electronic literature databases (Ovid MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, PubMed) for relevant publications from inception to December 2017, using relevant keywords. We conducted a pooled analysis of the association between sarcopenia and the risk of fractures by employing a random-effects model. Subgroup analyses were conducted based on definitions of sarcopenia and gender. In total, nine studies were included in our systematic review and meta-analysis. The prevalence of sarcopenia ranged from 4.3 to 33.1%. The pooled RR of fractures for the sarcopenic versus the nonsarcopenic was 1.34 (95% CI = 1.13-1.58, P = 0.001, I² = 5.5%, P-heterogeneity = 0.391). Subgroup analyses showed that associations between sarcopenia and fractures were significant when using the AWGS definition (combined effect size = 1.78, 95% CI = 1.25-2.54, P = 0.001), and studies in males (combined effect size = 1.39, 95% CI = 1.13-1.71, P = 0.002). In conclusion, we found that compared to nonsarcopenic, the association between sarcopenia and fractures among community-dwelling older people was significant when using the AWGS definition, and only for males. Future studies are needed to establish a possible association between sarcopenia definitions and risk of fractures of different sites.

[Antimicrobial susceptibility and drug-resistance genes of Yersinia spp. of retailed poultry in 4 provinces of China]

Objective: To monitor the antimicrobial resistance and drug-resistance genes of Yersinia enterocolitis, Y. intermedia and Y. frederiksenii recovered from retailed fresh poultry of 4 provinces of China. Methods: The susceptibility of 25 isolated Yersinia spp. to 14 classes and 25 kinds of antibiotics was determined by broth microdilution method according to CLSI (Clinical and Laboratory Standards Institute). The antibiotic resistance genes were predicted with antibiotic resistance genes database (ARDB) using whole genome sequences of Yersinia spp. Results: In all 22 Y. enterocolitis tested, 63.7% (14 isolates), 22.8% (5 isolates), 4.6% and 4.6% of 1 isolates exhibited the resistance to cefoxitin, ampicillin-sulbactam, nitrofurantoin and trimethoprim-sulfamethoxazole, respectively. All the 25 isolates were multi-drug resistant to more than 3 antibiotics, while 64.0% of isolates were resistant to more than 4 antibiotics. A few Y. enterocolitis isolates of this study were intermediate to ceftriaxone and ciprofloxacin. Most Yersinia spp. isolates contained antibiotic resistance genes mdtG, ksgA, bacA, blaA, rosAB and acrB, and 5 isolates recovered from fresh chicken also contained dfrA1, catB2 and ant3ia. Conclusion: The multi-drug resistant Yersinia spp. isolated from retailed fresh poultry is very serious in the 4 provinces of China, and their contained many kinds of drug-resistance genes.

Haploinsufficiency of Trp53 dramatically extends the lifespan of Sirt6-deficient mice

Mammalian sirtuin 6 (Sirt6) is a conserved NAD⁺-dependent deacylase and mono-ADP ribosylase that is known to be involved in DNA damage repair, metabolic homeostasis, inflammation, tumorigenesis, and aging. Loss of Sirt6 in mice results in accelerated aging and premature death within a month. Here, we show that haploinsufficiency (i.e., heterozygous deletion) of Trp53 dramatically extends the lifespan of both female and male Sirt6-deficient mice. Haploinsufficiency of Trp53 in Sirt6-deficient mice rescues several age-related phenotypes of Sirt6-deficient mice, including reduced body size and weight, lordokyphosis, colitis, premature senescence, apoptosis, and bone marrow stem cell decline. Mechanistically, SIRT6 deacetylates p53 at lysine 381 to negatively regulate the stability and activity of p53. These findings establish that elevated p53 activity contributes significantly to accelerated aging in Sirt6-deficient mice. Our study demonstrates that p53 is a substrate of SIRT6, and highlights the importance of SIRT6-p53 axis in the regulation of aging.

