scholarly journals Prolonged Withdrawal From Escalated Oxycodone Is Associated With Increased Expression of Glutamate Receptors in the Rat Hippocampus

2021 ◽  
Vol 14 ◽  
Author(s):  
Aaron J. Salisbury ◽  
Christopher A. Blackwood ◽  
Jean Lud Cadet

People suffering from opioid use disorder (OUD) exhibit cognitive dysfunctions. Here, we investigated potential changes in the expression of glutamate receptors in rat hippocampi at 2 h and 31 days after the last session of oxycodone self-administration (SA). RNA extracted from the hippocampus was used in quantitative polymerase chain reaction analyses. Rats, given long-access (9 h per day) to oxycodone (LgA), took significantly more drug than rats exposed to short-access (3 h per day) (ShA). In addition, LgA rats could be further divided into higher oxycodone taking (LgA-H) or lower oxycodone taking (LgA-L) groups, based on a cut-off of 50 infusions per day. LgA rats, but not ShA, rats exhibited incubation of oxycodone craving. In addition, LgA rats showed increased mRNA expression of GluA1-3 and GluN2a-c subunits as well as Grm3, Grm5, Grm6, and Grm8 subtypes of glutamate receptors after 31 days but not after 2 h of stopping the SA experiment. Changes in GluA1-3, Grm6, and Grm8 mRNA levels also correlated with increased lever pressing (incubation) after long periods of withdrawal from oxycodone. More studies are needed to elucidate the molecular mechanisms involved in altering the expression of these receptors during withdrawal from oxycodone and/or incubation of drug seeking.

2020 ◽  
Author(s):  
Aaron J Salisbury ◽  
Christopher A Blackwood ◽  
Jean Lud Cadet

People suffering from opioid use disorder (OUD) exhibit cognitive dysfunctions. Here, we investigated potential changes in the expression of glutamate receptors in rat hippocampi at 2 hours and 31 days after the last session of oxycodone self-administration (SA). RNA extracted from the hippocampus was used in quantitative polymerase chain reaction (qPCR) analyses. Rats, given long-access (9 hours per day) to oxycodone (LgA), took significantly more drug than rats exposed to short-access (3 hours per day) (ShA). In addition, LgA rats could be further divided into higher oxycodone taking (LgA-H) or lower oxycodone taking (LgA-L) groups, based on a cut-off of 50 infusions per day. LgA rats, but not ShA, rats exhibited incubation of oxycodone craving. In addition, LgA rats showed increased mRNA expression of GluA1-3 and GluN2a-c subunits as well as Grm3, Grm5, Grm6 and Grm8 subtypes of glutamate receptors after 31 days but not after 2 hours of stopping the SA experiment. Changes in GluA1-3, Grm6, and Grm8 mRNA levels also correlated with increased lever pressing (incubation) after long periods of withdrawal from oxycodone. More studies are needed to elucidate the molecular mechanisms involved in altering the expression of these receptors during withdrawal from oxycodone and/or incubation of drug seeking.


2020 ◽  
Vol 117 (4) ◽  
pp. 2140-2148 ◽  
Author(s):  
Marsida Kallupi ◽  
Lieselot L. G. Carrette ◽  
Jenni Kononoff ◽  
Leah C. Solberg Woods ◽  
Abraham A. Palmer ◽  
...  

Approximately 25% of patients who are prescribed opioids for chronic pain misuse them, and 5 to 10% develop an opioid use disorder. Although the neurobiological target of opioids is well known, the molecular mechanisms that are responsible for the development of addiction-like behaviors in some but not all individuals are poorly known. To address this issue, we used a unique outbred rat population (heterogeneous stock) that better models the behavioral and genetic diversity that is found in humans. We characterized individual differences in addiction-like behaviors using an addiction index that incorporates the key criteria of opioid use disorder: escalated intake, highly motivated responding, and hyperalgesia. Using in vitro electrophysiological recordings in the central nucleus of the amygdala (CeA), we found that rats with high addiction-like behaviors (HA) exhibited a significant increase in γ-aminobutyric acid (GABA) transmission compared with rats with low addiction-like behaviors (LA) and naive rats. The superfusion of CeA slices with nociceptin/orphanin FQ peptide (N/OFQ; 500 nM), an endogenous opioid-like peptide, normalized GABA transmission in HA rats. Intra-CeA levels of N/OFQ were lower in HA rats than in LA rats. Intra-CeA infusions of N/OFQ (1 μg per site) reversed the escalation of oxycodone self-administration in HA rats but not in LA rats. These results demonstrate that the downregulation of N/OFQ levels in the CeA may be responsible for hyper-GABAergic tone in the CeA that is observed in individuals who develop addiction-like behaviors. Based on these results, we hypothesize that small molecules that target the N/OFQ system might be useful for the treatment of opioid use disorder.


