bluuebunny/crossref_metadata_2025_split huggingface dataset:
ATP‐BINDING CASSETTE TRANSPORTER ABCA1 IS DECREASED IN SKELETAL MUSCLE FROM INSULIN RESISTANT MICE
Authors: Llanos Paola , Sanchéz Pablo , Cerda‐Kohler Hugo , Arias‐Calderón Manuel , Diaz‐Vegas Alexis , Campos Cristián , Contreras‐Ferrat Ariel , Hidalgo Cecilia , Jaimovich Enrique 
Published: November 2023

INTRODUCTIONInsulin resistance (IR) is associated with obesity, metabolic syndrome and type 2 diabetes. Skeletal muscle is the main source of GLUT4‐mediated glucose transport in animals. Most GLUT4‐mediated glucose transport occurs in the transverse tubules (TT), a specialized cholesterol‐enriched plasma membrane system of skeletal muscle. In IR, GLUT4 translocation to the TT membrane is defective. Interestingly, we found that cholesterol levels in TT from skeletal muscle are higher in IR mice. We have centered our efforts in understanding the role of cholesterol accumulation in TT in muscle and its relation to IR. We have shown that the cholesterol‐lowering agent methyl‐β‐cyclodextrin promotes glucose uptake in adult muscle fibers and reduces insulin resistance in obese mice. Recent reports indicate that ATP‐binding cassette transporter ABCA1 (ABCA1), a transporter that mediates cellular cholesterol efflux, has a role in regulating lipid content, glucose tolerance and insulin sensitivity in adipose tissue. In skeletal muscle, however, a direct demonstration of the expression for ABCA1 during IR is lacking.MATERIAL AND METHODSMale C57BL/6J mice were fed with normal (NCD) or high fat diet (HFD) for 8‐weeks. qPCR, immunohistochemistry and immunocitochemistry were performed.RESULTSBoth, relative mRNA level and protein content of ABCA1 were decreased in muscle homogenates and isolated triads from HFD‐fed mice compared to NCD‐fed mice. In addition, ABCA1 decreased in transversal cross section of whole muscle and isolated fibers from HFD‐fed mice.DISCUSSIONThe results obtained will help us to define if changes in ABCA1 expression/function contribute to the anomalous cholesterol accumulation displayed by skeletal muscle TT membranes in IR condition. (pllanos@odontologia.uchile.cl)Support or Funding InformationFIOUCH‐ENLACE 001/2015 and FONDECYT 1151293 & 11150243
ACTIVITY OF SPHINGOMYELINASE IN PLASMA, URINE, AND TISSUES OF DIABETIC RATS
Authors: Bautista‐Pérez Rocio , Pérez‐Villavicencio Roxana , del Valle‐Mondragón Leonardo , Pérez‐Méndez Oscar , Franco Martha 
Published: November 2023

BackgroundSphingomyelinase (SMase) hydrolyse sphingomielin, releasing ceramide, and a cascade of bioactive lipids (sphingosine, and sphingosine‐1‐phosphate). SMase activation occurs in different cardiovascular system cell types. In the present study we investigated the changes in activity of SMase in kidney, aorta, heart, plasma and urine from diabetic rats.MethodsExperiments were performed in male Wistar rats weighing 300–350 g. The rats were divided into two groups: control (C) and streptozotocin‐induced diabetic (D)(n=10 each). The activity of SMase was determined using a method described by Bautista et al, 2015.ResultsAt day 30, diabetic animals exhibited hyperglycemia, lower body weight, glycosuria, diuresis. SMase activity decreased in the medulla and cortex renal as well as in plasma, but no changes were observed in aorta, heart and urine from rats diabetic.ConclusionsSMase activity may contribute to the accumulation of ceramide/sphingosine in the kidney and plasma from rats diabetic.
Delta‐9‐Tetrahydrocannabinol (THC) Self‐Administration in Male and Female Long Evans Rats
Authors: Wakeford Alison GP , Wetzell Bradley B , Pomfrey Rebecca L , Clasen Matthew , Taylor William , Riley Anthony L 
Published: November 2023

