Isolation, identification, and pathogenicity of Pseudomonas glycinae causing ginseng bacterial soft rot in China.

By tissue separation method, tie-back experiment, and hypersensitive response test in potato, strain XJFL-1 was isolated and identified as the pathogen of ginseng bacterial soft rot in Liaoning Provence, China. The morphological characteristics of XJFL-1 were conformed to the Pseudomonads genus. Microbial fatty acid identification showed the principal cellular fatty acid traits of XLFJ-1 corresponded with Pseudomonas spp. API 50CH test results allowed the differentiation of strain XJFL-1 and MS586T from other closely related Pseudomonas species. The molecular identification, including 16S rRNA analysis and multilocus sequence typing (MLST) analysis, showed that XJFL-1 was in the same branch as P. glycinae MS586T. The genome of XJFL-1 was 6,296,473 bp, with an average guanine/cytosine (G + C) content of 60.72 %. Comparative genomics analysis using ANIb and GGDC algorithms indicated that the maximum value was observed between XJFL-1 and P. glycinae MS586T. The above morphological, cell morphology, and molecular biological identification results supported to identification of XJFL-1 as P. glycinae. This is the first report of P. glycinae as the plant pathogen causing ginseng bacterial root rot in China, which complements the biological significance of the species to a certain extent, enriches the pathogens of ginseng bacterial soft rot, and provides a theoretical basis for further investigation.

Triggering Receptor Expressed on Myeloid Cells 2 Deficiency Exacerbates Methamphetamine-Induced Activation of Microglia and Neuroinflammation.

Methamphetamine (METH) is a highly addictive psychostimulant and one of the most widely abused drugs worldwide. The continuous use of METH eventually leads to neurotoxicity and drug addiction. Studies have shown that neurotoxicity is strongly associated with METH-induced neuroinflammation, and microglia are the key drivers of neuroinflammation. Triggering receptor expressed on myeloid cells 2 (TREM2) is reported to play a key role in activation of microglia and neuroinflammation. Yet, the molecular mechanisms by which METH causes neuroinflammation and neurotoxicity remain elusive. In the current study, we investigated the role of TREM2 in neuroinflammation induced by METH in BV2 cells and the wild-type (WT) C57BL/6J mice, CX3CR1GFP/+ transgenic mice, and TREM2 knockout (KO) mice. Postmortem samples from the frontal cortex of humans with a history of METH use were also analyzed to determine the levels of TREM2, TLR4, IBA1, and IL-1ß. The expression levels of TREM2, TLR4, IBA1, IL-1ß, iNOS, and Arg-1 were then assessed in the BV2 cells and frontal cortex of mice and human METH users. Results revealed that the expression levels of TREM2, TLR4, IBA1, and IL-1ß were significantly elevated in METH-using individuals and BV2 cells. Microglia were clearly activated in the frontal cortex of WT C57BL/6 mice and CX3CR1GFP/+ transgenic mice, and the protein levels of IBA1, TREM2, TLR4, and IL-1ß were elevated in the METH-induced mouse models. Moreover, TREM2-KO mice showed further increased microglial activation, neuroinflammation, and excitotoxicity induced by METH. Thus, these findings suggest that TREM2 may be a target for regulating METH-induced neuroinflammation.

First report of root rot caused by Fusarium commune on American ginseng (Panax quinquefolium L.) in China.

