Application of MALDI-TOF mass spectrometry for identification of Nocardia species.

BACKGROUND: Nocardiosis, despite its rarity and underreporting, is significant due to its severe impact, characterized by high morbidity and mortality rates. The development of a precise, reliable, rapid, and straightforward technique for identifying the pathogenic agent in clinical specimens is crucial to reduce fatality rates and facilitate timely antimicrobial treatment. In this study, we aimed to identify Nocardia spp. in clinical isolates, using MALDI-TOF MS as the primary method, with molecular methods as the gold standard. Clinical Nocardia isolates were identified using 16S rRNA/hsp65/gyrB/secA1/rpoB gene sequencing. Identification performance of the Bruker MALDI Biotyper 3.1 (V09.0.0.0_8468) and MBT Compass 4.1 (V11.0.0.0_10833) for Nocardia identification was evaluated. RESULTS: Seventy-six Nocardia isolates were classified into 12 species through gene sequencing. The MALDI Biotyper 3.1 (V09.0.0.0_8468) achieved 100% genus-level accuracy and 84.2% species accuracy (64/76). The MBT Compass 4.1 with the BDAL Database (V11.0.0.0_10833) improved species identification to 98.7% (75/76). The updated database enhanced species level identification with scores > 1.7, increasing from 77.6% (59/76) to 94.7% (72/76), a significant improvement (P = 0.001). The new and simplified extraction increased the proportion of strains identified to the species level with scores > 1.7 from 62.0% (18/29) to 86.2% (25/29) (P = 0.016). An in-house library construction ensured accurate species identification for all isolates. CONCLUSIONS: The Bruker mass spectrometer can accurately identify Nocardia species, albeit with some variations observed between different database versions. The MALDI Biotyper 3.1 (V09.0.0.0_8468) has limitations in identifying Nocardia brasiliensis, with some strains only identifiable to the genus level. MBT Compass 4.1 (V11.0.0.0_10833) effectively addresses this shortfall, improving species identification accuracy to 98.7%, and offering quick and reliable identification of Nocardia. Both database versions incorrectly identified the clinically less common Nocardia sputorum as Nocardia araoensis. For laboratories that have not upgraded their databases and are unable to achieve satisfactory identification results for Nocardia, employing the new and simplified extraction method can provide a degree of improvement in identification outcomes.

Relationship between virulence and carbapenem resistance phenotype of Klebsiella pneumoniae from blood infection: identification of a carbapenem-resistant and hypervirulent strain. / è¡€æ¶²æ„ŸæŸ“æ¥æºè‚ºç‚Žå ‹é›·ä¼¯èŒæ¯’åŠ›ä¸Žç¢³é’éœ‰çƒ¯ç±»è€è¯è¡¨åž‹çš„å ³ç³»åŠç¢³é’éœ‰çƒ¯ç±»è€è¯é«˜æ¯’åŠ›èŒæ ªçš„é‰´å®š.

OBJECTIVES: To investigate the relationship between the virulence and the carbapenem resistance phenotype of Klebsiella pneumoniae from blood infection, and to identify carbapenem-resistant and hypervirulent Klebsiella pneumoniae (CR-HVKP)strains. METHODS: A total of 192 Klebsiella pneumoniae strains were isolated from blood culture of patients with bloodstream infections from 2016 to 2019, of which 96 isolates were carbapenem-resistant Klebsiella pneumoniae (CRKP) and 96 were carbapenem-sensitive Klebsiella pneumoniae (CSKP). The drug susceptibility was detected by VITEK-2 automatic microbial analyzer; carbapenemase genes, virulence genes and capsule typing were detected by polymerase chain reaction; the high viscosity phenotype of strains was detected by string test, and the genome characteristics of CR-HVKP were detected by whole genome sequencing. Serum killing and biofilm formation test were used to further verify the virulence of CR-HVKP. RESULTS: There were significant differences in drug resistance to common antibiotics, except for minocycline between CSKP and CRKP isolates (all P<0.05). 92 out of 96 CRKP isolates carried carbapenemase genes, mainly blaKPC-2. The string tests were positive in 4 isolates of CRKP and 36 isolates of CSKP (P<0.05). The detection rates of virulence genes Kfu, aerobictin, iutA, ybtS, rmpA, magA, allS, and capsule antigen K1 and K2 in CSKP group were significantly higher than those in CRKP group (all P<0.05). One HVKP strain was detected in the CRKP group (CR-HVKP) and 36 HVKP was detected in the CSKP group (P<0.05). The CR-HVKP strain belonged to the MLST412, serotype K57, expressed iutA, entB, mrkD, fimH, and rmpA virulence genes, and showed strong biofilm formation and significantly increased serum resistance. Whole genome sequencing results showed that this CR-HVKP isolate carried blaSHV-145, blaTEM-1, blaCTX-M-3, fosA6, oqxA5, oqxB26, and aac(3)-IId resistance genes, accompanied by abnormalities in outer membrane protein K (OmpK) 35 and OmpK36. CONCLUSIONS: The drug resistance of CRKP is significantly higher than that of CSKP, while CRKP carrying fewer virulence genes in both number and types compared to CSKP. A new MLST type of carbapenem-resistant and hypervirulent Klebsiella pneumoniae strain has been detected, which requires clinical awareness and epidemiological monitoring.

