GATOR2 complex-mediated amino acid signaling regulates brain myelination.

Amino acids are essential for cell growth and metabolism. Amino acid and growth factor signaling pathways coordinately regulate the mechanistic target of rapamycin complex 1 (mTORC1) kinase in cell growth and organ development. While major components of amino acid signaling mechanisms have been identified, their biological functions in organ development are unclear. We aimed to understand the functions of the critically positioned amino acid signaling complex GAP activity towards Rags 2 (GATOR2) in brain development. GATOR2 mediates amino acid signaling to mTORC1 by directly linking the amino acid sensors for arginine and leucine to downstream signaling complexes. Now, we report a role of GATOR2 in oligodendrocyte myelination in postnatal brain development. We show that the disruption of GATOR2 complex by genetic deletion of meiosis regulator for oocyte development (Mios, encoding a component of GATOR2) selectively impairs the formation of myelinating oligodendrocytes, thus brain myelination, without apparent effects on the formation of neurons and astrocytes. The loss of Mios impairs cell cycle progression of oligodendrocyte precursor cells, leading to their reduced proliferation and differentiation. Mios deletion manifests a cell type-dependent effect on mTORC1 in the brain, with oligodendroglial mTORC1 selectively affected. However, the role of Mios/GATOR2 in oligodendrocyte formation and myelination involves mTORC1-independent function. This study suggests that GATOR2 coordinates amino acid and growth factor signaling to regulate oligodendrocyte myelination.

GABAA receptors in the basal forebrain mediates emergence from propofol anaesthesia in rats.

PURPOSE: The aim of the current study was to explore the role of the basal forebrain (BF) in propofol anaesthesia. METHODS: In the present study, we observed the neural activities of the BF during propofol anaesthesia using calcium fibre photometry recording. Subsequently, ibotenic acid was injected into the BF to verify the role of the BF in propofol anaesthesia. Finally, to test whether GABAA receptors in the BF were involved in modulating propofol anaesthesia, muscimol (GABAA receptor agonist) and gabazine (GABAA receptor antagonist) were microinjected into the BF. Cortical electroencephalogram (EEG), time to loss of righting reflex (LORR), and recovery of righting reflex (RORR) under propofol anaesthesia were recorded and analysed. RESULTS: The activity of BF neurons was inhibited during induction of propofol anaesthesia and activated during emergence from propofol anaesthesia. In addition, non-specifical lesion of BF neurons significantly prolonged the time to RORR and increased delta power in the frontal cortex under propofol anaesthesia. Next, microinjection of muscimol into the BF delayed emergence from propofol anaesthesia, increased delta power of the frontal cortex, and decreased gamma power under propofol anaesthesia. Conversely, infusion of gabazine accelerated emergence times and decreased EEG delta power. CONCLUSIONS: The basal forebrain is involved in modulating frontal cortex delta activity and emergence from propofol anaesthesia. Additionally, the GABAA receptors in the basal forebrain are involved in regulating emergence propofol anaesthesia.

Gastrodin promotes CNS myelination via a lncRNA Gm7237/miR-142a/MRF pathway.

Treatment of central nervous system (CNS) demyelination is greatly hindered by lack of the knowledge regarding to underlying molecular mechanisms as well as therapeutic agents. Here, we report a novel small molecule agent, gastrodin (GAS), which can significantly promote CNS myelination in in vivo mice models. By using high-throughput sequencing analysis, we discover a key long non-coding RNA Gm7237 that can enhance CNS myelination and is up-regulated by GAS. Through using bioinformatic analysis and experimental validations, we further unravel that microRNA-142a (miR-142a) and its target myelin gene regulatory factor (MRF) is under the direct regulation by Gm7237. Finally, we demonstrate that Gm7237/miR-142a/MRF axis is the key pathway involved in CNS myelination mediated by GAS. Overall, our results provide not only a novel agent for therapeutic treatment of CNS demyelination but also a molecular basis responsible for GAS-promoted CNS myelination.

Metformin induces ferroptosis by targeting miR-324-3p/GPX4 axis in breast cancer.

