TCR-induced sumoylation of the kinase PKC-θ controls T cell synapse organization and T cell activation.

Sumoylation regulates many cellular processes, but its role in signaling via the T cell antigen receptor (TCR) remains unknown. We found that the kinase PKC-θ was sumoylated upon costimulation with antigen or via the TCR plus the coreceptor CD28, with Lys325 and Lys506 being the main sumoylation sites. We identified the SUMO E3 ligase PIASxß as a ligase for PKC-θ. Analysis of primary mouse and human T cells revealed that sumoylation of PKC-θ was essential for T cell activation. Desumoylation did not affect the catalytic activity of PKC-θ but inhibited the association of CD28 with PKC-θ and filamin A and impaired the assembly of a mature immunological synapse and central co-accumulation of PKC-θ and CD28. Our findings demonstrate that sumoylation controls TCR-proximal signaling and that sumoylation of PKC-θ is essential for the formation of a mature immunological synapse and T cell activation.

Diet therapy in patients with rare diseases: a scoping review.

BACKGROUND: This scoping review presents existing research evidence regarding diet therapy in patients with rare diseases (RDs). METHODS: Using the five-stage scoping review framework proposed by Arksey, O'Malley and Levac, we searched the published literature in PubMed, Web of Science, Royal Society of Chemistry, China National Knowledge Infrastructure, VIP Database and Wan Fang Database from January 2010 to November 2022. We selected diet therapy studies on 121 RDs, as categorised by the National Health Commission of China in 2018. Charts for research analysis were developed and used to categorise the data. RESULTS: We ultimately included 34 diet therapy studies from 19 countries and territories for 10 RDs and 3 RD groups. RD diet therapy studies have mainly focused on inborn errors of metabolism (92.3%) and are common in Western countries. Most studies focused on diet therapy methods for RDs (44%). In addition, 29% of studies included diet therapy management, 15% included guidelines for diet therapy and 12% included the impact of diet therapy on patients. CONCLUSIONS: Current diet therapies for RDs lack specificity and present with limited characteristics. Therefore, it is necessary to expand the scope and depth of future research and explore evidence-based recommendations and new diet therapies focused on patient needs and family support to provide a reference for improving the efficacy and safety of diet therapies for RDs.

Involvement of CXCL10 in Neuronal Damage under the Condition of Spinal Cord Injury and the Potential Therapeutic Effect of Nrg1.

OBJECTIVE: Few studies have reported the direct effect of C-X-C motif chemokine ligand 10 (CXCL10) and Neuregulin 1 (Nrg1) on neurons after spinal cord injury (SCI). This study reports the role of CXCL10 in the regulation of neuronal damage after SCI and the potential therapeutic effect of Nrg1. METHODS: The expression level of CXCL10 and Nrg1 in SCI mice was analyzed in the Gene Expression Omnibus DataSets, followed by immunohistochemical confirmation using a mouse SCI model. HT22 cells and NSC34 cells were treated with CXCL10 and Nrg1, individually or in combination, and then assayed for cell viability. The percentage of wound closure was determined through the cell scratch injury model using HT22 and NSC34 cells. Potential molecular mechanisms were also tested in response to either the individual administration of CXCL10 and Nrg1 or a mixture of both molecules. RESULTS: CXCL10 expression was significantly increased in both young and old mice subjected to SCI, while Nrg1 expression was significantly decreased. CXCL10 induced a decrease in cell viability, which was partially reversed by Nrg1. CXCL10 failed to inhibit scratch healing in HT22 and NSC34 cells, while Nrg1 promoted scratch healing. At the molecular level, CXCL10-activated cleaved caspase 9 and cleaved caspase 3 were both inhibited by Nrg1 through pERK1/2 signaling in HT22 and NSC34 cells. CONCLUSIONS: CXCL10 is upregulated in SCI. Despite the negative effect on cell viability, CXCL10 failed to inhibit the scratch healing of HT22 and NSC34 cells. Nrg1 may protect neurons by partially antagonizing the effect of CXCL10.

Association between gut microbial diversity and technique failure in peritoneal dialysis patients.