RationaleRodent preclinical assessments of THC self‐administration have failed to provide a robust and reliable animal model for the widespread use of marijuana in humans. Possibilities for this failure may be related to a) the lack of combining non‐psychoactive cannabinoids when examining THC self‐administration (given that marijuana derivatives abused by clinical populations contain cannabinoids other than THC) and b) the absence of assessments of sex differences in the acquisition of THC self‐administration (given that both clinical and preclinical data suggest that women may be more susceptible to drug use and abuse).MethodsTHC self administration was examined in male and female Long‐Evans rats under an FR1 schedule and across three doses (0.003, 0.01, 0.03 mg/kg/infusion). After each animal received five 2‐hour sessions with each dose (for a maximum of 15 days of intravenous self‐administration), they were then assessed for cocaine self‐administration (0.25 mg/kg/infusion; positive control) for 5 days or for THC self‐administration following pretreatment with cannabidiol at either a 1:1 or 1:10 CBD:THC ratio (all animals received both treatments, but were counterbalanced as to which treatment was received first).ResultsDiscrimination between the active and inactive lever was found for almost all animals at the 0.03 mg/kg/infusion dose, but no sex differences appeared between active lever presses or number of infusions. All animals acquired cocaine self‐administration and received more infusions of cocaine than any THC dose examined with females self‐administering more cocaine than males. Overall, cannabidiol failed to impact THC self‐administration, although there were instances in which individual subjects were affected.DiscussionThe failure to find robust THC self‐administration under optimized conditions suggests THC acts as a weak reinforcer in rodent models of self‐administration. These results will be discussed in the context of previous self‐administration research in rodents and primates, along with future research projects that may elucidate mechanisms or other conditions under which rodents might robustly self‐administer THC in an effort to better understand and possibly treat marijuana abuse and dependence.Support or Funding InformationFunding for this project was provided by American University's Office of Graduate Studies.
Physiological and Pharmacokinetic Effects of E‐cigarette Type Exposure to Δ9‐Tetrahydrocannabinol (THC)
Authors: Nguyen Jacques D. , Aarde Shawn M. , Vandewater Sophia A. , Grant Yanabel , Stouffer David G. , Parsons Loren H. , Cole Maury , Taffe Michael A. 
Published: November 2023

The increase in availability of electronic cigarettes (e‐cigarettes) for delivery of nicotine has led to the adaptation of these devices for the delivery of marijuana. Although there have been studies investigating the effects of intrapulmonary delivery of Δ9‐tetrahydrocannabinol (THC), no studies have investigated the effects of e‐cigarette type exposure in rodents. The goal of this study was to determine if vapor delivery of THC using e‐cigarette technology would produce cannabinoid‐typical effects observed in rodents using other routes of administration. Male Wistar rats received an injection of THC (0.3–10 mg/kg,i.p.) or were exposed to vaporized THC or crude marijuana extract in propylene glycol (PG) vehicle (200 mg/mL and 400 mg/mL respectively; 4 puffs per 5 min for 10–40 min). Rats were tested for changes in body temperature and nociception, and plasma THC content was analyzed using fast liquid chromatography/mass spectrometry (LC/MS). Vapor exposure to THC or crude extract significantly reduced body temperature up to 165 min following vape initiation. Tail flick latency was assessed using a hot water bath (52°C), and results showed increased latency up to 60 min post‐vape initiation. Plasma THC levels following a 10 mg/kg intraperitoneal injection were similar to levels produced by 30 min of inhalation exposure to THC in PG. Our results demonstrate that intrapulmonary delivery of THC using‐e‐cigarette type devices produces physiological effects, and this study validates this novel method of intrapulmonary THC delivery in rats.Support or Funding InformationDA024105 and DA035482
The Effects of Δ9‐Tetrahydrocannabinol (THC) Drug History on THC Taste and Place Conditioning
Authors: Hempel Briana , Wakeford Alison , Clasen Matthew , Friar Mary , Riley Anthony 
Published: November 2023

