NMDAR (2C) deletion in astrocytes relieved LPS-induced neuroinflammation and depression.

The link between neuroinflammation and depression is a subject of growing interest in neuroscience and psychiatry; meanwhile, the precise mechanisms are still being unrevealed. However, glial cell activation, together with cytokine level elevation, suggests a connection between neuroinflammation and the development or exacerbation of depression. Glial cells (astrocytes) communicate with neurons via their extracellular neurotransmitter receptors, including glutamate receptors NMDARs. However, these receptor roles are controversial and enigmatic in neurological disorders, including depression. Therefore, we hypothesized whether NMDAR subnit NR2C deletion in the astrocytes exhibited anti-depressive effects concurrent with neuroinflammation prevention. To assess, we prepared astrocytic-NR2C knockout mice (G-2C: GFAPCre+Grin2Cflox/flox), followed by LPS administration, behavior tests, and biochemical analysis. Stimulatingly, astrocytic-NR2C knockout mice (G-2C) did not display depressive-like behaviors, neuroinflammation, and synaptic deficits upon LPS treatment. PI3K was impaired upon LPS administration in control mice (Grin2Cflox/flox); however, they were intact in the hippocampus of LPS-treated G-2C mice. Further, PI3K activation (via PTEN inhibition by BPV) restored neuroinflammation and depressive-like behavior, accompanied by altered synaptic protein and spine numbers in G-2C mice in the presence of LPS. In addition, NF-κB and JNK inhibitor (BAY, SP600125) treatments reversed the effects of BPV. Moreover, these results were further validated with an NR2C antagonist DQP-1105. Collectively, these observations support the astrocytic-NR2C contribution to LPS-induced neuroinflammation, depression, and synaptic deficits.

Hypothalamic CRF neurons facilitate brain reward function.

Aversive stimuli activate corticotropin-releasing factor (CRF)-expressing neurons in the paraventricular nucleus of hypothalamus (PVNCRF neurons) and other brain stress systems to facilitate avoidance behaviors. Appetitive stimuli also engage the brain stress systems, but their contributions to reward-related behaviors are less well understood. Here, we show that mice work vigorously to optically activate PVNCRF neurons in an operant chamber, indicating a reinforcing nature of these neurons. The reinforcing property of these neurons is not mediated by activation of the hypothalamic-pituitary-adrenal (HPA) axis. We found that PVNCRF neurons send direct projections to the ventral tegmental area (VTA), and selective activation of these projections induced robust self-stimulation behaviors, without activation of the HPA axis. Similar to the PVNCRF cell bodies, self-stimulation of PVNCRF-VTA projection was dramatically attenuated by systemic pretreatment of CRF receptor 1 or dopamine D1 receptor (D1R) antagonist and augmented by corticosterone synthesis inhibitor metyrapone, but not altered by dopamine D2 receptor (D2R) antagonist. Furthermore, we found that activation of PVNCRF-VTA projections increased c-Fos expression in the VTA dopamine neurons and rapidly triggered dopamine release in the nucleus accumbens (NAc), and microinfusion of D1R or D2R antagonist into the NAc decreased the self-stimulation of these projections. Together, our findings reveal an unappreciated role of PVNCRF neurons and their VTA projections in driving reward-related behaviors, independent of their core neuroendocrine functions. As activation of PVNCRF neurons is the final common path for many stress systems, our study suggests a novel mechanism underlying the positive reinforcing effect of stressful stimuli.

A novel dopamine D2 receptor-NR2B protein complex might contribute to morphine use disorders.

Dopamine receptors can form heteromeric interactions with other receptors, including glutamate receptors, and present a novel pharmacological target because it contribute to dopamine-dysregulated brain disorders such as addiction and other motor-related diseases. In addition, dopamine receptors D2 (D2Rs) and glutamate NMDA receptors subtype-NR2B have been implicated in morphine use disorders; however, the molecular mechanism underlying the heteromeric complex of these two receptors in morphine use disorders is unclear. Herein, we focus on interactions between D2R and NR2B in morphine-induced conditioned place preference (CPP) and hyperlocomotion mice models. We found that the D2R-NR2B complex significantly increases in morphine-induced mice models, accompanied by ERK signaling impairment, implying the complex could contribute to the morphine addiction pathophysiological process. Further, we design a brain-penetrant interfering peptide (TAT-D2-KT), which could disrupt interactions of D2R-NR2B and decrease addictive-like behaviors concurrent to ERK signaling improvement. In summary, our data provided the first evidence for a D2R-NMDAR complex formation in morphine use disorders and its underlying mechanism of ERK signaling, which could present a novel therapeutic target with direct implications for morphine acquisition and relapse treatment.

