OBJECTIVE: To prepare decellularized nerve grafts from alpha-1, 3-galactosyltransferase (GGTA1) gene-edited pigs and explore their biocompatibility for xenotransplantation. METHODS: The sciatic nerves from wild-type pigs and GGTA1 gene-edited pigs were obtained and underwent decellularization. The alpha-galactosidase (α-gal) content in the sciatic nerves of GGTA1 gene-edited pigs was detected by using IB4 fluorescence staining and ELISA method to verify the knockout status of the GGTA1 gene, and using human sciatic nerve as a control. HE staining and scanning electron microscopy observation were used to observe the structure of the nerve samples. Immunofluorescence staining and DNA content determination were used to evaluate the degree of decellularization of the nerve samples. Fourteen nude mice were taken, and subcutaneous capsules were prepared on both sides of the spine. Decellularized nerve samples of wild-type pigs ( n=7) and GGTA1 gene-edited pigs ( n=7) were randomly implanted in the subcutaneous capsules. Blood was drawn at 1, 3, 5, and 7 days after implantation to detect neutrophil counting. RESULTS: IB4 fluorescence staining and ELISA detection showed that GGTA1 gene was successfully knocked out in the nerves of GGTA1 gene-edited pigs. HE staining showed that the structure of the decellularized nerve from GGTA1 gene-edited pigs was well preserved; the nerve basement membrane tube structure was visible under scanning electron microscopy; no cell nuclei was observed, and the extracellular matrix components was retained in the nerve grafts by immunofluorescence staining; and the DNA content was significantly reduced when compared with the normal nerves ( P<0.05). In vivo experiments showed that the number of neutrophils in the two groups were similar at 1, 3, and 7 days after implantation, with no significant difference ( P>0.05); only at 5 days, the number of neutrophils was significantly lower in the GGTA1 gene-edited pigs than in the wild-type pigs ( P<0.05). CONCLUSION The decellularized nerve grafts from GGTA1 gene-edited pigs have well-preserved nerve structure, complete decellularization, retain the natural nerve basement membrane tube structure and components, and low immune response after xenotransplantation through in vitro experiments.
Animals ; Transplantation, Heterologous ; Galactosyltransferases/genetics* ; Sciatic Nerve/immunology* ; Swine ; Tissue Engineering/methods* ; Humans ; Graft Rejection/prevention & control* ; Gene Editing ; Mice ; Mice, Nude ; Heterografts/immunology* ; Animals, Genetically Modified ; Tissue Scaffolds ; Decellularized Extracellular Matrix

OBJECTIVE: To explore the mechanism of antibiotic delivery system targeting bacterial biofilm with linezolid (LZD) based on ε-poly- L-lysine (ε-PLL) and cyclodextrin (CD) (ε-PLL-CD-LZD), aiming to enhance antibiotic bioavailability, effectively penetrate and disrupt biofilm structures, and thereby improve the treatment of bone and joint infections. METHODS: ε-PLL-CD-LZD was synthesized via chemical methods. The grafting rate of CD was characterized using nuclear magnetic resonance. In vitro biocompatibility was evaluated through live/dead cell staining after co-culturing with mouse embryonic osteoblast precursor cells (MC3T3-E1), human umbilical vein endothelial cells, and mouse embryonic fibroblast cells (3T3-L1). The biofilm-enrichment capacity of ε-PLL-CD-LZD was assessed using Staphylococcus aureus biofilms through enrichment studies. Its biofilm eradication efficacy was investigated via minimum inhibitory concentration (MIC) determination, scanning electron microscopy, and live/dead bacterial staining. A bone and joint infection model in male Sprague-Dawley rats was established to validate the antibacterial effects of ε-PLL-CD-LZD. RESULTS: In ε-PLL-CD-LZD, the average grafting rate of CD reached 9.88%. The cell viability exceeded 90% after co-culturing with three types cells. The strong biofilm enrichment capability was observed with a MIC of 2 mg/L. Scanning electron microscopy observations revealed the effective disruption of biofilm structure, indicating potent biofilm eradication capacity. In vivo rat experiments demonstrated that ε-PLL-CD-LZD significantly reduced bacterial load and infection positivity rate at the lesion site ( P<0.05). CONCLUSION The ε-PLL-CD antibiotic delivery system provides a treatment strategy for bone and joint infections with high clinical translational significance. By effectively enhancing antibiotic bioavailability, penetrating, and disrupting biofilms, it demonstrated significant anti-infection effects in animal models.
