Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
Rodriguez, LA;Kim, SH;Page, SC;Nguyen, CV;Pattie, EA;Hallock, HL;Valerino, J;Maynard, KR;Jaffe, AE;Martinowich, K;
PMID: 36369482 | DOI: 10.1038/s41386-022-01487-y
The lateral septum (LS) is a basal forebrain GABAergic region that is implicated in social novelty. However, the neural circuits and cell signaling pathways that converge on the LS to mediate social behaviors aren't well understood. Multiple lines of evidence suggest that signaling of brain-derived neurotrophic factor (BDNF) through its receptor TrkB plays important roles in social behavior. BDNF is not locally produced in LS, but we demonstrate that nearly all LS GABAergic neurons express TrkB. Local TrkB knock-down in LS neurons decreased social novelty recognition and reduced recruitment of neural activity in LS neurons in response to social novelty. Since BDNF is not synthesized in LS, we investigated which inputs to LS could serve as potential BDNF sources for controlling social novelty recognition. We demonstrate that selectively ablating inputs to LS from the basolateral amygdala (BLA), but not from ventral CA1 (vCA1), impairs social novelty recognition. Moreover, depleting BDNF selectively in BLA-LS projection neurons phenocopied the decrease in social novelty recognition caused by either local LS TrkB knockdown or ablation of BLA-LS inputs. These data support the hypothesis that BLA-LS projection neurons serve as a critical source of BDNF for activating TrkB signaling in LS neurons to control social novelty recognition.
IL-6 expression helps distinguish Castleman\'s disease from IgG4-related disease in the lung
Kinugawa, Y;Uehara, T;Iwaya, M;Asaka, S;Kobayashi, S;Nakajima, T;Komatsu, M;Yasuo, M;Yamamoto, H;Ota, H;
PMID: 34246246 | DOI: 10.1186/s12890-021-01603-6
It is difficult to distinguish between multicentric Castleman's disease (MCD) and IgG4-related lung disease (IgG4-LD), an IgG4-related disease (IgG4-RD) in the lung.We focused on IL-6, which is elevated in MCD, to distinguish between MCD and IgG4-LD by RNAscope, a highly sensitive RNA in situ method. Six cases of MCD and four cases of IgG4-LD were selected.In all cases of MCD and IgG4-LD, 10 or more IgG4-positive cells were found in one high-power field. All MCD cases were inconsistent with the pathological IgG4-related comprehensive diagnostic criteria, but 2 of 6 cases had an IgG4/IgG ratio greater than 40%. In all IgG4-LD cases, histological features were consistent with the pathological IgG4-RD comprehensive diagnostic criteria. IL-6 expression was observed in all MCD and IgG4-LD cases except for one IgG4-LD biopsy. IL-6-expressing cells were mainly identified in the stroma. Sites of IL-6 expression were not characteristic and were sparse. IL-6 expression tended to be higher in MCD compared with IgG4-LD. A positive correlation was found between the IL-6 H-score and serum IL-6 level.Differences in IL-6 expression may help distinguish between MCD and IgG4-LD. In addition, the presence of high IL-6 levels may help elucidate the pathological mechanisms of IgG4-LD.
Otani K, Inoue D, Fujikura K, Komori T, Abe-Suzuki S, Tajiri T, Itoh T, Zen Y.
