The goal of this study was to investigate the regulatory effect of angiotensin converting enzyme 2 (ACE2) on cellular inflammation caused by avian infectious bronchitis virus (IBV) and the underlying mechanism of such effect. Vero and DF-1 cells were used as test target to be exposed to recombinant IBV virus (IBV-3ab-Luc). Four different groups were tested: the control group, the infection group[IBV-3ab-Luc, MOI (multiplicity of infection)=1], the ACE2 overexpression group[IBV-3ab Luc+pcDNA3.1(+)-ACE2], and the ACE2-depleted group (IBV-3ab-Luc+siRNA-ACE2). After the cells in the infection group started to show cytopathic indicators, the overall protein and RNA in cell of each group were extracted. real-time quantitative polymerase chain reaction (RT-qPCR) was used to determine the mRNA expression level of the IBV nucleoprotein (IBV-N), glycoprotein 130 (gp130) and cellular interleukin-6 (IL-6). Enzyme linked immunosorbent assay (ELISA) was used to determine the level of IL-6 in cell supernatant. Western blotting was performed to determine the level of ACE2 phosphorylation of janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3). We found that ACE2 was successfully overexpressed and depleted in both Vero and DF-1 cells. Secondly, cytopathic indicators were observed in infected Vero cells including rounding, detaching, clumping, and formation of syncytia. These indicators were alleviated in ACE2 overexpression group but exacerbated when ACE2 was depleted. Thirdly, in the infection group, capering with the control group, the expression level of IBV-N, gp130, IL-6 mRNA and increased significantly (P < 0.05), the IL-6 level was significant or extremely significant elevated in cell supernatant (P < 0.05 or P < 0.01); the expression of ACE2 decreased significantly (P < 0.05); protein phosphorylation level of JAK2 and STAT3 increased significantly (P < 0.05). Fourthly, comparing with the infected group, the level of IBV-N mRNA expression in the ACE2 overexpression group had no notable change (P > 0.05), but the expression of gp130 mRNA, IL-6 level and expression of mRNA were elevated (P < 0.05) and the protein phosphorylation level of JAK2 and STAT3 decreased significantly (P < 0.05). In the ACE2-depleted group, there was no notable change in IBV-N (P > 0.05), but the IL-6 level and expression of mRNA increased significantly (P < 0.05) and the phosphorylation level of JAK2 and STAT3 protein decreased slightly (P > 0.05). The results demonstrated for the first time that ACE2 did not affect the replication of IBV in DF-1 cell, but it did contribute to the prevention of the activation of the IL-6/JAK2/STAT3 signaling pathway, resulting in an alleviation of IBV-induced cellular inflammation in Vero and DF-1 cells.
Animals ; Chlorocebus aethiops ; Humans ; Interleukin-6/genetics* ; Janus Kinase 2/pharmacology* ; Infectious bronchitis virus/metabolism* ; STAT3 Transcription Factor/metabolism* ; Angiotensin-Converting Enzyme 2/pharmacology* ; Cytokine Receptor gp130/metabolism* ; Vero Cells ; Signal Transduction ; Inflammation ; RNA, Messenger

The extracellular domain (p75ECD) of p75 neurotrophin receptor (p75NTR) antagonizes Aβ neurotoxicity and promotes Aβ clearance in Alzheimer's disease (AD). The impaired shedding of p75ECD is a key pathological process in AD, but its regulatory mechanism is largely unknown. This study was designed to investigate the presence and alterations of naturally-occurring autoantibodies against p75ECD (p75ECD-NAbs) in AD patients and their effects on AD pathology. We found that the cerebrospinal fluid (CSF) level of p75ECD-NAbs was increased in AD, and negatively associated with the CSF levels of p75ECD. Transgenic AD mice actively immunized with p75ECD showed a lower level of p75ECD and more severe AD pathology in the brain, as well as worse cognitive functions than the control groups, which were immunized with Re-p75ECD (the reverse sequence of p75ECD) and phosphate-buffered saline, respectively. These findings demonstrate the impact of p75ECD-NAbs on p75NTR/p75ECD imbalance, providing a novel insight into the role of autoimmunity and p75NTR in AD.
Mice ; Animals ; Alzheimer Disease/pathology* ; Receptor, Nerve Growth Factor ; Amyloid beta-Peptides ; Autoantibodies ; Mice, Transgenic