American ginseng (Panax quinquefolium L.) is one of the most valuable herb crops because of its unique pharmacological effects. In 2019, American ginseng plants withered and root rot with incidences of 20-45% were observed in about 70000m2 of ginseng production field located in mountainous valley of Benxi city (41º23'32" N, 124º04'27" E), Liaoning Province in China. Disease symptoms included chlorotic leaves with dark brown discoloration extending gradually from the basal to the apical part of the leaves. Water-soaked, irregular lesions appeared on the surface of roots and rotten at later stage. Twenty-five symptomatic roots were surface-sterilized by immersion in 2% sodium hypochlorite (NaOCl) for 3 min, followed by rinsing three times in sterilized water. The sections healthy tissues bordered rotten tissues, i.e. the leading edge, were cut into 4-5 mm pieces with a sterile scalpel and 4 pieces were placed on each PDA plate. After 5 days incubation at 26°C, total of 68 single spores were obtained from the colonies with an inoculation needle under stereomicroscope. Colonies from single conidia were white to greyish white, densely floccose to fluffy, and the reverse grayish yellow with dull violet pigmentation. Single-celled and ovoid microconidia in false heads were borne on aerial monophialidic or polyphialidic conidiophores on Carnation Leaf Agar (CLA) media, and measured 5.0 -14.5 × 3.0 -4.8 µm (n=25). Macroconidia were two to four septa, slightly curved, apical and basal cells were also curved, and they measured 22.5 - 45.5 × 4.5 - 6.3 µm (n=25). Chlamydospores were singly or in pairs, circular or subcircular, smooth, and measuring 5 - 10.5 µm (n=25) in diameter. Morphologically, the isolates were identified as Fusarium commune (Skovgaard et al. 2003; Leslie and Summerell 2006 ). To confirm the identity, the rDNA partial translation elongation factor1 alpha (TEF-a) gene and the internal transcribed spacer (ITS) region of ten isolates were amplified and sequenced (O'Donnell et al. 2015; White et al. 1990). Identical sequences were obtained, and one representative sequence of isolate BGL68 was submitted to GenBank. BLASTn analysis of both the TEF-α (MW589548) and the ITS (MW584396) sequences, revealed 100% and 99.46 % sequence identity to F. commune MZ416741 and KU341322, respectively. The pathogenicity test was conducted under greenhouse conditions. The surface of healthy 2-year-old American ginseng roots was washed and disinfested in 2% NaOCl for 3 min before rinsing in sterilized water. Twenty roots were wounded with a toothpick, resulting in tiny perforations (1.0 × 1.0×3.0 mm), 3 perforations were wounded on each root. Inoculums was prepared from the culture of isolate BGL68 incubate in potato dextrose broth (PD) for 5 days at 26°C,140 rpm. Ten wounded roots were immersed in a conidial suspension (2 × 105 conidia/ml) for four hours in a plastic bucket, and planted in five containers (two roots per container) filled with sterile soil. Another ten wounded roots were immersed in sterilized distilled water and planted in five containers as controls. The containers were incubated for four weeks in a greenhouse at temperature between 23°C and 26°C, under a 12-hr light and dark regime, and irrigate with sterile water every 4 days. Three weeks after inoculation, all inoculated plants exhibited chlorotic leaves, wilting and root rot. The taproot and the fibrous roots showed brown to black root rot and no symptoms in non-inoculated controls. The fungus was reisolated from the inoculated plants, but not from any of the control plants. The experiment was repeated two times with similar results. This is the first report of root rot caused by F. commune on American ginseng in China. The disease might bring a threat to this ginseng production and should be implemented effective control measures to reduce losses.

First report of Fusarium oxysporum causing root rot of Gentiana scabra bunge (Adenophora capillaris) in China.

