Preclinical translational platform of neuroinflammatory disease biology relevant to neurodegenerative disease.

Neuroinflammation is a key driver of neurodegenerative disease, however the tools available to model this disease biology at the systems level are lacking. We describe a translational drug discovery platform based on organotypic culture of murine cortical brain slices that recapitulate disease-relevant neuroinflammatory biology. After an acute injury response, the brain slices assume a chronic neuroinflammatory state marked by transcriptomic profiles indicative of activation of microglia and astrocytes and loss of neuronal function. Microglia are necessary for manifestation of this neuroinflammation, as depletion of microglia prior to isolation of the brain slices prevents both activation of astrocytes and robust loss of synaptic function genes. The transcriptomic pattern of neuroinflammation in the mouse platform is present in published datasets derived from patients with amyotrophic lateral sclerosis, Huntington's disease, and frontotemporal dementia. Pharmacological utility of the platform was validated by demonstrating reversal of microglial activation and the overall transcriptomic signature with transforming growth factor-ß. Additional anti-inflammatory targets were screened and inhibitors of glucocorticoid receptors, COX-2, dihydrofolate reductase, and NLRP3 inflammasome all failed to reverse the neuroinflammatory signature. Bioinformatics analysis of the neuroinflammatory signature identified protein tyrosine phosphatase non-receptor type 11 (PTPN11/SHP2) as a potential target. Three structurally distinct inhibitors of PTPN11 (RMC-4550, TN0155, IACS-13909) reversed the neuroinflammatory disease signature. Collectively, these results highlight the utility of this novel neuroinflammatory platform for facilitating identification and validation of targets for neuroinflammatory neurodegenerative disease drug discovery.

Findings from the development of a nursing joint professional practice model for the U.S. military.

BACKGROUND: By 2022 the Defense Health Agency became responsible for administration of all military treatment facilities (MTFs), which were previously managed by their respective military services. However, three different service-specific nursing professional practice models currently govern nursing practice in MTFs. PURPOSE: To describe the literature search, review, and synthesis of evidence which informed the JPPM and provide some of the most actionable findings. METHODS: A team of tri-service nurses developed the JPPM by conducting six rigorous systematic reviews to synthesize evidence pertaining to relevant model components. DISCUSSION: A total of 51,360 titles and abstracts were initially screened. Data were extracted from 540 included articles. The team then developed standards for five JPPM components: evidence-based practice, safety and quality, leadership development, healthy work environment, and operational readiness. CONCLUSION: The JPPM is a meaningful framework that will help create a mutual professional identity and shared vision to promote a unified nursing force in U.S. military settings.

Components, Implementation, and Outcomes of a Nursing Professional Practice Model: A Systematic Review.

Nursing professional practice models (PPMs) are known to have beneficial effects on nurse and patient outcomes. Determining what components should be present in a PPM, how to implement a PPM, and evaluating the outcomes associated with a PPM is less certain. Therefore, as part of a larger project to develop a nursing PPM for use within the United States Military Health System, this study aimed to conduct a systematic literature review on nursing PPMs. Specifically, the review sought to investigate components, implementation, and outcomes of PPMs in current literature. A total of 37 articles were included in the review. The literature supported the development of 12 recommendations for creating, implementing, and evaluating a nursing PPM. As health care facilities develop their own PPMs or reassess their current PPMs, findings from this review may assist hospital leadership by providing the most recent evidence on the strategic value of nursing PPMs in contemporary health care.

Working memory impairment in calcineurin knock-out mice is associated with alterations in synaptic vesicle cycling and disruption of high-frequency synaptic and network activity in prefrontal cortex.

Working memory is an essential component of higher cognitive function, and its impairment is a core symptom of multiple CNS disorders, including schizophrenia. Neuronal mechanisms supporting working memory under normal conditions have been described and include persistent, high-frequency activity of prefrontal cortical neurons. However, little is known about the molecular and cellular basis of working memory dysfunction in the context of neuropsychiatric disorders. To elucidate synaptic and neuronal mechanisms of working memory dysfunction, we have performed a comprehensive analysis of a mouse model of schizophrenia, the forebrain-specific calcineurin knock-out mouse. Biochemical analyses of cortical tissue from these mice revealed a pronounced hyperphosphorylation of synaptic vesicle cycling proteins known to be necessary for high-frequency synaptic transmission. Examination of the synaptic vesicle cycle in calcineurin-deficient neurons demonstrated an impairment of vesicle release enhancement during periods of intense stimulation. Moreover, brain slice and in vivo electrophysiological analyses showed that loss of calcineurin leads to a gene dose-dependent disruption of high-frequency synaptic transmission and network activity in the PFC, correlating with selective working memory impairment. Finally, we showed that levels of dynamin I, a key presynaptic protein and calcineurin substrate, are significantly reduced in prefrontal cortical samples from schizophrenia patients, extending the disease relevance of our findings. Our data provide support for a model in which impaired synaptic vesicle cycling represents a critical node for disease pathologies underlying the cognitive deficits in schizophrenia.

