Smith HL, Freeman OJ, Butcher AJ, Holmqvist S, Humoud I, Sch�tzl T, Hughes DT, Verity NC, Swinden DP, Hayes J, de Weerd L, Rowitch DH, Franklin RJM, Mallucci GR
PMID: 31924446 | DOI: 10.1016/j.neuron.2019.12.014
Recent interest in astrocyte activation states has raised the fundamental question of how these cells, normally essential for synapse and neuronal maintenance, become pathogenic. Here, we show that activation of the unfolded protein response (UPR), specifically phosphorylated protein kinase R-like endoplasmic reticulum (ER) kinase (PERK-P) signaling-a pathway that is widely dysregulated in neurodegenerative diseases-generates a distinct reactivity state in astrocytes that alters the astrocytic secretome, leading to loss of synaptogenic function in vitro. Further, we establish that the same PERK-P-dependent astrocyte reactivity state is harmful to neurons in vivo in mice with prion neurodegeneration. Critically, targeting this signaling exclusively in astrocytes during prion disease is alone sufficient to prevent neuronal loss and significantly prolongs survival. Thus, the astrocyte reactivity state resulting from UPR over-activation is a distinct pathogenic mechanism that can by itself be effectively targeted for neuroprotection
Suzuki T, Sato Y, Sano K, Arashiro T, Katano H, Nakajima N, Shimojima M, Kataoka M, Takahashi K, Wada Y, Morikawa S, Fukushi S, Yoshikawa T, Saijo M, Hasegawa H
PMID: 31904586 | DOI: 10.1172/JCI129171
Severe fever with thrombocytopenia syndrome (SFTS) is an emerging hemorrhagic fever caused by a tick-borne banyangvirus and is associated with high fatality. Despite increasing incidence of SFTS and serious public health concerns in East Asia, the pathogenesis of lethal SFTS virus (SFTSV) infection in humans is not fully understood. Numbers of postmortem examinations to determine target cells of the viral infection have so far been limited. Here we showed that B cells differentiating into plasmablasts and macrophages in secondary lymphoid organs were targets for SFTSV at the end stage of lethal infection, and the majority of SFTSV-infected cells were B cell-lineage lymphocytes. In affected individuals, B cell-lineage lymphocytes with SFTSV infection were widely distributed in both lymphoid and nonlymphoid organs, and infiltration of these cells into the capillaries of the organs could be observed occasionally. Moreover, a human plasmablastic lymphoma cell line, PBL-1, was susceptible to SFTSV propagation and had a similar immunophenotype to that of target cells of SFTSV in fatal SFTS. PBL-1 can therefore provide a potential in vitro model for human SFTSV infection. These results extend our understanding of the pathogenesis of human lethal SFTSV infection and can facilitate the development of SFTSV countermeasures.
Heather C. Rice, Gabriele Marcassa, Iordana Chrysidou,Katrien Horr�Tracy L. Young-Pearse, Ulrike C. M�ller, Takashi Saito Takaomi C. Saido, Robert Vassar, Joris de Wit,and Bart De Strooper
PMID: 31915042 | DOI: 10.1186/s13024-019-0356-y
The amyloid-? (A?) peptide, the primary constituent of amyloid plaques found in Alzheimer�s disease (AD) brains, is derived from sequential proteolytic processing of the Amyloid Precursor Protein (APP). However, the contribution of different cell types to A? deposition has not yet been examined in an in vivo, non-overexpression system. Here, we show that endogenous APP is highly expressed in a heterogeneous subset of GABAergic interneurons throughout various laminae of the hippocampus, suggesting that these cells may have a profound contribution to AD plaque pathology. We then characterized the laminar distribution of amyloid burden in the hippocampus of an APP knock-in mouse model of AD. To examine the contribution of GABAergic interneurons to plaque pathology, we blocked A? production specifically in these cells using a cell type-specific knock-out of BACE1. We found that during early stages of plaque deposition, interneurons contribute to approximately 30% of the total plaque load in the hippocampus. The greatest contribution to plaque load (75%) occurs in the stratum pyramidale of CA1, where plaques in human AD cases are most prevalent and where pyramidal cell bodies and synaptic boutons from perisomatic-targeting interneurons are located. These findings reveal a crucial role of GABAergic interneurons in the pathology of AD. Our study also highlights the necessity of using APP knock-in models to correctly evaluate the cellular contribution to amyloid burden since APP overexpressing transgenic models drive expression in cell types according to the promoter and integration site and not according to physiologically relevant expression mechanisms.