Metformin is a widely prescribed hypoglycemic drug. Many studies have shown its anti-cancer properties. In the present study, we aimed to explore the effect of metformin on breast cancer and clarify the underlying mechanism. Our results showed that metformin induced ferroptosis in MDA-MB-231 cells through upregulating miR-324-3p expression. Overexpression of miR-324-3p inhibited cancer cell viability. miR-324-3p inhibitor promoted cell viability. Further studies showed that the effect of miR-324-3p was mediated by directly targeting glutathione peroxidase 4 (GPX4). miR-324-3p bound to the 3'-UTR of GPX4 and led to the downregulation of GPX4. In vivo studies showed that metformin induced ferroptosis by upregulating miR-324-3p in the xenograft model of breast cancer in mice. Our study suggested that metformin promotes ferroptosis of breast cancer by targeting the miR-324-3p/GPX4 axis. Metformin could act as a potential anti-cancer agent through the induction of ferroptosis.

miR-34c inhibits proliferation of glioma by targeting PTP1B.

Glioma is one of the most pervasive and invasive primary malignancies in the central nervous system. Due to its abnormal proliferation, glioma remains hard to cure at present. Protein tyrosine phosphatase 1B (PTP1B) has been proved to be involved in the process of proliferation in many malignancies. However, whether PTP1B is involved in the proliferation of glioma and how it acts are still unclear. In this study, the PTP1B expressions in glioma tissues and cells were determined by quantitative real-time PCR and western blot analysis. The effects of PTP1B on the proliferation characteristics of glioma were explored using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation assay, and tumor xenografts in mice. We found that the protein and mRNA levels of PTP1B in glioma tissues were significantly higher than those in paired nontumor tissues. MTT and clone formation assays showed that PTP1B is closely related to human glioma cell proliferation. In addition, TargetScan revealed that miR-34c regulates PTP1B. Mechanistically, we proved that miR-34c negatively regulates PTP1B and then participates in the regulation of glioma cell proliferation in vivo. Collectively, these results suggested that miR-34c inhibits the proliferation of human glioma cells by targeting PTP1B, which will provide a potential target for the treatment of glioma.

Activation of noradrenergic terminals in the reticular thalamus delays arousal from propofol anesthesia in mice.

Electroencephalogram monitoring during propofol (PRO) anesthesia typically features low-frequency oscillations, which may be involved with thalamic reticular nucleus (TRN) modulation. TRN receives noradrenergic inputs from the locus coeruleus (LC). We hypothesized that specific noradrenergic connections in the TRN may contribute to the emergence from PRO anesthesia. Intranuclei norepinephrine (NE) injections (n = 10) and designer receptors exclusively activated by designer drugs (DREADDs) (n = 10) were used to investigate the role of noradrenergic inputs from the LC to the TRN during PRO anesthesia. Whole-cell recording in acute brain slice preparations was used to identify the type of adrenoceptor that regulates noradrenergic innervation in the TRN. An intracerebral injection of NE into the TRN delays arousal in mice recovering from PRO anesthesia (means ± sd; 486.6 ± 57.32 s for the NE injection group vs. 422.4 ± 48.19 s for the control group; P = 0.0143) and increases the cortical-δ (0.1-4 Hz, 25.4 ± 2.9 for the NE injection group vs. 21.0 ± 1.7 for the control group; P = 0.0094) oscillation. An intra-TRN injection of NE also decreased the EC50 of PRO-induced unconsciousness (57.05 ± 1.78 mg/kg for the NE injection group vs. 72.44 ± 3.23 mg/kg for the control group; P = 0.0096). Moreover, the activation of LC-noradrenergic nerve terminals in the TRN using DREADDs increased the recovery time [466.1 ± 44.57 s for the clozapine N-oxide (CNO) injection group vs. 426.1 ± 38.75 s for the control group; P = 0.0033], decreased the EC50 of PRO-induced unconsciousness (64.77 ± 3.40 mg/kg for the CNO injection group vs. 74.00 ± 2.08 mg/kg for the control group; P = 0.0081), and increased the cortical-δ oscillation during PRO anesthesia (23.29 ± 2.58 for the CNO injection group vs. 19.56 ± 1.9 for the control group; P = 0.0213). In addition, whole-cell recording revealed that NE augmented the inhibitory postsynaptic currents in the TRN neurons via the α1-adrenoceptor. Our data indicated that enhanced NE signaling at the noradrenergic terminals of the LC-TRN projection delays arousal from general anesthesia, which is likely mediated by the α1-adrenoceptor activation. Our findings open a door for further understanding of the functions of various LC targets in both anesthesia and arousal.-Zhang, Y., Fu, B., Liu, C., Yu, S., Luo, T., Zhang, L., Zhou, W., Yu, T. Activation of noradrenergic terminals in the reticular thalamus delays arousal from propofol anesthesia in mice.

