Wyeth MS, Pelkey KA, Yuan X, Vargish G, Johnston AD, Hunt S, Fang C, Abebe D, Mahadevan V, Fisahn A, Salter MW, McInnes RR, Chittajallu R, McBain CJ.
PMID: 28854365 | DOI: 10.1016/j.celrep.2017.08.017
Although Netos are considered auxiliary subunits critical for kainate receptor (KAR) function, direct evidence for their regulation of native KARs is limited. Because Neto KAR regulation is GluK subunit/Neto isoform specific, such regulation must be determined in cell-type-specific contexts. We demonstrate Neto1/2 expression in somatostatin (SOM)-, cholecystokinin/cannabinoid receptor 1 (CCK/CB1)-, and parvalbumin (PV)-containing interneurons. KAR-mediated excitation of these interneurons is contingent upon Neto1 because kainate yields comparable effects in Neto2 knockouts and wild-types but fails to excite interneurons or recruit inhibition in Neto1 knockouts. In contrast, presynaptic KARs in CCK/CB1 interneurons are dually regulated by both Neto1 and Neto2. Neto association promotes tonic presynaptic KAR activation, dampening CCK/CB1 interneuron output, and loss of this brake in Neto mutants profoundly increases CCK/CB1 interneuron-mediatedinhibition. Our results confirm that Neto1 regulates endogenous somatodendritic KARs in diverse interneurons and demonstrate Neto regulation of presynaptic KARs in mature inhibitory presynaptic terminals.
Smith, KM;Nguyen, E;Ross, SE;
PMID: 36464136 | DOI: 10.1016/j.jpain.2022.09.013
Opioid signaling has been shown to be critically important in the neuromodulation of sensory circuits in the superficial spinal cord. Agonists of the mu-opioid receptor (MOR) elicit itch, whereas agonists of the kappa-opioid receptor (KOR) have been shown to inhibit itch. Despite the clear roles of MOR and KOR for the modulation itch, whether the delta-opioid receptor (DOR) is involved in the regulation of itch remained unknown. Here, we show that intrathecal administration of DOR agonists suppresses chemical itch and that intrathecal application of DOR antagonists is sufficient to evoke itch. We identify that spinal enkephalin neurons co-express neuropeptide Y (NPY), a peptide previously implicated in the inhibition of itch. In the spinal cord, DOR overlapped with both the NPY receptor (NPY1R) and KOR, suggesting that DOR neurons represent a site for convergent itch information in the dorsal horn. Lastly, we found that neurons co-expressing DOR and KOR showed significant Fos induction following pruritogen-evoked itch. These results uncover a role for DOR in the modulation of itch in the superficial dorsal horn. Perspective: This article reveals the role of the delta-opioid receptor in itch. Intrathecal administration of delta agonists suppresses itch whereas the administration of delta antagonists is sufficient to induce itch. These studies highlight the importance of delta-opioid signaling for the modulation of itch behaviors, which may represent new targets for the management of itch disorders.
Cerebral cortex (New York, N.Y. : 1991)
Li, N;Li, N;Yang, L;Gu, H;Ji, J;Zhou, H;Zhu, Q;Yu, M;Sun, Y;Zhou, Y;
PMID: 35797708 | DOI: 10.1093/cercor/bhac230
Growth hormone secretagogue receptor 1a (GHSR1a)-the receptor for orexigenic hormone ghrelin-is a G protein-coupled receptor that is widely distributed in the brain, including the hippocampus. Studies have demonstrated that genetic deletion of GHSR1a affects memory, suggesting the importance of ghrelin/GHSR1a signaling in cognitive control. However, current reports are controversial, and the mechanism underlying GHSR1a modulation of memory is uncertain. Here, we first report that global GHSR1a knockout enhances hippocampus-dependent memory, facilitates initial LTP in dorsal hippocampal Schaffer Collateral-CA1 synapses, and downregulates Akt activity in the hippocampus. Moreover, we show that the intrinsic excitability of GAD67+ interneurons-rather than neighboring pyramidal neurons in the dCA1-is suppressed by GHSR1a deletion, an effect that is antagonized by acute application of the Akt activator SC79. In addition, the inhibitory postsynaptic currents (IPSCs) on dCA1 pyramidal neurons are selectively reduced in mice with a GHSR1a deficiency. Finally, we demonstrate that selectively increasing the excitability of parvalbumin-expressing interneurons by hM3Dq-DREADDs increases IPSCs on dCA1 pyramidal neurons and normalizes memory in Ghsr1a KO mice. Our findings thus reveal a novel mechanism underlying memory enhancement of GHSR1a deficiency and herein support an adverse effect of GHSR1a signaling in hippocampus-dependent memory processes.