Gentiana scabra bunge (Adenophora capillaris) is a traditional Chinese medicine crop in the northeast China. In July 2019, the root rot symptoms of A. capillaris were observed in its production field (approximately 1.3 hectares) iningyuan Manchu Autonomous County (41º47'28" N, 124º21'35" E), Fushun City in Liaoning province, China. Typical symptom included wilting, darkening, and rotting of the root collar and vascular bundle, leading to plant defoliation and death. Approximately 25% of the plants in the field showed the symptoms, with 2-year-old plants having more severe symptoms. Root tissue samples were collected from the diseased plants, surface-sterilized with 75% ethanol for 30 s, followed by 2% NaClO for 5 min, rinsed three times in sterile distilled water, and plated onto potato dextrose agar (PDA). After 3 days of incubation at 25 °C, white Fusarium-like colonies grew out from the symptomatic root tissue pieces. Five single-spore isolates were obtained from 10-day-old cultures using single-spore isolating technique. The fungus produced many macroconidia with the typical macroconidia of Fusarium spp. on carnation leaf agar (CLA) after 18 days of incubation at 26°C. They were falculate, slender and slightly curved, and their cells at both ends were sharp. Macroconidia had 3 to 5 septa, measuring 24.8 to 48.6 × 3.5 to 6.4 µm (n=50). Microconidia had 1 to 2 septa, elliptical, rounded tip, measuring 6.7 to 22.5 × 2.4 to 5.5 µm (n=5). Morphologically, the isolates were identified as Fusarium oxysporum (Leslie and Summerell 2006). For molecular identification, the internal transcribed spacer (ITS) region of rDNA and the translation elongation factor-1a (TEF-1α) of Isolate LD528-1 were amplified with the general primer ITS1/ITS4 and TEF-1α primer EF-1/EF-2 (O'Donnell et al. 1998). The resulting sequences were deposited in GenBank (acc. nos. MW418098 and MW423622). BLASTn analysis of the ITS sequence (KU939043) and TEF sequence (MW423622) revealed 99.06% sequence identity with F. oxysporum (KU939043) and 100% with F. oxysporum (MN892354), respectively. For pathogenicity test, a pot experiment was conducted in a greenhouse with 22 to 28°C and 65 to 90% relative humidity. Roots of A. capillaris were dipped in a spore suspension (1×107 conidia/ml) of Isolate LD528-1 for approximately 5 min, and then planted into the pots filled with sterilized field soil. Root dipped in sterilized water served as the controls. There were five pots for the inoculation treatment and three pots for the control treatment. All treated pots were placed and maintained in the greenhouse. After 15 days, 80% of inoculated plants were infected, with the symptoms similar to those observed in the field. The plants in the control treatment did not develop any symptoms. The same fungus was re-isolated from the diseased root tissue and confirmed by morphological and molecular assays as described above. This is the first report of F. oxysporum causing root rot of gentiana scabra bunge in China. This disease can become one of most important diseases in gentiana scabra bunge in China. References: Leslie, J. F., and Summerell, B. A. 2006. The Fusarium Laboratory Manual. Blackwell Publishing Ltd, Iowa, USA. O'Donnell, K., et al. 1998.PNAS, 95:2044. Funding: This work was supported by the Grant of China Agriculture Research System (CARS-21-06).

Current Situation of Methamphetamine Abuse and Related Research Progress.

Drug problem is a major social and public security problem in the world. Drug abuse poses a great threat to economic development, social stability and public health. In recent years, synthetic drugs represented by methamphetamine have surpassed traditional drugs such as morphine, heroin, ketamine and become one of the most abused drugs in the world. In order to solve the problem of drug abuse, it is of great theoretical value and practical significance to carry out all-round and multi-level scientific research on drug-related issues. Based on the current situation of drug abuse, this article reviews research progresses on the epidemiology of methamphetamine abuse, the monitoring technology, the basic researches on toxicity damage, the withdrawal drug screening, the related clinical comorbidity and the testing technologies, comprehensively presenting the development trend of methamphetamine abuse related issues.

Nrf2 protects against methamphetamine-induced nephrotoxicity by mitigating oxidative stress and autophagy in mice.

Methamphetamine (MA) is a widely abused drug that can cause kidney damage. However, the molecular mechanism remains unclear. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a key transcription factor that regulates resistance to oxidative and proteotoxic stress. In this study, we investigated the role of Nrf2 in MA-induced renal injury in mice. Nrf2 was pharmacologically activated and genetically knocked-out in mice. The animal model of MA-induced nephrotoxicity was established by injecting MA (2 mg/kg) intraperitoneally twice a day for 5 days. Histopathological alterations were shown in the MA-exposed kidneys. MA significantly increased renal function biomarkers and kidney injury molecule-1 (KIM-1) levels. MA decreased superoxide dismutase activity and increased malondialdehyde levels. Autophagy-related factors (LC3 and Beclin 1) were elevated in MA-treated mice. Furthermore, Nrf2 increased in the MA-exposed kidneys. Activation of Nrf2 may attenuate histopathological changes in the kidneys of MA-treated mice. Pre-administration of Nrf2 agonist significantly decreased KIM-1 expression, oxidative stress, and autophagy in the kidneys after MA toxicity. In contrast, Nrf2 knockout mice treated with MA lost renal tubular morphology. Nrf2 deficiency increased KIM-1 expression, oxidative stress, and autophagy in the MA-exposed kidneys. Our results demonstrate that Nrf2 may protect against MA-induced nephrotoxicity by mitigating oxidative stress and autophagy.