RationaleΔ9‐Tetrahydrocannabinol (THC) produces both aversive and rewarding effects in animal models. Given that the balance between a drug's affective properties is thought to underlie its abuse potential, it is important to consider these properties of THC and how they (and their balance) are impacted by various factors. In this context, previous studies have examined the effect of THC history on the aversive and rewarding effects of THC. However, such assessments have been made in different animals under different experimental procedures, making it difficult to assess the relative contribution of either affective property to abuse vulnerability.MethodsIn the present experiment, male Sprague‐Dawley rats were administered six pre‐exposure injections (3.2 mg/kg THC) over 12 days. This was followed by a combined taste avoidance/place preference procedure in which a novel saccharin solution and environment were paired with THC (0, 1 or 3.2 mg/kg). Changes in preferences and aversions for the drug‐paired stimuli were evaluated in final place and taste conditioning tests.ResultsRelative to control subjects, THC produced robust taste avoidance, but did not induce place conditioning. Pre‐exposure to THC attenuated THC‐induced taste avoidance and had no effect on place conditioning with THC.ConclusionsSimilar to prior work, THC induced robust and dose‐dependent taste avoidance. The failure to see THC‐induced place preferences is likely due to the aversive effects of THC masking its rewarding properties. Although THC pre‐exposure weakened the aversive effects of THC (as evidenced in the attenuated taste avoidance), some avoidance was still evident (THC‐injected animals drank less than controls). This suggests that the failure to see a change in THC‐induced place preferences following THC pre‐exposure was a function of its residual aversive effects limiting its relatively weak rewarding properties. These findings support the view that the interaction of reward and aversion is important in behavioral displays of the affective properties of abused drugs.Support or Funding InformationThis research was supported by a grant from the Mellon Foundation to Anthony Riley
Characterization of the Behavioral Phenotypes Underlying the Reinforcing Effects of Cannabinoid Receptor Agonists in Rhesus Monkeys
Authors: John William , Nader Michael 
Published: November 2023

The lack of a widespread, suitable method to establish robust levels of Δ9‐tetrahydrocannabinol (THC) self‐administration (SA) remains an impediment for developing treatments for human marijuana abuse. Therefore, the major objective of this study was to establish the experimental conditions necessary for demonstrating intravenous SA of THC as well as the cannabinoid receptor (CBR) agonist CP 55,940 in rhesus monkeys. In addition, behavioral phenotypes underlying the individual differences in CBR agonist SA were characterized in order to determine critical variables that could be modified to optimize the procedure. Rhesus monkeys (n=8), implanted with indwelling intravenous catheters, served as subjects and were trained to respond under a fixed‐ratio 10 schedule of food presentation, with a 60‐second timeout after each reinforcer. Once responding was stable, saline was substituted for food pellets for at least 5 consecutive sessions and until responding was extinguished (>80% reduction in responding for 3 consecutive sessions). After re‐establishing food‐maintained responding, CP 55,940 (0.005–1.0 μg/kg) and THC (0.03–10 μg/kg) were substituted for food pellets, with each dose available for at least 5 sessions and until responding was deemed stable. There was a return to food‐maintained responding, for at least 3 sessions, between different CBR agonist doses. CP 55,940 functioned as a reinforcer in three of eight rhesus monkeys at doses lower than previously tested in monkeys. Interestingly, in those three monkeys, non‐contingent administration of CP 55,940 was least potent in decreasing food‐maintained responding indicating an inverse relationship between the rate‐decreasing effects and reinforcing effects (r=0.81, p<0.05). No relationship was found between the reinforcing effects and CP 55,940‐induced hypothermia nor the unconditioned behavioral effects of the dopamine D2/D3 receptor agonist quinpirole. In those monkeys for which CP 55,940 functioned as a reinforcer, THC (0.03–3.0 μg/kg per injection) did not maintain responding higher than vehicle. Therefore, future experiments will determine if tolerance to the rate‐decreasing effects of THC will enhance the reinforcing effects of THC. Such an outcome would suggest that preclinical models require a period of repeated drug treatment before assessing THC SA.Support or Funding InformationSupported by DA06634 and T32AA007565.
Sex differences in alcohol‐induced HPA activation following systemic vs icv administration in rats: Gene expression studies
Authors: Wakley Alexa , Davis Seth , Yap Parry , Pham Charleen , Selvage Dan John 
Published: November 2023