BACKGROUND: Gut dysbiosis in peritoneal dialysis (PD) patients causes chronic inflammation and metabolic disorders which result in a series of complications, probably playing an important role in PD technique failure. The reduction in gut microbial diversity was a common feature of gut dysbiosis. The objective was to explore the relationship between gut microbial diversity and technique failure in PD patients. METHODS: The gut microbiota was analyzed by 16s ribosomal RNA gene amplicon sequencing. Cox proportional hazards models were used to identify association between gut microbial diversity and technique failure in PD patients. RESULTS: In this study, a total of 101 PD patients were enrolled. During a median follow-up of 38 months, we found that lower diversity was independently associated with a higher risk of technique failure (hazard ratio [HR], 2.682; 95% confidence interval [CI], 1.319-5.456; p = 0.006). In addition, older age (HR, 1.034; 95% CI, 1.005-1.063; p = 0.020) and the history of diabetes (HR, 5.547; 95% CI, 2.218-13.876; p < 0.001) were also independent predictors for technique failure of PD patients. The prediction model constructed on the basis of three independent risk factors above performed well in predicting technique failure at 36 and 48 months (36 months: area under the curve [AUC] = 0.861; 95% CI, 0.836-0.886; 48 months: AUC = 0.815; 95% CI, 0.774-0.857). CONCLUSION: Gut microbial diversity was independently correlated with technique failure in PD patients, and some specific microbial taxa may serve as a potential therapeutic target for decreasing PD technique failure.

Using the theory of planned behaviour to explain junior nurses' and final-year student nurses' intention to care for COVID-19 patients in China: A multisite cross-sectional study.

AIM: To explore junior nurses' and final-year student nurses' intention to care for COVID-19 patients amidst the Delta COVID-19 variant outbreak in China using the theory of planned behaviour (TPB) as a framework. BACKGROUND: The COVID-19 pandemic has intensified global nursing shortage. Junior nurses and final-year student nurses represent the backbone of the future frontline nursing workforce. The TPB is a valid theoretical model for predicting nurses' caring behaviours. METHODS: A 47-item self-administered questionnaire was disseminated online to a convenience sample of 547 junior nurses and final-year student nurses located in 13 regions across mainland China. RESULTS: Approximately 63.4% of the participants intended to care for COVID-19 patients voluntarily and 65.6% by non-voluntary assignment. The TPB model significantly predicted 45% of the variance in behavioural intention, subjective norms being the strongest predictor. Gender, vaccination status and ethical perceptions regarding frontline work significantly correlated with the intention to provide care. CONCLUSIONS: Our findings highlight the importance of social, organisational and family support underpinning future junior nurses' professional commitment in times of public health crisis. IMPLICATIONS FOR NURSING MANAGEMENT: Pandemic-tailored workplace training programmes for nurses/student nurses that emphasize on self-care and ethical issue discussions are warranted. Hospital managers should collaborate with community partners to offer additional family support for nurses in need.

Risk perception, knowledge, information sources and emotional states among COVID-19 patients in Wuhan, China.

BACKGROUND: The rapidly evolving COVID-19 pandemic has become a global health crisis. Several factors influencing risk perception have been identified, including knowledge of the disease, information sources, and emotional states. Prior studies on COVID-19-related risk perception primarily focused on the general public, with little data available on COVID-19 patients. PURPOSE: To investigate COVID-19 patients' risk perception, knowledge of the disease, information sources, and emotional states in the epicenter, Wuhan, during the COVID-19 outbreak in China. METHODS: Data were collected online using self-administered electronic questionnaire developed with reference to previous relevant studies and publications by the World Health Organization. FINDINGS: A higher level of perceived risk was found in relation to COVID-19 as compared to other potential health threats. Knowledge gaps existed regarding transmission and prevention of COVID-19. Additionally, risk perception was negatively related to knowledge and positively related to depressive states. Moreover, social media was a primary source for COVID-19 information, whereas the most trusted sources were health professionals. DISCUSSION: Realistic perception of risk should be encouraged considering both physical and mental health while developing relevant strategies. Furthermore, risk communication needs to be specifically tailored for various target groups, such as the elderly and mentally vulnerable individuals, with the adoption of popular media platforms.

Plasmonic Colloidosome-Based Single Cell Detector: A Strategy for Individual Cell Secretion Sensing.

