Objective To investigate the effect of the small molecule inhibitor C42 of kallikrein-related peptidase 7(KLK7)on ovarian cancer with elevated expression of KLK7 and evaluate the feasibility of C42 as a new therapeutic strategy for ovarian cancer.Methods The CCK-8 assay,flow cytometry,cell scratch assay,Transwell assay,and Western blotting were employed to assess the effects of C42 on the proliferation,migration,and invasion of the ovarian cancer cell line SKOV3,which was characterized by high KLK7 expression.Additionally,a subcutaneous xenograft model of ovarian cancer was established with SKOV3 cells in nude mice to evaluate the effects of C42 on the tumor growth and metastasis.The expression levels of proteins associated with tumor metastasis and invasion in the tumor tissue were examined by immunohistochemical techniques.Results The cellular experiment showed that C42 suppressed the proliferation,migration,and invasion(all P<0.001)of SKOV3 cells,compared with the control group.The animal experiment showed that compared with the control group,the 10.2 mg/kg C42 group exhibited a decreased tumor weight(P=0.009) and attenuated liver metastases.Immunohistochemical staining revealed that the 10.2 mg/kg C42 group demonstrated down-regulated expression of the tumor proliferation marker Ki-67(P=0.002)and the tumor metastasis and invasion-associated proteins such as matrix metalloproteinase-9(P=0.027)and Vimentin(P=0.039).Conclusion The small molecule inhibitor C42 of KLK7 effectively suppresses the proliferation,migration,and invasion of ovarian cancer SKOV3 cells.
Female ; Humans ; Ovarian Neoplasms/drug therapy* ; Kallikreins/antagonists & inhibitors* ; Animals ; Mice, Nude ; Cell Line, Tumor ; Cell Proliferation/drug effects* ; Mice ; Cell Movement/drug effects* ; Xenograft Model Antitumor Assays ; Mice, Inbred BALB C

PURPOSE: To investigate the pathological changes of the synovium in mice with post-traumatic osteoarthritis (PTOA) treated with 4-octyl itaconate (4-OI) and evaluate the therapeutic effects of 4-OI. METHODS: In the phenotypic validation experiment, the mice were randomly divided into 3 groups: wild-type (WT) group, sham group, and destabilization of the medial meniscus (DMM) group. Through MRI, micro-CT, and histological analysis, it was determined that the DMM surgery induced a mouse PTOA model with significant signs of synovitis. At 12 weeks post-DMM surgery, synovial tissues from the DMM group and WT group mice were collected for ribonucleic acid sequencing analysis. In the 4-OI treatment experiment, mice were randomly divided into the sham group, DMM group, DMM + 4-OI (50 mg/kg) group, and DMM + 4-OI (100 mg/kg) group. Von Frey tests and open field tests were conducted at intervals during the 12 weeks following the DMM surgery. After 12 weeks of surgery, the efficacy of 4-OI treatment on PTOA in mice was evaluated using MRI, micro-CT, histological analysis, and quantitative real-time polymerase chain reaction. Finally, we utilized network pharmacology analysis to predict the mechanism of 4-OI in treating PTOA synovitis and conducted preliminary validation. Statistical analysis was performed using one-way ANOVA and the Kruskal-Wallis test. Difference was considered statistically significant at p < 0.05. RESULTS: The DMM surgery effectively induced a PTOA mouse model, which displayed significant symptoms of synovitis. These symptoms included a notable increase in both the number of calcified tissues and osteophytes (p < 0.001), an enlargement of the calcified meniscus and synovial tissue volume (p < 0.001), and thickening of the synovial lining layer attributable to M1 macrophage accumulation (p = 0.035). Additionally, we observed elevated histological scores for synovitis (p < 0.001). Treatment with 4-OI inhibited the thickening of M1 macrophages in the synovial lining layer of PTOA mice (p < 0.001) and reduced fibrosis in the synovial stroma (p = 0.004). Furthermore, it reduced the histological scores of knee synovitis in PTOA mice (p = 0.006) and improved the inflammatory microenvironment associated with synovitis. Consequently, this treatment alleviated pain in PTOA mice (p < 0.001) and reduced spontaneous activity (p = 0.003). Bioinformatics and network pharmacology analyses indicated that 4-OI may exert its therapeutic effects by inhibiting the differentiation of synovial Th17 cells. Specifically, compared to the lipopolysaccharide stimulation group, 4-OI reduced the levels of positive regulatory factors of Th17 cell differentiation (IL-1: p < 0.001, IL-6: p < 0.001), key effector molecules (IL-17A: p < 0.001, IL-17F: p = 0.004), and downstream effector molecules in the IL-17 signaling pathway (CCL2: p < 0.001, MMP13: p < 0.001). CONCLUSION 4-OI is effective in inhibiting synovitis in PTOA, thereby alleviating the associated painful symptoms.