Activation of the P2X7 receptor in midbrain periaqueductal gray participates in the analgesic effect of tramadol in bone cancer pain rats.

Background Cancer pain is a well-known serious complication in metastatic or terminal cancer patients. Current pain management remains unsatisfactory. The activation of spinal and supraspinal P2X7 receptors plays a crucial role in the induction and maintenance mechanisms of various kinds of acute or chronic pain. The midbrain periaqueductal gray is a vital supraspinal site of the endogenous descending pain-modulating system. Tramadol is a synthetic, centrally acting analgesic agent that exhibits considerable efficacy in clinically relieving pain. The purpose of this study was to determine whether the activation of P2X7 receptor in the ventrolateral region of the periaqueductal gray (vlPAG) participates in the analgesic mechanisms of tramadol on bone cancer pain in rats. The bone cancer pain rat model was established by intratibial cell inoculation of SHZ-88 mammary gland carcinoma cells. The analgesic effects of different doses of tramadol (10, 20, and 40 mg/kg) were assessed by measuring the mechanical withdrawal threshold and thermal withdrawal latency values in rats by using an electronic von Frey anesthesiometer and radiant heat stimulation, respectively. Alterations in the number of P2X7 receptor-positive cells and P2X7 protein levels in vlPAG were separately detected by using immunohistochemistry and Western blot assay. The effect of intra-vlPAG injection of A-740003 (100 nmol), a selective competitive P2X7 receptor antagonist, on the analgesic effect of tramadol was also observed. Results The expression of P2X7 receptor in the vlPAG on bone cancer pain rats was mildly elevated, and the tramadol (10, 20, and 40 mg/kg) dose dependently relieved pain-related behaviors in bone cancer pain rats and further upregulated the expression of P2X7 receptor in the vlPAG. The intra-vlPAG injection of A-740003 pretreatment partly but significantly antagonized the analgesic effect of tramadol on bone cancer pain rats. Conclusions The injection of tramadol can dose dependently elicit analgesic effect on bone cancer pain rats by promoting the expression of the P2X7 receptor in vlPAG.

Three new 1-(p-hydroxybenzyl)phenanthrenes from Bletilla striata.

Three new benzylphenanthrenes, named 1-(p-hydroxybenzyl)-4,7-dimethoxyphenanthrene-2-ol (1), 1-(p-hydroxybenzyl)-4,7-dimethoxyphenanthrene-2,8-diol (2), and 1-(p-hydroxybenzyl)-4,7-dimethoxyphenanthrene-2,6-diol (3), along with a known analog were isolated from tubers of Bletilla striata. The structures of these new compounds were established by means of HR-ESI-MS, 1D, and 2D NMR.

[Effect of Corydalis Rhizoma and L-tetrahydropalmatine on dopamine system of hippocampus and striatum in morphine-induced conditioned place preference rats].

