Stabilizing *CO2 Intermediates at the Acidic Interface using Molecularly Dispersed Cobalt Phthalocyanine as Catalysts for CO2 Reduction.

CO2 electroreduction (CO2 R) operating in acidic media circumvents the problems of carbonate formation and CO2 crossover in neutral/alkaline electrolyzers. Alkali cations have been universally recognized as indispensable components for acidic CO2 R, while they cause the inevitable issue of salt precipitation. It is therefore desirable to realize alkali-cation-free CO2 R in pure acid. However, without alkali cations, stabilizing *CO2 intermediates by catalyst itself at the acidic interface poses as a challenge. Herein, we first demonstrate that a carbon nanotube-supported molecularly dispersed cobalt phthalocyanine (CoPc@CNT) catalyst provides the Co single-atom active site with energetically localized d states to strengthen the adsorbate-surface interactions, which stabilizes *CO2 intermediates at the acidic interface (pH=1). As a result, we realize CO2 conversion to CO in pure acid with a faradaic efficiency of 60 % at pH=2 in flow cell. Furthermore, CO2 is successfully converted in cation exchanged membrane-based electrode assembly with a faradaic efficiency of 73 %. For CoPc@CNT, acidic conditions also promote the intrinsic activity of CO2 R compared to alkaline conditions, since the potential-limiting step, *CO2 to *COOH, is pH-dependent. This work provides a new understanding for the stabilization of reaction intermediates and facilitates the designs of catalysts and devices for acidic CO2 R.

Nitrogen and bromine co-doped carbon dots with red fluorescence for sensing of Ag+ and visual monitoring of glutathione in cells.

Carbon dots (CDs) with red fluorescence emission have excellent advantages in cell imaging. Herein, novel nitrogen and bromine doped CDs (N,Br-CDs) were prepared with 4-bromo-1,2-phenylenediamine as precursor. The N, Br-CDs present the optimal emission wavelength at 582 nm (λex = 510 nm) at pH 7.0 and 648 nm (λex = 580 nm) at pH 3.0 âˆ¼ 5.0, respectively. The fluorescence intensity of N,Br-CDs at 648 nm versus Ag+ concentration shows a good relationship from 0 to 60 µM with the limit of detection (LOD) of 0.14 µM. Furthermore, the fluorescence of N,Br-CDs/Ag+ is efficiently restored via the combination of glutathione (GSH) and Ag+ and linearly changes with GSH concentration from 0 âˆ¼ 6.0 µM with LOD of 49 nM. This method has been successfully employed to monitor intracellular Ag+ and GSH with fluorescence imaging. The results suggest that the N,Br-CDs has application potential in the sensing of Ag+ and visual monitoring of GSH in cells.

ERK/mTOR signaling may underlying the antidepressant actions of rapastinel in mice.

Rapastinel as the allosteric modulator of N-methyl-D-aspartate receptor (NMDAR) produces rapid antidepressant-like effects dependent on brain-derived neurotrophic factor (BDNF) and VGF (nonacryonimic) release. Herein, we further explore the molecular mechanisms of the antidepressant effects of repeated administration with rapastinel in mice. Our results showed that continuous 3-day rapastinel (5 and 10 mg/kg, i.v.) produced antidepressant-like actions dependent on the increase in extracellular regulated protein kinase (ERK)/mammalian target of rapamycin (mTOR) signaling and downstream substrates p70S6 kinase (p70S6k) and the eukaryotic initiation factor 4E-binding protein 1 (4E-BP1), which may induce the expression of VGF and BDNF in the hippocampus and prefrontal cortex of mice. Furthermore, compared with a single treatment, our data indicated that 3-day repeated rapastinel treatment produced antidepressant-like actions accompanied by potentiation of ERK/mTOR/VGF/BDNF/tropomyosin-related kinase receptor B (TrkB) signaling. Based on previous and our supplementary data that showed the pivotal role of on α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) in the rapid release of VGF and BDNF and activation of TrkB by a single dose of rapastinel, we postulate that the antidepressant-like effects of single or repeated administration of rapastinel may result in the rapid release of VGF and BDNF or ERK/mTOR signaling pathway-mediated VGF/BDNF/TrkB autoregulatory feedback loop respectively. Our current work adds new knowledge to the molecular mechanisms that underlie the antidepressant-like actions of rapastinel in mice.