Humans ; Nerve Tissue Proteins ; Epithelial-Mesenchymal Transition/genetics* ; Constriction, Pathologic ; Receptors, Immunologic ; Epithelial Cells/metabolism* ; Smad3 Protein/metabolism* ; Transforming Growth Factor beta1/metabolism*

The neurotrophin-tyrosine receptor kinase B (TrkB) signaling pathway plays an important role in regulating the balance of excitation and inhibition in the primary visual cortex (V1). Previous studies have revealed its mechanism of regulating the level of cortical excitability by increasing the efficiency of excitatory transmission, but it has not been elucidated how TrkB receptors regulate the balance of excitation and inhibition through the inhibitory system, which in turn affects visual cortex function. Therefore, the objective of this study was to investigate how the TrkB signaling pathway specifically regulates the most important inhibitory neuron-PV neurons affects the visual cortex function of mice. The expression of TrkB receptor on PV neurons in the V1 region was specifically reduced by the virus, the functional changes of inhibitory and excitatory neurons in the primary visual cortex were recorded by multi-channel electrophysiological in vivo. The orientation discrimination ability of mice was tested by behavioral experiments, and altered orientation discrimination ability of mice was tested by behavioral experiments. The results showed that reduced expression of TrkB receptors on PV inhibitory neurons in primary visual cortex significantly increased the response intensity of excitatory neurons, reduced the orientation discrimination ability of inhibitory and excitatory neurons, and increased the signal-to-noise ratio, but the orientation discrimination ability at the individual level in mice showed a decrease. These results suggest that the TrkB signaling pathway does not modulate the function of PV neurons solely by increasing excitatory transmission targeting PV neurons, and its effect on neuronal signal-to-noise ratio is not due to enhancement of the inhibitory system.
Mice ; Animals ; Receptor, trkB/metabolism* ; Neurons/metabolism* ; Signal Transduction

Objective: To investigate the clinicopathological, immunohistochemical and molecular genetic characteristics of gastric carcinoma with NTRK-rearrangement/amplification. Methods: The clinicopathological data of gastric carcinoma cases with NTRK-rearrangement/amplification diagnosed from January 2011 to September 2020 at the Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, China, were collected. The clinicopathological, immunophenotypic and molecular pathological features were analyzed. The relevant literature was reviewed. Results: There were 4 cases of gastric carcinoma with NTRK-rearrangement/amplification. All 4 patients were male, aged 57-67 years (average, 63 years). Tumor sizes ranged from 3.5 to 5.2 cm (average, 4.8 cm). All tumors were in the antrum. All 4 patients underwent radical gastrectomy and were followed up after the surgery. Morphologically, all tumors showed histological features with enteroblastic-differentiated gastric carcinoma. Tumor cells showed predominantly tubular/papillary architecture, with conspicuous vesicular nuclei and pale staining or transparent cytoplasm. Immunohistochemistry showed pan-TRK expression in all cases, with various degrees of positivity in the cytoplasm. All cases were subject to NTRK1/2/3 detection using fluorescence in situ hybridization. There were NTRK translocations in 2 cases and NTRK amplifications in 2 cases. These cases were further verified by RNAseq next generation sequencing which confirmed that NTRK1 gene translocation (TPM3-NTRK1) and NTRK2 gene translocation (NTRK2-SMCHD1) occurred in two cases, respectively. Conclusions: NTRK mutation occurs less frequently in gastric cancer. In this study, the cases mainly occur in the antrum. The morphology has the characteristics of enteroblastic differentiation. The tumors have unique histological, immunophenotypic and molecular characteristics, which require much attention from pathologists to effectively guide clinicians to choose the best treatment.
Humans ; Male ; Female ; Receptor, trkA/genetics* ; Stomach Neoplasms/surgery* ; In Situ Hybridization, Fluorescence ; Biomarkers, Tumor/genetics* ; Translocation, Genetic ; Carcinoma ; Oncogene Proteins, Fusion/genetics* ; Chromosomal Proteins, Non-Histone/genetics*