Hailong Ma Hanyue Chang, Wenyi Yang, Yusheng Lu,Jingzhou Huand Shufang Jin
PMID: 31907020 | DOI: 10.1186/s12943-019-1123-y
Background
Interferon alpha (IFN?) is a well-established regulator of immunosuppression in head and neck squamous cell carcinoma (HNSCC), while the role of long noncoding RNAs (lncRNAs) in immunosuppression remains largely unknown.
Methods
Differentially expressed lncRNAs were screened under IFN? stimulation using lncRNA sequencing. The role and mechanism of lncRNA in immunosuppression were investigated in HNSCC in vitro and in vivo.
Results
We identified a novel IFN?-induced upregulated lncRNA, lncMX1ヨ215, in HNSCC. LncMX1ヨ215 was primarily located in the cell nucleus. Ectopic expression of lncMX1ヨ215 markedly inhibited expression of the IFN?-induced, immunosuppression-related molecules programmed cell death 1 ligand 1 (PD-L1) and galectin-9, and vice versa. Subsequently, histone deacetylase (HDAC) inhibitors promoted the expression of PD-L1 and galectin-9. Binding sites for H3K27 acetylation were found on PD-L1 and galectin-9 promoters. Mechanistically, we found that lncMX1ヨ215 directly interacted with GCN5, a known H3K27 acetylase, to interrupt its binding to H3K27 acetylation. Clinically, negative correlations between lncMX1ヨ215 and PD-L1 and galectin-9 expression were observed. Finally, overexpression of lncMX1ヨ215 suppressed HNSCC proliferation and metastasis capacity in vitro and in vivo.
Conclusions
Our results suggest that lncMX1ヨ215 negatively regulates immunosuppression by interrupting GCN5/H3K27ac binding in HNSCC, thus providing novel insights into immune checkpoint blockade treatment
Bizunesh Abere, Jinghui Li, Hongzhao Zhou, Tuna Toptan, Patrick S. Moore, Yuan Chang
PMID: 31911496 | DOI: 10.1128/mBio.03027-19
Kaposiメs sarcoma-associated herpesvirus (KSHV) has recently been found to generate circular RNAs (circRNAs) from several KSHV genes, most abundantly from K10 (viral interferon regulatory factor 4 [vIRF4]), K7.3, and polyadenylated nuclear (PAN) RNA. To define expression of these circRNAs, KSHV-infected cell lines, patient tissues, and purified virions were examined. KSHV circRNA expression was universally detected in tests of six primary effusion lymphoma (PEL) cell lines but ranged from low-level expression in BC-1 cells dually infected with tightly latent KSHV and Epstein-Barr virus to abundant expression in KSHV-only BCBL-1 cells with spontaneous virus production. Generally, the PAN/K7.3 locus broadly and bidirectionally generated circRNA levels that paralleled the corresponding linear RNA levels. However, RNA corresponding to a particular KSHV circularization site (circ-vIRF4) was minimally induced, despite linear vIRF4 RNA being activated by virus induction. In situ hybridization showed abundant circ-vIRF4 in noninduced PEL cells. All three KSHV circRNAs were isolated as nuclease-protected forms from gradient-purified virions collected from BrK.219 cells infected with a KSHV molecular clone. For circ-vIRF4, the fully processed form that is exported to the cytoplasm was incorporated into virus particles but the nuclear, intron-retaining form was not. The half-life of circ-vIRF4 was twice as long as that of its linear counterpart. The KSHV circRNAs could be detected at a higher rate than their corresponding linear counterparts by in situ hybridization in archival tissues and by reverse transcription-PCR (RT-PCR) in sera stored for over 25?years. In summary, KSHV circRNAs are expressed in infection-associated diseases, can be regulated depending on virus life cycle, and are incorporated into viral particles for preformed delivery, suggesting a potential function in early infection