Associations of air pollutants and related metabolites with preterm birth during pregnancy.

OBJECTIVE: This study aimed to investigate the influence of exposure to ambient fine particulate matter (PM2.5) and its components during pregnancy on the prevalence of preterm birth (PTB). Additionally, we sought to identify the susceptible exposure window. Furthermore, we explored the potential mediating role of blood analysis and a comprehensive metabolic panel in the association between pollutant exposure and PTB incidence. METHODS: This birth cohort study recruited 139 participants with PTB outcomes and 1713 controls from Fujian Maternal and Child Health Hospital between January 2021 and June 2023. Sociodemographic characteristics and clinical treatment data during participants' first pregnancies were collected. The exposure levels to pollutants during pregnancy were estimated via a combined geographic-statistical model utilising satellite remote sensing data. The distributional lag nonlinear modelling was employed to assess associations between pollutant exposure during pregnancy and the prevalence of PTB. Weighted quantile regression was used to identify key components associated with PM2.5 and PTB during pregnancy. Additionally, a mediating effect analysis was conducted to evaluate the role of blood analysis. The metabolic profile was used to screen for differentially abundant metabolites associated with PTB and explore their relative expression in relation to air pollutants and PTB incidence. RESULTS: Following the adjustment for potential confounding variables, the mean weekly susceptibility windows for PM2.5 were identified as 7-10, 16-19, and 22-28 weeks; 8-10, and 15-19 weeks for inorganic sulfate; 6-10, and 15-28 weeks for nitrate; 6-12, and 15-28 weeks for ammonium (NH4+); and 7-9, 18-20, and 22-36 weeks for organic matter. During mixed exposure to PM2.5 components, the key component is NH4+. In the mixed exposure to PM2.5 components, NH4+ emerged as a key contributor. The results of the mediation analysis revealed that haemoglobin played a mediating role, accounting for 21.53 % of the association between exposure to environmental pollutants and the prevalence of PTB. It is noteworthy that, no mediating effects were observed for the other variables. Furthermore, non-targeted metabolomics identified 17 metabolites associated with PTB. Among these factors, hydrogen phosphate may impact metabolic pathways such as oxidative phosphorylation, influencing the risk of PTB. The interplay between environmental pollutants and metabolites, particularly through oxidative phosphorylation pathways, may contribute to PTB incidence. CONCLUSIONS: The evidence indicates that exposure to PM2.5 and its components during pregnancy were a significant risk factor for PTB. Notably, specific weekly exposure windows were identified for pollutants during pregnancy. Among the PM2.5 components, NH4+ exhibited the most substantial weight in the association analysis between exposure to the mixture of components and PTB. Furthermore, our mediation analysis revealed that haemoglobin serves as a partial mediator in the relationship between exposure to pollutants during pregnancy and the prevalence of PTB. Additionally, maternal serum metabolic profiles differed between the preterm and control groups. Notably, a combined effect involving hydrogen phosphate and mixed exposure to PM2.5 fractions further contributed to the development of PTB. Oxidative phosphorylation pathways may play pivotal roles in this intricate association.

Long Noncoding RNA NR_030777 Alleviates Cobalt Nanoparticles-Induced Neurodegenerative Damage by Promoting Autophagosome-Lysosome Fusion.

Potential exposure to cobalt nanoparticles (CoNPs) occurs in various fields, including hard alloy industrial production, the increasing use of new energy lithium-ion batteries, and millions of patients with metal-on-metal joint prostheses. Evidence from human, animal, and in vitro experiments suggests a close relationship between CoNPs and neurotoxicity. However, a systematic assessment of central nervous system (CNS) impairment due to CoNPs exposure and the underlying molecular mechanisms is lacking. In this study, we found that CoNPs induced neurodegenerative damage both in vivo and in vitro, including cognitive impairment, ß-amyloid deposition and Tau hyperphosphorylation. CoNPs promoted the formation of autophagosomes and impeding autophagosomal-lysosomal fusion in vivo and in vitro, leading to toxic protein accumulation. Moreover, CoNPs exposure reduced the level of transcription factor EB (TFEB) and the abundance of lysosome, causing a blockage in autophagosomal-lysosomal fusion. Interestingly, overexpression of long noncoding RNA NR_030777 mitigated CoNPs-induced neurodegenerative damage in both in vivo and in vitro models. Fluorescence in situ hybridization assay revealed that NR_030777 directly binds and stabilizes TFEB mRNA, alleviating the blockage of autophagosomal-lysosomal fusion and ultimately restoring neurodegeneration induced by CoNPs in vivo and in vitro. In summary, our study demonstrates that autophagic dysfunction is the main toxic mechanism of neurodegeneration upon CoNPs exposure and NR_030777 plays a crucial role in CoNPs-induced autophagic dysfunction. Additionally, the proposed adverse outcome pathway contributes to a better understanding of CNS toxicity assessment of CoNPs.