Biofilms/drug effects* ; Animals ; Anti-Bacterial Agents/pharmacology* ; Polylysine/chemistry* ; Cyclodextrins/administration & dosage* ; Humans ; Linezolid/pharmacology* ; Staphylococcus aureus/physiology* ; Rats, Sprague-Dawley ; Mice ; Rats ; Male ; Drug Delivery Systems ; Staphylococcal Infections/drug therapy* ; Microbial Sensitivity Tests ; Human Umbilical Vein Endothelial Cells ; Osteoblasts/cytology*

OBJECTIVE: To investigate the effects of removing microglia from spinal cord on nerve repair and functional recovery after spinal cord injury (SCI) in mice. METHODS: Thirty-nine 6-week-old female C57BL/6 mice were randomly divided into control group ( n=12), SCI group ( n=12), and PLX3397+SCI group ( n=15). The PLX3397+SCI group received continuous feeding of PLX3397, a colony-stimulating factor 1 receptor inhibitor, while the other two groups were fed a standard diet. After 14 days, both the SCI group and the PLX3397+SCI group were tested for ionized calcium binding adapter molecule 1 (Iba1) to confirm that the PLX3397+SCI group had completely depleted the spinal cord microglia. The SCI model was then prepared by clamping the spinal cord in both the SCI group and the PLX3397+SCI group, while the control group underwent laminectomy. Preoperatively and at 1, 3, 7, 14, 21, and 28 days postoperatively, the Basso Mouse Scale (BMS) was used to assess the hind limb function of mice in each group. At 28 days, a footprint test was conducted to observe the gait of the mice. After SCI, spinal cord tissue from the injury site was taken, and Iba1 immunofluorescence staining was performed at 7 days to observe the aggregation and proliferation of microglia in the spinal cord. HE staining was used to observe the formation of glial scars at the injury site at 28 days; glial fibrillary acidic protein (GFAP) immunofluorescence staining was applied to astrocytes to assess the extent of the injured area; neuronal nuclei antigen (NeuN) immunofluorescence staining was used to evaluate neuronal survival. And 5-hydroxytryptamine (5-HT) immunofluorescence staining was performed to assess axonal survival at 60 days. RESULTS: All mice survived until the end of the experiment. Immunofluorescence staining revealed that the microglia in the spinal cord of the PLX3397+SCI group decreased by more than 95% compared to the control group after 14 days of continuous feeding with PLX3397 ( P<0.05). Compared to the control group, the BMS scores in the PLX3397+SCI group and the SCI group significantly decreased at different time points after SCI ( P<0.05). Moreover, the PLX3397+SCI group showed a further decrease in BMS scores compared to the SCI group, and exhibited a dragging gait. The differences between the two groups were significant at 14, 21, and 28 days ( P<0.05). HE staining at 28 days revealed that the SCI group had formed a well-defined and dense gliotic scar, while the PLX3397+SCI group also developed a gliotic scar, but with a more blurred and loose boundary. Immunofluorescence staining revealed that the number of microglia near the injury center at 7 days increased in the SCI group than in the control group, but the difference between groups was not significant ( P>0.05). In contrast, the PLX3397+SCI group showed a significant reduction in microglia compared to both the control and SCI groups ( P<0.05). At 28 days after SCI, the area of spinal cord injury in the PLX3397+SCI group was significantly larger than that in SCI group ( P<0.05); the surviving neurons significantly reduced compared with the control group and SCI group ( P<0.05). The axonal necrosis and retraction at 60 days after SCI were more obvious. CONCLUSION The removal of microglia in the spinal cord aggravate the tissue damage after SCI and affecte the recovery of motor function in mice, suggesting that microglia played a neuroprotective role in SCI.