Humans ; Clinical Relevance ; Receptor, trkA/genetics* ; Neoplasms ; Digestive System Neoplasms/genetics* ; Oncogene Proteins, Fusion/genetics* ; Gene Fusion

Humans ; Receptor, trkA/genetics* ; Neoplasms/genetics* ; Biomarkers, Tumor ; Gene Rearrangement ; Oncogene Proteins, Fusion/genetics*

Objective: To investigate the clinicopathological features and differential diagnosis of NTRK3 gene rearrangement thyroid papillary carcinoma (PTC). Methods: The PTC cases without BRAF V600E mutation were collected at Fujian Provincial Hospital South Branch from January 2015 to January 2020. The cases of NTRK3 gene rearrangement PTC were examined using immunohistochemistry and fluorescence in situ hybridization (FISH). The clinical data, histopathological characteristics, immunohistochemical features and molecular pathological changes were retrospectively analyzed. Data from the TCGA PTC dataset and the literature were also studied. Results: A total of 3 PTC cases harboring NTRK3 gene rearrangement were confirmed. All the patients were female, aged from 26,49,34 years. Histologically, two of them demonstrated a multinodular growth pattern. Only one case showed prominent follicular growth pattern; the other two tumors showed a mixture of follicular, papillary and solid growth patterns. All tumors showed a typical PTC nuclear manifestation, with some nuclear pleomorphism, vacuolated foci and oncocytic features. The characteristic formation of glomeruloid follicular foci was present in two cases which also showed psammoma bodies, and tumoral capsular or angiolymphatic invasion. The background thyroid parenchyma showed chronic lymphocytic thyroiditis. Mitotic rates were low, and no cases had any tumor necrosis. The pan-TRK and TTF1 testing was both positive in 3 cases, while S-100 and mammaglobin were both negative in them. FISH studies confirmed the NTRK3 gene rearrangement in all 3 cases. Studies on the TCGA datasets and literature revealed similar findings. Conclusions: NTRK3 gene rearrangement PTC is rare. It may be easily misdiagnosed due to the lack of histological and clinicopathological characteristics. Molecular studies such as pan-TRK immunostaining, FISH and even next-generation sequencing are needed to confirm the diagnosis. Immunohistochemistry of pan-TRK performed in the PTC cases without BRAF V600E mutation can be used as a good rapid-screening tool. With the emergence of pan-cancer tyrosine receptor kinase inhibitors, proper diagnosis of these tumors can help determine appropriate treatments and improve their outcomes.
Biomarkers, Tumor ; Female ; Gene Rearrangement ; Humans ; In Situ Hybridization, Fluorescence ; Mutation ; Proto-Oncogene Proteins B-raf/genetics* ; Receptor, trkC ; Retrospective Studies ; Thyroid Cancer, Papillary/genetics* ; Thyroid Neoplasms/genetics*

OBJECTIVE: To investigate the inhibitory effect of ANA-12 that blocks brain-derived neurotrophic factor (BDNF)/ tropomyosin receptor kinase B (TrkB) signaling on inflammatory pain in rats and explore the underlying mechanism. METHODS: Forty-two adult SD rats were randomized into BDNF-induced acute pain group (n=24) and CFA-induced chronic pain group. The former group were randomly divided into 4 subgroups, including a control group, ANA-12 treatment group, BDNF treatment group, and BDNF+ANA-12 treatment group; the latter group were subgrouped into control group, CFA treatment group (CFA) and CFA + ANA-12 treatment group. The effects of ANA-12 treatment on pain behaviors of the rats with BDNF-induced acute pain and CFA-induced chronic inflammatory pain were observed. Western blotting was used to examine TrkB signaling and expressions of microglia marker protein Iba1 and TNF-α in the spinal cord of the rats. RESULTS: BDNF injection into the subarachnoid space significantly increased the number of spontaneous paw withdrawal of the rats (P < 0.05), which was obviously reduced by ANA-12 treatment (P < 0.05). The rats with intraplantar injection of CFA, showed significantly increased ipsilateral mechanical stimulation sensitivity (P < 0.05), and ANA-12 treatment obviously increased the ipsilateral foot withdrawal threshold (P < 0.05). Treatment with either BDNF or CFA significantly increased the phosphorylation level of TrkB (Y705) in the spinal cord of the rats (P < 0.05), which was significantly lowered by ANA-12 treatment (P < 0.05). Treatment with BDNF and CFA both significantly up-regulated the expressions of Iba1 and TNF-α in the spinal cord (P < 0.05), but ANA-12 significantly reduced their expression levels (P < 0.05). CONCLUSION ANA-12 can reduce spinal cord inflammation and relieve acute and chronic pain in rats by targeted blocking of BDNF/TrkB signaling.
Animals ; Brain-Derived Neurotrophic Factor/metabolism* ; Chronic Pain/drug therapy* ; Inflammation ; Rats ; Rats, Sprague-Dawley ; Receptor, trkB/metabolism*

