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.

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.

Correction to: Longitudinal transcriptomic characterization of viral genes in HSV-1 infected tree shrew trigeminal ganglia.

An amendment to this paper has been published and can be accessed via the original article.

Methamphetamine leads to the alterations of microRNA profiles in the nucleus accumbens of rats.

CONTEXT: MicroRNA (miRNA) is an important regulator of gene expression. Methamphetamine (METH) induces a variety of alterations in different systems by affecting gene expression, but the effects of METH on miRNA profiles need to be elucidated. OBJECTIVES: This study develops a rat model of METH addiction, and analyzes the expression profile alterations of miRNA in nucleus accumbens (NAc) of the METH-addicted rats. MATERIALS AND METHODS: Sprague-Dawley rats were administered 10 mg/kg METH or vehicle twice a day for 4 weeks. The addictive behaviour of rats was estimated by CPP test. The pathological changes of brain tissues were then observed by HE and Glee silver staining. The miRNA profile analysis of the NAc of the rats was performed using an Illumina HiSeq™ 2500 sequencing system. RESULTS: CPP test indicated that METH significantly prolonged the residence time of the rats in the drug box (from 307 ± 97 to 592 ± 96 s). The pathological staining showed the distorted axons, and fewer polarized neurons in the METH-treated rats. We further identified 40 differential miRNAs (17 up- and 23 down-regulated) and three novel miRNAs (novel 237, 296 and 501) that responded to METH. The bioinformatic analysis for the potential targets of the differential miRNA suggests that the downstream were concentrated in the Wnt signalling pathway, tuberculosis, toxoplasmosis, spliceosome, lysosome, and axon guidance. DISCUSSION AND CONCLUSIONS: A number of miRNAs responding to METH were identified in the NAc of rats. These METH-regulated miRNAs provide a new perspective for revealing the molecular mechanisms of METH addiction.

LncRNA HOTAIR promotes renal interstitial fibrosis by regulating Notch1 pathway via the modulation of miR-124.

AIM: To understand the mechanism of long non-coding RNA (LncRNA) HOTAIR on renal interstitial fibrosis (RIF) by regulating Notch1 pathway via the modulation of miR-124. METHODS: Unilateral ureteral occlusion (UUO) was used to construct the RIF rat model. HK-2 cells induced by TGF-ß1 were used for the in vitro experiment, which were divided into five groups: Vehicle, TGF-ß1, si-HOTAIR+TGF-ß1, miR-124 inhibitor+TGF-ß1, and si-HOTAIR+miR-124 inhibitor+TGF-ß1 groups. Quantitative real-time PCR (qRT-PCR) and Western blot were performed to detect the expression of HOTAIR, miR-124, Notch1- and epithelial-to-mesenchymal transition (EMT)-related proteins. RESULTS: Significant elevated HOTAIR and reduced miR-124 were presented in UUO rats and TGF-ß1-induced HK-2 cells in a time-dependent manner, with the increased Jagged1 (JAG1), Notch1, NICD, α-SMA and FN, as well as the decreased E-cadherin (all P < 0.05). Compared with the TGF-ß1 group, cells in the si-HOTAIR+TGF-ß1 group were remarkably declined in cell proliferation and the protein expressions of JAG1, Notch1, NICD, α-SMA, and FN, but dramatically higher in E-cadherin expression (all P < 0.05). However, in comparison with the si-HOTAIR+TGF-ß1 group, cells in the si-HOTAIR+miR-124 inhibitor+TGF-ß1 group were apparently improved in proliferation and the protein expression of JAG1, Notch1, NICD, α-SMA, and FN, but substantially reduced in the level of E-cadherin protein (all P < 0.05). CONCLUSION: Silencing lncRNA HOTAIR can up-regulate miR-124 to block Notch1 pathway, and thereby alleviating EMT and RIF, indicating HOTAIR as a potential target for RIF treatment.

Nrf2 expression, mitochondrial fission, and neuronal apoptosis in the prefrontal cortex of methamphetamine abusers and rats.

