bluuebunny/crossref_metadata_2025 huggingface dataset:
Paraquat exposure induces dorsiflexor muscle dysfunction and dopaminergic modification resembling Parkinson's disease
Authors: Fahim Mohamed A , Nemmar Abderrahim , SHEHAB SAFA , ADEM ABDU , HASAN MOHAMED YOUSIF
Published: June 2021

Studies have shown that environmental factors such as exposure to pesticides and industrial toxins are implicated in the development of Parkinson's disease. Currently we have studied behavioral manifestations and motor function following exposure to the herbicide paraquat. Male rats were daily injected with paraquat (10 mg/kg i.p.) for 3 consecutive weeks. Activity boxes and rotarod systems were used for measuring locomotor activity and motor coordination. Moreover, the effects of paraquat on muscle contraction were also studied. Paraquat induced significant reduction in motor activity and difficulty in movement. These features appear to be similar to Parkinson's disease signs. Paraquat treatment also significantly reduced muscle twitch tension at the dorsiflexor skeletal muscle. Paraquat treatment also significantly reduced dopamine levels in the brain as measured by high performance liquid chromatography. Our histochemical studies indicated that chronic paraquat exposure significantly reduced the number of tyrosine hydroxylase positive neurons in the substantia nigra relative to vehicle‐treated rats. The present results further support the notion that toxins may predispose to Parkinson's disease or may contribute to the precipitation of the condition. Common toxic materials such as paraquat seems to have a role in the development of Parkinson's disease and paraquat can serve as a viable model for studying Parkinson's disease.
Differential ROS production in non‐neuronal brain cell subsets in response to Methamphetamine
Authors: Ali Sameh S. , Fox Howard , Conti Bruno , Marcondes Maria Cecilia Garibaldi
Published: June 2021

The production of Reactive Oxygen Species (ROS) leads to neurodegeneration in Meth abusers. We examined the contribution of ROS from non‐neuronal cells that affect local immunity and neuron survival in the brain. Using astrocyte (C8S), microglia (BV2) and macrophage (THP1) cell lines we show direct and differential effects of Meth on ROS pathways. Basal levels of H2O2 from macrophages and microglia (MM) were higher than those released by astrocytes. Meth reduced H2O2 in MM, but increased it in astrocytes, in a dose‐dependent manner. Rotenone, Superoxide Dysmutase and Antimycin A further reduced ROS in MM but increased it in astrocytes. This indicates that 1) mitochondria are important sources of H2O2 in MM, 2) superoxide is released to the extracellular space by astrocytes and 3) astrocytes have more tightly coupled mitochondria. In the presence of PMA, Meth highly exacerbated H2O2 production in astrocytes (> 400%) in a dose‐dependent manner, but MM cells produced less H2O2 at higher Meth dose. This indicates 4) a role of Meth downstream of the PKC feedback‐activation of NADPH oxidase (NOX) in astrocytes, and not in MM. Our data suggest that Meth directly enhances NOX‐generated ROS in astrocytes and reduces mitochondrial ROS in all cells, in an environment that excludes dopaminergic influence.
New Functional Measure of for Movement Disorder Detection, Progression and Efficacy of Intervention
Authors: Nelson Frank E , Ortega Justus D , Conley Kevin E
Published: June 2021

We know the daily functional tasks become harder to execute as we age. However, we do not know if the cause of this functional decline is the result of decreases in motor control in one area or a suite of areas. Recent work with the elderly and patients with movement disorders have developed several functional measures of overall decline. Each of these functional measures 1) initiation, 2) timing, 3) force steadiness, 4) error correction, and 5) neural integrity are linked to different regions of the brain. Here we use all five functional measures from different systems and adopt them to one simple biomechanical system. The system we chose is lateral movement of the index finger in holding and lifting a light load, timed tapping with and without external cues, and fast tapping. This movement is ideal for a sensitive measure since the biomechanical system only involves one joint, muscle and motor nerve. With these motor tasks and simple biomechanical system, we can explain 97% of the variance in motor control that naturally occurs with age. The outcome of our measurements is that on average there is not just one functional measure which declines with age, but a suite. This finding will be influential in the design of motor control rehabilitation program advising the targeting of suites of motor deficits instead of focusing on what seems like the primary motor deficit.
Calpain‐mediated dystrophin disruption may be a potential structural culprit behind chronic doxorubicin‐induced cardiomyopathy
Authors: Campos Erica C , Celes Mara R , Malvestio Lygia M , Prado Cibele M , Freitas Ana C S , Romano Minna M D , Rossi Marcos A
Published: June 2021

Studies from our laboratory demonstrated that alterations in the dystrophin‐glycoprotein complex (DGC), mainly dystrophin, and myofibrilar disruption are associated with increased sarcolemmal permeability in doxorubicin (DOX)‐induced cardiomyopathy. These alterations could be consequent to activation of calcium‐dependent proteases, mainly calpain, as cause of dystrophin and cellular constituents disruption.

This study tested the hypothesis that calpain is overexpressed in DOX‐treated rats and that dantrolene (DT), sarcoplasmic reticulum calcium inhibitor, could abrogate DGC alterations.

Rats received DOX only (cumulative dose 15 mg/kg); rats treated with DOX plus DT (5 mg/kg, i.p. immediately after each dose of DOX); control rats treated either with saline or saline plus DT. Fourteen days after the last injection, the hearts were collected for light microscopy, immunofluorescence and western blotting. Cardiac function was evaluated by echocardiography.