EPO prevents neuroinflammation and relieves depression via JAK/STAT signaling.

AIMS: Erythropoietin (EPO) is a glycoprotein cytokine that exerts therapeutic potential on neurological disorders by promoting neurogenesis and angiogenesis. However, its role as an antidepressant via anti-inflammatory axes is poorly explored. Furthermore, chronic inflammation can induce neuroinflammation, concurrent with depressive-like behaviors that anti-inflammatory and antidepressant agents could avert. Here, we aimed to elucidate the antidepressant potential of Erythropoietin (EPO) in the LPS-induced depression model. MAIN METHODS: For in vivo analysis, mice were treated with LPS (2 mg/kg BW), Erythropoietin (EPO) (5000 U/kg/day), (Ruxolitinib,15 mg/kg), and K252a (25 µg/kg). Depressive-like behaviors were confirmed via behavior tests, including OFT, FST, SPT, and TST. Cytokines were measured via ELISA, while IBA-1/GFAP expression was determined by immunofluorescence. Further, the desired gene expression was measured by immunoblotting. For in vitro analysis, BV2 and N2a cell lines were cultured, treated with LPS, EPO, Ruxolitinib, and K252a, collected, and analyzed. KEY FINDINGS: LPS treatment significantly induced neuroinflammation accompanied by depression-like behaviors in mice. However, EPO treatment rescued LPS-induced changes by averting cytokine production, secretion, and glial cell activation and reducing depressive-like behaviors in mice. Surprisingly, EPO treatment ameliorated LPS-induced JAK2/STAT5 signaling impairment, as validated by JAK2-antagonism. Furthermore, synaptic and dendritic spine defects and BNDF/TrkB signaling upon LPS administration could be prevented by EPO treatment. SIGNIFICANCE: EPO could act as an antidepressant via its anti-inflammatory potential by regulating JAK2/STAT5 signaling.

An Emerging Strategy for Muscle Evanescent Trauma Discrimination by Spectroscopy and Chemometrics.

Trauma is one of the most common conditions in the biomedical field. It is important to identify it quickly and accurately. However, when evanescent trauma occurs, it presents a great challenge to professionals. There are few reports on the establishment of a rapid and accurate trauma identification and prediction model. In this study, Fourier transform infrared spectroscopy (FTIR) and microscopic spectroscopy (micro-IR) combined with chemometrics were used to establish prediction models for the rapid identification of muscle trauma in humans and rats. The results of the average spectrum, principal component analysis (PCA) and loading maps showed that the differences between the rat muscle trauma group and the rat control group were mainly related to biological macromolecules, such as proteins, nucleic acids and carbohydrates. The differences between the human muscle trauma group and the human control group were mainly related to proteins, polysaccharides, phospholipids and phosphates. Then, a partial least squares discriminant analysis (PLS-DA) was used to evaluate the classification ability of the training and test datasets. The classification accuracies were 99.10% and 93.69%, respectively. Moreover, a trauma classification and recognition model of human muscle tissue was constructed, and a good classification effect was obtained. The classification accuracies were 99.52% and 91.95%. In conclusion, spectroscopy and stoichiometry have the advantages of being rapid, accurate and objective and of having high resolution and a strong recognition ability, and they are emerging strategies for the identification of evanescent trauma. In addition, the combination of spectroscopy and stoichiometry has great potential in the application of medicine and criminal law under practical conditions.

Optimize the combination regimen of Trastuzumab and Nab-paclitaxel in HER2-positive tumors via modulating Caveolin-1 expression by lovastatin.