Phenotyping single cells based on molecules that they secrete or consume is a key bottleneck in many biotechnology applications. Here, we demonstrate a new approach for detecting secretions from individual single cells, namely, plasmonic colloidosome-based single cell detector (PCSD). This strategy uses colloidosomes to encapsulate single cells and aid molecular detection. Colloidosomes are constructed by emulsifying lactate probe and hydrophobic ligand dual-functionalized silver nanoparticles on an immiscible liquid-liquid interface. The established colloidosome-based platform exhibits negligible surface-enhanced Raman scattering (SERS) background interference, ultrasensitive SERS response, and excellent signal reproducibility in response to acidification of the medium inside the colloidosomes. Taking lactate as a model molecule, the acidification induced by single cells confined in the colloidosomes is detected. The approach shows promising applicability in single cell analysis based on extracellular metabolites production or consumption.

Single-Molecule Fluorescence Imaging for Ultrasensitive DNA Methyltransferase Activity Measurement and Inhibitor Screening.

Aberrant DNA methylation by DNA methyltransferases (MTase) is related to the initiation and progression of many diseases. Thus, site-specific identification of DNA methylation and detection of MTase activity are very important to diagnose and treat methylation-related diseases. Herein, a single-molecule counting based ultrasensitive assay was developed for facile and direct detection of MTase activity and inhibitor screening without the assistance of restriction endonuclease. A double-strand DNA (dsDNA) was designed with the recognition site of M. SssI MTase and assembled on the coverslip surface. After the dsDNA was methylated by M. SssI, the biotin conjugated anti-5-methylcytosine antibody (5mC Ab) would specifically bind the CpG methylation site, and subsequently, the streptavidin-labeled quantum dots (QS585) bind the biotins. By taking and counting the image spots of fluorescently labeled methylated dsDNA molecules, the single-molecule imaging of methylated dsDNA molecules was recorded to quantify the DNA MTase activity. The spot number shows a linear relation with the logarithm of M. SssI concentration in the concentration range of 0.001-1 U/mL. Compared with most of the state of the art methods, the proposed assay displays a lower detection limit of 0.0005 U/mL and can detect the DNA MTase more directly. Moreover, it can selectively detect M. SssI in more complex samples. In addition, it is further demonstrated that the protocol could be successfully applied to evaluate the inhibition efficiency of M. SssI inhibitors. This assay is anticipated to provide a new approach for clinical diagnosis of methylation-related diseases and screening of new anticancer drugs.

Gas chromatography-mass spectrometry based metabolomics profile of hippocampus and cerebellum in mice after chronic arsenic exposure.

Intake of arsenic (As) via drinking water has been a serious threat to global public health. Though there are numerous reports of As neurotoxicity, its pathogenesis mechanisms remain vague especially its chronic effects on metabolic network. Hippocampus is a renowned area in relation to learning and memory, whilst recently, cerebellum is argued to be involved with process of cognition. Therefore, the study aimed to explore metabolomics alternations in these two areas after chronic As exposure, with the purpose of further illustrating details of As neurotoxicity. Twelve 3-week-old male C57BL/6J mice were divided into two groups, receiving deionized drinking water (control group) or 50 mg/L of sodium arsenite (via drinking water) for 24 weeks. Learning and memory abilities were tested by Morris water maze (MWM) test. Pathological and morphological changes of hippocampus and cerebellum were captured via transmission electron microscopy (TEM). Metabolic alterations were analyzed by gas chromatography-mass spectrometry (GC-MS). MWM test confirmed impairments of learning and memory abilities of mice after chronic As exposure. Metabolomics identifications indicated that tyrosine increased and aspartic acid (Asp) decreased simultaneously in both hippocampus and cerebellum. Intermediates (succinic acid) and indirect involved components of tricarboxylic acid cycle (proline, cysteine, and alanine) were found declined in cerebellum, indicating disordered energy metabolism. Our findings suggest that these metabolite alterations are related to As-induced disorders of amino acids and energy metabolism, which might therefore, play an important part in mechanisms of As neurotoxicity.

Three-Dimensional Plasmonic Trap Array for Ultrasensitive Surface-Enhanced Raman Scattering Analysis of Single Cells.