Animals ; Synovitis/etiology* ; Mice ; Osteoarthritis/etiology* ; Disease Models, Animal ; Male ; Succinates/pharmacology* ; Mice, Inbred C57BL ; X-Ray Microtomography

Prostate cancer is the second most common malignancy and the sixth leading cause of cancer-related death in men worldwide. Radical prostatectomy (RP) is the standard treatment for localized prostate cancer, but the procedure often results in postoperative erectile dysfunction (ED). The poor efficacy of phosphodiesterase 5 inhibitors after surgery highlights the need to develop new therapies to enhance cavernous nerve regeneration and improve the erectile function of these patients. In the present study, we aimed to examine the potential of heparin-binding epidermal growth factor-like growth factor (HB-EGF) in preserving erectile function in cavernous nerve injury (CNI) mice. We found that HB-EGF expression was reduced significantly on the 1 st day after CNI in penile tissue. Ex vivo and in vitro studies showed that HB-EGF promotes major pelvic ganglion neurite sprouting and neuro-2a (N2a) cell migration. In vivo studies showed that exogenous HB-EGF treatment significantly restored the erectile function of CNI mice to 86.9% of sham levels. Immunofluorescence staining showed that mural and neuronal cells were preserved by inducing cell proliferation and reducing apoptosis and reactive oxygen species production. Western blot analysis showed that HB-EGF upregulated protein kinase B and extracellular signal-regulated kinase activation and neurotrophic factor expression. Overall, HB-EGF is a major promising therapeutic agent for treating ED in postoperative RP.
Animals ; Male ; Heparin-binding EGF-like Growth Factor/therapeutic use* ; Erectile Dysfunction/etiology* ; Mice ; Penis/drug effects* ; Nerve Regeneration/drug effects* ; Penile Erection/drug effects* ; Peripheral Nerve Injuries/drug therapy* ; Cell Proliferation/drug effects* ; Apoptosis/drug effects* ; Cell Movement/drug effects* ; Prostatectomy/adverse effects* ; Mice, Inbred C57BL ; Reactive Oxygen Species/metabolism*

OBJECTIVES: To investigate the therapeutic effects and mechanisms of 2,6-dimethoxy-1,4-benzoquinone (2,6-DMBQ) in a mouse model of asthma. METHODS: SPF-grade BALB/c mice were randomly divided into 7 groups (n=8 each group): normal control group, ovalbumin (OVA) group, dimethyl sulfoxide+corn oil group, budesonide (BUD) group, and low, medium, and high dose 2,6-DMBQ groups. An asthma mouse model was established by OVA induction, followed by corresponding drug interventions. Non-invasive lung function tests were performed to measure airway hyperresponsiveness, and enzyme-linked immunosorbent assay was used to determine levels of interleukin (IL)-17, IL-10, and serum immunoglobulin E in bronchoalveolar lavage fluid. A cell counter was employed to detect eosinophil counts in bronchoalveolar lavage fluid, while hematoxylin-eosin staining and periodic acid-Schiff staining were used to assess lung tissue pathological changes. Western blot was conducted to examine the expression of proteins related to the mammalian target of rapamycin pathway (p-AKT/AKT and p-p70S6K/p70S6K), and a fully automated biochemical analyzer was used to evaluate liver and kidney functions. RESULTS: Compared with the normal control group, the OVA group showed increased enhanced pause values, inflammation scores from hematoxylin-eosin staining, positive area from periodic acid-Schiff staining, percentage of eosinophils, IL-17/IL-10 ratio, serum immunoglobulin E levels, and relative expression levels of p-AKT/AKT and p-p70S6K/p70S6K (P<0.05). The BUD group and the medium and high dose 2,6-DMBQ groups exhibited decreased values for these indicators compared to the OVA group (P<0.05). CONCLUSIONS 2,6-DMBQ can inhibit the mTOR pathway to alleviate airway inflammation in asthmatic mice, possibly by mitigating the imbalance between Th17 and regulatory T cells.