[Distribution and Drug Resistance Characteristics of Pathogenic Bacteria in the Elderly Population in China in 2021]. / 2021å¹´ä¸­å›½è€å¹´äººç¾¤æ„ŸæŸ“ç— åŽŸèŒåˆ†å¸ƒå’Œè€è¯æ€§ç‰¹å¾.

Objective: To study the distribution and drug resistance characteristics of pathogenic bacteria in the elderly population of China by collecting and analyzing the standardized case data on the pathogens of infections in elderly patients, and to facilitate the establishment of a standardized layered surveillance system for pathogenic bacteria in China. Methods: We collected the case data of elderly patients (≥65 years old) from 62 sentinel hospitals across the country in 2021. Then, we statistically analyzed the data by patient age, their geographical region, the distribution of pathogenic bacteria, and the drug resistance characteristics of main pathogens. Results: A total of 3468 cases from across the country were included in the study. The top three sources of patients were the intensive care unit (13.2%), the department of respiratory medicine (11.2%), and the department of general surgery (8.4%). The top three types of specimens were urine (25.5%), sputum (20.6%), and blood (18.7%). A total of 3468 strains of pathogens were isolated, among which, 78.9% were gram-negative bacteria and 21.1% were gram-positive bacteria. The top five types of bacteria were Escherichia coli (20.9%), Klebsiella pneumoniae (18.3%), Pseudomonas aeruginosa (11.2%), Staphylococcus aureus (9.0%), and Acinetobacter baumannii (7.0%). The isolation rates of common important drug-resistant bacteria were 38.0% for methicillin-resistant Staphylococcus aureus (MRSA), 68.7% for carbapenem-resistant Acinetobacter baumannii (CRAB), and 38.2% for carbapenem-resistant Pseudomonas aeruginosa (CRPA), 20.1% for carbapenem-resistant Klebsiella pneumoniae (CRKP), 5.2% for carbapenem-resistant Escherichia coli (CRECO), and 2.1% for vancomycin-resistant Enterococcus (VRE). There were differences in the isolation rates of CRAB and CRKP in clinical care in the elderly population in seven geographical regions of China (P<0.05). Klebsiella pneumoniae is the most important pathogen in the elderly population ≥85 years old, and the isolation rates of CRKP showed significant differences in different age groups (P<0.05). Conclusion: There are significant differences in the drug resistance of pathogenic bacteria in the elderly populations of different regions and age groups in China. Therefore, monitoring the distribution and drug resistance of pathogenic bacteria in the elderly population and formulating targeted treatment plans according to the characteristics of the specific regions and age groups are of great significance to the improvement in the treatment outcomes and prognosis of the elderly population.

ALKBH5-mediated N6-methyladenosine modification of HO-1 mRNA regulates ferroptosis in cobalt-induced neurodegenerative damage.

The utilization of Cobalt (Co) has surged due to it is critical role in renewable energy technologies and other high-tech applications. Concurrently, the potential health risks associated with Co exposure have raised concerns. Previous studies, including our own, have shown that Co can impair learn and memory functions as an epigenetic hazard, even at low concentrations. In this study, we explore the mechanisms of Co-induced ferroptosis in neurodegenerative damage both in vivo and in vitro, focusing on the epigenetic regulation by N6-methyladenosine (m6A) demethylase alkB homolog 5 (ALKBH5). We identify heme oxygenase-1 (HO-1) as a direct target gene of ALKBH5, playing a crucial role in mitigating Co-induced ferroptosis. ALKBH5 deficiency affects the post-transcriptional regulation of HO-1 through m6A modification, which in turn influences mRNA's stability, intracellular distribution, and alternative splicing, thereby enhancing susceptibility to Co-induced ferroptosis. Additionally, we discuss the potential involvement of heterogeneous nuclear ribonucleoprotein M (hnRNPM) in regulating alternative splicing of HO-1 mRNA, potentially mediated by m6A modifications. This study provides new epigenetic insights into the post-transcriptional regulatory mechanisms involved in Co-induced ferroptosis and highlights the broader implications of environmental hazards in neurodegenerative damage.

Association between maternal lipid profiles and lipid ratios in early to middle pregnancy as well as their dynamic changes and gestational diabetes mellitus.