To investigate the effects of Corydalis Rhizoma and L-tetrahydropalma-tine (L-THP) on the levels of dopamine neurotransmitter (DA), dopamine transporter (DAT) and the second dopamine receptor (D2R) in learning and memory-related brain areas, hippocampus and striatum, the DA, DAT and D2R were detected in conditioned place preference (CPP) rats suffered from morphine. And comparation the degree of similarity and consistency of the pharmacological effects was also studied. The rats were trained in black compartments and white ones (drug-paired compartment) with the increasing doses of morphine for 10 days (hypodermically injected from 10 mg•kg⁻¹ to 100 mg•kg⁻¹). Models of CPP were validated in those psychological dependence rats after 48 h training. The dopamine contents were detected as soon as the materials of hippocampus and striatum are harvested from rats of NS control group and model group. The DAT and D2R levels are measured by Western blot. The high, medium and low dose group of Corydalis Rhizoma are given Corydalis Rhizoma 2, 1, 0.5 g•kg⁻¹ water extraction liquid respectively (which contains L-THP were 0.274, 0.137 and 0.137 mg respectively), and the high, medium and low dose group of L-THP were given L-THP 3.76, 1.88, 0.94 mg•kg⁻¹ lavage treatment respectively, NS treatment group were lavaged normal saline for 6 days and they were killed after test of CPP, again tested DA levels and expression of DAT and D2R similar to the front of materials. The reduction effects of CPP were observed in the groups of both Corydalis Rhizoma (2, 1 g•kg⁻¹) and L-THP (3.76, 1.88 mg•kg⁻¹) subjected to medicine for 6 days (P<0.01). Compared with the NS treatment group and the model group, the higher values including in the contents of neurotransmitter dopamine were detected of hippocampus and striatum (P<0.01, P<0.05), the DAT and D2R protein expression of Corydalis Rhizoma (2, 1 g•kg⁻¹) and L-THP (3.76, 1.88 mg•kg⁻¹) increased in hippocampus and striatum (P<0.01). Learning and memory-related brain regions hippocampus and striatum was another neuroanatomical sites of action in the treatment of mental dependence of fumarate and L-THP, its mechanism was related to lowering its elevated DA neurotransmitter levels, and increasing the expression of DAT and D2R. Corydalis Rhizoma could be play 14-times roles in effect of L-THP. The similar effects were observed on the neurotransmitter dopamine, DAT and D2R in learning and memory-related brain areas, hippocampus and striatum of the morphine- dependent rats.

Oligodendrocyte precursor cell-intrinsic effect of Rheb1 controls differentiation and mediates mTORC1-dependent myelination in brain.

Rheb1 is an immediate early gene that functions to activate mammalian target of rapamycin (mTor) selectively in complex 1 (mTORC1). We have demonstrated previously that Rheb1 is essential for myelination in the CNS using a Nestin-Cre driver line that deletes Rheb1 in all neural cell lineages, and recent studies using oligodendrocyte-specific CNP-Cre have suggested a preferential role for mTORC1 is myelination in the spinal cord. Here, we examine the role of Rheb1/mTORC1 in mouse oligodendrocyte lineage using separate Cre drivers for oligodendrocyte progenitor cells (OPCs) including Olig1-Cre and Olig2-Cre as well as differentiated and mature oligodendrocytes including CNP-Cre and Tmem10-Cre. Deletion of Rheb1 in OPCs impairs their differentiation to mature oligodendrocytes. This is accompanied by reduced OPC cell-cycle exit suggesting a requirement for Rheb1 in OPC differentiation. The effect of Rheb1 on OPC differentiation is mediated by mTor since Olig1-Cre deletion of mTor phenocopies Olig1-Cre Rheb1 deletion. Deletion of Rheb1 in mature oligodendrocytes, in contrast, does not disrupt developmental myelination or myelin maintenance. Loss of Rheb1 in OPCs or neural progenitors does not affect astrocyte formation in gray and white matter, as indicated by the pan-astrocyte marker Aldh1L1. We conclude that OPC-intrinsic mTORC1 activity mediated by Rheb1 is critical for differentiation of OPCs to mature oligodendrocytes, but that mature oligodendrocytes do not require Rheb1 to make myelin or maintain it in the adult brain. These studies reveal mechanisms that may be relevant for both developmental myelination and impaired remyelination in myelin disease.

