Regulation of the Ca2+ Channel CaV1.2 Supports Spatial Memory and Its Flexibility and LTD

Widespread release of norepinephrine (NE) throughout the forebrain fosters learning and memory via adrenergic receptor (AR) signaling, but the molecular mechanisms are largely unknown. The β2 AR and its downstream effectors, the trimeric stimulatory Gs-protein, adenylyl cyclase (AC), and the cAMP-dependent protein kinase A (PKA), form a unique signaling complex with the L-type Ca2+ channel (LTCC) CaV1.2. Phosphorylation of CaV1.2 by PKA on Ser1928 is required for the upregulation of Ca2+ influx on β2 AR stimulation and long-term potentiation induced by prolonged theta-tetanus (PTT-LTP) but not LTP induced by two 1-s-long 100-Hz tetani. However, the function of Ser1928 phosphorylation in vivo is unknown. Here, we show that S1928A knock-in (KI) mice of both sexes, which lack PTT-LTP, express deficiencies during initial consolidation of spatial memory. Especially striking is the effect of this mutation on cognitive flexibility as tested by reversal learning. Mechanistically, long-term depression (LTD) has been implicated in reversal learning. It is abrogated in male and female S1928A knock-in mice and by β2 AR antagonists and peptides that displace β2 AR from CaV1.2. This work identifies CaV1.2 as a critical molecular locus that regulates synaptic plasticity, spatial memory and its reversal, and LTD.SIGNIFICANCE STATEMENT We show that phosphorylation of the Ca2+ channel CaV1.2 on Ser1928 is important for consolidation of spatial memory and especially its reversal, and long-term depression (LTD). Identification of Ser1928 as critical for LTD and reversal learning supports the model that LTD underlies flexibility of reference memory.

Role of interventional radiology in pain management in oncology patients

This article reviews the current evidence of interventional radiology procedures for patients suffering with debilitating cancer pain, refractory to conventional therapies. Cancer pain is notoriously difficult to treat. Up to 90% of cancer patients experience pain with 56-82% of cancer pain controlled inadequately. Cancer pain influences a patient's ability to perform normal daily activities, causes higher risk of depression, and reduces quality of life. Pain-free status has been universally voted as a "good death". Alternative minimally invasive options include nerve blocks, neurolysis, bone ablation, spine and peripheral musculoskeletal augmentation techniques, embolisation, and cordotomy with evidence highlighting improved pain control, reduced analgesic requirements, and improved quality of life. Unfortunately, awareness and availability of these procedures is limited, potentially leaving patients suffering during their remaining life. The purpose of this review is to describe the basic concepts of interventional radiology techniques for pain palliation in oncology patients. In addition, emphasis will be given upon the need for an individually tailored approach aiming to augment efficacy and safety.

Exposure to DMSO during infancy alters neurochemistry, social interactions, and brain morphology in long-evans rats

INTRODUCTION

Dimethyl sulfoxide (DMSO) is a widely used solvent to dissolve hydrophobic substances for clinical uses and experimental in vivo purposes. While usually regarded safe, our prior studies suggest changes to behavior following DMSO exposure. We therefore evaluated the effects of a five-day, short-term exposure to DMSO on postnatal infant rats (P6-10).

METHODS

DMSO was intraperitoneally injected for five days at 0.2, 2.0, and 4.0 ml/kg body mass. One cohort of animals was sacrificed 24 hr after DMSO exposure to analyze the neurometabolic changes in four brain regions (cortex, hippocampus, basal ganglia, and cerebellum) by hydrophilic interaction liquid chromatography. A second cohort of animals was used to analyze chronic alterations to behavior and pathological changes to glia and neuronal cells later in life (P21-P40).