BACKGROUND: Unfavourable lipid and glucose levels may play a crucial role in the pathogenesis of gestational diabetes mellitus (GDM). However, there is a lack of prospective studies on the relationship between lipid profiles, lipid ratios and GDM during pregnancy. AIMS: To prospectively investigate the relationship between lipid profile and lipid ratios in early and mid-pregnancy and their pattern of change from early to mid-pregnancy and the risk of GDM. METHODS: This nested case-control study was based on maternal and child healthcare hospitals from Fujian Province, China. We included pregnant women who delivered in the hospital from January 2021 to June 2023. Lipid profiles (TC, TG, ApoA1, ApoB, HDL-c, LDL-c) and fasting glucose were measured before 14 weeks of gestation and between 20 and 28 weeks of gestation, and lipid ratios (triglyceride glucose index, TG/HDL-c and TC/HDL-c) was constructed. Logistic regression was used to assess the relationship between lipid profile, lipid ratios and GDM. RESULTS: Of 1586 pregnant women, 741 were diagnosed with GDM. After adjusting for potential confounders, TG, ApoA1, ApoB, LDL-c, triglyceride glucose index, TG/HDL-c, and TC/HDL-c in early pregnancy were positively associated with the risk of GDM (odds ratios [95% CI] for extreme interquartile comparisons were 2.040 (1.468-2.843), 1.506 (1.091-2.082), 1.529 (1.110-2.107), 1.504 (1.086-2.086), 1.952 (1.398-2.731), 2.127 (1.526-2.971), and 2.370 (1.700-3.312), all trend P < 0.05). HDL-c was negatively associated with the risk of GDM (0.639: 0.459-0.889, trend P all less than 0.05). Similarly, in mid-pregnancy, lower levels of HDL-c, higher levels of triglyceride glucose index, TG/HDL-c ratio, and TC/HDL-c ratio were associated with increased risk of GDM (all trends P < 0.05). Stably high levels (both ≥ median for early and mid-pregnancy) of triglyceride glucose index, TG/HDL-c and TC/HDL-c were associated with increased risk of GDM (OR [95% CI]: 2.369 (1.438-3.940), 1.588 (1.077-2.341), 1.921 (1.309-2.829), respectively). The opposite was true for HDL-c, where stable high levels were negatively associated with GDM risk (OR [95% CI]: 0.599 (0.405-0.883)). CONCLUSION: Increases in triglyceride glucose index, TG/HDL-c ratio, and TC/HDL-c ratio in early and mid-pregnancy, as well as their stable high levels from early to mid-pregnancy, are associated with a higher risk of GDM. In contrast, increased levels of HDL-c, both in early and mid-pregnancy, and their stable high levels from early to mid-pregnancy were associated with a lower risk of GDM. That highlighted their possible clinical relevance in identifying those at high risk of GDM.

Lactiplantibacillus plantarum N4 ameliorates lipid metabolism and gut microbiota structure in high fat diet-fed rats.

Lowing blood lipid levels with probiotics has good application prospects. This study aimed to isolate probiotics with hypolipidemic efficacy from homemade na dish and investigate their mechanism of action. In vitro experiments were conducted to determine the cholesterol-lowering ability of five isolates, with results showing that Lactiplantibacillus plantarum N4 exhibited a high cholesterol-lowering rate of 50.27% and significant resistance to acid (87%), bile salt (51.97%), and pepsin (88.28%) in simulated gastrointestinal fluids, indicating promising application prospects for the use of probiotics in lowering blood lipids. The findings from the in vivo experiment demonstrated that the administration of N4 effectively attenuated lipid droplet accumulation and inflammatory cell infiltration in the body weight and liver of hyperlipidemic rats, leading to restoration of liver tissue morphology and structure, as well as improvement in lipid and liver biochemical parameters. 16S analysis indicated that the oral administration of N4 led to significant alterations in the relative abundance of various genera, including Sutterella, Bacteroides, Clostridium, and Ruminococcus, in the gut microbiota of hyperlipidemia rats. Additionally, fecal metabolomic analysis identified a total of 78 metabolites following N4 intervention, with carboxylic acids and their derivatives being the predominant compounds detected. The transcriptomic analysis revealed 156 genes with differential expression following N4 intervention, leading to the identification of 171 metabolic pathways through Kyoto Encyclopedia of Genes and Genomes enrichment analysis. Notably, the glutathione metabolism pathway, PPAR signaling pathway, and bile secretion pathway emerged as the primary enrichment pathways. The findings from a comprehensive multi-omics analysis indicate that N4 influences lipid metabolism and diminishes lipid levels in hyperlipidemic rats through modulation of fumaric acid and γ-aminobutyric acid concentrations, as well as glutathione and other metabolic pathways in the intestinal tract, derived from both the gut microbiota and the host liver. This research offers valuable insights into the therapeutic potential of probiotics for managing lipid metabolism disorders and their utilization in the development of functional foods.

Combined effects of cadmium and simulated acid rain on soil microbial communities in the early cultivation of Populus beijingensis seedlings.