Discordance between cytologic results in multiple thyroid nodules within the same patient.

OBJECTIVE: To examine the frequency of discordant cytologic results between multiple thyroid nodules biopsied in the same patient. STUDY DESIGN: In a retrospective chart review of 441 consecutive patients, 326 (73.9%) had 2 or more nodules with colloid and/or thyroid cells recovered. Cytology was classified as (A) colloid only, (B) benign colloid nodule with or without degeneration, (C) Hashimoto's, or (D) follicular or Hürthle cell neoplasm, hyperplasia or suspicious for malignancy. Discordance was defined as having at least 2 different categories in the same patient. Twenty-four predetermined factors were analyzed, including demographics, laboratory values and ultrasound characteristics. RESULTS: The results, by category, were A, 164 (18.4%); B, 575 (64.6%); C, 131 (14.7%); and D, 20 (2.2%). Overall, 126 of 326 (38.7%) patients had at least 1 discordant grouping between their nodules. Of 326 patients, 165 had 2, 94 had 3, 48 had 4, 14 had 5, and 5 had 6 nodules biopsied, of which 48 (29.1%), 39 (41.5%), 29 (60.4%), 8 (57.1%) and 2 (40.0%), respectively, showed diagnostic discordances (p = 0.0007). CONCLUSION: The high rate (38.7%) of discordance between biopsies of multiple nodules in the same patient support a recommendation to biopsy all nodules that otherwise meet criteria for biopsy, as opposed to only the largest one.

The role of reelin in adult synaptic function and the genetic and epigenetic regulation of the reelin gene.

An emerging theme in the field of neuroscience is that processes critical for neurodevelopment have been co-opted by the adult nervous system to subserve synaptic plasticity and cognition. In this review, we highlight a surprising intersection of two developmental processes that together play a critical role in synaptic plasticity, memory formation and cognition. Reelin, a large glycoprotein associated with the extracellular matrix, is crucial for cortical and cerebellar development. Recent data from several groups indicate that reelin plays a unique modulatory role in the induction of synaptic plasticity in the hippocampus, and that normal levels of reelin in the adult brain are essential for successful formation of certain forms of long-term memory. Given that both increases and decreases in reelin expression have significant effects on plasticity and memory, regulation of reelin expression is predicted to have significant effects on neural function. Epigenetic regulation of transcription is critical for differentiation of cellular phenotype in metazoans. Dozens of reports in the last few years have demonstrated that epigenetics is involved in modulating gene expression in the adult nervous system and subserves plasticity and memory formation. We review a series of studies that demonstrate that the reelin promoter is subject to differential DNA methylation in the adult nervous system, and that perturbations in reelin promoter methylation correlate with alterations in memory formation and cognition. Thus, two distinct developmental processes, reelin-mediated signaling and epigenetic-based transcriptional regulation, appear to have synergized in the adult nervous system to create a sensitive and robust system for modulation of synaptic plasticity, and ultimately provide a powerful set of tools to probe the molecular basis of cognition.

c-Rel, an NF-kappaB family transcription factor, is required for hippocampal long-term synaptic plasticity and memory formation.

Transcription is a critical component for consolidation of long-term memory. However, relatively few transcriptional mechanisms have been identified for the regulation of gene expression in memory formation. In the current study, we investigated the activity of one specific member of the NF-kappaB transcription factor family, c-Rel, during memory consolidation. We found that contextual fear conditioning elicited a time-dependent increase in nuclear c-Rel levels in area CA1 and DG of hippocampus. These results suggest that c-rel is active in regulating transcription during memory consolidation. To identify the functional role of c-Rel in memory formation, we characterized c-rel(-/-) mice in several behavioral tasks. c-rel(-/-) mice displayed significant deficits in freezing behavior 24 h after training for contextual fear conditioning but showed normal freezing behavior in cued fear conditioning and in short-term contextual fear conditioning. In a novel object recognition test, wild-type littermate mice exhibited a significant preference for a novel object, but c-rel(-/-) mice did not. These results indicate that c-rel(-/-) mice have impaired hippocampus-dependent memory formation. To investigate the role of c-Rel in long-term synaptic plasticity, baseline synaptic transmission and long-term potentiation (LTP) at Schaffer collateral synapses in c-rel(-/-) mice was assessed. c-rel(-/-) slices had normal baseline synaptic transmission but exhibited significantly less LTP than did wild-type littermate slices. Together, our results demonstrate that c-Rel is necessary for long-term synaptic potentiation in vitro and hippocampus-dependent memory formation in vivo.

