Identifying novel members of the Wntless interactome through genetic and candidate gene approaches

Wnt signaling is involved in crotalphine-induced analgesia in a rat model of neuropathic pain

The aberrant activation of Wnt/β-catenin and atypical Wnt/Ryk signaling pathways in the spinal cord is critical for the development and maintenance of neuropathic pain. Crotalphine is a structural analog to a peptide first identified in Crotalus durissus terrificus snake venom, which induces antinociception by activating kappa-opioid and CB2 cannabinoid receptors. Consistent with previous data, we showed that the protein levels of the canonical Wnt/β-catenin and the atypical Wnt/Ryk signaling pathways are increased in neuropathic rats. Importantly, the administration of crotalphine downregulates these protein levels, including its downstream cascades, such as TCF4 from the canonical pathway and NR2B glutamatergic receptor and Ca2+-dependent signals, via the Ryk receptor. The CB2 receptor antagonist, AM630, abolished the crotalphine-induced atypical Wnt/Ryk signaling pathway activation. However, the selective CB2 agonist affects both canonical and non-canonical Wnt signaling in the spinal cord. Next, we showed that crotalphine blocked hypersensitivity and significantly decreased the concentration of IL-1ɑ, IL-1β, IL-6, IL-10, IL-18, TNF-ɑ, MIP-1ɑ and MIP-2 induced by intrathecal injection of exogenous Wnt-3a agonist. Taken together, our findings show that crotalphine induces analgesia in a neuropathic pain model by down-regulating the canonical Wnt/β-catenin and the atypical Wnt/Ryk signaling pathways and, consequently controlling neuroinflammation. This effect is, at least in part, mediated by CB2 receptor activation. These results open a perspective for new approaches that can be used to target Wnt signaling in the context of chronic pain. PERSPECTIVE: Our work identified that crotalphine-induced activation of CB2 receptors plays a critical role in the impairment of Wnt signaling during neuropathic pain. This work suggests that drugs with opioid/cannabinoid activity may be a useful strategy to target Wnt signaling in the context of chronic pain.

The role of Evi/Wntless in exporting Wnt proteins

Intercellular communication by Wnt proteins governs many essential processes during development, tissue homeostasis and disease in all metazoans. Many context-dependent effects are initiated in the Wnt-producing cells and depend on the export of lipidated Wnt proteins. Although much focus has been on understanding intracellular Wnt signal transduction, the cellular machinery responsible for Wnt secretion became better understood only recently. After lipid modification by the acyl-transferase Porcupine, Wnt proteins bind their dedicated cargo protein Evi/Wntless for transport and secretion. Evi/Wntless and Porcupine are conserved transmembrane proteins, and their 3D structures were recently determined. In this Review, we summarise studies and structural data highlighting how Wnts are transported from the ER to the plasma membrane, and the role of SNX3-retromer during the recycling of its cargo receptor Evi/Wntless. We also describe the regulation of Wnt export through a post-translational mechanism and review the importance of Wnt secretion for organ development and cancer, and as a future biomarker.

Patterns of Cannabis- and Substance-Related Congenital General Anomalies in Europe: A Geospatiotemporal and Causal Inferential Study

INTRODUCTION

Recent series of congenital anomaly (CA) rates (CARs) have showed the close and epidemiologically causal relationship of cannabis exposure to many CARs. We investigated these trends in Europe where similar trends have occurred.

METHODS

CARs from EUROCAT. Drug use from European Monitoring Centre for Drugs and Drug Addiction. Income data from World Bank.

RESULTS

CARs were higher in countries with increasing daily use overall (p = 9.99 × 10^-14, minimum E-value (mEV) = 2.09) and especially for maternal infections, situs inversus, teratogenic syndromes and VACTERL syndrome (p = 1.49 × 10^-15, mEV = 3.04). In inverse probability weighted panel regression models the series of anomalies: all anomalies, VACTERL, foetal alcohol syndrome, situs inversus (SI), lateralization (L), and teratogenic syndromes (TS; AAVFASSILTS) had cannabis metric p-values from: p < 2.2 × 10^-16, 1.52 × 10^-12, 1.44 × 10^-13, 1.88 × 10^-7, 7.39 × 10^-6 and <2.2 × 10^-16. In a series of spatiotemporal models this anomaly series had cannabis metric p-values from: 8.96 × 10^-6, 6.56 × 10^-6, 0.0004, 0.0019, 0.0006, 5.65 × 10^-5. Considering E-values, the cannabis effect size order was VACTERL > situs inversus > teratogenic syndromes > FAS > lateralization syndromes > all anomalies. 50/64 (78.1%) E-value estimates and 42/64 (65.6%) mEVs > 9. Daily cannabis use was the strongest predictor for all anomalies.