Corrigendum to "Ginsenoside Rb1 attenuates methamphetamine (METH)-induced neurotoxicity through the NR2B/ERK/CREB/BDNF signalings in vitro and in vivo models" [J Ginseng Res 46 (2022) 426-434].

[This corrects the article DOI: 10.1016/j.jgr.2021.07.005.].

Nrf2 attenuates methamphetamine-induced myocardial injury by regulating oxidative stress and apoptosis in mice.

OBJECTIVES: Methamphetamine (MA) abuse is a serious social problem worldwide. Cardiovascular complications were the second leading cause of death among MA abusers. We aimed to clarify the effects of MA on myocardial injury, oxidative stress, and apoptosis in myocardial cells and to explore the potential mechanism of nuclear factor-erythroid factor 2-related factor 2 (Nrf2) in MA-induced oxidative stress and apoptosis. METHODS: An acute cardiac toxicity model of MA was established by intraperitoneal injection of MA (2 mg/kg) for 5 days. Nrf2 activation (by sulforaphane (SFN) 1 h before MA injection) and Nrf2 gene knockout were performed to explore the regulatory effects of Nrf2 on cardiac toxicity. RESULTS: The protein expressions of Nrf2 (p < .001) and heme oxygenase-1 (HO-1) were increased (p < .01), suggesting that MA activated the Nrf2/HO-1 pathway. In the MA group, cardiac injury score (p < .001) and cardiac troponin I (cTnI) protein expression increased (p < .01). Malondialdehyde (MDA) content increased (p < .001), superoxide dismutase (SOD) activity decreased (p < .05). Protein expressions of Caspase-3 (p < .001) and Bax (p < .001) increased, and Bcl-2 decreased (p < .001) as well. These changes were reversed by activation of Nrf2 but became more pronounced after Nrf2 knockout, suggested that the activation and knockout of Nrf2 attenuated and aggravated MA-induced myocardial injury, oxidative stress and apoptosis in myocardial cells, respectively. CONCLUSIONS: MA administration induced myocardial injury, oxidative stress, and apoptosis in mice. Nrf2 attenuated MA-induced myocardial injury by regulating oxidative stress and apoptosis, thus playing a protective role.

Cannabidiol inhibits methamphetamine-induced dopamine release via modulation of the DRD1-MeCP2-BDNF-TrkB signaling pathway.

RATIONALE: Adaptive alteration of dopamine (DA) system in mesocorticolimbic circuits is an extremely intricate and dynamic process, which contributes to maintaining methamphetamine (METH)-related disorders. There are no approved pharmacotherapies for METH-related disorders. Cannabidiol (CBD), a major non-psychoactive constituent of cannabis, has received attention for its therapeutic potential in treating METH-related disorders. However, the major research obstacles of CBD are the yet to be clarified mechanisms behind its therapeutic potential. Recent evidence showed that DA system may be active target of CBD. CBD could be a promising dopaminergic medication for METH-related disorders. OBJECTIVES: We investigated the role of the DA receptor D1 (DRD1)-methyl-CpG-binding protein 2 (MeCP2)-brain-derived neurotrophic factor (BDNF)-tyrosine receptor kinase B (TrkB) signaling pathway in DA release induced by METH. Investigating the intervention effects of CBD on the DRD1-MeCP2-BDNF-TrkB signaling pathway could help clarify the underlying mechanisms and therapeutic potential of CBD in METH-related disorders. RESULTS: METH (400 µM) significantly increased DA release from primary neurons in vitro, which was blocked by CBD (1 µM) pretreatment. METH (400 µM) significantly increased the expression levels of DRD1, BDNF, and TrkB, but decreased the expression of MeCP2 in the neurons, whereas CBD (1 µM) pretreatment notably inhibited the protein changes induced by METH. In addition, DRD1 antagonist SCH23390 (10 µM) inhibited the DA release and protein change induced by METH in vitro. However, DRD1 agonist SKF81297 (10 µM) induced DA release and protein change in vitro, which was also blocked by CBD (1 µM) pretreatment. METH (2 mg/kg) significantly increased the DA level in the nucleus accumbens (NAc) of rats with activation of the DRD1-MeCP2-BDNF-TrkB signaling pathway, but these changes were blocked by CBD (40 or 80 mg/kg) pretreatment. CONCLUSIONS: This study indicates that METH induces DA release via the DRD1-MeCP2-BDNF-TrkB signaling pathway. Furthermore, CBD significantly inhibits DA release induced by METH through modulation of this pathway.

