Liu QR, Huang NS, Qu H, O’Connell JF, Gonzalez-Mariscal I, Santa-Cruz-Calvo S, Doyle ME, Xi ZX, Wang Y, Onaivi ES, Egan J.
PMID: 30202012 | DOI: 10.1038/s41401-018-0152-1
Targeting peripheral CB1R is desirable for the treatment of metabolic syndromes without adverse neuropsychiatric effects. We previously reported a human hCB1b isoform that is selectively enriched in pancreatic beta-cells and hepatocytes, providing a potential peripheral therapeutic hCB1R target. It is unknown whether there are peripherally enriched mouse and rat CB1R (mCB1 and rCB1, respectively) isoforms. In this study, we found no evidence of peripherally enriched rodent CB1 isoforms; however, some mCB1R isoforms are absent in peripheral tissues. We show that the mouse Cnr1 gene contains six exons that are transcribed from a single promoter. We found that mCB1A is a spliced variant of extended exon 1 and protein-coding exon 6; mCB1B is a novel spliced variant containing unspliced exon 1, intron 1, and exon 2, which is then spliced to exon 6; and mCB1C is a spliced variant including all 6 exons. Using RNAscope in situ hybridization, we show that the isoforms mCB1A and mCB1B are expressed at a cellular level and colocalized in GABAergic neurons in the hippocampus and cortex. RT-qPCR reveals that mCB1A and mCB1B are enriched in the brain, while mCB1B is not expressed in the pancreas or the liver. Rat rCB1R isoforms are differentially expressed in primary cultured neurons, astrocytes, and microglia. We also investigated modulation of Cnr1 expression by insulin in vivo and carried out in silico modeling of CB1R with JD5037, a peripherally restricted CB1R inverse agonist, using the published crystal structure of hCB1R. The results provide models for future CB1R peripheral targeting.
Pharmaceuticals (Basel, Switzerland)
Konkoly, J;Kormos, V;Gaszner, B;Sándor, Z;Kecskés, A;Alomari, A;Szilágyi, A;Szilágyi, B;Zelena, D;Pintér, E;
PMID: 34959735 | DOI: 10.3390/ph14121336
Transient receptor potential ankyrin 1 (TRPA1), a nonselective cation channel, contributes to several (patho)physiological processes. Smell loss is an early sign in several neurodegenerative disorders, such as multiple sclerosis, Parkinson's and Alzheimer's diseases; therefore, we focused on its role in olfaction and social behaviour with the aim to reveal its potential therapeutic use. The presence of Trpa1 mRNA was studied along the olfactory tract of mice by combined RNAscope in situ hybridisation and immunohistochemistry. The aversive effects of fox and cat odour were examined in parallel with stress hormone levels. In vitro calcium imaging was applied to test if these substances can directly activate TRPA1 receptors. The role of TRPA1 in social behaviour was investigated by comparing Trpa1 wild-type and knockout mice (KO). Trpa1 mRNA was detected in the olfactory bulb and piriform cortex, while its expression was weak in the olfactory epithelium. Fox, but not cat odour directly activated TRPA1 channels in TRPA1-overexpressing Chinese Hamster Ovary cell lines. Accordingly, KO animals showed less aversion against fox, but not cat odour. The social interest of KO mice was reduced during social habituation-dishabituation and social interaction, but not during resident-intruder tests. TRPA1 may contribute to odour processing at several points of the olfactory tract and may play an important role in shaping the social behaviour of mice. Thus, TRPA1 may influence the development of certain social disorders, serving as a potential drug target in the future.
Zhao, M;Su, HZ;Zeng, YH;Sun, Y;Guo, XX;Li, YL;Wang, C;Zhao, ZY;Huang, XJ;Lin, KJ;Ye, ZL;Lin, BW;Hong, S;Zheng, J;Liu, YB;Yao, XP;Yang, D;Lu, YQ;Chen, HZ;Zuo, E;Yang, G;Wang, HT;Huang, CW;Lin, XH;Cen, Z;Lai, LL;Zhang, YK;Li, X;Lai, T;Lin, J;Zuo, DD;Lin, MT;Liou, CW;Kong, QX;Yan, CZ;Xiong, ZQ;Wang, N;Luo, W;Zhao, CP;Cheng, X;Chen, WJ;
PMID: 36443312 | DOI: 10.1038/s41421-022-00475-2
Brain calcification is a critical aging-associated pathology and can cause multifaceted neurological symptoms. Cerebral phosphate homeostasis dysregulation, blood-brain barrier defects, and immune dysregulation have been implicated as major pathological processes in familial brain calcification (FBC). Here, we analyzed two brain calcification families and identified calcification co-segregated biallelic variants in the CMPK2 gene that disrupt mitochondrial functions. Transcriptome analysis of peripheral blood mononuclear cells (PBMCs) isolated from these patients showed impaired mitochondria-associated metabolism pathways. In situ hybridization and single-cell RNA sequencing revealed robust Cmpk2 expression in neurons and vascular endothelial cells (vECs), two cell types with high energy expenditure in the brain. The neurons in Cmpk2-knockout (KO) mice have fewer mitochondrial DNA copies, down-regulated mitochondrial proteins, reduced ATP production, and elevated intracellular inorganic phosphate (Pi) level, recapitulating the mitochondrial dysfunction observed in the PBMCs isolated from the FBC patients. Morphologically, the cristae architecture of the Cmpk2-KO murine neurons was also impaired. Notably, calcification developed in a progressive manner in the homozygous Cmpk2-KO mice thalamus region as well as in the Cmpk2-knock-in mice bearing the patient mutation, thus phenocopying the calcification pathology observed in the patients. Together, our study identifies biallelic variants of CMPK2 as novel genetic factors for FBC; and demonstrates how CMPK2 deficiency alters mitochondrial structures and functions, thereby highlighting the mitochondria dysregulation as a critical pathogenic mechanism underlying brain calcification.
