Objective To establish an acute rejection model of cervical heart transplantation in mice and evaluate the survival and dynamic rejection process post-transplantation. Methods Mice were randomly divided into sham operation group (n=10), syngeneic transplantation group (n=21), and allogeneic transplantation group (n=65). Sham operation, syngeneic cervical heart transplantation, and allogeneic cervical heart transplantation were performed respectively. The survival of recipient mice and grafts, histopathological changes of graft tissues, subpopulations of splenic lymphocytes, and expression of inflammatory factors in serum and grafts were observed. Results The survival rate and graft survival rate of the sham operation group and syngeneic transplantation group were 100% at 7 days after surgery. In the allogeneic transplantation group, 5 cases failed and died on the first day after surgery. The survival rate at 7 days after surgery was 86%, and all surviving mice had grafts that stopped beating at 7 days after surgery. The allogeneic transplantation group showed significant rejection at 7 days after surgery, accompanied by tissue damage and CD8⁺ T cell infiltration. The proportion of CD8⁺ T cells in the spleen continued to rise post-operation, while the proportion of CD4⁺ T cells showed a downward trend. The expression of interferon-γ in serum and grafts peaked at 5 days after surgery, while the expression of tumor necrosis factor-α showed no statistical significance. Conclusions Acute rejection following heart transplantation in mice intensifies between 5 to 7 days after surgery, which may be a critical time window for immunological intervention.

OBJECTIVE: To explore the effectiveness of additional anti-rotation steel plate assisted intramedullary nail technology in treatment of aseptic femoral non-union patients. METHODS: A retrospective analysis was conducted on 21 patients with aseptic femoral non-union who admitted between September 2020 and October 2024 and treated with additional anti-rotation steel plate assisted intramedullary nail technology. There were 17 males and 4 females, aged 25-67 years (mean, 44 years). There were 19 cases of femoral anterograde intramedullary nail fixation, 1 case of femoral retrograde intramedullary nail fixation, and 1 case of steel plate fixation with fatigue fracture. There were 9 cases of hypertrophic non-union and 12 cases of atrophic non-union. All patients had varying degrees of fracture end atrophy/sclerosis. Among them, 20 patients who were fixed with intramedullary nails underwent removal of soft tissue and hardened bone at the fracture end, and cortical treatment resulted in the appearance of "chili sign" at the fracture end. Iliac bone grafting and anti-rotation steel plate fixation were performed. One patient with steel plate fixation was removed the steel palte and fixed with a retrograde intramedullary nail, while the hardened bone at the fracture end was removed, iliac bone grafting and anti-rotation steel plate fixation were performed. Postoperative follow-up observation included the incision healing, maximum knee flexion range of motion, bone healing, length of lower limbs, and subjective satisfaction. The lower extremity functional scale (LEFS) score was used to evaluate the lower limb function. RESULTS: All incisions healed by first intention. All patients were followed up 7-26 months (mean, 15.5 months). At last follow-up, the femoral fracture healed with the obvious callus formation at the fracture end; the maximum knee flexion range of motion was 95°-127° (mean, 112.67°). The LEFS score increased from 29.9±6.7 before operation to 75.9±3.0 at last follow-up, and the difference was significant (t=-29.622, P<0.001). Except for 1 patient who underwent intramedullary nail dynamic treatment before operation and had a lower limb shortening of about 0.9 cm, the other patients had bilateral lower limbs of equal length. All patients had no postoperative infections, mal-union of fractures, deep vein thrombosis, joint stiffness, or other complications. CONCLUSION The use of additional anti-rotation steel plate assisted intramedullary nail technology in the treatment of aseptic femoral non-union not only overcomes the drawbacks of insufficient stability at the fracture end of intramedullary nails, but also overcomes the shortcomings of biased fixation with steel plates. It has the advantages of minimal trauma, effective maintenance of fracture stability, and ideal postoperative functional recovery, making it an effective treatment for aseptic femoral non-union.
Humans ; Male ; Fracture Fixation, Intramedullary/instrumentation* ; Female ; Bone Plates ; Middle Aged ; Adult ; Femoral Fractures/surgery* ; Retrospective Studies ; Bone Nails ; Aged ; Fractures, Ununited/surgery* ; Treatment Outcome ; Bone Transplantation/methods* ; Steel ; Fracture Healing