A Spatiomolecular Map of the Striatum
Antje M�rtin, Daniela Calvigioni, Ourania Tzortzi, Janos Fuzik, Emi lW�rnberg, Konstantinos Meletis
| DOI: 10.1016/j.celrep.2019.11.096
The striatum is organized into two major outputs formed by striatal projection neuron (SPN) subtypes with distinct molecular identities. In addition, histochemical division into patch and matrix compartments represents an additional spatial organization, proposed to mirror a motor-motivation regionalization. To map the molecular diversity of patch versus matrix SPNs, we genetically labeled mu opioid receptor (Oprm1) expressing neurons and performed single-nucleus RNA sequencing. This allowed us to establish molecular definitions of patch, matrix, and exopatch SPNs, as well as identification of Col11a1+ striatonigral SPNs. At the tissue level, mapping the expression of candidate markers reveals organization of spatial domains, which are conserved in the non-human primate brain. The spatial markers are cell-type independent and instead represent a spatial code found across all SPNs within a spatial domain. The spatiomolecular map establishes a formal system for targeting and studying striatal subregions and SPNs subtypes, beyond the classical striatonigral and striatopallidal division
Kim SH, Da Cruz Paula A, Basili T, Dopeso H, Bi R, Pareja F, da Silva EM, Gularte-M�rida R, Sun Z, Fujisawa S, Smith CG, Ferrando L, Martins Sebasti�o AP, Bykov Y, Li A, Silveira C, Ashley CW, Stylianou A, Selenica P, Samore WR, Jungbluth AA, Zamarin D, Abu-Rustum NR, Helin K4,, Soslow RA, Reis-Filho JS, Oliva E, Weigelt B
PMID: 31896750 | DOI: 10.1038/s41467-019-13806-x
Sclerosing stromal tumor (SST) of the ovary is a rare type of sex cord-stromal tumor (SCST), whose genetic underpinning is currently unknown. Here, using whole-exome, targeted capture and RNA-sequencing, we report recurrent FHL2-GLI2 fusion genes in 65% (17/26) of SSTs and other GLI2 rearrangements in additional 15% (4/26) SSTs, none of which are detected in other types of SCSTs (n?=?48) or common cancer types (n?=?9,950). The FHL2-GLI2 fusions result in transcriptomic activation of the Sonic Hedgehog (SHH) pathway in SSTs. Expression of the FHL2-GLI2 fusion in vitro leads to the acquisition of phenotypic characteristics of SSTs, increased proliferation, migration and colony formation, and SHH pathway activation. Targeted inhibition of the SHH pathway results in reversal of these oncogenic properties, indicating its role in the pathogenesis of SSTs. Our results demonstrate that the FHL2-GLI2 fusion is likely the oncogenic driver of SSTs, defining a genotypic-phenotypic correlation in ovarian neoplasms
Pascalin eAim�, Saravanan S.Karuppagounder, Apeksha Rao, Yingxin Chen, Robert E.Burke, Rajiv R.Ratan, Lloyd A.Greene
PMID: 31911115 | DOI: 10.1016/j.nbd.2019.104725