Animals ; Spinal Cord Injuries/surgery* ; Microglia/pathology* ; Female ; Mice ; Mice, Inbred C57BL ; Nerve Regeneration/drug effects* ; Spinal Cord/pathology* ; Pyrroles/administration & dosage* ; Aminopyridines/administration & dosage* ; Recovery of Function ; Disease Models, Animal ; Calcium-Binding Proteins/metabolism* ; Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/antagonists & inhibitors* ; Microfilament Proteins/metabolism* ; Glial Fibrillary Acidic Protein/metabolism*

OBJECTIVE: To summarize the research progress of rodent models of secondary lymphedema (SL) and provide a reference for selecting appropriate animal models in SL research. METHODS: Recent literature on rodent SL models at home and abroad was comprehensively analyzed, summarizing model categories, development techniques, strengths, and weaknesses. RESULTS: Current research primarily utilizes rats and mice to establish SL models. The main model types include hind limb, forelimb, tail, and head/neck models. The hind limb model is the most frequently employed, typically requiring surgery combined with irradiation to induce stable chronic edema. Forelimb models primarily simulate upper limb lymphedema, but exhibit relatively rapid edema resolution. Tail models offer operational simplicity and are predominantly used for studying acute edema mechanisms and interventions; however, they demonstrate poor clinical relevance. Emerging head/neck models provide a valuable tool for investigating head and neck cancer-associated lymphedema. These models exhibit variations in lymphedema duration, degree of fibrosis, and edema incidences. CONCLUSION Existing models still fall short in faithfully replicating the chronicity, fibrosis, fat deposition, and complex microenvironment characteristic of human chronic lymphedema. Future research must integrate multidisciplinary approaches, optimize model construction strategies, and explore novel modeling approaches to more accurately mimic the human disease and advance SL prevention and treatment research.
Lymphedema/pathology* ; Animals ; Disease Models, Animal ; Rats ; Mice ; Humans ; Head and Neck Neoplasms/complications* ; Rodentia

OBJECTIVE: To investigate the effects of 4-methylcatechol (4MC) on the migration and inflammatory response in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS), as well as its underlying mechanisms of action. METHODS: RA-FLS was isolated from synovial tissue donated by RA patients, and the optimal concentration of 4MC was determined by cell counting kit 8 method for subsequent experiments, and the effect of 4MC on the migratory ability of RA-FLS was evaluated via a cell scratch assay. An inflammation model of RA-FLS was induced by tumor necrosis factor α (TNF-α). Real-time fluorescence quantitative PCR and ELISA were employed to detect the gene and protein expression levels of interleukin-1β (IL-1β) and IL-6 in RA-FLS and their culture supernatants, respectively, thereby investigating the anti-inflammatory effects of 4MC. Western blot was used to examine the expressions of nuclear factor κB (NF-κB) signaling pathway-related proteins, including inhibitor of NF-κB-α (IKBα), phosphorylated (P)-IκBα, NF-κB-inducing kinase α (IKKα), P-IKKαβ, P-p65, and p65. Cellular immunofluorescence was utilized to detect the expression and localization of p65 in RA-FLS, exploring whether 4MC exerts its anti-inflammatory effects by regulating the NF-κB signaling pathway. Finally, a collagen-induced arthritis (CIA) mouse model was established. The anti-RA effect of 4MC in vivo was evaluated by gross observation and histological examination. RESULTS: 4MC inhibited RA-FLS migration in a concentration-dependent manner. In the TNF-α-induced RA-FLS inflammation model, 4MC significantly decreased the gene and protein expression levels of IL-1β and IL-6. Furthermore, 4MC markedly reduced the ratios of P-IΚBα/IΚBα, P-IKKαβ/IKKα, and P-p65/p65, thereby blocking the transcriptional activity of p65 by inhibiting its nuclear translocation. This mechanism effectively suppressed the activation of the TNF-α-mediated NF-κB signaling pathway. Animal studies demonstrated that 4MC [10 mg/(kg·day)] significantly lowered serum levels of IL-1β, IL-6, and TNF-α, and alleviated arthritis severity and bone destruction in CIA mice. CONCLUSION 4MC not only inhibits the migration of RA-FLS but also mitigates their inflammatory response by suppressing the NF-κB signaling pathway, thereby effectively exerting its anti-RA effects.
