The parabrachial nucleus (PB) is composed of glutamatergic neurons at the midbrainhindbrain junction. These neurons form many subpopulations, one of which expresses Calca, which encodes the neuropeptide calcitonin gene-related peptide (CGRP). This Calca-expressing subpopulation has been implicated in a variety of homeostatic functions, but the overall distribution of Calca-expressing neurons in this region remains unclear. Also, while previous studies in rats and mice have identified output projections from CGRP-immunoreactive or Calca-expressing neurons, we lack a comprehensive understanding of their efferent projections. We began by identifying neurons with Calca mRNA and CGRP immunoreactivity in and around the PB, including populations in the locus coeruleus and motor trigeminal nucleus. Calcaexpressing neurons in the PB prominently express the mu opioid receptor (Oprm1) and are distinct from neighboring neurons that express Foxp2 and Pdyn. Next, we
IL-17 is a signature cytokine of Th17 cells implicated in the induction and progression of chronic inflammatory diseases. Several studies in C57BL/6 mice, immunized with soluble schistosome egg Ags (SEA) in complete Freund's adjuvant (CFA), and subsequently infected with Schistosoma mansoni (S. mansoni) have shown that severe hepatic granulomatous inflammation is correlated with high levels of IL-17. Here, using a Schistosoma japonicum (S. japonicum) larvae infection model in C57BL/6 mice, we analyzed the dynamic expression of IL-17 in infected livers by RT-qPCR and ELISA. Our results showed that IL-17 expression was elevated during the course of infection. The temporal expression of IL-17 and cytokines/chemokines involved in the induction and effector function of Th17 cells was paralleled with hepatic granulomatous inflammation. Treatment of S. japonicum infected mice with IL-17-neutralizing mAb resulted in significant downmodulation of granulomatous inflammation and hepatocyte necrosis. The protection was associated with lower expression of proinflammatory cytokines/chemokines, such as IL-6, IL-1β, CXCL1, and CXCL2 and a reduced number of infiltrating neutrophils. Anti-IL-17 mAb significantly ameliorated hepatic granulomatous inflammation, partly through the downregulation of proinflammatory cytokines/chemokines and recruitment of neutrophils. Our data indicate a pathogenic role of Th17/IL-17 in hepatic immunopathology in S. japonicum infected mice. Keywords: CD4+ T cells r Granulomatous inflammation r IL-17 r Schistosoma japonicum IntroductionSchistosomiasis is a serious global helminth-induced disease, which affects more than 200 million people worldwide [1]. ThereCorrespondence: Jijia Shen e-mail: shenjijia@hotmail.com are three major species that infect humans: Schistosoma japonicum (S. japonicum), Schistosoma mansoni, and Schistosoma haematobium. The common pathological changes, including those in schistosomiasis japonica [2], are granulomatous and fibrotic inflammation against parasite eggs deposited in the liver and intestines. Schistosoma japonicum is mainly distributed in Southeast Asia, is a major public health concern in China. About one million people, more than 1.7 million cattle and other mammals are currently Eur. J. Immunol. 2012Immunol. . 42: 1523Immunol. -1535 infected [3]. It has long been recognized that granuloma formation is a CD4 + T-cell-dependent, cell-mediated process. After infection, immune responses to schistosoma antigens demonstrate a marked switch from a moderate proinflammatory Th1 response to a vigorous Th2-dominated response with the beginning of oviposition around 4 weeks postinfection (p.i.) [4]. Multiple studies on the pathogenesis of granuloma formation have investigated the cytokine patterns mediated by antigen-specific T cells in mice with schistosomiasis japonica. In particular, the roles of the so-called Th1 and Th2 cytokines have been elucidated. The requirement for CD4 + T cells in granulomatous inflammation was verified in MHC class II-deficient mice, which demon...
The parabrachial nucleus (PB) is a complex structure located at the junction of the midbrain and hindbrain. Its neurons have diverse genetic profiles and influence a variety of homeostatic functions. While its cytoarchitecture and overall efferent projections are known, we lack comprehensive information on the projection patterns of specific neuronal subtypes in the PB. In this study, we compared the projection patterns of glutamatergic neurons here with a subpopulation expressing the transcription factor Foxp2 and a further subpopulation expressing the neuropeptide Pdyn. To do this, we injected an AAV into the PB region to deliver a Cre-dependent anterograde tracer (synaptophysin-mCherry) in three different strains of Cre-driver mice. We then analyzed 147 neuroanatomical regions for labeled boutons in every brain (n = 11). Overall, glutamatergic neurons in the PB region project to a wide variety of sites in the cerebral cortex, basal forebrain, bed nucleus of the stria terminalis,
Acid-sensing ion channels, a proton-gated cation channel, can be activated by low extracellular pH and involved in pathogenesis of some tumors such as glioma and breast cancer. However, the role of acid-sensing ion channels in the growth of lung cancer cell is unclear. In this study, we investigated the expression of acid-sensing ion channels in human lung cancer cell line A549 and their possible role in proliferation and migration of A549 cells. The results show that acid-sensing ion channel 1, acid-sensing ion channel 2, and acid-sensing ion channel 3 are expressed in A549 cells at the messenger RNA and protein levels, and acid-sensing ion channel-like currents were elicited by extracellular acid stimuli. Moreover, we found that acidic extracellular medium or overexpressing acid-sensing ion channel 1a promotes proliferation and migration of A549 cells. In addition psalmotoxin 1, a specific acid-sensing ion channel 1a inhibitor, or acid-sensing ion channel 1a knockdown can abolish the effect of acid stimuli on A549 cells. In addition, acid-sensing ion channels mediate increase of [Ca] induced by low extracellular pH in A549 cells. All these results indicate that acid-sensing ion channel-calcium signal mediate lung cancer cell proliferation and migration induced by extracellular acidosis, and acid-sensing ion channels may serve as a prognostic marker and a therapeutic target for lung cancer.
