Interaction analysis of RNA G-quadruplex with ligands and in situ imaging application.

RNA G4, as an integral branch of G4 structure, possesses distinct interactions with ligands compared to the common DNA G4, thus the investigation of RNA G4/ligand interactions might be considered as a fresh breakthrough to improve the biosensing performance of G4/ligand system. In this study, we comparatively explored the structural and functional mechanisms of RNA G4 and DNA G4 in the interaction with ligands, hemin and thioflavin T (ThT), utilizing the classical PS2.M sequence as a model. We found that although the catalytic performance of RNA G4/hemin system was lower than DNA G4/hemin, RNA G4/ThT fluorescence system exhibited a significant improvement (2∼3-fold) compared to DNA G4/ThT, and adenine modification could further enhance the signaling. Further, by exploring the interaction between RNA G4 and ThT, we deemed that RNA G4 and ThT were stacked in a bimolecular mode compared to single-molecule binding of DNA G4/ThT, thus more strongly limiting the structural spin in ThT excited state. Further, RNA G4/ThT displayed higher environmental tolerance and lower ion dependence than DNA G4/ThT. Finally, we employed RNA G4/ThT as a highly sensitive label-free fluorescent signal output system for in situ imaging of isoforms BCR-ABL e13a2 and e14a2. Overall, this study successfully screened a high-performance RNA G4 biosensing system through systematic RNA G4/ligands interaction studies, which was expected to provide a promising reference for subsequent G4/ligand research.

Epidemiological characteristics and clinical antibiotic resistance analysis of Ureaplasma urealyticum infection among women and children in southwest China.

BACKGROUND: The aim of this study was to investigate the epidemiological characteristics and antibiotic resistance patterns of Ureaplasma urealyticum (UU) infection among women and children in southwest China. METHODS: A total of 8,934 specimens, including urogenital swabs and throat swabs were analyzed in this study. All samples were tested using RNA-based Simultaneous Amplification and Testing (SAT) methods. Culture and drug susceptibility tests were performed on UU positive patients. RESULTS: Among the 8,934 patients, the overall positive rate for UU was 47.92%, with a higher prevalence observed among women of reproductive age and neonates. The majority of UU positive outpatients were women of reproductive age (88.03%), while the majority of UU positive inpatients were neonates (93.99%). Overall, hospitalization rates due to UU infection were significantly higher in neonates than in women. Further analysis among neonatal inpatients revealed a higher incidence of preterm birth and low birth weight in UU positive inpatients (52.75% and 3.65%, respectively) than in UU negative inpatients (44.64% and 2.89%, respectively), especially in very preterm and extremely preterm neonates. Moreover, the incidence rate of bronchopulmonary dysplasia (BPD) among hospitalized neonatal patients was significantly higher in the UU positive group (6.89%) than in the UU negative group (4.18%). The drug susceptibility tests of UU in the neonatology, gynecology and obstetrics departments exhibited consistent sensitivity patterns to antibiotics, with high sensitivity to tetracyclines and macrolides, and low sensitivity to fluoroquinolones. Notably, UU samples collected from the neonatology department exhibited significantly higher sensitivity to azithromycin and erythromycin (93.8% and 92.9%, respectively) than those collected from the gynecology and obstetrics departments. CONCLUSIONS: This study enhances our understanding of the current epidemiological characteristics and antibiotic resistance patterns of UU infection among women and children in southwest China. These findings can aid in the development of more effective intervention, prevention and treatment strategies for UU infection.

Poor nutritional status is associated with the severity of omicron infection in the older adults.

