ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

OBJECTIVE: To analyze the significance of total vitamin D (tVD), total procollagen type I amino-terminal propeptide (tPINP) and β-CrossLaps (β-CTx) in the staging and prognosis of patients with multiple myeloma (MM). METHODS: A total of 54 patients with newly diagnosed MM admitted to the Second Affiliated Hospital of Fujian Medical University from 2020 to 2022 were selected as the observation group (MM group), and 50 healthy persons who underwent physical examinations in our hospital were selected as the control group. The expression levels of tVD, tPINP and β-CTx in the two groups were detected by chemiluminescence method. The differences in the expression levels of tVD, tPINP and β-CTx among MM patients at different ISS stages were analyzed. The expression levels of tVD, tPINP and β-CTx in MM patients with different levels of hemoglobin (Hb), serum calcium (Ca), creatinine (Crea), albumin (ALB), β₂-microglobulin (β₂-MG) and lactate dehydrogenase (LDH) were compared. The correlations between the expression levels of tVD, tPINP, β-CTx and the aforementioned clinical parameters were analyzed, respectively. The relationship between the expression levels of tVD, tPINP, β-CTx and the progression-free survival (PFS) of MM patients was analyzed. RESULTS: The expression level of tVD in the MM group was significantly lower than that in the control group (21.73±14.45 ng/ml vs 30.78±9.94 ng/ml, P =0.022). The expression level of β-CTx in the MM group was significantly higher than that in the control group (1.43±0.99 ng/ml vs 0.53±0.29 ng/ml, P =0.013). The tVD level in MM patients with ISS stage I-II was significantly higher than that of MM patients with ISS stage III (29.50±14.59 ng/ml vs 12.62±7.73 ng/ml, P =0.028), indicating that the higher the ISS stage, the lower the tVD level. The tPINP and β-CTx levels in MM patients with high Ca levels (>2.65 mmol/L) were significantly higher than those in patients with low Ca levels (≤2.65 mmol/L) (P =0.016, P =0.021). The tVD level of MM patients was positively correlated with the ALB level (r =0.570), tPINP was positively correlated with Ca and β₂-MG levels (r =0.791,r =0.673), and β-CTx was positively correlated with tPINP level (r =0.616). The PFS of the low tVD expression group was significantly lower than that of the high tVD expression group (P =0.041). CONCLUSION The expression level of tVD is decreased in MM patients, which can be used as an indicator to evaluate the disease stage and prognosis of the patients. The β-CTx expression level is increased in MM patients. tPINP and β-CTx may be correlated with clinical symptoms such as osteolytic lesions and renal function changes in MM patients.
Humans ; Multiple Myeloma/pathology* ; Procollagen/blood* ; Vitamin D/blood* ; Prognosis ; Peptide Fragments/blood* ; Collagen Type I/blood* ; Female ; Male ; Middle Aged ; Aged ; Neoplasm Staging

Early-life stress (ES) leads to cognitive dysfunction in female adolescents, but the underlying neural mechanisms remain elusive. Recent evidence suggests that the cell adhesion molecules NECTIN1 and NECTIN3 play a role in cognition and ES-related cognitive deficits in male rodents. In this study, we aimed to investigate whether and how nectins contribute to ES-induced cognitive dysfunction in female adolescents. Applying the well-established limited bedding and nesting material paradigm, we found that ES impairs recognition memory, suppresses prefrontal NECTIN1 and hippocampal NECTIN3 expression, and upregulates corticotropin-releasing hormone (Crh) and its receptor 1 (Crhr1) mRNA levels in the hippocampus of adolescent female mice. Genetic experiments revealed that the reduction of dorsal CA1 (dCA1) NECTIN3 mediates ES-induced object recognition memory deficits, as knocking down dCA1 NECTIN3 impaired animals' performance in the novel object recognition task, while overexpression of dCA1 NECTIN3 successfully reversed the ES-induced deficits. Notably, prefrontal NECTIN1 knockdown did not result in significant cognitive impairments. Furthermore, acute systemic administration of antalarmin, a CRHR1 antagonist, upregulated hippocampal NECTIN3 levels and rescued object and spatial memory deficits in stressed mice. Our findings underscore the critical role of dCA1 NECTIN3 in mediating ES-induced object recognition memory deficits in adolescent female mice, highlighting it as a potential therapeutic target for stress-related psychiatric disorders in women.
Animals ; Female ; Mice ; CA1 Region, Hippocampal/metabolism* ; Cell Adhesion Molecules/metabolism* ; CRF Receptor, Type 1/metabolism* ; Memory Disorders/etiology* ; Mice, Inbred C57BL ; Nectins/genetics* ; Receptors, Corticotropin-Releasing Hormone/antagonists & inhibitors* ; Recognition, Psychology/physiology* ; Stress, Psychological/complications*