RESULTS

164 metabolites, including key regulatory molecules (retinoic acid, orotic acid, adrenic acid, and hypotaurine), were found significantly altered by DMSO exposure in at least one of the brain regions at P11 (p < .05). Behavioral tests showed significant hypoactive behavior and decreased social habits to the 2.0 and 4.0 ml DMSO/kg groups (p < .01). Significant increases in number of microglia and astrocytes at P40 were observed in the 4.0 ml DMSO/kg group (at p < .015.) CONCLUSIONS: Despite short-term exposure at low, putatively nontoxic concentrations, DMSO led to changes in behavior and social preferences, chronic alterations in glial cells, and changes in essential regulatory brain metabolites. The chronic neurological effects of DMSO exposure reported here raise concerns about its neurotoxicity and consequent safety in human medical applications and clinical trials.

Supportive Care: An Indispensable Component of Modern Oncology

The advent of new cancer therapies, alongside expected growth and ageing of the population, better survival rates and associated costs of care, is uncovering a need to more clearly define and integrate supportive care services across the whole spectrum of the disease. The current focus of cancer care is on initial diagnosis and treatment, and end of life care. The Multinational Association of Supportive Care in Cancer defines supportive care as 'the prevention and management of the adverse effects of cancer and its treatment'. This encompasses the entire cancer journey, and necessitates involvement and integration of most clinical specialties. Optimal supportive care can assist in accurate diagnosis and management, and ultimately improve outcomes. A national strategy to implement supportive care is needed to acknowledge evolving oncology practice, changing disease patterns and the changing patient demographic.

A phase Ib study of troriluzole (BHV-4157) in combination with nivolumab

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Background: The Metabotropic Glutamate Receptor 1 (GRM1) is overexpressed in many solid tumors. It activates MAPK and PI3K/AKT pathways and promotes an immune-suppressive tumor microenvironment. In an immunocompetent melanoma mouse model, GRM1 blockade using riluzole or its pro-drug troriluzole (BHV-4157) and PD-1 blockade inhibit tumor growth in an additive manner. We conducted a phase Ib trial of troriluzole and the PD-1 antibody nivolumab. Methods: Patients with advanced or refractory solid tumors were treated with increasing doses of troriluzole. Troriluzole monotherapy was given for a 14-day lead-in period and then patients received troriluzole in combination with nivolumab 240 mg IV every 2 weeks. Results: We enrolled 14 patients with advanced solid tumors (melanoma=3, NSCLC=3, renal cell cancer=2, NSCLC=2, head and neck cancer=2). Eleven patients had prior therapy with anti-PD-(L)1. PK sampling demonstrated that the prodrug was cleaved efficiently without regard to food (Table). The most common TEAEs (all grades) occurring in >40% of patients were transaminitis, increased lipase and nausea. DLT occurred in 3 patients: 1) grade 3 anorexia, 2) grade 3 fatigue and, 3) atrial fibrillation. The MTD was determined to be troriluzole 140 mg QAM + 280 mg PO QHS. The response rate was 7 % (1/14); this occurred in a PD-L1 treated patient. The 6-month PFS rate was 21%. Correlative studies will be presented. Conclusions: The combination of troriluzole and nivolumab was safe and well-tolerated in this highly PD-1 refractory population. Clinical trial information: NCT03229278. [Table: see text]

A phase I study to evaluate the safety of trigriluzole (BHV-4157) in combination with PD-1 blocking antibodies