Somatostatin Interneurons of the Insula Mediate QR2-Dependent Novel Taste Memory Enhancement
Gould, NL;Kolatt Chandran, S;Kayyal, H;Edry, E;Rosenblum, K;
PMID: 34518366 | DOI: 10.1523/ENEURO.0152-21.2021
Forming long-term memories is crucial for adaptive behavior and survival in changing environments. The molecular consolidation processes which underlie the formation of these long-term memories are dependent on protein synthesis in excitatory and SST-expressing neurons. A centrally important, parallel process to this involves the removal of the memory constraint quinone reductase 2 (QR2), which has been recently shown to enhance memory consolidation for novel experiences in the cortex and hippocampus, via redox modulation. However, it is unknown within which cell type in the cortex removal of QR2 occurs, nor how this affects neuronal function. Here, we use novel taste learning in the mouse anterior insular cortex (aIC) to show that similarly to mRNA translation, QR2 removal occurs in excitatory and SST-expressing neurons. Interestingly, both novel taste and QR2 inhibition reduce excitability specifically within SST, but not excitatory neurons. Furthermore, reducing QR2 expression in SST, but not in PV or excitatory neurons, is sufficient to enhance taste memory. Thus, QR2 mediated intrinsic property changes of SST interneurons in the aIC is a central removable factor to allow novel taste memory formation. This previously unknown involvement of QR2 and SST interneurons in resetting aIC activity hours following learning, describes a molecular mechanism to define cell circuits for novel information. Therefore, the QR2 pathway in SST interneurons provides a fresh new avenue by which to tackle age-related cognitive deficits, while shedding new light onto the functional machinations of long-term memory formation for novel information.
Incerto-thalamic modulation of fear via GABA and dopamine
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
Venkataraman, A;Hunter, SC;Dhinojwala, M;Ghebrezadik, D;Guo, J;Inoue, K;Young, LJ;Dias, BG;
PMID: 33864008 | DOI: 10.1038/s41386-021-01006-5
Fear generalization and deficits in extinction learning are debilitating dimensions of Post-Traumatic Stress Disorder (PTSD). Most understanding of the neurobiology underlying these dimensions comes from studies of cortical and limbic brain regions. While thalamic and subthalamic regions have been implicated in modulating fear, the potential for incerto-thalamic pathways to suppress fear generalization and rescue deficits in extinction recall remains unexplored. We first used patch-clamp electrophysiology to examine functional connections between the subthalamic zona incerta and thalamic reuniens (RE). Optogenetic stimulation of GABAergic ZI → RE cell terminals in vitro induced inhibitory post-synaptic currents (IPSCs) in the RE. We then combined high-intensity discriminative auditory fear conditioning with cell-type-specific and projection-specific optogenetics in mice to assess functional roles of GABAergic ZI → RE cell projections in modulating fear generalization and extinction recall. In addition, we used a similar approach to test the possibility of fear generalization and extinction recall being modulated by a smaller subset of GABAergic ZI → RE cells, the A13 dopaminergic cell population. Optogenetic stimulation of GABAergic ZI → RE cell terminals attenuated fear generalization and enhanced extinction recall. In contrast, optogenetic stimulation of dopaminergic ZI → RE cell terminals had no effect on fear generalization but enhanced extinction recall in a dopamine receptor D1-dependent manner. Our findings shed new light on the neuroanatomy and neurochemistry of ZI-located cells that contribute to adaptive fear by increasing the precision and extinction of learned associations. In so doing, these data reveal novel neuroanatomical substrates that could be therapeutically targeted for treatment of PTSD.
Front Cell Neurosci. 2018 Oct 9;12:341.
Yoo T, Cho H, Lee J, Park H, Yoo YE, Yang E, Kim JY, Kim H, Kim E.