PMID: - | DOI: 10.18632/oncotarget.24068
The present study aimed to compare clinicopathologic features between idiopathic multicentric Castleman’s disease (n=22) and IgG4-related disease (n=26). Histology was analyzed using lymph node and lung biopsies. The expression of IL-6 mRNA in tissue was also examined by in situ hybridization and real-time PCR. Patients with idiopathic multicentric Castleman’s disease were significantly younger than those with IgG4-related disease (p<0.001). Splenomegaly was observed in only idiopathic multicentric Castleman’s disease (p=0.002), while pancreatitis and sialo-dacryoadenitis were restricted to IgG4-related disease (both p<0.001). Serum IgG4 concentrations were commonly elevated at >135 mg/dL in both groups (p=0.270). However, the IgG4/IgG ratio in IgG4-related disease was significantly higher than that in Castleman’s disease (p<0.001). Histologically, sheet-like plasmacytosis was highly characteristic of idiopathic multicentric Castleman’s disease (p<0.001), while plasmacytic infiltration in IgG4-related disease was always associated with intervening lymphocytes. Similar to laboratory findings, the IgG4/IgG-positive plasma cell ratio, but not the IgG4-positive cell count, was significantly higher in IgG4-related disease (p=0.002). Amyloid-like hyalinized fibrosis was found in 6/8 lung biopsies (75%) of Castleman’s disease. The over-expression of IL-6 mRNA was not confirmed in tissue samples of Castleman’s disease by either in situhybridization or quantitative real-time PCR. In conclusion, useful data for a differential diagnosis appear to be age, affected organs, the serum IgG4/IgG ratio, sheet-like plasmacytosis in biopsies, and the IgG4/IgG-positive cell ratio on immunostaining. Since IL-6 was not over-expressed in tissue of idiopathic multicentric Castleman’s disease, IL-6 may be produced outside the affected organs, and circulating IL-6 may lead to lymphoplasmacytosis at nodal and extranodal sites.
Morphological and neurochemical characterization of glycinergic neurons in laminae I-IV of the mouse spinal dorsal horn
The Journal of comparative neurology
Miranda, CO;Hegedüs, K;Wildner, H;Zeilhofer, HU;Antal, M;
PMID: 34382691 | DOI: 10.1002/cne.25232
A growing body of experimental evidence shows that glycinergic inhibition plays vital roles in spinal pain processing. In spite of this, however, our knowledge about the morphology, neurochemical characteristics, and synaptic relations of glycinergic neurons in the spinal dorsal horn is very limited. The lack of this knowledge makes our understanding about the specific contribution of glycinergic neurons to spinal pain processing quite vague. Here we investigated the morphology and neurochemical characteristics of glycinergic neurons in laminae I-IV of the spinal dorsal horn using a GlyT2::CreERT2-tdTomato transgenic mouse line. Confirming previous reports, we show that glycinergic neurons are sparsely distributed in laminae I-II, but their densities are much higher in lamina III and especially in lamina IV. First in the literature, we provide experimental evidence indicating that in addition to neurons in which glycine colocalizes with GABA, there are glycinergic neurons in laminae I-II that do not express GABA and can thus be referred to as glycine-only neurons. According to the shape and size of cell bodies and dendritic morphology, we divided the tdTomato-labeled glycinergic neurons into three and six morphological groups in laminae I-II and laminae III-IV, respectively. We also demonstrate that most of the glycinergic neurons co-express neuronal nitric oxide synthase, parvalbumin, the receptor tyrosine kinase RET, and the retinoic acid-related orphan nuclear receptor β (RORβ), but there might be others that need further neurochemical characterization. The present findings may foster our understanding about the contribution of glycinergic inhibition to spinal pain processing.