CONCLUSION

Data confirmed laboratory, preclinical and recent epidemiological studies from Canada, Australia, Hawaii, Colorado and USA for teratological links between cannabis exposure and AAVFASSILTS anomalies, fulfilled epidemiological criteria for causality and underscored importance of cannabis teratogenicity. VACTERL data are consistent with causation via cannabis-induced Sonic Hedgehog inhibition. TS data suggest cannabinoid contribution. SI&L data are consistent with results for cardiovascular CAs. Overall, these data show that cannabis is linked across space and time and in a manner which fulfills epidemiological criteria for causality not only with many CAs, but with several multiorgan teratologic syndromes. The major clinical implication of these results is that access to cannabinoids should be tightly restricted in the interests of safeguarding the community's genetic heritage to protect and preserve coming generations, as is done for all other major genotoxins.

European Epidemiological Patterns of Cannabis- and Substance-Related Congenital Neurological Anomalies: Geospatiotemporal and Causal Inferential Study

Introduction. Of the many congenital anomalies (CAs) recently linked with community cannabis exposure, arguably the most concerning are neurological CAs (NCAs). We therefore conducted a detailed study of this in fourteen European nations. Methods. Congenital anomaly data were from Eurocat. Drug exposure data were from European Monitoring Centre for Drugs and Drug Addiction. Income from World bank. Results. The Netherlands, Spain, France and Bulgaria reported increasing rates of many NCAs. The NCA rate (NCAR) was higher in nations with increasing daily cannabis use when compared to those without (p = 0.0204, minimum E-value (mEV) = 1.35). At bivariate analysis, the mEVs of the following NCAs were significantly cannabis related: severe microcephaly 2.14 × 1013, craniosynostosis 5.27 × 1011, nervous system 4.87 × 1011, eye 2.73 × 107, microphthalmos 4.07 × 106, anencephalus 710.37, hydrocephalus 245.64, spina bifida 14.86 and neural tube defects 13.15. At inverse probability, weighted panel regression terms including cannabis were significantly related to the following series of anomalies: nervous system, anencephalus, severe microcephalus, microphthalmos, neural tube defect and spina bifida from p = 5.09 × 10−8, <2.2 × 10−16, <2.2 × 10−16, 4.84 × 10−11, <2.2 × 10−16 and 9.69 × 10−7. At geospatial regression, this same series of anomalies had terms including cannabis significant from p = 0.0027, 1.53 × 10−7, 3.65 × 10−6, 2.13 × 10−8, 0.0002 and 9.76 × 10−12. 88.0% of 50 E-value estimates and 72.0% of mEVs > 9. This analysis therefore demonstrates both close association of cannabis exposure with multiple NCAs across space-time and also fulfills the quantitative criteria of causal inferential analysis. Conclusions. Nine NCARs on bivariate and six NCARs on multivariable regression were cannabis related and fulfilled quantitative epidemiological criteria for causality and are consistent with other series. Particular concerns relate to exponential dose−response effects demonstrated in the laboratory and epidemiological studies. Great caution with community cannabinoid penetration is warranted. Data indicate that cannabis is a significant environmental teratogen and thus imply that cannabinoids should be regulated similarly to the manner in which all other important genotoxins are carefully controlled by communities for their self-sustaining longevity and the protection of generations yet to come.