Synoviocytes/metabolism* ; Arthritis, Rheumatoid/metabolism* ; Animals ; Cell Movement/drug effects* ; Humans ; Catechols/therapeutic use* ; Fibroblasts/drug effects* ; Mice ; Tumor Necrosis Factor-alpha/pharmacology* ; Interleukin-1beta/metabolism* ; Interleukin-6/metabolism* ; Signal Transduction/drug effects* ; NF-kappa B/metabolism* ; Transcription Factor RelA/metabolism* ; Synovial Membrane/cytology* ; Cells, Cultured ; Male ; Arthritis, Experimental ; Anti-Inflammatory Agents/pharmacology* ; NF-KappaB Inhibitor alpha ; Inflammation

OBJECTIVE: To explore the mechanism by which ω-3 polyunsaturated fatty acids (hereinafter referred to as "ω-3") exert antioxidant stress protection and promote osteogenic differentiation in MC3T3-E1 cells, and to reveal the relationship between ω-3 and the key antioxidant stress pathway involving nuclear factor E2-related factor 2 (Nrf2) and NAD (P) H quinone oxidoreductase 1 (NQO1) in MC3T3-E1 cells. METHODS: The optimal concentration of H ₂O ₂ (used to establish the oxidative stress model of MC3T3-E1 cells in vitro) and the optimal intervention concentrations of ω-3 were screened by cell counting kit 8. MC3T3-E1 cells were divided into blank control group, oxidative stress group (H ₂O ₂), low-dose ω-3 group (H ₂O ₂+low-dose ω-3), and high-dose ω-3 group (H ₂O ₂+high-dose ω-3). After osteoblastic differentiation for 7 or 14 days, the intracellular reactive oxygen species (ROS) level was measured by fluorescence staining and flow cytometry, and the mitochondrial morphological changes were observed by biological transmission electron microscope; the expression levels of Nrf2, NQO1, heme oxygenase 1 (HO-1), Mitofusin 1 (Mfn1), and Mfn2 were detected by Western blot to evaluate the cells' antioxidant stress capacity; the expression levels of Runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN) were detected by immunofluorescence staining and Western blot; osteogenic potential of MC3T3-E1 cells was evaluated by alkaline phosphatase (ALP) staining and alizarin red staining. RESULTS: Compared with the oxidative stress group, the content of ROS in the low and high dose ω-3 groups significantly decreased, and the protein expressions of Nrf2, NQO1, and HO-1 significantly increased ( P<0.05). At the same time, the mitochondrial morphology of MC3T3-E1 cells improved, and the expressions of mitochondrial morphology-related proteins Mfn1 and Mfn2 significantly increased ( P<0.05). ALP staining and alizarin red staining showed that the low-dose and high-dose ω-3 groups showed stronger osteogenic ability, and the expressions of osteogenesis-related proteins RUNX2 and OCN significantly increased ( P<0.05). And the above results showed a dose-dependence in the two ω-3 treatment groups ( P<0.05). CONCLUSION ω-3 can enhance the antioxidant capacity of MC3T3-E1 cells under oxidative stress conditions and upregulate their osteogenic activity, possibly through the Nrf2/NQO1 signaling pathway.