The Regulation of Glutamate Transporter 1 in the Rapid Antidepressant-Like Effect of Ketamine in Mice.

Accumulating evidence suggests that glutamate clearance plays a critical role in the pathophysiology and treatment of depression. Preclinical and clinical studies have demonstrated that ketamine provides an immediate and sustained antidepressant effect. However, the precise mechanism of its action remains to be elucidated. Glutamate transporter 1 (GLT1) participates in glutamate clearance; therefore, we hypothesized that GLT1 may play an important role in the antidepressant effect of ketamine. In this study, we determined that GLT1 inhibition blocks the antidepressant-like properties of ketamine and alters the phosphorylation of the mammalian target of rapamycin (mTOR) in the prefrontal cortex (PFC). Our results show that pretreatment with dihydrokainic acid (DHK), a GLT1 inhibitor, alleviated the antidepressant-like effect of ketamine, and decreased the level of phosphorylated mTOR (pmTOR) in mice (which is normally upregulated by ketamine). In addition, inhibition of α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptor and L-type voltage-dependent calcium channel (L-VDCC) significantly abolished the antidepressant-like effect of ketamine. Moreover, inhibition of L-VDCC significantly blocked the upregulation of GLT1 and BDNF in the PFC of mice. The inhibition of the AMPA receptor only significantly alleviated BDNF. Our results provide insight into the role of GLT1 as the critical presynaptic molecule participating in the pathophysiological mechanism of depression and contributing to the antidepressant-like effect of ketamine. In addition, our study confirms that both AMPA receptor and L-VDCC are crucial factors in the immediate antidepressant-like effect of ketamine.

Assessment of a new arbidol derivative against herpes simplex virus II in human cervical epithelial cells and in BALB/c mice.

As one of the highly contagious forms, herpes simplex virus type 2 (HSV-2) commonly caused severe genital diseases and closely referred to the HIV infection. The lack of effective vaccines and drug-resistance proclaimed the preoccupation for alternative antiviral agents against HSV-2. Molecules bearing indole nucleus presented diverse biological properties involving antiviral and anti-inflammatory activities. In this study, one of the indole molecules, arbidol derivative (ARD) was designed and synthesized prior to the evaluation of its anti-HSV-2 activity. Our data showed that the ARD effectively suppressed HSV-2-induced cytopathic effects and the generation of progeny virus, with 50% effective concentrations of 3.386 and 1.717 µg/mL, respectively. The results of the time-course assay suggested that the ARD operated in a dual antiviral way by interfering virus entry and impairing the earlier period of viral cycle during viral DNA synthesis. The ARD-mediated HSV-2 inhibition was partially attained by blocking NF-κB pathways and down-regulating the expressions of several inflammatory cytokines. Furthermore, in vivo studies showed that oral administration of ARD protected BALB/c mice from intravaginal HSV-2 challenge by alleviating serious vulval lesions and histopathological changes in the target organs. Besides, the treatment with ARD also made the levels of viral protein, NF-κB protein and inflammatory cytokines lower, in consistent with the in-vitro studies. Collectively, ARD unveiled therapeutic potential for the prevention and treatment of HSV-2 infections.

Antiviral Properties of R. tanguticum Nanoparticles on Herpes Simplex Virus Type I In Vitro and In Vivo.