Increased expression of calpain, loss of dystrophin and cardiac dysfunction were observed in hearts treated with DOX only. In contrast, DT prevented increased calpain expression, dystrophin loss/reduction, and cardiac dysfunction, similarly to observed in controls. These findings support the opinion that calpain mediate dystrophin loss/reduction and it might be a structural culprit behind DOX‐induced heart failure. FAPESP.
Doxorubicin induces early left ventricular dysfunction and metalloproteinase activation in rats
Authors: Polegato Bertha Furlan , Azevedo Paula Schmidt , Minicucci Marcos Ferreira , Chiuso-Minicucci Fernanda , Castan Eduardo , Carvalho Robson Francisco , Matsubara Beatriz Bojikian , Matsubara Luiz Shiguero
Published: June 2021

Pathophysiological mechanism of the acute doxorubicin‐induced cardiotoxicity is not fully understood. The purpose of this study was to evaluate alterations in cardiac structure and function 48 hours after doxorubicin infusion in rats. Thus, male Wistar rats (n = 35) received an intraperitonealy single‐dose of doxorubicin (20 mg / kg) or saline (control group). Morphological, functional and biochemical analysis were performed. Echocardiographic analysis showed increased in isovolumetric relaxation time (20.3 ± 4.3 ms vs 24.7 ± 4.2 ms; p=0.007) and decreased left ventricular fractional shortening (0.59 ± 0.07 vs. 0.51± 0.05; p<0.001) in treated rats. This group also presented increased myocardial passive stiffness in isolated perfused heart study (14.7 ± 1.5 % vs 12 ± 2.2 %; p<0,05). There were no changes in TNF‐á, IFN‐ɤ, IL‐1 and ICAM‐1 or gene expression of ryanodine receptor, fosfolamban and Serca‐2a between groups. However, there were activation of MMP 2 (0.11 ± 0.01 vs 0.06 ± 0.02; p=0.002) and MMP 9 (0.07 ± 0.01 vs 0.05 ± 0.01; p=0.009) in the myocardium of the treated rats. In conclusion, doxorubicin caused early systolic and diastolic dysfunction, and this dysfunction is associated with increased MMP 2 and 9 activity.
Echocardiographic Apporach to Dissect the Effect of Dyssynchrony on Left Ventricular Function in Heart Failure.
Authors: Shizukuda Yukitaka , Ahmad Saad , Attari Mehran , Costea Alexandru , Muth James
Published: June 2021

Left ventricular (LV) dyssynchrony (DYS) is believed to affect LV function. Despite extensive research, no clinically feasible method to assess the negative effect specific to DYS on the LV function has been established. To clinically evaluate this effect, we used global strain (GS) derived from color‐coded tissue Doppler imaging (TDI), as a surrogate to predict LV systolic performance and E’4, the average of peak E velocity of septal, lateral, anterior, and inferior mitral annulus as to predict early diastolic relaxation with echocardiography. We analyzed 104 consecutive patients at our laboratory from 2007 to 2009 who presented with heart failure [ages; 57±14, LVEF; 29.8±11.9%, 43 (41%) females, mean±SD]. The GS was evaluable in 61 patients (59%) and E’4 was evaluable in 83 patients (80%). GS was significantly linearly correlated with LV ejection fraction in both patients with DYS and without DYS, but these linear relationships differed statistically in these two groups by ANCOVA indicating that GS may be used to detect the specific effect of DYS on LV systolic function. On the other hand, E’4 significantly correlated with GS, LV ejection fraction, and age, but not echocardiographic measures of DYS indicating that LV early diastolic relaxation may not be affected by DYS. In conclusion, echocarciographic approach is promising to clinically evaluate the specific effect of DYS on LV function in heart failure populations.
Phthalate exposure increases fatty acid oxidation in cardiac muscle cells
Authors: Posnack Nikki , Idrees Rabia , Swift Luther , Lee Norman , Sarvazyan Narine
Published: June 2021

Di(2‐ethylhexyl)phthalate (DEHP) is a widely used plasticizer found in a variety of medical products. Confluent layers of neonatal rat cardiomyocytes were exposed to clinically relevant concentrations of DEHP for 72 hours. Affymetrix 1.0 ST arrays were utilized to assess changes in gene expression following DEHP exposure, and mRNA expression was validated by qRT‐PCR. Gene ontology (GO) analysis revealed significant over‐representation of GO categories associated with metabolic processes in DEHP‐treated samples. Specifically, DEHP exposure resulted in a significant upregulation in genes associated with fatty acid oxidation. To confirm microarray data, cardiomyocytes were cultured in glucose‐free culture media containing physiological concentrations of fatty acids. DEHP‐treated cardiomyocytes utilized a significantly higher amount of fatty acids compared with control samples. Moreover, immunocytochemistry revealed enhanced staining for mitochondria and PPARα in DEHP‐treated samples compared with control. Studies conducted using a PPARα agonist (Wy‐14643) suggested that the observed changes in utilization of metabolic substrates can be explained, at least in part, by upregulation of the PPARα nuclear receptor. Supported by the NIH (F32ES019057 to NGP).
Mountain‐top mining particulate matter exposure increases markers of mitochondrially‐driven apoptosis in rat cardiac tissue
Authors: Nichols Cody Edward , Baseler Walter A. , Thapa Dharendra , LaFata Gabrielle , Croston Tara L. , Shepherd Danielle L. , Lewis Sara E. , Knuckles Travis L. , McCawley Michael , Hendryx Michael , Nurkiewicz Timothy R. , Hollander John M.
Published: June 2021