European Epidemiological Patterns of Cannabis- and Substance-Related Body Wall Congenital Anomalies: Geospatiotemporal and Causal Inferential Study

As body wall congenital anomalies (BWCAs) have a long history of being associated with prenatal or community cannabis exposure (CCE), it was of interest to investigate these epidemiological relationships in Europe given the recent increases in cannabis use prevalence, daily intensity, and Δ9-tetrahydrocannabinol (THC) potency. Methods: This study makes use of BWCA data from Eurocat, drug exposure data from the European Monitoring Centre for Drugs and Drug Addiction, and income from the World Bank. Results: The mapping analysis showed that BWCARs increased in France, Spain, and the Netherlands. The bivariate mapping analysis showed that the BWCA rates (BWCAR) and the cannabis resin THC concentration rose simultaneously in France, the Netherlands, Bulgaria, Sweden, and Norway. The bivariate ranking of the BWCARs by median minimum E-value (mEV) was omphalocele > diaphragmatic hernia > abdominal wall defects > gastroschisis. With inverse probability weighted multivariable panel regression, the series of BWCAs, including gastroschisis, omphalocele, and diaphragmatic hernia, was positively related to various metrics of cannabis use from p = 2.45 × 10−14, 4.77 × 10−7 and <2.2 × 10−16. With geospatial regression, the same series of BWCAs was related to cannabis metrics from p = 0.0016, 5.28 × 10−6 and 4.88 × 10−9. Seventeen out of twenty-eight (60.7%) of the E-value estimates were >9 (high range), as were 14/28 (50.0%) of the mEVs. Conclusion: The data confirm the close relationship of the BWCARs with the metrics of CCE, fulfill the quantitative criteria of causal inference, and underscore the salience of the public health impacts of cannabinoid teratogenicity. Of major concern is the rising CCE impacting exponential cannabinoid genotoxic dose-response relationships. CCE should be carefully restricted to protect the food chain, the genome, and the epigenome of coming generations.

Geotemporospatial and causal inferential epidemiological overview and survey of USA cannabis, cannabidiol and cannabinoid genotoxicity expressed in cancer incidence 2003-2017: part 2 - categorical bivariate analysis and attributable fractions

BACKGROUND

As the cannabis-cancer relationship remains an important open question epidemiological investigation is warranted to calculate key metrics including Rate Ratios (RR), Attributable Fractions in the Exposed (AFE) and Population Attributable Risks (PAR) to directly compare the implicated case burden between emerging cannabinoids and the established carcinogen tobacco.

METHODS

SEER*Stat software from Centres for Disease Control was used to access age-standardized state census incidence of 28 cancer types (including "All (non-skin) Cancer") from National Cancer Institute in US states 2001-2017. Drug exposures taken from the National Survey of Drug Use and Health 2003-2017, response rate 74.1%. Federal seizure data provided cannabinoid exposure. US Census Bureau furnished income and ethnicity. Exposure dichotomized as highest v. lowest exposure quintiles. Data processed in R.

RESULTS

Nineteen thousand eight hundred seventy-seven age-standardized cancer rates were returned. Based on these rates and state populations this equated to 51,623,922 cancer cases over an aggregated population 2003-2017 of 124,896,418,350. Fifteen cancers displayed elevated E-Values in the highest compared to the lowest quintiles of cannabidiol exposure, namely (in order): prostate, melanoma, Kaposi sarcoma, ovarian, bladder, colorectal, stomach, Hodgkins, esophagus, Non-Hodgkins lymphoma, All cancer, brain, lung, CLL and breast. Eleven cancers were elevated in the highest THC exposure quintile: melanoma, thyroid, liver, AML, ALL, pancreas, myeloma, CML, breast, oropharynx and stomach. Twelve cancers were elevated in the highest tobacco quintile confirming extant knowledge and study methodology. For cannabidiol RR declined from 1.397 (95%C.I. 1.392, 1.402), AFE declined from 28.40% (28.14, 28.66%), PAR declined from 15.3% (15.1, 15.5%) and minimum E-Values declined from 2.13. For THC RR declined from 2.166 (95%C.I. 2.153, 2.180), AFE declined from 53.8% (53.5, 54.1%); PAR declined from 36.1% (35.9, 36.4%) and minimum E-Values declined from 3.72. For tobacco, THC and cannabidiol based on AFE this implies an excess of 93,860, 91,677 and 48,510 cases; based on PAR data imply an excess of 36,450, 55,780 and 14,819 cases.