The combination regimen of trastuzumab (Tras) plus Nab-paclitaxel (Nab) is recommended to treat HER2-positive (HER2+) cancers. However, they exert effects in different mechanisms: Tras need to stay on cell membranes, while Nab need to be endocytosed, therefore the concurrent combination regimen may not be the best one in HER2+ tumors treatment. Caveolin-1 (Cav-1) is a key player in mediating their endocytosis and is associated with their efficacy, but few researches noticed the opposite effect of Cav-1 expression on the combination efficacy. Herein, we systematically studied the Cav-1 expression level on the combination efficacy and proposed an optimized and clinically feasible combination regimen for HER2+ Cav-1High tumor treatment. In the regimen, lovastatin (Lova) was introduced to modulate the Cav-1 expression and the results indicated that Lova could downregulate Cav-1 expression, increase Tras retention on cell membrane and enhance the in vitro cytotoxicity of Tras in HER2+ Cav-1High cells but not in HER2+ Cav-1Low cells. Therefore, by exchanging the dosing sequence of Nab and Tras, and by adding Lova at appropriate time points, the precise three-drug-sequential regimen (PTDS, Nab(D1)-Lova(D2)-Lova & Tras(D2+12 h)) was established. Compared with the concurrent regimen, the PTDS regimen exhibited a higher in vitro cytotoxicity and a stronger tumor growth inhibition in HER2+ Cav-1High tumors, which might be a promising combination regimen for these patients in clinics.

LY235959 attenuates development phase of Methamphetamine-Induced behavioral sensitization through the PP2A/B - AKT cascade in the dorsal striatum of C57/BL6 mice.

Drug addiction can be described as a chronic and relapsing brain disease. Behavioral sensitization is common animal model in the study of addiction and N-Methyl-D-aspartate subtype of glutamate receptor (NMDAR) is believed play key role in this process. LY235959 is a competitive NMDAR antagonist, however, its effect on methamphetamine (METH)-induced behavioral sensitization is not been reported yet. In this study, we choose three doses (0.33 mg/kg, 1.0 mg/kg, and 3.0 mg/kg) of LY235959 to investigate its effect on locomotor activity, METH-induced behavioral sensitization and different phases of it in C57/BL6 mice. We also used western blotting to examine the PP2A/B - AKT cascade which had been proved involved in METH-induced behavioral sensitization in the dorsal striatum (DS). The results showed that only 0.33 mg/kg LY235959 increased locomotor activity dramatically, however, 1.0 mg/kg and 3.0 mg/kg of LY235959 could attenuate METH-induced behavioral sensitization markedly. We also found that LY235959 only disrupted the development phase of METH-induced behavioral sensitization and the following western blotting results further indicated that PP2A/B - AKT cascade might involve in this process. Taken together, these results indicated that LY235959 attenuates development phase of METH-induced behavioral sensitization through the PP2A/B - AKT cascade in the DS.

MicroRNA-31-3p/RhoA signaling in the dorsal hippocampus modulates methamphetamine-induced conditioned place preference in mice.

RATIONALE: MicroRNAs (miRNAs) regulate neuroplasticity-related proteins and are implicated in methamphetamine (METH) addiction. RhoA is a small Rho GTPase that regulates synaptic plasticity and addictive behaviors. Nevertheless, the functional relationship between RhoA and upstream miRNAs of METH addiction remains unclear. OBJECTIVE: To explore the molecular biology and epigenetic mechanisms of the miR-31-3p/RhoA pathway in METH addiction. METHODS: RhoA protein and its potential upstream regulator, miR-31-3p, were detected. A dual luciferase reporter was employed to determine whether RhoA constituted a specific target of miR-31-3p. Following adeno-associated virus (AAV)-mediated knockdown or overexpression of miR-31-3p or RhoA in the dorsal hippocampus (dHIP), mice were subjected to conditioned place preference (CPP) to investigate the effects of miR-31-3p and RhoA on METH-induced addictive behaviors. RESULTS: RhoA protein was significantly decreased in the dHIP of CPP mice with a concomitant increase in miR-31-3p. RhoA was identified as a direct target of miR-31-3p. Knockdown of miR-31-3p in the dHIP was associated with increased RhoA protein and attenuation of METH-induced CPP. Conversely, overexpression of miR-31-3p was associated with decreased RhoA protein and enhancement of METH effects. Similarly, knockdown of RhoA in the dHIP enhanced METH-induced CPP, whereas RhoA overexpression attenuated the effects of METH. Parallel experiments using sucrose preference revealed that the effects of miR-31-3p/RhoA pathway modulation were specific to METH. CONCLUSIONS: Our findings indicate that the miR-31-3p/RhoA pathway in the dHIP modulates METH-induced CPP in mice. Our results highlight the potential role of epigenetics represented by non-coding RNAs in the treatment of METH addiction.