Particulate matter (PM) exposure has been associated with adverse health effects in many different regions throughout the US. In the Appalachian region, research has shown that there is a higher incidence of chronic cardiovascular disease in regions with local mountain‐top mining (MTM) operations. The goal of this study was to determine the effect of MTM PM exposure on cellular apoptotic pathways within the heart. Sprague Dawley rats were exposed to MTM PM, collected within one mile of an active MTM site, through intratracheal instillation and heart tissue examined. Bax/Bcl‐2 ratio was significantly increased in exposed rats relative to control (p<0.05) suggesting an increase in cellular apoptosis. Caspase‐3 and ‐9 activities were significantly increased in exposed rats relative to control (p<0.05) with no change in caspase‐8, suggesting an increase in mitochondrially‐driven apoptosis. Putative mitochondrial permeability transition pore constituent, cyclophillin D, was increased in exposed rats compared to control (p<0.05). These results indicate that mitochondrially‐driven apoptosis is upregulated in the heart following MTM PM exposure which may be associated with an increase in a key transition pore constituent. (Support: NIH DP2DK083095, NIH T32HL090610, AHA 10PRE3420006, NIH RO1ES015022, RC1 ES018274, NIH 5P20RR016477)
LBSO potentiate the effects of Hg in breast cancer cells
Authors: Sanchez Karla Rubi , Ishaque Ali , Egiebor Egbe
Published: June 2021

Breast cancer is the second major cause of death in women. Reports show that breast cancer cells have high level of glutathione. This research was done to characterize the kinetic signature and mechanism of cell death using the oxidative stress pathway when mercury (Hg) and L‐buthionine sulphoximine (LBSO, inhibits glutathione production) are presented to MCF‐7 cells. The hypothesis tested is that the potentiating effects of LBSO will be higher with Hg than with As. Production was inhibited by treating the MCF7 cell line with 2.5 mM (LBSO) and then exposed to mercury 5.4ppm Hg. The cytotoxic effect was studied in real time using Real Time Cell Electronic Sensing (RTCES). To determine the oxidative stress pathway used, mitochondrial transmembrane potential (∆øm), Reactive Oxygen Species (ROS), superoxide anion and Glutathione (GSH) levels were studied using Rhodamine123 fluorescent (Rho123), 2′,7′‐Dichlorodihydrofluorescein (H2DCFDA), Dihydroethidium (DHE), 5‐Chloromethylfluorescein diacetate (CMFDA) dyes respectively. Each sample, 10,000 events were collected using FACSCalibur flow cytometer. ROS and O2 • levels were expressed as mean fluorescence intensities (MFI), calculated with CellQuest. The results did not show a vast difference between Hg and LBSO and Hg alone. Results reveal that Hg might be a better candidate for cancer therapy compared to As due to As high toxicity.
CaMKK2 regulates cellular proliferation and androgen receptor activity during prostate cancer progression
Authors: Karacosta Loukia Georgiou , Foster Barbara A. , Azabdaftari Gissou , Feliciano David M. , Edelman Arthur M.
Published: June 2021

Mounting evidence suggests that the androgen receptor (AR) plays a critical role in prostate cancer (PCa) progression. However, the molecular mechanisms by which the AR regulates cell proliferation in androgen‐dependent and castration‐resistant PCa are incompletely understood. We report here that calcium/calmodulin‐dependent kinase kinase 2 (CaMKK2) expression increases during progression of human PCa and becomes nuclear or perinuclear in advanced disease. In a mouse model of PCa (Transgenic Adenocarcinoma of Mouse Prostate, TRAMP), CaMKK2 expression increases with progression and is predominantly nuclear. CaMKK2 expression is markedly higher in the AR‐expressing, tumorigenic cell line LNCaP compared to cell lines which are AR‐non‐expressing and/or non‐tumorigenic. Silencing of CaMKK2 expression by RNA interference (RNAi) reduces cell proliferation in LNCaP cells but not in AR‐non‐expressing PC3 cells. In LNCaP cells, dihydrotestosterone (DHT) induces CaMKK2 mRNA and protein expression while androgen withdrawal suppresses CaMKK2 expression. RNAi of CaMKK2 reduces expression of the AR target, prostate specific antigen (PSA) and the cell cycle regulators cyclin D1 and phospho‐pRB. Our results suggest that in PCa progression, CaMKK2 is transcriptionally induced by the AR to maintain AR activity, AR‐dependent cell cycle control and continued cell proliferation. Supported by UB Foundation.
Selective cytotoxicity and combinatorial effects of camptothecin or paclitaxel with sodium‐R‐alpha lipoic acid on A549 human non‐small cell lung cancer cells
Authors: Sinko Patrick J. , Ibrahim Sherif , Gao Dayuan
Published: June 2021

Non‐small cell lung cancer (NSCLC) is the most common type of lung cancer and remains the deadliest cancer in the United States and worldwide. New and innovative therapies are highly sought after to improve therapeutic outcome, one of which is combinatorial therapy. The effect of sodium‐R‐alpha lipoic acid (ALA) on camptothecin‐ and paclitaxel‐induced cytotoxicity was evaluated in A549 human NSCLC adenocarcinoma cells and BEAS‐2B ‘normal’ human lung epithelial cells. Combination and Dose Reduction indices (CI and DRI, respectively) were investigated by studying ALA (0–16 mM), camptothecin (0–25 nM) and paclitaxel (0–0.06 nM) alone and in various combinations. 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) was used to assess cytotoxicity. The interactive cytotoxic effects of ALA with camptothecin (CPT) or paclitaxel (PXL) were analyzed using an automated simulation of dose effects (CompuSyn®3.01 software). The effects of ALA on camptothecin‐and paclitaxel‐induced cytotoxicity varied based on concentrations and treatment times. CIs [Additive (CI=1); Synergistic (CI<1); Antagonistic (CI>1)] were lower for the CPT/ALA combination (~0.17–1.5) than the PXL/ALA combination (~0.8–9.9). DRIs were higher for the CPT/ALA combination (~2.2–22.6) than the PXL/ALA combination (~0.10–8.3). Interestingly, it was also found that ALA was not cytotoxic towards BEAS‐2B lung epithelial cells. Based on the current studies, CPT/ALA is a more favorable combination than PXL/ALA in terms of in vitro cytotoxic effects toward A549 human NSCLC adenocarcinoma cells. The selective nature of ALA implies that co‐administration of this agent with CPT may potentiate the effects and reduce the required dose of CPT. Support: NIH 1RO1CA155061.
Effects of selected adrenergic receptor agonists on human breast cancer progression, in vitro
Authors: Philipose Christina , Patel Kartik K. , Bavadekar Supriya A.
Published: June 2021