Animals ; Asthma/pathology* ; Mice, Inbred BALB C ; Signal Transduction/drug effects* ; Mice ; TOR Serine-Threonine Kinases/physiology* ; Female ; Benzoquinones/pharmacology* ; Immunoglobulin E/blood* ; Interleukin-10/analysis* ; Interleukin-17/analysis* ; Bronchoalveolar Lavage Fluid ; Lung/pathology*

OBJECTIVES: To investigate the role and mechanism of Brahma-related gene 1 (Brg1) in regulating the Wnt/β-catenin signaling pathway in a bronchopulmonary dysplasia (BPD) model. METHODS: Wild-type C57BL/6 and Brg1^f1/f1 mice were randomly divided into four groups: wild-type control, wild-type BPD, Brg1^f1/f1 control, and Brg1^f1/f1 BPD (n=5 each). Immortalized mouse pulmonary alveolar type 2 cells (imPAC2) were cultured, and Brg1 gene was knocked down using lentivirus transfection technology. Cells were divided into three groups: control, empty vector, and Brg1 knockdown. Hematoxylin and eosin staining and immunofluorescence were used to detect pathological changes in mouse lung tissue. Western blot and real-time fluorescent quantitative PCR were used to measure Brg1 protein and mRNA expression levels in mouse lung tissue. Western blot and immunofluorescence were used to detect the expression of homeodomain-containing protein homeobox (HOPX), surfactant protein C (SPC), and Wnt/β-catenin signaling pathway proteins in mouse lung tissue and imPAC2 cells. The CCK8 assay was used to assess the proliferation of imPAC2 cells, and co-immunoprecipitation was performed to verify the interaction between Brg1 and β-catenin proteins in imPAC2 cells. RESULTS: Compared to the Brg1^f1/f1 control group and wild-type BPD group, the Brg1^f1/f1 BPD group showed increased alveolar diameter and SPC protein expression, and decreased relative density of pulmonary vasculature and HOPX protein expression (P<0.05). Compared to the control group, the Brg1 knockdown group showed increased cell proliferation ability, protein expression levels of SPC, Wnt5a and β-catenin, and β-catenin protein fluorescence intensity, along with decreased HOPX protein expression (P<0.05). An interaction between Brg1 and β-catenin proteins was confirmed. CONCLUSIONS The Brg1 gene may promote the proliferation of alveolar type 2 epithelial cells by regulating the Wnt/β-catenin signaling pathway, thus influencing the occurrence and development of BPD.