BACKGROUND: The Omicron wave of Coronavirus disease 2019 (COVID-19) remains the dominant strain worldwide. The studies of nutritional status in geriatric people with COVID-19 Omicron variant are limited. Thus, the aim of this study was to investigate the incidence of poor nutritional status among Omicron infected older patients, and to explore the correlation between the nutritional status and the severity of Omicron infection in older patients. METHODS: This is a retrospective cross-sectional study. According to the clinical symptoms, patients were divided into two groups: mild and moderate to severe. Mini Nutritional Assessment short-form (MNA-SF) was conducted when patients were admitted and poor nutritional status was defined as MNA-SF score of 0-11. The inflammatory markers including neutrophil lymphocyte ratio (NLR), platelet lymphocyte ratio (PLR) and systemic inflammatory index (SII) were calculated and compared between two groups. RESULTS: Total of 324 patients were enrolled, with median [interquartile range (IQR)] age of 73 (17) years. Overall, 241 cases were mild, 83 cases were moderate to severe at the time of diagnosis and that 54.3% of patients had poor nutritional status. Patients with poor nutritional status were found to be older (P < 0.001) and less vaccinated (P < 0.001), with a longer virus shedding duration (P = 0.022), more comorbidities (≥ 2) (P = 0.004) and higher value of NLR (P < 0.001), PLR (P < 0.001) and SII (P = 0.012). Vaccination, cycle threshold value in ORF1ab gene (OR CT value) and female, higher MNA-SF score was negatively connected with probability of moderate to severe infection. For every 1 score increase in MNA-SF, the odds ratio of moderate to severe infection decreased by 14.8% [adjusted odds ratio (aOR), 0.852; 95% confidence interval (CI): 0.734-0.988; P = 0.034]. CONCLUSIONS: Older patients with poor nutritional status are more likely to develop moderate to severe Omicron infection.

Result of a Pilot External Quality Assessment Scheme for Clinical Diagnosis of Inherited Metabolic Disorders in China.

BACKGROUND: We aimed to evaluate the diagnostic capabilities of Chinese laboratories for inherited metabolic disorders (IMDs) using gas chromatography-mass spectrometry (GC-MS) on urine samples. Meanwhile, based on the result of the pilot external quality assessment (EQA) scheme, we hope to establish a standardized and reliable procedure for future EQA practice. METHODS: We recruited laboratories that participated in the EQA of quantitative analysis of urinary organic acids with GC-MS before joining the surveys. In each survey, a set of five real urine samples was distributed to each participant. The participants should analyze the sample by GC-MS and report the "analytical result", "the most likely diagnosis", and "recommendation for further tests" to the NCCL before the deadline. RESULTS: A total of 21 laboratories participated in the scheme. The pass rates were 94.4% in 2020 and 89.5% in 2021. For all eight IMDs tested, the analytical proficiency rates ranged from 84.7% - 100%, and the interpretational performance rate ranged from 88.2% - 97.0%. The performance on hyperphenylalaninemia (HPA), 3-methylcrotonyl-CoA carboxylase deficiency (MCCD), and ethylmalonic encephalopathy (EE) samples were not satisfactory. CONCLUSIONS: In general, the participants of this pilot EQA scheme are equipped with the basic capability for qualitative organic acid analysis and interpretation of the results. Limited by the small size of laboratories and samples involved, this activity could not fully reflect the state of clinical practice of Chinese laboratories. NCCL will improve the EQA scheme and implement more EQA activities in the future.

The relationship between family resilience, post-traumatic growth, and caregiver burden among family caregivers of stroke survivors: a cross-sectional study.

The study aimed to explore the relationship between family resilience, post-traumatic growth(PTG), and caregiver burden among family caregivers of stroke survivors. Researchers conducted a cross-sectional study to recruit 253 family caregivers of stroke survivors from a public hospital in Shandong Province, China. Caregivers completed sociodemographic information, the Shortened Chinese Version of the Family Resilience Assessment Scale, the Post-traumatic Growth Inventory, and the Zarit Caregiver Burden Interview. We used Amos 24.0 to construct structural equation models and examine the mediating effects of stroke survivors' post-traumatic growth. Family resilience was positively associated with post-traumatic growth, and both family resilience and post-traumatic growth were negatively associated with caregiver burden. Post-traumatic growth partially mediated the relationship between family resilience and caregiver burden, and the mediating effect accounted for 21.27% of the total effect. Targeted interventions should address family resilience and post-traumatic growth as protective factors of caregiver burden.

Noninvasive biomarkers for lupus nephritis.