Recent reports have suggested an association between adrenergic receptor (AR) agonists and progression of cancer leading to increased cell proliferation, angiogenesis, and metastasis. Current evidence suggests that these effects may be mediated via the β2‐AR. In this study, human metastatic, hormone‐insensitive, breast cancer cells, MDA‐MB‐231, known to express β2‐AR, were treated with varying concentrations (ranging from 10−9M to 10−3M) of the AR agonists, norepinephrine (NE), epinephrine (E), and isoproterenol (ISO) for 24 hr. The agonists produced a concentration‐dependent increase in cell viability in the 10−5 to 10−3 M range, as assessed using the XTT cell proliferation assay. Increase in cell viability observed with 10−3 M of NE, E, and ISO was about 9–10 fold. There was no rank order of potency observed between the agonist ligands. Pretreatment with α‐ and β‐AR selective antagonists, phentolamine (10 μM), propranolol (10 μM), and ICI 118,551 (10 μM) did not inhibit the increase in cell viability. Further experiments are needed to explore the underlying mechanism of increased viability observed with these agonists, and also to assess their effects on angiogenesis and metastasis in these cells. This research work is supported by the Division of Pharmaceutical Sciences at Long Island University, Brooklyn, NY.
siRNA‐Mediated Down‐regulation of Vascular Endothelial Growth Factor in MCF‐7 cells
Authors: Patel Khyati Rohit , Bhatt Vrushank D , Boggeti Renuka , Ratna Warren N
Published: June 2021

Vascular endothelial growth factor (VEGF) promotes angiogenesis and vascularization. Inhibition of angiogenesis results in tumor regression. VEGF induces endothelial cell proliferation, promotes cell migration, and inhibits apoptosis. Deregulated VEGF expression contributes to angiogenesis and tumor growth and the etiology of several other diseases that are characterized by abnormal angiogenesis. VEGF family of genes include VEGF‐A, VEGF‐B, VEGF‐C and VEGF‐D. To investigate targeted degradation of VEGF mRNA using short interference RNA (siRNA) as a means to inhibit VEGF expression, MCF‐7 human breast cancer cells were transfected with phosphothioester siRNAs designed to degrade VEGF mRNAs. RNA was extracted by NP‐40 lysis method and analyzed by Reverse Transcription‐Polymerase Chain Reaction (RT‐PCR) and Northern blotting. Western blot analysis was performed on whole cell lysates. RT‐PCR and Northern blot analysis showed siRNA‐mediated degradation of VEGF mRNA. Western blot analysis showed a corresponding decrease in the expression of VEGF. The above results indicate the potential use of siRNA for the down regulation of VEGF expression and consequently cause tumor regression. This work was supported by science research funds from Arnold and Marie Schwartz College of Pharmacy, Long Island University, Brooklyn, NY.
A 3D co‐culture system for high‐throughput screening of anti‐angiogenic and anti‐tumorigenic combination therapies
Authors: Connor Yamicia D , Oh Michael S , Tekleab Sarah , Bharat Divya , Gill Navjot K , Sengupta Shiladitya
Published: June 2021

The future of cancer therapy relies on robust drug combinations. Traditional screening for drug discovery uses 2D monocultures. However, recent studies have shown that 3D cultures provide a more physiological platform to study cancer. Unfortunately, these systems do not capture interactions between tumor cells and the angiogenic component. The goal of this work is to establish a 3D in vitro co‐culture system combining these components to create a high‐throughput model to study cell interactions and screen anti‐angiogenic and anti‐tumorigenic therapies. Human endothelial cells were allowed to undergo tubulogenesis in a matrigel matrix to which metastatic breast cancer MDA‐MB‐231 cells were added. Interestingly, instead of forming embryoid bodies, the MDA cells align and incorporate into the endothelial vessels. Using this model system, we elucidate FAK and β1 integrin as mediators of the cell interactions. RNAi inhibition of FAK and β1 integrin resulted in the disruption of the architecture with 3.4 (p<0.001) and 8.6 (p<0.001) fold change in cell interactions, respectively. To probe downstream mediators of the FAK‐β1 signaling pathway, small molecule inhibitors were used to perturb this architecture, resulting in a 68% (p<0.05) decrease in invasive capacity. In conclusion, our studies show that a 3D co‐culture system provides a powerful platform for screening combination therapies.