Single-cell analysis provides an important strategy to evaluate cellular heterogeneity. Although surface-enhanced Raman scattering (SERS) has been considered as a promising label-free technique for single-cell analysis, it remains at the early stage for characterizing the extracellular metabolites of single cells. Herein, we developed a convenient, flexible, and straightforward three-dimensional (3D) plasmonic trap array for simultaneously compartmentalizing and sensitively detecting single-cell metabolites. The 3D trap was spontaneously self-formed by an interfacial-energy-driven process when a liquid droplet was covered with an immiscible oil liquid (polydimethylsiloxane, PDMS). When a droplet of pure AgNO3 solution was immersed into PDMS, Ag+ ions were automatically reduced by the residual Si-H groups in PDMS. Snowflake-like nanoparticles of Ag could be formed on the inner surface of the 3D traps by tuning the concentration of Ag salt precursors and then assembled to flower-like microstructures, endowing the traps with remarkable plasmon enhancement. The established 3D traps exhibited considerably enhanced surface plasmon resonance signals for Raman reporting, and a low detection limit at the aM level was achieved for p-aminothiophenol. Moreover, these 3D traps can serve as an efficient tool for single-cell SERS measurement. As a proof-of-concept, dipicolinic acid, a common biomarker of bacterial spores, was successfully detected from a single cell. The presented approach provides a versatile tool for label-free and sensitive detection of single-cell environments.

Single Molecule Fluorescent Colocalization of Split Aptamers for Ultrasensitive Detection of Biomolecules.

Single-molecule fluorescence imaging is a promising strategy for biomolecule detection. However, the accuracy of single-molecule method is often compromised by the false-positive events at the ultralow sample levels that are caused by the nonspecific adsorption of the fluorescent labeled probe and other fluorescent impurities on the imaging surface. Here, we demonstrate an ultrasensitive single molecule detection assay based on dual-color fluorescent colocalization of spilt aptamers that was implemented to the measurement of adenosine triphosphate (ATP). The ATP aptamer was split into two fragments and labeled with green and red dye molecules, respectively. When the two probes of split aptamers were brought together by the target ATP molecule, the two colors of fluorescence of two probes were simultaneously detected through two channels and projected to the correlated locations in the two halves of image. The colocalizaiton imaging of two split apatamer probes greatly excluded the false detection of biomolecules that was usually caused by the fluorescent noise of single nonbound aptamer probes and impurities, and further improved the accuracy of measurement. The assay showed excellent selectivity and high sensitivity for ATP detection with linear range of 1 pM to 5 nM and a detection limit of 100 fM. This versatile protocol of single molecule colocalization of split apatamer can be widely applied to the ultrasensitive and highly accurate detection of many types of biomolecules in basic research and biomedical applications.

Mesoporous Silica for Triphase Nucleophilic Substitution Reactions.

Mesoporous silica SBA-15 is shown to be a very efficient alternative to phase transfer catalyst salts for two-phase nucleophilic substitutions. The two-phase reaction can efficiently take place in the absence of PTCs. The high catalytic activity and reaction rates can be attributed to the amphiphilic and negatively charged surface of SBA-15 as well as the rapid ingress of the reactants and egress of the products.

Cellular models for mitochondrial DNA-based diseases: lymphoblastoid cell lines and transmitochondrial cybrids.

Mitochondrial DNA (mtDNA) mutations cause a variety of mitochondrial DNA-based diseases which have been studied using Lymphoblastoid cell lines (LCLs) and transmitochondrial cybrids. Individual genetic information is preserved permanently in LCLs while the development of transmitochondrial cybrids provide ex-vivo cellular platform to study molecular mechanism of mitochondrial DNA-based diseases. The cytoplasmic donor cells for previous transmitochondrial cybrids come from patient's tissue or platelet directly. Here, we depicted in details the principle, methods and techniques to establish LCLs from frozen peripheral bloods harboring mitochondrial 4401G > A mutation by infection of Epstein Barr virus, and then to generate cybrids using ρ0 206 and LCLs. The process of establishing these two cellular models was summarized into four steps as follows: (1) Generation of LCLs; (2) Transformation; (3) Selection; (4) Verification. To faithfully represent the function of mtDNA mutation, we analyzed and identified the sites of mtDNA mutations and copy numbers of each cellular models as well as the karyotype of transmitochondrial cybrids. Those clones with consistent parameters were selected for preservation and future analysis of the function of point mutations of mtDNA. Although these two cellular models play important roles in understanding molecular mechanism of mitochondrial DNA-based diseases on the cellular level, their limitations should be considered when elucidating the character of tissue specificity of mitochondrial DNA-based diseases.