Almost without exception, mammals age as they grow older. Older mammals are at greater risk of diseases like cancer, and have fewer stem cells that would otherwise help to keep their organs healthy. Some of the proteins that regulate and impact upon aging have been identified. One of these is an enzyme called SIRT6, which is thought to promote longevity. Mice without any SIRT6 suffer from severe premature aging, and rather than living up to two years like normal mice, SIRT6-deficient mice die within one month of their birth. The mutant mice also lose stem cells and exhibit signs of organ degeneration and body wasting.

Another protein called p53 is well known for having the opposite effect to SIRT6: it accelerates aging and helps to prevent tumor growth. However, it was unclear if p53 is also involved in the processes that lead to the premature death of mice without SIRT6.

Now, Ghosh et al. report that mouse cells and tissues without SIRT6 have more p53 compared to control samples. Biochemical experiments showed that the SIRT6 and p53 proteins physically interact, and that SIRT6 could use its enzymatic activity to remove a chemical modification, called acetylation, from p53. Without this specific acetylation, p53 became less stable and its levels dropped. Consequently, p53 was stabilized in the SIRT6-deficient cells. When Ghosh et al. deleted one copy of the gene that codes for p53 in SIRT6-deficient mice, mutant mice that had before only lived for a month now lived for up to sixteen months. Additionally, the mice were healthier, showing fewer signs of aging: for example, they had more immune cells and stem cells, straighter spines, and showed less gut inflammation and less body wasting.

These findings suggest that SIRT6 does indeed inhibit p53 to counteract the normal aging process. Future experiments may explore if this regulation also holds true in human cells. Detailed knowledge of these molecular interactions could also open up more research into therapies against cancer and aging.

Adherence to the Mediterranean Diet and the Risk of Frailty in Old People: A Systematic Review and Meta-Analysis

BACKGROUND

Frailty is a common geriatric syndrome in old people. It remains controversial whether Mediterranean diet could prevent old people from developing into frailty. The aim of this study is to summarize the relevant studies and assess the effectiveness of adherence to Mediterranean diet on frailty in old people.

METHOD

A systematic search of MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials was conducted to identify all relevant studies up to Oct 2017. We included studies regarding the associations between adherence to Mediterranean diet and risk of frailty among elders. A meta-analysis was performed to explore the effects of Mediterranean diet on frailty.

RESULTS

Six studies matched the inclusion criteria, of which five were prospective and one was cross-sectional. A total of 10,210 participants from the five prospective cohort studies were included to perform the meta-analyses. In comparison with lowest adherence to Mediterranean diet, elders with highest adherence to Mediterranean diet were significantly associated with lower risk of frailty in the future (RR= 0.56, 95% CI=0.36-0.89, p=0.015). Furthermore, the pooled estimates from four studies performed among participants in western countries (European and North American) showed that higher adherence to Mediterranean diet was associated with a 52% reduced risk of frailty (RR= 0.48, 95% CI=0.32-0.72, p<0.001). However, one study showed no association between Mediterranean diet and frailty among Asian elders (RR=1.06, 95% CI=0.83-1.36, p=0.638).

CONCLUSION

A higher adherence to Mediterranean diet is associated with a lower risk of frailty in old people. Meanwhile, the benefits may be more obvious among elders from western countries.

A circular white-light flare with impulsive and gradual white-light kernels

White-light flares are the flares with emissions visible in the optical continuum. They are thought to be rare and pose the most stringent requirements in energy transport and heating in the lower atmosphere. Here we present a nearly circular white-light flare on 10 March 2015 that was well observed by the Optical and Near-infrared Solar Eruption Tracer and Solar Dynamics Observatory. In this flare, there appear simultaneously both impulsive and gradual white-light kernels. The generally accepted thick-target model would be responsible for the impulsive kernels but not sufficient to interpret the gradual kernels. Some other mechanisms including soft X-ray backwarming or downward-propagating Alfvén waves, acting jointly with electron beam bombardment, provide a possible interpretation. However, the origin of this kind of white-light kernel is still an open question that induces more observations and researches in the future to decipher it.