Cannabidiol attenuates methamphetamine-induced cardiac inflammatory response through the PKA/CREB pathway in rats.

Background: Methamphetamine (MA) abuse is a major global public health problem. However, it is not yet known whether cannabidiol (CBD) has protective effects on MA-induced cardiotoxicity. The present study investigated whether CBD has protective effects on MA-induced cardiac damage in rats via the protein kinase A/cyclic adenosine monophosphate (cAMP)-response element-binding protein (PKA/CREB) pathway. Methods: A total of 30 rats were randomly divided into 5 groups. The rats were administered MA (10 mg/kg) by intraperitoneal (IP) injection once a day for 4 weeks, and with CBD (40 or 80 mg/kg, IP) treatment 1 h before the MA injections. Morphological changes were determined using hematoxylin and eosin and Masson's trichrome staining. The serum levels of interleukin (IL)-6 and IL-10 were detected using enzyme-linked immunoassay kits. The protein expression levels of cardiac troponin I (cTnI), PKA, phospho-PKA (p-PKA), CREB, and phospho-CREB (p-CREB) in the myocardium were detected by Western blot analysis. Results: There was no significant difference in body weight among the groups. Heart weight and the heart-to-body weight ratio were higher in the MA group than the control group, while CBD (80 mg/kg) pretreatment (CBD80 + MA group) reduced the heart weight and the heart-to-body weight ratio compared to the MA group. The chronic administration of MA resulted in a cardiac inflammatory response, the progressive development of fibrosis, and necrosis, while CBD treatment attenuated these lesions. The protein expression levels of PKA, p-PKA, CREB, and p-CREB increased following MA administration, but significantly decreased with CBD treatment. These results indicate that chronic MA administration leads to cardiotoxicity, but these effects can be attenuated by CBD pretreatment. Conclusions: This study was the first to examine the protective effects of CBD on cardiotoxicity elicited by chronic MA exposure in rats. Our research suggests that CBD attenuates the cardiac inflammatory response induced by MA through the PKA/CREB pathway, and CBD may have potential clinical application in the treatment of MA-induced cardiotoxicity.

Ginsenoside Rb1 attenuates methamphetamine (METH)-induced neurotoxicity through the NR2B/ERK/CREB/BDNF signalings in vitro and in vivo models.

Aim: This study investigates the effects of ginsenoside Rb1 (GsRb1) on methamphetamine (METH)-induced toxicity in SH-SY5Y neuroblastoma cells and METH-induced conditioned place preference (CPP) in adult Sprague-Dawley rats. It also examines whether GsRb1 can regulate these effects through the NR2B/ERK/CREB/BDNF signaling pathways. Methods: SH-SY5Y cells were pretreated with GsRb1 (20 µM and 40 µM) for 1 h, followed by METH treatment (2 mM) for 24 h. Rats were treated with METH (2 mg/kg) or saline on alternating days for 10 days to allow CPP to be examined. GsRb1 (5, 10, and 20 mg/kg) was injected intraperitoneally 1 h before METH or saline. Western blot was used to examine the protein expression of NR2B, ERK, P-ERK, CREB, P-CREB, and BDNF in the SH-SY5Y cells and the rats' hippocampus, nucleus accumbens (NAc), and prefrontal cortex (PFC). Results: METH dose-dependently reduced the viability of SH-SY5Y cells. Pretreatment of cells with 40 µM of GsRb1 increased cell viability and reduced the expression of METH-induced NR2B, p-ERK, p-CREB and BDNF. GsRb1 also attenuated the expression of METH CPP in a dose-dependent manner in rats. Further, GsRb1 dose-dependently reduced the expression of METH-induced NR2B, p-ERK, p-CREB, and BDNF in the PFC, hippocampus, and NAc of rats. Conclusion: GsRb1 regulated METH-induced neurotoxicity in vitro and METH-induced CPP through the NR2B/ERK/CREB/BDNF regulatory pathway. GsRb1 could be a therapeutic target for treating METH-induced neurotoxicity or METH addiction.