Animals ; DNA Helicases/genetics* ; Transcription Factors/genetics* ; Wnt Signaling Pathway/physiology* ; Nuclear Proteins/genetics* ; Mice ; Bronchopulmonary Dysplasia/etiology* ; Mice, Inbred C57BL ; beta Catenin/physiology* ; Disease Models, Animal ; Cell Proliferation ; Lung/pathology* ; Male

OBJECTIVES: To investigate the role and mechanism of copper overload-mediated endoplasmic reticulum stress (ERS) in vascular endothelial injury in Kawasaki disease (KD). METHODS: Four-week-old male C57BL/6 mice were randomly divided into four groups: control, KD, KD plus copper chelator tetrathiomolybdate (TTM), and KD plus ERS inhibitor AMG PERK 44 (AMG) (n=20 per group). A KD mouse model was established using Candida albicans extract. Human umbilical vein endothelial cells (HUVECs) were divided into control (intervention with healthy children's serum), KD (intervention with KD patients' serum), and KD+TTM (intervention with KD patients' serum plus 20 µmol/L TTM). Copper deposition in mouse heart tissue was assessed using rubeanic acid staining. Vascular pathological changes were observed using hematoxylin-eosin staining and measurement of abdominal aortic diameter and area. ERS activation was detected by transmission electron microscopy and immunofluorescence. HUVEC viability, apoptosis, and functional changes were evaluated using CCK8, flow cytometry, cell scratch assay, and angiogenesis experiments. ERS marker protein expression levels were measured by Western blot. RESULTS: Compared to the KD group, the KD+TTM and KD+AMG groups showed reduced copper deposition in the vascular wall, decreased swelling of coronary endothelial cells and endoplasmic reticulum, reduced inflammatory cell infiltration, and less abdominal aortic lesion expansion. The abdominal aortic diameter and area, and the fluorescence intensity of ERS marker proteins (GRP78 and CHOP) were significantly lower (P<0.05). Compared to the KD group, the KD+TTM group exhibited increased cell viability, tube number, and scratch healing rate, along with decreased apoptosis rate and expression of ERS marker proteins (GRP78, CHOP, ATF6, and p-PERK) (P<0.05). CONCLUSIONS Copper overload aggravates vascular endothelial injury in KD by activating the ERS pathway. TTM can exert protective effects on the endothelium by regulating copper metabolism and inhibiting the ERS pathway.
Endoplasmic Reticulum Stress ; Copper/toxicity* ; Male ; Mucocutaneous Lymph Node Syndrome/metabolism* ; Animals ; Humans ; Endoplasmic Reticulum Chaperone BiP ; Mice, Inbred C57BL ; Mice ; Human Umbilical Vein Endothelial Cells ; Apoptosis ; Endothelium, Vascular/injuries*

OBJECTIVES: To investigate the protective effects and underlying mechanisms of Gynostemma pentaphyllum (GP)ethanol extract on motor dysfunction in a mouse model of Parkinson's disease (PD). METHODS: Eighty C57BL/6 male mice were randomly divided into five groups: control group, model group, levodopa group (positive control group), low-dose GP group, and high-dose GP group, with 16 mice per group. The PD model was induced by injection of 6-hydroxydopamine into the substantia nigra pars reticulata of the mice. Two weeks after 6-hydroxydopamine, positive control group received intraperitoneal injection of levodopa 10 mg·kg^－1·d^－1, while low-dose GP and high-dose GP groups received GP extract 100 or 200 mg·kg^－1·d^－1 orally for three weeks. After a 3-week-treatment, the effects of GP on motor dysfunction in 6-hydroxydopamine-induced PD were assessed using open field and CatWalk gait tests, while the effects on muscle strength were evaluated by forelimb grip strength. Immunofluorescence staining was used to detect the number of tyrosine hydroxylase (TH) positive neurons. The levels of dopamine and serotonin in the midbrain were determined by enzyme-linked immunosorbent assay. In addition, Western blotting was performed to detect the expression of mitogen-activated protein kinase (MAPK) family proteins such as p-extracellular signal-regulated kinase (ERK)1/2, p-p38 and p-c-Jun N-terminal kinase (JNK)1/2, and mitochondrial apoptosis pathway proteins such as B-cell lymphoma (Bcl)-2, Bcl-2 associated X protein (Bax), and cleaved-cysteine aspartic acid specific protease (caspase)-3. RESULTS: Behavioral experiments showed that GP significantly improved the spontaneous activity and motor coordination of PD mice (P<0.05). The forelimb grip strength was also increased by GP treatment (P<0.05), compared to the PD model group. In addition, compared with the model group, the number of TH-positive neurons in substantia nigra pars reticulata region, the levels of dopamine and serotonin in midbrain and the expression of p-ERK1/2 were significantly increased by GP treatment (all P<0.05), whereas the expression of p-p38 and p-JNK1/2, the ratio of Bax/Bcl-2 and cleaved-caspase-3/caspase-3 were significantly decreased (all P<0.05). CONCLUSIONS The results indicate that GP might increase dopamine and serotonin levels in the midbrain and promote the survival of dopaminergic neurons in substantia nigra pars reticulata by regulating the expression of phosphorylation of MAPK family proteins and the expression of mitochondrial apoptosis-related proteins, thereby ameliorating motor deficits in PD mice.