PMID: 30356810 | DOI: 10.3389/fncel.2018.00341
Shank3 is an excitatory postsynaptic scaffolding protein implicated in multiple brain disorders, including autism spectrum disorders (ASD) and Phelan-McDermid syndrome (PMS). Although previous neurobiological studies on Shank3 and Shank3-mutant mice have revealed diverse roles of Shank3 in the regulation of synaptic, neuronal and brain functions, whether Shank3 expression in specific cell types distinctly contributes to mouse phenotypes remains largely unclear. In the present study, we generated two Shank3-mutant mouse lines (exons 14-16) carrying global and GABA neuron-specific deletions and characterized their electrophysiological and behavioral phenotypes. These mouse lines show similar decreases in excitatory synaptic input onto dorsolateral striatal neurons. In addition, the abnormal social and locomotor behaviors observed in global Shank3-mutant mice are strongly mimicked by GABA neuron-specific Shank3-mutant mice, whereas the repetitive and anxiety-like behaviors are only partially mimicked. These results suggest that GABAergic Shank3 (exons 14-16) deletion has strong influences on striatal excitatory synaptic transmission and social and locomotor behaviors in mice.
Himmel LE, Hackett TA, Moore JL, Adams WR, Thomas G, Novitskaya T, Caprioli RM, Zijlstra A, Mahadevan-Jansen A, Boyd KL.
PMID: 30462242 | DOI: 10.1093/ilar/ily004
For decades, histopathology with routine hematoxylin and eosin staining has been and remains the gold standard for reaching a morphologic diagnosis in tissue samples from humans and veterinary species. However, within the past decade, there has been exponential growth in advanced techniques for in situ tissue biomarker imaging that bridge the divide between anatomic and molecular pathology. It is now possible to simultaneously observe localization and expression magnitude of multiple protein, nucleic acid, and molecular targets in tissue sections and apply machine learning to synthesize vast, image-derived datasets. As these technologies become more sophisticated and widely available, a team-science approach involving subspecialists with medical, engineering, and physics backgrounds is critical to upholding quality and validity in studies generating these data. The purpose of this manuscript is to detail the scientific premise, tools and training, quality control, and data collection and analysis considerations needed for the most prominent advanced imaging technologies currently applied in tissue sections: immunofluorescence, in situ hybridization, laser capture microdissection, matrix-assisted laser desorption ionization imaging mass spectrometry, and spectroscopic/optical methods. We conclude with a brief overview of future directions for ex vivo and in vivo imaging techniques.
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.
Molecular therapy : the journal of the American Society of Gene Therapy
Tadokoro, T;Bravo-Hernandez, M;Agashkov, K;Kobayashi, Y;Platoshyn, O;Navarro, M;Marsala, S;Miyanohara, A;Yoshizumi, T;Shigyo, M;Krotov, V;Juhas, S;Juhasova, J;Nguyen, D;Kupcova Skalnikova, H;Motlik, J;Studenovska, H;Proks, V;Reddy, R;Driscoll, SP;Glenn, TD;Kemthong, T;Malaivijitnond, S;Tomori, Z;Vanicky, I;Kakinohana, M;Pfaff, SL;Ciacci, J;Belan, P;Marsala, M;
PMID: 35524407 | DOI: 10.1016/j.ymthe.2022.04.023
Second-order spinal cord excitatory neurons play a key role in spinal processing and transmission of pain signals to the brain. Exogenously induced change in developmentally imprinted excitatory neurotransmitter phenotypes of these neurons to inhibitory has not yet been achieved. Here, we use a subpial dorsal horn-targeted delivery of AAV (adeno-associated virus) vector(s) encoding GABA (gamma-aminobutyric acid) synthesizing-releasing inhibitory machinery in mice with neuropathic pain. Treated animals showed a progressive and complete reversal of neuropathic pain (tactile and brush-evoked pain behavior) that persisted for a minimum of 2.5 months post-treatment. The mechanism of this treatment effect results from the switch of excitatory to preferential inhibitory neurotransmitter phenotype in dorsal horn nociceptive neurons and a resulting increase in inhibitory activity in regional spinal circuitry after peripheral nociceptive stimulation. No detectable side effects (e.g., sedation, motor weakness, loss of normal sensation) were seen between 2 and 13 months post-treatment in naive adult mice, pigs, and non-human primates. The use of this treatment approach may represent a potent and safe treatment modality in patients suffering from spinal cord or peripheral nerve injury-induced neuropathic pain.