Methamphetamine and HIV-1 Tat proteins synergistically induce microglial autophagy via activation of the Nrf2/NQO1/HO-1 signal pathway.

Methamphetamine (METH) is a psychostimulant that is abused throughout the world. METH is a highly addictive drug commonly used by persons living with HIV, and its use can result in cognitive impairment and memory deficits. METH and human immunodeficiency virus-1 transactivator of transcription (HIV-1Tat) have toxic and synergistic effects on the nervous system; however, the mechanism of their synergistic effects has not been clarified. We used BV2 cells, primary microglia, Nrf2-KO C57BL/6J mice, and autopsied brain tissues of METH-abusing, HIV infection, and METH-abusing individuals comorbid with HIV to explore the regulatory role of Nrf2/NQO1/HO-1 signal pathway on microglia autophagy. Our results showed that microglia were significantly activated by METH and HIV-1Tat protein. METH and HIV-1Tat protein combination significantly increase the autophagy-related proteins (LC3-II, Beclin-1, ATG5, and ATG7) expression in microglia and striatum of C57BL/6J mice. After silencing or knocking out the Nrf2 gene, the expression levels of autophagy-related proteins were significantly increased. In human brain tissue, microglia were activated, Nrf2, LC3-II, and Beclin-1 expression levels were raised, and the p62 expression level was decreased. Our results suggested that METH and HIV or HIV-1Tat synergistically affect autophagy. And the Nrf2 pathway plays a vital role in regulating the synergistic induction of microglial autophagy by METH and HIV-1Tat protein. This study may provide a theoretical basis and new ideas for effective targets for pharmacological intervention in HIV-infected patients with drug abuse.

Cannabidiol prevents methamphetamine-induced neurotoxicity by modulating dopamine receptor D1-mediated calcium-dependent phosphorylation of methyl-CpG-binding protein 2.

In the past decade, methamphetamine (METH) abuse has sharply increased in the United States, East Asia, and Southeast Asia. METH abuse not only leads to serious drug dependence, but also produces irreversible neurotoxicity. Currently, there are no approved pharmacotherapies for the treatment of METH use disorders. Cannabidiol (CBD), a major non-psychoactive (and non-addictive) cannabinoid from the cannabis plant, shows neuroprotective, antioxidative, and anti-inflammatory properties under METH exposure. At present, however, the mechanisms underlying these properties remain unclear, which continues to hinder research on its therapeutic potential. In the current study, computational simulations showed that CBD and METH may directly bind to the dopamine receptor D1 (DRD1) via two overlapping binding sites. Moreover, CBD may compete with METH for the PHE-313 binding site. We also found that METH robustly induced apoptosis with activation of the caspase-8/caspase-3 cascade in-vitro and in-vivo, while CBD pretreatment prevented these changes. Furthermore, METH increased the expression of DRD1, phosphorylation of Methyl-CpG-binding protein 2 (MeCP2) at serine 421 (Ser421), and level of intracellular Ca2+ in-vitro and in-vivo, but these effects were blocked by CBD pretreatment. The DRD1 antagonist SCH23390 significantly prevented METH-induced apoptosis, MeCP2 phosphorylation, and Ca2+ overload in-vitro. In contrast, the DRD1 agonist SKF81297 markedly increased apoptosis, MeCP2 phosphorylation, and Ca2+ overload, which were blocked by CBD pretreatment in-vitro. These results indicate that CBD prevents METH-induced neurotoxicity by modulating DRD1-mediated phosphorylation of MeCP2 and Ca2+ signaling. This study suggests that CBD pretreatment may resist the effects of METH on DRD1 by competitive binding.