TPS80

Background: The Metabotropic Glutamate Receptor 1 (GRM1) is expressed in 60-100% of human melanomas, breast cancers, and other solid tumors. Riluzole, an FDA-approved drug for ALS, inhibits GRM1 signal transduction. A phase 0 trial in melanoma patients demonstrated that riluzole suppressed signaling through the MAPK and PI3K/AKT pathways but no objective responses were seen in a phase 2 study.The clinical use of riluzole outside of ALS has been limited by: (i) poor oral bioavailability, (ii) extensive first-pass hepatic metabolism, (iii) high variability in PK parameters, (iv) food-related decrease in bioavailability, and (v) dose-related hepatotoxicity. Trigriluzole (BHV-4157) is a third generation prodrug of riluzole with improved PK/PD properties. In our MASS20 in vivo murine model of melanoma, GRM1 signal transduction appears to suppress tumor immunity through up-regulation of M-CSF and CCL2 expression with a subsequent increase in the percentage of M2 macrophages in the tumor microenvironment. In an immunocompetent mouse model, treatment with trigriluzole and anti-PD-1 antibody was more effective than either drug alone. Methods: Subjects with advanced or refractory solid cancers or lymphoma will be treated with increasing doses of trigriluzole in this phase 1b study. The dosing cohorts of trigriluzole will be using a semi-Bayesian modified toxicity probability interval dose escalation procedure. Trigriluzole monotherapy will be given for a 14-day lead in period and then patients will receive trigriluzole in combination with nivolumab 240mg IV every 2 weeks. After the maximum tolerated dose (MTD) of trigriluzole is identified, it will be checked in a cohort of 6 patients in combination with pembrolizumab. Total sample size will be 12 – 27 subjects. PD-1-directed therapy prior to entry is allowed. Blood samples and optional biopsies will be collected for correlative analysis. PBMCs and fresh tumor tissue will be grafted into NSG mice to create a patient-derived autologous double-humanized murine model for each participant. Clinical trial information: NCT03229278.

Abstract P3-13-01: Determining the breast tumor margin through genomics of the cancer-stromal interaction

This abstract was withdrawn by the authors.

Tollip SNP rs5743899 modulates human airway epithelial responses to rhinovirus infection

BACKGROUND

Rhinovirus (RV) infection in asthma induces varying degrees of airway inflammation (e.g. neutrophils), but the underlying mechanisms remain unclear.

OBJECTIVE

The major goal was to determine the role of genetic variation [e.g. single nucleotide polymorphisms (SNPs)] of Toll-interacting protein (Tollip) in airway epithelial responses to RV in a type 2 cytokine milieu.

METHODS

DNA from blood of asthmatic and normal subjects was genotyped for Tollip SNP rs5743899 AA, AG and GG genotypes. Human tracheobronchial epithelial (HTBE) cells from donors without lung disease were cultured to determine pro-inflammatory and antiviral responses to IL-13 and RV16. Tollip knockout and wild-type mice were challenged with house dust mite (HDM) and infected with RV1B to determine lung inflammation and antiviral response.

RESULTS

Asthmatic subjects carrying the AG or GG genotype (AG/GG) compared with the AA genotype demonstrated greater airflow limitation. HTBE cells with AG/GG expressed less Tollip. Upon IL-13 and RV16 treatment, cells with AG/GG (vs. AA) produced more IL-8 and expressed less antiviral genes, which was coupled with increased NF-κB activity and decreased expression of LC3, a hallmark of the autophagic pathway. Tollip co-localized and interacted with LC3. Inhibition of autophagy decreased antiviral genes in IL-13- and RV16-treated cells. Upon HDM and RV1B, Tollip knockout (vs. wild-type) mice demonstrated higher levels of lung neutrophilic inflammation and viral load, but lower levels of antiviral gene expression.

CONCLUSIONS AND CLINICAL RELEVANCE

Our data suggest that Tollip SNP rs5743899 may predict varying airway response to RV infection in asthma.

Abstract P5-04-09: Redefining the breast tumor margin through genomics of the tumor-stromal interaction