Identifying disease-causing pathways and drugs that target them in Parkinson's disease (PD) has remained challenging. We uncovered a PD-relevant pathway in which the stress-regulated heterodimeric transcription complex CHOP/ATF4 induces the neuron prodeath protein Trib3 that in turn depletes the neuronal survival protein Parkin. Here we sought to determine whether the drug adaptaquin, which inhibits ATF4-dependent transcription, could suppress Trib3 induction and neuronal death in cellular and animal models of PD. Neuronal PC12 cells and ventral midbrain dopaminergic neurons were assessed in vitro for survival, transcription factor levels and Trib3 or Parkin expression after exposure to 6-hydroxydopamine or 1-methyl-4-phenylpyridinium with or without adaptaquin co-treatment. 6-hydroxydopamine injection into the medial forebrain bundle was used to examine the effects of systemic adaptaquin on signaling, substantia nigra dopaminergic neuron survival and striatal projections as well as motor behavior. In both culture and animal models, adaptaquin suppressed elevation of ATF4 and/or CHOP and induction of Trib3 in response to 1-methyl-4-phenylpyridinium and/or 6-hydroxydopamine. In culture, adaptaquin preserved Parkin levels, provided neuroprotection and preserved morphology. In the mouse model, adaptaquin treatment enhanced survival of dopaminergic neurons and substantially protected their striatal projections. It also significantly enhanced retention of nigrostriatal function. These findings define a novel pharmacological approach involving the drug adaptaquin, a selective modulator of hypoxic adaptation, for suppressing Parkin loss and neurodegeneration in toxin models of PD. As adaptaquin possesses an oxyquinoline backbone with known safety in humans, these findings provide a firm rationale for advancing it towards clinical evaluation in PD
Wan XQ, Zeng F, Huang XF, Yang HQ, Wang L, Shi YC, Zhang ZH, Lin S
PMID: 31880085 | DOI: 10.1111/cns.13281
AIMS:
Many patients taking risperidone for the treatment of psychiatric disorders experience substantial body weight gain. Researchers have speculated that risperidone induces obesity by modulating central signals; however, the precise central mechanisms involved remain to be fully elucidated.
METHODS:
Twenty-four C57BL/6J mice were divided into four groups: a control group; a risperidone-treated group; a lorcaserin-treated group; and a combined risperidone + lorcaserin-treated group. The mice were received the corresponding treatments for 4 weeks, and their brains were collected for in situ hybridization analysis. A subset of C57BL/6J mice was administrated with risperidone or placebo, and brains were collected 60 minutes post-treatment for determination of c-fos activity. In addition, brains of NPY-GFP mice treated with or without risperidone were collected to perform colocalization of NPY and c-fos, as well as NPY and 5-HT2c receptor using immunohistochemistry.
RESULTS:
There was significantly elevated c-fos expression in the hypothalamic arcuate nucleus (Arc) of risperidone-treated mice. More than 68% c-fos-positive neurons were NPY-expressing neurons. Furthermore, in situ hybridization revealed that Arc NPY mRNA expression was significantly increased in the risperidone-treated group compared with control group. Moreover, we identified that 95% 5-HT2c receptors were colocalized with NPY positive neurons, and increased Arc NPY mRNA expression induced by risperidone was markedly reduced by cotreatment with lorcaserin, a specific 5-HT2c receptor agonist.
CONCLUSION:
Our findings provide critical insight into the mechanisms underlying antipsychotic-induced obesity, which may assist the development of therapeutic strategies to address metabolic side effects of risperidone.