Oxidative Stress/drug effects* ; NF-E2-Related Factor 2/metabolism* ; NAD(P)H Dehydrogenase (Quinone)/metabolism* ; Animals ; Mice ; Osteogenesis/drug effects* ; Cell Differentiation/drug effects* ; Fatty Acids, Omega-3/pharmacology* ; Signal Transduction/drug effects* ; Osteoblasts/drug effects* ; Reactive Oxygen Species/metabolism* ; Cell Line ; Hydrogen Peroxide/pharmacology* ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Antioxidants/pharmacology* ; Heme Oxygenase-1/metabolism*

OBJECTIVE: To analyze the influences of dihydromyricetin on the proliferation and apoptosis of chondrocytes in osteoarthritis induced by hydrogen peroxide (H₂O₂) through reactive oxygen species (ROS)/p38 mitogen activated protein kinase (p38-MAPK) pathway. METHODS: Five C57BL/6J mice were euthanized by cervical dislocation after anesthesia. Chondrocytes were extracted and cultured.After passage, the chondrocytes were divided into control group, H2O2 group (0.8 μmol·L^-1 H₂O₂), dihydromyricetin low concentration group (0.8 μmol·L^-1 H₂O₂+20 μmol·L^-1 dihydromyricetin), dihydromyricetin high concentration group (0.8 μmol·L^-1 H₂O₂+80 μmol·L^-1 dihydromyricetin), and ROS inhibitor N-acetylcysteine (NAC) group (0.8 μmol·L^-1 H₂O₂+5 mmol·L^-1 NAC). The activity of chondrocytes was measured by methyl thiazolyl tetrazolium (MTT) assay. The apoptosis rate of chondrocytes was measured by Hoechst 33342 method. The level of ROS in chondrocytes was measured by 2, 7-dichlorofluorescein diacetate (DCFH-DA) fluorescence probe.The level of Type II collagen α1 (Col2α1) mRNA was measured by qRT-PCR.And the expression of Col2α1, p-p38-MAPK/p38-MAPK, B cell lymphoma gene-2 (Bcl-2) and Bcl-2 associated X protein (Bax) proteins was detected by Western blot. RESULTS: The chondrocytes showed swirling fibrous mass, and the expression of COL2α was positive. Compared with the control group, the chondrocyte viability, apoptosis rate, ROS fluorescence intensity, p-p38-MAPK/p38-MAPK, and the expression of Bax protein in H2O22 group increased, the level of Col2α1 mRNA, and the expression of Col2α1 and Bcl-2 proteins decreased (P<0.05). Compared with H₂O₂ group, the chondrocyte viability, apoptosis rate, ROS fluorescence intensity, p-p38-MAPK/p38-MAPK, and the expression of Bax protein in dihydromyricetin low concentration group, dihydromyricetin high concentration group, and NAC group decreased, the level of Col2α1 mRNA, and the expression of Col2α1 and Bcl-2 proteins increased (P<0.05). CONCLUSION Dihydromyricetin may inhibit chondrocyte apoptosis, inflammatory reaction and oxidative stress by inhibiting ROS/p38-MAPK pathway. Dihydromyricetin may be a potential drug for treating osteoarthritis.
Animals ; Chondrocytes/metabolism* ; Apoptosis/drug effects* ; Hydrogen Peroxide/toxicity* ; Osteoarthritis/physiopathology* ; Mice, Inbred C57BL ; Reactive Oxygen Species/metabolism* ; Mice ; Flavonols/pharmacology* ; p38 Mitogen-Activated Protein Kinases/genetics* ; Cell Proliferation/drug effects* ; Male ; Signal Transduction/drug effects* ; MAP Kinase Signaling System/drug effects* ; Cells, Cultured

OBJECTIVE: To explore the mechanism by which the extract of Semen Ziziphi Spinosae extract promotes bone growth in mice by modulation of the expression of miR-34a-5p in brain tissue. METHODS: Mice were assigned to four experimental groups:a normal control group, a drug administration group (receiving 0.320 mg·g^-1 body weight of Semen Ziziphi Spinosae extract via intragastric administration), a positive control group (receiving 0.013 mg·g^-1 body weight of jujube seed saponin via intragastric administration), and a combination group administration with Semen Ziziphi Spinosae extract plus a 5-hydroxytryptamine 2A receptor (5-HT2AR) agonist (intragastric administration of Semen Ziziphi Spinosae extract combined with intracerebroventricular injection of 8 μg P-MPPF per mice for the final three days of the experiment). Following a 20-day administration period, the effects of the interventions on bone growth, serum growth hormone (GH) levels, and 5-HT2AR expression in brain tissue were evaluated. MicroRNAs (miRNAs) that were differentially expressed in the brain tissues of mice exhibiting bone growth induced by Semen Ziziphi Spinosae extract, as compared to those in normal mice, were identified using a gene chip approach. The interaction between miR-34a-5p and 5-HT2AR was subsequently validated through quantitative reverse transcription