Methamphetamine (MA), a representative amphetamine-type stimulant, is one of the most abused drugs worldwide. Studies have shown that MA-induced neurotoxicity is strongly associated with oxidative stress and apoptosis. While nuclear factor E2-related factor 2 (Nrf2), an antioxidant transcription factor, is known to exert neuroprotective effects, its role in MA-induced dopaminergic neuronal apoptosis remains incompletely understood. In the present study, we explored the effects of MA on the expression levels of Nrf2, dynamin-related protein 1 (Drp1), mitofusin 1 (Mfn1), cytochrome c oxidase (Cyt-c), and cysteine aspartate-specific protease 3 (Caspase 3), as well as the correlations between Nrf2 and mitochondrial dynamics and apoptosis. Brain tissue from MA abusers was collected during autopsy procedures. An MA-dependent rat model was also established by intraperitoneal administration of MA (10 mg/kg daily) for 28 consecutive days, followed by conditioned place preference (CPP) testing. Based on immunohistochemical staining and western blot analysis, the protein expression levels of Nrf2 and Mfn1 showed a decreasing trend, while levels of Drp1, Cyt-c, and Caspase 3 showed an increasing trend in the cerebral prefrontal cortex of both MA abusers and MA-dependent rats. Notably, the expression of Nrf2 was positively associated with the expression of Mfn1, but negatively associated with the expression levels of Drp1, Cyt-c, and Caspase 3. These findings suggest that oxidative stress and mitochondrial fission contribute to neuronal apoptosis, with Nrf2 potentially playing a critical role in MA-induced neurotoxicity.

Inhibition of glycolysis prevents behavioural changes in mice with MK801-induced SCZ model by alleviating lactate accumulation and lactylation.

Schizophrenia (SCZ) is a debilitating neuropsychiatric disorder with a complex aetiology. Cognitive symptoms and hippocampal changes have been implicated in the pathophysiology of SCZ. Changes in metabolites level and up-regulated glycolysis have been reported in previous studies, which may be related to the hippocampal dysfunction in SCZ. However, the pathological mechanism of glycolysis involved in the pathogenesis of SCZ remains unclear. Therefore, the change of glycolysis level and the involvement in SCZ need to be further studied. In our study, MK801 was used to induce an SCZ mouse model and cell model in vivo and in vitro. Western blotting was performed to evaluate the levels of glycolysis, metabolites, and lactylation in hippocampal tissue of mice with SCZ or cell models. The level of high mobility group protein 1 (HMGB1) in the medium of MK801-treated primary hippocampal neurons was examined. Apoptosis was evaluated in HMGB1-treated hippocampal neurons by flow cytometry. The glycolysis inhibitor 2-DG prevented behavioural changes in the MK801-induced SCZ mouse model. The lactate accumulation and level of lactylation were alleviated in the hippocampal tissue of MK801-treated mice. Glycolysis was enhanced, and lactate accumulated in MK-801-treated primary hippocampal neurons. In addition, the level of HMGB1 increased in the medium and induced apoptosis in primary hippocampal neurons. Together, the data showed that glycolysis and lactylation increased in the MK801-induced SCZ model in vivo and in vitro, and this effect could be prevented by 2-DG (a glycolysis inhibitor). Glycolytic related HMGB1 upregulation may induce apoptosis in hippocampal neurons downstream.

The effects of ketamine and methamphetamine on neurotransmitters, glutamate receptors, and conditioned place preference in rat.

Combined methamphetamine (MA) and ketamine (KET) abuse is a serious issue. At present, however, few studies have explored the mechanism underlying their combined addiction. We established a rat conditioned place preference (CPP) model. We investigated the role of dopamine (DA), 5-hydroxytryptamine (5-HT), monoamine oxidase (MAO), glutamate receptor 1 (GluR1), and glutamate receptor 2 (GluR2) in combined MA and KET addiction. The expression levels of DA, 5-HT, and MAO were detected by enzyme-linked immunosorbent assay (ELISA), and the expressions levels of GluR1 and GluR2 were detected by western blotting. Our results showed that MA and KET successfully induced CPP in rats respectively, and KET enhanced MA-induced CPP effects, although not significantly, and KET can reduce the MA-induced increase in DA, 5-HT, MAO and promoted the MA-induced increase in GluR1 and GluR2. Therefore, it suggested that DA, 5-HT, MAO, GluR1, and GluR2 expression may be involved in the mechanism underlying MA and KET-induced drug addiction in rats. Moreover, When MA and KET are used in combination, KET appears to play a dual addictive and anti-addictive role in the regulation of MA addiction.

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.

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.

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.

Near infrared spectral calibration model transfer without standards by screening spectral points with scale invariant feature transform from master samples spectra.