L�ken OM, Bj�rgen H, Hordvik I, Koppang EO
PMID: 31877586 | DOI: 10.1111/joa.13147
The bursa of Fabricius is a primary and secondary lymphoid organ considered exclusively present in birds, and studies of this structure have been vital to our current understanding of the adaptive immune system of vertebrates. In this study, we reveal substantial lymphoepithelial tissue in a previously undescribed bursa in Atlantic salmon (Salmo salar), situated caudal to the urogenital papilla of the cloaca and thus analogous to the anatomical placement of the bursa of Fabricius. We investigated three groups of Atlantic salmon at different maturational stages and characterized the structure by applying dissection, radiology, scanning electron microscopy and histological techniques, including immunohistochemistry and in situ hybridization. We found that the epithelial anlage of the salmon cloacal bursa developed into substantial lymphoepithelial tissue and subsequently regressed following sexual maturation. Such a dynamic development is also a key characteristic of the avian bursa. The presence of intraepithelial lymphocytes was concomitant with expression of the leukocyte-attracting chemokine CCL19, indicative of lymphoid organ functions. We did not observe recombination or gene conversion in salmon bursal lymphocytes at any developmental stage, indicating the absence of primary lymphoid organ functions in contrast to the bursa of Fabricius. However, the possibility of the bursa to trap both enteric and environmental antigens, combined with the presence of several antigen-presenting cells residing within the lymphoepithelium, suggest the structure has secondary lymphoid organ functions. We present the discovery of a lymphoid organ in Atlantic salmon with striking topographical similarities to that of the bursa of Fabricius in birds. In addition, the age-dependent dynamics of its lymphoepithelium suggest functions related to the maturation processes of lymphocytes.
Novellasdemunt L, Kucharska A, Jamieson C, Prange-Barczynska M, Baulies A, Antas P, van der Vaart J, Gehart H, Maurice MM, Li VS
PMID: 31867777 | DOI: 10.15252/embj.2019102771
The intestinal stem cell (ISC) marker LGR5 is a receptor for R-spondin (RSPO) that functions to potentiate Wnt signalling in the proliferating crypt. It has been recently shown that Wnt plays a priming role for ISC self-renewal by inducing RSPO receptor LGR5 expression. Despite its pivotal role in homeostasis, regeneration and cancer, little is known about the post-translational regulation of LGR5. Here, we show that the HECT-domain E3 ligases NEDD4 and NEDD4L are expressed in the crypt stem cell regions and regulate ISC priming by degrading LGR receptors. Loss of Nedd4 and Nedd4l enhances ISC proliferation, increases sensitivity to RSPO stimulation and accelerates tumour development in Apcmin mice with increased numbers of high-grade adenomas. Mechanistically, we find that both NEDD4 and NEDD4L negatively regulate Wnt/?-catenin signalling by targeting LGR5 receptor and DVL2 for proteasomal and lysosomal degradation. Our findings unveil the previously unreported post-translational control of LGR receptors via NEDD4/NEDD4L to regulate ISC priming. Inactivation of NEDD4 and NEDD4L increases Wnt activation and ISC numbers, which subsequently enhances tumour predisposition and progression.
Kanaya M, Higo S, Ozawa H
PMID: 31877966 | DOI: 10.3390/ijms21010115
Estrogens play an essential role in multiple physiological functions in the brain, including reproductive neuroendocrine, learning and memory, and anxiety-related behaviors. To determine these estrogen functions, many studies have tried to characterize neurons expressing estrogen receptors known as ER? and ER?. However, the characteristics of ER?-expressing neurons in the rat brain still remain poorly understood compared to that of ER?-expressing neurons. The main aim of this study is to determine the neurochemical characteristics of ER?-expressing neurons in the rat hypothalamus using RNAscope in situ hybridization (ISH) combined with immunofluorescence. Strong Esr2 signals were observed especially in the anteroventral periventricular nucleus (AVPV), bed nucleus of stria terminalis, hypothalamic paraventricular nucleus (PVN), supraoptic nucleus, and medial amygdala, as previously reported. RNAscope ISH with immunofluorescence revealed that more than half of kisspeptin neurons in female AVPV expressed Esr2, whereas few kisspeptin neurons were found to co-express Esr2 in the arcuate nucleus. In the PVN, we observed a high ratio of Esr2 co-expression in arginine-vasopressin neurons and a low ratio in oxytocin and corticotropin-releasing factor neurons. The detailed neurochemical characteristics of ER?-expressing neurons identified in the current study can be very essential to understand the estrogen signaling via ER?.