BACKGROUND: Regulatory dendritic cell (DCreg) subset exhibits a unique capacity for inducing immune tolerance among the variety subsets of dendritic cells (DCs) within gut-associated lymphoid tissues (GALTs). Fms-like tyrosine kinase 3 ligand (FLT3L) is involved in the differentiation of DCregs and the subsequent expansion of regulatory T-cells (Tregs) mediated by DCregs, though the precise mechanism remains poorly understood. This study aimed to explore the expansion mechanism of Treg induced by DCreg and the role of FLT3L in this process. METHODS: DCregs were distinguished from other DC subsets isolated from GALTs of BALB/c mice through a mixed lymphocyte reaction assay. The functions and mechanisms by which FLT3L promoted Treg expansion via DCregs were investigated in vitro through co-culture experiments involving DCregs and either CD4 + CD25 - T-cells or CD4 + CD25 + T-cells. Additionally, an in vivo experiment was conducted using a dextran sulfate sodium (DSS)-induced colitis model in mice. RESULTS: CD103 + CD11b + DC exhibited DCreg-like functionality and was identified as DCreg for subsequent investigation. Analysis of Foxp3 + Treg percentages within a co-culture system of CD4 + CD25 - T-cells and DCregs, with or without FLT3L, demonstrated the involvement of the FLT3/FLT3L axis in driving the differentiation of precursor T-cells into Foxp3 + Tregs induced by DCregs. Cell migration and co-culture assays revealed that the FLT3/FLT3L axis enhanced DCreg migration toward Tregs via the Rho pathway. Additionally, it was observed that DCregs could promote Treg proliferation through the Notch pathway, as inhibition of Notch signaling by DAPT (N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester) suppressed Treg expansion within the co-culture system of DCregs and CD4 + T-cells or CD4 + CD25 + T-cells. Furthermore, the FLT3/FLT3L axis influenced JAG1 expression in DCregs, indirectly modulating Treg expansion. In vivo experiments further established that FLT3L promoted DCreg expansion and restored Treg balance in DSS-induced colitis models, thereby ameliorating colitis symptoms in mice. CONCLUSION The FLT3/FLT3L axis is integral to the maintenance of DCreg function in Treg expansion.
Animals ; T-Lymphocytes, Regulatory/immunology* ; Dendritic Cells/immunology* ; Mice ; Mice, Inbred BALB C ; Membrane Proteins/metabolism* ; Receptors, Notch/metabolism* ; Lymphoid Tissue/metabolism* ; Signal Transduction/physiology* ; Coculture Techniques ; Flow Cytometry

[This corrects the article DOI: 10.1016/j.apsb.2022.03.002.].

Most patients with stroke experience obstructive sleep apnea (OSA), which has a negative impact on functional outcome and cognitive function in patients with stroke and is associated with increased mortality. Continuous positive airway pressure (CPAP) is a gold standard for treating OSA. This article reviews the effect of CPAP on functional outcome and cognitive function in stroke patients with OSA.

Objective To calculate the leakage rate of the automated watering system in Tsinghua University Laboratory Animal Resources Center, to evaluate the safety of the system, and provide references for selection, maintenance, and management of automated watering systems in animal facilities.MethodsThis study investigated the automated watering system installed in South and North Barriers of Tsinghua University Laboratory Animal Resources Center (Phase II). Water leakage monitoring was conducted over two periods, one over a period of 3 years and the other over 1.5 years. The occurrence of water leakage events at the two barriers during the monitoring period was statistically analyzed, classifying the causes into four categories: mishandling by personnel, animal behavior, obstruction by foreign objects, and deformation of fittings. The total daily leakage rate due to these causes and the daily leakage rate caused by quality issues, i.e. obstruction by foreign objects and deformation of fittings were calculated. Further analysis and discussion focused on the causes of water leakage and its impact on the facilities. At the same time, the number of caretakers at the end of the monitoring period in the Phase I facility without automated watering system and the Phase II facility with automated watering system were counted. Finally the difference in the number of cages per capita under the two watering systems was calculated.ResultsA total of 52 water leakage incidents occurred in both areas during the monitoring period, with a total daily leakage rate of 0.000 13%. Among them, 31 were caused by personnel mishandling, accounting for approximately 60% of total leakages. Enhanced training, supervision, inspection, and effective reminder measures could reduce leakage caused by personnel mishandling. There were 2 cases of water leakages caused by animal behavior, 0 leakage due to obstruction by foreign objects, and 19 leakages due to system quality issues, with a daily leakage rate of 0.000 07%. According to the operation data of Tsinghua University Laboratory Animal Resources Center, the average number of cages managed per person in facilities equipped with the automated watering system was 908, compared to 570 cages in facilities without the automated watering system. This represents an approximate 59% increase in the number of cages managed per person with the adoption of the automated watering system.Conclusion The daily leakage rate of the automated watering system in the Tsinghua University Laboratory Animal Resources Center is significantly lower than the theoretical design rate of 0.003%, which demonstrates the system's safety and effectiveness. Additionally, the adoption of an automated watering system can significantly enhance caretaking efficiency. While initial investments in the system are required, the subsequent increase in efficiency leads to a continuous decrease in labor costs, thereby reducing the total operational expenses of the facility. In the context of modernizing animal facility construction, automated watering systems are becoming an essential consideration in facility design and operation.