Astroglial nuclear factor-kappaB regulates learning and memory and synaptic plasticity in female mice.

Astrocytes play a pivotal role in regulating synaptic plasticity and synapse formation. The nuclear factor-kappa B (NF-kappaB) family of transcription factors has recently been demonstrated to be an important modulator of synaptic plasticity and learning/memory. In this study, we investigated the role of astroglial NF-kappaB in synaptic plasticity and learning/memory using transgenic mice over-expressing an N-terminal truncated form of inhibitor of NF-kappaB alpha (IkappaBalpha) in astrocytes (GFAP-IkappaBetaalpha-dn). We demonstrated that female transgenic mice, but not males, have robust deficits in hippocampal and extra-hippocampal-dependent learning and memory. We also determined that there are significant deficits in LTP and expression of metabotropic glutamate receptor 5 and post-synaptic density protein 95 (PSD95) in female transgenic mice. These findings indicate that astroglial NF-kappaB is an important regulator of learning/memory and synaptic plasticity.

Long-term potentiation and contextual fear conditioning increase neuronal glutamate uptake.

Induction and expression of long-term potentiation (LTP) in area CA1 of the hippocampus require the coordinated regulation of several cellular processes. We found that LTP in area CA1 was associated with an N-methyl-D-aspartate (NMDA) receptor-dependent increase in glutamate uptake. The increase in glutamate uptake was inhibited by either removal of Na+ or addition of D,L-threo-beta-hydroxyaspartate. Dihydrokainate (DHK), a specific inhibitor of the glial glutamate transporter GLT-1, did not block the increase in glutamate uptake. LTP was also associated with a translocation of the EAAC1 glutamate transporter from the cytosol to the plasma membrane. Contextual fear conditioning increased the maximum rate (Vmax) of glutamate uptake and membrane expression of EAAC1 in area CA1. These results indicate that regulation of glutamate uptake may be important for maintaining the level of synaptic strength during long-term changes in synaptic efficacy.

Alpha3-integrins are required for hippocampal long-term potentiation and working memory.

Integrins comprise a large family of heterodimeric, transmembrane cell adhesion receptors that mediate diverse neuronal functions in the developing and adult CNS. Recent pharmacological and genetic studies have suggested that beta1-integrins are critical in synaptic plasticity and memory formation. To further define the role of integrins in these processes, we generated a postnatal forebrain and excitatory neuron-specific knockout of alpha3-integrin, one of several binding partners for beta1 subunit. At hippocampal Schaffer collateral-CA1 synapses, deletion of alpha3-integrin resulted in impaired long-term potentiation (LTP). Basal synaptic transmission and paired-pulse facilitation were normal in the absence of alpha3-integrin. Behavioral studies demonstrated that the mutant mice were selectively defective in a hippocampus-dependent, nonmatch-to-place working memory task, but were normal in other hippocampus-dependent spatial tasks. The impairment in LTP and working memory is similar to that observed in beta1-integrin conditional knockout mice, suggesting that alpha3-integrin is the functional binding partner for beta1 for these processes in the forebrain.

Learning and memory and synaptic plasticity are impaired in a mouse model of Rett syndrome.