Parasite ◽  
2019 ◽  
Vol 26 ◽  
pp. 9 ◽  
Author(s):  
Thouraya Boussoffara ◽  
Mohamed Samir Boubaker ◽  
Melika Ben Ahmed ◽  
Mourad Mokni ◽  
Ikram Guizani ◽  
...  

Lesion features in cutaneous leishmaniasis (CL) depend on the infecting Leishmania species as well as on host immune reponse. In this study, we evaluated the histological and immunological differences between two forms of CL described in Tunisia: zoonotic cutaneous leishmaniasis (ZCL) caused by L. major and sporadic cutaneous leishmaniasis (SCL) caused by L. infantum. Histological analysis showed a mild to moderate infiltrate within ZCL lesions. In contrast, massive infiltration of the dermis was observed within SCL lesions. Contrary to ZCL, infiltrates within SCL lesions were organized and showed granuloma composed of macrophages and lymphocytes. In addition, immunohistochemical analysis showed a predominance of CD4+ T cells within both CL forms. Furthermore, expression of interferon-γ, interleukin (IL)-10, IL-8, IL-13 and monocyte chemotactic protein (MCP)-1 was evaluated using real-time quantitative polymerase chain reaction (RT-qPCR). MCP-1 and IL-10 were expressed at comparable levels in ZCL and SCL lesions. Interestingly, IL-8 mRNA levels were significantly higher in ZCL lesions compared to SCL lesions, but interferon-γ was significantly higher in SCL lesions than in ZCL lesions.


2021 ◽  
Author(s):  
Carter Allen ◽  
Brittany N Kuhn ◽  
Nazzareno Cannella ◽  
Ayteria D Crow ◽  
Analyse T Roberts ◽  
...  

Opioid use disorder is a psychological condition that affects over 200,000 people per year in the U.S., causing the Centers for Disease Control and Prevention to label the crisis as a rapidly spreading public health epidemic. It has been found that the behavioral relationship between opioid exposure and development of opioid use disorder varies greatly between individuals, implying existence of sup-populations with varying degrees of opioid vulnerability. In this study, we assessed several behavioral variables across heroin taking, refraining and seeking to establish how these factors interact with one another resulting in a heroin dependent, resilient, or vulnerable behavioral phenotype. Over 400 (male and female) heterogeneous stock rats were used in these two studies, and data were collected from two geographically distinct locations. Rats underwent heroin self-administration training, followed by a progressive ratio and heroin-primed reinstatement test. Next, rats underwent extinction training and a cue-induced reinstatement test. To assess how these variables contribute to heroin addiction vulnerability, we developed a network-based data analysis workflow. Specifically, we integrated different cohorts of rats, remove possible batch effects, and constructed a rat-rat similarity network based on their behavioral patterns. We then implemented community detection on this similarity network using a Bayesian degree-corrected stochastic block model to uncover sub-populations of rats with differing levels of opioid vulnerability. We discovered three distinct behavioral sub-populations, each with significantly different behavioral outcomes that allowed for unique characterization of each cluster in terms of vulnerability to opioid use and seeking. We implement this analysis workflow as an open source R package, named mlsbm.


2021 ◽  
Vol 12 ◽  
Author(s):  
Carter Allen ◽  
Brittany N. Kuhn ◽  
Nazzareno Cannella ◽  
Ayteria D. Crow ◽  
Analyse T. Roberts ◽  
...  

Opioid use disorder is a psychological condition that affects over 200,000 people per year in the U.S., causing the Centers for Disease Control and Prevention to label the crisis as a rapidly spreading public health epidemic. The behavioral relationship between opioid exposure and development of opioid use disorder (OUD) varies greatly between individuals, implying existence of sup-populations with varying degrees of opioid vulnerability. However, effective pre-clinical identification of these sub-populations remains challenging due to the complex multivariate measurements employed in animal models of OUD. In this study, we propose a novel non-linear network-based data analysis workflow that employs seven behavioral traits to identify opioid use sub-populations and assesses contributions of behavioral variables to opioid vulnerability and resiliency. Through this analysis workflow we determined how behavioral variables across heroin taking, refraining and seeking interact with one another to identify potentially heroin resilient and vulnerable behavioral sub-populations. Data were collected from over 400 heterogeneous stock rats in two geographically distinct locations. Rats underwent heroin self-administration training, followed by a progressive ratio and heroin-primed reinstatement test. Next, rats underwent extinction training and a cue-induced reinstatement test. To enter the analysis workflow, we integrated data from different cohorts of rats and removed possible batch effects. We then constructed a rat-rat similarity network based on their behavioral patterns and implemented community detection on this similarity network using a Bayesian degree-corrected stochastic block model to uncover sub-populations of rats with differing levels of opioid vulnerability. We identified three statistically distinct clusters corresponding to distinct behavioral sub-populations, vulnerable, resilient and intermediate for heroin use, refraining and seeking. We implement this analysis workflow as an open source R package, named mlsbm.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jianming Sun ◽  
Linggang Deng ◽  
Ye Gong