Lupus nephritis (LN) is one of the most severe clinical manifestations of systemic lupus erythematosus (SLE). Notably, the clinical manifestations of LN are not always consistent with the histopathological findings. Therefore, the diagnosis and activity monitoring of this disease are challenging and largely depend on invasive renal biopsy. Renal biopsy has side effects and is associated with the risk of bleeding and infection. There is a growing interest in the development of novel noninvasive biomarkers for LN. In this review, we summarize most of the LN biomarkers discovered so far by correlating current knowledge with future perspectives. These biomarkers fundamentally reflect the biological processes of kidney damage and repair during disease. Furthermore, this review highlights the role of urinary cell phenotype detection in the diagnosis, monitoring, and treatment of LN and summarizes the limitations and countermeasures of this test.

Integrating Molecular Biology and Network Pharmacology to Analyze the Antidepressant Mechanism of Glycyrrhizaglabra.

INTRODUCTION: Antidepressants have adverse effects and induce drug resistance when used excessively or frequently. Therefore, adjuvants are needed to reduce the use of antidepressants during treatment. Traditional Chinese medicine (TCM) is an important adjunctive approach to depression with safety, environmental protection, and low toxicity. Glycyrrhizaglabra (licorice, GG) is a plant commonly used in various herbal remedies. METHOD: We investigated the antidepressant activity of GG, its active constituents, and potential depression-related targets. We combined animal behavioral and molecular biological assays with network pharmacology to analyze the antidepressant mechanism of GG. GG extracts reversed lipopolysaccharide (LPS)-induced depression-like behavior in behavioral tests. We selected 56 active compounds and 695 target compounds of licorice from TCMSP. The PPI network screened 80 core targets for enrichment analysis. It shows that GG significantly affected neurodegeneration pathways, neuroactive ligand-receptor interaction, cAMP signaling pathway, serotonergic synapse, dopaminergic synapse, and MAPK signaling pathway. RESULT: Mechanistic studies showed that GG reduced IL-1ß, IL-6, and TNF-α levels, 5-HTRA1 expression, and GSK3ß phosphorylation in mouse hippocampus. It also increased BDNF and DRD1 expression and CREB and ERK1/2 phosphorylation. CONCLUSION: It shows that GG acted on these proteins to affect multiple pathways that mediate the pathogenesis of depression.

Invasive Fusarium solani infection diagnosed by traditional microbial detection methods and metagenomic next-generation sequencing in a pediatric patient: a case report and literature review.

Fusarium solani, as an opportunistic pathogen, can infect individuals with immunosuppression, neutropenia, hematopoietic stem cell transplantation (HSCT), or other high-risk factors, leading to invasive or localized infections. Particularly in patients following allogeneic HSCT, Fusarium solani is more likely to cause invasive or disseminated infections. This study focuses on a pediatric patient who underwent HSCT for severe aplastic anemia. Although initial blood cultures were negative, an abnormality was detected in the 1,3-ß-D-glucan test (G test) post-transplantation. To determine the causative agent, blood samples were subjected to metagenomic next-generation sequencing (mNGS) and blood cultures simultaneously. Surprisingly, the results of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and mNGS differed slightly, with mNGS identifying Nectria haematonectria, while MALDI-TOF MS based on culture showed Fusarium solani. To clarify the results, Sanger sequencing was performed for further detection, and the results were consistent with those of MALDI-TOF MS. Since the accuracy of Sanger sequencing is higher than that of mNGS, the diagnosis was revised to invasive Fusarium solani infection. With advancements in technology, various detection methods for invasive fungi have been developed in recent years, such as mNGS, which has high sensitivity. While traditional methods may be time-consuming, they are important due to their high specificity. Therefore, in clinical practice, it is essential to utilize both traditional and novel detection methods in a complementary manner to enhance the diagnosis of invasive fungal infections.

Corrigendum: Therapeutic strategies targeting folate receptor α for ovarian cancer.

[This corrects the article DOI: 10.3389/fimmu.2023.1254532.].

miR-539-5p targets BMP2 to regulate Treg activation in B-cell acute lymphoblastic leukemia through TGF-ß/Smads/MAPK.