Understanding how alcohol differentially affects the hypothalamic‐pituitary‐adrenal (HPA) axis in males vs. females is important for the development of sex‐specific pharmacological treatments for alcohol abuse. Our lab previously reported that centrally delivered alcohol activated hypothalamic‐pituitary‐adrenal (HPA) axis of rats in a sex‐ and estrous cycle‐dependent manner. This effect was greatest in females in stages of the estrous cycle when the effects of estradiol (E2) are high (proestrus and estrus), as these animals showed greater levels of HPA‐linked hormonal and neuronal activation by alcohol compared to males and to females in stages of the cycle when E2 levels are low (diestrus I and II). In the current study, we used male and normally cycling female rats receiving either intracerebroventricular (icv) or intraperitoneal (i.p.) alcohol injection to determine if there are differences between the ability of central versus systemic alcohol to cause sexually dimorphic changes in the expression of genes coding for neurotransmitters and enzymes implicated in HPA regulation. We also measured levels of the pituitary stress hormone adrenocorticotropin hormone (ACTH) at the time of sampling. Brain areas assessed for changes in gene expression included the paraventricular nucleus of the hypothalamus (PVN), which regulates hormonal and neuronal HPA function, and the locus coeuruleus (LC), which sends noradrenergic (NE) projections to the PVN and has been implicated in sexually dimorphic HPA responses to homeostatic challenges. Both icv and i.p. alcohol injection significantly stimulated ACTH secretion compared to vehicle controls, with this effect being greatest in proestrous rats for both treatment groups. However, neither alcohol administration route significantly altered the expression of corticotropin releasing hormone (CRF), which drives ACTH release, in the PVN or the LC. Icv alcohol stimulated a significant increase in expression of arginine vasopressin (AVP), which is known to contribute to ACTH secretion, in the PVN of proestrous females, but not in other groups. However, i.p alcohol did not alter the expression of this gene. Icv alcohol also significantly stimulated the expression of tyrosine hydroxylase (TH), the rate limiting enzyme for NE synthesis, in the PVN of all female groups and the LC of proestrous females, but not in males. Conversely, i.p. alcohol administration did not significantly alter TH expression in any groups. These results indicate that non‐CNS specific effects of alcohol in the periphery may alter gene responsiveness in areas of the brain that regulate HPA function.Support or Funding InformationR01 AA016947‐01A1
The Neurotoxic Effects of Manganese on Dopamine Post‐Synaptic Receptors Are Reversed by p‐Aminosalicylic Acid (PAS)
Authors: Dubose Loren , Loney‐Walsh Kurt , Carroll Margaret A , Catapane Edward J 
Published: November 2023

Manganese is a neurotoxin that causes the human disease Manganism. It disrupts dopamine neurotransmission in the brain, however the neurotoxic mechanism of action is not fully resolved and there is no effective clinical treatment for it. Reports in the literature postulate that manganese toxicity is more related to dysfunction of the post‐synaptic dopamine D2 receptors (D2DR) rather than degeneration of dopamine neurons. Our previous work showed that gill lateral ciliated cells of Crassostrea virginica have post‐synaptic dopamine receptors that are D2 type and are innervated by cilio‐inhibitory dopamine fibers via the branchial nerve. We also found that manganese treatments block the cilio‐inhibitory effects of dopamine on gill lateral cells and that treatments with manganese in the presence of the drug p‐aminosalicylic acid (PAS) prevented this toxic effect. Our previous immunofluorescence work with 1° antibodies against D2DR and FITC‐linked 2° antibodies showed that treatments with manganese caused reduced fluorescent intensity in the gill lateral cells, suggesting that manganese caused a loss of D2DR number or disruption of their structural integrity. In this study we hypothesized that PAS would reverse the neurotoxic effects of manganese on D2DR when applied after manganese exposure. To test this C. virginia were treated for up to 3 days with manganese (500 μM) followed by 5 more days with PAS (500 μM). Gills were excised, fixed, exposed to 1° antibodies against D2DR and FITC‐linked 2° antibodies, paraffin embedded, sectioned at 10 μm and then visualized on a fluorescence microscope. Fluorescence intensity was quantified using ImageJ software from NSF. The results showed that the fluorescence intensity in animals treated with manganese had a statistically significant progressive decrease in fluorescence of up to 40% less than non‐manganese treated controls. Animals treated with PAS after manganese and animals treated only with PAS did not show reduced fluorescence, indicating PAS reversed the manganese induced loss of post‐synaptic D2DR fluorescence. This immunohistological study shows a positive correlation between the losses of D2DR fluorescence in manganese treated animals vs controls. It also shows PAS effectively reversed the toxic effects of manganese on D2DR after 3 days of manganese treatments. The actions of PAS are likely due to its ability to chelate manganese. The results suggest that manganese chelating agents like PAS that can penetrate the human blood‐brain barrier might be effective therapeutic agents for Manganism.Support or Funding InformationThis work was supported in part by 2R25GM06003 of the Bridge Program of NIGMS and 0516041071 of NYSDOE.
Deorphanizing Renal Olfactory Receptor 1393
Authors: Shepard Blythe D , Peterlin Zita , Firestein Stuart , Pluznick Jennifer L 
Published: November 2023