Prostate cancer (PCa) is a common malignant tumor of the male genitourinary system that seriously affects the quality of life of patients. Studying the pathogenesis and therapeutic targets of PCa is important. In this study, we investigated the role of miR-145-5p in PCa and its potential molecular mechanisms. The expression levels of miR-145-5p in PCa tissues and adjacent control tissues were detected by real-time quantitative polymerase chain reaction. The effects of miR-145-5p overexpression on PCa were studied using cell proliferation, migration, and invasion experiments. Furthermore, WIP1 was the target gene of miR-145-5p through the bioinformatics website and dual-luciferase reporter gene experiment. Further studies found that WIP1 downregulation could inhibit the proliferation, invasion, and cloning of PCa cells. Overexpression of WIP1 reversed the anticancer effects of miR-145. The anticancer effect of miR-145 was achieved by inhibiting the PI3K/AKT signaling pathway and upregulating ChK2 and p-p38MAPK. Taken together, these results confirmed that miR-145-5p inhibited the growth and metastasis of PCa cells by inhibiting the expression of proto-oncogene WIP1, thereby playing a role in tumor suppression in PCa and may become a potential therapeutic target for the treatment of PCa.


2020 ◽  
Vol 32 (11) ◽  
pp. 976
Author(s):  
Monica De los Reyes ◽  
Jaime Palomino ◽  
Carola Gallegos ◽  
Roberto Espinoza ◽  
Phillipe Dettleff ◽  
...  

The aim of this study was to evaluate the expression of connexin (Cx) 37 and Cx43 in canine cumulus–oocyte complexes (COCs) during the oestrous cycle. Cx localisation was analysed by immunohistochemistry and immunofluorescence, whereas protein and gene expression was evaluated by western blotting and quantitative polymerase chain reaction respectively; comparisons were made using analysis of variance. Both Cx37 and Cx43 were expressed in all follicular stages; Cx43 was identified in cumulus cells and Cx37 was identified in cumulus cells, zonae pellucida and oocytes. Immunofluorescence analyses showed that Cx37 remained unchanged during the preovulatory stage but decreased after ovulation, whereas Cx43 remained unchanged before and after ovulation. Cx43 transcripts increased (P<0.05) during anoestrus and dioestrus in medium-sized follicles but remained unaltered during the pro-oestrus and antral stages during oestrus, before and after ovulation. Cx37 mRNA levels decreased in ovulated COCs (P<0.05). The highest levels of Cx37 protein (P<0.05) were detected in the preantral stage during anoestrus. In contrast, strong Cx43 signals were detected in oestrus and in medium-sized antral follicles in dioestrus (P<0.05). Overall, we demonstrated that Cx37 and Cx43 exhibit different expression patterns, suggesting specific roles throughout growth. Maintenance of Cx expression before ovulation indicates the involvement of Cx37 and Cx43 in the prolonged meiotic arrest.


Blood ◽  
2007 ◽  
Vol 110 (7) ◽  
pp. 2324-2330 ◽  
Author(s):  
Julie Bergeron ◽  
Emmanuelle Clappier ◽  
Isabelle Radford ◽  
Agnès Buzyn ◽  
Corinne Millien ◽  
...  

TLX1 is a homeodomain transcription factor generally associated with a favorable outcome in T-cell acute lymphoblastic leukemia (T-ALL). However, the molecular mechanisms of TLX1 deregulation remain unclear and various transcript levels in the absence of 10q24 abnormalities have been reported. A reproducible and accurate delineation of TLX1+ T-ALL will be necessary for proper therapeutic stratification. We have studied 264 unselected T-ALLs (171 adults and 93 children) and show that T-ALLs expressing high levels of TLX1 (n = 35, 13%), defined as a real-time quantitative polymerase chain reaction (RQ-PCR) level of TLX1 greater than 1.00 ABL, form a homogeneous oncogenic group, based on their uniform stage of maturation arrest and oncogenetic and transcriptional profiles. Furthermore, TLX1-high T-ALLs harbor molecular TLX1 locus abnormalities in the majority (31/33), a proportion largely underestimated by standard karyotypic screening. T-ALLs expressing TLX1 at lower levels (n = 57, 22%) do not share these characteristics. Prognostic analysis within the adult LALA94 and GRAALL03 prospective protocols demonstrate a better event-free survival (P = .035) and a marked trend for longer overall survival (P = .059) for TLX1-high T-ALLs, while the expression of lower levels of TLX1 does not impact on prognosis. We propose that TLX1+ T-ALLs be defined as cases expressing TLX1/ABL ratios greater than 1 and/or demonstrating TLX1 rearrangement. Therapeutic modification should be considered for those patients.


1992 ◽  
Vol 22 (5) ◽  
pp. 1179-1184 ◽  
Author(s):  
Cornelia Platzer ◽  
Günther Richter ◽  
Klaus Überla ◽  
Werner Müller ◽  
Helmut Blöcker ◽  
...  

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