CONCLUSION

Data implicate 23/28 cancers as being linked with THC or cannabidiol exposure with epidemiologically-causal relationships comparable to those for tobacco. AFE-attributable cases for cannabinoids (91,677 and 48,510) compare with PAR-attributable cases for tobacco (36,450). Cannabinoids constitute an important multivalent community carcinogen.

Geotemporospatial and causal inference epidemiological analysis of US survey and overview of cannabis, cannabidiol and cannabinoid genotoxicity in relation to congenital anomalies 2001–2015

Background

Cannabinoids including cannabidiol have recognized genotoxic activities but their significance has not been studied broadly epidemiologically across the teratological spectrum. We examined these issues including contextual space-time relationships and formal causal inferential analysis in USA.

Methods

State congenital anomaly (CA) rate (CAR) data was taken from the annual reports of the National Birth Defects Prevention Network 2001–2005 to 2011–2015. Substance abuse rates were from the National Survey of Drug Use and Health a nationally representative longitudinal survey of the non-institutionalized US population with 74.1% response rate. Drugs examined were cigarettes, monthly and binge alcohol, monthly cannabis and analgesic and cocaine abuse. Early termination of pregnancy for abortion (ETOPFA) rates were taken from the published literature. Cannabinoid concentrations were from Drug Enforcement Agency. Ethnicity and income data were from the US Census Bureau. Inverse probability weighted (IPW) regressions and geotemporospatial regressions conducted for selected CAs.

Results

Data on 18,328,529 births from an aggregated population of 2,377,483,589 for mid-year analyses 2005–2013 comprehending 12,611 CARs for 62 CAs was assembled and ETOPFA-corrected (ETOPFACAR) where appropriate. E-Values for ETOPFACARs by substance trends were elevated for THC (40 CAs), cannabis (35 CAs), tobacco (11 CAs), cannabidiol (8 CAs), monthly alcohol (5 CAs) and binge alcohol (2 CAs) with minimum E-Values descending from 16.55, 1.55x107, 555.10, 7.53x1019, 9.30 and 32.98. Cardiovascular, gastrointestinal, chromosomal, limb reductions, urinary, face and body wall CAs particularly affected. Highest v. lowest substance use quintile CAR prevalence ratios 2.84 (95%C.I. 2.44, 3.31), 4.85 (4.08, 5.77) and 1.92 (1.63, 2.27) and attributable fraction in exposed 0.28 (0.27, 0.28), 0.57 (0.51, 0.62) and 0.47 (0.38, 0.55) for tobacco, cannabis and cannabidiol. Small intestinal stenosis or atresia and obstructive genitourinary defect were studied in detail in lagged IPW pseudo-randomized causal regressions and spatiotemporal models confirmed the causal role of cannabinoids. Spatiotemporal predictive modelling demonstrated strongly sigmoidal non-linear cannabidiol dose-response power-function relationships (P = 2.83x10−60 and 1.61x10−71 respectively).

Conclusions

Data implicate cannabinoids including cannabidiol in a diverse spectrum of heritable CAs. Sigmoidal non-linear dose-response relationships are of grave concern.

These transgenerational genotoxic, epigenotoxic, chromosomal-toxic putatively causal teratogenic effects strongly indicate tight restrictions on community cannabinoid penetration.

SGIP1α, but Not SGIP1, is an Ortholog of FCHo Proteins and Functions as an Endocytic Regulator

Src homology 3-domain growth factor receptor-bound 2-like interacting protein 1 (SGIP1), originally known as a regulator of energy homeostasis, was later found to be an ortholog of Fer/Cip4 homology domain-only (FCHo) proteins and to function during endocytosis. SGIP1α is a longer splicing variant in mouse brains that contains additional regions in the membrane phospholipid-binding domain (MP) and C-terminal region, but functional consequences with or without additional regions between SGIP1 and SGIP1α remain elusive. Moreover, many previous studies have either inadvertently used SGIP1 instead of SGIP1α or used the different isoforms with or without additional regions indiscriminately, resulting in further confusion. Here, we report that the additional region in the MP is essential for SGIP1α to deform membrane into tubules and for homo-oligomerization, and SGIP1, which lacks this region, fails to perform these functions. Moreover, only SGIP1α rescued endocytic defects caused by FCHo knock-down. Thus, our results indicate that SGIP1α, but not SGIP1, is the functional ortholog of FCHos, and SGIP1 and SGIP1α are not functionally redundant. These findings suggest that caution should be taken in interpreting the role of SGIP1 in endocytosis.