Objective:To explore the locations of the lumbosacral nerve roots by use of the magnetic stimulation.Methods:Thirty healthy subjects were studied. The projections of the right L 2 to S 1 intervertebral foramina on their body surfaces were determined manually with ultrasound assistance. Magnetic stimulation was applied to different nerve root segments to induce compound muscle action potentials (CMAP) in the vastus medialis, tibialis anterior, and gastrocnemius muscles of the lower limbs. The changes in latency, amplitude, and motor threshold were observed. Results:Magnetic stimulation on the L 2-L 3 segment resulted in a significant direct excitation of the vastus medialis. That on the L 5-S 1 segment evoked a significant direct excitatory effect on the tibialis anterior and gastrocnemius, with a motor threshold below 40%, an amplitude exceeding 1mV, and many effective responses. However, during the magnetic stimulation on the L 4 segment, the amplitude of the vastus medialis was above 1mV, with no significant differences in the number of effective responses among the muscle groups. Moreover, there was a stepwise change in the latency of effective muscle responses to magnetic stimulation at different segments. The CMAP latencies of 12+ ms for the tibialis anterior and 13+ ms for the gastrocnemius indicated activation of the L 5 and L 4 nerve roots, respectively, while those of 6+ ms, 7+ ms, and 8+ ms for the vastus medialis suggested activation of the L 4, L 3, and L 2 nerve roots, respectively. Conclusions:Based on the responses (CMAP latency, amplitude and motor threshold) of the vastus medialis, tibialis anterior and gastrocnemius to magnetic stimulation at different L 2 to S 1 segments, the spinal nerve root segments responsible for innervation can be inferred.

Objective:To explore the ability of sequential immunization regimen inducing neutralizing antibodies against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) Wuhan-Hu1 and Omicron variants in mice.Methods:Groups of 6-8-week-old BALB/c mice were primed with two doses of Wuhan-Hu-1 inactivated vaccine, and then boosted with Omicron or Wuhan-Hu-1 inactivated vaccine, respectively. Binding antibodies were tested by enzyme linked immunosorbent assay; and neutralizing antibodies against Wuhan-Hu1 and Omicron variants were analyzed by vesicular stomatitis virus pseudovirus assay system; SARS-CoV-2 specific cellular immune responses were quantified by enzyme-linked immunosorbent spot assay.Results:IgG antibodies against Wuhan-Hu1, Delta and Omicron RBD were enhanced after the second dose of Wuhan-Hu1 inactivated vaccine. Compared with Wuhan-Hu1 inactivated vaccine, the group boosted with Omicron inactivated vaccine improved Wu-RBD and Omic-RBD specific IgG antibodies 1.41 and 1.26 times, and serum neutralizing antibodies against BA.1, BA.2, BA.4/5 and BF.7 were elevated 4.5, 3.4, 12.1 and 6.5 folds, respectively, by sequential immunization. After booster immunization with inactivated Wuhan-Hu1 or Omicron vaccines, Wu-RBD IgA titer was significantly higher than that of one dose inactivated Wuhan-Hu1 vaccine ( P=0.005 7, P=0.006 1). Conclusions:Neutralizing antibodies against Omicron variants were enhanced by sequential immunization with Omicron inactivated vaccine. Specific IgA was significantly enhanced after the third dose of inactivated vaccine.

Background Paraquat (PQ) is a widely used herbicide that exerts neurotoxicity. The effects of PQ on neural stem cells (NSCs) through microglia mediated neuroinflammation remain limitedly studied. Objective To investigate the effects of PQ on the proliferation and neurogenesis of NSCs through neuroinflammation mediated by microglia. Methods Microglial cell lines (BV2 cells) and primary NSCs were used. BV2 cells were exposed to 0, 1, 3.3, 10, 33, and 100 μmol·L⁻¹ of PQ for 6 h followed by viability assessment. The highest PQ concentration that had no effect on cell viability was selected as the final exposure concentration (33 μmol·L⁻¹). To exclude the direct effect of PQ on NSCs, after the BV2 cells were cultured in complete medium containing 33 μmol·L⁻¹ PQ for 6 h, the BV2 culture medium was replaced by NSCs complete medium without PQ for 24 h. The concentration of interleukin-1β (IL-1β) in supernatant was detected by enzyme-linked immune sorbent assay. Besides, in order to detect the effects of IL-1β on NSCs proliferation and neurogenesis, NSCs isolated from hippocampus of adult mice were cultured in the supernatant obtained above and divided into four groups: control supernatant + control antibody, control supernatant + IL-1β neutralizing antibody (10 ng·mL⁻¹), PQ supernatant + control antibody, PQ supernatant + IL-1β neutralizing antibody (10 ng·mL⁻¹). Proportion of Ki67-positive NSCs was detected by flow cytometry (FCS) and immunofluorescence after 24 h culture, and neurogenesis was detected by FCS and immunofluorescence after 3-7 d of culture. Results The IL-1β concentration in the supernatant of BV2 cells was significantly increased after the 33 μmol·L⁻¹ PQ exposure compared with the control group (t=3.020, P<0.05). After the NSCs were cultured with the supernatant of PQ-treated BV2 cells, the proportion of Ki67-positive NSCs (t=9.129, P<0.01) and the proportion of newborn neurons (t=4.638, P<0.01) were significantly decreased compared to the control group. After neutralizing IL-1β, the proportion of Ki67-positive NSCs (t=22.05, P<0.01) and the proportion of newborn neurons (t=11.09, P<0.01) were significantly higher than those in the un-neutralized group. The results of immunofluorescence detection also showed that after neutralizing IL-1β secreted by 33 μmol·L⁻¹ PQ-treated BV2 cells, the number of Ki67-positive NSCs and the number of newborn neurons were significantly higher than those in the un-neutralized group. Conclusion The secretion of IL-1β by microglia is increased after PQ treatment, resulting in a decrease in the proliferation and neurogenesis of NSCs. These results suggest that neuroinflammation is involved in NSCs damage caused by PQ.