The role of caveolin-1 in the biofate and efficacy of anti-tumor drugs and their nano-drug delivery systems.

As one of the most important components of caveolae, caveolin-1 is involved in caveolae-mediated endocytosis and transcytosis pathways, and also plays a role in regulating the cell membrane cholesterol homeostasis and mediating signal transduction. In recent years, the relationship between the expression level of caveolin-1 in the tumor microenvironment and the prognostic effect of tumor treatment and drug treatment resistance has also been widely explored. In addition, the interplay between caveolin-1 and nano-drugs is bidirectional. Caveolin-1 could determine the intracellular biofate of specific nano-drugs, preventing from lysosomal degradation, and facilitate them penetrate into deeper site of tumors by transcytosis; while some nanocarriers could also affect caveolin-1 levels in tumor cells, thereby changing certain biophysical function of cells. This article reviews the role of caveolin-1 in tumor prognosis, chemotherapeutic drug resistance, antibody drug sensitivity, and nano-drug delivery, providing a reference for the further application of caveolin-1 in nano-drug delivery systems.

Dietary Supplementation with Compound Probiotics and Berberine Alters Piglet Production Performance and Fecal Microbiota.

This study was conducted to investigate the effects of dietary supplementation with compound probiotics and berberine (CPB) on growth performance, nutrient digestibility and fecal microflora in weaned piglets. A total of 200 piglets 35 days old were randomly allocated to 5 groups, 4 replications in each group, and 10 piglets in each replication. Group A was the basal diet; group B was supplemented with antibiotics and zinc oxide; groups C, D and E were supplemented with 0.06%, 0.12% and 0.18% CPB, respectively. The experimental period was 42 d. The results indicated that there were no significant differences in average daily feed intake (ADFI), average daily gain (ADG) and feed conversion rate (FCR) among five groups (p > 0.05). However, mortality, diarrhea and rejection rates in the control group were higher than that in other groups. CPB could increase protein digestibility and serum IgG content (p < 0.05), while it could decrease serum urea nitrogen content and alkaline phosphatase activity (p < 0.05). Analysis of fecal microbiota showed that the relative abundances of Bacteroides and Firmicutes were increased, while the relative abundances of opportunistic pathogens such as Spirochaetae and Protebactreria were dramatically decreased in piglets fed with CPB or antibiotics, compared with the control group. Furthermore, CPB intervention increased the relative abundances of Prevotella_9, Megasphaera and Prevotella_2, while decreased the relative abundance of Prevotellaceae_NK3B31_group. Correlation analysis revealed that there was good correlation between serum indexes and fecal microbiota. It was suggested that CPB might be a promising antibiotic alternative for improving piglet health and immunity, decreasing mortality by positively altering gut microbiota.

Nano-encapsulated tryptanthrin derivative for combined anticancer therapy via inhibiting indoleamine 2,3-dioxygenase and inducing immunogenic cell death.

Aim: We developed a polycaprolactone-based nanoparticle (NP) to encapsulate tryptanthrin derivative CY-1-4 and evaluated its antitumor efficacy. Materials & methods: CY-1-4 NPs were prepared and evaluated for their cytotoxicity and associated mechanisms, indoleamine 2,3-dioxygenase (IDO)-inhibitory ability, immunogenic cell death (ICD)-inducing ability and antitumor efficacy. Results: CY-1-4 NPs were 123 nm in size. In vitro experiments indicated that they could both induce ICD and inhibit IDO. In vivo studies indicated that a medium dose reduced 58% of the tumor burden in a B16-F10-bearing mouse model, decreased IDO expression in tumor tissues and regulated lymphocytes subsets in spleen and tumors. Conclusion: CY-1-4 is a potential antitumor candidate that could act as a single agent with combined functions of IDO inhibition and ICD induction.