polymerase chainreaction (RT-qPCR) and dual-luciferase reporter gene assays. Subsequently, by utilizing the miR-34a-5p inhibitor group and mimics group, along with the normal control group, the drug administration group, the positive control group, and the drug administration combined with miR-34a-5p inhibitor group, the variations in 5-HT2AR expression in mouse brain tissue across all groups were examined, and the binding activity of 5-hydroxytryptamine (5-HT) to the 5-hydroxytryptamine 1A receptor (5-HT1AR) in mice was assessed. RESULTS: The body lengths of the normal control group and the drug administration group were(8.9±0.3) and(10.4±0.4) cm;femur lengths were (8.5±0.3) and (9.1±0.5) mm;tibia lengths were (10.7±0.3) and (11.2±0.4) mm, respectively. The contents of GH levels were (58.6±8.2) and (72.9±6.1) ng·ml-1;and the contents of 5-HT2AR were (32.0±5.0) and (21.9± 5.5) ng·ml-1, respectively. Compared with the normal control group, the drug administration group promoted the growth of body length, femur, and tibia in mice, and increased GH secretion, showing statistically significant differences (P<0.05). Additionally, it significantly reduced the content of 5-HT2AR in brain tissue, with statistical significance (P<0.01). The gene chip analysis identified a total of 16 differentially expressed miRNAs, of which 13 were up-regulated and 3 were down-regulated. Bioinformatics analysis predicted that the up-regulated miR-34a-5p could regulate the expression of 5-HT2AR, a prediction that was confirmed through a dual-luciferase reporter gene assay, demonstrating a direct regulatory interaction between the two. Furthermore, in vivo experiments in mice revealed that overexpression and silencing of miR-34a-5p resulted in corresponding changes in the expression levels of 5-HT2AR in brain tissues/cells, as well as in the binding activity between 5-HT and 5-HT1AR. CONCLUSION The Semen Ziziphi Spinosae extract promotes animal bone growth by enhancing miR-34a-5p expression in brain tissue, downregulating the expression level of 5-HT2AR, improving the binding activity between 5-HT and 5-HT1AR, and extending slow-wave sleep duration, thereby stimulating GH secretion.
Animals ; MicroRNAs/metabolism* ; Mice ; Male ; Brain/metabolism* ; Ziziphus/chemistry* ; Bone Development/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Plant Extracts/pharmacology*

Objective The prevalence of drug-resistant Mycobacterium tuberculosis (Mtb) strains is exacerbating the global burden of tuberculosis (TB), highlighting the urgent need for new treatment strategies for TB. Methods The recombinant adenovirus vaccine expressing cyclic di-adenosine monophosphate (c-di-AMP) phosphodiesterase B (CnpB) (rAd-CnpB), was administered to normal mice via mucosal immunization, either alone or in combination with drug therapy, to treat Mtb respiratory infections in mice.Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of antibodies in serum and bronchoalveolar lavage fluid (BALF). Real-time quantitative PCR was performed to assess the transcription levels of cytokines interferon γ(IFN-γ) and interleukin 10(IL-10) in mouse lungs. Flow cytometry was used to determine the proportions of CD4⁺ and CD8⁺ T cell subsets in the lungs and spleens. ELISA was employed to measure the levels of cytokines IFN-γ, IL-2, IL-10, inflammatory factors IL-6, and tumor necrosis factor α (TNF-α) secreted by spleen cells following antigen stimulation. The bacteria loads in the lungs and spleens of Mtb-infected mice were enumerated by plate counting methods. Resluts Intranasal immunization with rAd-CnpB induced high titers of IgG in mouse serum and the production of IgG and IgA in BALF, along with alterations in T lymphocyte subsets in the lungs and spleens. Administration of rAd-CnpB, either alone or in combination with drugs, to Mtb-infected mice significantly increased serum IgG levels as well as IgA and IgG levels in BALF. rAd-CnpB immunization promoted the secretion of CnpB-specific cytokines and inflammatory factors by splenocytes in Mtb-infected mice. However, rAd-CnpB immunotherapy, either alone or combined with drugs, did not significantly affect the bacterial loads in the lungs and spleens of mice with Mtb respiratory infections. Conclusion Mucosal immunization with rAd-CnpB induced significant mucosal, humoral and cellular immune responses in mice, and significantly enhanced CnpB-specific cellular immune responses in Mtb-infected mice.