Gertler, TS;Cherian, S;DeKeyser, JM;Kearney, JA;George, AL;
PMID: 35346832 | DOI: 10.1016/j.nbd.2022.105713
KCNT1 encodes the sodium-activated potassium channel KNa1.1, expressed preferentially in the frontal cortex, hippocampus, cerebellum, and brainstem. Pathogenic missense variants in KCNT1 are associated with intractable epilepsy, namely epilepsy of infancy with migrating focal seizures (EIMFS), and sleep-related hypermotor epilepsy (SHE). In vitro studies of pathogenic KCNT1 variants support predominantly a gain-of-function molecular mechanism, but how these variants behave in a neuron or ultimately drive formation of an epileptogenic circuit is an important and timely question. Using CRISPR/Cas9 gene editing, we introduced a gain-of-function variant into the endogenous mouse Kcnt1 gene. Compared to wild-type (WT) littermates, heterozygous and homozygous knock-in mice displayed greater seizure susceptibility to the chemoconvulsants kainate and pentylenetetrazole (PTZ), but not to flurothyl. Using acute slice electrophysiology in heterozygous and homozygous Kcnt1 knock-in and WT littermates, we demonstrated that CA1 hippocampal pyramidal neurons exhibit greater amplitude of miniature inhibitory postsynaptic currents in mutant mice with no difference in frequency, suggesting greater inhibitory tone associated with the Kcnt1 mutation. To address alterations in GABAergic signaling, we bred Kcnt1 knock-in mice to a parvalbumin-tdTomato reporter line, and found that parvalbumin-expressing (PV+) interneurons failed to fire repetitively with large amplitude current injections and were more prone to depolarization block. These alterations in firing can be recapitulated by direct application of the KNa1.1 channel activator loxapine in WT but are occluded in knock-in littermates, supporting a direct channel gain-of-function mechanism. Taken together, these results suggest that KNa1.1 gain-of-function dampens interneuron excitability to a greater extent than it impacts pyramidal neuron excitability, driving seizure susceptibility in a mouse model of KCNT1-associated epilepsy.
Sauter MM, Brandt CR.
PMID: 27170050 | DOI: 10.1016/j.exer.2016.05.003
Injection of herpes simplex virus vectors into the vitreous of primate eyes induces an acute, transient uveitis. The purpose of this study was to characterize innate immune responses of macaque neural retina tissue to the herpes simplex virus type 1-based gene delivery vector hrR3. PCR array analysis demonstrated the induction of the pro-inflammatory cytokine IL-6, as well as the anti-inflammatory cytokine IL-10, following hrR3 exposure. Secretion of IL-6 was detected by ELISA and cone photoreceptors and Muller cells were the predominant IL-6 positive cell types. RNA in situ hybridization confirmed that IL-6 was expressed in photoreceptor and Muller cells. The IL-10 positive cells in the inner nuclear layer were identified as amacrine cells by immunofluorescence staining with calretinin antibody. hrR3 challenge resulted in activation of NFκB (p65) in Muller glial cells, but not in cone photoreceptors, suggesting a novel regulatory mechanism for IL-6 expression in cone cells. hrR3 replication was not required for IL-6 induction or NFκB (p65) activation. These data suggest a pro-inflammatory (IL-6)/anti-inflammatory (IL-10) axis exists in neural retina and the severity of acute posterior uveitis may be determined by this interaction. Further studies are needed to identify the trigger for IL-6 and IL-10 induction and the mechanism of IL-6 induction in cone cells.
International journal of molecular sciences
Miranda, CO;Hegedüs, K;Kis, G;Antal, M;
PMID: 37108107 | DOI: 10.3390/ijms24086943
A great deal of evidence supports the inevitable importance of spinal glycinergic inhibition in the development of chronic pain conditions. However, it remains unclear how glycinergic neurons contribute to the formation of spinal neural circuits underlying pain-related information processing. Thus, we intended to explore the synaptic targets of spinal glycinergic neurons in the pain processing region (laminae I-III) of the spinal dorsal horn by combining transgenic technology with immunocytochemistry and in situ hybridization accompanied by light and electron microscopy. First, our results suggest that, in addition to neurons in laminae I-III, glycinergic neurons with cell bodies in lamina IV may contribute substantially to spinal pain processing. On the one hand, we show that glycine transporter 2 immunostained glycinergic axon terminals target almost all types of excitatory and inhibitory interneurons identified by their neuronal markers in laminae I-III. Thus, glycinergic postsynaptic inhibition, including glycinergic inhibition of inhibitory interneurons, must be a common functional mechanism of spinal pain processing. On the other hand, our results demonstrate that glycine transporter 2 containing axon terminals target only specific subsets of axon terminals in laminae I-III, including nonpeptidergic nociceptive C fibers binding IB4 and nonnociceptive myelinated A fibers immunoreactive for type 1 vesicular glutamate transporter, indicating that glycinergic presynaptic inhibition may be important for targeting functionally specific subpopulations of primary afferent inputs.