[Effect of Corydalis yanhusuo and L-THP on Gastrointestinal Dopamine System in Morphine-Dependent Rats].

OBJECTIVE: To investigate the protective mechanism of Corydalis yanhuso and L-THP in morphine-dependent gastrointestinal injury rats. METHODS: 180 male rats were randomly divided into nine groups, 20 rats for each group: saline group (N), model group (M), NS treatment group and three different dosage of Corydalis yanhusuo and L-THP groups (low dose group,middle dose group and high dose group). The rat CPP (conditioned place preference) model was established by injecting the rats with an increasing dosage of morphine, all groups received CPP training in a black compartments and white ones (drug-paired compartment) for ten days. At 48 h after the final training, the performance of CPP models were assessed to make sure all models were exported correctly. Then the treatment groups were administered with different concentration of Corydalis yanhuso (0.5, 1 and 2 g/kg) and L-THP (0.94, 1.88 and 3.76 mg/kg) for six days. All rats were immediately killed after finish the last CPP test. For each group, ten rats were killed to detect the contents of DA in the stomach and duodenum through the fluorescence spectrophotometer. The expression levels of D2 receptor( D2R) in different tissues (gastric cardia, gastric body, pylorus and duodenum) were checked by Western-blot in the other rats. RESULTS: In the NS treatment group, the time when rats stay in the white ones were significantly decreased compared with the Corydalis yanhusuo treated groups (1 and 2 g/kg) and L-THP treated groups (1.88 and 3.76 mg/kg) (P < 0.01), the high expression of DA contents in the stomach and duodenum were significantly decreased (P < 0.01). However the protein level of D2R were notably lower in gastric cardia, gastric body, pylorus and duodenum (P < 0.01). CONCLUSION: Injuries of the gastrointestinal tract followed lower DA contents and an abnormal increase of D2R in the stomach and duodenum of rats, which induced by morphine-dependent could be reversed by treatment with Corydalis yanhusuo and L-THP. This is one of mechanism underlying the protective effects of gastrointestinal tract in morphine-dependent rats.

[Study on effects of Corydalis yanhusuo and L-THP on dopamine of reward circuitry in conditioned place preference rats and comparison].

OBJECTIVE: To study and compare the effect of Corydalis yanhusuo and L-THP on dopamine neurotransmitter and D2 receptor of reward circuitry in various cerebral areas of conditioned place preference model rats and the comparison of their effects. METHOD: The CPP model was established by injecting morphine in rats with increasing doses for 10 days. The initial dose of 10 mg x kg(-1), and the final dose of 100 mg x kg(-1), with 10 mg x kg(-1) increased each day. At 48 h after the final training, CPP was adopted to detect the successful establishment of the model. On the same day (12 d), they were orally administered with 2, 1, 0.5 g x kg(-1) C. yanhusuo (containing 0.153, 0.077 and 0.038 mg L-THP) and L-THP (3.76, 1.88, 0.94 mg x kg(-1)) for six days. On 18 d, CPP test was performed again. Next day, HPLC was adopted to determine the content of dopamine neurotransmitters of reward circuitry in VTA-NAc-PFC; Immunohistochemistry and Western blotting were adopted to detect the expression of D2 receptors. RESULT: Compared with the physiological saline treatment group, C. yanhusuo (2, 1 g x kg(-1)) and L-THP (3.76, 1.88 mg x kg(-1)) groups showed that rats stayed in a notably shorter period in white boxes (morphine-accompanied boxes) (P < 0.01 or P < 0.05), and revealed a remarkably lower dopamine content in VTA, NAc and PFC and the significant increase in the expression of D2 receptor (P < 0.01 or P < 0.05). CONCLUSION: The down-regulation of the increased dopamine content in reward nervous circuitry and the up-regulation of the expression of D2 receptor may be one of mechanisms of C. yanhusuo and L-THP in accelerating the recession of morphine's CPP effect Regarding the inhibition of morphine's CPP effect and the effect on dopamine system, the effect of C. yanhusuo traditional Chinese medicine containing one-fold L-THP monomer is equal to that of the independent application of around 24-fold L-THP monomer.

miR­30c reduces myocardial ischemia/reperfusion injury by targeting SOX9 and suppressing pyroptosis.