Du, Y;
| DOI: 10.1136/thoraxjnl-2021-217650
The COVID-19 pandemic continues to be a worldwide threat and effective antiviral drugs and vaccines are being developed in a joint global effort. However, some elderly and immune-compromised populations are unable to raise an effective immune response against traditional vaccines.We hypothesised that passive immunity engineered by the in vivo expression of anti-SARS-CoV-2 monoclonal antibodies (mAbs), an approach termed vectored-immunoprophylaxis (VIP), could offer sustained protection against COVID-19 in all populations irrespective of their immune status or age.We developed three key reagents to evaluate VIP for SARS-CoV-2: (i) we engineered standard laboratory mice to express human ACE2 via rAAV9 in vivo gene transfer, to allow in vivo assessment of SARS-CoV-2 infection, (ii) to simplify in vivo challenge studies, we generated SARS-CoV-2 Spike protein pseudotyped lentiviral vectors as a simple mimic of authentic SARS-CoV-2 that could be used under standard laboratory containment conditions and (iii) we developed in vivo gene transfer vectors to express anti-SARS-CoV-2 mAbs.A single intranasal dose of rAAV9 or rSIV.F/HN vectors expressing anti-SARS-CoV-2 mAbs significantly reduced SARS-CoV-2 mimic infection in the lower respiratory tract of hACE2-expressing mice. If translated, the VIP approach could potentially offer a highly effective, long-term protection against COVID-19 for highly vulnerable populations; especially immune-deficient/senescent individuals, who fail to respond to conventional SARS-CoV-2 vaccines. The in vivo expression of multiple anti-SARS-CoV-2 mAbs could enhance protection and prevent rapid mutational escape.
Neuropathology : official journal of the Japanese Society of Neuropathology
Kuroda, N;Kawaji, H;Arai, Y;Otsuki, Y;Miura, K;Minato, H;Kuroda, K;Nakatogawa, H;Yamazoe, T;Tanaka, T;Inenaga, C;
PMID: 34933397 | DOI: 10.1111/neup.12762
Human papillomavirus (HPV)-related multiphenotypic sinonasal carcinoma (HMSC) is newly suggested and characterized by HPV-related tumors. HMSC has a relatively good prognosis. No cases of brain invasion have been reported to date. We encountered a case of brain invasion by HMSC, in which we assessed the effectiveness of radiotherapy in comparison with biopsy and autopsy. A 69-year-old man was referred to a hospital three months after intracerebral hemorrhage (ICH). Contrast magnetic resonance imaging revealed a tumor in the ethmoid sinus involving the brain. We performed transnasal biopsy and intensity-modulated radiotherapy for sinonasal and intracranial lesions. Despite radiotherapy, the patient died on day 41 after radiation. Biopsy specimens displayed mixed findings of epithelial and mesenchymal components. The tumor was immunoreactive for p16, and the RNA in situ hybridization for HPV was positive. Finally, we diagnosed the patient as having HMSC. Autopsy of the sinonasal tissue revealed a reduction in the number of tumor cells. There was a marked reduction in the number of tumor cells in the sinonasal tissue compared to that in the invaded brain tissue. The effectiveness of radiotherapy could depend on the histopathological components and location of the lesion, even in the same patient.
Henningfield, CM;Arreola, MA;Soni, N;Spangenberg, EE;Green, KN;
PMID: 34643971 | DOI: 10.1002/glia.24105
Previous studies suggest that microglial-expressed Apolipoprotein E (ApoE) is necessary to shift microglia into a neurodegenerative transcriptional state in Alzheimer's disease (AD) mouse models. On the other hand, elimination of microglia shifts amyloid beta (Aβ) accumulation from parenchymal plaques to cerebral amyloid angiopathy (CAA), mimicking the effects of global APOE*4 knock-in. Here, we specifically knock-out microglial-expressed ApoE while keeping astrocytic-expressed ApoE intact. When microglial-specific ApoE is knocked-out of a 5xFAD mouse model of AD, we found a ~35% increase in average Aβ plaque size, but no changes in plaque load, microglial number, microglial clustering around Aβ plaques, nor the formation of CAA. Immunostaining revealed ApoE protein present in plaque-associated microglia in 5xFAD mice with microglial-specific ApoE knockout, suggesting that microglia can take up ApoE from other cellular sources. Mice with Apoe knocked-out of microglia had lower synaptic protein levels than control mice, indicating that microglial-expressed ApoE may have a role in synapse maintenance. Surprisingly, microglial-specific ApoE knock-out resulted in few differentially expressed genes in both 5xFAD and control mice; however, some rescue of 5xFAD associated neuronal networks may occur with microglial-specific ApoE knock-out as shown by weighted gene co-expression analysis. Altogether, our data indicates that microglial-expressed ApoE may not be necessary for plaque formation or for the microglial transcriptional shift into a Disease Associated Microglia state that is associated with reactivity to plaques but may be necessary for plaque homeostasis in disease and synaptic maintenance under normal conditions.