Quantitative label-free and real-time surface-enhanced Raman scattering monitoring of reaction kinetics using self-assembled bifunctional nanoparticle arrays.

Although surface-enhanced Raman scattering (SERS) has proven to be an effective tool for label-free monitoring of catalytic reactions, quantitative characterization of reaction kinetics via this technique remains challenging owing to the difficulty in integrating catalytic and plasmonic activities into a single platform. In this work, we report on an easy access to highly sensitive plasmonic nanoarrays for direct and label-free monitoring of a gold-catalyzed reaction by SERS. The hierarchically structured three-dimensional assemblies, which consist of small gold catalyst nanoparticles distributed on a self-assembled monolayer of larger gold nanoparticles, were formed through a simple and rapid stepwise interfacial self-assembling process (fabrication time <10 min). The well-defined interparticle distances (<1 nm) lead to efficient plasmonic coupling and ensure both catalytic and SERS-active sites exposed to the environment. Such a versatile bifunctional platform thus allows quantitative determination of the rate constant and activation energy of the catalytic reaction with SERS.

Carbon nanotube/gold nanoparticle composite-coated membrane as a facile plasmon-enhanced interface for sensitive SERS sensing.

The facile assembly of three-dimensional (3D) plasmonic substrates has been demonstrated. The assembly is based on the homogeneous decoration of multi-walled carbon nanotube/gold nanoparticle (CNT/AuNP) hybrid nanocomposites on a commercial polyvinylidene difluoride (PVDF) membrane, which is achieved via simple filtration. The CNT/AuNP hybrids with a unique 1D/0D structure remarkably improve the coverage and uniformity of plasmonic nanostructures on the membrane. The effective inter-particle and inter-tube coupling creates a multitude of hot spots within the probe area, and can produce a strong SERS effect. Moreover, the flexible membrane-based scaffold can efficiently collect and concentrate trace targets from large-volume sample solutions at milliliter-scale. The membrane-based SERS sensor shows high sensitivity and good reproducibility. The SERS sensor is employed to detect various molecular contaminants in aqueous samples, demonstrating its excellent field-testing capabilities for applications ranging from food safety to environmental monitoring.

TNFR-associated factor 6 regulates TCR signaling via interaction with and modification of LAT adapter.

TNFR-associated factor (TRAF)6 is an essential ubiquitin E3 ligase in immune responses, but its function in adaptive immunity is not well understood. In this study, we show that TRAF6 is recruited to the peripheral ring of the T cell immunological synapse in Jurkat T cells or human primary CD4(+) T cells conjugated with staphylococcal enterotoxin E-pulsed B cells. This recruitment depends on TRAF6 interacting with linker for activation of T cells (LAT) via its TRAF domain. Although LAT was indispensable for TCR/CD28-induced TRAF6 ubiquitination and its ligase activity, RNA interference-induced TRAF6 knockdown in T cells decreased TCR/CD28-induced LAT ubiquitination, tyrosine phosphorylation, and association with tyrosine kinase ZAP70. Overexpression of TRAF6 or its catalytically inactive form C70A promoted and decreased, respectively, LAT tyrosine phosphorylation upon stimulation. Moreover, LAT was ubiquitinated at Lys(88) by TRAF6 via K63-linked chain. In addition, TRAF6 was required for and synergized with LAT to promote the TCR/CD28-induced activation of NFAT. These results reveal a novel function and mechanism of TRAF6 action in the TCR-LAT signaling pathway distinct from its role in TCR-induced NF-κB activation, indicating that LAT also plays an adapter role in TCR/CD28-induced activation of TRAF6.

Interfacial self-assembled functional nanoparticle array: a facile surface-enhanced Raman scattering sensor for specific detection of trace analytes.