OBJECTIVE: To develop and validate a nomogram model for predicting 30-day mortality among elderly patients with sepsis-associated liver dysfunction (SALD), to identify high-risk patients and improve prognosis. METHODS: A retrospective cohort study was conducted using data extracted from the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database for elderly patients with SALD who were first admitted to the intensive care unit (ICU) of Beth Israel Deaconess Medical Center between 2008 and 2019, including basic characteristics, severity scores, underlying diseases, infection foci, 24-hour vital signs, initial laboratory indicators, 24-hour complications, and prognosis related indicators. Patients were randomly assigned to training group and validation group in a ratio of 7 : 3. The training group used the LASSO regression analysis, as well as multivariate Logistic regression analysis to screen for independent risk factors for 30-day mortality. A nomogram prediction model was constructed, and receiver operator characteristic curve (ROC curve), calibration curves, and decision curve analysis (DCA) were used to evaluate the model, and validate the model using the validation cohort. RESULTS: A total of 630 elderly patients with SLAD were included in the study, including 441 in the training group and 189 in the validation group. Oxford acute severity of illness score (OASIS) for training group [odds ratio (OR) = 1.060, 95% confidence interval (95%CI) was 1.034-1.086], 24-hour pulse oxygen saturation (SpO₂; OR = 0.876, 95%CI was 0.797-0.962), initial mean corpuscular volume (MCV; OR = 1.043, 95%CI was 1.009-1.077), initial red blood cell distribution width (RDW; OR = 1.237, 95%CI was 1.123-1.362), initial blood glucose (OR = 1.008, 95%CI was 1.004-1.013), and initial aspartate aminotransferase (AST; OR = 1.000, 95%CI was 1.000-1.001) were independent risk factors for 30-day mortality in patients (all P < 0.05). Based on the above variables, a nomogram model was constructed, and the ROC curve showed that the area under the curve (AUC) of the model in the training group was 0.757 (95%CI was 0.712-0.803), with a sensitivity of 65.05% and a specificity of 74.90%; the AUC of the model in the validation group was 0.712 (95%CI was 0.631-0.792), with a sensitivity of 58.67% and a specificity of 81.58%. The calibration curves of the training and validation groups show that both the fitted curves were close to the standard curves. The Hosmer-Lemeshow test: the training group (χ ² = 6.729, P = 0.566), the validation group (χ ² = 13.889, P = 0.085), indicating that the model can fit the observed data well. The DCA curve shows that when the threshold probability of the training group was 16% to 94% and the threshold probability of the validation group was 27% to 99%, the net benefit of the model was good. CONCLUSIONS OASIS, 24-hour SpO₂, initial MCV, initial RDW, initial blood glucose and initial AST are independent risk factors for 30-day mortality in elderly patients with SALD. The nomogram based on these six variables demonstrates good predictive performance.
Humans ; Sepsis/complications* ; Retrospective Studies ; Nomograms ; Aged ; Prognosis ; Risk Factors ; Liver Diseases/mortality* ; Intensive Care Units ; ROC Curve ; Male ; Female ; Logistic Models