OBJECTIVE: To identify protein markers that may be associated with ulcerative colitis (UC) by analyzing differential proteins in the salivary exosomes from newly diagnosed patients with active UC and healthy controls (HC), and to investigate the function of salivary exosome-specific high-expression proteins in UC patients and their potential role in the pathogenesis of UC. METHODS: All patients and healthy controls were recruited from Peking University People' s Hospital. Whole saliva was obtained from 37 patients with newly diagnosed active ulcerative colitis (n=37) and apparently healthy controls (n=10). Salivary exosomes were extracted from samples, and the proteins within the exosomes were identified by liquid chromatograph-mass spectrometer (LC-MS/MS). The differentially expressed protein genes underwent gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis using the DAVID tool. In vitro, macrophages were co-cultured with salivary exosomes from UC group and those from HC group, respectively, and real-time quantitative polymerase chain reaction (qPCR) was used to detect levels of CD80⁺ and CD86⁺. Additionally, ELISA was performed to measure secretion levels of interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) in the cell supernatant. RESULTS: A total of 259 proteins were co-expressed in saliva exosomes from UC group and HC group, among which 11 proteins were highly expressed in the UC group, including PDIA4, A2M, EEF2, C3, PSMA2, PSMB6, PSMA1, IGHG1, IGHG3, IGHG4 and SERPING1, while 4 proteins were lowly expressed in UC group, including TCN1, SLPI and SERPING. Functional analysis of these 15 proteins, along with 129 specific proteins found only in the UC patients and 69 specific proteins found only in HC patients, respectively, was conducted using GO/KEGG. The results revealed that in the UC group, proteasome-related proteins such as PSMA1, PSMA2 and PSMB6 expressions were increased in salivary exosomes while many key molecules involved in complement cascade pathways, such as C3 were up-regu-lated. In vitro co-culture experiments demonstrated that compared with healthy controls, the salivary exosomes of the UC patients in active stage could play a pro-inflammatory role by promoting the transformation of macrophages into M1 type cells that secrete inflammatory factors IL-1β, IL-6 and TNF-α. CONCLUSION Salivary exosomes in the UC patients may have the function of promoting inflammation. Analysis of protein levels in the saliva of the UC patients and healthy controls revealed significant differences in the expression levels of 15 co-expressed proteins between the two groups. Among them, C3, PSMA2, PSMB6 and PSMA1 were found to be mainly related to immune and inflammatory reactions in the UC group. These findings suggest that proteins with high specific expression in salivary exosomes of the UC patients have the potential to be used as a disease marker for UC diagnosis and may contribute to the pathogenesis of UC.
Humans ; Colitis, Ulcerative/metabolism* ; Exosomes/metabolism* ; Saliva/metabolism* ; Biomarkers/analysis* ; Male ; Female ; Adult ; Case-Control Studies ; Interleukin-6/metabolism* ; Middle Aged

The liver regenerative capacity is crucial for patients with end-stage liver disease following partial hepatectomy (PHx). The specific bacteria and mechanisms regulating liver regeneration post-PHx remain unclear. This study demonstrated dynamic changes in the abundance of Parabacteroides distasonis (P. distasonis) post-PHx, correlating with hepatocyte proliferation. Treatment with live P. distasonis significantly promoted hepatocyte proliferation and liver regeneration after PHx. Targeted metabolomics revealed a significant positive correlation between P. distasonis and β-hydroxybutyric acid (BHB), as well as hyodeoxycholic acid and 3-hydroxyphenylacetic acid in the gut after PHx. Notably, treatment with BHB, but not hyodeoxycholic acid or 3-hydroxyphenylacetic acid, significantly promoted hepatocyte proliferation and liver regeneration in mice after PHx. Moreover, STAT3 inhibitor Stattic attenuated the promotive effects of BHB on cell proliferation and liver regeneration both in vitro and in vivo. Mechanistically, P. distasonis upregulated the expression of fatty acid oxidation-related proteins, and increased BHB levels in the liver, and then BHB activated the STAT3 signaling pathway to promote liver regeneration. This study, for the first time, identifies the involvement of P. distasonis and its associated metabolite BHB in promoting liver regeneration after PHx, providing new insights for considering P. distasonis and BHB as potential strategies for promoting hepatic regeneration.