In order to realize calibration model transfer of near infrared (NIR) spectra without standards, scale invariant feature transform (SIFT) algorithm was applied to extract characteristic spectral points of NIR spectra in this study. Three sets of spectral points were selected by SIFT from the spectra of precision detection (SPD) of a radix scutellariae sample by continuously testing the sample three times. Aiming at obtaining high consistency of the three sets, the orthogonal table L9 (34) was used to optimize the parameters of SIFT. Basing on the NIR spectra of several representative radix scutellariae samples, a series of spectral point sets were screened by SIFT with the optimized parameters. Three methods of further treating the spectral points sets to optimize the combination of the spectral points and provided three spectral point sets, which were recorded as Ui, Uu and Uur, respectively. The partial least square (PLS) calibration models for predicting baicalin content of radix scutellariae were built on whole wavelengths, Ui, Uu and Uur at different number of latent variables (nLVs), respectively. Compared with other PLS models, the models of SIFTur-PLS built on Uur, which was obtained by taking union of the firstly selected spectral point sets, then eliminating the points with high deviance of SPD and those with high correlativity from the union, are most robust and always give lower or lowest prediction errors for both master and slave samples at many nLVs. It is a good way to filter stable, highly independent and characteristic spectral points to build robust PLS calibration models by combining SIFT algorithm with standard deviance analysis of SPD and correlative analysis. The models can be directly shared by the slave instrument, without needing transfer sets, and without requiring to correct the spectra of slave instruments or spectral calibration models.

Ketamine Affects the Expression of ErbB4 in the Hippocampus and Prefrontal Cortex of Rats.

Schizophrenia is a severe chronic neuropsychiatric disorder, and its exact pathogenesis remains unclear. This study investigated the effect of ketamine on the expression of ErbB4 (considered a schizophrenia candidate gene) in the hippocampus and prefrontal cortex of rats. Rats were randomly divided into four groups: control, low-dose, medium-dose and high-dose groups. The low-dose, medium-dose and high-dose groups were intraperitoneally injected with 15 mg/kg, 30 mg/kg and 60 mg/kg ketamine, respectively, twice a day (9:00 a.m. and 9:00 p.m.); the control group was administered normal saline. The treatment lasted 7 days. After treatment, rats were euthanized, and their brain tissues were collected and then analyzed by immunohistochemistry. The results of immunohistochemistry staining demonstrated that the ErbB4 protein was expressed exclusively in the CA3 region of the hippocampus and the Cg1 region of the prefrontal cortex. Ketamine administration significantly decreased the expression of ErbB4 in a dose-dependent manner. The high-dose ketamine treatment was found to be optimal for establishing a rat model for schizophrenia. Ketamine induced symptoms similar to schizophrenia in humans. The ketamine-induced rat model for schizophrenia constructed in this study provides novel insights to better understand the pathogenic mechanisms of schizophrenia and aid in drug discovery.

The Potential Role of PKA/CREB Signaling Pathway Concerned with Gastrodin Administration on Methamphetamine-Induced Conditioned Place Preference Rats and SH-SY5Y Cell Line.

To investigate the effects of gastrodin (GAS) on methamphetamine (MA)-induced conditioned place preference (CPP) in rats and explore its potential mechanisms. MA (10 mg/kg) was initially injected intraperitoneally (i.p.) in rats, after which they were administered either MA or saline alternately from day 4 to 13 (D4-13) for 10 days, followed by treatment with GAS (10 or 20 mg/kg, i.p.) on D15-21 for 7 days. The rats underwent CPP testing after MA and GAS treatment. In vitro, SH-SY5Y cells were exposed to MA (2.0 mM) for 24 h, followed by treatment with GAS (2.0 or 4.0 mM) for 24 h. The expression levels of PKA, P-PKA, CREB, and P-CREB proteins in the prefrontal cortex, nucleus accumbens, and ventral tegmental area of MA-induced CPP rats and in SH-SY5Y cells were detected by Western blot analysis. The MA-induced CPP rat model was successfully established. The administration of MA stimulated a significant alteration in behavior, as measured by the CPP protocol. After treatment with GAS, the amount of time rats spent in the MA-paired chamber was significantly reduced. Results also showed that MA increased the expression levels of PKA, P-PKA, CREB, and p-CREB proteins in the prefrontal cortex, nucleus accumbens, and ventral tegmental area of CPP rats and in SH-SY5Y cells (p < 0.05). GAS attenuated the effect of MA-induced CPP in rats and decreased the expression levels of proteins in vivo and in vitro. Our study suggests that GAS can attenuate the effects of MA-induced CPP in rats by regulating the PKA/CREB signaling pathway.