Objective: Bariatric surgery effectively treats non-alcoholic fatty liver disease (NAFLD). The glutamate-serine-glycine (GSG) index has emerged as a non-invasive diagnostic marker for NAFLD, but its ability to monitor treatment response remains unclear. This study investigates the GSG index's ability to monitor NAFLD's response to bariatric surgery. Methodology: Ten NAFLD participants were studied at baseline and 6 months post-bariatric surgery. Blood samples were collected for serum biomarkers and metabolomic profiling. Hepatic steatosis [proton density fat fraction (PDFF)] and fibroinflammation (cT1) were quantified with multiparametric magnetic resonance imaging (mpMRI), and hepatic stiffness with magnetic resonance elastography (MRE). Amino acids and acylcarnitines were measured with mass spectrometry. Statistical analyses included paired Student’s t-test, Wilcoxon-signed rank test, and Pearson’s correlation. Results: Eight participants provided complete data. At baseline, all had hepatic steatosis (BMI 39.3 ± 5.6 kg/m2, PDFF ≥ 5%). Post-surgery reductions in PDFF (from 12.4 ± 6.7% to 6.2 ± 2.8%, p = 0.013) and cT1 (from 823.3 ± 85.4ms to 757.5 ± 41.6ms, p = 0.039) were significant, along with the GSG index (from 0.272 ± 0.03 to 0.157 ± 0.05, p = 0.001). Conclusion The GSG index can potentially be developed as a marker for monitoring the response of patients with NAFLD to bariatric surgery.
Non-alcoholic Fatty Liver Disease ; Amino Acids ; Metabolomics

Nicotinic acetylcholine receptors (nAChRs) belong to ligand-gated ion channel receptors, of which α7 nAChR subtype is widely distributed in the cerebral cortex, thalamus, hippocampus, and also identified in microglia, macrophages, bone marrow cells, etc. Previous studies revealed that α7 nAChR is closely related to the function of the cholinergic anti-inflammatory pathway, and is a vital target for drug development of Alzheimer's disease and schizophrenia. The establishment of a stable α7 nAChR in vitro drug screening system is crucial for the efficient screening of novel drugs targeting this target. Recombinant expression of different subtypes of nAChRs on Xenopus laevis oocyte membranes and current detected by two-electrode voltage clamp (TEVC) is an advanced and complex model for novel drug screening. Molecular chaperones can assist the assembly of some nAChR subunits to form functional receptors, providing a stable expression model for the screening of compounds targeting this receptor. In this study, a molecular chaperone gene of α7 nAChR, transmembrane protein 35A (Tmem35a), was isolated and cloned from rats. We constructed the recombinant expression vector and obtained the cRNA of Tmem35a by in vitro transcription technique. Two cRNAs (Tmem35a and α7) were mixed and injected into X. laevis oocytes for expression. Then, the effects of this molecular chaperone on the current expression and pharmacological properties of α7 nAChR were evaluated by the TEVC. The results revealed that TMEM35A, also known as novel acetylcholine receptor chaperone (NACHO) could effectively increase the expression of α7 nAChR protein on oocyte membranes, and the amount of α7 nAChR protein was increased about 1-fold. The peak current induced by agonist acetylcholine (ACh) was increased about 10-fold. After injection of Tmem35a cRNA, the median effect concentration (EC₅₀) value of α7 nAChR to agonist ACh is 228.5 μmol·L^-1, which shows almost no difference from native α7 nAChR (EC₅₀: 223.3 μmol·L^-1), indicating the preservation of the normal properties of α7 nAChR. The results of this investigation indicate that the molecular chaperone NACHO effectively assists the heterologous expression of α7 nAChR in X. laevis oocytes, which provides a model for screening the potency of lead compounds targeting α7 nAChR. All animal experiments in this study were reviewed and approved by the Ethics Committee of Guangxi University (approval number: GXU-2023-0249).