Olfactory receptors (ORs) are G protein‐coupled receptors which serve to detect odorants in the nose. Recently, ORs have been shown to play novel roles beyond odorant detection in a number of tissues, and we previously determined that a subset of ORs are expressed in the kidney. One of these receptors is Olfr1393, an orphan receptor with no known ligand. In order to determine the physiological role of Olfr1393 within the kidney, it is important to understand its ligand profile. Unfortunately, most ORs are orphan receptors, due in large part to the inability to functionally express ORs in heterologous cell systems; ORs are retained in the ER and degraded when heterologously expressed. Luckily, with the assistance of chaperone proteins and a novel cleavable tag that we developed (Shepard, et al PLoS One 2013), we were able to express Olfr1393 on the cell surface of HEK293T cells. Thus, we undertook a large scale ligand screen using a cAMP‐dependent luciferase reporter assay. We began our unbiased screen using different odorant mixtures, each containing a variety of chemicals clustered by functional group such that the mixes, in sum, cover a wide “odorant space”. However, we did not observe any Olfr1393 activation using these libraries. The murine OR gene family (consisting of ~1000 ORs) is subdivided into subfamilies, grouped based on phylogenetic clustering and protein sequence identity, and ORs within a subfamily often share similar ligands. Olfr1393 belongs to the MOR256 subfamily, and several other MOR256 family members have been previously deorphanized. Thus, we screened Olfr1393 against known MOR256 odorants and found that Olfr1393 does respond to one of these chemicals – cyclohexanone. Using cyclohexanone as a guide, we broadened our search by using a multidimensional physiochemical metric for odorant prediction and identified a total of 8 different ligands. All 8 of these ligands are structurally similar, and can be broadly described as pre‐constrained rings containing either ketone or alcohol functional groups. Notably, if the ligand is modified even slightly (with the addition or removal of a functional group) it will no longer activate the receptor. Further unbiased screens ‐including the use of a 1280 compound chemical library ‐ did not reveal any additional ligands for Olfr1393 indicating the narrow range of its ligand profile. Efforts are currently underway to determine the physiological relevance of these 8 ligands using targeted metabolomics of murine urine and plasma; discovering the source of these ligands will contribute to the understanding that Olfr1393 plays in the kidney.Support or Funding InformationNIDDK
Studies of Ectopically Expressed Olfactory Receptor Olfr558/PSGR2: Gene Expression, Function And Novel Molecular Probes
Authors: Pronin Alexey , Volmar Claude‐Henry , Giulianotti Marc , Brothers Shaun , Slepak Vladlen Z 
Published: November 2023

An orphan G protein‐coupled receptor (GPCR), Olfr558 belongs to the class of olfactory receptors. However, in addition to the nasal cavity, it is also expressed in some blood vessels and in the prostate, including prostate cancer cell lines. The human ortholog of Olfr558 (OR51E1 or PSGR2) is dramatically up‐regulated in prostate cancer and is an established biomarker of malignancy. The human and mouse genes encoding this receptor are nearly identical (95%), which is unique for GPCRs in general, and particularly for sensory chemoreceptors. This unusual evolutionary conservation points to indispensability of its physiological function. While the function of this receptor or its native ligand is unknown, in vitro it responds to butyric acid by activating adenylate cyclase with ~25 micromolar EC50. We also found that growth of human prostate cancer cells that express PSGR2 is inhibited by butyric acid. Cells not expressing this gene were unaffected by butyrate. While butyric acid can be used in such experiments, its very low affinity and selectivity complicates interpretation of the data. Thus there is clear need for novel probes that can be used to dissect Olfr558/PSGR2 function. To address this need, we first established an expression system for Olfr558 in HEK293 cells that required addition of three specific tags its cDNA and co‐transfection with three chaperone proteins. We then used this cell system for a high throughput screening of a combinatorial chemical library, which identified chemical scaffolds that have agonist, antagonist and positive allosteric modulator activities. We performed structure‐activity relationship analysis and have begun optimization and subsequent functional analysis of these compounds. Since Olfr558/PSGR2 represents a large class of previously unexplored yet druggable targets, this project facilitates investigation of the entire family of ectopic olfactory receptors.Support or Funding InformationThis work is supported by NIH Grants R01DK105427 (VZS)