Animals ; Adenoviridae/immunology* ; Mycobacterium tuberculosis/genetics* ; Mice ; Female ; Phosphoric Diester Hydrolases/genetics* ; Tuberculosis Vaccines/administration & dosage* ; Tuberculosis/prevention & control* ; Mice, Inbred BALB C ; Cytokines ; Lung/microbiology* ; Immunization ; Bronchoalveolar Lavage Fluid/immunology* ; Immunity, Mucosal

Objective To investigate the effects and molecular mechanism of Homer protein homolog 1a (Homer 1a) overexpression on nerve injury in mice with traumatic brain injury (TBI). Methods Sixty male C57BL/6 mice were randomly divided into five groups: sham group, TBI group, empty lentivirus (Lv-NC) group, Homer 1a overexpression lentivirus (Lv-Homer 1a) group and Lv-Homer 1a + 740 Y-P group, with 12 mice in each group. The lentivirus was orthotopic injected into the cerebral cortex of mice 5 d before modeling, while 740 Y-P was injected intraperitoneally 1 d before modeling. The TBI model was established using the free-fall impact method, and the modified neurological severity scores (mNSS) of the mice was assessed 72 h post-surgery. The water content of brain tissue was quantified, and the histopathological damage and neuronal loss in brain tissue were assessed using HE staining and Nissl staining respectively. The formation of autophagosomes in brain tissue was observed by transmission electron microscopy. The protein expression levels of Homer 1a, microtubule-associated protein 1 light chain 3B (LC3B), Beclin 1, phosphatidylinositol 3-kinase (PI3K), phosphorylation PI3K(p-PI3K), protein kinase B (AKT), p-AKT, mammalian target of rapamycin (mTOR), and p-mTOR in brain tissue were detected by Western blot analysis. Results Compared to the sham group, the mice in the TBI group exhibited a significant increase in mNSS and cerebral water content. Moreover, severe brain tissue pathological damage was observed, accompanied by a substantial loss of neurons and an increase in autophagosome formation. The protein expressions of Homer 1a and Beclin 1, as well as the protein ratio of LC3B-II/LC3B-I, in brain tissues were significantly elevated, while the protein ratios of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR were significantly reduced. Compared to the TBI group, the Lv-Homer 1a group exhibited reduced mNSS and brain water content. Additionally, there was an improvement in pathological brain tissue damage and neuron loss. Furthermore, there was an increase in autophagosome formation and expression of autophagy-related proteins, while the protein ratios of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR were decreased. Compared to the Lv-Homer 1a group, the nerve injury in the Lv-Homer 1a+740 Y-P group was exacerbated, accompanied by a reduction in autophagosome formation and expression of autophagy-related proteins, while the PI3K/AKT/mTOR signaling pathway was activated. Conclusion Overexpression of Homer 1a effectively mitigates neurological damage in TBI mice, potentially through modulation of autophagy mediated by the PI3K/AKT/mTOR signaling pathway.
Animals ; TOR Serine-Threonine Kinases/genetics* ; Autophagy ; Brain Injuries, Traumatic/pathology* ; Male ; Proto-Oncogene Proteins c-akt/genetics* ; Phosphatidylinositol 3-Kinases/genetics* ; Homer Scaffolding Proteins/metabolism* ; Mice, Inbred C57BL ; Signal Transduction ; Mice