N-type voltage-gated calcium (Ca²⁺) channels (N-type VGCC, Ca_V2.2) mediate Ca²⁺ influx in response to action potential at the presynaptic terminal, and play an important role in synaptogenesis, neurotransmitter release and nociceptive signal transduction. It is a new target for the development of drugs for the treatment of neuralgia (chronic pain) and other major diseases. Due to the difficulty of calcium channel expression in vitro and the detection of channel current, there is a great lack of new drug screening models. In this study, we established and optimized the electrophysiological drug screening model using Xenopus laevis oocytes for the recombinant expression of Ca_V2.2 in vitro (this study were reviewed and approved by the Ethics Committee of Guangxi University, approval number: GXU-2023-0249). Firstly, the linear plasmids encoding cDNA of major subunit α1B and auxiliary subunits α2δ1 and β3 of rat Ca_V2.2 were used as templates for in vitro transcription to generate their related mRNA (cRNA), after which three kinds of cRNA were injected into Xenopus laevis oocytes at the mass ratio of 2∶1∶1 for expression. The two-electrode voltage clamp (TEVC) technique was used to detect the inward current produced by Ca_V2.2. At the same time, the expression conditions of Ca_V2.2 were optimized, and its gating function was characterized from the aspects of channel activation and inactivation. The results showed that 3-5 days after cRNA microinjection, stable Ca_V2.2-mediated barium ion (Ba²⁺) currents were successfully detected. The interference of endogenous potassium channels and Ca²⁺-activated chloride channels can be eliminated by tetraethylammonium hydroxide (TEAOH) and 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis (BAPTA-AM) treatment. The maximum potential for Ca_V2.2 activation is 0 mV, and the current reverses to be outward when the membrane potential is greater than +50 mV. By fitting the steady-state activation and inactivation curves, the half-maximal activation potential and half-maximal inactivation potential of Ca_V2.2 are identified as -15.9 and -60.2 mV. In this study, a stable Ca_V2.2 expression system was established based on Xenopus laevis oocytes. The in vitro expression system can provide a new way for the screening of Ca_V2.2 active compounds or lead drugs.

Objective:To investigate the effect of sleep on physical performance and the correlation between sleep quality and physical performance in the elderly.Methods:In this prospective multicenter case-control study, 472 elderly people aged 60-80 years were recruited from three regions in China, Beijing, Tianjin, and Hainan Province.Basic information of study participants was collected through face-to-face interviews, and physical performance of study participants was assessed by the time up and go(TUG)test on site, with 106 cases(22.5%)in the normal physical performance group and 366 cases(77.5%)in the abnormal group.The Pittsburgh Sleep Quality Index(PSQI)and the Epworth Sleepiness Scale(ESS)were applied to assess sleep quality of study subjects.Correlation analysis was performed to examine factors affecting subjects' physical performance.Results:Age, history of alcohol consumption, BMI, past medical history, the ESS score, daytime sleepiness, and some components of PSQI, such as sleep quality, sleep efficiency, sleep disturbances, use of sleeping drugs and daytime dysfunction, were influencing factors of the TUG score.Two components of PSQI, sleep duration and habitual sleep efficiency, and the ESS score were positively correlated with physical performance.Logistic regression analysis showed that risk factors for decreased physical performance in the elderly included increased age( OR=1.125, 95% CI: 1.083-1.168, P<0.01), history of alcohol consumption( OR=0.482, 95% CI: 0.384-0.605, P<0.001), abnormally high body mass index( OR=1.663, 95% CI: 1.340-2.063, P<0.01), hyperlipemia( OR=0.156, 95% CI: 0.077-0.318, P<0.01), digestive system diseases( OR=0.154, 95% CI: 0.044-0.532, P<0.01), use of sleeping drugs( OR=0.415, 95% CI: 0.202-0.854, P<0.05), daytime sleepiness( OR=4.234, 95% CI: 2.800-6.403, P<0.01), a high habitual sleep efficiency score of PSQI( OR=1.425, 95% CI: 1.214-1.672, P<0.01)and a high sleep disturbances score in PSQI( OR=3.356, 95% CI: 2.337-4.819, P<0.01). Conclusions:The incidence of physical performance decline is high in the elderly.There is a correlation between physical performance and sleep quality.