Objective:To evaluate the teaching effectiveness of independent experimental design from students' active learning behavior, and further provide the basis for advancing the reform of functional experimental teaching and teaching quality.Methods:In June 2019, 186 undergraduates (5-year-programme and 8-year-programme) of Xiangya School of Medicine were included in the teaching research. Self-administered questionnaires were applied to characterize students' active learning behavior in independent experimental design education. Spearman rank correlation analysis and Logistic regression analysis were used in the study. SPSS 23.0 was used for descriptive analysis of the data.Results:During the independent experimental design, 85.0%(158/186) of the students thought it was necessary and important to conduct independent experimental design education; 72.6%(135/186) of the students tentatively raised new scientific questions; 97.8%(182/186) of the students actively searched literature; 77.4%(144/186) of the students participated in reply positively. The value of correlation coefficient of actively learning behavior "tentatively raising new science questions" and teaching effectiveness "improving the ability of scientific thinking" was 0.81. And only 42.5%(79/186) of the students agreed that students needed to summarize after reporting.Conclusion:Independent experimental design education is welcomed and widely accepted by students, which has effectively improved the capacity for scientific research and innovation spirit of students. Whether students' active learning behavior can be fully mobilized in the education practice is closely related to the teaching effect. And the cultivation of leadership and leading consciousness still need to be improved.

Hepatocellular carcinoma (HCC) is a common malignant tumor with poor prognosis and high mortality. In this study, we demonstrated a novel vaccine targeting HCC and tumor neovascular endothelial cells by fusing recombinant MHCC97H cells expressing porcine α-1,3-galactose epitopes (αGal) and endorphin extracellular domains (END) with dendritic cells (DCs) from healthy volunteers. END⁺/Gal⁺-MHCC97H/DC fusion cells induced cytotoxic T lymphocytes (CTLs) and secretion of interferon-gamma (IFN-γ). CTLs targeted cells expressing αGal and END and tumor angiogenesis. The fused cell vaccine can effectively inhibit tumor growth and prolong the survival time of human hepatoma mice, indicating the high clinical potential of this new cell based vaccine.

ObjectiveTo explore the effect of early individualized rehabilitation on patients with severe mechanical ventilation. MethodsA total of 36 patients on mechanical ventilation admitted to the ICU of the Second Affiliated Hospital of Anhui Medical University from March, 2019 to February, 2020 were randomly divided into control group (n = 18) and rehabilitation group (n = 18). All the patients completed a rehabilitation assessment within 24 hours of admission, including clinical assessment, state of consciousness and muscle strength assessment. The control group was treated with intensive care routine treatment, including symptomatic treatment of primary disease, nutritional support, placement of normal limbs, active and passive movement of limbs. The rehabilitation group received early individualized rehabilitation in addition., including active and passive limb movements, transfer training, physical factor therapy, and respiratory muscle training after the specific evaluation. The mechanical ventilation duration and ICU length of stay, the hospitalization cost, Richmond Agitation and Sedation Scale (RASS), acute Physiology and Chronic Health Evaluation Ⅱ (APACHEⅡ), and the content of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-8 were compared. ResultsThere was no significant difference in the weaning rate and hospitalization cost between two groups (P > 0.05). The mechanical ventilation duration and ICU length of stay were less in the rehabilitation group than in the control group (t > 2.067, P < 0.05). After treatment, the score of APACHEⅡ and the content of TNF-α and IL-6 decreased in the control group (t > 2.040, P < 0.05); the score of APACHEⅡ and the content of TNF-α, IL-6 and IL-8 decreased in the rehabilitation group (t > 4.141, P < 0.001); the content of TNF-α, IL-6 and IL-8 was less in the rehabilitation group than in the control group (t > 2.217, P < 0.05). The improvement of all the indexes was better in the rehabilitation group than in the control group (|Z| > 2.104, P < 0.05). ConclusionFor patients on mechanical ventilation, early individualized rehabilitation could improve the sedation, relieve the inflammatory reaction, accelerate the process of weaning, and reduce the length of stay with no extra cost.