Choi, BR;Johnson, KR;Maric, D;McGavern, DB;
PMID: 37248420 | DOI: 10.1038/s41590-023-01521-1
Cerebrovascular injury (CVI) is a common pathology caused by infections, injury, stroke, neurodegeneration and autoimmune disease. Rapid resolution of a CVI requires a coordinated innate immune response. In the present study, we sought mechanistic insights into how central nervous system-infiltrating monocytes program resident microglia to mediate angiogenesis and cerebrovascular repair after an intracerebral hemorrhage. In the penumbrae of human stroke brain lesions, we identified a subpopulation of microglia that express vascular endothelial growth factor A. These cells, termed 'repair-associated microglia' (RAMs), were also observed in a rodent model of CVI and coexpressed interleukin (IL)-6Ra. Cerebrovascular repair did not occur in IL-6 knockouts or in mice lacking microglial IL-6Ra expression and single-cell transcriptomic analyses revealed faulty RAM programming in the absence of IL-6 signaling. Infiltrating CCR2+ monocytes were the primary source of IL-6 after a CVI and were required to endow microglia with proliferative and proangiogenic properties. Faulty RAM programming in the absence of IL-6 or inflammatory monocytes resulted in poor cerebrovascular repair, neuronal destruction and sustained neurological deficits that were all restored via exogenous IL-6 administration. These data provide a molecular and cellular basis for how monocytes instruct microglia to repair damaged brain vasculature and promote functional recovery after injury.
Arthritis Rheumatol. 2015 Apr 27.
Makki MS, Haseeb A, Haqqi TM.
PMID: 25917063 | DOI: 10.1002/art.39173
Abstract OBJECTIVE: Enhanced IL-6 expression plays an important role in the pathogenesis of osteoarthritis (OA). MCPIP1 is a novel post-transcriptional regulator of IL-6 expression and is targeted by miR-9. We investigated the MCPIP1 expression in OA cartilage and explored whether targeting of MCPIP1 by miR-9 contributes to enhanced IL-6 expression in OA. METHODS: Gene and protein expression in IL-1β-stimulated human OA chondrocytes/cartilage was determined by TaqMan assays and immunoblotting respectively. MCPIP1 and IL-6 mRNA expression at single cell level was analyzed using RNAScopeTM . MCPIP1 protein interaction with IL-6 mRNA was investigated using RNA immunoprecipitation (RIP). Transient transfections were used for siRNA mediated knockdown and overexpression of MCPIP1, its RNAse defective mutant, miR-9 or antagomir. Role of signaling pathways was evaluated using small molecule inhibitors. Binding of miR-9 with the "seed sequence" in the 3'UTR of MCPIP1 mRNA was investigated using a luciferase reporter assay. RESULTS: MCPIP1 mRNA expression was low but expression of miR-9 and IL-6 was high in the damaged OA cartilage. In IL-1β-stimulated OA chondrocytes expression of miR-9 and MCPIP1 was mutually exclusive and increase in miR-9 expression level correlated with reduced MCPIP1 expression and enhanced IL-6 expression. MCPIP1 protein directly binds with IL-6 mRNA and over-expression of wild type MCPIP1 destabilized the IL-6 mRNA. MCPIP1 expression was altered by overexpression or inhibition of miR-9. Transfection with miR-9 mimics inhibited the reporter activity and mutation of the "seed sequence" abolished the repression of reporter activity. CONCLUSIONS: These studies implicate miR-9-mediated suppression of MCPIP1 in OA pathogenesis via upregulation of IL-6 expression in IL-1β-stimulated human OA chondrocytes. This article is protected by copyright. All rights reserved.
Cancer Prev Res (Phila). 2015 May 19.