Animals ; Mice ; Male ; Gynostemma/chemistry* ; Mice, Inbred C57BL ; Apoptosis/drug effects* ; Plant Extracts/therapeutic use* ; Parkinson Disease/metabolism* ; Disease Models, Animal ; Neurons/pathology*

OBJECTIVES: To explore the protective effect of vitexin-4 ″-O-glucoside (VOG) against acetaminophen-induced acute liver injury in mice and its underlying mechanism. METHODS: C57BL/6 mice were randomly divided into 4 groups: normal control group, model control group, low-dose group of VOG (30 mg/kg), and high-dose group of VOG (60 mg/kg). Acute liver injury was induced by intraperitoneal injection of acetaminophen (500 mg/kg). VOG was administrated by gavage 2 h before acetaminophen treatment in VOG groups. The protective effect of VOG against acute liver injury was evaluated by detecting alanine transaminase (ALT), aspartate transaminase (AST) levels and hematoxylin and eosin staining. The malondialdehyde (MDA) content, superoxide dismutase (SOD) and catalase (CAT) activity in liver were detected to evaluate the hepatic oxidative stress. The expression levels of tumor necrosis factor (TNF)-α, Il-1β, and Il-6 in liver were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The expression levels of phosphorylated c-jun N-terminal kinase (JNK)/JNK, phosphorylated p38/p38, inositol-requiring enzyme 1 alpha (IRE-1α), X-box binding protein 1s (XBP1s), and glucose-regulated protein 78 (GRP78) in liver were detected by Western blotting. An endoplasmic reticulum stress model was established in AML-12 cells using tunicamycin. Cell viability was assessed using the CCK-8 assay, and the degree of cell damage was detected by lactate dehydrogenase (LDH) assay. The gene expression levels of Ire-1α, Xbp1s, and Grp78 in the cells were detected using qRT-PCR. RESULTS: In the animal experiments, compared with the model control group, VOG significantly improved plasma ALT and AST levels, liver MDA content, as well as SOD and CAT activities. VOG also reduced the expression levels of Tnf-α, Il-1β, and Il-6 in the liver, and improved protein phosphorylation levels of JNK and p38, as well as the protein expression levels of IRE-1α, XBP1s, and GRP78. In cell experiments, VOG pretreatment enhanced cell viability, reduced LDH release and decreased the mRNA expression of Ire-1α, Xbp1s, and Grp78. CONCLUSIONS VOG can suppress inflammation and oxidative stress, and alleviate acetaminophen-induced acute liver injury in mice by suppressing endoplasmic reticulum stress and modulating the MAPK signaling pathway.