Although a single nucleotide polymorphism for N-acetyltransferase 10 (NAT10) has been identified in patients with early-onset stroke, the role of NAT10 in ischemic injury and the related underlying mechanisms remains elusive. Here, we provide evidence that NAT10, the only known RNA N4-acetylcytidine (ac4C) modification "writer", is increased in the damaged cortex of patients with acute ischemic stroke and the peri-infarct cortex of mice subjected to photothrombotic (PT) stroke. Pharmacological inhibition of NAT10 with remodelin on Days 3-7 post-stroke or astrocytic depletion of NAT10 via targeted virus attenuates ischemia-induced infarction and improves functional recovery in PT mice. Mechanistically, NAT10 enhances ac4C acetylation of the inflammatory cytokine tissue inhibitor of metalloproteinase 1 (Timp1) mRNA transcript, which increases TIMP1 expression and results in the accumulation of microtubule-associated protein 1 light chain 3 (LC3) and progression of astrocyte autophagy. These findings demonstrate that NAT10 regulates astrocyte autophagy by targeting Timp1 ac4C after stroke. This study highlights the critical role of ac4C in the regulation of astrocyte autophagy and proposes a promising strategy to improve post-stroke outcomes via NAT10 inhibition.

The prefrontal cortex (PFC) plays a pivotal role in orchestrating higher-order emotional and cognitive processes, a function that depends on the precise modulation of synaptic activity. Although pharmacological studies have demonstrated that dopamine signaling through dopamine D1 receptor (DRD1) in the PFC is essential for these functions, the cell-type-specific and molecular mechanisms underlying the neuromodulatory effects remain elusive. Using cell-type-specific knockout mice and patch-clamp recordings, we investigated the regulatory role of DRD1 on neurons and astrocytes in synaptic transmission and plasticity. Furthermore, we explored the mechanisms by which DRD1 on astrocytes regulate synaptic transmission and plasticity at the cellular level, as well as emotional and cognitive functions at the behavioral level, through two-photon imaging, microdialysis, high-performance liquid chromatography, transcriptome sequencing, and behavioral testing. We found that conditional knockout of the Drd1 in astrocytes (CKO^AST) increased glutamatergic synaptic transmission and long-term potentiation (LTP) in the medial prefrontal cortex (mPFC), whereas Drd1 deletion in pyramidal neurons did not affect synaptic transmission. The elevated level of d-serine in the mPFC of CKO^AST mice increased glutamatergic transmission and LTP through NMDA receptors. In addition, CKO^AST mice exhibited abnormal emotional and cognitive function. Notably, these behavioral changes in CKO^AST mice could be reversed through the administration of d-serine degrease to the mPFC. These results highlight the critical role of the astrocytic DRD1 in modulating mPFC synaptic transmission and plasticity, as well as higher brain functions through d-serine, and may shed light on the treatment of mental disorders.