The combined cadmium (Cd) and acid rain pollution poses a significant threat to the global ecological environment. Previous studies on the combined adverse effects have predominantly focused on the aboveground plant physiological responses, with limited reports on the microbial response in the rhizosphere soil. This study employed Populus beijingensis seedlings and potting experiments to simulate the impacts of combined mild acid rain (pH=4.5, MA) or highly strong acid rain (pH=3.0, HA), and soil Cd pollution on the composition and diversity of microbial communities, as well as the physiochemical properties in the rhizosphere soil. The results showed that Cd decreased the content of inorganic nitrogen, resulting in an overall decrease of 49.10 % and 46.67 % in ammonium nitrogen and nitrate nitrogen, respectively. Conversely, acid rain was found to elevate the content of total potassium and soil organic carbon by 4.68 %-6.18 % and 8.64-19.16 %, respectively. Additionally, simulated acid rain was observed to decrease the pH level by 0.29-0.35, while Cd increased the pH level by 0.11. Moreover, Cd alone reduced the rhizosphere bacterial diversity, however, when combined with acid rain, regardless of its intensity, Cd was observed to increase the diversity. Fungal diversity was not influenced by the acid rain, but Cd increased fungal diversity to some extend under HA as observed in bacterial diversity. In addition, composition of the rhizosphere bacterial community was primarily influenced by the inorganic nitrogen components, while the fungal community was driven mainly by soil pH. Furthermore, "Metabolism" was emerged as the most significant bacterial function, which was markedly affected by the combined pollution, while Cd pollution led to a shift from symbiotroph to other trophic types for fungi. These findings suggest that simulated acid rain has a mitigating effect on the diversity of rhizosphere bacteria affected by Cd pollution, and also alters the trophic type of these microorganisms. This can be attributed to the acid rain-induced direct acidic environment, as well as the indirect changes in the availability or sources of carbon, nitrogen, or potassium.

The association between blood pressure variability and renal damage in patients with primary aldosteronism.

This research examines the association between blood pressure variability (BPV) and renal damage in a cohort of 129 primary aldosteronism (PA) patients, employing ambulatory blood pressure monitoring (ABPM) for comparative analysis with individuals diagnosed with essential hypertension (EH). The study reveals that PA patients exhibited significantly elevated levels of cystatin C and urine microalbumin/creatinine ratio (UACR). Additionally, a higher prevalence of non-dipping blood pressure patterns in PA patients suggests an increased risk of circadian blood pressure regulation disturbances. Notably, while most BPV indices were comparable between the two groups, the standard deviation of 24-h weighted diastolic blood pressure was markedly lower in the PA cohort, distinguishing it as a unique variable. Through multiple linear regression analysis, the duration of hypertension, angiotensin II concentrations, and daytime systolic blood pressure standard deviation emerged as significant determinants of estimated glomerular filtration rate (eGFR) in PA patients. Furthermore, UACR was significantly influenced by variables including the 24-h weighted standard deviation (wSD) of systolic BP, glycosylated hemoglobin levels, nocturnal systolic BP peaks, aldosterone-renin ratio (ARR), and total cholesterol, with the most pronounced association observed with the 24-h wSD of systolic BP (ß = 0.383).The study also found significant correlations between the 24-h wSD of systolic BP, ARR, HbA1c, serum potassium levels, and 24-h urinary microalbumin, underscoring the critical role of the 24-h wSD of systolic BP (ß = 0.267). These findings underscore the imperative of an integrated management strategy for PA, addressing the intricate interconnections among metabolic abnormalities, blood pressure variability, and renal health outcomes.

VGluT2 neuron subtypes in the paraventricular thalamic nucleus regulate depression in paraquat-induced Parkinson's disease.

Parkinson's disease (PD) is a prevalent neurodegenerative disease and approximately one third of patients with PD are estimated to experience depression. Paraquat (PQ) is the most widely used herbicide worldwide and PQ exposure is reported to induce PD with depression. However, the specific brain region and neural networks underlying the etiology of depression in PD, especially in the PQ-induced model, have not yet been elucidated. Here, we report that the VGluT2-positive glutamatergic neurons in the paraventricular thalamic nucleus (PVT) promote depression in the PQ-induced PD mouse model. Our results show that PVTVGluT2 neurons are activated by PQ and their activation increases the susceptibility to depression in PD mice. Conversely, inhibition of PVTVGluT2 neurons reversed the depressive-behavioral changes induced by PQ. Similar to the effects of intervention the soma of PVTVGluT2 neurons, stimulation of their projections into the central amygdaloid nucleus (CeA) also strongly influenced depression in PD mice. PQ induced malfunctioning of the glutamate system and changes in the dendritic and synaptic morphology in the CeA through its role on PVTVGluT2 neuronal activation. In summary, our results demonstrate that PVTVGluT2 neurons are key neuronal subtypes for depression in PQ-induced PD and promote depression processes through the PVTVGluT2-CeA pathway.

ALKBH5 targets ACSL4 mRNA stability to modulate ferroptosis in hyperbilirubinemia-induced brain damage.