Animals ; Endoplasmic Reticulum Chaperone BiP ; Mice ; Acetaminophen/adverse effects* ; Mice, Inbred C57BL ; Chemical and Drug Induced Liver Injury/prevention & control* ; Glucosides/therapeutic use* ; Oxidative Stress/drug effects* ; Male ; Apigenin/therapeutic use* ; Liver/drug effects* ; Tumor Necrosis Factor-alpha/metabolism* ; Endoplasmic Reticulum Stress/drug effects* ; X-Box Binding Protein 1 ; Endoribonucleases/metabolism* ; Interleukin-1beta/metabolism* ; Interleukin-6/metabolism* ; Protein Serine-Threonine Kinases

OBJECTIVES: To investigate the effect of a variety of kidney-tonifying Chinese medicines on thymus regeneration after acute degeneration in mice. METHODS: Forty-eight 8-week-old male BALB/c mice were randomly divided into normal control group, model control group, negative control group, positive control group, the fructus of Cnidium monnieri (L.) Cuss. group, the fructus of Psoralea corylifolia (L.) group, the fructus of Rubus chingii Hu group, and the tuber onion seed group, with 6 mice in each group. Except for the normal control group, mice in the other groups received intraperitoneal injections of rapamycin (1 mg·kg^－1·d^－1) for 5 consecutive days followed by 14 h of starvation to induce acute thymus degeneration. After successful modeling, in treatment groups ethanol extract of the fructus of Cnidium monnieri (L.) Cuss. (0.78 g·kg^－1·d^－1), fructus of Psoralea corylifolia (L.) (0.39 g·kg^－1·d^－1), fructus of Rubus chingii Hu (0.78 g·kg^－1·d^－1) or the tuber onion seed(0.39 g·kg^－1·d^－1) was intraperitoneally injected once a day for 5 days; while the negative control group was given equal volume of normal saline, and the positive control group was given metformin (300 mg·kg^－1·d^－1). The grip strength was measured with a grip tester 2 h after the last administration. The pathological changes of thymus were observed by hematoxylin and eosin (HE) staining. The structure and distribution of thymic epithelial cells were observed by multiple immunofluorescence method. The proportion of T cell subsets in thymus and peripheral blood was analyzed by flow cytometry. The level of T cell receptor excision circles (TREC) in the genomic DNA of mouse spleen mononuclear cells was detected by quantitative polymerase chain reaction (PCR) for evaluation of thymic output function. The expression of thymus aging- and function-related factors in the thymus tissue were detected by quantitative reverse transcription PCR. The expression of cyclin-dependent kinase inhibitor 1A (p21) and tumor protein 53 (p53) were verified by immunohistochemistry. RESULTS: Rapamycin induced thymic atrophy and significantly reduced limb grip strength in mice (P<0.01). Compared with the negative control group, the limb grip strength of mice in the fructus of Psoralea corylifolia (L.) group, the fructus of Rubus chingii Hu group and the tuber onion seed group was significantly enhanced (all P<0.05), and the level of TREC in spleen of the mice in each administration group was reduced (all P<0.05). Among Chinese herb medicine-treatment groups, the recovery of thymus function and tissue structure in the tuber onion seed group was most obvious. Further study showed that compared with the negative control group, the proportion of CD4 single positive cells (CD3⁺TCR-β⁺CD4⁺CD8^－) in the thymus of the tuber onion seed group was significantly increased (P<0.01), and the proportion of CD3⁺CD28⁺ T cell and CD3⁺CD8⁺CD28⁺ T cell in peripheral blood was significantly increased (all P<0.01). The mRNA levels of IL-1α, IL-6, p21 and p53 in thymocytes were decreased (all P<0.05). The results of immunohistochemistry further confirmed the decrease in p21 and p53 expression. In normal mice, tuber onion seed was observed to enhance limb grip strength (P<0.01), while suppressing thymus output and change the distribution of T cell subsets, and there was no significant effect on thymus weight and the expression of Foxn1, SIRT1, p21, CXCL2 and PTMα. CONCLUSIONS The tuber onion seed and other kidney-tonifying traditional Chinese medicines can accelerate the regeneration process of mouse thymus after acute degeneration induced by rapamycin in mice, and the tuber onion seed exhibits the most pronounced therapeutic effect.