ObjectiveTo investigate the effect and potential mechanism of Dihuangyin on 2， 4-dinitrochlorobenzene （DNCB） -induced model mice with atopic dermatitis （AD）. MethodA mouse model with AD was established by repeatedly stimulating the back skin of mice with DNCB. After successful modeling， the mice were randomly divided into model group， Runzao group （0.78 g·kg^-1）， and high， medium， and low dose （40.30， 20.15， and 10.08 g·kg^-1） groups of Dihuangyin， with 12 mice in each group， and the blank group consisted of 12 mice， 72 in total. The administration groups were given the corresponding liquid by dose， and the blank group and model group were given the same dose of pure water by intragastric administration， once a day. The skin lesions and scratching times of mice were observed after continuous administration for two weeks. The back skin lesions of mice were stained with hematoxylin-eosin （HE） and toluidine blue to observe the pathology. The contents of serum immunoglobulin E （IgE）， interleukin-4 （IL-4）， interleukin-6 （IL-6）， and interferon-γ （IFN-γ） were detected by enzyme-linked immunosorbent assay （ELISA）. The mRNA expression levels of IFN-γ， IL-4， IL-6， Janus kinase 1 （JAK1）， and transcriptional activator 3 （STAT3） in skin lesion tissue were detected by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. The expressions of JAK1， phosphorylation（p）-JAK1， STAT3， and p-STAT3 proteins in skin lesion tissue were detected by Western blot. ResultCompared with the blank group， the back skin of the model group showed large-scale scab， dryness， erosion， hypertrophy with scratching， epidermal hyperplasia with hyperkeratosis and parakeratosis， hyperacanthosis with edema， and a large number of mast cell infiltration in the dermis， some of which were degranulated. The contents of IgE， IL-4， IL-6， and IFN-γ in the serum of mice were significantly increased （P<0.01）， and the protein expression levels of p-JAK1， STAT3， and p-STAT3 and mRNA expressions of IL-4， IL-6， IFN-γ， JAK1， and STAT3 in skin lesion tissue were significantly increased （P<0.01）. Compared with the model group， only a small amount of dryness and desquamation were observed in the back skin of mice in each administration group， and cell edema was reduced. The inflammatory infiltration was significantly reduced， and the number of mast cell infiltration was significantly decreased. The serum IgE， IL-4， IL-6， and IFN-γ of mice were decreased to varying degrees （P<0.05， P<0.01）. The protein expression levels of p-JAK1， STAT3， and p-STAT3 and mRNA expressions of IL-4， IL-6， IFN-γ， JAK1， and STAT3 in skin lesion tissue were significantly decreased， and the effect of high dose group of Dihuangyin was the best （P<0.01）. ConclusionDihuangyin can improve skin lesions and pruritus in mice with AD， and its mechanism may be related to the effective regulation of cytokines on the helper T cells （Th1）/Th2 axis by interfering with the JAK1/STAT3 signaling pathway and affecting skin barrier function.

Macroautophagy (referred to as autophagy hereafter) is a major intracellular lysosomal degradation pathway that is responsible for the degradation of misfolded/damaged proteins and organelles. Previous studies showed that autophagy protects against acetaminophen (APAP)-induced injury (AILI) via selective removal of damaged mitochondria and APAP protein adducts. The lysosome is a critical organelle sitting at the end stage of autophagy for autophagic degradation via fusion with autophagosomes. In the present study, we showed that transcription factor EB (TFEB), a master transcription factor for lysosomal biogenesis, was impaired by APAP resulting in decreased lysosomal biogenesis in mouse livers. Genetic loss-of and gain-of function of hepatic TFEB exacerbated or protected against AILI, respectively. Mechanistically, overexpression of TFEB increased clearance of APAP protein adducts and mitochondria biogenesis as well as SQSTM1/p62-dependent non-canonical nuclear factor erythroid 2-related factor 2 (NRF2) activation to protect against AILI. We also performed an unbiased cell-based imaging high-throughput chemical screening on TFEB and identified a group of TFEB agonists. Among these agonists, salinomycin, an anticoccidial and antibacterial agent, activated TFEB and protected against AILI in mice. In conclusion, genetic and pharmacological activating TFEB may be a promising approach for protecting against AILI.