LINK-A lncRNA activates HIF1α signaling and inhibits podocyte cell apoptosis in diabetic nephropathy.

Previous studies have revealed that long intergenic non-coding RNA for kinase activation (LINK-A), a long non-coding RNA (lncRNA) promotes disease progression in triple-negative breast cancer by activating hypoxia-inducible factor 1α (HIF1α). However, the activation of HIF1α has also been demonstrated to improve diabetic nephropathy. It is therefore reasonable to expect that LINK-A may also participate in diabetic nephropathy. In the current study, the expression of LINK-A lncRNA and HIF1α was determined in renal biopsies of patients with diabetic nephropathy. LINK-A lncRNA and HIF1α expression levels were detected by reverse transcription quantitative (RT-q) PCR and ELISA in diabetic patients without complications and used as controls. Correlations between LINK-A lncRNA and HIF1α expression were analyzed using Pearson's correlation coefficient. Effects of lncRNA and HIF1α overexpression on LINK-A lncRNA expression, HIF1α expression and cell apoptosis were assessed using RT-qPCR, western blotting and a cell apoptosis assay. The results revealed that LINK-A lncRNA and HIF1α were downregulated in patients with diabetic nephropathy, as well as in diabetic patients without complications. The lowest expression of LINK-A lncRNA and HIF1α were observed in healthy controls. A positive correlation was identified between LINK-A lncRNA and HIF1α in both patients groups, but not in the control group. LINK-A lncRNA and HIF1α overexpression inhibited the apoptosis of mouse podocyte cells under a high glucose treatment. LINK-A lncRNA overexpression also promoted HIF1α expression in mouse podocyte cells, while HIF1α overexpression did not significantly affect LINK-A lncRNA expression. In conclusion, LINK-A lncRNA may activate HIF1α signaling resulting in the improvement of diabetic nephropathy treatment.

Protective effect of gastrodin against methamphetamine-induced autophagy in human dopaminergic neuroblastoma SH-SY5Y cells via the AKT/mTOR signaling pathway.

Methamphetamine (METH) has been shown to induce neuropathological dysfunction and irreversible brain cell damage. Prior studies indicated the involvement of autophagy in METH-induced neurotoxicity. However, the underlying mechanism by which autophagy contributes to METH-induced neurotoxicity remains elusive. Gastrodin, a primary bioactive constituent of Gastrodia elata-an orchid used in traditional Chinese medicine-is used widely to treat stroke, dementia, and headache. This study investigates whether METH induces autophagy in the human dopaminergic neuroblastoma cell line SH-SY5Y, then examines the neuroprotective effects of gastrodin against autophagy in METH-treated SH-SY5Y cells. The effects of METH on the protein expressions of autophagy-related genes (LC3B and Beclin-1) were evaluated with and without gastrodin. The presence of autophagosomes in the METH-induced treatment with and without gastrodin is revealed through transmission electron microscopy. Pharmacological intervention was employed to study the role of the AKT/mTOR signaling pathway in the gastrodin-mediated neuroprotection against METH-induced autophagy. The present results indicate that METH exposure elevates the protein expression levels of LC3B and Beclin-1 in a dose- and time-dependent manner. Gastrodin is observed to block the METH-induced upregulation of LC3B and Beclin-1 protein expression significantly. Gastrodin is found to exhibit an anti-autophagic effect on the inhibition of the METH-induced Beclin-1 protein expression, partly via the AKT/mTOR These findings may aid the development of a gastrodin-based therapeutic strategy for treating METH-induced neurotoxicity.

Rare Death Via Histamine Poisoning Following Crab Consumption: A Case Report.

Histamine poisoning (scombroid food poisoning) is a toxicity syndrome that results from eating spoiled fish. To date, however, few poisoning (or mortality) cases have been reported in relation to crab consumption. Here, we describe a very uncommon case in which a 37-year-old woman and her 14-year-old son ate cooked crabs (Scylla serrata), resulting in the death of the female. Samples of vomitus, food residue, liver tissue, gastric content, intestinal content, and cardiac blood were analyzed by high-performance liquid chromatography. Toxicological analysis revealed that histamine concentrations were very high in the cooked crab (47.08 mg/100 g) and intestinal content (22.54 mg/100 g). Comparing our toxicological results, police investigations, and family member statements, it can be assumed that the decedent ingested spoiled crabs, and by excluding other causes of death, lethal intoxication with histamine poisoning was confirmed.