Effects of cannabis on congenital limb anomalies in 14 European nations: A geospatiotemporal and causal inferential study

Cannabinoid exposure is increasing in some European nations. Europe therefore provides an interesting test environment for the recently reported link between cannabis exposure and congenital limb anomaly (CLA) rates (CLARs). Exponential genotoxic dose-response relationships make this investigation both intriguing and imperative. Annual CLAR in 14 nations were from Epidemiological Surveillance of Congenital Anomalies. Drug use rates were from European Monitoring Centre for Drugs and Drug Dependency. Median household income was from the World Bank. E-values provide a quantitative measure of robustness of results to confounding by extraneous covariates. Inverse probability weighting is an important technique for equalizing exposures across countries and removing sources of bias. Rates of CLA, hip dysplasia and the whole group of limb anomalies were higher in countries with increasing daily cannabis use (P = 1.81 × 10^-16, 0.0005 and 2.53 × 10^-6, respectively). In additive inverse-probability-weighted panel models, the limb reduction-resin Δ9-tetrahydrocannabinol (THC) concentration E-value estimate was 519.93 [95% lower bound (mEV) 49.56], order Resin > Herb ≫ Tobacco > Alcohol. Elevations were noted in 86% E-value estimates and 70.2% of mEVs from 57 E-value pairs from inverse-probability-weighted panel models and from spatial models. As judged by the mEV the degree of association with metrics of cannabis exposure was hip dysplasia > polydactyly > syndactyly > limb anomalies > limb reductions with median E-value estimates from 3.40 × 10⁶⁵ to 7.06 and median mEVs from 6.14 × 10³³ to 3.41. Daily cannabis use interpolated was a more powerful metric of cannabis exposure than herb or resin THC exposure. Data indicate that metrics of cannabis exposure are closely linked with CLAR and satisfy epidemiological criteria for causality. Along with Hawaii and the USA, Europe now forms the third international population in which this causal link has been demonstrated. Cannabis as a predictor of limb anomalies was more potent than tobacco or alcohol. Cannabinoid access should be restricted to protect public health and the community genome/epigenome transgenerationally.

Cannabinoid and substance relationships of European congenital anomaly patterns: a space-time panel regression and causal inferential study

With reports from Australia, Canada, USA, Hawaii and Colorado documenting a link between cannabis and congenital anomalies (CAs), this relationship was investigated in Europe. Data on 90 CAs were accessed from Eurocat. Tobacco and alcohol consumption and median household income data were from the World Bank. Amphetamine, cocaine and last month and daily use of cannabis from the European Monitoring Centre for Drugs and Drug Addiction. Cannabis herb and resin Δ9-tetrahydrocannabinol concentrations were from published reports. Data were processed in R. Twelve thousand three hundred sixty CA rates were sourced across 16 nations of Europe. Nations with a higher or increasing rate of daily cannabis use had a 71.77% higher median CA rates than others [median ± interquartile range 2.13 (0.59, 6.30) v. 1.24 (0.15, 5.14)/10 000 live births (P = 4.74 × 10^-17; minimum E-value (mEV) = 1.52]. Eighty-nine out of 90 CAs in bivariate association and 74/90 CAs in additive panel inverse probability weighted space-time regression were cannabis related. In inverse probability weighted interactive panel models lagged to zero, two, four and six years, 76, 31, 50 and 29 CAs had elevated mEVs (< 2.46 × 10³⁹) for cannabis metrics. Cardiovascular, central nervous, gastrointestinal, genital, uronephrology, limb, face and chromosomalgenetic systems along with the multisystem VACTERL syndrome were particularly vulnerable targets. Data reveal that cannabis is related to many CAs and fulfil epidemiological criteria of causality. The triple convergence of rising cannabis use prevalence, intensity of daily use and Δ9-tetrahydrocannabinol concentration in herb and resin is powerfully implicated as a primary driver of European teratogenicity, confirming results from elsewhere.