Objectives: Emerging data suggest that breast tumors enact gene expression changes in the surrounding stroma, facilitating future recurrence, cancer progression/invasion, metastasis, and altering therapeutic response. The extent to which this alteration penetrates the surrounding breast tissue has not been characterized. It is important to understand both the genomics of the tumor and the tissue that remains following surgery. This relationship could ultimately impact treatment decisions for effective surgery and adjuvant therapy based on the biological impact of the tumor on its anatomical surroundings.Methods: 32 patients undergoing mastectomy for invasive cancer from 2009-2012, had 9 tissue samples placed in RNA later: tumor, and stroma every 5 mm to 20 mm in two directions. A pathologist verified that the stroma was devoid of cancer cells. 108 tissues were analyzed for genome-wide mRNA expression by Affymetrix U133A 2+ arrays: 27 tumor, 29 5mm, 21 10mm, 11 15mm, and 20 20mm regions. RNA was purified by RNeasy chromatography (Qiagen) and assayed for integrity and concentration by Agilent Bioanalysis. SVM, ANOVA and PCA were performed to establish gene expression patterns, clustering and FDR in all tumor sets.Results We propose a gene expression profile/ map of the impact of the breast tumor on non-cancer stromal tissue in the breast. SVM analysis showed paired gene significance based on stromal proximity at all distances, which decreased in similarity with radial distance (closer stromal tissue to tumor had fewer differentially expressed genes). Analysis of gene expression patterns, PCA, unsupervised and supervised clustering demonstrate that the 5 mm region are significantly related to tumor gene expression profiles in almost all of the patients.In contrast, stromal tissue at 10mm, 15mm, and 20mm from the tumor-free margin display gene expression profiles that are similar to each other.But, with reduced similarity to tumor and 5mm. In a small number of patients, stroma at 10-15mm also displayed gene expression profiles significantly consistent with a tumor-like signature. Further analysis for the highest ranked 300 transcripts with the lowest FDR scores based on ANOVA are fully shared by the tumor and 5mm regions in over 30% the patients. A genomic signature is emerging that occurs in the stroma in both the tumor like and non-tumor like regions. Conclusion: These results show that breast tissue devoid of tumor cells is genomically highly related to the tumor at the 5mm, and even from regions 10, 15, and 20mm beyond cancer-free margins in some patients,, corresponding to regions considered histologically “normal”. We suggest that in a subset of patients, cancer-free stromal tissue is highly similar to the tumor. This implicates tumor imprinting as a means of genetically altering stromal tissues in a manner that is consistent with a potential for increased recurrence and de novo cancer development. In order to improve the effectiveness of breast cancer therapy, further determination of tumor/stromal interaction (determining optimal disease free tissue based on genomics and tumor promoting tissue), could directly impact both surgical and disease outcomes.Fig 1. Heatmap-Gene Expression in tumor&5mm are similar, but different from 10, 15, 20.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-04-09.

Voltage-gated calcium channel antagonists and traumatic brain injury

Traumatic brain injury (TBI) is a leading cause of death and disability in the United States. Despite more than 30 years of research, no pharmacological agents have been identified that improve neurological function following TBI. However, several lines of research described in this review provide support for further development of voltage gated calcium channel (VGCC) antagonists as potential therapeutic agents. Following TBI, neurons and astrocytes experience a rapid and sometimes enduring increase in intracellular calcium ([Ca²⁺]_i). These fluxes in [Ca²⁺]_i drive not only apoptotic and necrotic cell death, but also can lead to long-term cell dysfunction in surviving cells. In a limited number of in vitro experiments, both L-type and N-type VGCC antagonists successfully reduced calcium loads as well as neuronal and astrocytic cell death following mechanical injury. In rodent models of TBI, administration of VGCC antagonists reduced cell death and improved cognitive function. It is clear that there is a critical need to find effective therapeutics and rational drug delivery strategies for the management and treatment of TBI, and we believe that further investigation of VGCC antagonists should be pursued before ruling out the possibility of successful translation to the clinic.

Circulating irisin levels and coronary heart disease: association with future acute coronary syndrome and major adverse cardiovascular events

INTRODUCTION

Irisin is a newly discovered myokine, associated with 'browning' of the white adipose tissue, obesity, insulin resistance and metabolic syndrome. The purpose of this study is to evaluate circulating irisin as a predictor of acute coronary syndromes (ACSs) and major adverse cardiovascular events (MACE).

METHODS

Sub-study 1: a case-control study, nested within the Veteran's Affairs Normative Ageing Study, evaluating circulating irisin levels in 88 ACS cases and 158 age- and sampling year-matched controls, as a predictor of ACS. Sub-study 2: a prospective cohort study, where 103 participants with established coronary artery disease were stratified by circulating irisin levels at the time they received percutaneous coronary interventions (PCIs) and were followed for the development of MACE.