Loss-of-function mutations or abnormal expression of the X-linked gene encoding methyl CpG binding protein 2 (MeCP2) cause a spectrum of postnatal neurodevelopmental disorders including Rett syndrome (RTT), nonsyndromic mental retardation, learning disability, and autism. Mice expressing a truncated allele of Mecp2 (Mecp2(308)) reproduce the motor and social behavior abnormalities of RTT; however, it is not known whether learning deficits are present in these animals. We investigated learning and memory, neuronal morphology, and synaptic function in Mecp2(308) mice. Hippocampus-dependent spatial memory, contextual fear memory, and social memory were significantly impaired in Mecp2(308) mutant males (Mecp2(308/Y)). The morphology of dendritic arborizations, the biochemical composition of synaptosomes and postsynaptic densities, and brain-derived neurotrophic factor expression were not altered in these mice. However, reduced postsynaptic density cross-sectional length was identified in asymmetric synapses of area CA1 of the hippocampus. In the hippocampus of symptomatic Mecp2(308/Y) mice, Schaffer-collateral synapses exhibited enhanced basal synaptic transmission and decreased paired-pulse facilitation, suggesting that neurotransmitter release was enhanced. Schaffer-collateral long-term potentiation (LTP) was impaired. LTP was also reduced in the motor and sensory regions of the neocortex. Finally, very early symptomatic Mecp2(308/Y) mice had increased basal synaptic transmission and deficits in the induction of long-term depression. These data demonstrate a requirement for MeCP2 in learning and memory and suggest that functional and ultrastructural synaptic dysfunction is an early event in the pathogenesis of RTT.

Regulation of nuclear factor kappaB in the hippocampus by group I metabotropic glutamate receptors.

An increasing amount of evidence suggests that the family of nuclear factor kappaB (NF-kappaB) transcription factors plays an important role in synaptic plasticity and long-term memory formation. The present study investigated the regulation of NF-kappaB family members p50, p65/RelA, and c-Rel in the hippocampus in response to metabotropic glutamate receptor (mGluR) signaling. Activation of group I metabotropic glutamate receptors (GpI-mGluRs) with the agonist (S)-3,5-dihydroxyphenylglycine (DHPG) resulted in a time-dependent increase in DNA binding activity of p50, p65, and c-Rel in area CA1 of the hippocampus. An antagonist of mGluR5, 2-Methyl-6-(phenylethynyl)pyridine, inhibited the DHPG-induced activation of NF-kappaB, whereas an antagonist of mGluR1, (S)-(+)-alpha-amino-4-carboxy-2-methylbenzeneacetic acid, did not. Using a series of inhibitors, we investigated the signaling pathways necessary for DHPG-induced activation of NF-kappaB and found that they included the phosphatidyl inositol 3-kinase, protein kinase C, mitogen-activated protein kinase kinase, and p38-mitogen-activated protein kinase pathways. To determine the functional significance of mGluR-induced regulation of NF-kappaB, we measured long-term depression (LTD) of Schaffer-collateral synapses in the hippocampus of c-Rel knock-out mice. Early phase LTD was normal in c-rel(-/-) mice. However, late-phase LTD (>90 min) was impaired in c-rel(-/-) mice. The observations of this deficit in hippocampal synaptic plasticity prompted us to further investigate long-term memory formation in c-rel(-/-) mice. c-rel(-/-) mice exhibited impaired performance in a long-term passive avoidance task, providing additional evidence for c-Rel in long-term memory formation. These results demonstrate that the NF-kappaB transcription factor family is regulated by GpI-mGluRs in the hippocampus and that the c-Rel transcription factor is necessary for long-term maintenance of LTD and formation of long-term memory.

Assessment of Spontaneous Alternation, Novel Object Recognition and Limb Clasping in Transgenic Mouse Models of Amyloid-ß and Tau Neuropathology.

Here we describe a staged, behavioral testing approach that can be used to screen for compounds that exhibit in vivo efficacy on cognitive and functional motor behaviors in transgenic mouse models of ß-amyloidosis and tauopathy. The paradigm includes tests for spontaneous alternation in a Y-maze, novel object recognition, and limb clasping. These tests were selected because they: 1) interrogate function of cognitive or motor domains and the correlate neural circuitry relevant to the human disease state, 2) have clearly defined endpoints, 3) have easily implementable quality control checks, 4) can be run in a moderate throughput format, and 5) require little intervention by the investigator. These methods are designed for investigators looking to screen compounds for activity in short-term and working memory tasks, or functional motor behaviors associated with Alzheimer's disease mouse models. The methods described here use behavioral tests that engage a number of different brain regions including hippocampus and various cortical areas. Investigators that desire cognitive tests that specifically assess cognition mediated by a single brain region could use these techniques to supplement other behavioral tests.

NPT088 reduces both amyloid-ß and tau pathologies in transgenic mice.