Endogenous Opiates and Behavior: 2018

This paper is the forty-first consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2018 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (2), the roles of these opioid peptides and receptors in pain and analgesia in animals (3) and humans (4), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (5), opioid peptide and receptor involvement in tolerance and dependence (6), stress and social status (7), learning and memory (8), eating and drinking (9), drug abuse and alcohol (10), sexual activity and hormones, pregnancy, development and endocrinology (11), mental illness and mood (12), seizures and neurologic disorders (13), electrical-related activity and neurophysiology (14), general activity and locomotion (15), gastrointestinal, renal and hepatic functions (16), cardiovascular responses (17), respiration and thermoregulation (18), and immunological responses (19).

Alternative splicing of the Wnt trafficking protein, Wntless and its effects on protein-protein interactions

Background

Wntless (Wls) is a protein that regulates secretion of Wnt signaling molecules from Wnt-producing cells. Wnt signaling is known to be critical for several developmental and homeostatic processes. However, Wnt-independent functions of Wls are now being elucidated. Primates express an alternative splice variant of Wls (here termed WlsX). WlsX contains an alternatively spliced COOH-terminus, and does not appear to be able to sustain significant levels of WNT secretion because of its inability to undergo retrograde trafficking to the endoplasmic reticulum. The functional significance for this alternatively spliced form of Wls has not yet been elucidated. We previously identified a cohort of Wls interacting proteins using a combination of yeast 2-hybrid and candidate gene approaches.

Results

In the present study, we analyzed the interaction of WlsX with previously identified Wls interactors, and additionally screened for novel protein interactors of WlsX utilizing a membrane yeast two hybrid screen. Three novel Wls interactors, Glycoprotein M6A (GPM6A), Alkylglycerol Monooxygenase (AGMO), and ORAI1 were identified. Each of these novel WlsX interactors, as well as all other Wls interacting proteins identified previously, with the exception of the mu-opioid receptor, were found to interact with both Wls and WlsX splice forms. We show that WlsX can form homodimers, but that WlsX may not interact with Wls.

Conclusions

WlsX has the ability to form homodimers and to interact with most known Wls interacting proteins. Taken together, our results suggest that Wls and WlsX may have overlapping, but distinct functions, including sensitivity to opioid drugs. While studies have focused on the ability of Wls interacting proteins to affect Wnt secretion, future efforts will explore the reciprocal regulation of these proteins by Wls, possibly via Wnt-independent mechanisms.

Direct visualization of the Wntless-induced redistribution of WNT1 in developing chick embryos

Paracrine Wnt signals are critical regulators of cell proliferation, specification, and differentiation during embryogenesis. Consistent with the discovery that Wnt ligands are post-translationally modified with palmitoleate (a 16 carbon mono-unsaturated fatty acid), our studies show that the vast majority of bioavailable chick WNT1 (cWNT1) produced in stably transfected L cells is cell-associated. Thus, it seems unlikely that the WNT1 signal is propagated by diffusion alone. Unfortunately, the production and transport of vertebrate Wnt proteins has been exceedingly difficult to study as few antibodies are able to detect endogenous Wnt proteins and fixation is known to disrupt the architecture of cells and tissues. Furthermore, vertebrate Wnts have been extraordinarily refractory to tagging. To help overcome these obstacles, we have generated a number of tools that permit the detection of WNT1 in palmitoylation assays and the visualization of chick and zebrafish WNT1 in live cells and tissues. Consistent with previous studies in fixed cells, live imaging of cells and tissues with overexpressed cWNT1-moxGFP shows predominant localization of the protein to a reticulated network that is likely to be the endoplasmic reticulum. As PORCN and WLS are important upstream regulators of Wnt gradient formation, we also undertook the generation of mCherry-tagged variants of both proteins. While co-expression of PORCN-mCherry had no discernible effect on the localization of WNT1-moxGFP, co-expression of WLS-mCherry caused a marked redistribution of WNT1-moxGFP to the cell surface and cellular projections in cultured cells as well as in neural crest and surface ectoderm cells in developing chick embryos. Our studies further establish that the levels of WLS, and not PORCN, are rate limiting with respect to WNT1 trafficking.