Supported by DoD BCRP.
Dopamine and Isoproterenol Depolarize Corticotrophin Releasing Factor Neurons in the Bed Nucleus of the Stria Terminalis: A Potential Neurocircuit Involved in Relapse
Authors: Silberman Yuval , Matthews Robert T , Winder Danny G
Published: June 2021

Relapse is a significant challenge to successful treatment of addictions. Corticotrophin releasing factor (CRF) mediated activation of the bed nucleus of the stria terminalis (BNST) may play an important role in relapse behaviors. Previous reports suggest a serial circuitry in the BNST where drug‐associated cues, via increased dopamine levels, or exposure to stress, via increased norepinephrine levels, may increase CRF levels in the BNST thereby precipitating relapse. However, there is little evidence confirming this hypothetical neurocircuit. Thus, we sought to determine if dopamine or the β‐adrenergic receptor agonist, isoproterenol, can directly modify CRF neuron activity in the BNST. Mice expressing CRF fluorescent‐tagged neurons were used and CRF neuron activity was monitored using whole‐cell patch‐clamp electrophysiological methods. Acute application of dopamine and isoproterenol significantly depolarized BNST CRF neurons in persistent manner. Together with the finding that CRF enhances excitatory neurotransmission onto BNST projection neurons, these data suggest that both dopamine and isoproterenol may directly enhance CRF release from local BNST sources potentially precipitating relapse behaviors. Potential pharmacotherapies targeting this BNST circuit may be useful in the prevention of relapse to drug and alcohol addiction. Funding: NIH grants AA020140 and AA019455
Modulation of Central Fatigue‐Associated Neural Factors by Cancer Chemotherapy Agent 5‐Fluorouracil
Authors: Jung Seung Ho , Murphy E. Angela , Fayad Raja , Pena Maria , Gordon Benjamin , Carmichael Martin , Davis J. Mark
Published: June 2021

A dearth of studies has attempted to elucidate the etiology of cancer‐related fatigue (CRF). The purpose was to determine effects of chemotherapy agent 5‐fluorouracil (5FU), known to induce CRF, on cytokines and neurotransmitter systems in distinct regions of the brain that are implicated in the development of central fatigue.

Methods

Mice were intraperitoneally injected with 5FU or saline (placebo) for 5 days and sacrificed 12‐hrs (post‐1) or 9 days (post‐9) after the last injection.

Results

5FU induced a significant increase in mRNA expression of IL‐1β on post‐9 (p < 0.05) in the brainstem and cerebellum and 5‐HT2A receptor in the cerebellum on post‐1(39%, p < 0.05). There was a trend for elevated mRNA expression of dopamine D2 receptor on post‐1 (6% and 16%) and post‐9 (32% and 22%) in the brainstem and cerebellum respectively. The cerebellum showed a slight increase in mRNA expression of 5‐HT1A receptor on post‐1 (30%) and post‐9 (21%). Our data revealed positive correlations among 5‐HT1A/B, 5‐HT2A and D2 receptors. MCP‐1 mRNA expression was positively correlated with IL‐1β, 5‐HT1B and 5‐HT2A in the brainstem (p < 0.05).

Conclusion

Our results are the first to show that 5FU have an impact on IL‐1β and serotonin and dopamine receptors in the brainstem and/or cerebellum which provide strong evidence for current theories of the development of central fatigue and, therefore, for CRF induced by 5FU.
Investigation of the role of corticotropin‐releasing factor receptors within the central amygdala and basolateral amygdala during nicotine withdrawal in rats
Authors: Ji Yue , Alexander Jon C. , Bruijnzeel Adrie
Published: June 2021

Abrupt cessation of tobacco smoking in humans is associated with negative affective symptoms such as depressed mood and anxiety. Evidence indicates that this dysphoric state associated with nicotine withdrawal is one of the motivational factors for the continuation of tobacco smoking. Cessation of chronic nicotine administration in rodents induces affective withdrawal signs which can be investigated using the intracranial self‐stimulation (ICSS) procedure. The amygdala is hypothesized to play a key role in both the positive and negative reinforcing properties of drugs of abuse. Injections of the specific CRF1 antagonist R278995/CRA0450 into the central amygdala attenuated elevations in brain reward thresholds, whereas injections into the basolateral amygdala showed no effect. Funded by NIDA Grant # DA023575
Acute effects of d‐methamphetamine, 3,4‐methylenedioxypyrovalerone, 3,4‐methylenedioxymethamphetamine, and 4‐methylmethcathinone on wheel activity in rats
Authors: Huang Pai-Kai , Aarde Shawn M. , Dickerson Tobin J. , Taffe Michael A.
Published: June 2021

A recent DEA report and ongoing media accounts show increasing recreational use of 4‐methylmethcathinone (4‐MMC, mephedrone) and 3,4‐methylenedioxypyrovalerone (MDPV). Some severe sympathomimetic symptoms, hallucinations, psychoses, and even deaths have been reported. Recent studies showed that 4‐MMC and MDPV enhanced DA neurotransmission, while 4‐MMC also increased 5‐HT neurotransmission, much like 3,4‐methylenedioxymethamphetamine (MDMA). Therefore these novel cathinone recreational drugs may predict differential abuse potential and toxicities, as is the case for designer amphetamines. This study determined relative locomotor stimulant effects of 4‐MMC and MDPV, in comparison with d‐methamphetamine (METH) and MDMA, in male Wistar rats provided an activity wheel. Results showed a biphasic pattern for METH and MDPV, with increased wheel activity following lower doses and inhibition of activity at the highest dose. Monophasic, dose‐dependent reductions in activity were produced by MDMA and 4‐MMC. The data suggests MDPV produces typical locomotor stimulant effects whereas 4‐MMC is more similar to the entactogen MDMA. USPHS grants: DA024105 and DA024705.
Role of mu opioid receptor endocytosis in the beneficial and side‐effects of prolonged opioid use
Authors: Whistler Jennifer Lynne , Berger Amy Chang , Madhavan Anuradha , Enquist Johan , He Li , Ferwerda Madeline , Kim Joseph
Published: June 2021