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Zusanli" (ST 36) on duodenal mast cells, nerve growth factor (NGF) and neurotrophic tyrosine kinase receptor type 1 (NTRK1), and to explore the mechanism of electroacupuncture at Zusanli (ST 36) on functional dyspepsia (FD). METHODS: Sixty SPF-grade 10-day-old SD rats were randomly divided into a normal group, a model group, a ketotifen group and an EA group, 15 rats in each group. The FD model was prepared by iodoacetamide combined with rat tail clamping method in the model group, the ketotifen group and the EA group. The rats in the ketotifen group were injected intraperitoneally with ketotifen (1 mg•kg^-1•d^-1) for 7 days; the rats in the EA group were treated with EA at bilateral "Zusanli" (ST 36), with disperse-dense wave, frequency of 2 Hz/50 Hz and intensity of 0.5 mA, 20 min each time, once a day for 14 days. The gastric emptying rate and small intestinal propulsion rate in each group were observed; the morphology of duodenal mucosa was observed by HE staining; the toluidine blue staining was used to observe the number and degranulation of mast cells in duodenal mucosa; the protein and mRNA expressions of NGF, NTRK1 in duodenum were detected by Western blot and real-time PCR; the level of interleukin-1β (IL-1β) in duodenum was measured by ELISA. RESULTS: Compared with the normal group, the gastric emptying rate and small intestinal propulsion rate in the model group were decreased (P<0.01); compared with the model group, the gastric emptying rate and small intestinal propulsion rate in the ketotifen group and the EA group were increased (P<0.01); the small intestinal propulsion rate in the EA group was higher than that in the ketotifen group (P<0.01). In the model group, local defects in duodenal mucosa were observed with a small amount of inflammatory cell infiltration; no obvious abnormality was found in duodenal mucosa of the other groups. Compared with the normal group, the mast cells of duodenal mucosa in the model group were increased significantly with significant degranulation; compared with the model group, the mast cells of duodenal mucosa in the ketotifen group and the EA group were decreased significantly, and the degranulation was not obvious. Compared with the normal group, the protein and mRNA expressions of NGF, NTRK1 as well as the level of IL-1β in duodenum in the model group were increased (P<0.01); compared with the model group, the protein and mRNA expressions of NGF, NTRK1 as well as the levels of IL-1β in duodenum in the ketotifen group and the EA group were decreased (P<0.01, P<0.05); compared with the ketotifen group, the mRNA expression of NGF, as well as the protein and mRNA expressions of NTRK1 in duodenum in the EA group were decreased (P<0.05, P<0.01). CONCLUSION EA at "Zusanli" (ST 36) could inhibit the activation of duodenal mast cells and regulate the expressions of NGF and its receptor to improve the low-grade inflammatory response of duodenum, resulting in treatment effect on FD.
Acupuncture Points ; Animals ; Duodenum/metabolism* ; Dyspepsia/therapy* ; Electroacupuncture ; Ketotifen ; Mast Cells/metabolism* ; Nerve Growth Factor/metabolism* ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley ; Receptor, trkA/genetics*