MicroRNAs (miRNAs or miRs) are commonly involved in regulating myocardial ischemia/reperfusion (I/R) injury by binding and silencing their target genes. However, whether miRNAs regulate myocardial I/R-induced pyroptosis remains unclear. The present study established an in vivo rat model of myocardial I/R injury and in vitro hypoxia/reoxygenation (H/R) injury model in rat primary cardiomyocytes to investigate the function and the underlying mechanisms of miRNAs on I/R injury-induced pyroptosis. RNA sequencing was utilized to select the candidate miRNAs between normal and I/R group. Reverse transcription-quantitative PCR and western blotting were performed to detect candidate miRNAs (miR-30c-5p, also known as miR-30c) and SRY-related high mobility group-box gene 9 (SOX9) expression, as well as expression of pyroptosis-associated proteins (NF-κB, ASC, caspase-1, NLRP3) in the myocardial I/R model. ELISA was used to measure pyroptosis-associated inflammatory markers IL-18 and IL-1ß. Moreover, the link between miR-30c and SOX9 was predicted using bioinformatics and luciferase reporter assay. In myocardial I/R injured rats, miR-30c was downregulated, while the expression of SOX9 was upregulated. Overexpression of miR-30c inhibited pyroptosis both in vivo and in vitro. Furthermore, miR-30c negatively regulated SOX9 expression by binding its 3'untranslated region. In conclusion, the miR-30c/SOX9 axis decreased myocardial I/R injury by suppressing pyroptosis, which may be a potential therapeutic target.

Claustrum modulates behavioral sensitivity and EEG activity of propofol anesthesia.

AIMS: The claustrum has long been regarded as a vital center for conscious control. Electrical stimulation or damage to the claustrum can result in decreased awareness or loss of consciousness, suggesting that the claustrum may be a target for the action of general anesthetics. This study aimed to determine the role of the claustrum in propofol anesthesia. METHODS: We first applied a fiber photometry calcium signal recording system to record the claustral neuronal activity during the entire process of propofol anesthesia. Chemogenetic activation of claustral neurones was then performed to verify their role in anesthesia. Finally, muscimol (GABAa receptor agonist) and gabazine (GABAa receptor antagonist) were microinjected into the claustrum to determine whether their GABAa receptors were involved in modulating propofol anesthesia. EEG and behavioral indicators, such as anesthetic sensitivity and efficacy, were recorded and analyzed. RESULTS: An evident anesthesia-related change in claustrum neuronal activity was suppressed during propofol-induced unconsciousness and restored following recovery from anesthesia. Chemogenetic activation of claustrum neurons results in attenuated propofol sensitivity, a shorter anesthesia duration, and an EEG shift toward wakefulness. Manipulation of GABAa receptors in the claustrum showed bidirectional control of propofol sensitivity, as activation decreases anesthesia efficiency while inactivation augments it. Additionally, inhibiting claustrum GABAa receptors increases cortical EEG slow waves. CONCLUSIONS: Claustrum neurones and their GABAa receptors are implicated in the modulation of propofol anesthesia in both behavioral and EEG assessments. Our findings create scope to reveal the brain targets of anesthetic action further and add to the existing evidence on the consciousness-modulating role of the claustrum.

PRG-1 prevents neonatal stimuli-induced persistent hyperalgesia and memory dysfunction via NSF/Glu/GluR2 signaling.