Bilirubin-induced brain damage is a serious clinical consequence of hyperbilirubinemia, yet the underlying molecular mechanisms remain largely unknown. Ferroptosis, an iron-dependent cell death, is characterized by iron overload and lipid peroxidation. Here, we report a novel regulatory mechanism of demethylase AlkB homolog 5 (ALKBH5) in acyl-coenzyme A synthetase long-chain family member 4 (ACSL4)-mediated ferroptosis in hyperbilirubinemia. Hyperdifferential PC12 cells and newborn Sprague-Dawley rats were used to establish in vitro and in vivo hyperbilirubinemia models, respectively. Proteomics, coupled with bioinformatics analysis, first suggested the important role of ferroptosis in hyperbilirubinemia-induced brain damage. In vitro experiments showed that ferroptosis is activated in hyperbilirubinemia, and ferroptosis inhibitors (desferrioxamine and ferrostatin-1) treatment effectively alleviates hyperbilirubinemia-induced oxidative damage. Notably, we observed that the ferroptosis in hyperbilirubinemia was regulated by m6A modification through the downregulation of ALKBH5 expression. MeRIP-seq and RIP-seq showed that ALKBH5 may trigger hyperbilirubinemia ferroptosis by stabilizing ACSL4 mRNA via m6A modification. Further, hyperbilirubinemia-induced oxidative damage was alleviated through ACSL4 genetic knockdown or rosiglitazone-mediated chemical repression but was exacerbated by ACSL4 overexpression. Mechanistically, ALKBH5 promotes ACSL4 mRNA stability and ferroptosis by combining the 669 and 2015 m6A modified sites within 3' UTR of ACSL4 mRNA. Our findings unveil a novel molecular mechanism of ferroptosis and suggest that m6A-dependent ferroptosis could be an underlying clinical target for the therapy of hyperbilirubinemia.

Synthesis of phenol formaldehyde resin (PFR) based fluorescence resonance energy transfer (FRET) composites for double channel detection of latent fingerprints.

A reversible two-channel fluorescent nanocomposite with fluorescence resonance energy transfer (FRET) effect was designed for the development, analysis, and characterization of latent fingerprints (LFPs). For the construction of the FRET probe, a core of mesoporous silicas (MSNs) were used to encapsulate the organic dye rhodamine 6G (RhD-6) as an acceptor, while green-emitting monodisperse phenolic resin nanoparticles (PFR NPs) were selected as a donor. The up-conversion material (UC) of NaYF4:Yb,Er was synthesized using a simple hydrothermal method, and the MSNs-RhD-6/PFR (PRM) was electrostatically adsorbed onto the UC nanoparticles using a layer-by-layer method to obtain MSNs-RhD-6/PFR-UC (PMU). Compared to ordinary single-channel materials, PMU can be excited by different light sources (365 nm UV/980 nm laser) and its fluorescence can be reversibly switched between yellow and green, demonstrating excellent light reversibility. The PMU composites were successfully used to visualize and detect LFPs on various substrate surfaces using a simple powder coating method. Due to the existing FRET effect and dual-channel characteristics, this composite material displays excellent contrast, outperforming commercially available products for wider applicability. Even on complex backgrounds and after aging or washing treatments, it still clearly recognizes fingerprints in first-, second-, and third-level details, showing its great potential in latent fingerprint detection.

Prevalence, genetic and clinical characteristics in first-degree relatives of patients with familial cerebral cavernous malformations in China.

OBJECTIVE: This study aims to investigate the prevalence of familial cerebral cavernous malformations (FCCMs) in first-degree relatives (FDRs) using familial screening, to describe the distribution of initial symptoms, lesion count on cranial MRI and pathogenic gene in patients. METHODS: Patients with multiple CCMs who enrolled from the Treatments and Outcomes of Untreated Cerebral Cavernous Malformations in China database were considered as probands and FDRs were recruited. Cranial MRI was performed to screen the CCMs lesions, and whole-exome sequencing was performed to identify CCM mutations. MRI and genetic screening were combined to diagnose FCCM in FDRs, and the results were presented as prevalence and 95% CIs. The Kaplan-Meier (KM) method was used to calculate the cumulative incidence of FCCM. RESULTS: 33 (76.74%) of the 43 families (110 FDRs) were identified as FCCM (85 FDRs). Receiver operating characteristic analysis revealed three lesions on T2-weighted imaging (T2WI) were the strong indicator for distinguishing probands with FCCM (sensitivity, 87.10%; specificity, 87.50%). Of the 85 FDRs, 31 were diagnosed with FCCM, resulting in a prevalence of 36.5% (26.2%-46.7%). In families with FCCMs, the mutation rates for CCM1, CCM2 and CCM3 were 45.45%, 21.21% and 9.09%, respectively. Furthermore, 53.13% of patients were asymptomatic, 17.19% were intracranial haemorrhage and 9.38% were epilepsy. The mean age of symptom onset analysed by KM was 46.67 (40.56-52.78) years. CONCLUSION: Based on MRI and genetic analysis, the prevalence of CCMs in the FDRs of families with FCCMs in China was 36.5%. Genetic counselling and MRI screening are recommended for FDRs in patients with more than three CCM lesions on T2WI.