MicroRNAs (mRNAs) were believed to play an important role in cancers, and this study aimed to explore the mechanism of miRNA regulating Treg in B-cell acute lymphoblastic leukemia (B-ALL). Firstly, the differentially expressed miRNAs and target genes significantly associated with Tregs were screened out by high-throughput sequencing, and their enrichment pathways were analyzed. The binding relationship between miRNA and target genes was further verified, and the effects of miRNA on the proliferation and apoptosis of B-ALL Nalm-6 cells and Treg activation were analyzed. Results showed that differentially expressed miR-539-5p was significantly under-expressed, and its target gene BMP2 was significantly over-expressed in B-ALL, and significantly enriched in the TGF-ß1 pathway. In addition, both miR-539-5p and BMP2 were significantly correlated with Treg activity in B-ALL. In vitro experiments further confirmed that miR-539-5p could directly target BMP2. The low expression of miR-539-5p in B-ALL significantly promoted BMP2 expression to promote the proliferation and inhibit apoptosis of Nalm-6 cells. Furthermore, the high expression of BMP2 in B-ALL could cooperate with TGF-ß1 to promote the activation of human CD4+CD25-T cells to Treg, and significantly activate the TGF-ß/Smads/MAPK pathway. In vivo experiments also confirmed that overexpression of miR-539-5p significantly inhibited BMP2 to suppress Treg activation and Smad1 and Smad2 phosphorylation, and finally inhibit the B-ALL process. In conclusion, miR-539-5p was significantly under-expressed in B-ALL and could target BMP2 to promote its expression, and the overexpressed BMP2 further promoted Treg activation in B-ALL by regulating TGF-ß/Smads/MAPK pathway.

Chloramphenicol Binding Sites of Acinetobacter baumannii Chloramphenicol Acetyltransferase CatB8.

Acinetobacter baumannii is a multidrug-resistant pathogen that has become one of the most challenging pathogens in global healthcare. Several antibiotic-resistant genes, including catB8, have been identified in the A. baumannii genome. CatB8 protein, one of the chloramphenicol acetyltransferases (Cats), is encoded by the catB8 gene. Cats can convert chloramphenicol (chl) to 3-acetyl-chl, leading to bacterial resistance to chl. Here, we present the high-resolution cocrystal structure of CatB8 with chl. The structure that we resolved showed that each monomer of CatB8 binds to four chl molecules, while its homologous protein only binds to one chl molecule. One of the newly discovered chl binding site overlaps with the site of another substrate, acetyl-CoA. Through structure-based biochemical analyses, we identified key residues for chl recruiting and acetylation of chl in CatB8. Our work is of significant importance for understanding the drug resistance of A. baumannii and the effectiveness of antibiotic treatment.

Ultrasound-assisted complex enzyme extraction, structural characterization, and biological activity of polysaccharides from Ligustrum robustum.

Ligustrum robustum is one of the traditional teas in China with a long history of drinking and medicinal use. Through Response surface optimization, the yield of polysaccharides extracted by ultrasonic-assisted complex enzyme (UAE-EN) method was increased to 14.10 ±â€¯0.56 %. Neutral homogeneous polysaccharide (LRNP) and acidic homogeneous polysaccharide (LRAP-1, LRAP-2, LRAP-3) from L. robustum were purified. The molecular weights of them were 5894, 4256, 4621 and 3915 Da. LRNP was composed of glucose (Glc), galactose (Gal), arabinose (Ara) with molar percentage of 24.97, 42.38 and 30.80. Structure analysis revealed that the backbone of LRNP consisted of 1,5-linked α-Araf, 1,4-linked ß-Galp, 1,6-linked ß-Galp, and 1,4-linked ß-Glcp with the branches of 1,2-linked α-Araf, 1,3-linked α-Araf, 1,3-linked ß-Glcp and 1,6-linked ß-Galp residues, some terminal residues of α-Araf, ß-Glcp and α-Galp were also included. In vitro experiments showed that the four polysaccharides possessed excellent antioxidant, antitumor and hypoglycemic activities. LRNP possessed the protective effect against oxidative stress. The studies provide a basis for further exploitation of L. robustum.

Serotype, antibiotic susceptibility and whole-genome characterization of Streptococcus pneumoniae in all age groups living in Southwest China during 2018-2022.