Dietary carcinogens, such as 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), and chronic inflammation have each been implicated as etiological agents in prostate cancer. We hypothesized that bacterial prostatitis would accelerate PhIP-induced pre-invasive lesions in the rat prostate. Male Fischer 344 rats were assigned into 4 groups: Control (untreated), PhIP (200 ppm in the diet for 20 weeks), E. coli (prostatic inoculation in week 10), or PhIP+E. coli. Study animals were monitored for a total of 52 weeks and were euthanized as necessary based on strict criteria for health status and tumor burden. Animals treated with E. coli initially developed acute and chronic inflammation in all lobes of the prostate, whereas inflammation was observed predominantly in the ventral lobe at time of death. PhIP+E. coli-treated animals exhibited a marked decrease in survival compared to PhIP-alone treated animals as a result of an increase in the number of invasive cancers that developed at multiple sites including the skin, small intestine, and Zymbal's gland. Despite their earlier mortality, PhIP+E. coli-treated animals developed an increased average number of precancerous lesions within the prostate compared to PhIP-treated animals, with a significantly increased Ki-67 index. Multiplexed serum cytokine analysis indicated an increase in the level of circulating IL-6 and IL-12 in PhIP+E. coli-treated animals. Elevated serum IL-6 levels correlated with the development of precancerous lesions within the prostate. These results suggest that bacterial infections and dietary carcinogens - two conceivably preventable cancer risk factors - may synergistically promote tumorigenesis.
Albisetti GW, Pagani M, Platonova E, Hösli L, Johannssen HC, Fritschy JM, Wildner H, Zeilhofer HU.
PMID: PMID: 30655357 | DOI: DOI:10.1523/JNEUROSCI.2559-18.2019
Gastrin-releasing peptide (GRP) is a spinal itch transmitter expressed by a small population of dorsal horn interneurons (GRP neurons). The contribution of these neurons to spinal itch relay is still only incompletely understood and their potential contribution to pain-related behaviors remains controversial. Here, we have addressed this question in a series of experiments performed in GRP::cre and GRP::eGFP transgenic male mice. We combined behavioral tests with neuronal circuit tracing, morphology, chemogenetics, optogenetics, and electrophysiology to obtain a more comprehensive picture. We found that GRP neurons form a rather homogenous population of central cell-like excitatory neurons located in lamina II of the superficial dorsal horn. Multicolor high-resolution confocal microscopy and optogenetic experiments demonstrated that GRP neurons receive direct input from MrgprA3-positive pruritoceptors. Anterograde herpes simplex virus-based neuronal tracing initiated from GRP neurons revealed ascending polysynaptic projections to distinct areas and nuclei in the brainstem, midbrain, thalamus, and the somatosensory cortex. Spinally restricted ablation of GRP neurons reduced itch-related behaviors to different pruritogens while their chemogenetic excitation elicited itch-like behaviors and facilitated responses to several pruritogens. By contrast, responses to painful stimuli remained unaltered. These data confirm a critical role of dorsal horn GRP neurons in spinal itch transmission, but do not support a role in pain.Significance statement: Dorsal horn GRP neurons serve a well-established function in the spinal transmission of pruritic (itch) signals. A potential role in the transmission of nociceptive (pain) signals has remained controversial. Our results provide further support for a critical role of dorsal horn GRP neurons in itch circuits, but we failed to find evidence supporting a role in pain.
Short KR, Veeris R, Leijten LM, van den Brand JM, Jong VL, Stittelaar K, Osterhaus ADME, Andeweg A, van Riel D.
Short KR, Veeris R, Leijten LM, van den Brand JM, Jong VL, Stittelaar K, Osterhaus ADME, Andeweg A, van Riel D.
PMID: - | DOI: 10.1093/infdis/jix281
Severe influenza is often associated with disease manifestations outside the respiratory tract. Whilst pro-inflammatory cytokines can be detected in the lungs and blood of infected patients, the role of extra-respiratory organs in the production of pro-inflammatory cytokines is unknown. Here, we show that both pandemic H1N1 and highly pathogenic H5N1 virus induce expression of TNFα, IL-6 and IL-8 in the respiratory tract and central nervous system. In addition, H5N1 virus induced cytokines in the heart, pancreas, spleen, liver and jejunum. Together, these data suggest that extra-respiratory tissues contribute to systemic cytokine responses which may increase the severity of influenza.