The utility of morphine for chronic pain is hindered by the development of analgesic tolerance and dependence. For decades the field has hypothesized that tolerance is mediated by “desensitization” of opioid receptors. In fact, morphine and its derivatives are unique agonists because they do not promote endocytosis of their target receptor, the mu opioid receptor (MOR) while, paradoxically, the endogenous ligands do. In light of this, we propose that endocytosis and recycling serves a protective role in reducing opioid tolerance and dependence. To examine this hypothesis, we generated a knock‐in mouse that expresses a mutant form of the MOR, RMOR for recycling MOR, that endocytoses and recycles in response to morphine. Mice expressing RMOR show enhanced analgesia and reward to morphine compared to wild type (WT) mice and equivalent analgesia and reward to drugs that drive endocytosis in both genotypes. Importantly, mice expressing RMOR develop reduced tolerance and physical dependence to morphine, and do not transition to compulsive drug seeking even after weeks of voluntary morphine consumption, unlike WT mice. Together, these results suggest that drugs that drive endocytosis of the MOR would retain the beneficial effects of opiates including analgesia and reward, while reducing the liability for the side effects of tolerance, dependence and addiction. Supported by DA019958 and the State of California/UCSF.
Naloxone reverses thrombin‐induced increase in TxB2 in patients treated with subtherapeutic dose of ketamine during wisdom teeth extraction
Authors: Gujjar Meera S. , Gunturi Rahul , Grogan David M , Sharma Avadhesh C.
Published: June 2021

In a prospective clinical study, we hypothesized that administration of a sub‐therapeutic dose of Ketamine (0.2 mg/kg) intraoperative would reduce the activity of TXB2 at 0 and 72 hours post surgery. Blood samples were obtained from Ketamine‐treated and untreated patients at three designated time points: before surgery, immediately (0 h) and 72 h after surgery. Purified platelets were obtained from the samples to assess TXB2 activity. The suspension of purified platelets (1e6 cells/mL) was equally divided into four treatment groups (n=3): vehicle (100 μL saline), Thrombin (2 unit/mL), Naloxone (0.1 mM), and Naloxone + Thrombin groups. Immediately following surgery both Ketamine‐treated and ‐untreated patient samples exhibited a decrease in TXB2 levels; however the Ketamine‐treated group TXB2 levels were significantly higher than the untreated group. At 72 h post‐surgery, a significant increase in concentration of TXB2 was observed. Thrombin treatment of purified platelets showed a significant increase in TXB2 levels before surgery, an effect which persisted only in the Ketamine‐treated group after surgery. The Thrombin induced increase in TXB2 levels following sub‐therapeutic dose of Ketamine was reversed by Naloxone treatment immediately after surgery, but not 72 h after surgery. The data suggests that intraoperative use of sub‐therapeutic dose of Ketamine modulates TXB2 levels in a Naloxone‐sensitive manner. (Funded by Oral Maxillofacial Surgery Foundation)
Sensitization of morphine‐induced motor stimulation: age‐related differences in mice
Authors: Koek Wouter
Published: June 2021

Given evidence for age‐related differences in effects of drugs of abuse, surprisingly few studies have explored effects of opioids in adolescents (versus adults). This study compared sensitization of morphine‐induced locomotion in adolescent and adult mice.

Male C57BL/6J mice were treated with saline or morphine (10–100 mg/kg, i.p.) once per day for 4 days, and morphine (3.2–56 mg/kg)‐induced locomotion was assessed 3 days or 5 weeks later. Three days after repeated saline, morphine increased locomotion more in adolescents than in adults. Repeated morphine (minimum effective dose: 17.8 mg/kg) enhanced morphine‐induced locomotion to a similar extent in each age group (1.6 – 1.9 fold). This enhancement was still evident 5 weeks later, when the adolescents had become adult, but was smaller (1.4‐fold) and occurred at a higher dose (56 mg/kg). In animals treated repeatedly with morphine as adults, enhancing effects were no longer apparent 5 weeks later.

Repeated administration of morphine produced similar short‐term enhancement of its motor stimulating effects in all age groups, but evidence for long‐term enhancement was obtained only in adolescents. These findings suggest that compared with adults, adolescents are more sensitive not only to the acute locomotor stimulating effects of morphine, but also to its long‐lasting locomotor sensitizing effects.

Supported by DA23261
Effects of early neurotoxicity from chemotherapeutic agents on learning, novelty, and drug reward
Authors: Bisen-Hersh Emily B , Myers Alyssa M , Walker Ellen A
Published: June 2021

An increased survival rate among children diagnosed with acute lymphoblastic leukemia (ALL) has led to interest in late effects. Although intrathecal chemotherapy has possibly reduced the severity of cognitive impairments, the long‐term effects of specific chemotherapeutic agents are largely unknown. A preclinical mouse model of ALL treatment was used to investigate the developmental effects of neonatal exposure to methotrexate (MTX) and cytarabine (Ara‐C) on learning and novelty in adolescence. Pups were treated on PND 14, 15, and 16 with saline, MTX (1.0 or 2.0 mg/kg), Ara‐C (10 or 20 mg/kg), or a combination of MTX and Ara‐C (1.0 and 10 mg/kg or 2.0 and 20 mg/kg). Behavioral testing began at PND 35. Mice treated with MTX, presented alone or in combination with Ara‐C, displayed a significantly slower acquisition and impaired retention on the autoshaping task. On the novel object task, chemotherapy‐treated mice showed a significant decrease in latency to approach a novel object. During the recognition trial, chemotherapy‐treated mice spent equal time exploring both objects. The occurrence of only mild deficits on the conditional discrimination task support that extensive training may ameliorate learning impairments. The consequences of treating these deficits using psychostimulants will also be discussed. Findings highlight the usefulness of preclinical models to examine the developmental effects of early chemotherapeutic treatment on future learning, as well as to study potential means of cognitive remediation in this population. (Supported by RO1 CA129092 and T32 DA07237).
Development of a mouse autoshaping model to test for short‐term memory impairment
Authors: John Joel S , Walker Ellen A
Published: June 2021