BACKGROUND:The biological behavior of mesenchymal stem cells is influenced by the survival microenvironment.Pre-treatment of the microenvironment is an important means of regulating the function of mesenchymal stem cells. OBJECTIVE:To compare the differences in paracrine function of umbilical cord mesenchymal stem cells and adipose mesenchymal stem cells under oxidative stress and hypoxia,and to provide a theoretical basis for selecting appropriate pretreatment of mesenchymal stem cells to treat different diseases. METHODS:Umbilical cord mesenchymal stem cells and adipose mesenchymal stem cells were cultured by H2O2 or O2 oxygen,respectively,and cell morphology,proliferation,viability and paracrine factor expression were examined. RESULTS AND CONCLUSION:(1)The expression levels of brain-derived neurotrophic factor and transforming growth factor-β were higher in umbilical cord mesenchymal stem cells than in adipose mesenchymal stem cells under a normal culture environment,while the expressions of stromal cell-derived factor-1α and tumor necrosis factor stimulating factor-6 in the adipose mesenchymal stem cells were significantly higher than those in the umbilical cord mesenchymal stem cells.(2)There was no significant difference in the effect of low and moderate levels(≤100 μmol/L)of H2O2 on the viability of the two mesenchymal stem cells.However,increasing the H2O2 concentration from 50 μmol/L to 100 μmol/L resulted in a distinct increase in vascular endothelial growth factor expression in umbilical cord mesenchymal stem cells.The expression of basic fibroblast growth factor,vascular endothelial growth factor,stromal cell-derived factor-1α and interleukin-10 in adipose mesenchymal stem cells was greatly increased by increasing H2O2 concentration in this range.(3)1%O2 hypoxia promoted mesenchymal stem cell proliferation.After 24 hours of culture in 1%O2,gene expression levels were elevated in both mesenchymal stem cells,but the expression levels of vascular endothelial growth factor,interleukin-10 and tumor necrosis factor stimulating factor-6 were significantly higher in adipose mesenchymal stem cells than in umbilical cord mesenchymal stem cells.(4)It is concluded that hypoxia and oxidative stress preconditioning enhances the paracrine function of mesenchymal stem cells.However,mesenchymal stem cells respond differently to hypoxia and oxidative stress.Treating diseases can choose suitable mesenchymal stem cells for appropriate pretreatment to further enhance their therapeutic potential.

Objective To evaluate the measurement uncertainty of endocrine test items by"top-down"method.Methods The"top-down"method in the technical report of CNAS-CL01-G003:2021"Medical Laboratory-Evaluation and Expression of Measurement Uncertainty"was used,collecting the laboratory's internal quality control data and the external quality assurance results of Beijing Clinical Laboratory Center from 2019 to 2021.To evaluate the measurement uncertainty of 11 endocrine tests including free triiodothyronine(FT3),total triiodothyronine(TT3)and free thyroxine(FT4).Results The relative expanded uncertainties of 11 endocrine test items in laboratory were FT3:12.658％,TT3:13.372％,FT4:10.468％,total thyroxine(TT4):32.382％,thyroid stimulating hormone(TSH):8.594％,estradiol(E2):18.656％,follicle-stimulating hormone(FSH):14.650％,luteinizing hormone(LH):29.384％,progesterone(PRO):28.806％,prolactin(PRL):13.810％and testosterone(TESTO):31.610％.At the normal concentration level,the relative expanded uncertainties were FT3:12.424％,TT3:12.462％,FT4:8.606％,TT4:14.130％,TSH:12.536％,E2:19.586％,FSH:14.382％,LH:23.400％,PRO:38.346％,PRL:16.014％and TESTO:39.352％.The relative expanded uncertainties at high concentration levels are FT3:13.882％,TT3:14.096％,FT4:11.040％,TT4:8.614％,TSH:7.782％,E2:14.366％,FSH:13.436％,LH:14.804％,PRO:11.574％,PRL:17.742％,TESTO:39.322％.The relative extended measurement uncertainty of TT4,LH near low concentration levels,PRO near low and normal concentration levels,and TESTO near three concentration levels was higher than the target uncertainty(25％),and the remaining items are less than the target uncertainty.Conclusion The quality control data in the laboratory can reflect the measurement uncertainty of 11 endocrine detection items including FT3,TT3 and FT4 in Abbott i2000SR automatic chemiluminescence immunoassay analyzer,which has important clinical application value.