Herpes simplex virus type 1 (HSV-1), an enveloped DNA virus, plays a key role in varieties of diseases including recurrent cold sores, keratoconjunctivitis, genital herpes and encephalitis in humans. Great efforts have been made in developing more effective and less side-effects anti-herpes simplex virus agents, including traditional Chinese herbal medicines. In the present study, we evaluated the antiviral efficacy of Rheum tanguticum nanoparticles against HSV-1 in vitro and in vivo. R. tanguticum nanoparticles could inactivate the HSV-1 virions and block the viral attachment and entry into cells. Time-of-addition assay indicated that R. tanguticum nanoparticles could interfere with the entire phase of viral replication. Besides, R. tanguticum nanoparticles showed the ability to inhibit the mRNA expression of HSV-1 immediate early gene ICP4 and early gene ICP8 as well as the expression of viral protein ICP4 and ICP8. Moreover, R. tanguticum nanoparticles have been proved to protect mice against HSV-1 induced lethality by decreasing the viral load and alleviated pathological changes in brain tissues. In conclusion, we demonstrated that R. tanguticum nanoparticles could inhibit HSV-1 infection through multiple mechanisms. These results suggest that R. tanguticum nanoparticles may have novel roles in the treatment of HSV-1 infection.

BDNF mediates the protective effects of scopolamine in reserpine-induced depression-like behaviors via up-regulation of 5-HTT and TPH1.

Reserpine treatment in rodents has been shown to induce depression-like behaviors that mimic monoamine dysfunction implicated in the development of depression. Herein, we aimed to demonstrate the antidepressant-like activities of scopolamine, the muscarinic receptor antagonist, in a reserpine-induced mouse model. Mice were injected with 1.5 mg/kg (i.p.) of reserpine for 10 days, and the depression-like state was confirmed via the open field test (OFT) and forced swimming test (FST). Then, the mice were treated with scopolamine (25 µg/kg, i.p.) or saline for 3 days. Ten days of reserpine treatment resulted in a significant decrease in locomotor activity and an increase in immobility time in the OFT and FST, respectively, indicating that ten days of reserpine administration significantly induced depression-like behaviors in mice. However, scopolamine rapidly ameliorated the increase in immobility time in the FST and had no effect on locomotor activity in the OFT. In addition, the reserpine-induced decreases in serotonin transporter (5-HTT), brain-derived neurotrophic factor (BDNF) and tryptophan hydroxylase 1 (TPH1) in mouse hippocampus and prefrontal cortex (PFC) were significantly reversed by scopolamine. Our study provides evidence that scopolamine rapidly attenuates reserpine-induced depression in mice partially by regulating 5-HTT, BDNF and TPH1 in the hippocampus and PFC of mice.

Positive Allosteric Modulation of AMPAR by PF-4778574 Produced Rapid Onset Antidepressant Actions in Mice.

It has been reported that fast-acting antidepressants enhance glutamatergic neurotransmission in the prefrontal cortex (PFC) regions via alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) activation. However, the precise mechanisms underlying the fast-acting antidepressants lead to an activation of AMPAR pathways remain largely unclear. To address this issue, a novel AMPAR positive allosteric agonist, PF-4778574, was used to test the rapid effects and the role of VGF (nonacronymic)/brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase B (TrkB)/AKT signaling in these actions in mice. We found that PF-4778574 rapidly alleviated chronic unpredictable stress-induced depression-like behaviors in a concentration-dependent manner. In addition, knock down of vesicular glutamate transporter 1 (VGLUT1) in the PFC of mice induced depression-like behaviors, whereas treatment with PF-4778574 was sufficient to alleviate it, indicating a presynaptic VGLUT1 independent effect. Furthermore, we demonstrate that pharmacological inhibitors of AMPAR or of L-type voltage-dependent Ca2+ channel (L-VDCC) blocked the antidepressants' effect on behaviors and the upregulation on the AMPAR-mediated VGF/BDNF/TrkB/AKT signaling of PF-4778574. Together, our findings indicate that postsynaptic AMPAR activation followed by activation of L-VDCC and subsequent VGF/BDNF/TrkB/AKT signaling are required for the rapid antidepressant effects of PF-4778574. Our data support a promising therapeutic profile for PF-4778574 as a new fast-acting antidepressant.

Mechanisms underlying the rapid-acting antidepressant-like effects of neuropeptide VGF (non-acronymic) C-terminal peptide TLQP-62.