Short term memory loss and memory disruption are prominent clinical symptoms in the Alzheimer's disease and other dementias. The purpose of the present study was to develop an objective mouse model of short term memory loss that can be pharmacologically manipulated to test novel compounds. To this end, we modified a rat autoshaping model (Menses et al., 2007) for mice. Male, Swiss‐Webster mice were placed within experimental chambers to measure the acquisition of nose‐poke responding in the presence of an audible tone presented on a variable‐interval schedule to earn 10 Ensure solution rewards. After the completion of the first session, mice are injected with saline or a dose of drug and returned to their home cages. One hour later, mice were returned to the chambers to measure retention of the autoshaped response. Mice injected with saline, responded faster and more accurately during the second session indicating retention of the learned response. Mice injected with NMDA noncompetitive antagonist ketamine (3.2–18 mg/kg) or scopolamine (1–10 mg/kg) failed to show a significant difference from the first and the second session without rate suppression indicating memory impairment. Future studies will examine standard and novel agents to reverse the effects of ketamine and scopolamine to further test the utility and validity of this short term memory mouse autoshaping model. (Supported by R01CA129092).
Repeated Forced Swim Stress Induces Learned Helplessness in Rats
Authors: Saha Kaustuv , Eikenburg Douglas , Taneja Manish , Salim Samina , Bicol Kayla
Published: June 2021

The goal of our study was to determine if another form of inescapable, uncontrollable stress, milder than repeated electric shock, could induce learned helpless (LH) behavior in rats and if antidepressant drugs can prevent this behavior. Rats were first exposed to repeated forced swim stress (RFS) and 24 hr after last swim, rats were tested for escape behavior [Escape Latency (EL) and % Escape Failure (EF)] in a shuttle‐box. RFS segregated the stressed rats into two clusters based on EL and EF. One cluster, LH, showed increased EL (27.1 ± 1.4 s) and EF (82.7 ± 8 %) compared to controls (11.1 ± 1.3 s; 11.7 ± 4.3%), showing stress susceptibility. The other cluster, non‐helpless (NH), showed EL (8.8 ± 2.4s) and EF (11.5 ± 5.3%) similar to the controls. All RFS rats performed similar to controls in the open field and elevated plus maze tests, suggesting the absence of locomotion deficits or increased anxiety. In rats pretreated for 10 days with desipramine (DMI), no increased EL or EF were observed in the shuttle‐box after RFS. DMI also prevented a reduction in GRK3 in the locus coeruleus observed after RFS in untreated LH rats. These data suggest that, like inescapable unpredictable shock, RFS can induce LH in rats, which is prevented by DMI pretreatment. Hence, RFS is another inescapable stress paradigm that can identify stress‐susceptible and stress‐resilient populations in rats. (Supported by NARSAD)
SERT and BDNF heterozygous knockout mice display alterations in grooming activity and syntax
Authors: Kyzar Evan , Gaikwad Siddharth , Green Jeremy , Roth Andrew , Pham Mimi , Stewart Adam , Kalueff Allan
Published: June 2021

Animal self‐grooming behavior is becoming increasingly important in neuroscience research. In the present study, we assessed grooming behavior in serotonin transporter SERT (+/+ and +/−) and brain‐derived neurotrophic factor BDNF (+/+ and +/−) adult male C57BL/6J mice. Custom‐upgraded HomeCageScan video‐tracking software (Clever Sys. Inc., Reston, VA) was used to record spontaneous novelty‐evoked mouse grooming behavior in transparent observation cylinders for 5 min. SERT +/− mice showed an overall increase in grooming behavior compared to +/+ mice, without altering locomotory responses. In contrast, BDNF +/− mice displayed a global decrease in both distance traveled and grooming behavior, indicating an overall reduction in activity. Both mutant strains also showed enhanced rostral grooming activity (i.e., paw licking and head washings) compared to wildtype controls. This data supports the role of serotonin and BDNF in stereotyped behavior, also validating the automated quantification of self‐grooming behavior as an efficient screen for neurobehavioral abnormalities.
Effects of the hallucinogenic drugs mescaline, phencyclidine and psilocybin on zebrafish behavior and physiology
Authors: Kyzar Evan , Collins Christopher , Green Jeremy , Gaikwad Siddharth , Roth Andrew , Monnig Louis , El-Ounsi Mohamed , Capezio Nicholas , Freeman Andrew , Davis Ari , Kalueff Allan
Published: June 2021

Mescaline, phencyclidine (PCP) and psilocybin are potent hallucinogenic drugs strongly affecting both human and animal behavior. However, these compounds have not been previously investigated in zebrafish (Danio rerio), rapidly gaining popularity as a model in psychopharmacology research. Here, we examine the effects of mescaline, PCP and psilocybin in multiple behavioral paradigms. Mescaline (10–20 mg/L) generally displayed an anxiolytic effect in the novel tank test, while PCP (1–3 mg/L) reduced freezing behavior and elicited a pattern of erratic swimming. Mescaline‐treated fish markedly increased shoaling behavior and altered movement patterns in the open field test. Additionally, mescaline and PCP disrupted normal zebrafish exploratory behavior, as assessed by ethograms. Psilocybin at doses tested (0.5–3 mg/L) was inactive in all of the behavioral tests. Interestingly, both psilocybin and PCP raised whole‐body cortisol levels without affecting brain c‐fos expression, and mescaline did not alter cortisol or c‐fos levels. Overall, this confirms the high sensitivity of zebrafish models to various hallucinogenic compounds with complex behavioral and physiological profiles. This study was supported by the National Institute on Drug Abuse (NIDA) R03 grant to AVK.
Chronic LSD administration produces changes in mPFC gene and protein expression relevant to schizophrenia, as determined by RNA‐Seq and DIGE
Authors: Martin David Alexander , Nichols David E , Nichols Charles D
Published: June 2021