Cannabidiol attenuates methamphetamine-induced conditioned place preference via the Sigma1R/AKT/GSK-3ß/CREB signaling pathway in rats.

Methamphetamine (METH) is a highly addictive psychostimulant. Cannabidiol (CBD) is an exogenous cannabinoid without psychostimulating activity, which has potential therapeutic effects on opioid addiction. However, it is unclear whether CBD has therapeutic effects on METH-induced motivational effects. The present study examines whether CBD has a protective effect on METH-induced conditioned place preference (CPP) in rats by regulating the Sigma1R and AKT-GSK3ß-CREB signaling pathway. Seventy rats were equally and randomly divided into seven groups. The rat CPP model was established via the intraperitoneal injection (IP) of 2 mg/kg of METH. Next, the intraperitoneal injection of 10, 20, 40, and 80 mg/kg CBD was performed 1 h prior to the injection of saline or METH. The protein expression levels of Sigma1R, AKT, p-AKT, GSK-3ß, p-GSK-3ß, CREB, and p-CREB in the rats' prefrontal cortex, nucleus accumbens, and hippocampus and ventral tegmental were detected using western blot analysis. CBD was found to inhibit METH-induced CPP in a dose-dependent fashion. The expression levels of Sigma1R, p-AKT, p-GSK3ß, and p-CREB increased significantly in the METH-induced CPP model. Treatment involving different doses of CBD caused differential inhibitory responses in the cellular protein abundance of Sigma1R, p-AKT, p-GSK3ß, and p-CREB across various brain regions. The present study found that METH can induce CPP in rats. When a pretreatment of CBD is applied, the CBD can weaken CPP in METH-induced rats by regulating the SigmaR1/AKT/GSK-3ß/CREB signaling pathway. The results of this study indicate that CBD has a potential therapeutic effect on METH-induced rewarding effects.

Erratum to: Cannabidiol attenuates methamphetamine-induced conditioned place preference via the Sigma1R/AKT/GSK-3ß/CREB signaling pathway in rats.

[This corrects the article DOI: 10.1093/toxres/tfaa021.].

Involvement of dopamine D3 receptor and dopamine transporter in methamphetamine-induced behavioral sensitization in tree shrews.

INTRODUCTION: This study aims to establish a methamphetamine (METH)-induced behavioral sensitization model using tree shrews, as well as to measure the protein expression of the dopamine D3 receptor (D3R) and dopamine transporter (DAT). METHODS: Forty tree shrews were equally and randomly divided into four experimental groups: those administered with 1, 2, and 4 mg/kg METH and a control group (treated with an equal amount of normal saline). Each experimental group was repeatedly exposed to METH for nine consecutive days to induce the development of behavioral sensitization, followed by four days of withdrawal (without the METH treatment) to induce the transfer of behavioral sensitization, then given 0.5 mg/kg of METH to undergo the expression of behavioral sensitization. Altered locomotor and stereotypic behaviors were measured daily via open-field experiments during the development and expression stages, and weight changes were also recorded. Then, the Western blot method was used to detect the expression levels of D3R and DAT in three brain regions: the nucleus accumbens, prefrontal cortex, and dorsal striatum 24 hr after the last behavioral test. RESULTS: METH administration augmented motor-stimulant responses and stereotypic behaviors in all experimental groups, and stereotypic behaviors intensified more in the groups treated with 2 and 4 mg/kg METH. Motion distance, speed, and trajectory were significantly elevated in all experimental, however, METH at 4 mg/kg induced more stereotypic behaviors, decreasing these locomotor activities as compared with the 2 mg/kg METH group. 2 and 4 mg/kg METH significantly upregulated and downregulated D3R and DAT expression levels, respectively, in three brain regions, and these changes are more pronounced in 2 mg/kg METH. CONCLUSIONS: These results indicated that this animal model may be used to study the neurobiological mechanisms that underly the development and expression of behavioral sensitization to METH. Deregulated D3R and DAT expression may be involved in the METH-induced behavioral sensitization.