Previous studies have revealed that neuropeptide VGF (non-acronymic) C-terminal peptide TLQP-62 rapidly activates brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase B (TrkB)/α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor/mammalian target of rapamycin (mTOR) signaling and produces antidepressant-like actions in rodents. In addition, acute TLQP-62 infusion also markedly changes the AMPA receptor GluA1 subunit phosphorylation at Ser 845 (pGluA1 Ser845) in the PFC of mice, indicating that the GluA1 may contributes to the rapid antidepressant-like effects of TLQP-62. However, how to regulate the TrkB-mediated signaling and GluA1 changes in the prefrontal cortex (PFC) by TLQP-62 remains unclear. Herein, acute administration of TLQP-62 into PFC produced rapid-acting antidepressant-like effects in mice. Additionally, we confirmed that TLQP-62 ameliorated the depression-like behaviors induced by chronic social defeat stress (CSDS) in mice. Further investigation demonstrated that this effect of TLQP-62 was mediated by activation of TrkB and mTOR, which proceeded to decrease bicaudal C homolog 1 gene (BICC1) and increase synaptic protein expression, including GluA1 subunit and pGluA1 Ser845. Notably, we further found that beneficial effects of TLQP-62 on depression-like behaviors and TrkB/mTOR/BICC1 signaling, GluA1 phosphorylation and GluA1 activation in the PFC of mice were significantly abolished by TrkB antagonist ANA-12. In conclusion, our findings indicate that TrkB/mTOR/BICC1 signaling, GluA1 phosphorylation and GluA1 activation in the PFC may involve in the rapid-acting antidepressant-like actions of TLQP-62 in mice.

Essential roles of neuropeptide VGF regulated TrkB/mTOR/BICC1 signaling and phosphorylation of AMPA receptor subunit GluA1 in the rapid antidepressant-like actions of ketamine in mice.

Previous studies have suggested that rapid reductions in depression-like behaviors are observed in response to sub-anesthetic-doses of ketamine, an N-methyl-d-aspartate receptor (NMDAR) antagonist. Neuropeptide VGF (non-acronymic) is a critical effector of depression-like behaviors and is thought to be involved in the antidepressant actions of ketamine that have been demonstrated. However, the mechanism underlying the involvement of VGF in the anti-depressant action of ketamine remains unclear. We found that single dose ketamine treatment reversed CSDS-induced depression-like behaviors and decrease of VGF in the PFC of mice. To investigate the involvement of VGF in the antidepressant-like effects of ketamine, a lentivirus vector for VGF was constructed to knockdown the expression of VGF in the prefrontal cortex (PFC) of mice. The biochemical and behavioral effects of this VGF knockdown were examined, using the open field, forced swim, and sucrose preference tests. Our results show that knockdown of VGF increased the immobility time and decreased the sucrose preference in mice. These effects were not improved by ketamine administration. In addition, we found that knockdown of VGF significantly decreased the expression of phosphorylation of tropomyosin receptor kinase B (TrkB), mammalian target of rapamycin (mTOR), and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit GluA1 Ser845 and increased the expression of bicaudal C homolog 1 (BICC1) in the mouse PFC, and blocked the regulation of TrkB/mTOR/BICC1 signaling and GluA1 phosphorylation by ketamine. Our results indicate that the rapid onset antidepressant-like actions of ketamine require VGF to regulate TrkB/mTOR/BICC1 signaling and AMPA receptor GluA1 phosphorylation.

Antiviral activity of arbidol hydrochloride against herpes simplex virus I in vitro and in vivo.

Herpes simplex virus type 1 (HSV-1) causes significant human diseases ranging from skin lesions to encephalitis, especially in neonates and immunocompromised hosts. The discovery of novel anti-HSV-1 drugs with low toxicity is required for public health. Arbidol hydrochloride (ARB) is an indole derivative molecule with broad-spectrum antiviral activity. In this study, the antiviral effects of ARB against HSV-1 infection were evaluated in vitro and in vivo. The results showed that ARB presents significant inhibitory effect on HSV-1 plaque formation and generation of progeny virus, with EC50 values (50% effective concentration) of 5.39 µg/mL (10.49 µM) and 2.26 µg/mL (4.40 µM), respectively. Moreover, time-of-addition and time-of-removal assays further suggested that ARB has viral inhibitory effects when added up to 12 h post-infection (p.i.), which could be further corroborated by determining the expression of viral immediate-early (ICP4, ICP22 and ICP27), early (ICP8 and UL42) and late (gB, gD, gH, VP1/2 and VP16) genes by real-time quantitative PCR as well as the expression of viral protein ICP4 and ICP8 at 6 h and 12 h p.i. Results of the in vivo study showed that ARB could reduce guinea pig skin lesions caused by HSV-1 infection. Conclusively, this report offers new perspectives in the search for therapeutic measures in the treatment of HSV-1 infection.