The objective of this work is to characterize genetic and proteomic changes in a novel rat model of schizophrenia. Three‐month treatment with low doses of the hallucinogenic drug, LSD, induces a range of abnormal behaviors including social deficits, hyperactivity, and anhedonia. These behavioral changes persist in the absence of drug, and likely result from neuroadaptive changes in the medial prefrontal cortex (mPFC), an area of the brain highly implicated in schizophrenia and in the actions of LSD. DIGE proteomic analysis revealed 12 differentially expresed proteins in the mPFC of LSD‐treated rats, 9 of which have previously been identified as dysregulated in schizophrenic post‐mortem cortex. RNA was sequenced using RNA‐Seq, and bioinformatic analysis of the sequence data reveals that chronic LSD induces alterations in genes for each of the major neurotransmitter systems associated with schizophrenia, as well as other genes associated with this disease. Functional clustering of differentially expressed genes reveals subsets involved in synaptic plasticity are highly represented. This data supports the construct validity of chronic LSD as a new model of schizophrenia, and suggests that further investigation of the effects of LSD may reveal important mechanistic insight into the pathophysiology of schizophrenia, and that our model may be used as a discovery platform. Supported by NIH RO1MH092511.
Tricyclic psychiatric medications as alpha2A adrenergic receptor ligands modulating receptor function
Authors: Cottingham Christopher , Chen Yunjia , Percival Stefanie , Jiao Kai , Wang Qin
Published: June 2021

Neurobiological mechanisms of action underlying psychiatric medications largely remain poorly understood. In this study, we have investigated potential effects of tricyclic drugs on the brain noradrenergic system by characterizing their interactions with and effects on α2A adrenergic receptors (ARs), beginning with the primarily noradrenergic antidepressant desipramine (DMI). DMI was found to be an orthosteric arrestin‐biased ligand at the α2AAR, selectively inducing recruitment of arrestin (observed by FRET) but not activation of heterotrimeric G proteins. Arrestin recruitment results in DMI‐driven downregulation of receptor expression with chronic exposure, a process which occurs for cortical α2AARs in vivo in an arrestin‐dependent fashion and likely underlies mechanistically unexplained neuroadaptive alterations in α2AAR expression associated with DMI. As well, we screened a number of tricyclic antidepressants and antipsychotics as receptor ligands, and found that all tested thus far bind the α2AAR orthosteric site with varying affinities and differing abilities to drive receptor trafficking responses. Our findings provide novel insight into tricyclic pharmacology at α2AARs which could be used to develop novel therapeutic targeting of the noradrenergic system in depressive disorders and schizophrenia. Supported by NIMH grant MH081917 (QW) and NIH T32 training grant NS061788‐03 (CC).
Role of GluN2C‐containing receptors in rodent schizophrenia‐like phenotypes
Authors: Hillman Brandon Geoffrey , Stairs Dustin , Dravid Shashank
Published: June 2021

There are four classes of ionotropic glutamate receptors classified on the basis of sequence similarity and pharmacology. One class of ionotropic glutamate receptors is the N‐methyl‐D‐aspartate (NMDA) receptor, which is composed of two GluN1 and two GluN2 (A–D) subunits. The physiologic role of GluN2C‐containing receptors has remained poorly understood. We have previously shown that GluN2C knockout mice exhibit deficits in fear acquisition and working memory (Hillman et al., 2011) which mimic the negative symptoms and are consistent with the glutamate hypofunction theory of schizophrenia. To further assess a role of GluN2C in schizophrenia‐like behavior we employed genetic and pharmacologic approaches. We found that GluN2C knockout mice were hypersensitive to phencyclidine‐ and social isolation‐induced hyperlocomotion and these results were further explored using the atypical antipsychotic clozapine and a novel potentiator of GluN2C‐containing receptors (CIQ, Mullasseril et al., 2010). Our results suggest that targeting the GluN2C subunit may have therapeutic relevance in schizophrenia.
Cytisine and diarylpropionitrile reduce depressive‐like behavior in female ovx rats
Authors: Walker Makeda , Kandi Praveen , Hayslett Renee
Published: June 2021

Modulation of specific nicotinic acetylcholine receptors (nAChRs) and estrogen receptors (ERs) have been implicated in regulating mood and depressive behavior. In this study we sought to determine whether cytisine and diarylpropionitrile (DPN) reduce depressive characteristics of female rats. Cytisine is a α4β2 nAChR partial agonist and α7 nAChR agonist. DPN is an ERβ agonist. Ovariectomized adult female Sprague Dawley rats (n=8/group) received subcutaneous injections of DPN (0.1 mg/kg) 60 minutes before the forced swim test (FST), cytisine (0.5 mg/kg) 30 minutes before the FST, or the combination. Doses and latencies for drug administration were chosen based on preliminary studies. Controls received corn oil and saline. Locomotor activity was also assessed. Compared to control, acute administration of cytisine or DPN reduced immobility in the FST by 44% and 57%, respectively. The combination of cytisine and DPN reduced immobility compared to control by 82%. No significant differences in locomotor activity were detected. Acute administration of cytisine and DPN significantly decreased immobility in the FST, suggesting an antidepressant‐like effect. Furthermore, the combination of cytisine and DPN produced a greater reduction than either agent administered alone, indicating an additive effect. Supported by Mercer University College of Pharmacy and Health Sciences