Diverse neurons in the parabrachial nucleus (PB) communicate with widespread brain regions. Despite evidence linking them to a variety of homeostatic functions, it remains difficult to determine which PB neurons influence which functions because their subpopulations intermingle extensively. An improved framework for identifying these intermingled subpopulations would help advance our understanding of neural circuit functions linked to this region. Here, we present the foundation of a developmental‐genetic ontology that classifies PB neurons based on their intrinsic, molecular features. By combining transcription factor labeling with Cre fate‐mapping, we find that the PB is a blend of two, developmentally distinct macropopulations of glutamatergic neurons. Neurons in the first macropopulation express Lmx1b (and, to a lesser extent, Lmx1a) and are mutually exclusive with those in a second macropopulation, which derive from precursors expressing Atoh1. This second, Atoh1‐derived macropopulation includes many Foxp2‐expressing neurons, but Foxp2 also identifies a subset of Lmx1b‐expressing neurons in the Kölliker–Fuse nucleus (KF) and a population of GABAergic neurons ventrolateral to the PB (“caudal KF”). Immediately ventral to the PB, Phox2b‐expressing glutamatergic neurons (some coexpressing Lmx1b) occupy the KF, supratrigeminal nucleus, and reticular formation. We show that this molecular framework organizes subsidiary patterns of adult gene expression (including Satb2, Calca, Grp, and Pdyn) and predicts output projections to the amygdala (Lmx1b), hypothalamus (Atoh1), and hindbrain (Phox2b/Lmx1b). Using this molecular ontology to organize, interpret, and communicate PB‐related information could accelerate the translation of experimental findings from animal models to human patients.
Accumulating evidence has identified the profibrogenic properties of IL-17A in organ fibrosis. However, the role of IL-17A signal in liver fibrosis induced by Schistosoma japonicum infection remains unclear. In this study, we investigated liver fibrosis in wild-type (WT) and IL-17RA(-/-) mice upon S. japonicum infection. Hepatic IL-17A, IL-17C, IL-17E (IL-25), IL-17F, IL-17RA, IL-17RB and IL-17RC transcript levels were determined by RT-PCR. IL-17A(+) cells were analyzed by flow cytometry and confocal microscopy among granuloma cells. Immunostaining of IL-17R was performed on liver sections. Collagen deposition was assessed by Van Gieson's staining. IL-17A, IL-17C, IL-17E, IL-17F, IL-17RA and IL-17RC mRNA levels were dramatically increased in fibrotic livers. Among granuloma cells, CD3(+) and CD3(-) lymphocytes, neutrophils and macrophages were found to express IL-17A. Compared to WT, IL-17RA(-/-) mice displayed attenuated granulomatous inflammation, liver fibrosis, improved liver function and high survival. Meanwhile, α-smooth muscle actin staining and the expression of fibrogenic genes (transforming growth factor β, IL-13 and collagen-I) as well as IL-17A-induced proinflammatory mediators (IL-1β, IL-6, tumor necrosis factor α, CXCL1 and CXCL2) and proteinases (MMP3 and TIMP1) involved in fibrosis were markedly reduced in IL-17RA(-/-) mice. In addition, Th2 cytokines IL-4 and IL-17E (IL-25) were also decreased in IL-17RA(-/-) mice. These results indicated that IL-17A signal contributes to the pathogenesis of liver fibrosis in murine schistosomiasis. This effect was induced possibly by activating hepatic stellate cells and stimulating the release of proinflammatory cytokines and chemokines. Furthermore, the Th2 response was also enhanced by IL-17A signals. Our data demonstrate that IL-17A may serve as a promising target for antifibrotic therapy.
Oxidative stress and neuroinflammation are important in the pathogenesis of ageing and age-related neurodegenerative diseases, including Alzheimer’s disease. NADPH oxidase 2 (NOX2) is a major source of reactive oxygen species (ROS) in the brain. The nucleotide-binding oligomerisation domain (NOD)-like receptor protein 1 (NLRP1) inflammasome is responsible for the formation of pro-inflammatory molecules in neurons. Whether the NOX2-NLRP1 inflammasome signalling pathway is involved in neuronal ageing and age-related damage remains to be elucidated. Ginsenoside Rg1 (Rg1) is a steroidal saponin found in ginseng. In the present study, the primary hippocampal neurons were treated with H2O2 (200 µM) and Rg1 (1, 5 and 10 µM) for 24 h to investigate the protective effects and mechanisms of Rg1 on H2O2-induced hippocampal neuron damage, which mimics age-related damage. The results showed that H2O2 treatment significantly increased ROS production and upregulated the expression of NOX2 and the NLRP1 inflammasome, and led to neuronal senescence and damage to hippocampal neurons. Rg1 decreased ROS production, reducing the expression of NOX2 and the NLRP1 inflammasome in H2O2-treated hippocampal neurons. Furthermore, Rg1 and tempol treatment significantly decreased neuronal apoptosis and the expression of β-galactosidase, and alleviated the neuronal senescence and damage induced by H2O2. The present study indicates that Rg1 may reduce NOX2-mediated ROS generation, inhibit NLRP1 inflammasome activation, and inhibit neuronal senescence and damage.
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