Background: Streptococcus pneumoniae is a common pathogen that colonizes the human upper respiratory tract, causing high morbidity and mortality worldwide. This study aimed to investigate the prevalence status of S. pneumoniae isolated from patients of all ages in Southwest China, including serotype, antibiotic susceptibility and other molecular characteristics, to provide a basis for clinical antibiotic usage and vaccine development. Methods: This study was conducted from January 2018 to March 2022 at West China Hospital, West China Second University Hospital, First People's Hospital of Longquanyi District (West China Longquan Hospital), Meishan Women and Children's Hospital (Alliance Hospital of West China Second University Hospital) and Chengdu Jinjiang Hospital for Women and Children Health. Demographic and clinical characteristics of 263 pneumococcal disease (PD) all-age patients were collected and analyzed. The serotypes, sequence types (STs), and antibiotic resistance of the strains were determined by next-generation sequencing, sequence analysis and the microdilution broth method. Results: The most common pneumococcal serotypes were 19F (17.87%), 19A (11.41%), 3 (8.75%), 23F (6.46%) and 6A (5.70%). Coverage rates for PCV10, PCV13, PCV15, PCV20 and PCV24 were 36.12, 61.98, 61.98, 63.12 and 64.26%, respectively. Prevalent STs were ST271 (12.55%), ST320 (11.79%), ST90 (4.18%), ST876 (4.18%) and ST11972 (3.42%). Penicillin-resistant S. pneumoniae (PRSP) accounted for 82.35 and 1.22% of meningitis and nonmeningitis PD cases, respectively. Resistance genes msrD (32.7%), mefA (32.7%), ermB (95.8%), tetM (97.3%) and catTC (7.6%) were found among 263 isolates. Most isolates showed high resistance to erythromycin (96.96%) and tetracycline (79.85%), with more than half being resistant to SXT (58.94%). A few isolates were resistant to AMX (9.89%), CTX (11.03%), MEN (9.13%), OFX (1.14%), LVX (1.14%) and MXF (0.38%). All isolates were susceptible to vancomycin and linezolid. Conclusion: Our study provides reliable information, including the prevalence, molecular characterization and antimicrobial resistance of S. pneumoniae isolates causing pneumococcal diseases in Southwest China. The findings contribute to informed and clinical policy decisions for prevention and treatment.

Immunoinformatics Prediction and Protective Efficacy of Vaccine Candidate PiuA-PlyD4 Against Streptococcus Pneumoniae.

Purpose: This study was designed to evaluate the immune protective efficacy of the novel Streptococcus pneumoniae (S. pneumoniae) protein vaccine PiuA-PlyD4 through immunoinformatics prediction and in vitro and in vivo experiments. Methods: In this study, we conducted immunoinformatics prediction and protection analysis on the fusion protein PiuA-PlyD4. The epitope composition of the vaccine was analyzed based on the prediction of B-cell and helper T-cell epitopes. Meanwhile, the molecular docking of PiuA and TLR2/4 was simulated. After immunizing C57BL/6 mice with the prepared vaccine, the biological safety, immunogenicity and conservation were evaluated. By constructing different infection models and from the aspects of adhesion inhibition and cytokines, the protective effect of the fusion protein vaccine PiuA-PlyD4 on S. pneumoniae infection was explored. Results: PiuA-PlyD4 has abundant B-cell and helper T-cell epitopes and shows a high antigenicity score and structural stability. Molecular docking analysis suggested the potential interaction between PiuA and TLR2/4. The specific antibody titer of fusion protein antiserum was as high as (7.81±2.32) ×105. The protective effect of the immunized mice on nasal and lung colonization was significantly better than that of the control group, and the survival rate against S. pneumoniae infection of serotype 3 reached 50%. Cytokine detection showed that the humoral immune response, Th1, Th2 and Th17 cellular immune pathways were all involved in the process. Conclusion: The study indicates that PiuA-PlyD4, whether the results are predicted by immunoinformatics or experimentally validated in vivo and in vitro, has good immunogenicity and immunoreactivity and can provide effective protection against S. pneumoniae infection. Therefore, it can be considered a promising prophylactic vaccine candidate for S. pneumoniae.