Vesicular glutamate transporter 1 (VGLUT1)-mediated glutamate release and membrane GluA1 activation is involved in the rapid antidepressant-like effects of scopolamine in mice.

Emerging data have identified certain drugs such as scopolamine as rapidly acting antidepressants for major depressive disorder (MDD) that increase glutamate release and induce neurotrophic factors through α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) activation in rodent models. However, little research has addressed the direct mechanisms of scopolamine on AMPAR activation or vesicular glutamate transporter 1 (VGLUT1)-mediated glutamate release in the prefrontal cortex (PFC) of mice. Herein, using a chronic unpredictable stress (CUS) paradigm, acute treatment with scopolamine rapidly reversed stress-induced depression-like behaviors in mice. Our results showed that CUS-induced depression-like behaviors, accompanied by a decrease in membrane AMPAR subunit 1 (GluA1), phosphorylated GluA1 Ser845 (pGluA1 Ser845), brain-derived neurotrophic factor (BDNF) and VGF (non-acronymic) and an increase in bicaudal C homolog 1 gene (BICC1) in the PFC of mice, and these biochemical and behavioral abnormalities were ameliorated by acute scopolamine treatments. However, pharmacological block of AMPAR by NBQX infusion into the PFC significantly abolished these effects of scopolamine. In addition, knock down of VGLUT1 by lentiviral-mediated RNA interference in the PFC of mice was sufficient to induce depression-like phenotype, to decrease extracellular glutamate accumulation and to cause similar molecular changes with CUS in mice. Remarkably, VGLUT1 knockdown alleviated the rapid antidepressant-like actions of scopolamine and the effects of scopolamine on membrane GluA1-mediated BDNF, VGF and BICC1 changes. Altogether, our findings suggest that VGLUT1-mediated glutamate release and membrane GluA1 activation may play a critical role in the rapid-acting antidepressant-like effects of scopolamine in mice.

Specific interference shRNA-expressing plasmids inhibit Hantaan virus infection in vitro and in vivo.

AIM: To investigate the antiviral effects of vectors expressing specific short hairpin RNAs (shRNAs) against Hantaan virus (HTNV) infection in vitro and in vivo. METHODS: Based on the effects of 4 shRNAs targeting different regions of HTNV genomic RNA on viral replication, the most effective RNA interference fragments of the S and M genes were constructed in pSilencer-3.0-H1 vectors, and designated pSilencer-S and pSilencer-M, respectively. The antiviral effect of pSilencer-S/M against HTNV was evaluated in both HTNV-infected Vero-E6 cells and mice. RESULTS: In HTNV-infected Vero-E6 cells, pSilencer-S and pSilencer-M targeted the viral nucleocapsid proteins and envelope glycoproteins, respectively, as revealed in the immunofluorescence assay. Transfection with pSilencer-S or pSilencer-M (1, 2, 4 µg) markedly inhibited the viral antigen expression in dose- and time-dependent manners. Transfection with either plasmid (2 µg) significantly decreased HTNV-RNA level at 3 day postinfectin (dpi) and the progeny virus titer at 5 dpi. In mice infected with lethal doses of HTNV, intraperitoneal injection of pSilencer-S or pSilencer-M (30 µg) considerably increased the survival rates and mean time to death, and significantly reduced the mean virus yields and viral RNA level, and alleviated virus-induced pathological lesions in lungs, brains and kidneys. CONCLUSION: Plasmid-based shRNAs potently inhibit HTNV replication in vitro and in vivo. Our results provide a basis for development of shRNA as therapeutics for HTNV infections in humans.