Animals ; Mice ; Male ; Mice, Inbred BALB C ; Thymus Gland/physiology* ; Drugs, Chinese Herbal/pharmacology* ; Sirolimus/adverse effects* ; Regeneration/drug effects*

OBJECTIVES: To investigate the role of a neural pathway from oxytocin (OXT) neurons in the paraventricular hypothalamic nucleus (PVN) to γ-aminobutyric acid (GABA) neurons (GABAergic neurons) in the trigeminal nucleus caudalis (TNC) in regulating pain sensitization in a mouse model of chronic migraine and to explore the underlying mechanisms. METHODS: A chronic migraine mouse model was established by intraperitoneal injection of nitroglycerin (NTG, 1 mg/mL, 10 mg/kg) on days 1, 3, 5, 7, and 9. The study consisted of four parts: PartⅠ: 24 male wild-type C57BL/6J mice were divided into four groups (n=6 in each), receiving single or repeated injection of NTG or saline, respectively. Immunofluorescence was used to detect c-Fos and OXT expression in the PVN. Part Ⅱ: 6 male OXT-Cre transgenic C57BL/6J mice were used for anterograde monosynaptic tracing combined with RNAscope and immunofluorescence to identify neural projections from PVN OXT neurons to TNC GABAergic neurons. Part Ⅲ: 30 male OXT-Cre transgenic C57BL/6J mice were bilaterally injected Cre-dependent chemogenetic activation virus into the PVN. These mice were randomly divided into five groups, with six mice in each group. Mice in the clozapine N-oxide (CNO) group and the control group were intra-peritoneally injected with 0.1 mg/mL of CNO solution (1 mg/kg) and the same volume of isotonic normal saline, respectively. 3 hours after the injection, the brain tissues were harvest and c-Fos immunofluorescence staining was performed to verify the efficiency of chemogenetic activation virus. Mice in the model control group and the CNO activated model group were subjected to chronic migraine modeling, with bilateral TNC injection of isotonic normal saline and CNO, respectively, on day 10. The mice in the negative control group were bilaterally intra-TNC injected with isotonic normal saline. After 30 minutes, the Von-Frey filament and acetone tests were used to assess the mechanical pain threshold and cold pain response time in the periorbital region of the mice in these three groups. Part Ⅳ: 24 male OXT-Cre transgenic C57BL/6J mice were bilaterally injected with the Cre-dependent chemogenetic activation virus into the PVN. These mice were randomly divided into four groups, with six mice in each group. Mice in the model control group, the CNO activated model group and the atosiban group were subjected to chronic migraine modeling. On day 10, mice in the negative control group and the model control group were intraperitoneally injected with isotonic normal saline, while mice in the CNO activated model group and the atosiban group were intraperitoneally injected with CNO. After 15 minutes, mice in the atosiban group were bilaterally intra-TNC injected with atosiban, while mice in other three groups were bilaterally intra-TNC injected with isotonic normal saline containing 1% dimethyl sulfoxide. After 15 minutes, the Von-Frey filament and acetone tests were used to assess the mechanical pain threshold and cold pain response time in the periorbital region of the mice. The GABA content in the bilateral TNC was detected by high-performance liquid chromatography (HPLC). RESULTS: Mice with chronic migraine models exhibited reduced periorbital mechanical pain thresholds and increased periorbital cold pain reaction time, accompanied by an increase in both the number of c-Fos⁺ neurons and the percentage of c-Fos⁺ OXT neurons in the PVN (all P<0.05). The anterograde tracing virus and RNAscope combined with immunofluorescence staining showed that PVN OXT neurons projected to TNC GABAergic neurons. Immuno-fluorescence staining demonstrated that compared with the control group, the percentage of c-Fos⁺ OXT neurons in the PVN of CNO group increased (P<0.05). In bilateral intra-TNC drug administration experiments, compared with the model control group, the periorbital mechanical pain threshold increased, and the periorbital cold pain reaction time decreased in the CNO activated model group (both P<0.05). In intraperitoneal drug administration experiments, compared with the CNO activate model group, the periorbital mechanical pain threshold decreased, and the periorbital cold pain reaction time increased in the atosiban group (both P<0.05). HPLC analysis showed that, compared with the negative control group, the model control group and the atosiban group, GABA level of TNC in the CNO activated model group increased (all P<0.05). CONCLUSIONS PVN OXT neurons exert a descending facilitatory effect on GABAergic neurons in the TNC via OXT release, thereby ameliorating pain sensitization in chronic migraine.
Animals ; Paraventricular Hypothalamic Nucleus/physiopathology* ; Male ; Mice, Inbred C57BL ; Migraine Disorders/physiopathology* ; Mice ; GABAergic Neurons/physiology* ; Oxytocin/physiology* ; Disease Models, Animal ; Neurons/physiology* ; Mice, Transgenic ; Neural Pathways ; Chronic Disease