Current opinion in pharmacology
Kumari, R;Ouyang, X;Wang, J;Xu, X;Zheng, M;An, X;Li, QX;
PMID: 34619442 | DOI: 10.1016/j.coph.2021.08.008
Chimeric antigen receptor (CAR) T cells have largely been successful in treating hematological malignancies in the clinic but have not been as effective in treating solid tumors, in part, owing to poor access and the immunosuppressive tumor microenvironment. In addition, CAR-T therapy can cause potentially life-threatening side effects, including cytokine release syndrome and neurotoxicity. Current preclinical testing of CAR-T therapy efficacy is typically performed in mouse tumor models, which often fails to predict toxicity. Recent developments in humanized models and transgenic mice as well as in vitro three-dimensional organoids in early development and nonhuman primate models are being adopted for CAR-T cell efficacy and toxicity assessment. However, because no single model perfectly recapitulates the human immune system and tumor microenvironment, careful model selection based on their respective pros and cons is crucial for adequate evaluation of different CAR-T treatments, so that their clinical development can be better supported.
Do papillomaviruses cause feline cutaneous squamous cell carcinoma?
Teh, A;Krockenberger, M;
| DOI: 10.18849/ve.v6i3.402
PICO question
In cats infected with papillomavirus, is the risk of developing feline cutaneous squamous cell carcinoma greater than cats that are not infected with papillomavirus?
Clinical bottom line
Category of research question
Risk
The number and type of study designs reviewed
Eleven papers were critically reviewed, nine were case-control studies and two were experimental in vitro studies
Strength of evidence
Moderate
Outcomes reported
Infection of feline epithelial skin cells with Felis catus papillomavirus type 2 (FcaPV-2) is a risk factor for the development of feline cutaneous squamous cell carcinoma. The pathogenesis of FcaPV-2 infection and neoplastic transformation into malignant cells shares similar pathways to the human papillomavirus (HPV) model of pathogenesis and carcinogenesis with some differences
Conclusion
In conclusion, there is moderate strength of evidence in the literature to support a role of FcaPV-2 in the development of cutaneous squamous cell carcinomas in cats. Therefore, prevention of infection with FcaPV-2 should prevent some cancers
How to apply this evidence in practice
The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources.
Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.
GATA3 maintains the quiescent state of cochlear supporting cells by regulating p27kip1
Xu, J;Yu, D;Dong, X;Xie, X;Xu, M;Guo, L;Huang, L;Tang, Q;Gan, L;
PMID: 34349220 | DOI: 10.1038/s41598-021-95427-3
Haplo-insufficiency of the GATA3 gene causes hypoparathyroidism, sensorineural hearing loss, and renal disease (HDR) syndrome. Previous studies have shown that Gata3 is required for the development of the prosensory domain and spiral ganglion neurons (SGNs) of the mouse cochlea during embryogenesis. However, its role in supporting cells (SCs) after cell fate specification is largely unknown. In this study, we used tamoxifen-inducible Sox2CreERT2 mice to delete Gata3 in SCs of the neonatal mouse cochlea and showed that loss of Gata3 resulted in the proliferation of SCs, including the inner pillar cells (IPCs), inner border cells (IBCs), and lateral greater epithelium ridge (GER). In addition, loss of Gata3 resulted in the down-regulation of p27kip1, a cell cycle inhibitor, in the SCs of Gata3-CKO neonatal cochleae. Chromatin immunoprecipitation analysis revealed that GATA3 directly binds to p27kip1 promoter and could maintain the quiescent state of cochlear SCs by regulating p27kip1 expression. Furthermore, RNA-seq analysis revealed that loss of Gata3 function resulted in the change in the expression of genes essential for the development and function of cochlear SCs, including Tectb, Cyp26b1, Slitrk6, Ano1, and Aqp4.