Surface-enhanced Raman scattering (SERS) has proven to be promising for the detection of trace analytes; however, the precise nanofabrication of a specific and sensitive plasmonic SERS-active substrate is still a major challenge that limits the scope of its applications. In this work, gold nanoparticles are self-assembled into densely packed two-dimensional arrays at a liquid/liquid interface between dimethyl carbonate and water in the absence of template controller molecules. Both the simulation and experiment results show that the particles within these film-like arrays exhibit strong electromagnetic coupling and enable large amplification of Raman signals. In order to realize the level of sensing specificity, the surface chemistry of gold nanoparticles (Au NPs) is rationally tailored by incorporating an appropriate chemical moiety that specifically captures molecules of interest. The ease of fabrication and good uniformity make this platform ideal for in situ SERS sensing of trace targets in complex samples.

Mechanisms of the InCl3-catalyzed type-I, II, and III cycloisomerizations of 1,6-enynes.

InCl3-catalyzed cycloisomerizations of 1,6-enynes can give either type-I dienes and cyclohexenes (type-III dienes), or type-II dienes, depending on the substitutions in the substrates. Previously, we studied how the type-II diene products were generated and found that the real catalytic species for the cycloisomerizations is InCl2(+) (J. Org. Chem. 2012, 77, 8527-8540). In the present paper, we used density functional theory (DFT) calculations to reveal how the type-I and type-III dienes were generated. A unified model to explain how substituents affect the regiochemistry of type-I, II, and III cycloisomerizations has been provided. Experimental and computational investigation of the InCl3-catalyzed cycloisomerization of 1,6-enynes with both substituents at the alkyne and alkene parts has also been reported in the present study.

Low expression of basic fibroblastic growth factor in mesenchymal stem cells and bone marrow of children with aplastic anemia.

BACKGROUND: Our previous experiments with gene chip suggested that basic fibroblastic growth factor (FGF2) levels were lower in mesenchymal stem cell (MSC) from aplastic anemia patients. The purpose of this study was to determine the expression of FGF2 in MSC and in bone marrow of children with aplastic anemia to better understand the role of low FGF2 expression in the pathogenesis of aplastic anemia. PROCEDURE: MSCs from the bone marrow of aplastic anemia children and control group were cultured in vitro. Growth curves of primary and passage MSC were plotted. FGF2 gene expression in MSCs was detected using quantitative real-time polymerase chain reaction (RT-PCR). FGF2 protein expression in mononuclear cells and FGF2 protein level in extracellular fluid of bone marrow were also investigated. RESULT: Decreased growth of MSCs from aplastic anemia children was observed after passage 8 in serial subcultivation, and FGF2 gene expression was downregulated. Within the patients' bone marrow, low FGF2 expression was validated both in mononuclear cells and in the extracellular fluid. CONCLUSION: Low FGF2 gene expression in MSCs and low FGF2 protein level in bone marrow of aplastic anemia may involve to pathogenesis of aplastic anemia.

Home care needs assessment among caregivers of children and adolescents with osteogenesis imperfecta: a cross-sectional study.

BACKGROUND: Children and adolescents with complex medical issues need home care services; however, few studies have provided insight into the unmet home care needs of the families of patients with osteogenesis imperfecta (OI). In this study, we aimed to assess the home care needs of caregivers of children and adolescents with OI and the associated factors. METHODS: A self-administered questionnaire was administered online to 142 caregivers of patients with OI aged 3-17 years between May and October 2022 from 25 provinces in China. The questionnaire comprised 15 questions on demographic variables and 14 questions on home care needs. Chi-square analysis was used to compare group differences for categorical variables. Multivariate binary logistic regression analysis was conducted to examine predictors of caregivers' home care needs. RESULTS: The study findings indicated that 81.5% of caregivers had high home care needs. The three leading types of home care needs were helping the child carry out physical fitness recovery exercises at home (72.5%), understanding precautions regarding treatment drugs (72.5%), and relieving the child's pain (70.4%). OI patients' poor self-care ability (adjusted odds ratio = 5.9, 95% confidence interval = 1.8-19.0) was related to caregivers' high level of home care needs. CONCLUSIONS: The findings of this study suggest that future scientific research and nursing guidance should focus on OI patients' physical training, medication management, pain relief, fracture prevention, and treatment. In addition, caregivers of patients with poor self-care ability should receive special attention in the development of interventions. This study can help with addressing the unmet home care needs of caregivers of children and adolescents with OI. It is vital to develop a personalized intervention plan based on patients' self-care ability.