Proceedings of the National Academy of Sciences of the United States of America
Kim, J;Park, D;Seo, NY;Yoon, TH;Kim, GH;Lee, SH;Seo, J;Um, JW;Lee, KJ;Ko, J;
PMID: 35022233 | DOI: 10.1073/pnas.2110196119
Synaptic cell-adhesion molecules (CAMs) organize the architecture and properties of neural circuits. However, whether synaptic CAMs are involved in activity-dependent remodeling of specific neural circuits is incompletely understood. Leucine-rich repeat transmembrane protein 3 (LRRTM3) is required for the excitatory synapse development of hippocampal dentate gyrus (DG) granule neurons. Here, we report that Lrrtm3-deficient mice exhibit selective reductions in excitatory synapse density and synaptic strength in projections involving the medial entorhinal cortex (MEC) and DG granule neurons, accompanied by increased neurotransmitter release and decreased excitability of granule neurons. LRRTM3 deletion significantly reduced excitatory synaptic innervation of hippocampal mossy fibers (Mf) of DG granule neurons onto thorny excrescences in hippocampal CA3 neurons. Moreover, LRRTM3 loss in DG neurons significantly decreased mossy fiber long-term potentiation (Mf-LTP). Remarkably, silencing MEC-DG circuits protected against the decrease in the excitatory synaptic inputs onto DG and CA3 neurons, excitability of DG granule neurons, and Mf-LTP in Lrrtm3-deficient mice. These results suggest that LRRTM3 may be a critical factor in activity-dependent synchronization of the topography of MEC-DG-CA3 excitatory synaptic connections. Collectively, our data propose that LRRTM3 shapes the target-specific structural and functional properties of specific hippocampal circuits.
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
Alvarez-Bagnarol, Y;García, R;Vendruscolo, LF;Morales, M;
PMID: 37270620 | DOI: 10.1038/s41386-023-01620-5
Opioid withdrawal signs, such as hyperalgesia, are manifestations of opioid use disorder that may contribute to opioid seeking and taking. We have previously identified an association between dorsal raphe (DR) neurons and the expression of hyperalgesia during spontaneous heroin withdrawal. Here, we found that chemogenetic inhibition of DR neurons decreased hyperalgesia during spontaneous heroin withdrawal in male and female C57/B6 mice. By neuroanatomy, we identified three major subtypes of DR neurons expressing μ-opioid receptors (MOR) that were activated in hyperalgesia during spontaneous withdrawal, those expressing vesicular GABA transporter (VGaT), glutamate transporter 3 (VGluT3), or co-expressing VGluT3 and tryptophan hydroxylase (TPH). In contrast, we identified a small population of DR-MOR neurons expressing solely TPH, which were not activated in hyperalgesia during spontaneous withdrawal. Collectively, these findings indicate a role of the DR in hyperalgesia during spontaneous heroin withdrawal mediated, in part, by the activation of local MOR-GABAergic, MOR-glutamatergic and MOR-co-releasing glutamatergic-serotonergic neurons. We found that specific chemogenetic inhibition of DR-VGaT neurons blocked hyperalgesia during spontaneous heroin withdrawal in male and female mice. Collectively, these findings indicate that DR-GABAergic neurons play a role in the expression of hyperalgesia during spontaneous heroin withdrawal.
Mehrad M, Dupont WD, Plummer WD Jr, Lewis JS Jr.
PMID: 29235037 | DOI: 10.1007/s12105-017-0874-2
The favorable features of high-risk human papillomavirus (HPV) in the head and neck are limited to those harboring transcriptionally-active HPV, which occur predominantly in the oropharynx (OP). Factors rendering the OP susceptible to HPV oncogenesis are largely unexplored. The role of cytokeratin 7 (CK7) in predisposition to HPV and cancer in the cervix has been evaluated. However, its significance in the H&N is unknown. CK7 immunohistochemistry was performed on a tissue microarray cohort of OP and non-oropharyngeal (NOP) squamous cell carcinomas (SCC) with known clinical follow-up and HPV E6/7 mRNA status. Expression was graded based on the distribution (1 ≤ 33%, 2 = 33-66%, 3 ≥ 66%) and intensity (1 = weak, 2 = strong) with combined score of ≥ 2 considered positive. Survival analysis was performed. Seventy-four NOPSCCs and 204 OPSCCs were studied. HPV was positive in 2.7% of NOPSCCs and 70.9% of OPSCCs. CK7 was positive in 23.0% of OPSCCs and 14.8% of NOPSCCs (p = 0.2), and in 24.1% of HPV positive versus 17.2% of negative patients (p = 0.2). There was no correlation with age, race, gender, HPV status, histologic type, tumor subsite, treatment, stage, or co-morbidities, and CK7 expression was not significantly associated with overall or disease specific survival. In our series, CK7 is positive in ~ 25% of H&N SCCs, although usually only focally. While CK7 has been suspected to be overexpressed selectively in HPV-related OPSCCs due to their origination from tonsillar crypt epithelium, we did not find any significant difference by anatomic H&N subsite, nor by HPV status, for its expression and found no association with patient survival.