ZNRF3 and RNF43 cooperate to safeguard metabolic liver zonation and hepatocyte proliferation
Sun, T;Annunziato, S;Bergling, S;Sheng, C;Orsini, V;Forcella, P;Pikiolek, M;Kancherla, V;Holwerda, S;Imanci, D;Wu, F;Meylan, LC;Puehringer, LF;Waldt, A;Oertli, M;Schuierer, S;Terracciano, LM;Reinker, S;Ruffner, H;Bouwmeester, T;Sailer, AW;George, E;Roma, G;de Weck, A;Piscuoglio, S;Lohmann, F;Naumann, U;Liberali, P;Cong, F;Tchorz, JS;
PMID: 34129813 | DOI: 10.1016/j.stem.2021.05.013
AXIN2 and LGR5 mark intestinal stem cells (ISCs) that require WNT/β-Catenin signaling for constant homeostatic proliferation. In contrast, AXIN2/LGR5+ pericentral hepatocytes show low proliferation rates despite a WNT/β-Catenin activity gradient required for metabolic liver zonation. The mechanisms restricting proliferation in AXIN2+ hepatocytes and metabolic gene expression in AXIN2+ ISCs remained elusive. We now show that restricted chromatin accessibility in ISCs prevents the expression of β-Catenin-regulated metabolic enzymes, whereas fine-tuning of WNT/β-Catenin activity by ZNRF3 and RNF43 restricts proliferation in chromatin-permissive AXIN2+ hepatocytes, while preserving metabolic function. ZNRF3 deletion promotes hepatocyte proliferation, which in turn becomes limited by RNF43 upregulation. Concomitant deletion of RNF43 in ZNRF3 mutant mice results in metabolic reprogramming of periportal hepatocytes and induces clonal expansion in a subset of hepatocytes, ultimately promoting liver tumors. Together, ZNRF3 and RNF43 cooperate to safeguard liver homeostasis by spatially and temporally restricting WNT/β-Catenin activity, balancing metabolic function and hepatocyte proliferation.
Gut Innate Immunity and HIV Pathogenesis
Dillon, SM;Wilson, CC;
PMID: 33687703 | DOI: 10.1007/s11904-021-00544-3
In the gastro-intestinal tract, the complex network of multiple innate cell populations play critical roles not only as a first line of defense against invading pathogens and in driving adaptive immune responses but also in maintaining intestinal homeostasis. Here, we describe the roles of various innate immune cell populations in gut immunity and detail studies investigating the impact of acute and chronic HIV infection on these cell populations. Alterations in frequencies, phenotype and/or function of innate lymphoid cells, dendritic cells, macrophages, neutrophils, and innate-like T cells have been reported in people with HIV (PWH), with many of these features persisting despite anti-retroviral therapy and virological suppression. Dysregulated gut innate immunity in PWH is a feature of gut pathogenesis. A greater understanding of the mechanisms driving impairment in the multiple different gut innate immune cell populations and the downstream consequences of an altered innate immune response on host defense and gut homeostasis in PWH is needed to develop more effective HIV treatments and cure strategies.
The developing murine lung is susceptible to acetaminophen toxicity
American journal of physiology. Lung cellular and molecular physiology
Dobrinskikh, E;Sherlock, LG;Orlicky, D;Zheng, L;de Dios, R;Balasubramaniyan, D;Sizemore, T;Butler, B;Wright, CJ;
PMID: 33759579 | DOI: 10.1152/ajplung.00072.2021
Acetaminophen (N-acetyl-p-aminophenol, APAP) use in the neonatal intensive care unit is rapidly increasing. While APAP-related hepatotoxicity is rarely reported in the neonatal literature, other end-organ toxicity can occur with toxic exposures. APAP-induced lung injury has been reported with toxic exposures in adults, but whether this occurs in the developing lung is unknown. Therefore, we tested whether toxic APAP exposures would injure the developing lung. Neonatal C57BL/6 mice (PN7, early alveolar stage of lung development) were exposed to a dose of APAP known to cause hepatotoxicity in adult mice (280 mg/kg, IP). This exposure induced significant lung injury in the absence of identifiable hepatic toxicity. This injury was associated with increased pulmonary expression of Cyp2e1, the xenobiotic enzyme responsible for the toxic conversion of APAP. Exposure was associated with increased pulmonary expression of antioxidant response genes and decreased pulmonary glutathione peroxidase activity level. Furthermore, we observed an increase in pulmonary expression of pro-inflammatory cytokines and chemokines. Lastly, we were able to demonstrate that this toxic APAP exposure was associated with a shift in pulmonary metabolism away from glycolysis with an increased oxidative phosphorylation, a finding consistent with increased mitochondrial workload, potentially leading to mitochondrial toxicity. This previously unrecognized injury and metabolic implications highlight the need to look beyond the liver and evaluate both the acute and long-term pulmonary implications of APAP exposure in the perinatal period.