Neonatal repetitive noxious stimuli (RNS) has been shown to cause long-term harmful effects on nociceptive processing, learning, and memory which persist until adulthood. Plasticity-related gene 1 (PRG-1) regulates synaptic plasticity and functional reorganization in the brain during neuronal development. In this study, neonatal RNS rats were established by repetitive needle pricks to neonatal rats on all four feet to model repetitive pain exposure in infants. Neonatal RNS caused thermal hyperalgesia, mechanical allodynia, learning, and memory impairments which manifested in young rats and persisted until adulthood. Hippocampal PRG-1/N-ethylmaleimide sensitive fusion protein (NSF) interaction was determined to be responsible for the RNS-induced impairment via enhanced extracellular glutamate release and AMPAR GluR2 trafficking deficiency in a cell-autonomous manner. These pathways likely act synergistically to cause changes in dendritic spine density. Our findings suggest that PRG-1 prevents the RNS-induced hyperalgesia, learning, and memory impairment by regulating synaptic plasticity via NSF/Glu/GluR2 signaling.

Exosomal miR-487a derived from m2 macrophage promotes the progression of gastric cancer.

Tumor-associated macrophages contribute to cell growth, development, and metastasis in various cancers. However, the underlying mechanisms of M2 macrophage that modulate the progression of gastric cancer (GC) remain largely unknown. In this study, we detected the ratio of macrophages in GC tissues and found that the proportion of M2 macrophages was increased in GC tissues. We then co-cultured GC cells with M1 and M2 macrophages, respectively, and then assessed cell proliferation and tumorigenicity of GC cells by MTT and colony formation assay. The results indicated that M2 macrophages promoted the proliferation of GC cells, but M1 not. Besides, GW4869, an exosomes inhibitor, reduced the effects induced by M2 macrophage. Then, we isolated and identified exosomes derived from M1 and M2 macrophage, and confirmed that the exosomes could be taken up by GC cells. We demonstrated that M2 macrophage-exosomes could induce the proliferation and tumorigenesis in vitro and in vivo. Moreover, miR-487a was enriched in M2 macrophage-exosomes and further determined that miR-487a exert the functions by targeting TIA1. In conclusion, exosomal miR-487a derived from M2 macrophage promotes the proliferation and tumorigenesis in gastric cancer, and the novel findings might be helpful to the development of novel diagnostic and therapeutic methods in GC.

Effect of basal forebrain somatostatin and parvalbumin neurons in propofol and isoflurane anesthesia.

AIMS: The basal forebrain (BF) plays an essential role in wakefulness and cognition. Two subtypes of BF gamma-aminobutyric acid (GABA) neurons, including somatostatin-expressing (GABASOM ) and parvalbumin-positive (GABAParv ) neurons, function differently in mediating the natural sleep-wake cycle. Since the loss of consciousness induced by general anesthesia and the natural sleep-wake cycle probably share similar mechanisms, it is important to clarify the accurate roles of these neurons in general anesthesia procedure. METHODS: Based on two transgenic mouse lines expressing SOM-IRES-Cre and PV-IRES-Cre, we used a combination of genetic activation, inactivation, and chronic ablation approaches to further explore the behavioral and electroencephalography (EEG) roles of BFSOM and BFParv neurons in general anesthesia. After a single intravenous injection of propofol and the induction and recovery times of isoflurane anesthesia, the anesthesia time was compared. The changes in cortical EEG under different conditions were also compared. RESULTS: Activation of BF GABASOM neurons facilitates both the propofol and isoflurane anesthesia, manifesting as a longer anesthesia duration time with propofol anesthesia and a fast induction time and longer recovery time with isoflurane anesthesia. Moreover, BF GABASOM -activated mice displayed a greater suppression of cortical electrical activity during anesthesia, showing an increase in δ power bands or a simultaneous decrease in high-frequency power bands. However, only a limited and nuanced effect on propofol and isoflurane anesthesia was observed with the manipulated BF GABAParv neurons. CONCLUSIONS: Our results suggested that BF GABASOM neurons play a critical role in propofol and isoflurane general anesthesia, while BF GABAParv neurons appeared to have little effect.

Diazoxide Protects against Myocardial Ischemia/Reperfusion Injury by Moderating ERS via Regulation of the miR-10a/IRE1 Pathway.