RESULTS

Study 1: there was no association between irisin levels and ACS in otherwise healthy individuals (odds ratio: 1.00 95% confidence interval: (0.99-1.00)). Study 2: the incidence of MACE was significantly lower in the first irisin tertile compared with the second and third (incidence rate 0 vs 0.92 (0.51-1.61) vs 0.57 (0.28-1.14) events per 1000 person-days; P < 0.01). This was primarily driven by the lower incidence of unstable angina (incidence rate 0 vs 0.61 (0.31-1.22) vs 0.43 (0.19-0.96) per 1000 person-days; P = 0.01).

CONCLUSION

This is the first study to date that demonstrates that, although circulating irisin levels do not predict the development of ACS in healthy individuals, increased irisin levels are associated with the development of MACE in patients with established coronary artery disease after PCI.

Alzheimer's disease therapeutic trials: EU/US Task Force report on recruitment, retention, and methodology

While we may not be able to find a cure for Alzheimer's disease (AD) in the near future, several drugs presently in trials have shown promise as possible modifiers of disease progression. However, we may not be able to demonstrate efficacy due to issues of recruitment, retention, site-to-site variability, and other methodological issues. It is thus incumbent on the scientific community to find solutions to these problems, particularly as the field moves toward preventing illness or treating the disease in its prodromal stages, where these methodological issues will become even more critical. We need to better understand why participants agree or refuse to enter drug trials, and why both primary care physicians and Alzheimer's specialists agree or refuse to involve their patients. We also need to quantify the impact of requiring imaging studies, extensive questionnaires, cognitive testing, and lumbar punctures on recruitment and retention. With these concerns in mind, an international task force meeting of experts from academia and industry in the United States, European Union, and Japan in San Diego, California on November 2, 2011 to focus on recruitment, retention and other methodological issues related to clinical trials for AD. Based on the recommendations of this Task force meeting, this Perspectives article critically reflects on the most critical and timely methodological issues related to recruitment and retention in prevention and therapeutic trials in AD, which are paralleled by a paradigm shift in the diagnostic conceptualization of this disease, as reflected by recently new proposed diagnostic criteria involving preclinical stages of the disease.

Resting functional connectivity between the hemispheres in childhood absence epilepsy

OBJECTIVE

The fundamental mechanisms by which childhood absence epilepsy (CAE) changes neural networks even between seizures remain poorly understood. During seizures, cortical and subcortical networks exhibit bihemspheric synchronous activity based on prior EEG-fMRI studies. Our aim was to investigate whether this abnormal bisynchrony may extend to the interictal period, using a blood oxygen level-dependent (BOLD) resting functional connectivity approach.

METHODS

EEG-fMRI data were recorded from 16 patients with CAE and 16 age- and gender-matched controls. Three analyses were performed. 1) Using 16 pairs of seizure-related regions of interest (ROI), we compared the between-hemisphere interictal resting functional connectivity of patients and controls. 2) For regions showing significantly increased interhemispheric connectivity in CAE, we then calculated connectivity to the entire brain. 3) A paired-voxel approach was performed to calculate resting functional connectivity between hemispheres without the constraint of predefined ROIs.

RESULTS

We found significantly increased resting functional connectivity between hemispheres in the lateral orbitofrontal cortex of patients with CAE compared to normal controls. Enhanced between-hemisphere connectivity localized to the lateral orbitofrontal cortex was confirmed by all 3 analysis methods.

CONCLUSIONS

Our results demonstrate abnormal increased connectivity between the hemispheres in patients with CAE in seizure-related regions, even when seizures were not occurring. These findings suggest that the lateral orbitofrontal cortex may play an important role in CAE pathophysiology, warranting further investigation. In addition, resting functional connectivity analysis may provide a promising biomarker to improve our understanding of altered brain function in CAE during the interictal period.