INTRODUCTION: Alzheimer's disease (AD) is characterized by appearance of both extracellular senile plaques and intracellular neurofibrillary tangles, comprised of aggregates of misfolded amyloid-ß (Aß) and hyper-phosphorylated tau, respectively. In a previous study, we demonstrated that g3p, a capsid protein from bacteriophage M13, binds to and remodels misfolded aggregates of proteins that assume an amyloid conformation. We engineered a fusion protein ("NPT088") consisting of the active fragment of g3p and human-IgG1-Fc. METHODS: Aged Tg2576 mice or rTg4510 mice received NPT088 weekly via IP injection. Cognitive and/or functional motor endpoints were monitored during dosing. Pathology was quantified biochemically and immunohistochemically. RESULTS: NPT088-lowered Aß plaque and improved cognitive performance of aged Tg2576 mice. Moreover, NPT088 reduced phospho-tau pathology, reduced brain atrophy, and improved cognition in rTg4510 mice. DISCUSSION: These observations establish NPT088 as a novel therapeutic approach and potential drug class that targets both Aß and tau, the hallmark pathologies of AD.

Coregulation of glutamate uptake and long-term sensitization in Aplysia.

In Aplysia, long-term facilitation (LTF) at sensorimotor synapses of the pleural-pedal ganglia is mediated by an increase in the release of a neurotransmitter, which appears to be glutamate. Glutamate uptake also is increased in sensory neurons 24 hr after the induction of long-term sensitization (Levenson et al., 2000b). The present study investigated whether the same signaling pathways were involved in the long-term increase in glutamate uptake as in the induction of LTF. Thus, roles for cAMP, PKA (cAMP-dependent protein kinase), MAPK (mitogen-activated protein kinase), and tyrosine kinase in the regulation of glutamate uptake were tested. We found that 5-HT increased cAMP and activated PKA in sensory neurons. Exposure of pleural-pedal ganglia to analogs of cAMP or forskolin increased glutamate uptake 24 hr after treatments. Inhibitors of PKA (KT5720), MAPK (U0126 and PD98059), and tyrosine kinase (genistein) blocked the long-term increase in glutamate uptake produced by 5-HT. In addition, bpV, a tyrosine phosphatase inhibitor, facilitated the ability of subthreshold levels of 5-HT to increase glutamate uptake. Inhibition of PKC, which is not involved in LTF, had no effect on the long-term increase in glutamate uptake produced by 5-HT. Furthermore, activation of PKC by phorbol-12,13-dibutyrate did not produce long-term changes in glutamate uptake. The results demonstrate that the same constellation of second messengers and kinases is involved in the long-term regulation of both glutamate release and glutamate uptake. These similarities in signaling pathways suggest that regulation of glutamate release and uptake during formation of long-term memory are coordinated through coregulation of these two processes.

A bioinformatics analysis of memory consolidation reveals involvement of the transcription factor c-rel.

Consolidation of long-term memory (LTM) is a complex process requiring synthesis of new mRNAs and proteins. Many studies have characterized the requirement for de novo mRNA and protein synthesis; however, few studies have comprehensively identified genes regulated during LTM consolidation. We show that consolidation of long-term contextual memory in the hippocampus triggers altered expression of numerous genes encompassing many aspects of neuronal function. Like contextual memory formation, this altered gene expression required NMDA receptor activation and was specific for situations in which the animal formed an association between a physical context and a sensory stimulus. Using a bioinformatics approach, we found that regulatory elements for several transcription factors are over-represented in the upstream region of genes regulated during consolidation of LTM. Using a knock-out mouse, we found that c-rel, one of the transcription factors identified in our bioinformatics study, is necessary for hippocampus-dependent long-term memory formation.

Glutamate uptake in synaptic plasticity: from mollusc to mammal.

A great deal of research has been directed toward understanding the cellular mechanisms underlying synaptic plasticity and memory formation. To this point, most research has focused on the more "active" components of synaptic transmission: presynaptic transmitter release and postsynaptic transmitter receptors. Little work has been done characterizing the role neurotransmitter transporters might play during changes in synaptic efficacy. We review several new experiments that demonstrate glutamate transporters are regulated during changes in the efficacy of glutamatergic synapses. This regulation occurred during long-term facilitation of the sensorimotor synapse of Aplysia and long-term potentiation of the Schaffer-collateral synapse of the rat. We propose that glutamate transporters are "co-regulated" with other molecules/processes involved in synaptic plasticity, and that this process is phylogenetically conserved. These new findings indicate that glutamate transporters most likely play a more active role in neurotransmission than previously believed.