Nowadays, reperfusion is still the most effective treatment for ischemic heart disease. However, cardiac reperfusion therapy would lead to reperfusion injury, which may have resulted from endoplasmic reticulum stress (ERS) during reperfusion. Diazoxide (DZ) is a highly selective mitochondrial adenosine triphosphate-sensitive potassium channel opener. Its protective effect on I/R injury has been confirmed in many organs such as the heart and brain. However, the mechanism of its protective effect has not been fully elucidated. MicroRNAs (miRNAs) are widely involved in pathologies of heart disease. In this study, we found that miR-10a expression was highly upregulated in the myocardial I/R groups, and DZ treatment significantly reduced the expression of miR-10a. More importantly, we found that DZ treatment can moderate ERS via regulation of the miR-10a/IRE1 pathway in the I/R and H/R models, thereby protecting myocardial H/R injury.

Effects of Propofol on Electrical Synaptic Strength in Coupling Reticular Thalamic GABAergic Parvalbumin-Expressing Neurons.

Electrical synapses between neurons exhibit a high degree of plasticity, which makes critical contributions to neuronal communication. The GABAergic parvalbumin-expressing (PV+) neurons in the thalamic reticular nucleus (TRN) interact with each other through electrical and chemical synapses. Plasticity of electrical synaptic transmission in TRN plays a key role in regulating thalamocortical and corticothalamic circuits and even the formation of consciousness. We here examined the effects of propofol, a commonly used general anesthetic agent, on the strength of electrical synapses between TRN PV+ neurons by fluorescence-guided patch-clamp recording and pharmacological methods. Results show that 100 µM propofol reduced the electrical synaptic strength between TRN PV+ neurons. Notably, the propofol-induced depression of electrical synaptic strength between TRN PV+ neurons was diminished by saclofen (10 µM, antagonist of GABAB receptors), but not blocked by gabazine (10 µM, antagonist of GABAA receptors). Application of baclofen (10 µM, agonist of GABAB receptors), similar to propofol, also reduced the electrical synaptic strength between TRN PV+ neurons. Moreover, the propofol-induced depression of electrical synaptic strength between TRN PV+ neurons was abolished by 9-CPA (100 µM, specific adenylyl cyclase inhibitor), and by KT5720 (1 µM, selective inhibitor of PKA). Our findings indicate that propofol acts on metabotropic GABAB receptors, resulting in a depression of electrical synaptic transmission of coupled TRN PV+ neurons, which is mediated by the adenylyl cyclase-cAMP-PKA signaling pathway. Our findings also imply that propofol may change the thalamocortical communication via inducing depression of electrical synaptic strength in the TRN.

Basal Forebrain Cholinergic Activity Modulates Isoflurane and Propofol Anesthesia.

Cholinergic neurons in the basal forebrain (BF) have long been considered to be the key neurons in the regulation of cortical and behavioral arousal, and cholinergic activation in the downstream region of the BF can arouse anesthetized rats. However, whether the activation of BF cholinergic neurons can induce behavior and electroencephalogram (EEG) recovery from anesthesia is unclear. In this study, based on a transgenic mouse line expressing ChAT-IRES-Cre, we applied a fiber photometry system combined with GCaMPs expression in the BF and found that both isoflurane and propofol inhibit the activity of BF cholinergic neurons, which is closely related to the consciousness transition. We further revealed that genetic lesion of BF cholinergic neurons was associated with a markedly increased potency of anesthetics, while designer receptor exclusively activated by designer drugs (DREADD)-activated BF cholinergic neurons was responsible for slower induction and faster recovery of anesthesia. We also documented a significant increase in δ power bands (1-4 Hz) and a decrease in ß (12-25 Hz) power bands in BF cholinergic lesioned mice, while there was a clearly noticeable decline in EEG δ power of activated BF cholinergic neurons. Moreover, sensitivity to anesthetics was reduced after optical stimulation of BF cholinergic cells, yet it failed to restore wake-like behavior in constantly anesthetized mice. Our results indicate a functional role of BF cholinergic neurons in the regulation of general anesthesia. Inhibition of BF cholinergic neurons mediates the formation of unconsciousness induced by general anesthetics, and their activation promotes recovery from the anesthesia state.