Hyperbaric oxygen therapy enhances osteointegration of reimplanted cranial flap by regulating osteogenesis-angiogenesis coupling.

Craniectomy is a lifesaving procedure to alleviate dangerously high intracranial pressure by removing a bone flap from the calvarium. However, the osteointegration of reimplanted bone flap with the existing bone tissue is still a clinical challenge. Hyperbaric oxygen (HBO) therapy has shown efficacy in promoting bone repair and could be a promising treatment for accelerating postoperative recovery. However, the specific cell types that are responsive to HBO treatment are not well understood. In this study, we created a murine model of craniectomy, with reimplantation of the cranial flap after 1 week. The effects of HBO treatment on bone formation and blood vessel formation around reimplanted bone were examined by micro-computed tomography, histological staining, and immunofluorescence staining. Single-cell RNA sequencing (scRNAseq) was utilized to identify key cell subtypes and signaling pathways after HBO treatment. We found that HBO treatment increased bone volume around reimplanted cranial flaps. HBO also increased the volume of Osterix-expressing cells and type H vessels. scRNAseq data showed more mature osteoblasts and endothelial cells, with higher expressions of adhesion and migration-related genes after HBO treatment. Cell-cell interaction analysis revealed a higher expression level of genes between mature osteoblasts and endothelial cells from the angiopoietin 2-integrin α5ß1 pathway. Taken together, HBO therapy promotes the healing process of craniectomy by regulating the crosstalk between vascular endothelial cells and osteogenic cells. These findings provide evidence in a preclinical model that HBO therapy enhances osteointegration by regulating angiogenesis-osteogenesis coupling, providing a scientific basis for utilizing HBO therapy for accelerating postoperative recovery after craniectomy.

Microfluidic particle counter visualizing mucosal antibodies against SARS-CoV-2 in the upper respiratory tract for rapid evaluation of immune protection.

Mucosal antibodies in the upper respiratory tract are the earliest and most critical responders to prevent respiratory infections, providing an indication for the rapid evaluation of immune protection. Here, we report a microfluidic particle counter that directly visualizes mucosal antibody levels in nasal mucus. The mucosal anti-SARS-CoV-2 spike receptor binding domain (RBD) antibodies in nasal secretions first react with magnetic microparticles (MMPs) and polystyrene microparticles (PMPs) that are surface-modified to form a "MMPs-anti-spike RBD IgG-PMPs" complex when RBD is present. After magnetic separation and loading into the microfluidic particle counter, the free PMPs, which are reduced with increasing anti-spike RBD IgG antibody levels, are trapped by a microfluidic particle dam and accumulate in the trapping channel. A sensitive mode [limit of detection (LOD): 14.0 ng mL-1; sample-to-answer time: 70 min] and an equipment-free rapid mode (LOD: 37.4 ng mL-1; sample-to-answer time: 20 min) were achieved. Eighty-seven nasal secretion (NS) samples from vaccinees were analyzed using our microfluidic particle counter, and the results closely resemble those of the gold-standard enzyme-linked immunosorbent assay (ELISA). The analysis shows that higher antibody levels were found in convalescent volunteers compared to noninfected volunteers. Together, we demonstrate a rapid kit that directly indicates immune status, which can guide vaccine strategy for individuals and the government.

Microglial exosomes in paraquat-induced Parkinson's disease: Neuroprotection and biomarker clues.

The exact mechanisms underlying the initiation and exacerbation of Parkinson's disease (PD) by paraquat remain unclear. We have revealed that exosomes mediate neurotoxicity induced by low dose paraquat exposure by transmitting intercellular signaling. Exposure to 40 µM paraquat promoted exosome release from mouse microglia cells (BV2) in vitro. Paraquat exposure at 100 µM caused degeneration of mouse dopaminergic MN9D cells and inhibited microglia exosome uptake by fluorescently labeling exosomes. We established an incubation model for exosomes and dopaminergic neuron cells under PQ treatment. The results indicated that microglial exosomes alleviated degeneration, increasing proliferation and PD-related protein expression of dopaminergic neurons; however, paraquat reversed this effect. Then, through exosome high-throughput sequencing and qRT-PCR experiments, miR-92a-3p and miR-24-3p were observed to transfer from exosomes to dopaminergic neurons, inhibited by paraquat. The specificity of miR-92a-3p and miR-24-3p was verified in PD patients exosomes, indicating the potential diagnostic value of the exosomal miRNAs in paraquat-induced PD. These results suggest glia-neuron communication in paraquat-induced neurodegeneration and may identify stable paraquat-mediated PD biomarkers, offering clues for early recognition and prevention of pesticide-induced degenerative diseases.

Three near-complete genome assemblies reveal substantial centromere dynamics from diploid to tetraploid in Brachypodium genus.

BACKGROUND: Centromeres are critical for maintaining genomic stability in eukaryotes, and their turnover shapes genome architectures and drives karyotype evolution. However, the co-evolution of centromeres from different species in allopolyploids over millions of years remains largely unknown. RESULTS: Here, we generate three near-complete genome assemblies, a tetraploid Brachypodium hybridum and its two diploid ancestors, Brachypodium distachyon and Brachypodium stacei. We detect high degrees of sequence, structural, and epigenetic variations of centromeres at base-pair resolution between closely related Brachypodium genomes, indicating the appearance and accumulation of species-specific centromere repeats from a common origin during evolution. We also find that centromere homogenization is accompanied by local satellite repeats bursting and retrotransposon purging, and the frequency of retrotransposon invasions drives the degree of interspecies centromere diversification. We further investigate the dynamics of centromeres during alloploidization process, and find that dramatic genetics and epigenetics architecture variations are associated with the turnover of centromeres between homologous chromosomal pairs from diploid to tetraploid. Additionally, our pangenomes analysis reveals the ongoing variations of satellite repeats and stable evolutionary homeostasis within centromeres among individuals of each Brachypodium genome with different polyploidy levels. CONCLUSIONS: Our results provide unprecedented information on the genomic, epigenomic, and functional diversity of highly repetitive DNA between closely related species and their allopolyploid genomes at both coarse and fine scale.

LncRNA NR_030777 promotes mitophagy by targeting CDK1-related mitochondrial fission and ATG12 to attenuate paraquat-induced Parkinson's disease.

With the evidence emerging that abnormal expression of long noncoding RNAs (lncRNAs) are involved in onset of Parkinson's disease (PD), the role of NR_030777 contributing to this disease is of great interest. We recently found that a novel lncRNA "NR_030777" demonstrates protective effects on PQ-induced neurodegeneration. However, the underlying molecular mechanisms of NR_030777 in the regulation of mitochondrial fission and mitophagy involved in PQ-induced neuronal damage remain to be explored. NR_030777 brain conditional overexpressing mice as well as in vitro primary neuronal cells from cerebral cortex and Neuro2a cells were adopted. Immunofluorescence, Immunohistochemistry, qRT-PCR and Western blotting were used to evaluate the expression levels of RNA and proteins. RNA immunoprecipitation and RNA pulldown experiment were used to evaluate the interaction of NR_030777 with its target proteins. NR_030777 and mitophagy were increased, and tyrosine hydroxylase (TH) levels recovered after NR_030777 overexpression upon PQ treatment. The overexpression and knockdown of NR_030777 unveiled that NR_030777 positively regulated mitophagy such as the upregulation of LC3B-II:I, ATG12-ATG5, p62 and NBR1. Moreover, the application of mdivi-1, a DRP-1 inhibitor, in combination with NR_030777 genetic modified cells unveiled that NR_030777 promoted DRP1-mediated mitochondrial fission and mitophagy. Furthermore, NR_030777 were directly bound to CDK1 to increase p-DRP1 levels at the Ser616 site, leading to mitochondrial fission and mitophagy. On the other hand, NR_030777 acted directly on ATG12 within the ATG12-ATG5 complex in the 800-1400 nt region to modulate the membrane formation. Accordingly, NR_030777 deficiency in neuron cells compromised cell mitophagy. Finally, the above findings were confirmed using NR_030777-overexpressing mice. NR_030777 exerted a protective effect on PQ-exposed mice by enhancing mitophagy. Our data provide the first scientific evidence for the precise invention of PQ-induced PD. Our findings further propose a breakthrough for understanding the regulatory relationship between NR_030777, CDK1, ATG12 and mitophagy in PQ-induced PD.

Single-cell RNA-sequencing of cellular heterogeneity and pathogenic mechanisms in paraquat-induced Parkinson's disease with depression.

Parkinson's disease (PD) is among the most prevalent neurodegenerative diseases, and approximately one third of patients with PD are estimated to have depression. Paraquat (PQ) exposure is an important environmental risk factor for PD. In this study, we established a mouse model of PQ-induced PD with depression to comprehensively investigate cellular heterogeneity and the mechanisms underlying the progression of depression in the context of PD. We utilized single-cell RNA-seq (scRNA-seq) to acquire the transcriptomic atlas of individual cells from model mice and characterize the gene expression profiles in each differentially expressed cell type. We identified a specific glutamatergic neuron cluster responsible for the development of heterogeneous depression-associated changes and established a comprehensive gene expression atlas. Furthermore, functional enrichment and cell trajectory analyses revealed that the mechanisms underlying the progression of PD with depression were associated with specific glutamatergic neurons. Together, our findings provide a valuable resource for deciphering the cellular heterogeneity of PD with depression. The suggested connection between intrinsic transcriptional states of neurons and the progression of depression can provide insight into potential biomarkers and specific targets for anti-depression treatment in patients with PD. SYNOPSIS: Our results obtained using model mice confirm the core effects of PQ exposure on glutamatergic neurons and their potential role in the development of PD with depression.